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Wyniki wyszukiwania dla: NEUTRON
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Neutron News
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/sup 6/LiI(Eu) in neutron and /spl gamma/-ray spectrometry-a highly sensitive thermal neutron detector
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Journal of Neutron Research
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Some application of neutron activation analysis: A Review
PublikacjaW pracy przedstawiono podstawowe informacje dotyczące neutronowej analizy aktywacyjnej. Przedstawiono również zastosowanie neutronowej analizy aktywacyjnej w badaniu próbek środowiskowych i biologicznych wraz z krótkim omówieniem wyników. Poruszono także aspekt zapewnienia jakości i kontroli wyników analitycznych otrzymywanych tą metodą.
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Numerical solution of fractional neutron point kinetics in nuclear reactor
PublikacjaThis paper presents results concerning solutions of the fractional neutron point kinetics model for a nuclear reactor. Proposed model consists of a bilinear system of fractional and ordinary differential equations. Three methods to solve the model are presented and compared. The first one entails application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. Second involves building an analog scheme...
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Lattice dynamics of HgSe: Neutron scattering measurements andab initiostudies
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Development of a digital method for neutron/gamma-ray discrimination based on matched filtering
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Fractional neutron point kinetics equations for nuclear reactor dynamics – Numerical solution investigations
PublikacjaThis paper presents results concerning numerical solutions to a fractional neutron point kinetics model for a nuclear reactor. The paper discusses and expands on results presented in (Espinosa-Paredes et al., 2011). The fractional neutron point kinetics model with six groups of delayed neutron precursors was developed and a numerical solution using the Edwards’ method was proposed (Edwards et al., 2002). The mathematical model...
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High-density polyethylene/EPDM rubber blend composites of boron compounds for neutron shielding application
PublikacjaNovel materials with neutron shielding property were fabricated by incorporating boron compounds into highdensity polyethylene (HDPE)/Ethylene propylene diene monomer rubber (EPDM) blends. A detailed investigation on the morphological, thermal, mechanical, and neutron attenuation properties of suitable proportion of HDPE/EPDM blend with boric acid (BA), boron carbide (BC), and nano boron carbide (NBC) were performed. Morphology...
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Anomalous pressure dependence of acoustic phonons of AgGaSe2 investigated by inelastic neutron scattering to 4.3 GPa
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SmallAngle Neutron Scattering Study of the Structure of Mixed Micellar Solutions Based on Nonionic and Two Cationic Surfactants
PublikacjaThe aggregation in mixed water systems based on nonionic surfactant, i.e., heptaethylene glycol monotetradecyl ether (C14E7), and cationic surfactants, i.e., cetyltrimethylammonium bromide (CTAB), and cetyltrimethylammonium chloride (CTAC) has been investigated using the smallangle neutron scattering method. The preliminary results of the study of the behavior of C14E7 aqueous solutions (for a concentration of 0.17%) when adding...
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Numerical model of human head phantom to ensure dosimetry of dose components for boron neutron capture therapy
PublikacjaExtremely important aspects of the boron neutron capture therapy are, first of all, administering to the patient a boron compound that selectively reaches the neoplastic cells, and in the second step, the verification of the irradiation process. This paper focuses on the latter aspect, which is the detailed dosimetry of the processes occurring after the reaction of thermal neutrons with the boron-10 isotope. The results of computer...
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Oxygen release from BaLnMn2O6 (Ln: Pr, Nd, Y) under reducing conditions as studied by neutron diffraction
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Small-Angle Neutron Scattering Study of the Structure of Mixed Micellar Solutions Based on Heptaethylene Glycol Monotetradecyl Ether and Cesium Dodecyl Sulfate
PublikacjaThe micellization in mixed aqueous systems based on a nonionic surfactant, heptaethylene glycol monotetradecyl ether (C14E7), and an anionic surfactant, cesium dodecyl sulfate, has been investigated by small-angle neutron scattering. Preliminary data on the behavior of the C14E7 aqueous solutions (with three concentrations, 0.17, 0.5, and 1%) mixed with a small amount of anionic surfactant, cesium dodecyl sulfate, are reported.
