Development of a portable electroanalytical system for the stripping voltammetry of metals: Determination of copper in acetic acid soil extracts

The development, characterisation and evaluation of a prototype portable electrochemical trace metal analyser are presented. The instrument is a battery-powered microcontroller-based potentiostat, which implements anodic stripping voltammetry (ASV) at suitable sensor electrodes. It is capable of operating away from the laboratory, in the absence of an external power source and is usable by low-skilled personnel. The distinguishing feature of the instrument is its custom software, which enables sample pre-screening, data processing and sample dilution and standard additions calculations to be carried out. The instrument has been evaluated by application of a methodology for the detection of copper in acetic acid soil extracts, both in the laboratory and in the field. Underpotential deposition staircase anodic stripping voltammetry (UPD-SCASV) of the copper at gold disk electrodes was used as a test method. There was good agreement between the instrument results and those from laboratory-based reference analytical methods for analyses carried out both in the laboratory and in the field

IR Spectroscopy as a Method for Investigation of the Structure of Succinimide Type Additives Activity

В исследовании методом инфракрасной спектроскопии изучены синтезированные сукцинимидные присадки, а также сырьевые и промежуточные компоненты: полиизобутилен, малеиновый ангидрид, полиэтиленполиамны и алкенилянтарный ангидрид. На основании результатов выявлены зависимости диспергирующей способности и ИК-спектров присадок. Намечены пути дальнейших исследований по теме

Possibilities of increase of gyrotron efficiency via frequency locking by external signal

Possibility of efficiency increase of a gyrotron, which frequency is locked by an external monochromatic signal, is studied. Dependencies of orbital efficiency on cyclotron frequency resonance mismatch for different currents of the electron beam are found. It is shown that in multi-mode gyrotron there is a possibility of shifting of frequency-locking zone to the region of parameters corresponding to the optimal efficiency, so efficiency may be significantly increased compared to the free gyrotron