scholarly journals Kinematic and Dynamic Scaling of Copepod Swimming

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 68
Author(s):  
Leonid Svetlichny ◽  
Poul S. Larsen ◽  
Thomas Kiørboe
Keyword(s):  
Direct Measurement ◽  
Swimming Speed ◽  
Beat Frequency ◽  
Power Production ◽  
Dynamic Scaling ◽  
Calanoid Copepods ◽  
Prosome Length ◽  
Transportation Mode ◽  
The Cost ◽  
Cost Of Transportation

Calanoid copepods have two swimming gaits, namely cruise swimming that is propelled by the beating of the cephalic feeding appendages and short-lasting jumps that are propelled by the power strokes of the four or five pairs of thoracal swimming legs. The latter may be 100 times faster than the former, and the required forces and power production are consequently much larger. Here, we estimated the magnitude and size scaling of swimming speed, leg beat frequency, forces, power requirements, and energetics of these two propulsion modes. We used data from the literature together with new data to estimate forces by two different approaches in 37 species of calanoid copepods: the direct measurement of forces produced by copepods attached to a tensiometer and the indirect estimation of forces from swimming speed or acceleration in combination with experimentally estimated drag coefficients. Depending on the approach, we found that the propulsive forces, both for cruise swimming and escape jumps, scaled with prosome length (L) to a power between 2 and 3. We further found that power requirements scales for both type of swimming as L3. Finally, we found that the cost of transportation (i.e., calories per unit body mass and distance transported) was higher for swimming-by-jumping than for cruise swimming by a factor of 7 for large copepods but only a factor of 3 for small ones. This may explain why only small cyclopoid copepods can afford this hydrodynamically stealthy transportation mode as their routine, while large copepods are cruise swimmers.

OPTIMAL FEASIBLE SOLUTIONS TO A ROAD FREIGHT TRANSPORTATION PROBLEM

2020 ◽  
Vol 5 (1) ◽  
pp. 456
Author(s):  
Tolulope Latunde ◽  
Joseph Oluwaseun Richard ◽  
Opeyemi Odunayo Esan ◽  
Damilola Deborah Dare
Keyword(s):  
Transportation Problem ◽  
Optimal Solution ◽  
Transportation Cost ◽  
North West ◽  
Life Problems ◽  
Basic Feasible Solutions ◽  
Feasible Solutions ◽  
Road Freight Transportation ◽  
The Cost ◽  
Cost Of Transportation

For twenty decades, there is a visible ever forward advancement in the technology of mobility, vehicles and transportation system in general. However, there is no "cure-all" remedy ideal enough to solve all life problems but mathematics has proven that if the problem can be determined, it is most likely solvable. New methods and applications will keep coming to making sure that life problems will be solved faster and easier. This study is to adopt a mathematical transportation problem in the Coca-Cola company aiming to help the logistics department manager of the Asejire and Ikeja plant to decide on how to distribute demand by the customers and at the same time, minimize the cost of transportation. Here, different algorithms are used and compared to generate an optimal solution, namely; North West Corner Method (NWC), Least Cost Method (LCM) and Vogel’s Approximation Method (VAM). The transportation model type in this work is the Linear Programming as the problems are represented in tables and results are compared with the result obtained on Maple 18 software. The study shows various ways in which the initial basic feasible solutions to the problem can be obtained where the best method that saves the highest percentage of transportation cost with for this problem is the NWC. The NWC produces the optimal transportation cost which is 517,040 units.

IMPROVING THE RELIABILITY OF TRAILED DUMP VEHICLES

2021 ◽  
Vol 2 (21) ◽  
pp. 89-96
Author(s):  
E.V. Ibragimov ◽  
Keyword(s):  
Automotive Industry ◽  
Structural Strength ◽  
Operational Reliability ◽  
Technical Solution ◽  
Industrial Complex ◽  
Quality And Safety ◽  
The Russian Federation ◽  
Cargo Transportation ◽  
The Cost ◽  
Cost Of Transportation

