BACTERIA CAN PENETRATE ROCK

1966 ◽  
Vol 12 (3) ◽  
pp. 477-484 ◽  
Author(s):  
G. E. Myers ◽  
R. G. L. McCready
Keyword(s):  
Atmospheric Pressure ◽  
Radioactive Phosphorus ◽  
Early Devonian ◽  
Late Mesozoic ◽  
The Core ◽  
Demineralized Water ◽  
Test Microorganism ◽  
Rock Cores ◽  
Mississippian Limestone ◽  
And Migration

A method is described for studying the penetration of bacteria in intact rock cores. The test microorganism (Serratia marcescens ATCC No. 274) was labelled with radioactive phosphorus (32P) and suspended in sterile demineralized water. The cell suspension was allowed to enter the epoxy-coated rock core under atmospheric pressure. Penetration and migration of the labelled microorganisms were followed by measuring the radiation emitted at ports drilled through the epoxy coating, at various locations throughout the length of the core, and at various intervals of time after the beginning of the experiment. When migration was considered to be complete the core was aseptically split longitudinally and the results of the radiation studies confirmed by autoradiogram and culture. S. marcescens passed through 14.25 in. of Berea sandstone (the longest core available), and through 3-in. cores (longest available) of Mississippian limestone, Early Devonian limestone, and Late Mesozoic sandstone. The significance of these findings is discussed with respect to presence of so-called prehistoric microorganisms in geological specimens.

Conclusion

2007 ◽  
Author(s):  
Michael B. Miller
Keyword(s):  
Immigration Policy ◽  
Migration Patterns ◽  
The Core ◽  
Mass Migration ◽  
And Migration

This final chapter offers a conclusion to the overall findings of the journal. It summarises the core factors of mass migration: migration patterns and networks; the role of governments and immigration policy; the importance of steamship emigration agents; the business of migration; and the shifting role of ports and port infrastructures. It concludes by suggesting that maritime and migration historians can further their studies by expanding and exploring one another’s territories.

Study on the Properties of Aerodynamic Reference Sound Sources

2019 ◽  
Vol 105 (6) ◽  
pp. 960-969 ◽  
Author(s):  
Spyros Brezas ◽  
Volker Wittstock
Keyword(s):  
Ambient Temperature ◽  
Atmospheric Pressure ◽  
Rotation Speed ◽  
Near Field ◽  
Sound Power ◽  
Sound Sources ◽  
The Core ◽  
In Situ Conditions ◽  
Calibration Condition

Towards the establishment of traceability in sound power in airborne sound, the present study focuses on the dissemination procedure. Aerodynamic reference sound sources were studied as potential transfer standards. Initially, the sources were examined in the up-to-present requirements. The core of the study is the correction required for the transition from calibration to in situ conditions. The influence of atmospheric pressure, ambient temperature and fan rotation speed was investigated and the corresponding correction was determined. A comparison to an existing correction was also performed. Near field effects were another part of the study. The related uncertainty was estimated in a transparent approach. The dependency of the uncertainty on the in situ and calibration condition values is also presented.

scholarly journals THERMAL-HYDRAULIC ANALYSIS OF IRT-4M IN REACTIVITY INSERTION ACCIDENT AT VR-1 REACTOR

2016 ◽  
Vol 4 ◽  
pp. 22
Author(s):  
Filip Fejt
Keyword(s):  
Atmospheric Pressure ◽  
Room Temperature ◽  
Nuclear System ◽  
Hydraulic Analysis ◽  
Research Reactors ◽  
The Core ◽  
Fuel Assemblies ◽  
Coolant Circulation ◽  
Thermal Hydraulic Analysis ◽  
Reactivity Insertion

The paper deals with thermal-hydraulic analysis during reactivity insertion accident, i.e. a step increase of nuclear system reactivity by 0.7 eff, at VR-1 Reactor. The reactor utilizes IRT-4M type of fuel assemblies, and even though these fuel assemblies are designed for an operation at the high-power research reactors, they might be also used for zero-power reactors. The thermal-hydraulic analyses must take into account several specific assumptions that are derived from VR-1 reactor specifications. The reactor does not require a forced water flow for a fuel cooling, the core is placed in an open vessel with atmospheric pressure, and amount of coolant water in the vessel is sufficient for providing the inlet water at room temperature for the whole event. Coolant circulation is expected to be formed only by natural convection.

