scholarly journals Amplitude of sound waves in pipes

1926 ◽  
Vol 112 (762) ◽  
pp. 522-541 ◽  
Keyword(s):  
Optical Method ◽  
Sound Waves ◽  
Temperature Changes ◽  
Rapid Changes ◽  
Periodic Pressure ◽  
Air Motion ◽  
Organ Pipe ◽  
Pressure Changes ◽  
Considerable Doubt

There has always existed considerable doubt as to the magnitude of the periodic pressure changes, and the concomitant velocity and temperature changes which the air in a sounding organ pipe undergoes. The difficulty of following these rapid changes has prevented the success of many attempts, and results obtained by a few successful experimenters have not been in agreement. Kundt, and, later, Dvorak, using a manometer provided with a valve, which opened and shut with the frequency of the air oscillations in the pipe, measured the cumulative pressure of the condensations. Töpler and Boltzmann used an optical method. That part of a stopped pipe close to the node was fitted with glass windows and placed between the plates of a Jamin interferometer, so that part of the light which produced the interference bands in the instrument passed through and part outside the pipe. The interference bands appeared to be broadened when the pipe was sounded; from the extent of the broadening, the change of density or of pressure at the node due to the vibration was calculated. Raps obtained actual photographs of the oscillating bands, which the optical fatigue of the eye made to appear widened in the earlier experiments. A summary of their results is given in Table I. Of course, the oscillatory change of pressure will depend on the form of the pipe and the pressure at which it is blown, but with the average stopped diapason, blown at a few inches of water, the discrepancy between the results by different methods is still too great. Against the valve-manometer the criticism may be levelled that the motion of the air in the pipe is seriously affected by the motion of the valve pallet, which will cause additional variations of pressure in the pipe. Kundt's values are the highest (his maximum recorded amplitude was 1/16 atmosphere); Töpler and Boltzmann recorded 1/60, Raps 1/22. Interference methods have the advantage of leaving the air entirely undisturbed, but are troublesome both int their adaptation to existing pipes and in their interpretation, while slight vibration of the walls under the action of the sound waves or the blast produces shifts of the bands of the same order as those sought for in the air motion.

scholarly journals Forensic Engineering Techniques For Testing And Predicting Lp-Gas Container Relief Venting

2004 ◽  
Vol 21 (2) ◽  
Author(s):  
James A. Petersen
Keyword(s):  
Test Data ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Temperature Changes ◽  
Flammable Gas ◽  
Forensic Engineering ◽  
Pressure Changes ◽  
Liquefied Gas

When An Lp-Gas Container Is Involved In A Fire, Flammable Gas Is Usually Vented From The Relief Valve. One Of The First Questions Is Whether The Container Vented The Gas That Caused The Fire Or Whether Gas Was Vented Due To The Fire Heating The Container. If The Relief Valve Vents Gas That Initiates The Fire, It Is Usually Due To An Overfilled Container. This Paper Discusses; 1) The Prediction Of The Rate Of Container Warming Due To Normal Temperature Changes, 2) The Resulting Pressure Changes Of The Liquefied Gas, 3) The Reaction Of The Pressure Relief Valve And The Quantity Of Lp-Gas Vented During The Operation Of The Relief Valve, 4) Designing The Experiment And 4) Adjusting The Model To Reflect Test Data.

Seismic ocean thermometry

Science ◽  
2020 ◽  
Vol 369 (6510) ◽  
pp. 1510-1515 ◽  
Author(s):  
Wenbo Wu ◽  
Zhongwen Zhan ◽  
Shirui Peng ◽  
Sidao Ni ◽  
Jörn Callies
Keyword(s):  
Deep Ocean ◽  
Warming Trend ◽  
Sound Waves ◽  
Temperature Changes ◽  
East Indian ◽  
Repeating Earthquakes ◽  
Basin Scale ◽  
Sampling Problem ◽  
Ocean Monitoring ◽  
East Indian Ocean

More than 90% of the energy trapped on Earth by increasingly abundant greenhouse gases is absorbed by the ocean. Monitoring the resulting ocean warming remains a challenging sampling problem. To complement existing point measurements, we introduce a method that infers basin-scale deep-ocean temperature changes from the travel times of sound waves that are generated by repeating earthquakes. A first implementation of this seismic ocean thermometry constrains temperature anomalies averaged across a 3000-kilometer-long section in the equatorial East Indian Ocean with a standard error of 0.0060 kelvin. Between 2005 and 2016, we find temperature fluctuations on time scales of 12 months, 6 months, and ~10 days, and we infer a decadal warming trend that substantially exceeds previous estimates.

