Analytical Calculation of Coupled Magnetothermal Problem in Gas Insulated Transmission Lines

Gas insulated transmission lines (GIL) are a new technology for transmitting power over long distances. In this paper, an analytical method (AM) is proposed to investigate the coupled magnetothermal problem in GIL. Kelvin functions are employed to calculate the skin effect coefficients of the conductor and the enclosure. The calculated power losses are used as heat source input for the thermal analysis. Considering the convective and radiation heat transfer effects, the heat balance equations on the surface of the conductor and the enclosure are established, respectively. Temperature rise of the GIL at different operation conditions are investigated. The proposed method is validated against the finite element method (FEM). The simplicity of the approach makes it attractive for self-made software implementation in the thermal design and the condition monitoring of GIL

Location of modulatory β subunits in BK potassium channels

Large-conductance voltage- and calcium-activated potassium (BK) channels contain four pore-forming α subunits and four modulatory β subunits. From the extents of disulfide cross-linking in channels on the cell surface between cysteine (Cys) substituted for residues in the first turns in the membrane of the S0 transmembrane (TM) helix, unique to BK α, and of the voltage-sensing domain TM helices S1–S4, we infer that S0 is next to S3 and S4, but not to S1 and S2. Furthermore, of the two β1 TM helices, TM2 is next to S0, and TM1 is next to TM2. Coexpression of α with two substituted Cys’s, one in S0 and one in S2, and β1 also with two substituted Cys’s, one in TM1 and one in TM2, resulted in two αs cross-linked by one β. Thus, each β lies between and can interact with the voltage-sensing domains of two adjacent α subunits

Group 13 metal(I) and (II) guanidinate complexes: effect of ligand backbone on metal oxidation state and coordination sphere

Reactions of lithium salts of the bulky guanidinate and phosphaguanidinate ligands, [ArNC(ER2)NAr]− (ER2 = NPri2 (Priso−), cis-NC5H8Me2-2,6 (Pipiso−) or P(C6H11)2 (PGiso−); Ar = C6H3Pri2-2,6), with group 13 metal(I) halides have been carried out. All reactions with TlBr led to monomeric thallium(I) complexes, [Tl{ArNC(ER2)NAr}], in which the ligand chelates the metal in an N,arene-fashion. The reactions with InCl led to mixed results and the isolation of the dimeric indium(II) complexes, [{InCl(Priso)}2] and [{InCl(Pipiso)}2], and the monomeric indium(I) species, [In(Pipiso)] and [In(PGiso)]. The ligands of the latter two complexes exhibit differing coordination modes in the solid state, namely N,N'-chelating and N,arene-chelating, respectively. The reactions with "GaI" were less successful and gave only low yields of the poorly characterised gallium(II) complexes, [{GaI(Priso)}2] and [{GaI(Pipiso)}2]. This study has shown that the related ligand, [ArNC{N(C6H11)2}NAr]− (Giso−) is superior for the stabilisation of group 13 metal(I) complexes. The oxidative additions of I2 or SiMe3I to one such complex, [Ga(Giso)], yielded the gallium(III) compounds, [GaI2(Giso)] and [GaI(SiMe3)(Giso)]

Synthesis and characterisation of bulky guanidines and phosphaguanidines: precursors for low oxidation state metallacycles

Reactions of alkali metal amides or phosphides with the bulky carbodiimide, ArN[double bond, length as m-dash]C[double bond, length as m-dash]NAr (Ar = C6H3Pri2-2,6), followed by aqueous work-ups, have yielded several guanidines, ArNC(NR2)N(H)Ar (R = cyclohexyl (GisoH) or Pri (PrisoH); NR2 = cis-NC5H8Me2-2,6 (PipisoH)), a bifunctional guanidine, {ArNCN(H)Ar}2{µ-N(C2H4)2N} (Pip(GisoH)2), and two phosphaguanidines, ArNC(PR2)N(H)Ar (R = cyclohexyl (CyP-GisoH) or Ph (PhP-GisoH)). A very bulky guanidine, ArNC{N(Ar)SiMe3}N(H)Ar (ArSi-Giso), and an aryl coupled bifunctional guanidine, {ArN(H)C(NPri2)NC6H2Pri2-2,6-}2 (PrisoH)2, have been prepared by other routes. All compounds have been crystallographically characterised and shown to exist in a number of isomeric forms in the solid state. These appear to be largely retained in solution. The deprotonation of GisoH with BunLi in either hexane or THF led to crystallographically characterised dimeric and monomeric complexes respectively, viz. [Li{Li(κ2-N,N'-Giso)2}] and [Li(THF)(η1-N,η3-Ar-Giso)]. Deprotonation of PrisoH and Pip(GisoH)2 with K[N(SiMe3)2] gave the unsolvated polymer, [{K(η1-N,η6-Ar-Priso)}∞], and the solvated complex, [{K(THF)2}{Pip(Giso)2}{K(THF)3}], respectively

CCDC 627835: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 627833: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures