Optimal Design of Stewart Platform Safety Mechanism

A safety mechanism capable of moving at will within the range of its whole link lengths is designed based on the link space. Sixteen extreme poses are obtained in a Stewart platform. The singular points of the extreme poses are solved by using homotopy method as well as the judgment condition of singular points, and thereby the maximum link lengths are achieved. The rotation angles of joints and the distances between two neighboring links are analyzed in a calculation example in which that the mechanism moves among the extreme poses is assumed. Then an algorithm to test the safety mechanism is presented taking the constraint conditions into account. A safety mechanism having optimal properties of global movement is worked out by optimizing all structural parameters through minimizing the average condition number of extreme poses.

Impact of Improving Design Factor over 0.72 on the Safety and Reliability of Gas Pipelines and Feasibility Justification

Many years experience of the operation of high stress (>72% specified minimum yield strength, SMYS) gas pipelines and statistical analysis results of pipeline incidents showed that the operating pipelines at stress levels over 72% SMYS have not presented problems in USA and Canada, and design factor does not control incidents or the safety of pipelines. Enhancing pipeline safety management level is most important for decreasing incident rate. The application history of higher design factors in the U.S and Canada was reviewed. And the effect of higher factors to the critical flaw size, puncture resistance, change of reliability with time, risk level and the arrest toughness requirements of pipeline were analyzed here. The comparison of pipeline failure rates and risk levels between two design factors (0.72 and 0.8) has shown that a change in design factor from 0.72 to 0.8 would bring little effect on failure rates and risk levels. On the basis of the analysis result, the application feasibility of design factor of 0.8 in China was discussed and the related suggestions were proposed. When an operator wishes to apply design factor 0.8 to gas pipeline, the following process is recommended: stress level of line pipe hydro test should be up to 100% SMYS, reliability and risk assessment at the design feasibility or conceptual stage should be conducted, Charpy impact energy should meet the need of pipeline crack arrest; and establish and execute risk based integrity management plan. The technology of pipeline steel metallurgy, line pipe fabrication and pipeline construction, and line pipe quality control level in China achieved tremendous progresses, and line pipe product standards and property indexes have come up to international advanced level. Furthermore, pipeline safety management has improved greatly in China. Consequently, the research for the feasibility of application of design factor of 0.8 in China has fundamental basis.

Design methodology for the safety of underground rock engineering

In order to optimise the safety of underground rock engineering construction and the long-term security of the resultant facilities, it is necessary to have a knowledge of the likely hazards. These risks or hazards fall into the four categories of 'known beforehand and relatively easily addressed', 'known beforehand and not easily addressed', 'not known beforehand and relatively easily addressed', and 'not known beforehand and not easily addressed'. This paper describes how these four types of hazard can be incorporated into a design methodology approach, including the process by which the relevant mechanical rock mass parameters can be recognised for modelling and hence predictive purposes. In particular, there is emphasis on the fact that information and judgement are the keys to safety——whether the hazards are known or unknown before construction proceeds.

Influential Factors in Safety Design of Aircraft Pneumatic Duct System

The reliability and safety of the pneumatic ducts are essential for flight safety.A beam element model of the duct system is developed and the factors that impact the stress performance of the duct system are investigated,such as stress check standards,flight acceleration,internal temperature and internal pressure.The results show that the stress synthetic method as the stress check standard can obtain the more safety design results.The maximum stress of straight pipe is affected significantly by the acceleration in a plane perpendicular to straight pipe,while the maximum stress of bend pipe is greatly affected by the acceleration in the direction perpendicular to plane of the bend pipe.Meanwhile,internal pressure has little effect on the maximum stress of bend pipe and straight pipe.Temperature has little effect on the maximum stress of bend pipe while has a big impact on the maximum stress of straight pipe.

Open-Type Ferry Safety System Design for Using LNG Fuel

In this feasibility study, we investigate the viability of using Liquefied Natural Gas （LNG） fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship.