Increasing the productivity and efficiency of agricultural cargo transportation in the agro-industrial complex of the Russian Federation is achieved through the use of tractor trains consist-ing of tractors and trailer links, the main of which are trailers. This method allows you to ensure the quality and safety of agricultural goods, as well as reduce the cost of transportation. During the analysis of the known designs of tractor-trailer dump trailers, it was revealed that a character-istic drawback is the imperfection of the design of the locking elements of the platforms designed to fix them on the chassis. As a result, a promising technical solution was developed, which, in comparison with the known ones, has a simple design and increased efficiency when fixing the bodies on the chassis. The article describes the design and the principle of operation of this tech-nical solution. The results of the structural strength calculation are presented. The conducted check showed that the obtained value of the safety factor, equal to 2.2, will ensure the operational reliability of trailed dump vehicles. The results of the study are recommended to both domestic and foreign research institutes, design and production structures of the automotive industry for further study and refinement of the proposed device with a view to its possible implementation in practice.

THE EFFECT OF SOLID AND POROUS CHANNEL WALLS ON STEADY SWIMMING OF STEELHEAD TROUT ONCORHYNCHUS MYKISS

1993 ◽  
Vol 178 (1) ◽  
pp. 97-108 ◽  
Author(s):  
P. W. Webb
Keyword(s):  
Swimming Speed ◽  
Swimming Performance ◽  
Beat Frequency ◽  
Regression Coefficients ◽  
Steelhead Trout ◽  
Wall Effects ◽  
Fish Swimming ◽  
Wide Channel ◽  
Solid Walls ◽  
Tail Beat

Kinematics and steady swimming performance were recorded for steelhead trout (approximately 12.2 cm in total length) swimming in channels 4.5, 3 and 1.6 cm wide in the centre of a flume 15 cm wide. Channel walls were solid or porous. Tail-beat depth and the length of the propulsive wave were not affected by spacing of either solid or porous walls. The product of tail-beat frequency, F, and amplitude, H, was related to swimming speed, u, and to harmonic mean distance of the tail from the wall, z. For solid walls: FH = 1.01(+/−0.31)u0.67(+/−0.09)z(0.12+/−0.02) and for grid walls: FH = 0.873(+/−0.302)u0.74(+/−0.08)z0.064(+/−0.024), where +/−2 s.e. are shown for regression coefficients. Thus, rates of working were smaller for fish swimming between solid walls, but the reduction due to wall effects decreased with increasing swimming speed. Porous grid walls had less effect on kinematics, except at low swimming speeds. Spacing of solid walls did not affect maximum tail-beat frequency, but maximum tail-beat amplitude decreased with smaller wall widths. Maximum tail-beat amplitude similarly decreased with spacing between grid walls, but maximum tail-beat frequency increased. Walls also reduced maximum swimming speed. Wall effects have not been adequately taken into account in most studies of fish swimming in flumes and fish wheels.

The Kinematics of Swimming in Larvae of the Clawed Frog, Xenopus Laevis

1986 ◽  
Vol 122 (1) ◽  
pp. 1-12 ◽  
Author(s):  
KARIN VON SECKENDORFF HOFF ◽  
RICHARD JOEL WASSERSUG
Keyword(s):  
Xenopus Laevis ◽  
Swimming Speed ◽  
High Speed ◽  
Total Mass ◽  
Beat Frequency ◽  
Maximum Amplitude ◽  
Open Water ◽  
Computer Assisted ◽  
Anuran Larvae ◽  
Tail Beat