Parameter Measuring System Based on STM32

2013 ◽  
Vol 411-414 ◽  
pp. 922-925 ◽  
Author(s):  
Yao Liang Shi ◽  
Guang Yu Zheng ◽  
Li Wu ◽  
Shu Sheng Peng
Keyword(s):  
Atmospheric Pressure ◽  
Rotation Speed ◽  
Host Computer ◽  
Measuring System ◽  
Nand Flash ◽  
The Core ◽  
Temperature And Humidity ◽  
Parameter Measuring ◽  
Sd Card

A parameter measuring system is introduced in this paper, which is used for recording the temperature and humidity, atmospheric pressure, rotation speed and acceleration, etc. The system uses a 32-bit RISC microprocessor of STM32F103ZET6 based on the core of ARM Coretex-M3 as master chip. And it writes the data recorded to NAND FLASH. After it finishes, it copies the data to host-computer through SD card.

SEISMIC VELOCITY STUDY OF SYNTHETIC CORES

Geophysics ◽  
1957 ◽  
Vol 22 (4) ◽  
pp. 813-820 ◽  
Author(s):  
William O. Murphy ◽  
Joseph W. Berg ◽  
Kenneth L. Cook
Keyword(s):  
Elastic Wave ◽  
Elastic Waves ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Seismic Velocity ◽  
Pore Filling ◽  
The Core ◽  
Wave Velocities ◽  
Longitudinal Elastic Wave ◽  
Alcohol Benzene

The velocity of a longitudinal elastic wave through rock at room temperature and at atmospheric pressure depends upon the nature of the rock frame, the porosity of the rock, and the nature of the pore‐filling fluid. In the present investigation longitudinal elastic wave velocities were measured for sixty synthetic cores. The rock frame consisted of sorted quartz sand grains and cement, the percentage of cement varying from ten to fifty percent. The core porosities varied from 8.8 percent to 22 percent. The velocities were measured for dry air‐filled cores and for cores saturated with various liquids. These pore‐filling liquids were distilled water, ethyl alcohol, benzene, carbon tetrachloride, and chloroform. The measured velocities ranged from 2,360 feet per second to 14,710 feet per second. The wave velocity in liquid‐filled cores of 10 percent porosity was approximately twice the velocity for cores of 20 percent porosity, the same type of cement being used in both instances. For any given core, flooded with fluids of wave velocities ranging from 3,000 to 5,000 feet per second, the maximum observed variation in core velocity was around 20 percent. The experimental data fitted the empirical linear equation [Formula: see text] where [Formula: see text] of longitudinal elastic waves passing through the flooded core; [Formula: see text] of longitudinal elastic waves in passing through the saturating fluid. The constant k depends upon the porosity of the rock and the type of cement used. The constant, C, depends upon the nature of the rock frame.

scholarly journals CFD simulation of DC-discharge in airflow

2021 ◽  
Vol 2100 (1) ◽  
pp. 012015
Author(s):  
D A Tarasov ◽  
A A Firsov
Keyword(s):  
Atmospheric Pressure ◽  
Discharge Channel ◽  
Cfd Simulation ◽  
Fluid Model ◽  
Three Dimensional ◽  
Flow Discharge ◽  
The Core ◽  
Initial Discharge ◽  
Dc Discharge ◽  
Partial Channel

Abstract The main purpose of this work is to simulate a dynamics of DC discharge in a subsonic airflow. The calculations were performed in the FlowVision 3.12.01 software package. The single-fluid model (MHD approach) of equilibrium plasma was used while the initial discharge channel was set manually. Cylindrical coaxially arranged electrodes were located in the central part of the calculation area, in the core of the airflow. A 5A DC discharge at atmospheric pressure was considered, as well as a simple model of a re-breakdown between parts of discharge filament. In this work, three-dimensional distributions of temperature and current density were obtained during an evolution of discharge in a flow. Discharge channel extension by the airflow and partial channel decay after the re-breakdown process were shown.

