A Rapid tool for the stability assessment of natural food colours

During the development of new stability regulations for the U.K. Department of Transport, doubt was cast over many of the assumptions made when assessing the stability of sailing vessels. In order to investigate the traditional methods a programme of work was undertaken including wind tunnel tests and full scale data acquisition. The work resulted in a much improved understanding of the behaviour of sailing vessels and indeed indicated that the conventional methods of stability assessment are invalid, the rules now applied in the U.K. being very different to those in use elsewhere. The paper concentrates on the model test techniques which were developed specifically for this project but which will have implications to other vessel types. The tests were of two kinds: measurement of the wind forces and moments on a sailing vessel; and investigation of the response of sailing vessels to gusts of wind. For the force and moment measurements models were mounted in a tank of water on a six component balance and tested in a large boundary layer wind tunnel. Previous tests in wind tunnels have always concentrated on performance and the heeling moments have not normally been measured correctly. As the measurements of heeling moment at a range of heel angles was of prime importance a new balance and mounting system was developed which enabled the above water part of the vessel to be modelled correctly, the underwater part to be unaffected by the wind, and the interface to be correctly represented without interference. Various effects were investigated including rig type, sheeting, heading, heel angle and wind gradient. The gust response tests were conducted with Froude scaled models floating in a pond set in the wind tunnel floor. A mechanism was installed in the tunnel which enabled gusts of various characteristics to be generated, and the roll response of the models was measured with a gyroscope. These tests provided information on the effects of inertia, damping, rolling and the characteristics of the gust. Sample results are presented to illustrate the uses to which these techniques have been put.

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Сombined ships stability analysis at the stage of design study

Russian Journal of Water Transport ◽

10.37890/jwt.vi66.158 ◽

2021 ◽

pp. 29-35

Author(s):

Ilya A. Gulyaev Gulyaev ◽

Evgeniy P. Ronnov

Keyword(s):

Stability Analysis ◽

Optimization Problems ◽

Mutual Influence ◽

Static Stability ◽

Wind Effect ◽

Stability Assessment ◽

Design Study ◽

Hull Design ◽

The Stability ◽

Russian River

. A method of stability analysis for combined ship (oil carrier/platform ship type) at the stage of design study is presented. It should be noted that not all of ship’s main seaworthiness and operational characteristics are the result of a simple addition of the characteristics of an oil carrier and a platform ship. Their mutual influence takes place, which should be taken into account when analysing the stability in the multivariant optimization problems of internal and external design of such ships. This leads to the requirement to adjust the known methods of stability analysis at the initial stages of ship design, which was the purpose of the present work and its originality. Taking into account the multivariance of the task and the hull design type, the stability assessment will be carried out through the analysis of the metacentric height extreme value on the assumption that the requirements of Russian River Register for admissible heeling angle at static wind effect are met. In order to account for nonlinearity of static stability curve when inclining up to the angles of deck immersion into water and emergence of bilge, it is suggested to apply an approximate method of metacentric radius determination. The proposed method of combined ship stability assessment is recommended to apply at the stage of justification and analysis of ship’s key elements as a limitation in the problems of mathematical modeling of optimization of such type of ships. The method allows to exclude from further consideration at the design study stage the possible options that do not meet the requirements of seaworthiness.

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BALLAST WATER POLLUTION RISK ASSESSMENT IN THE BLACK SEA

Mechanical Testing and Diagnosis ◽

10.35219/mtd.2020.4.05 ◽

2021 ◽

Vol 10 (4) ◽

pp. 35-40

Author(s):

Vasile RAŢᾸ ◽

Liliana RUSU

Keyword(s):

Risk Assessment ◽

Black Sea ◽

Marine Environment ◽

Ballast Water ◽

Safety Net ◽

The Black Sea ◽

Natural Food ◽

Economic Activities ◽

Living Organisms ◽

The Stability

Since the emergence of humanity, the marine environment has provided a safety net in many ways, has fostered socio-economic development, creating links between states, between continents. In the same time, it represents a priority source of food for a considerable percentage of the population. The same marine environment also creates solutions to current global problems, as a potential source of sustainable energy for the future. In recent decades, the stability of this ecosystem has been considerably shaken by the various types of pollution resulting from human activities. The Black Sea is not immune to these results from economic activities, such as the transport of goods by water, which creates the context for the migration of living organisms from one geographical region to another. The threat of ecosystems has been intensified by the process of globalization, by changing the natural food chains following the accidental introduction of non- indigenous marine life by discharging ballast water from ship tanks. Risk assessment to limit the effects of this biohazard problem is the first step in a normal regional chain of action..

