Research on Contact Strength between Roller Screw Pair on Hoisting Mechanism Applied in Deep Sea Crane

2013 ◽  
Vol 423-426 ◽  
pp. 2001-2005 ◽  
Author(s):  
Hui Wang ◽  
Min Hui Tong ◽  
Pei Zheng
Keyword(s):  
Deep Sea ◽  
Major Part ◽  
Large Diameter ◽  
Surface Hardness ◽  
Contact Problems ◽  
Theoretical Support ◽  
Roller Screw ◽  
New Type ◽  
Marine Engineering ◽  
The Impact

Roller screw pair is the major part of the rope guiding device that used in deep-sea hoisting mechanism. This paper focuses on the contact problems of the roller screw pair. The hoisting mechanism used in the deep sea engineering has the rope with large diameter, sustaining the great rope tension force. So its important to research the contact stress of the roller screw, This paper study the impact of surface hardness of the roller on the performance of the roller screw, sums up the effect of hardness on the bearing capacity of the roller, and provides the theoretical support and references for the designing and application of this new type of roller screw in marine engineering.

Environmental impact of nutrients from nordic fish farming

1995 ◽  
Vol 31 (10) ◽  
pp. 61-71 ◽  
Author(s):  
M. Enell
Keyword(s):  
Major Part ◽  
Fish Farming ◽  
Fish Farms ◽  
Feed Composition ◽  
The North ◽  
Comprehensive Development ◽  
The Baltic ◽  
Inland Water Bodies ◽  
The Impact ◽  
Feed Coefficient

During the last 20 years there has been an interesting development of the Nordic fish farming, with regard to the feeding and farming technology and to the increase in production quantities. During the period 1974-1994 the production increased from 15,800 to about 250,000 tonnes/year. In 1974 the major part of the production was in Denmark, and in 1994 the major part was in Norway. The nutrient impact of fish farming on surrounding sea areas is mainly a function of the feed coefficient, the feed composition and metabolic processes in the fish. The comprehensive development of the feed composition and the feeding technology has resulted in reduced load of unmetabolized nutrients from fish farms, calculated per tonne fish produced. In 1974 the mean Nordic feed coefficient was 2.08 and in 1994 the coefficient was 1.25. Feed coefficients of 1.0-1.1 are now reported for Danish and Norwegian freshwater and marine fish farms. The nitrogen (N) and phosphorus (P) content of the feed has decreased, in addition the quality of the nutrient substances in the feed has changed, especially for N. The N content has decreased from 7.8 to 6.8% during the period 1974-1994 and the content of P has decreased from 1.7 to 0.7% during the same period. This development of the feed coefficient and the feed composition has resulted in a present load from a typical Nordic fish farm of 55 kg N and 4.8 kg P/t fish produced. The figures for 1974 were 132 kg N and 31 kg P/t fish produced. The Nordic fish farming production in 1994 resulted in a load of about 13,750 t N and about 1,200 t P on the actual recipients. The load from the Swedish, Finnish and Danish fish farming operations, with the Baltic Sea and the Skagerrak as the recipients, is negligible in comparison with other pollution sources. The quantities of N and P from the fish farming are equal to 0.5% of the atmospheric deposition on the sea surface and 3% of the atmospheric P load. Norwegian, Icelandic and the Faroe Islands fish farming operations are using the North Sea and the Norwegian Sea as the recipients. However, the nutrient load from single fish farms in certain coastal and inland water bodies can be significant and must be considered in the impact assessment together with other sources.

Predicting the number of fiber roots in lola drafting based on multi-field coupling

2020 ◽  
Vol 90 (23-24) ◽  
pp. 2769-2781
Author(s):  
Xin rong Li ◽  
LiuBo Wu ◽  
Zhaoning Bu ◽  
Lidong Liu
Keyword(s):  
Change Point ◽  
Production Efficiency ◽  
Slip Rate ◽  
Sharp Decrease ◽  
Coupling Model ◽  
Production Costs ◽  
Weak Effect ◽  
Field Coupling ◽  
Theoretical Support ◽  
New Type

Pullout theory is very important in improving efficiency, quality, and production costs. Because production efficiency is too low for mechanical drafting equipment, a simple multi-field coupling model of fiber mechanics based on conserving momentum is proposed that considers the distribution of the fiber speed point, slip rate, and friction mechanics. When the roller draft multiple is increased, the position near the rear roller clamp mouth in the draft area will show a sharp decrease of fiber, which is caused by the rapid movement of the front fiber to drive the floating fiber movement, and it is also the existence of the fiber change point. When the roller spacing increases, the draft efficiency decreases, although the pressure applied by the roller to the fibrous strip has a weak effect on the draft efficiency. This research increases our understanding of drawing and provides theoretical support for the design of a new type of drawing.

scholarly journals Influence of Whey Protein Micro-Gel Particles and Whey Protein Micro-Gel Particles-Xanthan Gum Complexes on the Stability of O/W Emulsions

