scholarly journals Novel Approach to Computing Critical and Normal Depth in Circular Channels

2021 ◽  
Vol 8 (6) ◽  
pp. 923-927
Author(s):  
Akram K. Mohammed ◽  
Raad H. Irzooki ◽  
Asmaa A. Jamel ◽  
Wesam S. Mohammed-Ali ◽  
Suhad S. Abbas

The critical depth and normal depth computation are essential for hydraulic engineers to understanding the characteristics of varied flow in open channels. These depths are fundamental to analyze the flow for irrigation, drainage, and sewer pipes. Several explicit solutions to calculate critical and normal depths in different shape open channels were discovered over time. Regardless of the complexity of using these explicit solutions, these formulas have a significant error percentage compared to the exact solution. Therefore, this research explicitly calculates the normal and critical depth in circular channels and finds simple, fast, and accurate equations. First, the dimensional analysis was used to propose an analytical equation for measuring the circular channels' critical and normal depths. Then, regression analysis has been carried for 2160 sets of discharge versus critical and normal depths data in a circular open channel. The results show that this study's proposed equation for measuring the circular channels' critical and normal depths overcomes the error percentage in previous studies. Furthermore, the proposed equation offers efficiency and precision compared with other previous solutions.

2020 ◽  
Vol 42 (1) ◽  
pp. 37-103
Author(s):  
Hardik A. Marfatia

In this paper, I undertake a novel approach to uncover the forecasting interconnections in the international housing markets. Using a dynamic model averaging framework that allows both the coefficients and the entire forecasting model to dynamically change over time, I uncover the intertwined forecasting relationships in 23 leading international housing markets. The evidence suggests significant forecasting interconnections in these markets. However, no country holds a constant forecasting advantage, including the United States and the United Kingdom, although the U.S. housing market's predictive power has increased over time. Evidence also suggests that allowing the forecasting model to change is more important than allowing the coefficients to change over time.


2011 ◽  
Vol 10 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Byung-Cheol Kim ◽  
Seungwoo Oh ◽  
Kwangyun Wohn

We present a novel approach to woven-cloth simu-lation in order to generate persistent wrinkles and folds. For a couple of decades, our community has identified and mimicked non-linear buckling of cloth based on the mechanical measure-ment of cloth. It has, however, scarcely paid attention to another important aspect of the measurement, the hysteresis of cloth be-haviors, which is the lag of the amount of forces between stress and relaxation. Our interpretation of the measurement indicates that persistent wrinkles and folds develop in part from the hyste-resis of cloth and its associated energy loss. Thus, we establish an adaptive energy model which takes stiffness coefficients and rest posture values not as constants but as variables over time and behavior. As stiffness coefficients and rest posture values change in proportion to the amount of the energy loss, they appear as persistent wrinkles and folds. Consequently, the clothes simulated by our method bring more realism with respect to visual identi-fication for past behaviors of cloth.


2021 ◽  
pp. 326-337
Author(s):  
Andrew V. Z. Brower ◽  
Randall T. Schuh

This chapter examines molecular clocks and time trees. Although laden with numerous process assumptions that may or may not be true (or knowable), the idea is appealingly straightforward: if amino acid substitutions in proteins occurred at a relatively steady pace that were more or less constant both over time and along each of the branches of a diverging evolutionary tree, then the number of substitutions would be directly related to the time since the taxa in question diverged from one another. However, evidence does not support a universal molecular clock. Evidence might or might not support “local” clocklike evolution among closely related taxa over relatively short time spans. Although absolute minimum ages for clades may be inferred from fossils, from biogeographical patterns, or extrapolated from secondary calibrations, such age estimates are subject to potentially significant error due to vagaries of geological dating as well as ambiguities of fossil identity. The test of a time tree hypothesis is to discover new fossil evidence that corroborates or falsifies it.


