scholarly journals Conditions for stability of the “vessel-purse seine” system during purse seining

2021 ◽  
Vol 937 (3) ◽  
pp. 032058
Author(s):  
A V Ivanovskaya ◽  
E V Bogatyreva
Keyword(s):  
Mathematical Model ◽  
Purse Seine ◽  
Tension Force ◽  
Hydrodynamic Resistance ◽  
Geometrical Parameters ◽  
Fishing Vessel ◽  
The Relationship ◽  
Improve Stability ◽  
Purse Seining

Abstract In the process of tightening the rings of the lower seine line, significant forces of hydrodynamic resistance of the netting can capsize the vessel or pull it into the encircled seine area. There is a risk of damage to the propeller-rudder system of the vessel. The list and trim of a fishing vessel can occur. It affects the safety and comfort of the crew, leads to malfunctions of fishing equipment and mechanisms, and can cause accidents. During the vessel’s operation, there are a number of measures to improve stability. However, when designing fishing equipment, it is necessary to know the forces acting from the seine side on the vessel. The article discusses the relationship between the vessel and the seine during purse seining. On the basis of the developed mathematical model of the tension force of the purse rope, taking into account the geometrical parameters of the warp during purse seining, conditions for stability of the “vessel-purse seine” system were obtained.

scholarly journals Estimation of the stability of a fishing vessel during purse seining

2021 ◽  
Vol 937 (3) ◽  
pp. 032057
Author(s):  
A V Ivanovskaya ◽  
E V Bogatyreva
Keyword(s):  
Three Dimensional ◽  
Static Stability ◽  
Tension Force ◽  
Geometrical Parameters ◽  
Dimensional Representation ◽  
Fishing Vessel ◽  
Three Dimensional Representation ◽  
The Stability ◽  
Improve Stability ◽  
Purse Seining

Abstract One of the reasons for the emergency of a fishing vessel, as well as for the failure of fishing equipment, is the sudden tension of the purse rope, which occurs when the fishing equipment is pulled. As a result of the loss of stability the vessel may enter the encircled seine area and even capsize. There are a number of measures to improve stability during the operation of the vessel. However, when designing fishing equipment, it is necessary to know forces acting on the vessel from the seine side. The article presents a method for assessing the static stability of a vessel with a static application of the tension force of the purse rope. As a result of the study, an expression for determining the static heel angle using a three-dimensional representation of the vessel is given. During simulation the geometrical parameters of the purse rope in the process of purse seine were taken into account. The tension force of the purse rope is also presented as a variable.

scholarly journals HUBUNGAN UKURAN DAN KEMAMPUAN MUAT KAPAL PUKAT CINCIN KECIL PADA BEBERAPA DAERAH DI SULAWESI UTARA

2013 ◽  
Vol 9 (1) ◽  
pp. 31
Author(s):  
Revols DCh Pamikiran
Keyword(s):  
Mathematical Model ◽  
Load Capacity ◽  
Pelagic Fish ◽  
Loading Capacity ◽  
Fishing Vessel ◽  
Small Pelagic Fish ◽  
North Sulawesi ◽  
The Relationship

Kapal pukat cincin kecil merupakan kapal ikan yang umum digunakan untuk menangkap ikan pelagis kecil pada beberapa lokasi perairan di Sulawesi Utara. Penelitian ini bertujuan untuk mengetahui hubungan antara sesama dimensi ukuran utama dan antara dimensi ukuran utama dengan kemampuan muat pada 41 sampel kapal pukat cincin yang tersebar di beberapa lokasi di Sulawesi Utara. Hasil penelitian menunjukkan bahwa antara dimensi utama kapal pukat cincin memiliki model persamaan B=1,855+1,149L dengan r=0,74; D=-3,817+9,277L dengan r=0,70, dan hubungan antara panjang (L) dan kapasitas muat (GT) kapal pukat cincin menuruti model persamaan GT pukat cincin=2,154L0,043L dengan r=0,95. Kata kunci: muatan kotor, kapal pukat cincin, Sulawesi Utara.   Small Purse-Seiner is a fishing vessel which is commonly used in catching small pelagic fish in several locations in North Sulawesi. The purpose of this study was to determine the relationship between the principle dimensions and between principle dimension with loading capacity (Gross Tonnage, GT).  This research was conducted on 41 purse seiners from several locations in North Sulawesi. The results showed that relationship bet­ween the principle dimensions followed the equation models B=1.855+1.149L, with r=0.74; D=-3.817+9.277L, with r=0.70, and the relationship between the length (L) and load capacity (GT) purse seiner is fitted by the following mathematical model: GT purse seiner=2.154L0.043L with r=0.95. Keywords: gross tonnage, small purse-seiner, North Sulawesi.

