A gauge to demonstrate low gas pressures to large classes

1974 ◽  
Vol 3 (1) ◽  
pp. 105-106
Author(s):  
S. W. Ehler
Keyword(s):  
Large Classes ◽  
Gas Pressures

Principles of Low-Vacuum SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1304-1305
Author(s):  
Klaus-Ruediger Peters
Keyword(s):  
New Technologies ◽  
High Vacuum ◽  
Optical Microscope ◽  
Specimen Surface ◽  
Electrical Field ◽  
Gaseous Environment ◽  
New Information ◽  
Gas Molecules ◽  
New Interactions ◽  
Gas Pressures

Only recently it became possible to expand scanning electron microscopy to low vacuum and atmospheric pressure through the introduction of several new technologies. In principle, only the specimen is provided with a controlled gaseous environment while the optical microscope column is kept at high vacuum. In the specimen chamber, the gas can generate new interactions with i) the probe electrons, ii) the specimen surface, and iii) the specimen-specific signal electrons. The results of these interactions yield new information about specimen surfaces not accessible to conventional high vacuum SEM. Several microscope types are available differing from each other by the maximum available gas pressure and the types of signals which can be used for investigation of specimen properties.Electrical non-conductors can be easily imaged despite charge accumulations at and beneath their surface. At high gas pressures between 10-2 and 2 torr, gas molecules are ionized in the electrical field between the specimen surface and the surrounding microscope parts through signal electrons and, to a certain extent, probe electrons. The gas provides a stable ion flux for a surface charge equalization if sufficient gas ions are provided.

Modifikasi Sistem Asistensi dan Responsi Kelas Kecil pada Praktikum Parasitologi Blok Digestif dan Hematoimunologi Fakultas Kedokteran Universitas Riau

2017 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Suri Dwi Lesmana ◽  
Esy Maryanti
Keyword(s):  
Large Class ◽  
Teaching And Learning ◽  
Learning Activities ◽  
Small Class ◽  
Laboratory Practice ◽  
Large Classes ◽  
Average Value ◽  
Competency Based

Faculty of Medicine University of Riau has been implementing Competency Based Curriculum (KBK) with theProblem Based Learning (PBL) since 2007 with the implementation of teaching and learning activities of the systemconsists of a tutorial activities, skillab, expert lectures, independent and practical. However, there are still manyproblems in the implementation of the KBK on preclinic degree. One part of the block that is identified to be one ofthe causes of low graduation exam block is less efective coaching laboratory practice. Parasitology is one part of thetask is to provide laboratory practice in several blocks on the stage of preclinic especially digestive and hematoimunologyblock. This study aimed to compare the results of the evaluation of parasitology laboratory practice in hematoimunologyand digestive assistance and posttest in large classes with small class. Assistance and posttest in large class performedon the digestive block implementation and hematoimunologi in 2011 while assisting and posttest of small classes ona block implementation in 2012. Average value of small class digestive laboratory practice was not significantlylower than the large class but the proportion of the value of quality B and C more many in small classes. The meanvalue of the block hematoimunologi laboratory practice significantly higher on small class assistance and posttest aswell as the proportion of the value of quality A, B and C was higher in small classes than large classes.

Detection and representation of the basic peculiarities of vegetation cover by the mapping method (experience based on a research of goltsy-taiga territories)

2013 ◽  
pp. 32-47
Author(s):  
S. V. Osipov
Keyword(s):  
Vegetation Cover ◽  
Mapping Method ◽  
Vegetation Changes ◽  
Large Classes ◽  
High Rise ◽  
The Third ◽  
Altitudinal Belts ◽  
The One ◽  
Dynamic Series ◽  
River Valleys

Geobotanical mapping of the territory in riverheads Bureya of 4500 sq.km is carried out and the map of a actual vegetation cover of scale 1 : 200 000 is prepared. The legend of the map is presented in the form of the text with three-level hierarchy of classes. At the heart of structure of a legend of the map such regularities of a vegetation cover, as its latitudinal zonality / altitudinal belts, situation in a relief and dynamic series lie. The largest divisions of the legend reflect, first, change of large classes of mesocombinations of vegetation at the level of belts and, secondly, distinction in a boreal - forestry belt between a vegetation cover of tops and slopes of mountains, on the one hand, and the bottoms of river valleys, with another. Divisions of the legend of the second level reflect, first, vegetation changes in the form of high-rise and barrier changes of subbelts, secondly, distinctions of a vegetation cover in different geomorphological conditions (small and average river valleys, northern slopes, etc.). Divisions of the legend of the second level correspond to dynamic series of units of the third level. Essential addition to it are block diagrams of dynamics of a vegetation cover.

Teaching English in Large Classes

2010 ◽  
Vol 5 (2) ◽  
Author(s):  
Madhu Upadhaya
Keyword(s):  
Teaching English ◽  
Large Classes
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