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Journal of Surface Investigation-X-Ray Synchrotron and Neutron Techniques
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A study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and sodium (lithium) dodecyl sulfate by the small-angle neutron scattering method
PublikacjaZbadano micelizację w układach mieszanych bazujących na nowym surfaktancie niejonowym, heptaoksyetylenowanym alkoholu tetradecylowym (C14E7) i surfaktantach anionowych, dodecylosiarczanie sodu, decylosiarcznie sodu oraz dodecylosiarcznie litu za pomocą metody niskokątowego rozproszenia neutronów.Przedstawione zostały wstępne wyniki zachowania wodnych roztworów C14E7 (o dwóch stężeniach 0,17 i 0,50%) przy niewielkim udziale trzech...
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Elemental composition analysis of Pistacia lentiscus L., leaves collected from Mitidja plain in Algeria using instrumental neutron activation analysis (INAA) technique
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WYDAJNE ŹRÓDŁA NEUTRONÓW
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Magnetyczne metody diagnozowania stali napromieniowanych neutronami
PublikacjaOpisano magnetyczne metody diagnozowania stali napromieniowanych neutronami
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Detection of neutrons with LiF fluorescent nuclear track detectors
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Naukowcy pracują nad poprawą efektywności terapii borowo-neutronowej w chorobach nowotworowych
PublikacjaBadacze konsorcjum zamierzają wspólnie wypracować nowatorską metodologię, która znacznie poprawi kliniczną efektywność terapii boro- wo-neutronowej chorób nowotworowych. Technologia wypracowana przez konsorcjum stanie się podstawą nowych produktów i usług dla klinik onkologicznych w skali globalnej.
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Thermoluminescent response of differently doped lithium magnesium phosphate (LiMgPO4, LMP) crystals to protons, neutrons and alpha particles
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Application of low-cost Gallium Arsenide light-emitting-diodes as kerma dosemeter and fluence monitor for high-energy neutrons
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Accidental wow evaluation based on sinusoidal modeling and neural nets prediction
PublikacjaReferat przedstawia opis algorytmu do określenia charakterystyki zniekształcenia kołysania dźwięku. Prezentowane podejście wykorzystuje sinusoidalną analizę dźwięku bazującą zarówno na amplitudowym jak i fazowym widmie sygnału fonicznego. Trajektorie poszczególnych składowych tonalnych, obrazujące zniekształcenie kołysania, określane są na podstawie analizy ich chwilowych amplitud, częstotliwości i faz. Dodatkowo referat przedstawia...
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USŁUGA RÓWNOWAŻENIA OBCIĄŻENIA W SYSTEMIE OPENSTACK
PublikacjaNiniejszy artykuł ma na celu pokazanie funkcjonowania równoważenia obciążenia dla serwisu Neutron odpowiedzialnego za tworzenie i obsługę usług sieciowych dla użytkowników OpenStack’a. Stanowi on podstawę do zapewnienia komunikacji wewnątrz systemowej, z systemem jak i z wewnętrznymi prywatnymi sieciami systemowymi. W artykule przedstawiono wyniki bazując na edycji Juno, którą zaimplementowano w celu przeprowadzenia badań i analizy...
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Antimony substituted lanthanum orthoniobate proton conductor – structure and electronic properties.
PublikacjaX‐ray and neutron diffraction have been utilized to analyze the crystalline and electronic structure of lanthanum orthoniobate substituted by antimony. Using X‐ray absorption spectroscopy and photoelectron spectroscopy, changes in the electronic structure of the material upon substitution have been analyzed. The structural transition temperature between fergusonite and scheelite phases for 30 mol% antimony substitution was found...
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Nodal models of Pressurized Water Reactor core for control purposes – A comparison study
PublikacjaThe paper focuses on the presentation and comparison of basic nodal and expanded multi-nodal models of the Pressurized Water Reactor (PWR) core, which includes neutron kinetics, heat transfer between fuel and coolant, and internal and external reactivity feedback processes. In the expanded multi-nodal model, the authors introduce a novel approach to the implementation of thermal power distribution phenomena into the multi-node...
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Evidence for SrHo2O4 and SrDy2O4 as model J1- J2 zigzag chain materials
PublikacjaNeutron diffraction and inelastic spectroscopy is used to characterize the magnetic Hamiltonian of SrHo2O4 and SrDy2O4. Through a detailed computation of the crystal-field levels we find site-dependent anisotropic single-ion magnetism in both materials, and diffraction measurements show the presence of strong one-dimensional spin correlations.Our measurements indicate that competing interactions of the zigzag chain, combinedwith...