Measurement of Temperature and Heat Flux Changes During the Fixing Process in Electrophotographic Machines

1996 ◽  
Vol 118 (1) ◽  
pp. 150-154 ◽  
Author(s):  
T. Mitsuya ◽  
K. Masuda ◽  
Y. Hori
Keyword(s):  
Heat Flux ◽  
Print Quality ◽  
Two Dimensional ◽  
Temperature Changes ◽  
One Dimensional ◽  
Temperature Heat ◽  
Rapid Temperature ◽  
Pressure Changes ◽  
The Relationship ◽  
Electrophotographic Printing

Increasingly higher speeds of modern electrophotographic printing force examination of the problem of retaining sufficient fixing strength without deterioration of print quality. In the nip region between the two rollers where fixing occurs, the significant parameters are temperature, heat flux, and pressure changes. Their optimization is necessary to maintain both speed and print quality. Difficulty in analyzing the relationship among these parameters occurs because of the complexity of two-dimensional phenomena in a rotating field and the rapidity of changes. Experimental equipment to measure relative heat flux in the nip region during rapid temperature changes was designed. Two sensors are installed in the heat roller. An adiabatic piece is buried under sensor 1. Sensor 2, without an adiabatic piece, detects temperature. Sensor 1 is electrically heated and always at the same temperature as sensor 2. Heat flux changes are obtained by noting the electric power supplied to sensor 1. The equipment was fabricated and measurements were made. They indicate an intermittent two-dimensional heat flux. Because of this, temperature decreases rapidly before the entrance to the nip region. Estimates of two-dimensional effects are made and modified for a one-dimensional case. From them, the temperature field in the nip region for actual fixing conditions is calculated.

scholarly journals Distributions of Hydrodynamic Pressure in the Gap of Slide Journal Bearing Lubricated with Ferro-Oil

2019 ◽  
Vol 26 (4) ◽  
pp. 53-61
Author(s):  
Marcin Frycz
Keyword(s):  
Magnetic Particles ◽  
Journal Bearing ◽  
Research Work ◽  
Hydrodynamic Pressure ◽  
Qualitative And Quantitative Analysis ◽  
Oil Viscosity ◽  
Temperature Changes ◽  
Pressure Distributions ◽  
Pressure Changes ◽  
The Magnetic Field

AbstractThis research work is part of a broader comprehensive issue, which is the analysis of flow and operating parameters of journal slide bearings lubricated with ferro-oil. In this article, the author presents only the main assumptions and essential transformations of the analytical and numerical model for determining the pressure distributions in the gap of a slide journal bearing lubricated with ferro-oil. It is cardinal that the rheological and magnetic values of ferro-oil parameters adopted in numerical calculations are based on the results of actual values obtained in the author’s earlier research work. There are presented the pressure distributions by abovementioned method in the article for cases of bearings lubricated with ferro-oils with different concentration of magnetic particles. The obtained results are shown in the form of a set of four complementary characteristics of the dimensionless pressure distributions. First and main of them are the calculations for classical Newtonian lubrication but they take into account the influence of the magnetic field on the distributions. The next of the presented characteristics are so-called “corrections” of pressure distribution values, taking into account as follows: effects of changes in ferro-oil viscosity related to temperature changes, impacts of ferro-oil viscosity changes related to pressure changes and the effect of non-oil properties of the lubricant. The article includes a qualitative and quantitative analysis of the obtained results as well as observations and conclusions are presented in it.

scholarly journals Aspects of anthropotechnics reliability of materials and products for non-collapsible and collapsible systems in high-rise construction