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Mid-Term Stability Assessment of Jiangxi Power Grid

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.732-733.882 ◽

2013 ◽

Vol 732-733 ◽

pp. 882-887

Author(s):

Yong Chun Su ◽

Hao Wei Jia

Keyword(s):

Power System ◽

Power Grid ◽

Assessment Method ◽

Control Measures ◽

Assessment Process ◽

Jiangxi Province ◽

Stable Operation ◽

Stability Assessment ◽

Term Stability ◽

The Stability

Mid-term stability assessment is an important work to support power system operation in a province power grid of China every year. The stability assessment method and process was introduced in this paper. As an example, the stability of Jiangxi province power system was evaluated in the following two years. Weak area and weak transmission line were found out in each power supply area. Prevention and control measures were proposed. According to problems among the assessment process and using the state monitoring data, an approach was discussed to increase the assessment result accuracy. The analysis conclusion provides the reference to the safe and stable operation of Jiangxi power system.

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The Stability Analysis of a Multi-Port Single-Phase Solid-State Transformer in the Electromagnetic Timescale

Energies ◽

10.3390/en11092250 ◽

2018 ◽

Vol 11 (9) ◽

pp. 2250 ◽

Cited By ~ 5

Author(s):

Rui Wang ◽

Qiuye Sun ◽

Qifu Cheng ◽

Dazhong Ma

Keyword(s):

Stability Analysis ◽

Solid State ◽

Single Phase ◽

Control Strategies ◽

Current Source ◽

Practical Stability ◽

Stability Assessment ◽

Solid State Transformer ◽

The Stability ◽

Signal Sinusoïdal

This paper proposes an overall practical stability assessment for a multi-port single-phase solid-state transformer (MS3T) in the electromagnetic timescale. When multiple stable subsystems are combined into one MS3T, the newly formed MS3T has a certain possibility to be unstable. Thus, this paper discusses the stability assessment of the MS3T in detail. First and foremost, the structure of the MS3T and its three stage control strategies are proposed. Furthermore, the stability analysis of each of the MS3T’s subsystems is achieved through the closed loop transfer function of each subsystem, respectively, including an AC-DC front-end side converter, dual active bridge (DAB) with a high-frequency (HF) or medium-frequency (MF) transformer, and back-end side incorporating DC-AC and dc-dc converters. Furthermore, the practical impedance stability criterion in the electromagnetic timescale, which only requires two current sensors and one external high-bandwidth small-signal sinusoidal perturbation current source, is proposed by the Gershgorin theorem and Kirchhoff laws. Finally, the overall stability assessment, based on a modified impedance criterion for the MS3T is investigated. The overall practical stability assessment of the MS3T can be validated through extensive simulation and hardware results.

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Torsional failure of water-filled carbon nanotubes

International Journal of Damage Mechanics ◽

10.1177/1056789515610397 ◽

2015 ◽

Vol 25 (1) ◽

pp. 87-97 ◽

Cited By ~ 3

Author(s):

Hongfei Ye ◽

Rui Li ◽

Yonggang Zheng ◽

Zhongqiang Zhang ◽

Zhi Zong ◽

...