The kinematics of swimming in larval Xenopus laevis has been studied using computer-assisted analysis of high-speed (200 frames s−1) ciné records. The major findings are as follows. 1. At speeds below 6 body lengths (L) per second, tail beat frequency is approximately 10 Hz and, unlike for most aquatic vertebrates, is not correlated with specific swimming speed. At higher speeds, tail beat frequency and speed are positively correlated. 2. Xenopus tadpoles show an increase in the maximum amplitude of the tail beat with increasing velocity up to approximately 6Ls−1. Above that speed amplitude approaches an asymptote at 20 % of body length. 3. Anterior yaw is absent at velocities below 6Ls−1, unlike for other anuran larvae, but is present at higher speeds. 4. At speeds below 6Ls−1 there is a positive linear relationship between length of the propulsive wave (λ) and specific swimming speed. At higher speeds wavelength is constant at approximately 0.8L. 5. There is a shift in the modulation of wavelength and tail beat frequency with swimming speed around 5.6Ls−1, suggesting two different swimming modes. The slower mode is used during open water cruising and suspension feeding. The faster, sprinting mode may be used to avoid predators. 6. Froude efficiencies are similar to those reported for fishes and other anuran larvae. 7. Unlike Rana and Bufo larvae, the axial muscle mass of Xenopus increases dramatically with size from less than 10% of total mass for the smallest animals to more than 45% of total mass for the largest animals. This increase is consistent with maintaining high locomotor performance throughout development.

Thermodynamic Analysis of Intercooled Gas-Steam Combined and Steam Injected Gas Turbine Power Plants

2004 ◽  
Author(s):  
R. Yadav ◽  
Sunil Kumar Jumhare ◽  
Pradeep Kumar ◽  
Samir Saraswati
Keyword(s):  
Beneficial Effect ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Power Production ◽  
Specific Work ◽  
Surface Type ◽  
The Cost ◽  
Current Emphasis ◽  
Plant Efficiency

The current emphasis on the development of gas turbine related power plants such as combined and steam injected is on increasing the plant efficiency and specific work while minimizing the cost of power production per kW and emission. The present work deals with the thermodynamic analysis of intercooled (both surface and evaporative) gas/steam combined and steam injected cycle power plants. The intercooling has a beneficial effect on both plant efficiency and specific work if the optimum intercooling pressure is chosen between 3 and 4. The evaporative intercooler is superior to surface type with reference to plant efficiency and specific work.

scholarly journals Illicit Trade in Russian Gold and Silver Coins in West China in 1850's (based on the Materials of the Russian Consul K. A. Skachkov)

2020 ◽  
Vol 22 (1) ◽  
pp. 88-97
Author(s):  
I. R. Hamzin
Keyword(s):  
Historical Analysis ◽  
West China ◽  
Illicit Trade ◽  
Russian State ◽  
Trading Activities ◽  
The Government ◽  
Chinese Trade ◽  
State Library ◽  
The Cost ◽  
Cost Of Transportation

The present research featured the illicit trade in Russian gold and silver coins in Xinjiang in the 1850's. The paper focuses on the problems of control and customs services, as well as on the difficulties connected with the trade in Russian goods. The historical analysis was based on the documents written by Konstantin Adrianovich Skachkov, the then Russian Consul in Chuguchak. The materials were obtained from the Research Department of Manuscripts of the Russian State Library. In his report, Consul K. A. Skachkov compared the state of the markets of the Russian-Chinese trade in Chuguchak and Kyakhta. He highlighted the broad prospects for trade development in Xinjiang. The Consul paid great attention to the problems on the young market of Central Asia and proposed some measures to improve the situation. He performed a comparative analysis of the trading activities of a Russian merchant and a smuggler. The analysis makes it possible to reconstruct the trading process, determine the cost of transportation, and formulate the commercial benefit resulting from the legal trade and the contraband trade. K. A. Skachkov concluded that despite the high potential for trade development, the region was torn apart by substantial internal contradictions and demanded greater attention from the government. The illicit trade in Russian coins was caused by the barter trading on the Xinjiang market in 1850's.

scholarly journals A Comparison of Three Ridesharing Cost Savings Allocation Schemes Based on the Number of Acceptable Shared Rides

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6931
Author(s):  
Fu-Shiung Hsieh
Keyword(s):  
Air Pollution ◽  
Cost Saving ◽  
Comparative Study ◽  
Cost Savings ◽  
Research Community ◽  
Transportation Mode ◽  
Strong Incentive ◽  
Shared Mobility ◽  
Develop Theory ◽  
The Cost