2019 ◽  
Vol 135 ◽  
pp. 03056
Author(s):  
Ruben Kazaryan
Keyword(s):  
Construction Industry ◽  
Climatic Conditions ◽  
Engineering Systems ◽  
Temperature Changes ◽  
High Rise ◽  
Periodic Inspection ◽  
Inspection And Maintenance ◽  
Pressure Changes ◽  
Expensive Process ◽  
Fundamental Direction

In engineering systems, which are used in construction industry and its production (buildings, constructions, roads), two fundamentally different ways of mechanical joint are used: non-collapsible and collapsible. Some architects relate non-collapsible objects to monolithic and consider their recycling as a difficult and expensive process. Compression joints on self-locking fittings can be considered as non-collapsible as well. A compression connection cannot be disassembled without destroying. Collapsible joint differs from non-collapsible by the following features: 1. You can disassemble it to original components according to a prior technology, identify and change defective elements or add some other components. 2. It requires periodic inspection and maintenance because of climatic conditions (temperature changes, pressure changes, wind loads, etc.), and the specificity of operation of this joint leads to a decrease in its mechanical properties. 3. It is forbidden to make them monolithic, so collapsible joints are mounted in an accessible way. Collapsible finishing system is a new fundamental direction of building reconstruction in the TTS system “man-technologyenvironment” in high-rise construction objects.

scholarly journals A MECHANISM FOR TRANSPORT OF SUBSTANCES BY TEMPERATURE-INDUCED PRESSURE GRADIENTS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 626e-626
Author(s):  
Kenneth A. Corey ◽  
Zhi Yi Tan
Keyword(s):  
Internal Pressure ◽  
Pressure Change ◽  
Temperature Gradients ◽  
Diurnal Changes ◽  
Pressure Gradients ◽  
Tomato Plants ◽  
Temperature Changes ◽  
Soil Temperatures ◽  
Pressure Changes ◽  
Gas Pressures

Diurnal changes in air and soil temperatures lead to temperature gradients between air and soil, between roots and shoots, and within plant organs. In response to these gradients, fluctuations in gas pressures may develop in organs that are resistant to exchange of gases. These fluctuations may regulate mass flow of gases or solutions within plants. Patterns of diurnal temperature changes were generated to illustrate temperature gradients between roots and shoots. Experimental confirmation of pressure changes induced by temperature differences between roots and shoots were measured with water manometers attached to stumps of detopped tomato plants. When roots were maintained 8 C lower than shoots, internal pressure decreased by 22 cm H2O. Reversing the direction of the temperature gradient led to an approximately equal and opposite pressure change and to sap movement. These results support a hypothesis that internal pressure gradients resulting from temperature gradients contribute to transport of substances in plants.

scholarly journals Intensity level as sustainable energy: Analysis of the conversion of energy stored on cicadas sound waves

2021 ◽  
Vol 10 (2) ◽  
pp. 201-210
Author(s):  
Rofiqul Umam ◽  
Endah Kinarya Palupi ◽  
Khusnul Yakin ◽  
Mochamad Iqbal ◽  
Rahmat Nawi Siregar ◽  
...  
Keyword(s):  
Rural Areas ◽  
Energy Analysis ◽  
Weather Conditions ◽  
Acoustic Power ◽  
Intensity Level ◽  
Sound Waves ◽  
Data Logger ◽  
Temperature Changes ◽  
Time Variations ◽  
Level Meter

In this study, the researchers measured cicadas' sound waves, considering that cicadas are mostly found in rural areas. The intensity level meter (AMTAST AMF003) was used with time variations (9:00 JST; 12:00 JST; and 15:00 JST). Measurements of air temperature differences (Krisbow Temperature Humidity Data Logger) were also carried out, and weather conditions were also considered in data collection using satellite data from Himawari, Japan. The interpretation results of intensity level's trend measured at 3:00 pm JST were decreased concerning the changes in days. Meanwhile, the measurement at 09:00 am and 12:00 pm JST did not show a decrement concerning the changes in days (31 days in total). These results show that temperature changes (towards autumn) can affect the intensity level of sound waves. In addition, slightly different intensity levels can affect large changes in acoustic power or the produced sound.

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