573 research outputs found

    Experiments in cooking poultry for pre-cooked poultry products : cooking fowl with various salts and in plastic containers

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    The bulletin is a report on the Department of Poultry Husbandry Project 323, 'Methods of Processing Poultry for Commercial Pre-cooked Frozen and Canned Products'--P. [2].Digitized 2007 AES.Includes bibliographical references (page 18)

    Synthesis and Crystal Structures of New 5,5'-Azotetrazolates

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    Five new 5,5'-azotetrazolate salts (amminsilver, trimethylsulfonium, tetramethyl-phosphonium, trimethylsulfoxonium, 2-(hydroxyethyl)trimethylammonium) were prepared and characterized. The crystal structures were determined by X-ray diffraction. Interactions between the ions are identified and discussed. The sensitivities of the highly energetic silver salt were measured by BAM (Bundesanstalt für Materialforschung und-prüfung) methods

    Comparison of ultracold neutron sources for fundamental physics measurements

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    Ultracold neutrons (UCNs) are key for precision studies of fundamental parameters of the neutron and in searches for new CP violating processes or exotic interactions beyond the Standard Model of particle physics. The most prominent example is the search for a permanent electric dipole moment of the neutron (nEDM). We have performed an experimental comparison of the leading UCN sources currently operating. We have used a 'standard' UCN storage bottle with a volume of 32 liters, comparable in size to nEDM experiments, which allows us to compare the UCN density available at a given beam port.Comment: 20 pages, 30 Figure

    Cancrinite-group minerals behavior at non-ambient conditions

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    Cancrinite-group minerals occur in the late stages of alkaline (SiO2)-undersaturated magmatism and in related effusive or contact rocks. So far only few studies have been devoted to the description of the thermo-elastic behavior,phase-stability and P /T -structure evolution (at the atomic scale) of this mineral group. Cancrinite-group minerals have an open-framework structure characterized by the [CAN]-topology. The [CAN]-framework shows large 12-ring channels, parallel to the c crystallographic axis, bound by columns of cages, the so-called can units. While very limited chemical variation is observed in the framework composition (the composition is almost always [Si6Al6O24]) a remarkable chemical variability is reported for the extraframework components in the cancrinite-group minerals. Two subgroups can be identified according to the extraframework content of the can units: the cancrinite- and the davyne-subgroups, showing Na-H2O and Ca-Cl chains, respectively. The channels are stuffed by cations, anions and molecules. We aimed to model the thermo-elastic behavior and the mechanisms of the (P ,T )-induced structure evolution of cancrinite-group minerals, with special interest on the role played by the extraframework population. The study was restricted to the following (CO3)-rich and (SO4)-rich end-members: cancrinite sensu stricto {[(Na,Ca)6(CO3)1.2 121.7][Na2(H2O)2][Al6Si6O24]}, vishnevite {[(Na,Ca,K)6(SO4)][Na2(H2O)2][Al6Si6O24]}, balliranoite {[(Na,Ca)6(CO3)1.2 121.7][Ca2Cl2][Al6Si6O24]} and davyne {[(Na,Ca,K)6((SO4),Cl)][Ca2Cl2][Al6Si6O24]}. Their high-P and low-T (T < 293 K) behavior was investigated by means of in-situ single-crystal X-ray diffraction, using diamond-anvil cells and (N2)-cryosystems, respectively. The high-T behavior of cancrinite has also been studied by means of in-situ single-crystal X-ray diffraction with a resistive heater. Cancrinite minerals share a similar volume compressibility and thermal expansivity at ambient conditions (cancrinite has KV0 = 45(2) GPa and \u3b1V,293K = 4.88(8)\ub710 125 K 121; vishnevite has KV0 = 49(2) GPa; balliranoite has KV0 = 48(3) GPa and \u3b1V,293K = 4.6(4)\ub710 125 K 121; davyne has KV0 = 46.5(11) GPa and \u3b1V,293K = 4.2(4)\ub710 125 K 121). However, these minerals show different thermo-elastic anisotropy schemes, more pronounced in the cancrinite-subgroup minerals. This behavior is governed by different deformation mechanisms of the crystal structure, which likely reflect the different coordination environments of the cage-cations between the minerals of the cancrinite-and davyne-subgroups (i.e. Na+ and Ca2+, respectively). In addition, a P -induced re-organization of the extraframework population is observed, in vishnevite, at P 65 3.5 GPa, suggesting that the channel-constituents can also affect the elastic and structural behavior and the phase stability of these minerals at non-ambient conditions. Besides common features likely ascribable to the [CAN]-topology, the nature of the extraframework population appears to control significantly the (P ,T )-induced structure evolution and thermo-elastic behavior of the cancrinite-group compounds. PL, GDG and MM acknowledge the Italian Ministry of Education, MIUR-Project: \u201cFuturo in Ricerca 2012 - ImPACT- RBFR12CLQD\u201d. MA acknowledges the ERC starting grant N. 307322 to FN