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Numerical solution analysis of fractional point kinetics and heat exchange in nuclear reactor
PublikacjaThe paper presents the neutron point kinetics and heat exchange models for the nuclear reactor. The models consist of a nonlinear system of fractional ordinary differential and algebraic equations. Two numerical algorithms are used to solve them. The first algorithm is application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. The second involves building an analog scheme in the FOMCON Toolbox...
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Rheological, Mechanical, Microstructural and Radiation Shielding Properties of Cement Pastes Containing Magnetite (Fe3O4) Nanoparticles
PublikacjaThis work examines the influence of iron oxide nanoparticles (Fe3O4 NPs) on neutron and gamma-ray radiation shielding characteristics of Portland cement paste. Experimental evaluations were supplemented with theoretical studies using NXCom program. Portland cement pastes with 5, 10, 15, 20, and 30 wt% of nanomagnetite cement replacement were produced. Moreover, rheological, early strength development, compressive strength, and...
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Charge density wave and crystalline electric field effects in TmNiC2
PublikacjaSingle crystals of TmNiC2 were grown by the optical floating-zone technique and were investigated by x-ray diffraction (XRD), thermal expansion, electrical resistivity, specific heat, and magnetic susceptibility measurements. Single-crystal XRD reveals the formation of a commensurate charge density wave (CDW) characterized by a CDW modulation vector q2c = (0.5, 0.5, 0.5), which is accompanied by a symmetry change from the orthorhombic...
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Mechanical and radiation shielding properties of concrete reinforced with boron--basalt fibers using Digital Image Correlation and X--ray micro--computed tomography
PublikacjaThe paper presents experimental investigations of the radiation shielding, mechanical and fracture properties of concrete reinforced with 5 kg/m3 of novel basalt fibers infused with boron oxide (BBF). However, further studies concerning other dosages i.e. 1 kg/m3, 10 kg/m3, 15 kg/m3 and 20 kg/m3 are currently carried out. Experiments with neutron source revealed that addition of BBF as a dispersed concrete reinforcement could improve...
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Real-Time Basic Principles Nuclear Reactor Simulator Based on Client-Server Network Architecture with WebBrowser as User Interface
PublikacjaThe real-time simulator of nuclear reactor basic processes (neutron kinetics, heat generation and its exchange, poisoning and burn- ing up fuel) build in a network environment is presented in this paper. The client-server architecture was introduced, where the server is a pow- erful computing unit and the web browser application is a client for user interface purposes. The challenge was to develop an application running under the...
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Functional Bi2O3/Gd2O3 Silica-Coated Structures for Improvement of Early Age and Radiation Shielding Performance of Cement Pastes
PublikacjaThis study presents a new approach towards the production of sol-gel silica-coated Bi2O3/Gd2O3 cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat Bi2O3/Gd2O3 structures and evaluated...
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Stripe order and magnetic anisotropy in the S=1 antiferromagnet BaMoP2O8
PublikacjaMagnetic behavior of yavapaiite-type BaMoP2O8 with the spatially anisotropic triangular arrangement of the S=1Mo4+ ions is explored using thermodynamic measurements, neutron diffraction, and density-functional band-structure calculations. A broad maximum in the magnetic susceptibility around 46 K is followed by the stripe antiferromagnetic order with the propagation vector k=(12,12,12) formed below TN≃21 K. This stripe phase is...
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(CsX)Cu5O2(PO4)2 (X = Cl, Br, I): A Family of Cu2+ S = 1/2 Compounds with Capped-Kagomé Networks Composed of OCu4 Units
PublikacjaThree new salt inclusion compounds (CsX)Cu5O2(PO4)2 (X = Cl, Br, I), phosphate analogues of the kagomé mineral averievite, are reported. Their crystal structures are composed of trigonal networks of corner-sharing OCu4 anion-centered tetrahedra, forming capped-kagomé planes, which can also be regarded as two-dimensional slices along the [111] direction of a pyrochlore lattice. Magnetization and heat capacity measurements reveal...
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Electric and magnetic properties of Lanthanum Barium Cobaltite
PublikacjaThe cubic Ba0.5La0.5CoO3‐δ was synthesized using solid state reaction. The structural properties were determined by the simultaneous refinement of Synchrotron Powder X‐ray Diffraction and Neutron Powder Diffraction data. Iodometric titration was used to examine the oxygen stoichiometry and average cobalt oxidation state. Low‐temperature magnetic studies show soft ferromagnetic character of fully oxidized material, with θP = 198(3)...