Keyword(s):

Carbon Nanotubes ◽

Failure Behavior ◽

Stability Assessment ◽

Water Density ◽

Failure Angle ◽

Water Filling ◽

The Stability ◽

Dynamics Simulations ◽

Density Of Water ◽

Torsional Property

The failure behavior of water-filled carbon nanotubes under the torsional moment is investigated by molecular dynamics simulations. The computational results indicate that the shear modulus can be slightly increased but the critical buckling angle can be greatly enhanced by the water filling as compared to the empty carbon nanotubes. The enhancement in the critical buckling angle is almost comparable to that induced by the copper filling. However, the critical failure angle of carbon nanotubes decreases with the increase in the packing density of water, and it is reduced by about 50% when the water density reaches 1.2 g/cm3. Moreover, the researches on the defective water-filled carbon nanotubes reveal that the torsional property of the carbon nanotubes can be influenced by the density and distribution of the Stone–Wales defects. The present findings can provide a theoretical guidance for the stability assessment of nanochannels and the potential application for the drug delivery and release.

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The effect of storage on the colour of paprika powders with added oleoresin

Acta Universitatis Sapientiae Alimentaria ◽

10.1515/ausal-2016-0005 ◽

2016 ◽

Vol 9 (1) ◽

pp. 50-59

Author(s):

Zs. H. Horváth

Keyword(s):

Natural Food ◽

Colour Measurements ◽

Food Colour ◽

Powder Samples ◽

Paprika Oleoresin ◽

Colour System ◽

Plant Grown ◽

Cielab Colour ◽

Colour Coordinates ◽

Food Colours

Abstract The use of natural food colours is preferred to that of artificial dyestuffs for modern alimentary purposes. Paprika is a spice plant grown and consumed in considerable quantities worldwide and also used as a natural food colour, so the colouring power of powders is very important. The colour of paprika powder is highly relevant too because the consumer concludes its colouring power based on its colour. The colouring power of paprika powders is directly determined by the quality and quantity of the colouring agent of paprika. The paprika oleoresin, that is an oil soluble extract from the fruits of Capsicum Annum Linn or Capsicum Frutescens, is suitable to raise the colour agent content of paprika powders. We investigated how the colour and the characteristics of paprika powder samples with added oleoresin change in the course of storage. The colour agent content of 7 different quality powders was increased with 7-75% using oleoresin. The initial colour agent content of samples changed between 41 and 169 ASTA units. The powders were made from Chinese, Peruvian, and Hungarian paprika. Colour measurements were performed with a HunterLab MiniScan colour-measuring instrument. The CIELab colour system was used for colour characterization. The colour agent content and the colour coordinates of samples were measured throughout 9 months. The decrease of colour agent content varied between 22 and 51 percent, while the average reduction was 33 percent. The quantity of added oleoresin did not influence the colour agent content decrease significantly. The values of colour difference changed between 2 and 4.5 units. The initial paprika powder influenced the variation significantly, but the quantity of added oleoresin did not have a significant effect.

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Stability Assessment of Earth Retaining Structures under Static and Seismic Conditions

Infrastructures ◽

10.3390/infrastructures4020015 ◽

2019 ◽

Vol 4 (2) ◽

pp. 15

Author(s):

Nimbalkar ◽

Pain ◽

Ahmad ◽

Chen

Keyword(s):

Retaining Wall ◽

Earth Pressure ◽

Accurate Estimation ◽

Engineering Practice ◽

Active Earth Pressure ◽

Stability Assessment ◽

Linear Distribution ◽

Backfill Soil ◽

The Stability ◽

Seismic Earth Pressure

An accurate estimation of static and seismic earth pressures is extremely important in geotechnical design. The conventional Coulomb’s approach and Mononobe-Okabe’s approach have been widely used in engineering practice. However, the latter approach provides the linear distribution of seismic earth pressure behind a retaining wall in an approximate way. Therefore, the pseudo-dynamic method can be used to compute the distribution of seismic active earth pressure in a more realistic manner. The effect of wall and soil inertia must be considered for the design of a retaining wall under seismic conditions. The method proposed considers the propagation of shear and primary waves through the backfill soil and the retaining wall due to seismic excitation. The crude estimate of finding the approximate seismic acceleration makes the pseudo-static approach often unreliable to adopt in the stability assessment of retaining walls. The predictions of the active earth pressure using Coulomb theory are not consistent with the laboratory results to the development of arching in the backfill soil. A new method is proposed to compute the active earth pressure acting on the backface of a rigid retaining wall undergoing horizontal translation. The predictions of the proposed method are verified against results of laboratory tests as well as the results from other methods proposed in the past.

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