scholarly journals The Influence of Wind, Wave and Loading Condition on Total Resistance and Speed of the Vessel

2014 ◽  
Vol 21 (3) ◽  
pp. 61-67 ◽  
Author(s):  
Tadeusz Szelangiewicz ◽  
Bernard Wiśniewski ◽  
Katarzyna Želazny
Keyword(s):  
Wind Wave ◽  
Weather Conditions ◽  
Computer Code ◽  
Point Of View ◽  
Approximate Methods ◽  
Shipping Line ◽  
Ship Route ◽  
Weather Parameters ◽  
Very High ◽  
Ship Speed

Abstract Optimising the ship route is one of the most important tasks related to the operation of the vessel, its safety, and economic aspects of transport. Nevertheless, from a mathematical point of view, this problem has not been solved yet sufciently precisely due to very high complexity of the model to be used to describe the motion of the ship along the shipping line, and time- and space-dependent average values of statistical weather parameters recorded during ship sailing. Tat is why various approximate methods are used, which, among other procedures, utilize ship speed characteristics, having the form of very simple relations between basic dimensions of the ship and the expected speed decrease at the assumed weather parameters. Te paper presents a new method of calculating the speed decrease depending on technical and operating parameters of a given vessel. A computer code prepared based on this method is used for research on forecasting ship speed in real weather conditions.

scholarly journals Prediction Power Propulsion of the Ship at the Stage of Preliminary Design Part II: Mathematical Model Ship Power Propulsion for Service Speed Useful in the Preliminary Design

2017 ◽  
Vol 25 (4) ◽  
pp. 231-236
Author(s):  
Tadeusz Szelangiewicz ◽  
Atarzyna Żelazny
Keyword(s):  
Mathematical Model ◽  
Weather Conditions ◽  
Geometric Parameters ◽  
Design Parameters ◽  
Preliminary Design ◽  
Shipping Line ◽  
Calm Water ◽  
Weather Parameters ◽  
Important Design ◽  
Design Power

AbstractDuring the design of the ship the most important decisions are made at the stage of preliminary design. One of the most important design parameters assumed by the shipowner is its service speed in real weather conditions occurring in the shipping line. For this speed, at the stage of preliminary design, when are known only to the basic geometric parameters of the ship should be determined motor power. In practice design, power propulsion is determined with a very approximate formulas but for the speed in calm water. Only after the project contract and the signing of the contract are carried out by means of resistance and self-propulsion of model test. The paper presents a mathematical model for determining the power propulsion for the assumed operating speed. This model is dependent only on the basic geometric parameters of the hull of the ship and the weather parameters occurring in liner shipping. Also shows the results of calculations according to this model, the power propulsion for one of vessels built.

Effectiveness of Flood Protection Project Valuation Methods

2015 ◽  
Vol 10 (3) ◽  
pp. 275-289
Author(s):  
Tadeusz Liziński ◽  
Marcin Bukowski ◽  
Anna Wróblewska
Keyword(s):  
Essential Element ◽  
Weather Conditions ◽  
Point Of View ◽  
Flood Protection ◽  
Costs And Benefits ◽  
Protection Measures ◽  
Investment Projects ◽  
Market Values ◽  
Project Valuation ◽  
The Subject

Projects for flood protection are increasingly the subject of investment projects in the field of water management. This is related to the increasing frequency of worldwide threats caused by extreme weather conditions, including extremely high rainfall causing floods. Technical and nontechnical flood protection measures are also increasing in importance. In the decision-making process, it is necessary to take into account both the costs and benefits of avoiding losses, including an analysis of social benefits, whose valuation of non-market goods is an essential element. A comprehensive account of projects in the field of flood protection based on the estimated costs and benefits of the investment allows the economic efficiency from a general social point of view to be determined. Previous evaluations of the effectiveness of investment projects have mainly taken into account only categories and market values. The aim of the article is to identify the possibilities to expand the values of non-market assessments and categories formulated on the basis of the theoretical economics of the environment. 