Highway Planning and Design in the Qinghai–Tibet Plateau of China: A Cost–Safety Balance Perspective

Engineering designs for mountainous highways emphasize compliance checking to ensure safety. However, relying solely on compliance checking may lead designers to minimize costs at the expense of high risk indicators, since the overall risk level of the highway design is unknown to the designers. This paper describes a method for the simultaneous consideration of traffic safety risks and the associated cost burden related to the appropriate planning and design of a mountainous highway. The method can be carried out in four steps: First, the highway design is represented by a new parametric framework to extract the key design variables that affect not only the life-cycle cost but also the operational safety. Second, the relationship between the life-cycle cost and the operational safety risk factors is established in the cost-estimation functions. Third, a fault tree analysis (FTA) is introduced to identify the traffic risk factors from the design variables. The safety performance of the design solutions is also assessed by the generalized linear-regression model. Fourth, a theory of acceptable risk analysis is introduced to the traffic safety assessment, and a computing algorithm is proposed to solve for a cost-efficient optimal solution within the range of acceptable risk, in order to help decision-makers. This approach was applied and examined in the Sichuan–Tibet Highway engineering project, which is located in a complex area with a large elevation gradient and a wide range of mountains. The experimental results show that the proposed approach significantly improved both the safety and cost performance of the project in the study area.

Modular Design Using Sustainable Luminescent Materials in Energy-Saving Reflective Cat’s Eyes for Public Road Safety Planning

Recently,there has been a global movement toward environmental protection and energy conservation through the design and development of new products in accordance with sustainable utilisation.In this study,rare earth luminescent materials were used owing to their active light emission and reusability.Additionally,solar lightemitting diode lights and car-light reflection were utilised to increase the recognition and reliability of reflective cat eyes.Along with carbon reduction,this can save energy and enhance road safety.This study considered the Theory of Inventive Problem Solving and a literature review to analyse the issues in existing products.Then,expert interviews were conducted to screen projects and develop product design policies.Finally,the ratio of light-storage materials was experimentally determined and the prototypes implemented.This cat’s eye addresses the shortcomings identified in previous analyses of existing products.We applied energy storage environmental protection materials,together with material proportioning(which balanced warning efficiency against cost-effectiveness)to develop diversified modular kits;these were flexible in terms of quantity and easily assembled.This study achieved four key objectives:(1)reducing the research and development costs of the manufacturer;(2)offering buyers a diverse suite of products;(3)responding to a need to improve diverse road user safety;and(4)reducing government procurement costs for safety warning products.The results provide a reference for the creative modular design of energy-saving products for public road safety planning in various industries.

Optimization design of deep lean-ore mining and safety evaluation

In order to settle the mining optimization design and safety problem of the above 1 150 m pillar of No.1 ore-body in No.H Mining Jinchuan, the lean-ore above 1 250 m, the 1 150 m horizontal pillar and the ore-body below 1 100 m regarded as research objects based on the original design project, and nine calculation schemes on different mining sequence and different fill body strength were put forward based on cement-sand ratio of 1 ： 4, 1： 12 and 1 ： 24. Calculation parameters were got by the back analysis method of field monitoring data, and the FLAC2D program was applied to compute for these schemes, stress and displacement of ground settlement, shaft and stope roof were analyzed, and some conclusions were got. Results show that the intensity of filling body and the mining technique have very important effect on controlling settlement and stability of surrounding rock; Developing of lean ore have some influences to the 16th return air filling shaft, especially for 1 500--1 400 m of the shaft; The best project is the first project. This research supply some technique references and safety appraisals for the mining of lean-ore of No.II Mining Jinchuan.

The Design of Urban Road Manhole Covers Based on the Function of Safety and Identification

This study combed the development process of urban road manhole cover at home and abroad,and pointed out the existing problems in the domestic manhole cover.From the perspective of safety and identification function,it put forward innovative design ideas of urban road manhole covers to improve the safety and identification function of road manhole covers,and enhance the ornamental of manhole covers.

Safety Design Strategy for Highway Interchange Exit Ramp

Highway is an important type of road in China’s road network,and it also carries a larger portion of transportation task.Safety is the first indicator in the stage of its use,so it is necessary to carry out safety design focusing on the highway interchange exit ramp to effectively prevent traffic accidents.Therefore,in this paper,the important significance of the safety design of the highway interchange exit ramp and the key factors affecting its safety were discussed and studied in detail,and finally corresponding strategies were proposed for discussion and communication.