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2301
Author(s):  
Man Zhang ◽  
Bin Liang ◽  
Hongjun He ◽  
Changjian Ji ◽  
Tingting Cui ◽  
...  
Keyword(s):  
Oxidative Stability ◽  
Whey Protein ◽  
High Speed ◽  
Xanthan Gum ◽  
Physical Stability ◽  
Theoretical Support ◽  
Gel Particles ◽  
Oil In Water ◽  
The Stability ◽  
The Impact

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

scholarly journals Elastic Modulus and Elasticity Ratio of Malignant Breast Lesions with Shear Wave Ultrasound Elastography: Variations with Different Region of Interest and Lesion Size

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1015
Author(s):  
Antonio Bulum ◽  
Gordana Ivanac ◽  
Eugen Divjak ◽  
Iva Biondić Špoljar ◽  
Martina Džoić Dominković ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Shear Wave ◽  
Large Diameter ◽  
Small Diameter ◽  
Shear Wave Elastography ◽  
Lesion Size ◽  
Ultrasound Elastography ◽  
Breast Lesions ◽  
Malignant Breast ◽  
The Impact

Shear wave elastography (SWE) is a type of ultrasound elastography with which the elastic properties of breast tissues can be quantitatively assessed. The purpose of this study was to determine the impact of different regions of interest (ROI) and lesion size on the performance of SWE in differentiating malignant breast lesions. The study included 150 female patients with histopathologically confirmed malignant breast lesions. Minimal (Emin), mean (Emean), maximal (Emax) elastic modulus and elasticity ratio (e-ratio) values were measured using a circular ROI size of 2, 4 and 6 mm diameters and the lesions were divided into large (diameter ≥ 15 mm) and small (diameter < 15 mm). Highest Emin, Emean and e-ratio values and lowest variability were observed when using the 2 mm ROI. Emax values did not differ between different ROI sizes. Larger lesions had significantly higher Emean and Emax values, but there was no difference in e-ratio values between lesions of different sizes. In conclusion, when measuring the Emin, Emean and e-ratio of malignant breast lesions using SWE the smallest possible ROI size should be used regardless of lesion size. ROI size has no impact on Emax values while lesion size has no impact on e-ratio values.

The Impact of Ongoing COVID-19 Stress on the General Population the Case for a New Type of Psychiatric Stress Disorder

2020 ◽  
Author(s):  
Sari Goldstein Ferber ◽  
Gal Shoval ◽  
Viviana Trezza ◽  
Giorgio Di Lorenzo ◽  
Rodolfo Rossi ◽  
...  
Keyword(s):  
General Population ◽  
Stress Disorder ◽  
New Type ◽  
The Impact

A study on the impact of digital tobacco logistics on tobacco supply chain performance: taking the tobacco industry in Guangxi as an example

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaoping Shen ◽  
Yeheng Zhang ◽  
Yumei Tang ◽  
Yuanfu Qin ◽  
Nan Liu ◽  
...  
Keyword(s):  
Supply Chain ◽  
Tobacco Industry ◽  
Indicator System ◽  
Supply Chain Performance ◽  
Dynamics Model ◽  
Content Type ◽  
Chain Operation ◽  
Theoretical Support ◽  
Supply Chain Operation ◽  
The Impact

PurposeThis paper, with the tobacco industry as the background, establishes an indicator system for tobacco supply chain performance evaluation using the FAHP method.Design/methodology/approachBased on the relevant data of tobacco enterprises in Guangxi, the paper calculates the performance values of tobacco companies in various cities of Guangxi, and through the analysis of each indicator and the performance values of each city, the authors find that the improvement ability has a major impact on tobacco supply chain performance. Then, the paper establishes a system dynamics model to further demonstrate the impact of information digitalization on the performance of the tobacco supply chain in Guangxi, thus providing theoretical support for building digital tobacco logistics in Guangxi.FindingsThe findings of the study show that the performance of the tobacco supply chains in various cities of Guangxi is generally at the level of “Pass–Good,” which can barely meet the requirements of tobacco supply chain operation, but there is still plenty of room for improvement.Originality/valueThe authors show that digital and IT-based empowerment can maximize the performance of Guangxi's tobacco logistics performance.

THM analysIs of natural and engineered barriers for large excavations in deep nuclear waste repository

2021 ◽  
Author(s):  
Matias Alonso ◽  
Jean Vaunat ◽  
Minh-Ngoc Vu ◽  
Antonio Gens
Keyword(s):  
Nuclear Waste ◽  
Host Rock ◽  
Thermal Load ◽  
Water Pressure ◽  
Large Diameter ◽  
Coupled Processes ◽  
Nuclear Waste Repository ◽  
Damaged Zone ◽  
Waste Repository ◽  
The Impact