    Extensive sequential polymorphic interconversion in the solid-state: Two hydrates and ten anhydrous phases of hexamidine diisethionate

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    Crystal polymorphism and solvent inclusion is a dominant research area in the pharmaceutical industry and continues to unveil complex systems. Here, we present the solid-state system of hexamidine diisethionate (HDI), an antiseptic drug compound forming a dimorphic dihydrate as well as ten anhydrous polymorphs. The X-ray and neutron crystal structures of the hydrated crystal forms and related interaction energies show no direct interaction between the cation and water but very strong interactions between cation and anion, and anion and water. This is observed macroscopically as high stability of the hydrate against dehydration by temperature and humidity. The anhydrous polymorphs reveal a rare case of sequential and reversible polymorphic transformations, which are characterized by thermal analysis and variable-temperature powder X-ray diffraction (PXRD). While most transitions are accompanied by significant structural changes, the low-energy transitions can only be detected as slight changes in the reflection positions with temperature. HDI thus represents a model compound to investigate polymorphic transitions with small structural changes

    Accelerated discovery of two crystal structure types in a complex inorganic phase field

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    The discovery of new materials is hampered by the lack of efficient approaches to the exploration of both the large number of possible elemental compositions for such materials, and of the candidate structures at each composition1. For example, the discovery of inorganic extended solid structures has relied on knowledge of crystal chemistry coupled with time-consuming materials synthesis with systematically varied elemental ratios2,3. Computational methods have been developed to guide synthesis by predicting structures at specific compositions4,5,6 and predicting compositions for known crystal structures7,8, with notable successes9,10. However, the challenge of finding qualitatively new, experimentally realizable compounds, with crystal structures where the unit cell and the atom positions within it differ from known structures, remains for compositionally complex systems. Many valuable properties arise from substitution into known crystal structures, but materials discovery using this approach alone risks both missing best-in-class performance and attempting design with incomplete knowledge8,11. Here we report the experimental discovery of two structure types by computational identification of the region of a complex inorganic phase field that contains them. This is achieved by computing probe structures that capture the chemical and structural diversity of the system and whose energies can be ranked against combinations of currently known materials. Subsequent experimental exploration of the lowest-energy regions of the computed phase diagram affords two materials with previously unreported crystal structures featuring unusual structural motifs. This approach will accelerate the systematic discovery of new materials in complex compositional spaces by efficiently guiding synthesis and enhancing the predictive power of the computational tools through expansion of the knowledge base underpinning them

    τ\tauSPECT: A spin-flip loaded magnetic ultracold neutron trap for a determination of the neutron lifetime

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    The confinement of ultracold neutrons (UCNs) in a three dimensional magnetic field gradient trap allows for a measurement of the free neutron lifetime with superior control over spurious loss channels and can provide a large kinetic energy acceptance to enhance statistical sensitivity. In this paper, we present the first successful implementation of a pulsed spin-flip based loading scheme for a three-dimensional magnetic UCN trap. The measurements with the τ\tauSPECT experiment were performed at the pulsed UCN source of the research reactor TRIGA Mainz. We report on detailed investigations of major systematic effects influencing the neutron storage time, statistically limited by the size of the recorded data set. The extracted neutron storage time constant of τ=859(16)s\tau = 859(16)\mathrm{s} is compatible with, but not to be interpreted as, a measurement of the free neutron lifetime.Comment: 15 pages, 19 figure

    The Mechanism Design Approach to Student Assignment

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    The mechanism design approach to student assignment involves the theoretical, empirical, and experimental study of systems used to allocate students into schools around the world. Recent practical experience designing systems for student assignment has raised new theoretical questions for the theory of matching and assignment. This article reviews some of this recent literature, highlighting how issues from the field motivated theoretical developments and emphasizing how the dialogue may be a road map for other areas of applied mechanism design. Finally, it concludes with some open questions.National Science Foundation (U.S.
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