Differential pumping requirements for the light-ion helicon source and heating systems of Proto-MPEX

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Download Full-text

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062324 ◽

1969 ◽

Vol 27 ◽

pp. 82-83

Author(s):

Chester J. Calbick ◽

Richard E. Hartman

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

Local Environment ◽

Chamber Pressure ◽

Objective Lens ◽

Ion Pump ◽

Quantitative Studies ◽

Precise Knowledge ◽

Differential Pumping ◽

And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

Download Full-text

Innovative electrotechnological systems to provide the temperature modes of technological pipelines

Power and Autonomous equipment ◽

10.32464/2618-8716-2019-2-1-29-39 ◽

2019 ◽

Vol 2 (1) ◽

pp. 29-39 ◽

Cited By ~ 1

Author(s):

S. G. Konesev ◽

P. A. Khlyupin

Keyword(s):

Induction Heating ◽

Thermal Exposure ◽

Heating System ◽

The Arctic ◽

Process Conditions ◽

Heating Systems ◽

Fluid Properties ◽

Low Efficiency ◽

Extreme North ◽

Induction Heating System

Introduction: the systems of thermal effects on thermo-dependent, viscous and highly viscous liquids under conditions of the Arctic and the Extreme North are considered. Low efficiency and danger of heating systems based on burned hydrocarbons, heated liquids and steam are shown. Electrothermal heating systems used to maintain thermo-dependent fluids in a fluid state are considered. The evaluation of the effectiveness of the application of the most common electrothermal system — heating cables (tapes). The most effective electrothermal system based on induction technologies has been determined. Materials and methods: considered methods of thermal exposure to maintain the fluid properties of thermo-dependent fluids at low extreme temperatures. Results: presents an induction heating system and options for its implementation in the Extreme North and the Arctic. Conclusions: induction heating system to minimize loss of product quality, improve the system performance under changing process conditions, eliminate fire product, to reduce the influence of the human factor.

Download Full-text

CONCEPTUAL POSITIONS OF MODERNIZATION OF EXISTING INEFFICIENT DISTRICT HEATING SYSTEMS

Energy Technologies & Resource Saving ◽

10.33070/etars.2.2017.02 ◽

2017 ◽

pp. 11-21

Author(s):

Ye.Ye. Nikitin

Keyword(s):

Energy Efficient ◽

Mutual Influence ◽

District Heating ◽

Current Status ◽

Cognitive Approach ◽

Heating Systems ◽

Energy Management Systems ◽

Current State ◽

Self Sufficiency ◽

District Heating Systems

The current situation in the sphere of district heating is analysed on the basis of use of the cognitive approach. The presence of closed chains of cause-effect relationships of negative factors and conflicts of target settings of the subjects in the field of district heating is shown. The conceptual model of energy efficient modernization of district heating systems is proposed. This model includes indicators of the current status of heat sources, networks and heat consumers, energetic and economic models, restrictions, procedure of forming and analysis of the mutual influence of the recommended projects. The quantitative data on indicators of the current state of district heating systems of the cities of Ukraine are presented. The interrelation between indicators of the current state and projects of energy efficient modernization of district heating systems is shown. Assessment of energy self-sufficiency of municipal district heating systems on condition of thermal modernization of buildings is carried out. The creation of energy management systems at the district heating enterprises is proposed. Bib. 6, Fig. 7, Tab. 5.

Download Full-text