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

scholarly journals Design and Field Validation of a Low Power Wireless Sensor Node for Structural Health Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1050
Author(s):  
Federico Zanelli ◽  
Francesco Castelli-Dezza ◽  
Davide Tarsitano ◽  
Marco Mauri ◽  
Maria Laura Bacci ◽  
...  
Keyword(s):  
Low Power ◽  
Sensor Node ◽  
Weather Conditions ◽  
Point Of View ◽  
Design Stage ◽  
Monitoring Systems ◽  
Wireless Sensor Node ◽  
Process Data ◽  
Fatigue Life Estimation ◽  
Remaining Fatigue Life

Smart monitoring systems are currently gaining more attention and are being employed in several technological areas. These devices are particularly appreciated in the structural field, where the collected data are used with purposes of real time alarm generation and remaining fatigue life estimation. Furthermore, monitoring systems allow one to take advantage of predictive maintenance logics that are nowadays essential tools for mechanical and civil structures. In this context, a smart wireless node has been designed and developed. The sensor node main tasks are to carry out accelerometric measurements, to process data on-board, and to send wirelessly synthetic information. A deep analysis of the design stage is carried out, both in terms of hardware and software development. A key role is played by energy harvesting integrated in the device, which represents a peculiar feature and it is thanks to this solution and to the adoption of low power components that the node is essentially autonomous from an energy point of view. Some prototypes have been assembled and tested in a laboratory in order to check the design features. Finally, a field test on a real structure under extreme weather conditions has been performed in order to assess the accuracy and reliability of the sensors.

scholarly journals FEBID 3D-Nanoprinting at Low Substrate Temperatures: Pushing the Speed While Keeping the Quality

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1527
Author(s):  
Jakob Hinum-Wagner ◽  
David Kuhness ◽  
Gerald Kothleitner ◽  
Robert Winkler ◽  
Harald Plank
Keyword(s):  
Volume Growth ◽  
Point Of View ◽  
High Fidelity ◽  
Direct Write ◽  
General Picture ◽  
3D Space ◽  
Design Flexibility ◽  
Substrate Temperatures ◽  
Very High ◽  
Comprehensive Discussion

High-fidelity 3D printing of nanoscale objects is an increasing relevant but challenging task. Among the few fabrication techniques, focused electron beam induced deposition (FEBID) has demonstrated its high potential due to its direct-write character, nanoscale capabilities in 3D space and a very high design flexibility. A limitation, however, is the low fabrication speed, which often restricts 3D-FEBID for the fabrication of single objects. In this study, we approach that challenge by reducing the substrate temperatures with a homemade Peltier stage and investigate the effects on Pt based 3D deposits in a temperature range of 5–30 °C. The findings reveal a volume growth rate boost up to a factor of 5.6, while the shape fidelity in 3D space is maintained. From a materials point of view, the internal nanogranular composition is practically unaffected down to 10 °C, followed by a slight grain size increase for even lower temperatures. The study is complemented by a comprehensive discussion about the growth mechanism for a more general picture. The combined findings demonstrate that FEBID on low substrate temperatures is not only much faster, but practically free of drawbacks during high fidelity 3D nanofabrication.

Optimization of Restoration Paths of Power System after Blackout

2013 ◽  
Vol 347-350 ◽  
pp. 1467-1472
Author(s):  
Wen Wei Huang ◽  
Gang Yao ◽  
Xiao Yan Qiu ◽  
Nian Liu ◽  
Guang Tang Chen
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Reactive Power ◽  
Minimum Spanning Tree ◽  
Operation Time ◽  
Combinatorial Problem ◽  
Weather Conditions ◽  
Recovery Process ◽  
Point Of View ◽  
Improved Genetic Algorithm

Optimization of restoration paths of power system after blackout is a multi-stage, multi-target, multi-variable combinatorial problem in the power system restoration. This paper presents a reasonable model and effectually method. The proposed model is considered as a typical partial minimum spanning tree problem from the mathematical point of view which considering all kinds of constraints. Improved data envelopment analysis (DEA) was used to get the weight which considering line charging reactive power, weather conditions, operation time and betweenness of transmission lines. The improved genetic algorithm method is employed to solve this problem. Finally, an example is given which proves the strategy of the line restoration can effectively handle the uncertainty of the system recovery process, to guarantee the system successfully restored after the catastrophic accidents.

Ship Drag Reduction by Microalgal Biopolymers: A Feasibility Analysis

2007 ◽  
Vol 51 (04) ◽  
pp. 326-337
Author(s):  
K. Gasljevic ◽  
E. F. Matthys
Keyword(s):  
Drag Reduction ◽  
Consumption Rate ◽  
Synthetic Polymers ◽  
Point Of View ◽  
Technical Issues ◽  
Fuel Costs ◽  
Propulsion Power ◽  
Ship Speed ◽  
In Situ Production

We have investigated the feasibility of using high-molecular-weight polysaccharides produced by marine microalgae to reduce the drag on ships and therefore to be able to reduce the needed propulsion power and fuel costs or, alternatively, to increase the ship speed. Experimental and analytical studies were used to answer four critical questions:How suitable are the biopolymers for drag reduction on ships?What is the needed polymer consumption rate at a given level of drag reduction?What is the achievable polymer production rate that can be achieved by the microalgae?What are possible modes of implementation of the proposed technology? It is seen that in situ production of biopolymers by microalgae growing on the hull may be a possible approach to polymeric ship drag reduction. Production of biopolysaccharide off the ship and even harvesting it from the ocean are other possibilities. The use of biopolymers is naturally advantageous from an environmental point of view as well. Some comparison of biopolymers and synthetic polymers is also presented. Several technical issues remain to be investigated, but the information available suggests that biopolymers may be the best additives for drag reduction on ships.

