UK PubMed Central (United Kingdom)

In higher plants, three subfamilies of sucrose nonfermenting-1 (Snf1)-related protein kinases have evolved. While the Snf1-related protein kinase 1 (SnRK1) subfamily has been shown to share pivotal...Full Text Available

International Nuclear Information System (INIS)

In this paper the authors present a design study on the longitudinal dynamics of a relativistic klystron two-beam accelerator (RK-TBA) scheme which has been proposed as a power source candidate for a 1 TeV next linear collider (NLC). They address the issue of maintaining stable power output at desired level for a 300-m long TBA with 150 extraction cavities and present their simulation results to demonstrate that it can be achieved by inductively detuning the extraction cavities to counter the space charge debunching effect on the drive beam. They then carry out simulation study to show that the beam bunches desired by the RK-TBA can be efficiently obtained by first chopping an initially uniform beam of low energy into a train of beam bunches with modest longitudinal dimension and then using the open-quotes adiabatic captureclose quotes scheme to bunch and accelerate these beam bunches into tight bunches at the operating energy of the drive ...

Science.gov (United States)

In this project the influence of residual compression stresses on the stress corrosion cracking behaviour of the turbine disc steel 26 NiCrMoV 14 5 (Rp(sub 0.2) = 850 N/mm(sup 2)) was investigated. The residual compression stresses were produced by shot p...

International Nuclear Information System (INIS)

A new evaluation of the 1% time strain limit for creep strength and the isochronous stress/strain relationship was to be undertaken for the type 800 alloy, based on up to date experimental data. After the evaluation of the 1% time strain limit curves and time fracture curves of individual melts, multilinear regression analyses were made to clear up the relationship between parameters of the creep behaviour such as creep strength, 1% time strain limit and time fracture strain on the one hand and metallurgical parameters such as C, Ti, Al, Ni, Cr contents or grain size and type of manufacture, on the other hand. Based on the knowledge gained from these calculations, new limits were determined for HTR material specifications for variants of the 800 alloy of the Rk, NT, DE, and HT type. (orig./DG).

International Nuclear Information System (INIS)

In an HTR plant high temperature components of Alloy 800 materials are subjected to temperatures from about 550 to 850degC in the long term; higher temperatures may occur in the short term. Thus the creep and stress-rupture parameters govern the design of these components. Since in recent years the scope of experimental data available for Alloy 800 materials has considerably increased, a new evaluation of the creep and creep-rupture properties was performed using a data bank computer. The relationships between the characteristics of the creep and creep-rupture behaviour and the metallurgical parameters were investigated by multilinear regression analyses. On the basis of the results of these analyses and after discussion in material expert committees new material specifications were determined for different types of Alloy 800. They were included into the draft standards DIN 17459 and DIN 17460 under the material standard nos. 1.4958, 1.4958 Rk and 1.4959. Besides ...

International Nuclear Information System (INIS)

For the positive self-adjoint operators H = -#partial deriv#_i_g_i_j(x)#partial deriv# + q(x) on H triple-bond L"2(R"n) with n #>=# 3, it is shown that parallel(|x|)"-"1(#sq root#H - z)"-"1(|x| + 1)"-"1 parallel ##0"+, by imposing several conditions on g_i_j and q. In the special case g_i_j = c"2#delta#_i_j these conditions reduce to |x|#centre dot##nabla#c, (x"2 + 1)"1"+"v"a"r"-"e"p"s"i"l"o"n(|q(x)| + |x#centre dot##nabla#q|) #epsilon# L"#infinity# with the nontrapping condition (c - x#centre dot# #DELTA#c) #>=# kc, and a positivity condition C(x"2 + 1)"-"1 # 0. Results are applied to the stratified wave equation (#partial deriv#_t"2 - c"2(y)#DELTA#_z)#psi# = 0, where z = x circle-plus y #epsilon# R"k circle-plus R"m with n = k + m, and |y|(y#centre dot##nabla#_yc)#epsilon# L"#infinity#(R"m). In all cases the condition (c-y#centre dot##nabla#_yc) #<=# kc leads to a local-energy decay estimate for #psi#(z,1). 11 refs.

Energy Technology Data Exchange (ETDEWEB)

For the step-and-shoot intensity-modulated radiation therapy (IMRT) technique, the combination of high dose rate, multiple beam segments and low dose per segment can lead to significant differences between the planned dose and the dose delivered to the patient. In this technique, a dose delivery inaccuracy known as the 'overshoot' effect is caused by the dose servo control system. This typically occurs in the first and last beam segments and causes an over- and underdose, respectively. Some dose positional error in the segment sequence is also possible there. Commercial ionization chambers (RK-type) and radiographic Kodak films were used for the measurements. The reported results were obtained using the Pinnacle{sup 3}-V6.2 treatment planning system and a Varian Clinac 21 EX linear accelerator equipped with a 120-leaf Millennium MLC. The dose inaccuracy measurements were based on the comparison of the dose and profiles for reference fields and ...