Three-dimensional (3-D) neutron transport benchmark problems proposed from Osaka University to NEACRP in 1988 have been calculated by many participants and the results summarized. The of k eff, control rod worth, region-averaged group fluxes for four core models various 3-D codes compared. There was consistency among results, when necessary corrections were made. solutions are quite useful as benchmarks checking validity codes.

Three-dimensional (3-D) neutron transport benchmark problems proposed from Osaka University to NEACRP in 1988 have been calculated by many participants and the results summarized. The of k eff, control rod worth, region-averaged group fluxes for four core models various 3-D codes compared. There was consistency among results, when necessary corrections were made. solutions are quite useful as benchmarks checking validity codes.

A d0 niobium(V) complex, NbCl3(α-diimine) (1a), supported by a dianionic redox-active N,N′-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1,3-butadiene (α-diimine) ligand (ene-diamido ligand) served as catalyst for radical addition reactions of CCl4 to α-olefins and cyclic alkenes, selectively affording 1:1 products in regioselective manner. During the catalytic reaction, α-diimine smoothly released stored an electron control oxidation state niobium center changing between η4-(σ2,π)...

A dibromobismuthine and a dibromostibine that bear 4-tBu-2,6-[CH(SiMe3)2]2-C6H2 (Tbb) groups were reduced with 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene to afford the corresponding stable dibismuthene (TbbBi═BiTbb) distibene (TbbSb═SbTbb), respectively. The only byproducts obtained easily removable tetramethylpyrazine bromotrimethylsilane. Importantly, inorganic salts not generated in this reduction: i.e., is unique inorganic-salt-free method for synthesis of...

A metal-free deoxygenation and reductive disilylation of nitroarenes was achieved using N,N'-bis(trimethylsilyl)-4,4'-bipyridinylidene (1) under mild neutral reaction conditions, a broad functional group tolerance possible in this reaction. Mono-deoxygenation, giving synthetically valuable N,O-bis(trimethylsilyl)phenylhydroxylamine (7 a) as readily available safe phenylnitrene source from nitrobenzene, double-deoxygenation, N,N-bis(trimethylsilyl)anilines 8, were easily controlled by varying...

Tungsten imido complexes bearing a redox-active ligand, such as N,N′-bis(2,6-diisopropylphenyl)-1,4-diaza-2,3-dimethyl-1,3-butadiene (L1), N,N′-bis(2,6-diisopropylphenyl)-1,4-diaza-1,3-butadiene (L2), and 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (L3), were prepared by salt-free reduction of W(═NC6H3-2,6-iPr2)Cl4 (1) using 1-methyl-3,6-bis(trimethylsilyl)-1,4-cyclohexadiene (MBTCD) followed addition the corresponding ligands. In initial stage, reaction with MBTCD afforded...

An adult man (A) entered a pit to collect seepage at an industrial waste site in Japan. As he suddenly lost consciousness, three colleagues (B, C, D) the rescue him. All of these men consciousness pit. Two workers (A and B) died soon after accident, one worker (C) 22 days (D) survived. Since hydrogen sulfide gas was detected atmosphere pit, poisoning suspected. Toxicological analyses thiosulfate, metabolite sulfide, blood urine victims were made using extractive alkylation technique combined...

Chromium-catalyzed cyclopropanation of alkenes with bromoform was achieved to produce the corresponding bromocyclopropanes.

A metathesis reaction of a WW bond and an NN was observed by reacting W–W triply-bonded W(<sc>iii</sc>)₂ complex, (^tBuO)₃WW(O^tBu)₃ (<bold>1</bold>), with benzo[<italic>c</italic>]cinnoline derivatives to form biphenyl-linked dinuclear (imido)tungsten complexes <bold>2–4</bold>.

A tungsten alkylidyne complex [{(OC6H2tBu2-4,6)2(SCH2CH2S)}W(≡CEt)X] (X = OtBu, 1a) with a bridged bis(phenolate) ligand was prepared from the alkoxy precursor (tBuO)3W≡CEt and corresponding bis(phenol). The tert-butoxy in 1a substituted against chloride or trimethylsilylmethyl to give 1b Cl) 1c CH2SiMe3). X-ray diffraction studies of showed an octahedral cis α-configuration metal atom. Hydride abstraction β-position n-propylidyne [Ph3C][B(C6F5)4] gave high-valent cationic vinylidene...

Abstract A new nodal transport method has been developed so as to perform accurate calculations in three-dimensional (3-D) hexagonal geometry. In the present neutron angular distributions of intra-node fluxes and transverse-leakage are represented using SN quadrature set, spatial distribution source is approximated by a quadratic polynomial expansion. Additionally, authors have applied nodal-equivalent finite difference algorithm 3-D geometry order establish stable efficient iterative...

A new nodal transport method has been developed so as to perform accurate calculations in three-dimensional (3-D) hexagonal geometry. In the present neutron angular distributions of intra-node fluxes and transverse-leakage are represented using SN quadrature set, spatial distribution source is approximated by a quadratic polynomial expansion. Additionally, authors have applied nodal-equivalent finite difference algorithm 3-D geometry order establish stable efficient iterative scheme. The...

The present paper reviews activates relevant to the boiling water reactor (BWR) stability phenomenon, which has a coupled neutronic and thermal-hydraulic nature, from viewpoint of model code developments their applications BWR solution methodology in Japan.

A space/time nodal diffusion code based on the expansion method (NEM), EPISODE, was developed in order to evaluate transient neutron behavior light water reactor cores. The present employs improved quasi-static (IQS) for spatial kinetics, and flux distribution is numerically obtained by solving equation with nonlinear iteration scheme achieve fast computation. predictor-corrector (PC) study enabled apply a coarse time mesh calculation than that applicable conventional IQS model, which...

Abstract A simple experimental model for a fundamental investigation of creep groan generating mechanism is introduced. It calliper slider that developed based on the operating principle real brake system and has ability to generate quantitatively comparable those recorded system. The advantage it possible take into account many parameters, such as surface roughness mating materials, properties materials structure's stiffness, so their effects phenomenon can be analysed. usefulness potential...

The Cβ–Cβ bond fission of a tantallacyclopentadiene moiety bridged over low-valent Ta(V)–Ta(III) dinuclear tantalum complex 2, having an infinite structure, was facilitated by the coordination 1,10-phenanthroline (PHEN) to give doubly η2-alkyne-bridged ditantalum (phen)Cl2Ta(μ,η2-C2Et2)2TaCl2(phen) (8), while corresponding high oxidation Ta(V)–Ta(V) complex, Cl2Ta(μ,η4-C4Et4)(μ-Cl)TaCl3 (1), afforded Cl3Ta(μ,η4-C4Et4)(μ-Cl)TaCl2(phen) (7) with intact metallacyclopentadiene structure....