scholarly journals Fishing on Porpoise

2021 ◽  
Vol 98 (1) ◽  
pp. 56-82
Author(s):  
M. Blake Butler
Keyword(s):  
Yellowfin Tuna ◽  
Purse Seine ◽  
The Future ◽  
Technological Developments ◽  
Tuna Industry ◽  
Live Bait ◽  
The Relationship ◽  
Purse Seining

Since the late 1950s, millions of dolphins have died as bycatch in the American yellowfin tuna industry. These deaths were not caused by accidental incidents between humans and dolphins, but rather were the result of a common fishing method used to catch yellowfin tuna that fishermen called “porpoise fishing” or “fishing on porpoise.” Although fishermen had caught tuna alongside dolphins since the 1930s, mass dolphin bycatch did not begin until the late 1950s, when the fleet converted from live-bait pole-and-line fishing to purse seining. This conversion—labeled the “purse-seine revolution”—occurred in response to economic and geopolitical pressures that threatened the future of the industry and was made possible by technological advancements that made purse seining a more effective method for catching yellowfin tuna. This conversion fundamentally altered the relationship between fishermen and dolphins. This article argues that the origins of mass dolphin bycatch are rooted in the purse-seine revolution and lie in the nexus of the economic, geopolitical, and technological developments that led to this conversion.

KEUNTUNGAN DAN RISIKO USAHA MINI PURSE SEINE DI DESA SATHEAN

2017 ◽  
Vol 1 (2) ◽  
pp. 49-57
Author(s):  
Frischilla Pentury ◽  
Eygner Gerald Talakua ◽  
Tati Ngangun
Keyword(s):  
Business Owners ◽  
Purse Seine ◽  
Primary Data ◽  
Business Risk ◽  
New Paradigm ◽  
Risk Calculation ◽  
Business Sustainability ◽  
Profit Analysis ◽  
Business Profit ◽  
The Relationship

The low profits of mini purse seine in Sathean Village will have an impact on the business risks being carried out. The new paradigm states that the relationship between risk and profit levels is quadratic; too much risk can lead to the loss and even destruction of a business. Thus, the fisherman of mini purse seine business owners in Sathean Village needs to manage their business risk well to achieve optimum profit for business sustainability. This study aims to assess business profits and business risks. Primary data was collected on 6 fisherman owners of mini purse seine business owners in Sathean Village as respondents, conducted business profit analysis and business risk calculation based on probability density. The results showed that the business profit was Rp 241,608,203/year or Rp 196,551,994 in the peak season, Rp 41.828.721 in the medium season and Rp 3.2227.488 in the less season.In peak and less seasons, these businesses are at risk or have the opportunity to lose, while in the medium season is not risky.

MODELING OF THE DYNAMIC PROCESS RELEASE OF STUCK DRILLING TOOLS BY HYDRO-PULSE METHOD

2019 ◽  
pp. 94-103
Author(s):  
K. H. Levchyk ◽  
M. V. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Dynamic Process ◽  
Drilling Fluid ◽  
Pulse Method ◽  
Geometrical Parameters ◽  
Technical Solution ◽  
Rock Layer ◽  
Drilling Tool ◽  
Drilling Tools ◽  
Drill Pipes

A technical solution is proposed for the elimination the grabbing of drilling tool, based on the use of energy due to the circulation of the drilling fluid. The expediency eliminating the grabbing drilling tool using the hydro-impulse method is substantiated. A method of drawing up a mathematical model for the dynamic process of a grabbing string of drill pipes in the case of perturbation of hydro-impulse oscillations in the area of the productive rock layer is developed. The law of longitudinal displacements arising in the trapped string is obtained, which allows choosing the optimal geometrical parameters of the passage channels and the frequency rotational of shutter for these channels. Recommendations for using this method for practical use have been systematized.

