ACTIVITY OF TWO SPECIES OF CALLIPHORA (DIPTERA) DURING BAROMETRIC PRESSURE CHANGES OF NATURAL MAGNITUDE

1961 ◽  
Vol 39 (5) ◽  
pp. 623-635 ◽  
Author(s):  
D. K. Edwards
Keyword(s):  
Barometric Pressure ◽  
Flight Activity ◽  
Insect Species ◽  
Calliphora Vicina ◽  
Pressure Drops ◽  
Level Pressure ◽  
Previous Condition ◽  
Per Se ◽  
Pressure Changes ◽  
Experimental Pressure

The amount of flight activity of Calliphora vicina R.D. was monitored during (a) natural, diurnal, barometric pressure changes, and (b) experimental pressure changes of natural amounts and rates. Activity was increased by a change in trend from rising or level to falling pressure, or by two step-like drops of 1 millibar, each lasting 15 minutes, separated by 1 hour of level pressure. The change to falling pressure, not falling pressure per se. stimulated activity in C. vicina. Activity was little, if at all, affected by a change to rising pressure from a previous condition of falling or level pressure. With Calliphora vomitoria (L.) no effects of a changing pressure trend on activity were observed. These findings indicate that natural, and particularly prefrontal, pressure drops under certain conditions can influence the amount of activity of some insect species.

scholarly journals Research on HAR-Based Floor Positioning

2021 ◽  
Vol 10 (7) ◽  
pp. 437
Author(s):  
Hongxia Qi ◽  
Yunjia Wang ◽  
Jingxue Bi ◽  
Hongji Cao ◽  
Shenglei Xu
Keyword(s):  
Barometric Pressure ◽  
Air Pressure ◽  
Location Based Services ◽  
Sensor Data ◽  
Reference Station ◽  
Position Change ◽  
Radio Signals ◽  
Positioning Method ◽  
Pressure Changes

Floor positioning is an important aspect of indoor positioning technology, which is closely related to location-based services (LBSs). Currently, floor positioning technologies are mainly based on radio signals and barometric pressure. The former are impacted by the multipath effect, rely on infrastructure support, and are limited by different spatial structures. For the latter, the air pressure changes with the temperature and humidity, the deployment cost of the reference station is high, and different terminal models need to be calibrated in advance. In view of these issues, here, we propose a novel floor positioning method based on human activity recognition (HAR), using smartphone built-in sensor data to classify pedestrian activities. We obtain the degree of the floor change according to the activity category of every step and determine whether the pedestrian completes floor switching through condition and threshold analysis. Then, we combine the previous floor or the high-precision initial floor with the floor change degree to calculate the pedestrians’ real-time floor position. A multi-floor office building was chosen as the experimental site and verified through the process of alternating multiple types of activities. The results show that the pedestrian floor position change recognition and location accuracy of this method were as high as 100%, and that this method has good robustness and high universality. It is more stable than methods based on wireless signals. Compared with one existing HAR-based method and air pressure, the method in this paper allows pedestrians to undertake long-term static or round-trip activities during the process of going up and down the stairs. In addition, the proposed method has good fault tolerance for the misjudgment of pedestrian actions.

scholarly journals Air Movement in Snow Due to Windpumping

1989 ◽  
Vol 35 (120) ◽  
pp. 209-213 ◽  
Author(s):  
S.C. Colbeck
Keyword(s):  
Pore Space ◽  
Barometric Pressure ◽  
Surface Flows ◽  
Wind Speeds ◽  
Compression And Expansion ◽  
Strong Winds ◽  
Pressure Changes ◽  
Low Amplitude ◽  
Pressure Perturbations ◽  
Rapid Pressure

Abstract Strong winds can disrupt the thermal regime in seasonal snow because of the variation in surface pressure associated with surface features like dunes and ripples. Topographical features of shorter wavelengths produce stronger surface flows, but the flow decays rapidly with depth. Longer-wavelength features produce weaker surface flows but the flow decays more slowly with depth. The flow may only be strong enough to disrupt the temperature field for features of wavelengths on the scale of meters or tens of meters at wind speeds of 10 m/s or more. Other possible causes of windpumping have been examined but they do not appear to be as significant. Rapid pressure perturbations due to turbulence produce very little displacement of the air because of the high frequency and low amplitude. Barometric pressure changes cause compression and expansion of the air in the pore space, but the rate is too low to have much effect.

