scholarly journals Parallel-middle-body and Stern-form Relative Significance in the Wake Formation of Single-screw Large Ships

2017 ◽  
Vol 8 (1) ◽  
pp. 92
Author(s):  
Ketut Suastika ◽  
Fajar Nugraha ◽  
I Ketut Aria Pria Utama
1973 ◽  
Vol 95 (1) ◽  
pp. 81-90 ◽  
Author(s):  
S. Y. Poon

A simple numerical procedure is proposed for the solution of the two-dimensional power-law flow equations for a wide channel with a moving boundary. The results are used to construct a complete model of the isothermal operation of a single-screw extruder in terms of the compression ratio, the relative lengths of the compression and the metering sections, and the power-law index of the material. It is shown that a number of the main features of screw extrusion are predicted by the model. By way of examples it is shown that, in application, the isothermal condition can be relaxed, and satisfactory correlation between the theory and experiment can be obtained, by the use of an average extrusion temperature. The model provides a broad theoretical framework, by which the relative significance of the geometric parameters and the power-law index on the throughput-pressure characteristics of the screw extrusion can be examined, and the experimental results collated and extrapolated. Examples of the solution are presented in the form of contour plots to assist designers and users of single-screw pumping machines.


2000 ◽  
Vol 2 (3) ◽  
pp. 222-225 ◽  
Author(s):  
Neal D. Goldman ◽  
Ramsey Alsarraf ◽  
Gary Nishioka ◽  
Wayne F. Larrabee
Keyword(s):  

1989 ◽  
Vol 4 (4) ◽  
pp. 232-241 ◽  
Author(s):  
A. R. Vincelette ◽  
C. S. Guerrero ◽  
P. J. Carreau ◽  
P. G. Lafleur
Keyword(s):  

2009 ◽  
Vol 24 (2) ◽  
pp. 106-113 ◽  
Author(s):  
M. Kurte-Jardin ◽  
H. Potente ◽  
K. Sigge ◽  
M. Bornemann

Hand ◽  
2021 ◽  
pp. 155894472097411
Author(s):  
Luke T. Nicholson ◽  
Kristen M. Sochol ◽  
Ali Azad ◽  
Ram Kiran Alluri ◽  
J. Ryan Hill ◽  
...  

Background: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. Methods: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. Results: Stiffness during load to failure was not significantly different between single- and double-screw configurations ( P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct ( P = .029). Conclusions: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.


Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 669
Author(s):  
Abid Sarwar ◽  
Sajid Rashid Ahmad ◽  
Muhammad Ishaq Asif Rehmani ◽  
Muhammad Asif Javid ◽  
Shazia Gulzar ◽  
...  

The changing climate and global warming have rendered existing surface water insufficient, which is projected to adversely influence the irrigated farming systems globally. Consequently, groundwater demand has increased significantly owing to increasing population and demand for plant-based foods especially in South Asia and Pakistan. This study aimed to determine the potential areas for groundwater use for agriculture sector development in the study area Lower Dir District. ArcGIS 10.4 was utilized for geospatial analysis, which is referred to as Multi Influencing Factor (MIF) methodology. Seven parameters including land cover, geology, soil, rainfall, underground faults (liniment) density, drainage density, and slope, were utilized for delineation purpose. Considering relative significance and influence of each parameter in the groundwater recharge rating and weightage was given and potential groundwater areas were classified into very high, high, good, and poor. The result of classification disclosed that the areas of 113.10, 659.38, 674.68, and 124.17 km2 had very high, high, good, and poor potential for groundwater agricultural uses, respectively. Field surveys for water table indicated groundwater potentiality, which was high for Kotkay and Lalqila union councils having shallow water table. However, groundwater potentiality was poor in Zimdara, Khal, and Talash, characterized with a very deep water table. Moreover, the study effectively revealed that remote sensing and GIS could be developed as potent tools for mapping potential sites for groundwater utilization. Furthermore, MIF technique could be a suitable approach for delineation of groundwater potential zone, which can be applied for further research in different areas.


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