Temperature Influence on Performance of Oxidation Ponds

1991 ◽  
Vol 24 (5) ◽  
pp. 85-96 ◽  
Author(s):  
Qingliang Zhao ◽  
Zijie Zhang
Keyword(s):  
Mathematical Model ◽  
Temperature Influence ◽  
Field Scale ◽  
Experiment Data ◽  
Computer Technique ◽  
Oxidation Pond ◽  
Optimum Model ◽  
Oxidation Ponds ◽  
The Mathematical Model ◽  
The Relationship

By means of simulated tests of a laboratory–scale oxidation pond model, the relationship between BOD5 and temperature fluctuation was researched. Mathematical modelling for the pond's performance and K1determination were systematically described. The calculation of T–K1–CeCe/Ci) was complex but the problem was solved by utilizing computer technique in the paper, and the mathematical model which could best simulate experiment data was developed. On the basis of experiment results,the concept of plug–ratio–coefficient is also presented. Finally the optimum model recommended here was verified with the field–scale pond data.

Pulse-Width Modulated Amplifier for DC Servo System and Its Matlab Simulation

2015 ◽  
Vol 9 (1) ◽  
pp. 625-631
Author(s):  
Ma Xiaocheng ◽  
Zhang Haotian ◽  
Cheng Yiqing ◽  
Zhu Lina ◽  
Wu Dan
Keyword(s):  
Mathematical Model ◽  
Transfer Function ◽  
Input Signal ◽  
Pulse Width ◽  
Rotation Speed ◽  
Servo Motor ◽  
Matlab Simulation ◽  
Pulse Width Modulated ◽  
Signal Changes ◽  
The Relationship

This paper introduces a mathematical model for Pulse-Width Modulated Amplifier for DC Servo Motor. The relationship between pulse-width modulated (PWM) signal and reference rotation speed is specified, and a general model of motor represented by transfer function is also put forward. When the input signal changes, the rotation speed of the servo motor will change accordingly. By changing zeros and poles, transient performance of this system is discussed in detail, and optimal ranges of the parameters is recommended at the end of discussion.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

scholarly journals Theoretical Modeling, Design and Simulation of an Innovative Diverting Valve Based on Coanda Effect

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 103
Author(s):  
Giancarlo Comes ◽  
Carlo Cravero
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Additive Manufacturing ◽  
Water Flow ◽  
Coanda Effect ◽  
Geometrical Parameters ◽  
Convex Wall ◽  
Fluidic Device ◽  
Coandǎ Effect

The present work is focused on the study of an innovative fluidic device. It consists of a two-ways diverter valve able to elaborate an inlet water flow and divert it through one of the two outlets without moving parts but as a result of a fluctuation of pressure induced by two actuation ports, or channels. Such apparatus is named Attachment Bi-Stable Diverter (ABD) and is able to work with the effect of the fluid adhesion to a convex wall adjacent to it, this phenomenon is known as Coanda Effect; it generates the force responsible for the fluid attachment and the consequent deviation. The main purpose of this work is to develop a knowhow for the design and development of such particular device. A mathematical model for the ABD has been developed and used to find the relationships between the geometrical parameters and the operative conditions. A configuration has been designed, simulated with a computational fluid dynamics approach. A prototype has been printed with and additive manufacturing printer and tested in laboratory to check the effective working point of the device.

A MATHEMATICAL MODEL OF THE PHYSICAL GROWTH MECHANISM AND GEOMETRICAL CHARACTERIZATION OF GROWING FORMS

2011 ◽  
Vol 04 (01) ◽  
pp. 35-53 ◽  
Author(s):  
YURI K. SHESTOPALOFF
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Growth Mechanism ◽  
Growth Suppression ◽  
Physical Growth ◽  
Geometrical Parameters ◽  
Growth Equation ◽  
Software Application ◽  
Multicellular Organisms

The article introduces a mathematical model of the physical growth mechanism which is based on the relationships of the physical and geometrical parameters of the growing object, in particular its surface and volume. This growth mechanism works in cooperation with the biochemical and other growth factors. We use the growth equation, which mathematically describes this mechanism, and study its adequacy to real growth phenomena. The growth model very accurately fits experimental data on growth of Amoeba, Schizosaccharomyces pombe, E.coli. Study discovered a new growth suppression mechanism created by certain geometry of the growing object. This result was proved by experimental data. The existence of the growth suppression phenomenon confirms the real workings and universality of the growth mechanism and the adequacy of its mathematical description. The introduced equation is also applicable to the growth of multicellular organisms and tumors. Another important result is that the growth equation introduces mathematical characterization of geometrical forms that can biologically grow. The material is supported by software application, which is released to public domain.

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