scholarly journals CONSIDERATION ON PRESSURE LOSS PER UNIT LENGTH OF PIPELINE FOR EACH MIX-PROPORTIONS IN CONCRETE PUMPING METHODS

2018 ◽  
Vol 83 (751) ◽  
pp. 1217-1227
Author(s):  
Atsunori MIYATA ◽  
Yoshihisa NAKATA ◽  
Shuzo OTSUKA
Keyword(s):  
Pressure Loss ◽  
Unit Length ◽  
Concrete Pumping

Optimization of fresh concrete pumping pressure loss with CFD-DEM approach

2021 ◽  
Vol 276 ◽  
pp. 122204
Author(s):  
Shengqiang Jiang ◽  
Xiaodong Chen ◽  
Guodong Cao ◽  
Yuanqiang Tan ◽  
Xiangwu Xiao ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Fresh Concrete ◽  
Concrete Pumping

Pressure Drop Testing of Corrugated Stainless Steel Pliable Gas Tubing (PLT)

2014 ◽  
Author(s):  
Bharadwaj Srinivasan ◽  
Stephen A. Idem
Keyword(s):  
Reynolds Number ◽  
Stainless Steel ◽  
Cross Section ◽  
Pressure Loss ◽  
Volume Flow Rate ◽  
Unit Length ◽  
Volume Flow ◽  
Coefficient Of Determination ◽  
Horizontal Pipe ◽  
Curve Fit

Pressure loss tests were conducted on straight corrugated stainless steel pliable gas tubing (PLT) per I.S. EN 15266:2007 [1]. A power law least-squares curve fit was used to relate pressure loss per unit length as a function of volume flow rate. For every case considered the calculated coefficient of determination values exceeded 0.90, indicating suitable correlation. Based on the curve fit expressions gas discharge graphs for the volume flow that would yield a pressure loss of 1 mbar were generated as a function of PLT length and diameter. Darcy friction factors were calculated from test data for each case and plotted on the Moody diagram as a function of Reynolds number based on the minimum PLT cross section. For Reynolds numbers less than 2300 the pressure loss data for PLT yielded an inverse relationship between the Darcy friction factor and the Reynolds number. In those instances the proportionality coefficient equaled 49, which differs from the value of 64 that can be derived analytically for steady laminar flow in a uniform cross section horizontal pipe.

scholarly journals Studies on the Pressure Loss Attendant with Super Workable Concrete Pumping

1999 ◽  
Vol 10 (1) ◽  
pp. 25-39
Author(s):  
Hideaki Taniguchi ◽  
Kazuki Masuda ◽  
Sakae Ushijima
Keyword(s):  
Pressure Loss ◽  
Concrete Pumping

scholarly journals OPTIMIZATION OF DIFFERENTIAL PRESSURE DISTRIBUTION BETWEEN GAS SUPPLY SYSTEM SECTIONS

2020 ◽  
Vol 22 (6) ◽  
pp. 141-153
Author(s):  
O. N. Medvedeva ◽  
N. S. Bessonova
Keyword(s):  
Pressure Distribution ◽  
Pressure Loss ◽  
Distribution Systems ◽  
Gas Flow ◽  
Unit Length ◽  
Supply System ◽  
Differential Pressure ◽  
Strategic Factors ◽  
Supply Systems ◽  
Gas Supply

The paper proposes the optimum distribution of the differential pressure between gas supply system sections and gas consumption, depending on the settlement planning and development. This provides a 10–15 % reduction in metal and material consumption of gas supply systems and a 4–5 % cost reduction. The hydraulic analysis of differential pressure distribution does not allow to purposefully distribute the calculated pressure drop. The pipeline diameter is usually selected according to the estimated gas flow rate and specific pressure loss per unit length of gas supply system sections. Then, in accordance with the State standard, the condition of compliance and non-exceedance of the obtained differential pressure is checked with the standard value. If this condition is not met, the pipeline diameter is adjusted for design reasons.This work conducts additional research into the differential pressure distribution between gas supply system sections. Materials and methods include the assessment methodology for the effectiveness of differential pressure distribution between gas supply system sections.Although many publications are devoted to the optimization of gas pressure distribution systems, the proposed solutions and the recommendations developed in this paper are fragmentary, often contradictory, since they do not consider the completeness and diversity of strategic factors.The paper shows that the pressure loss values obtained for domestic gas-based units with a reduced nominal pressure, are much less than those given in regulatory documents. According to the analysis, the settlement development, population density in gas-supplied territories, and technical conditions of gas-supplied buildings, have a decisive influence on the unit costs of gas supply systems.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

Review on the aerodynamics of intermediate compressor duct

2020 ◽  
Vol 14 (4) ◽  
pp. 7446-7468
Author(s):  
Manish Sharma ◽  
Beena D. Baloni
Keyword(s):  
High Pressure ◽  
Pressure Loss ◽  
Flow Analysis ◽  
Outer Wall ◽  
Optimization Techniques ◽  
Optimum Pressure ◽  
Research Areas ◽  
Static Pressure Distribution ◽  
High Pressure Compressor ◽  
Pressure Compressor

In a turbofan engine, the air is brought from the low to the high-pressure compressor through an intermediate compressor duct. Weight and design space limitations impel to its design as an S-shaped. Despite it, the intermediate duct has to guide the flow carefully to the high-pressure compressor without disturbances and flow separations hence, flow analysis within the duct has been attractive to the researchers ever since its inception. Consequently, a number of researchers and experimentalists from the aerospace industry could not keep themselves away from this research. Further demand for increasing by-pass ratio will change the shape and weight of the duct that uplift encourages them to continue research in this field. Innumerable studies related to S-shaped duct have proven that its performance depends on many factors like curvature, upstream compressor’s vortices, swirl, insertion of struts, geometrical aspects, Mach number and many more. The application of flow control devices, wall shape optimization techniques, and integrated concepts lead a better system performance and shorten the duct length.  This review paper is an endeavor to encapsulate all the above aspects and finally, it can be concluded that the intermediate duct is a key component to keep the overall weight and specific fuel consumption low. The shape and curvature of the duct significantly affect the pressure distortion. The wall static pressure distribution along the inner wall significantly higher than that of the outer wall. Duct pressure loss enhances with the aggressive design of duct, incursion of struts, thick inlet boundary layer and higher swirl at the inlet. Thus, one should focus on research areas for better aerodynamic effects of the above parameters which give duct design with optimum pressure loss and non-uniformity within the duct.

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