Analysis on Safety Influencing Factors on Highway Interchange Design

This paper briefly introduces the safety performance of the highway interchange design.The factors that influence the safety of the highway interchange design,was discussed in the paper based on the parts,which are the safety of the interchange location,the safety of interchange form,and the safety design of the main line in interchange.

Safety Design and Verification Analysis in the Satellite Development Stage

A safety design applies to every stage in a satellite system development life cycle to identify and analyze hazards in the satellite at a system level, eliminating or controlling various safety risks, while verifying the functions of the satellite system have safety characteristics, so as to optimize the satellite system for the best performance in terms of time and cost. This article comprehensively leverages such factors as satellite reliability, complexity and life cycle by considering the overall satellite safety work plan, hazard analysis, hazard sources, pyrotechnic devices and other module safety critical designs. Safety design measures were formulated to review and verify the effectiveness of system functions including a safe power supply to a satellite and pyrotechnic explosives to achieve the safety requirements of the satellite from a development stage. Safety design activities for each subsystem will ensure meeting the development requirements of the satellite system as a whole, and ensure the satellite system cannot be the cause of casualties, equipment damage, property loss, or have a health-threatening impact or detrimental impact on the environment.

Analysis of the Relations between Highway Geometric Design and Traffic Safety in Bangladesh,China,and America

Transportation plays a critical role in the economic sector in Bangladesh.Since its independence,infrastructure has been developing rapidly,includ-ing land,water,and air transportation.National economy is increasing at a relatively high rate,leading to the better-off of people’s lives.As the living standards keep improving,people are more concerned about safety issues in transportation.This article makes an analysis of the status quo of traffic safety in Bangladesh and compares the Bangladeshi code with American code AASHTO from the geometric aspects of horizontal and vertical align-ment,in an effort to provide reference to the highway design in Bangla-desh.Through a reasonable design,the traffic safety will be under control and accident rate as well as economic loss will be minimized.

The Human-Machine Safety Design of Mechanical Toys for Children

In order to ensure the safety of children while using machineries and avoid harm caused by mechanical toys,this paper analyzes the types and detection standards of children’s toys,discusses the reasons for the harm caused by these toys,and proposes human-machine safety design strategies for children’s toys as reference.

Design Pattern Representation for Safety-Critical Embedded Systems

Design Patterns, which give abstract solutions to commonly recurring design problems, have been widely used in the software and hardware domain. As non-functional requirements are an important aspect in the design of safety-critical embedded systems, this work focuses on the integration of non-functional implications in an existing design pattern concept. We propose a pattern representation for safety-critical embedded application design methods by including fields for the implications and side effects of the represented design pattern on the non-functional requirements of the overall systems. The considered requirements include safety, reliability, modifiability, cost, and execution time.

The safety aspect of sodium ion batteries for practical applications

Sodium-ion batteries(SIBs)with advantages of abundant resource and low cost have emerged as promising candidates for the next-generation energy storage systems.However,safety issues existing in electrolytes,anodes,and cathodes bring about frequent accidents regarding battery fires and explosions and impede the development of high-performance SIBs.Therefore,safety analysis and high-safety battery design have become prerequisites for the development of advanced energy storage systems.The reported reviews that only focus on a specific issue are difficult to provide overall guidance for building high-safety SIBs.To overcome the limitation,this review summarizes the recent research progress from the perspective of key components of SIBs for the first time and evaluates the characteristics of various improvement strategies.By orderly analyzing the root causes of safety problems associated with different components in SIBs(including electrolytes,anodes,and cathodes),corresponding improvement strategies for each component were discussed systematically.In addition,some noteworthy points and perspectives including the chain reaction between security issues and the selection of improvement strategies tailored to different needs have also been proposed.In brief,this review is designed to deepen our understanding of the SIBs safety issues and provide guidance and assistance for designing high-safety SIBs.

