929 resultados para Nuclear weapons


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This is volume II of my two-volume study of the nuclear strategies/strategy preferences of Britain, France and West Germany in the Cold War. It shows that the great variable is the mentalities, culture, and particular interpretations of particular historical experiences of these three countries. These mental frameworks are reconstructed, in the tradition of the French Annales/Mentalite schools (that in turn is rooted in anthropology) by looking at a very large nunber of public texts in the context of the public discourse about nuclear strategy in each country.

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This is vol. I of my two-volume study of the nuclear strategies/strategy preferences of NATO collectively, and individually of Britain, France, and West Germany in the Cold War. It shows that NATO strategy was a fragile compromise, and that these three countries, all within range of Soviet medium/intermediate range nuclear missiles and thus with less geostrategic difference than in previous military threat contexts, had wildly divergent strategies/preferences which cannot be explained merely by geography. It raises the question of what made them so different, addressed in Volume II "Nuclear Mentalities" (q.v.)

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Given the danger of the unbearable catastrophe of nuclear war, NATO in the mid-1950s abandoned any war aim of achieving victory in an all-out war with the Soviet Union or the Warsaw Treaty Organisation. Instead, it adopted the war aim of a cease-fire or war termination. By contrast, the WTO clung on to the war aim of victory - expressed even in terms of the survival of slightly more Soviet citizens than NATO citizens, after unprecedented losses of life in nuclear exchanges - until the mid-1980s when under Gorbachev the concept of victory in nuclear war was abandoned.

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Archive-based study of the dependence of NATO member states on the USA as nuclear guarantor, and the problems this entailed.

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European writers on strategy (in French: strategistes, as opposed to practitioners, stratèges) developed their thoughts on the best strategies and postures of nuclear deterrence against their own beliefs in the identities of their own countries - were they seen as "Europesn" or as "nation-states" who must under no condition surrender their sovereignty?

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If Britain wants to stem the tide of nuclear proliferation, it must continue to assume "the nuclear man's burden" and guarantee the security of non-nuclear allies, as it did in the Cold War.

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A mononuclear octahedral nickel(II) complex [Ni(HL(1))(2)](SCN)(2) (1) and an unusual penta-nuclear complex [{(NiL(2))(mu-SCN)}(4)Ni(NCS)(2)]center dot 2CH(3)CN (2) where HL(1) = 3-(2-aminoethylimino)butan-2-one oxime and HL(2) = 3-(hydroxyimino)butan-2-ylidene)amino)propylimino)butan-2-one oxime have been prepared and characterized by X-ray crystallography. The mono-condensed ligand, HL(1), was prepared by the 1:1 condensation of the 1,2-diaminoethane with diacetylmonoxime in methanol under high dilution. Complex 1 is found to be a mer isomer and the amine hydrogen atoms are involved in extensive hydrogen bonding with the thiocyanate anions. The dicondensed ligand, HL(2), was prepared by the 1:2 condensation of the 1,3-diaminopropane with diacetylmonoxime in methanol. The central nickel(II) in 2 is coordinated by six nitrogen atoms of six thiocyanate groups, four of which utilize their sulphur atoms to connect four NiL2 moieties to form a penta-nuclear complex and it is unique in the sense that this is the first thiocyanato bridged penta-nuclear nickel(II) compound with Schiff base ligands.

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The nuclear time-dependent Hartree-Fock model formulated in three-dimensional space, based on the full standard Skyrme energy density functional complemented with the tensor force, is presented. Full self-consistency is achieved by the model. The application to the isovector giant dipole resonance is discussed in the linear limit, ranging from spherical nuclei (16O and 120Sn) to systems displaying axial or triaxial deformation (24Mg, 28Si, 178Os, 190W and 238U). Particular attention is paid to the spin-dependent terms from the central sector of the functional, recently included together with the tensor. They turn out to be capable of producing a qualitative change on the strength distribution in this channel. The effect on the deformation properties is also discussed. The quantitative effects on the linear response are small and, overall, the giant dipole energy remains unaffected. Calculations are compared to predictions from the (quasi)-particle random-phase approximation and experimental data where available, finding good agreement

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The role of the tensor terms in the Skyrme interaction is studied for their effect in dynamic calculations where non-zero contributions to the mean-field may arise, even when the starting nucleus, or nuclei are even-even and have no active time-odd potentials in the ground state. We study collisions in the test-bed 16O-16O system, and give a qualitative analysis of the behaviour of the time-odd tensor-kinetic density, which only appears in the mean field Hamiltonian in the presence of the tensor force. We find an axial excitation of this density is induced by a collision.

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Bis-triazinylphenanthroline ligands (BTPhens), which contain additional alkyl (n-butyl and sec-butyl) groups attached to the triazine rings, have been synthesized, and the effects of this alkyl substitution on their extraction properties with Ln(III) and An(III) cations in simulated nuclear waste solutions have been studied. The speciation of n-butyl-substituted ligand (C4- BTPhen) with some trivalent lanthanide nitrates was elucidated by 1 H-NMR spectroscopic titrations. These experiments have shown that the dominant species in solution were the 1:2 complexes [Ln(III)(BTPhen)2], even at higher Ln(III) concentrations, and the relative stability of 2:1 to 1:1 BTPhen-Ln(III) complexes varied with different lanthanides. As expected, sec-butylsubstituted ligand (sec-C4 BTPhen) showed higher solubility than C4-BTPhen in certain diluents. A greater separation factor (SFAm/Eu = ca. 210) was observed for sec-C4-BTPhen compared to C4-BTPhen (SFAm/Eu = ca. 125) in 1-octanol at 4 M HNO3 solutions. The greater separation factor may be due to the higher solubility of the 2:1 complex for sec-C4-BTPhen at the interface than the 1:1 complex of C4-BTPhen.

