scholarly journals Fish Ladder Geometrical Sizes and Hydraulic Performances. Experimental Approach

2019 ◽  
Vol 112 ◽  
pp. 02014
Author(s):  
Cristina-Catalina Petica ◽  
Carmen-Anca Safta ◽  
Irina Pincovschi ◽  
Lucian Mandrea
Keyword(s):  
Experimental Approach ◽  
Similarity Criterion ◽  
Laboratory Model ◽  
Fish Ladder ◽  
Vertical Slot ◽  
Different Types ◽  
Experimental Laboratory ◽  
Model Size ◽  
Submerged Orifice ◽  
Power Densities

The paper presents the hydraulic experimental results from different types of fish ladders heaving pools and baffles with submerged orifice or vertical slot. The goal of the experiments is to develop a database of velocities and power densities for each type of fish ladder with the baffles in different arrangements, for different lengths of the pools. So, based on the fish ladder type, the hydraulic characteristic database and the experimental laboratory model size provided by this study, one can improve the design of a fish ladder. The laboratory experimental model is designed with respect to Froude similarity criterion.

Experimental Approach to the Hydraulics of Vertical Slot Fishways

2004 ◽  
Vol 130 (1) ◽  
pp. 10-23 ◽  
Author(s):  
J. Puertas ◽  
L. Pena ◽  
T. Teijeiro
Keyword(s):  
Experimental Approach ◽  
Vertical Slot

Analysis and Design of Offshore Pile Foundation

2014 ◽  
Vol 891-892 ◽  
pp. 17-23 ◽  
Author(s):  
Sudip Basack
Keyword(s):  
Pile Foundation ◽  
Complex Loading ◽  
Offshore Structures ◽  
Laboratory Model ◽  
Element Analysis ◽  
Analysis And Design ◽  
Theoretical Investigations ◽  
Experimental Laboratory ◽  
Combined Action ◽  
Ocean Environment

The ocean environment necessitates the pile foundation supporting the offshore structures to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition induces progressive degradation in the pile-soil interactive performance introducing significant reduction in bearing capacity with increased settlement and displacements. The Author has carried out extensive experimental (laboratory model tests) and theoretical investigations (boundary element analysis) to study the salient features of this degradation and developed a design methodology for offshore pile foundation. The works conducted and the major conclusions drawn are highlighted in this paper.

Clarifying the Carbon Nanotube Actuation Mechanism: An Experimental Approach

2012 ◽  
Author(s):  
Sebastian M. Geier ◽  
Stephan Müller ◽  
Thorsten Mahrholz ◽  
Peter Wierach ◽  
Johannes Riemenschneider ◽  
...  
Keyword(s):  
Experimental Approach ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Actuation Mechanism ◽  
Different Types ◽  
Out Of Plane ◽  
Vertically Aligned ◽  
Free Strain ◽  
Single Walled Cnts ◽  
Walled Cnts

Experimental investigations of different architectures made of pure, as produced carbon nanotubes (CNTs) are the main focus of this presented article. Different types of experimental setups are used to analyze the free strain of the CNT-based architectures. According to their build-up different experimental setups like actuated tensile tests, in-plane and out-of-plane strain measurements are realized to investigate the actuation mechanism and possible dependencies. The first analyzed architecture can be characterized as a 2D paper of randomly oriented, entangled single walled CNTs, also called Bucky-paper. In contrast the second investigated architecture consists of highly oriented, vertically aligned multi walled CNTs grown on a substrate of glassy carbon. The results are evaluated according to findings of various other material quality tests in order to find a significant statement for their possible actuation mechanisms.

scholarly journals Reynolds shear-stress and velocity: positive biological response of neotropical fishes to hydraulic parameters in a vertical slot fishway

2012 ◽  
Vol 10 (4) ◽  
pp. 813-819 ◽  
Author(s):  
Bernardo Alan de Freitas Duarte ◽  
Isabella Cristina Resende Ramos ◽  
Hersília de Andrade e Santos
Keyword(s):  
Shear Stress ◽  
Fish Species ◽  
Velocity Fluctuation ◽  
Reynolds Shear Stress ◽  
Neotropical Fishes ◽  
Fish Ladder ◽  
Vertical Slot ◽  
Structure Of Flow ◽  
Vertical Slot Fishway ◽  
Pimelodus Maculatus

The barriers created by dams can cause negative impacts to aquatic communities, and migratory fish species are directly affected. Fishways have been developed to allow the upstream passage of fishes through dams. In Brazil, after the implementation of environmental laws, these structures have been built based on European and American fishway designs. Studies have shown selectivity for different neotropical fishes in some Brazilian fishways, and the main challenge has been to promote upstream passage of a large number of diverse fish species. The patterns of flow circulation within the fish ladder may explain fish selectivity although few studies detail the fish response to hydraulic characteristics of fish ladder flow. This paper presents a laboratory study, where a vertical slot fishway was built in a hydraulic flume and the behavior of two neotropical fish species (Leporinus reinhardti and Pimelodus maculatus) were analyzed. The structure of flow was expressed in terms of mean velocity, Reynolds shear-stress and velocity fluctuation fields. The individuals of Leporinus reinhardti had higher passage success than Pimelodus maculatus in the laboratory flume. Both species preferred areas of low to zero Reynolds shear-stress values. In addition, different preferences were observed for these species concerning the horizontal components of velocity fluctuation.