Metabolic Responses to Thermal Stressors of Altitude-Acclimated Rats

1958 ◽  
Vol 195 (3) ◽  
pp. 739-743 ◽  
Author(s):  
Henry B. Hale ◽  
Roy B. Mefferd
Keyword(s):  
Urine Volume ◽  
Temperature Response ◽  
Ground Level ◽  
Metabolic Responses ◽  
Control Group ◽  
Response Curves ◽  
Level Pressure ◽  
Metabolic Functions ◽  
Per Se ◽  
The Difference

Fasting 24-hour exposures of altitude-acclimated rats (380 mm Hg, 18,000 ft. simulated) to ground level pressure (750 mm Hg) at either cold (3°C), neutral (24°C), or hot (35°C) temperatures seldom resulted in return of their metabolic functions to preacclimative ‘normalcy.’ Although the control and altitude-acclimated groups both were accustomed to neutral temperatures (24° and 26°C), quantitative differences at ground level and altitude occurred in various indices of water, mineral and nitrogen metabolism. Of the 32 physiologic variables studied, only 4 (ratio of urine volume/ water intake, and urinary excretion of potassium, creatinine and glycine) failed to differentiate the responses of the altitude- and ground-accustomed rats. The temperature response curves of the altitude group tended to parallel the corresponding ones for the control group, but most variables were on higher or lower planes. The difference in plane resulted either from the effects of the return to ground level pressure, or from nonreversible effects of acclimation to altitude per se.

Effects of Thermal Conditioning on Metabolic Responses of Rats to Altitude

1958 ◽  
Vol 195 (3) ◽  
pp. 735-738 ◽  
Author(s):  
Roy B. Mefferd ◽  
Henry B. Hale
Keyword(s):  
Weight Loss ◽  
Uric Acid ◽  
Urinary Excretion ◽  
Glutamic Acid ◽  
Strong Influence ◽  
Urine Volume ◽  
Barometric Pressure ◽  
Metabolic Responses ◽  
Different Temperatures ◽  
Per Se

The metabolic responses of rats acclimated to different temperatures (3°, 24° and 35°C) were compared during a 24-hour fasting exposure to low barometric pressure (380 mm Hg). Determinations included fasting weight loss, water intake, urine volume and urinary excretion of Na, K, Mg, Ca, PO4, urea, uric acid, creatinine, creatine, taurine, ß-alanine, glycine, α-alanine, valine + methionine, serine, threonine, tyrosine, glutamic acid, aspartic acid, lysine, arginine and histidine. Since the altitude tests were made at a neutral temperature (25°C) the altitude responses, per se, were determined by comparing the ground and altitude responses of each acclimated group at neutral temperatures. These comparisons revealed that the acclimated state of the rats exercised a strong influence on the altitude response for most of the variables. There were significant intergroup differences in this response for all variables except phosphate, urea, taurine, valine + methionine, serine, histidine and the Mg/Ca ratio.

scholarly journals Effect of virtual mass force on prediction of pressure changes in condensing tubes

2012 ◽  
Vol 16 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Hamid Saffari ◽  
Nemat Daur
Keyword(s):  
Experimental Data ◽  
Annular Flow ◽  
Fluid Model ◽  
Mass Force ◽  
Virtual Mass ◽  
Vertical Pipe ◽  
Pressure Drops ◽  
Factors Affecting ◽  
Pressure Changes ◽  
Significant Factors

Three-fluid model is used to calculate the pressure drops in a vertical pipe with the annular flow pattern for condensing steam. The three-fluid models are based on the mass, momentum, and energy balance equations for each of the fluid streams in the annular flow. There are discrepancies between predictions of three-fluid model for pressure drops and the experimental data for pressure drops when using the avail?able correlations for steam-film interfacial friction. The correlation by Stevanovic et at provides good match with experimental data, but it does not take into account some important factors affecting the pressure drops in its three-fluid model. One of these significant factors which is considered in the three fluid model used in the present paper is virtual mass (added mass) force term. Inclusion of the virtual mass force improves the pressure drop predictions such that they agree much better with the experiments.

scholarly journals Preliminary observations of flight activity of Trichoptera in the southern Cape, South Africa

Zoosymposia ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 172-187
Author(s):  
FERDINAND C. DE MOOR ◽  
W. GEOFF McILLERON
Keyword(s):  
South Africa ◽  
Uv Light ◽  
Weather Conditions ◽  
Barometric Pressure ◽  
Flight Activity ◽  
Light Sources ◽  
Western Cape ◽  
Egg Masses ◽  
A Site ◽  
Activity Information