Design,preparation,application of advanced array structured materials and their action mechanism analyses for high performance lithium-sulfur batteries

Lithium-sulfur battery(LSB)has brought much attention and concern because of high theoretical specific capacity and energy density as one of main competitors for next-generation energy storage systems.The widely commercial application and development of LSB is mainly hindered by serious“shuttle effect”of lithium polysulfides(Li PSs),slow reaction kinetics,notorious lithium dendrites,etc.In various structures of LSB materials,array structured materials,possessing the composition of ordered micro units with the same or similar characteristics of each unit,present excellent application potential for various secondary cells due to some merits such as immobilization of active substances,high specific surface area,appropriate pore sizes,easy modification of functional material surface,accommodated huge volume change,enough facilitated transportation for electrons/lithium ions,and special functional groups strongly adsorbing Li PSs.Thus many novel array structured materials are applied to battery for tackling thorny problems mentioned above.In this review,recent progresses and developments on array structured materials applied in LSBs including preparation ways,collaborative structural designs based on array structures,and action mechanism analyses in improving electrochemical performance and safety are summarized.Meanwhile,we also have detailed discussion for array structured materials in LSBs and constructed the structure-function relationships between array structured materials and battery performances.Lastly,some directions and prospects about preparation ways,functional modifications,and practical applications of array structured materials in LSBs are generalized.We hope the review can attract more researchers'attention and bring more studying on array structured materials for other secondary batteries including LSB.

Synthesis,characterization,safety design,and application of NPs@BC for contaminated soil remediation and sustainable agriculture

Biochar(BC)and nanoparticle-decorated biochar(NPs@BC)have emerged as potential high-performance function materials to facilitate simultaneous soil remediation and agricultural production.Therefore,there is an urgent need to incorporate environmental sustainability and human health targets into BC and NPs@BC selection and design processes.In contrast to extensive research on the preparation,modification,and environmental application of BC to soil ecosystems,reports about the adapted framework and material selection strategy of NPs@BC under environmental and human health considerations are still limited.Nevertheless,few studies systematically explored the impact of NPs@BC on soil ecosystems,including soil biota,geochemical properties,and nutrient cycles,which are critical for largescale utilization as a multifunctional product.The main objective of this systematic literature review is to show the high degrees of contaminant removal for different heavy metals and organic pollutants,and to quantify the economic,environmental,and toxicological outcomes of NPs@BC in the context of sustainable agriculture.To address this need,in this review,we summarized synthesis techniques and characterization,and highlighted a linkage between the evolution of NPs@BC properties with the framework for sustainable NPs@BC selection and design based on environmental effects,hazards,and economic considerations.Then,research advances in contaminant remediation for heavy metals and organic pollutants of NPs@BC are minutely discussed.Eventually,NPs@BC positively acts on sustainable agriculture,which is declared.In the meantime,evaluating from the perspective of plant growth,soil characterizations as well as carbon and nitrogen cycle was conducted,which is critical for comprehending the NPs@BC environmental sustainability.Our work may develop a potential framework that can inform decision-making for the use of NPs@BC to facilitate promising environmental applications and prevent unintended consequences,and is expected to guide and boost the development of highly efficient NPs@BC for sustainable agriculture and environmental applications.

Urban design based on public safety-Discussion on safety-based urban design

Because of public safety problems in construction of urban surroundings,this paper expounds the necessity of the study on public safety-based urban design in perspective of modern city.It brings forward the concept of safety-based urban design and attempts to explore the basic connotation and contents with framework for studies.

Integrated risk management: a Petrobras application in offshore well construction safety to minimize critical emergency disconnections

In order to avoid mistakes and to save a great deal of time in analysis, an innovative methodology was developed that can analyze the well operations and rig characteristics involved to define the best emergency disconnect sequence （EDS） available. A solution was developed based on the characteristics of the rigs and blowout preventers （BOPs）, and six variables were considered that directly affect the choice of EDS. All possible combinations of 64 scenarios were analyzed, and the priority of choice of the EDS was defined empirically. This paper presents an approach to EDS risk management and examples of exposure time （time without riser safety margin and shear capability） for the same well, which can be lowered from 13% to 0.1%. The impact of this reduction is related to the ability of the BOP to cut some of the heavy casings, in addition to improved availability of EDS modes. This implementation opened up many possibilities for the performance of risk exposure analysis, enabling comparison of several BOP configurations of contracted rigs and selection of the best options. This innovative approach allowed a better management of the rig schedules, prioritizing safety aspects and making it possible to allocate the fleet in a systematic way.