Revolving cards: A financial analysis of the credit repayment and legal implications

2021 ◽  
Vol 39 (2) ◽  
Author(s):  
Salvador Cruz Rambaud ◽  
Salvador Cruz Vargas
Keyword(s):  
Interest Rate ◽  
Credit Card ◽  
Financial Analysis ◽  
Point Of View ◽  
Excessive Amount ◽  
Nominal Interest Rate ◽  
Legal Implications ◽  
Long Duration ◽  
Very High

The framework of this paper is credit card holding by users and consumers, more specifically, the so-called revolving cards. In most cases, the true interest rate applied to a credit is much higher than its nominal interest rate. Usually, this is due to the existence of some fees to be paid by the holder, and to the process of splitting the periods of interest. However, the contracted annual interest rate of revolving cards is very high which, together with the peculiar amortization system, gives rise to an excessive amount of interests. The objective of this paper is to describe and analyze, from a legal and financial point of view, the main characteristics of the credit repayment in revolving cards. We conclude that the complete amortization of the principal needs a long duration and the payment of a high amount of interests.

scholarly journals Back to the Future: Very High-Energy Electrons (VHEEs) and Their Potential Application in Radiation Therapy

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4942
Author(s):  
Maria Grazia Ronga ◽  
Marco Cavallone ◽  
Annalisa Patriarca ◽  
Amelia Maia Leite ◽  
Pierre Loap ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Current Knowledge ◽  
High Energy ◽  
High Dose Rate ◽  
Point Of View ◽  
High Dose ◽  
Dose Rates ◽  
High Energy Electrons ◽  
Very High Energy ◽  
Very High

The development of innovative approaches that would reduce the sensitivity of healthy tissues to irradiation while maintaining the efficacy of the treatment on the tumor is of crucial importance for the progress of the efficacy of radiotherapy. Recent methodological developments and innovations, such as scanned beams, ultra-high dose rates, and very high-energy electrons, which may be simultaneously available on new accelerators, would allow for possible radiobiological advantages of very short pulses of ultra-high dose rate (FLASH) therapy for radiation therapy to be considered. In particular, very high-energy electron (VHEE) radiotherapy, in the energy range of 100 to 250 MeV, first proposed in the 2000s, would be particularly interesting both from a ballistic and biological point of view for the establishment of this new type of irradiation technique. In this review, we examine and summarize the current knowledge on VHEE radiotherapy and provide a synthesis of the studies that have been published on various experimental and simulation works. We will also consider the potential for VHEE therapy to be translated into clinical contexts.

scholarly journals Correlations between weather parameters, atmospheric hydrogen sulphide level and vitamin B12 administration to H2S exposed workers

2019 ◽  
Vol 70 (1) ◽  
pp. 6-11
Author(s):  
Livia-Cristina Borcan ◽  
Florin Borcan ◽  
Elena-Ana Păuncu ◽  
Mirela Cleopatra Tomescu
Keyword(s):  
Blood Pressure ◽  
Vitamin B12 ◽  
Hydrogen Sulphide ◽  
Prolonged Exposure ◽  
Numerical Data ◽  
Weather Conditions ◽  
Professional Exposure ◽  
Exposed Workers ◽  
Weather Parameters ◽  
One Year

Abstract Hydrogen sulphide, a highly toxic gas, can be used in crenotherapy to balance all metabolic processes (minerals, fats and proteins). The main aims of this study were to correlate the weather characteristics with the atmospheric H2S level and to evaluate the antidote activity of B12 Vitamin in the case of prolonged exposure to this compound. 46 volunteers, people from the medical staff of an important Romanian thermal water spring spa, with professional exposure at H2S, were enrolled in this study; numerical data about their blood pressure, atmospheric H2S concentration and about the weather conditions were collected every month for one year. The results indicate an improvement in the blood pressure of volunteers treated with Vitamin B12; no significant correlation between the concentration of total urinary sulphur and the concentration of atmospheric H2S level was found.

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