In a study on flight activity it was observed that Trichoptera were attracted to a superactinic or UV light at a site along the lower Groot River near Nature’s Valley in the Western Cape, South Africa. The frequency of insects passing selected fixed points in space was recorded photographically, after dusk, on 44 days between October 2011 and May 2012. All digital images of insects were identified to species, where possible, and abundance of species over selected time periods was determined. Water and air temperature, relative humidity, barometric pressure, wind direction and speed were continuously recorded during each recording event. Total dissolved solids (TDS), electrical conductivity, pH, the percentage of cloud cover, rain at the time of the survey, and rainfall prior to the survey, were all recorded. The dominant species during all surveys, Athripsodes bergensis Scott, revealed a modal peak of flight activity around 50 minutes after sunset which was strongly influenced by climatic variation. The presence of egg masses carried by females was observed from the middle of November through March, with the highest percentage of females with egg masses found from late November to early December. Other species of Trichoptera that were recorded flying appeared later after sunset than did A. bergensis. Statistically the most important factor influencing flight activity was the time in minutes after sunset. Clear, cloudless conditions resulted in reduced flight activity. Information on flight activity can be used to determine the optimum weather conditions and times for collecting Trichoptera when using light sources.

scholarly journals Hydraulic transients for a pipe line network of treated effluent rising main using SAP 2R

2021 ◽  
Author(s):  
Ajmal Hussain ◽  
Muhammad Mustafa ◽  
Hazi Mohammad Azamathullah ◽  
M. R. Sadique
Keyword(s):  
Direct Result ◽  
Hydraulic Transients ◽  
Pressure Drops ◽  
Treated Effluent ◽  
Pipe Line ◽  
Safe Limit ◽  
Protection Devices ◽  
Pressure Changes ◽  
Line Network ◽  
Simulated Scenario

Abstract Hydraulic transients occur as a direct result of rapid variations of flow field in pressurized systems. The change in velocity from valve closures or pump operations causes pressure surges that are propagated away from the source throughout the pipeline. The associated pressure changes during a transient period are quite large and occur quickly (within a few seconds). It should also be noted that when the maximum pressures exceed the bar ratings (mechanical strength) of the piping material, failure can occur. Similarly, if the minimum pressure drops below the vapour pressure of the fluid, cavitation can occur. The purpose of the present study is to model and simulate the hydraulic transients in a pipeline network system of treated effluent rising main of Mpophomeni sanitation scheme using SAP 2R. A total of five scenarios were simulated using different combinations. The simulation results show that the transient pressures in the pipeline exceeded the bar rating of the pipe where the bursts or cavitation may occur for the simulated scenario, but transient pressures were reduced to a safe limit after providing water hammer protection devices.

Influence of Barometric Pressure Changes on Ventilation Conditions in Deep Mines

2014 ◽  
Vol 59 (3) ◽  
pp. 621-639 ◽  
Author(s):  
Stanisław Wasilewski
Keyword(s):  
Methane Concentration ◽  
Pressure Sensors ◽  
Mining Industry ◽  
Barometric Pressure ◽  
Pressure Change ◽  
Absolute Pressure ◽  
Mine Workings ◽  
Pressure Changes ◽  
Strategic Project ◽  
Ventilation Conditions

Abstract Barometric air pressure and its changes have a critical impact on ventilation conditions in the underground workings of deep mines. Changes in pressure are particularly important because they are responsible for the transient states of ventilation conditions, therefore, assessing the scale of pressure change is essential. Unfortunately, previously for many years in the Polish mining industry barometric pressure was recorded only on tapes of mechanical barographs by the ventilation department on the surface and therefore such dependencies of methane concentration due to barometric pressure changes have not been properly documented. Today, after the implementation in mines of instruments enabling the monitoring of absolute pressure in the workings of mines (Wasilewski, 2009) the conditions have been created to study the influence of pressure changes on changes of air parameters in the mine workings. Barometric pressure changes were observed and recorded over a course of approximately two years using monitoring system that utilized high accuracy pressure sensors on the surface and in selected workings of an underground mine. This paper presents a statistical analysis of the data that we generated from assessing pressure changes on the surface and at selected underground points in the mine. In the article, which presents the results of the first part of the study, some examples of when significant changes in pressure prior to the tragic events, which were not accompanied by changes in the methane concentration in mine workings, will also be shown. Interestingly, we found that the relationship between methane ignitions and explosions in longwall gob mined via the cave-in method is associated with changes in the barometric pressure. Several instances of methane ignitions and explosions in the gob of cave-in longwalls in recent years were compared with background barometric pressure changes. Research carried out in within the strategic project “Improving work safety in the mines” allowed to record air parameters changes inside the gob of longwalls and show the influence of pressure changes on changes in methane and oxygen concentration in the gob, which will be shown in the second part of the article to be published in the near future.

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