&lt;p&gt;Argillaceous rocks have great potential as possible geological host medium to store radioactive waste. &amp;#160;Andra is leading the design of a deep geological nuclear waste repository to be located in the Callovo-Oxfordian formation. In the framework of this project, excavations of large diameter galleries are contemplated to access and to store intermediate-level long-lived nuclear waste at repository main level. The closure of the repository will be realized by building sealing structures of expansive material.&lt;/p&gt;&lt;p&gt;The response of such structures is affected by several thermo-hydro-mechanical coupled processes taking place in the near and far field of the argillaceous formations. They include the formation of an excavation induced damaged zone around the galleries, the impact of the thermal load on host rock pressures and deformations, the long-term interaction with support concrete structural elements and the hydration and swelling of sealing materials. As a result, the study of their performance requires to perform simulation works of increasing complexity in terms of coupling equations, problem geometry and material behaviour. As well, challenging computational aspects, as the ones related to fractures creation and propagation, have to be considered for a representative analysis of the problem.&lt;/p&gt;&lt;p&gt;This work presents advanced large scale THM numerical models to provide keys about the response of the host rock around large diameter galleries during excavation and further thermal load as well as to analyse the performance of large diameter sealing structures. Particular features of the models include on one hand advanced constitutive laws to capture the development of the fractured zone around excavations, the behaviour of host rock/gallery support interfaces and the multi-scale response of bentonitic backfill. On the other hand, simulations consider geometries including constructive details of interest at decimetre scale within large discretization domain covering the whole formation stratigraphic column.&lt;/p&gt;&lt;p&gt;These challenging simulations provided qualitative and quantitative results on key aspects for natural and engineered barrier integrity, like extension of the damaged zone, impact of the thermal load and water pressure variations in the surrounding geological layers, duration of natural hydration phase, swelling pressure development and seals global stability.&lt;/p&gt;

Using the Concept of “Social Distancing” in Advertising Designs: A Comparative Analysis

2021 ◽  
Author(s):  
Begüm Aylin Önder
Keyword(s):  
Corporate Social Responsibility ◽  
Comparative Analysis ◽  
Social Responsibility ◽  
Social Benefit ◽  
Global Scale ◽  
Social Distancing ◽  
Corona Virus ◽  
New Type ◽  
Corporate Social ◽  
The Impact

Corporate social responsibility is one of the activities that goes beyond philanthropy, based on volunteerism in line with the responsibilities of enterprises towards society. This concept, which offers businesses the opportunity to look after and develop their brand image in the eyes of society, has become a necessity, not a choice, especially in today's world. In order to meet social expectations, the effectiveness of static and dynamic advertising messages implemented in all social benefit-based studies for human development such as environment, health and education is very important in terms of ensuring audience communication. In the second half of 2019, people were confined to homes and life came to a standstill all over the world in order to reduce and prevent the impact of the pandemic within the scope of the “New Type Corona Virus” (COVID-19) measures, which are from the sars-cov-2 coronavirus family, which is spreading rapidly globally starting from Wohan, Hubei Province, China. As a basic protection module for humanity against corona virus, it has incorporated the concept of social distancing into their lives in order to reduce the contact of staying at home and increasing hygiene, except in mandatory situations. During this extraordinary period, many brands on a global scale have included the concept of “social distance” in their advertising messages with the awareness of corporate social responsibility and have started to inform and educate the community about this issue by emphasizing the importance of the process. Within the scope of this research, advertising designs prepared by brands acting with corporate social responsibility awareness through the concept of social distancing during the Pandemic period were discussed and how the meaning structures behind the messages were created and transmitted. The research is limited to 3 (three) advertising designs determined by the 'judicial sampling' method (selective method). In the sample of the study, advertising narratives of brands in different sectors were explained in general framework and similar and different aspects of messages were uncovered by performing comparative analysis between messages in line with the findings obtained from the narratives. In this context, it was determined that the contrasts of “pessimism and optimism, hope and despair, happiness and unhappiness, death and life, strong and powerless, youth and old age, unity/togetherness and separation, struggle and defeat, nature and culture” were constructed as the main discourse.

New Type of Hydraulic Rotary Actuator; Development and Application in a Large Telerobotic Manipulator System

2001 ◽  
Author(s):  
John R. Haas
Keyword(s):  
Modular Design ◽  
Large Diameter ◽  
Stick Slip ◽  
Precision Motion Control ◽  
Constant Torque ◽  
Rotary Actuator ◽  
Continuous Rotation ◽  
Potential Applications ◽  
New Type ◽  
Precision Motion

Abstract This paper describes a new type of hydraulic rotary actuator specifically developed to provide precision motion control in a very large, man rated, underwater telerobotic manipulator system. The high pressure, high torque rotary actuators are hydrostatically balanced, provide continuous rotation, constant torque output, exhibit minimal “stick-slip” and zero backlash. It is believed that the combination of features and the performance exhibited by these actuators represent an improvement in actuator technology to such an extent as to make projects previously determined unfeasible, now practical. Features of particular design value are a very large diameter through bore, and a truly modular design permitting use as an integral structural member. This paper will address design rationale, operating principles, key design features, product development highlights, an astronaut trainer case study, future development and potential applications.

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