Pool-orifice and pool-orifice-weir fishways

1989 ◽  
Vol 16 (5) ◽  
pp. 774-777 ◽  
Author(s):  
N. Rajaratnam ◽  
C. Katopodis ◽  
A. Mainali
Keyword(s):  
Open Channel ◽  
Open Channel Flow ◽  
Technical Note ◽  
Total Flow ◽  
Total Flow Rate ◽  
Vertical Slot ◽  
Flow Hydraulics ◽  
Orifice Flow ◽  
Flow Through ◽  
Submerged Orifice

This technical note presents a method of analyzing the flow in pool-orifice fishways by dividing it into vertical slot and submerged orifice flow regimes. For a pool-orifice-weir fishway, with flow through the orifice as well as over the weir, a method has been suggested for predicting the total flow rate in the fishway. Experimental observations are presented in support of these methods. Key words: open-channel flow, hydraulics, fishways, turbulent flow.

scholarly journals The three-spined stickleback-Schistocephalus solidussystem: an experimental model for investigating host-parasite interactions in fish

Parasitology ◽  
2009 ◽  
Vol 137 (3) ◽  
pp. 411-424 ◽  
Author(s):  
I. BARBER ◽  
J. P. SCHARSACK
Keyword(s):  
Immune Responses ◽  
Gasterosteus Aculeatus ◽  
Laboratory Model ◽  
Host Fish ◽  
Schistocephalus Solidus ◽  
Host Parasite Interactions ◽  
Experimental Laboratory ◽  
Host Parasite ◽  
Host Behaviour

SUMMARYPlerocercoids of the pseudophyllidean cestodeSchistocephalus solidusinfect the three-spined sticklebackGasterosteus aculeatus, with important consequences for the biology of host fish. Techniques for culturing the parasitein vitroand generating infective stages that can be used to infect sticklebacks experimentally have been developed, and the system is increasingly used as a laboratory model for investigating aspects of host-parasite interactions. Recent experimental laboratory studies have focused on the immune responses of hosts to infection, the consequences of infection for the growth and reproductive development of host fish and the effects of infection on host behaviour. Here we introduce the host and the parasite, review the major findings of these recent experimental infection studies and identify further aspects of host parasite interactions that might be investigated using the system.

scholarly journals Research on Design and Method to Predict Fatigue Life of an Anti-Vibration Mount

2019 ◽  
Vol 8 (6S) ◽  
pp. 540-544
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Experimental Approach ◽  
Crack Nucleation ◽  
Functional Requirements ◽  
Linear Effect ◽  
Growth Mechanics ◽  
Different Types ◽  
Machine Parts ◽  
Almost All

In Industry almost all the machinery are subjected to noise, shocks and vibrations when machines are working. These vibrations leads to more frequent repairs and replacements of machine parts also reduce their life span. Antivibration mount is used as a Vibration Control Solutions for machineries. This work is more focused on the importance of anti-vibration mount, which can be used for various mechanical system. This study includes the design of mounts for various functional requirements and fatigue life prediction methods. There are several approaches to predict the fatigue life of mount. Initially, different types of failures in anti-vibration mounts are discussed in detail. Analytical method, Finite Element Method and Experimental approach to predict the fatigue life are analyzed. The strain life approach is considered, incorporate with material properties of mount and another approaches were discussed that are harmonic response, crack nucleation and crack growth mechanics. It is conclude with, the strain life approach is convenient method to predict the fatigue life of antivibration mount, because it give highly non-linear effect to find the critical region of mount

scholarly journals Behaviours indicating cannibalistic necrophagy in ants are modulated by the perception of pathogen infection level

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
István Maák ◽  
Eszter Tóth ◽  
Magdalena Lenda ◽  
Gábor Lőrinczi ◽  
Anett Kiss ◽  
...  
Keyword(s):  
Food Sources ◽  
Infection Level ◽  
Additional Food ◽  
Hygienic Behaviour ◽  
Formica Polyctena ◽  
Rapid Spread ◽  
Different Types ◽  
Experimental Laboratory ◽  
Different Levels ◽  
Behavioural Adaptations

Abstract Cannibalistic necrophagy is rarely observed in social hymenopterans, although a lack of food could easily favour such behaviour. One of the main supposed reasons for the rarity of necrophagy is that eating of nestmate corpses carries the risk of rapid spread of pathogens or parasites. Here we present an experimental laboratory study on behaviour indicating consumption of nestmate corpses in the ant Formica polyctena. We examined whether starvation and the fungal infection level of the corpses affects the occurrence of cannibalistic necrophagy. Our results showed that the ants distinguished between corpses of different types and with different levels of infection risk, adjusting their behaviour accordingly. The frequency of behaviours indicating cannibalistic necrophagy increased during starvation, although these behaviours seem to be fairly common in F. polyctena even in the presence of other food sources. The occurrence and significance of cannibalistic necrophagy deserve further research because, in addition to providing additional food, it may be part of the hygienic behaviour repertoire. The ability to detect infections and handle pathogens are important behavioural adaptations for social insects, crucial for the fitness of both individual workers and the entire colony.

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