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Collision Strengths of Astrophysical Interest for Multiply Charged Ions
PublikacjaThe electron impact excitation and ionization processes are crucial for modeling the spectra of different astrophysical objects, from atmospheres of late-type stars to remnants of supernovae and up to the light emission from neutron star mergers, to name just a few. Despite their signifi- cance, however, little is known quantitatively about these processes for low- and medium-impact energies of, say, Ekin . 5000 eV of the free...
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Structure and water uptake in BaLnCo2O6−δ (Ln =La, Pr, Nd, Sm, Gd, Tb and Dy)
PublikacjaThe structure of BaLnCo2O6-δ (Ln =La, Pr, Nd, Sm, Gd, Tb and Dy) was studied by the means of synchrotron radiation powder X-ray diffraction, neutron powder diffraction and Transmission Electron Microscopy (TEM), while water uptake properties were analysed with the use of thermogravimetry (TG) and water adsorption isotherms. The structure refinement revealed that the dominant phase in all compositions was orthorhombic with an ordering...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublikacjaThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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New kagome prototype materials: discovery of KV3Sb5, RbV3Sb5, and CsV3Sb5
PublikacjaIn this work, we present our discovery and characterization of a new kagome prototype structure, KV3Sb5. We also present the discovery of the isostructural compounds RbV3Sb5 and CsV3Sb5. All materials exhibit a structurally perfect two-dimensional kagome net of vanadium. Density-functional theory calculations indicate that the materials are metallic, with the Fermi level in close proximity to several Dirac points. Powder and single-crystal...
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Potential Skyrmion Host Fe(IO3)3: Connecting Stereoactive Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction
PublikacjaMagnetic skyrmions, which are topologically distinct magnetic spin textures, are gaining increased attention for their unique physical properties and potential applications in spintronic devices. Here we present a design strategy for skyrmion host candidates based on combinations of magnetic spin, asymmetric building units having stereoactive lone-pair electrons, and polar lattice symmetry. To demonstrate the viability of the proposed...
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Spin and Orbital Effects on Asymmetric Exchange Interaction in Polar Magnets: M(IO3)2 (M = Cu and Mn)
PublikacjaMagnetic polar materials feature an astonishing range of physical properties, such as magnetoelectric coupling, chiral spin textures, and related new spin topology physics. This is primarily attributable to their lack of space inversion symmetry in conjunction with unpaired electrons, potentially facilitating an asymmetric Dzyaloshinskii–Moriya (DM) exchange interaction supported by spin–orbital and electron–lattice coupling. However,...
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Elemental composition, environment of deposition of the Lower Carboniferous Emma Fiord Formation oil shale in Arctic Canada
PublikacjaThe sedimentary succession of 51-m consisting of a thin coal seam (1 m) and oil shale with a marlstone and carbonate-mudstone matrix of the Lower Carboniferous (Viséan) Emma Fiord Formation located on the Grinnell Peninsula, Devon Island, Arctic Canada was examined. The techniques used include reflected light microscopy, and instrumental neutron activation analysis (INAA) for elemental concentration, and inductively coupled plasma...
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Porównanie OpenStack Networking z innymi rozwiązaniami chmurowymi
PublikacjaW dzisiejszych czasach coraz więcej firm decyduje się na uruchamianie usług oraz przetwarzanie danych w ramach tak zwanych systemów chmurowych, których przykładem może być m.in. OpenStack. Szeroka gama istniejących rozwiązań pozwala na dostosowanie chmury do potrzeb i wymagań użytkownika. Podczas wyboru systemu chmurowego jednym z ważniejszych aspektów jest analiza oferowanych przez niego mechanizmów oraz zaawansowanych usług sieciowych....
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Robert Piotrowski dr hab. inż.
OsobyRobert Piotrowski jest absolwentem Wydziału Elektrotechniki i Automatyki (2001r., kierunek: Automatyka i Robotyka) oraz Wydziału Zarządzania i Ekonomii (2002r., kierunek: Organizacja Systemów Produkcyjnych) Politechniki Gdańskiej. Od 2005 roku jest zatrudniony na Wydziale Elektrotechniki i Automatyki, aktualnie w Katedrze Inteligentnych Systemów Sterowania i Wspomagania Decyzji. W 2005 roku obronił rozprawę doktorską (Automatyka...