On the temperature dependence of the rate coefficient of formation of C2+ from C + CH+

[EN] We carry out quasi-classical trajectory caculations for theC + CH+ ��� C2+ + H reaction on an ad hoc computed high-level ab initio potential energy surface. Thermal rate coefficients at the temperatures of relevance in cold interstellar clouds are derived and compared with the assumed, temperature-independent estimates publicly available in kinetic databases KIDA and UDfA. For a temperature of 10 K the database value overestimates by a factor of two the one obtained by us (thus improperly enhancing the destruction route of CH+ in astrochemical kinetic models) which is seen to double in the temperature range 5���300 K with a sharp increase in the first 50 K. The computed values are fitted via the popular Arrhenius���Kooij formula and best-fitting parameters �� = 1:32 X 10-9 cm3s-1, �� = 0:10 and �� = 2:19 K to be included in the online mentioned databases are provided. Further investigation shows that the temperature dependence of the thermal rate coefficient better conforms to the recently proposed so-called ���deformed Arrhenius��� law by Aquilanti and Mundim.

Role of G protein coupled inwardly rectifier K+ channels (GIRK) on the neurobiology depression

353 p��gs.

The long road of climate negotiations: From Kyoto to Paris stopping over in Doha

4 p.

Stability analysis of RF amplifiers based on MIMO pole-zero identification

Spurious oscillations are one of the principal issues faced by microwave and RF circuit designers. The rigorous detection of instabilities or the characterization of measured spurious oscillations is still an ongoing challenge. This project aims to create a new stability analysis CAD program that tackles this chal- lenge. Multiple Input Multiple Output (MIMO) pole-zero identi���cation analysis is introduced on the program as a way to create new methods to automate the stability analysis process and to help designers comprehend the obtained results and prevent incorrect interpretations. The MIMO nature of the analysis contributes to eliminate possible controllability and observability losses and helps differentiate mathematical and physical quasi-cancellations, products of overmodeling. The created program reads Single Input Single Output (SISO) or MIMO frequency response data, and determines the corresponding continuous transfer functions with Vector Fitting. Once the transfer function is calculated, the corresponding pole/zero diagram is mapped enabling the designers to analyze the stability of an ampli���er. Three data processing methods are introduced, two of which consist of pole/zero elimina- tions and the latter one on determining the critical nodes of an ampli���er. The ���rst pole/zero elimination method is based on eliminating non resonant poles, whilst the second method eliminates the poles with small residue by assuming that their effect on the dynamics of a system is small or non-existent. The critical node detection is also based on the residues; the node at which the effect of a pole on the dynamics is highest is de���ned as the critical node. In order to evaluate and check the ef���ciency of the created program, it is compared via examples with another existing commercial stability analysis tool (STAN tool). In this report, the newly created tool is proved to be as rigorous as STAN for detecting instabilities. Additionally, it is determined that the MIMO analysis is a very pro���table addition to stability analysis, since it helps to eliminate possible problems of loss of controllability, observability and overmodeling.