Shared mobility based on cars refers to a transportation mode in which travelers/drivers share vehicles to reduce the cost of the journey, emissions, air pollution and parking demands. Cost savings provide a strong incentive for the shared mobility mode. As cost savings are due to cooperation of the stakeholders in shared mobility systems, they should be properly divided and allocated to relevant participants. Improper allocation of cost savings will lead to dissatisfaction of drivers/passengers and hinder acceptance of the shared mobility mode. In practice, several schemes based on proportional methods to allocate cost savings have been proposed in shared mobility systems. However, there is neither a guideline for selecting these proportional methods nor a comparative study on effectiveness of these proportional methods. Although shared mobility has attracted much attention in the research community, there is still a lack of study of the influence of cost saving allocation schemes on performance of shared mobility systems. Motivated by deficiencies of existing studies, this paper aims to compare three proportional cost savings allocation schemes by analyzing their performance in terms of the numbers of acceptable rides under different schemes. We focus on ridesharing based on cars in this study. The main contribution is to develop theory based on our analysis to characterize the performance under different schemes to provide a guideline for selecting these proportional methods. The theory developed is verified by conducting experiments based on real geographical data.

scholarly journals ESTIMATED TRANSPORTATION COST OF LOW-TONNAGE LNG

2020 ◽  
Vol 17 (5) ◽  
pp. 130-163
Author(s):  
O. V. Tarovik ◽  
O. M. Mudrova
Keyword(s):  
Coastal Waters ◽  
Unit Cost ◽  
Transportation Cost ◽  
Model Calculations ◽  
Inland Waterways ◽  
Universal Approach ◽  
Environmental Requirements ◽  
Regression Relations ◽  
The Cost ◽  
Cost Of Transportation

Demand for low-tonnage transportation of LNG requires improved logistics. Assessing the value of all parts of the supply chain is an important component of solving the problem of optimizing transportation costs for both consumers and LNG suppliers. In connection with tightening of environmental requirements regarding bunker fuel, the task of optimizing the supply of LNG for water transport by the cost of transportation becomes particularly relevant.The objective of the study is to develop a universal approach to estimating the cost of transporting low-tonnage LNG for bunkering vessels in the Russian Federation.The research methodology is focused on the analytical method based on a system-structural approach.As part of the departmental project of the Russian Ministry of Industry and Trade «Development of  gaspowered fleet for navigation in coastal waters and inland waterways», the authors developed technical and economic models for calculating the unit cost of LNG transportation by road and water. To calculate the unit cost of LNG transportation by rail, the data of TMkarta information and reference system were used. Based on model calculations and data of TMkarta system, regression relations were obtained that allow one to determine the cost of transportation for various options of transport and technological schemes based on a limited set of parameters. An approach has also been proposed for estimating the cost of LNG transshipment. The regression ratios were tested for selected routes. As a result,conclusions were drawn about the most effective LNG transportation options.

scholarly journals Clustering Control of Multi-Objective Problems with Application to E-commerce

2018 ◽  
Vol 1 (1) ◽  
pp. 41
Author(s):  
Liang Chen ◽  
Xingwei Wang ◽  
Jinwen Shi
Keyword(s):  
Ant Colony Algorithm ◽  
Time Window ◽  
Ant Colony ◽  
Distribution Area ◽  
Routing Problem ◽  
Logistics Distribution ◽  
Multi Objective ◽  
The Cost ◽  
Vehicle Capacity ◽  
Cost Of Transportation

In the existing logistics distribution methods, the demand of customers is not considered. The goal of these methods is to maximize the vehicle capacity, which leads to the total distance of vehicles to be too long, the need for large numbers of vehicles and high transportation costs. To address these problems, a method of multi-objective clustering of logistics distribution route based on hybrid ant colony algorithm is proposed in this paper. Before choosing the distribution route, the customers are assigned to the unknown types according to a lot of customers attributes so as to reduce the scale of the solution. The discrete point location model is applied to logistics distribution area to reduce the cost of transportation. A mathematical model of multi-objective logistics distribution routing problem is built with consideration of constraints of the capacity, transportation distance, and time window, and a hybrid ant colony algorithm is used to solve the problem. Experimental results show that, the optimized route is more desirable, which can save the cost of transportation, reduce the time loss in the process of circulation, and effectively improve the quality of logistics distribution service.

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