Environmental Factors in the Evolution of Dorset Culture: A Marginal Proposal for Hudson Bay

1976 ◽  
Vol 31 ◽  
pp. 139-149 ◽  
Author(s):  
William Fitzhugh
Keyword(s):  
Environmental Factors ◽  
Geographic Area ◽  
Hudson Bay ◽  
Persistent Problem ◽  
Maximum Extension ◽  
Stylistic Evolution ◽  
The Core ◽  
Interacting Populations ◽  
Large Geographic Area ◽  
And Migration

Despite continued attention from archaeologists the origin of Dorset culture in the Eastern Arctic remains a persistent problem in northern prehistory. The transition from late Pre-Dorset to early Dorset culture is marked by a relatively rapid and consistent typological shift throughout a large geographic area at between about 1000 and 800 B.C. Although hampered by a distinct paucity of information, available chronological and distributional data do not supply a ready explanation for such consistent changes over such a wide-flung territory. However, the lack of a time slope and the presence of regional variants do not suggest that Dorset origins will be found in a single locale; rather, the transition appears to have occurred throughout a band of interacting populations within the core area of the eastern Central Arctic. Subsequent changes may be seen as a result of stylistic evolution, diffusion, and migration into more peripheral regions during the maximum extension of the Dorset sphere.

scholarly journals Crisis of Solidarity? Changing Welfare and Migration Regimes in Sweden

2016 ◽  
Vol 45 (1) ◽  
pp. 121-135 ◽  
Author(s):  
Magnus Dahlstedt ◽  
Anders Neergaard
Keyword(s):  
Human Rights ◽  
Vantage Point ◽  
The Other ◽  
European Countries ◽  
Social Fabric ◽  
The Core ◽  
Swedish Model ◽  
European Crisis ◽  
And Migration ◽  
Migration Regimes

Europe is in crisis. In recent years, there has been a rise of xenophobic parties in a number of European countries. While arguing that there is indeed a European crisis, this article focuses on the Swedish take on the crisis. The aim is to contribute to the understanding of migration, from a Swedish vantage point. This orientation has particular significance since Sweden has traditionally been extolled as defending human rights and multiculturalism by opening its doors to refugees – the so-called Swedish exceptionalism. Reality, however, is quite different and former policies are contested, raising the question whether this signals the end of this exceptionalism. In Sweden, ongoing processes are transforming the core social fabric of what was previously known as the Swedish model. It is potentially a bellwether for the transformation of a previously inclusive democratic society into something quite different, in which ‘the Other’ increasingly plays a defining role.

scholarly journals Promoting lentil germination and stem growth by plasma activated tap water, demineralized water and liquid fertilizer

RSC Advances ◽  
2017 ◽  
Vol 7 (50) ◽  
pp. 31244-31251 ◽  
Author(s):  
S. Zhang ◽  
A. Rousseau ◽  
T. Dufour
Keyword(s):  
Atmospheric Pressure ◽  
Tap Water ◽  
Stem Elongation ◽  
Germination Rate ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Stem Growth ◽  
Elongation Rate ◽  
Liquid Fertilizer ◽  
Demineralized Water

Tap water, demineralized water and liquid fertilizer have been activated using an atmospheric pressure plasma jet (APPJ) to investigate their benefits for the germination rate and stem elongation rate of lentils from Puy-en-Velay (France).

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