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The approach of reaggregation involves the regeneration and self-renewal of histotypical 3D spheres from isolated tissue kept in suspension culture. Reaggregated spheres can be used as tumour, genetic, biohybrid and neurosphere models. In addition the functional superiority of 3D aggregates over conventional 2D cultures developed the use of neurospheres for brain engineering of CNS diseases. Thus 3D aggregate cultures created enormous interest in mechanisms that regulate the formation of multicellular aggregates in vitro. Here we analyzed mechanisms guiding the development of 3D neurosphere cultures. Adult neural stem cells can be cultured as self-adherent clusters, called neurospheres. Neurospheres are characterised as heterogeneous clusters containing unequal stem cell sub-types. Tumour necrosis factor-alpha (TNF-alpha is one of the crucial inflammatory cytokines with multiple actions on several cell types. TNF-alpha strongly activates the canonical Nuclear Factor Kappa-B (NF- kappaB) pathway. In order to investigate further functions of TNF in neural stem cells (NSCs) we tested the hypothesis that TNF is able to modulate the motility and/or migratory behaviour of SVZ derived adult neural stem cells. We observed a significantly faster sphere formation in TNF treated cultures than in untreated controls. The very fast aggregation of isolated NSCs (<2h) is a commonly observed phenomenon, though the mechanisms of 3D neurosphere formation remain largely unclear. Here we demonstrate for the first time, increased aggregation and enhanced motility of isolated NSCs in response to the TNF-stimulus. Moreover, this phenomenon is largely dependent on activated transcription factor NF-kappaB. Both, the pharmacological blockade of NF-kappaB pathway by pyrrolidine dithiocarbamate (PDTC) or Bay11-7082 and genetic blockade by expression of a transdominant-negative super-repressor IkappaB-AA1 led to decreased aggregation.

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Natural plant-derived products are commonly applied to treat a broad range of human diseases, including cancer as well as chronic and acute airway inflammation. In this regard, the monoterpene oxide 1,8-cineol, the active ingredient of the clinically approved drug Soledum®, is well-established for the therapy of airway diseases, such as chronic sinusitis and bronchitis, chronic obstructive pulmonary disease and bronchial asthma. Although clinical trials underline the beneficial effects of 1,8-cineol in treating inflammatory diseases, the molecular mode of action still remains unclear. Here, we demonstrate for the first time a 1,8-cineol-depending reduction of NF-κB-activity in human cell lines U373 and HeLa upon stimulation using lipopolysaccharides (LPS). Immunocytochemistry further revealed a reduced nuclear translocation of NF-κB p65, while qPCR and western blot analyses showed strongly attenuated expression of NF-κB target genes. Treatment with 1,8-cineol further led to increased protein levels of IκBα in an IKK-independent matter, while FRET-analyses showed restoring of LPS-associated loss of interaction between NF-κB p65 and IκBα. We likewise observed reduced amounts of phosphorylated c-Jun N-terminal kinase 1/2 protein in U373 cells after exposure to 1,8-cineol. In addition, 1,8-cineol led to decreased amount of nuclear NF-κB p65 and reduction of its target gene IκBα at protein level in human peripheral blood mononuclear cells. Our findings suggest a novel mode of action of 1,8-cineol through inhibition of nuclear NF-κB p65 translocation via IκBα resulting in decreased levels of proinflammatory NF-κB target genes and may therefore broaden the field of clinical application of this natural drug for treating inflammatory diseases.

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This chapter brings a human security lens to bear on the energy-mix question in post-Fukushima Japan. In particular, two of the four elements of human security identified in the 1994 Human Development Report (HDR), prevention and people-centeredness, are mobilized. We trace developments in Japan’s post-Fukushima nuclear politics through the demise of DPJ rule to the advent of the LDP government, and evaluate the current nuclear energy strategy of the Abe administration. Using a human security framework, we consider the economic security dimension of the arguments for and against the use of nuclear power, and weigh the result of this consideration against a concern with the six other elements of human security identified in the 1994 HDR. We conclude that the risks and threats to human security engendered by the use of nuclear energy outweigh any benefits that could reasonably be argued to accrue from its use. The notion of prevention, so central to the concept of human security, performs a further ‘trumping’ function, in leading us to put a premium on the downside risk of the use of nuclear energy.

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In analysis of complex nuclear forensic samples containing lanthanides, actinides and matrix elements, rapid selective extraction of Am/Cm for quantification is challenging, in particular due the difficult separation of Am/Cm from lanthanides. Here we present a separation process for Am/Cm(III) which is achieved using a combination of AG1-X8 chromatography followed by Am/Cm extraction with a triazine ligand. The ligands tested in our process were CyMe4-BTPhen, CyMe4- BTBP, CA-BTP and CA-BTPhen. Our process allows for purification and quantification of Am and Cm (recoveries 80%–100%) and other major actinides in < 2d without the use of multiple columns or thiocyanate. The process is unaffected by high level Ca(II)/Fe(III)/Al(III) (10mg mL−1) and thus requires little pre-treatment of samples.