2020 ◽  
Vol 9 (1) ◽  
pp. 34
Author(s):  
Luigi Barazzetti ◽  
Mattia Previtali ◽  
Marco Scaioni

The identification of deterioration mechanisms and their monitoring over time is an essential phase for conservation. This work aimed at developing a novel approach for deterioration mapping and monitoring based on 360° images, which allows for simple and rapid data collection. The opportunity to capture the whole scene around a 360° camera reduces the number of images needed in a condition mapping project, resulting in a powerful solution to document small and narrow spaces. The paper will describe the implemented workflow for deterioration mapping based on 360° images, which highlights pathologies on surfaces and quantitatively measures their extension. Such a result will be available as standard outputs as well as an innovative virtual environment for immersive visualization. The case of multi-temporal data acquisition will be considered and discussed as well. Multiple 360° images acquired at different epochs from slightly different points are co-registered to obtain pixel-to-pixel correspondence, providing a solution to quantify and track deterioration effects.


2020 ◽  
Vol 12 (23) ◽  
pp. 3974
Author(s):  
Marino Mangeruga ◽  
Alessandro Casavola ◽  
Francesco Pupo ◽  
Fabio Bruno

In scientific and technical diving, the survey of unknown or partially unexplored areas is a common task that requires an accurate planning for ensuring the optimal use of resources and the divers’ safety. In particular, in any kind of diving activity, it is essential to foresee the “dive profile” that represents the diver’s exposure to pressure over time, ensuring that the dive plan complies with the specific safety rules that have to be applied in accordance with the diver’s qualification and the environmental conditions. This paper presents a novel approach to dive planning based on an original underwater pathfinding algorithm that computes the best 3D path to follow during the dive in order to be able to maximise the number of points of interest (POIs) visited, while taking into account the safety limitations. The proposed approach, for the first time, considers the morphology of the 3D space in which the dive takes place to compute the best path, taking into account the decompression limits and avoiding the obstacles through the analysis of a 3D map of the site. Moreover, three different cost functions are proposed and evaluated to identify the one that could suit the divers’ needs better.


2020 ◽  
Vol 8 (9) ◽  
pp. 1449
Author(s):  
Steven Gayder ◽  
Michael Parcey ◽  
Darlene Nesbitt ◽  
Alan J. Castle ◽  
Antonet M. Svircev

Bacteriophages are viruses capable of recognizing with high specificity, propagating inside of, and destroying their bacterial hosts. The phage lytic life cycle makes phages attractive as tools to selectively kill pathogenic bacteria with minimal impact on the surrounding microbiome. To effectively harness the potential of phages in therapy, it is critical to understand the phage–host dynamics and how these interactions can change in complex populations. Our model examined the interactions between the plant pathogen Erwinia amylovora, the antagonistic epiphyte Pantoea agglomerans, and the bacteriophages that infect and kill both species. P. agglomerans strains are used as a phage carrier; their role is to deliver and propagate the bacteriophages on the plant surface prior to the arrival of the pathogen. Using liquid cultures, the populations of the pathogen, carrier, and phages were tracked over time with quantitative real-time PCR. The jumbo Myoviridae phage ϕEa35-70 synergized with both the Myoviridae ϕEa21-4 and Podoviridae ϕEa46-1-A1 and was most effective in combination at reducing E. amylovora growth over 24 h. Phage ϕEa35-70, however, also reduced the growth of P. agglomerans. Phage cocktails of ϕEa21-4, ϕEa46-1-A1, and ϕEa35-70 at multiplicities of infections (MOIs) of 10, 1, and 0.01, respectively, no longer inhibited growth of P. agglomerans. When this cocktail was grown with P. agglomerans for 8 h prior to pathogen introduction, pathogen growth was reduced by over four log units over 24 h. These findings present a novel approach to study complex phage–host dynamics that can be exploited to create more effective phage-based therapies.


1993 ◽  
Vol 20 (3) ◽  
pp. 536-539 ◽  
Author(s):  
Willi H. Hager

Based on a large number of experiments, a simple formula is developed for the time-averaged free surface profile of a classical hydraulic jump. This novel approach is based on the length of the roller. The resulting surface profile fits the data well for usual inflow Froude numbers in the range of 2 to 10. Key words: backwater, channel flow, hydraulics, open channel, surface profile.


2015 ◽  
Vol 29 (9) ◽  
pp. 795-807 ◽  
Author(s):  
Susanne Winiwarter ◽  
Brian Middleton ◽  
Barry Jones ◽  
Paul Courtney ◽  
Bo Lindmark ◽  
...  

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