Daizhong Su

Comparative life cycle assessment of LED lighting products

The use of LED lighting products is growing rapidly. However, there are no in-depth, updated studies that show how to assess and compare these products for eco-design purposes. This research aims to inform eco-design by assessing and comparing the environmental impact of a new LED eco-lighting product with an existing LED lighting product. A cradle to grave life cycle assessment is conducted. The system boundaries include all product life cycle stages, except the maintenance of the luminaires and the manufacturing of the packaging. A novel functional unit is defined for the assessment, which is more suitable for LED lighting products. Six scenarios are considered, including three probable useful lives of the luminaires (1000, 15,000 and 40,000 hours) and two end of life options (domestic bin and recycling centre). The life cycle assessment results reveal that the new eco-lighting product has about 60% less environmental impact than the existing lighting product in all scenarios. The life cycle stages with the biggest impacts are, in decreasing order: (1) use, (2) manufacturing, (3) end of life and (4) transport. Recommendations for the eco-design of LED lighting products are proposed, and the challenges in applying life cycle assessment for eco-design are discussed.

Extending the lifespan of LED-lighting products

Light Emitting Diodes (LED) lighting products require more reliable data to inform Life Cycle Assessment. Understanding why and when they fail under real operating conditions provides better data for this assessment contributing to: (1) understanding of how to extend its lifespan, (2) informing design recommendations to extend their lifespan and (3) reducing the total amount of waste produced by LED lighting products. This paper investigates the life span of LED lighting products under real operating conditions and explores the causes of failure or replacement of the products. The study consisted of close-ended questionnaires distributed to LED lighting product manufacturers and consumers in four EU countries. Out of 140 respondents of the questionnaire survey, 57 were manufacturing organizations and 83 were consumers. The results indicate that: (1) the causes of failure were primarily due to wear and tear of components, and changes in consumer requirements; (2) the consumers survey showed that, the lifespan is 27,375u2005h in the best case scenario and 1460u2005h in the worst case scenario, indicating that the worst case scenarios can be substantially improved through proper use and maintenance, as well as selection of products with features to enhance the lifespan; (3) the manufacturers survey showed that, the lifespan is 32,850u2005h in the best case scenario and 3650u2005h in the worst case scenario, indicating the need for better design and manufacturing guidelines to extend their lifespan. The paper concludes with recommendations for both manufacturers and consumers, based on a combined analysis of the survey data and a comprehensive literature review of recommendations to extend the lifespan of LED lighting products.

A meshing principle for generating a cylindrical gear using an Archimedes hob with two degrees of freedom

Abstract Thorough and systematic investigations are performed into the meshing principium of generating a cylindrical gear by an Archimedes hob based on the two-degree-of-freedom theory of gearing geometry. The numerical examples show the verification and validation of the formulated principium and the developed model. Conclusions suitable for industrial application are reached by means of numerical simulations.

Analysis and evaluation of the environmental impacts of 'upstream' petroleum operations

Abstract: Sustainability is increasingly considered an essential business function, but in Libya, petroleum companies are slow to address operational issues that could reduce environmental concerns. This study aims to evaluate the environmental impacts of upstream petroleum operations. The methods adopted in the study are a literature review, an environmental impact assessment (EIA) study and qualitative analyses from, fieldwork trials and 56 semi-structured interviews. The results of the study show that the main environmental impacts are aquatic, terrestrial or atmospheric, with the most significant pollutants linked to the latter category, mainly from engine exhausts, turbine emissions, gas flaring and venting. Major environmental degradations are identified in Libyan upstream operations and a number of recommendations formulated minimising their effect. Particular importance is placed on establishing strict sustainability policies and regulations, and the implementation of an environmental management system.

Application of PDA and Wireless Technology in a Server-Client Structure for Remote Machine Condition Monitoring

A remote online machine monitoring system is developed across a desktop PC and mobile devices to monitor and control machine’s working conditions. A server-client network structure is constructed for real time communication between server and client modules. Within the server module, data I/O (input/output) communication is utilised to acquire machine condition data and to pass control commands to the machine-controller interface; feature extraction and decision making are applied to detect machine’s operating status. The server and client modules allow mobile users to remotely access the server via PDA and Wireless Wi-Fi connectivity to regulate the machine conditions by tuning the controller parameters. Remote communication between the modules with different platforms/operating systems is implemented by combining the Web Service application program interface with MXML-based cross-platform programming standard. The system developed is validated by a case study of monitoring the working conditions of an air-conditioning system.

Motion state recognition of debris ejected in vehicular collision after contact with the ground

The motion state of debris ejected from the vehicle involved in vehicular collision is important for finding out the vehicle collision speed. This research developed an analytical model to recognise the debris motion state. With the model, analyses were conducted, which reveal that if α, which is the contact angle between the debris and the ground at the moment when the debris collides the ground, is within the range from 0° to its boundary value, then the debris slides; if α is within the range from its boundary value to 90°, then the debris bounces. With debris initial angular velocity ω = 0, the boundary value is 11.8° for sphere debris and 7.8° for rectangular debris; with ω ≠ 0, the boundary value for rectangular debris is arcsin(g / Rω2) where g represents the acceleration due to gravity and R is the distance from the debris centre to the point of its contact with the ground. Experiment tests were conducted for debris motion states with ω = 0, which confirmed the analytical results.

Effects of microbus front structure on pedestrian head injury

In order to study the effects of the microbus front structure on pedestrian head injury happened in pedestrian-microbus collisions, the mathematic models of the impact angle and microbus front configuration are developed, which illustrate the relationship between the impact angle, pedestrian size and oblique angles of the engine hood and windscreen. The mathematic models are then verified by simulating experiments using LY-Dyna. The impact angle α, which is measured between the contact surface and the pedestrian heads impact direction at the contact point, is an important parameter indicating the relationship of pedestrian head injury with the microbus front structure. The analysis and simulation results reveal that: 1) in the case of collision with the windscreen, the pedestrian head injury increases while α increases; 2) in the case of collision with the engine hood, the pedestrian head incurs the most serious injury when α = 90°, the pedestrian head injury increases while α increases when α 90°. Six microbus models are taken as examples to verify the results obtained.

Internet-based remote monitoring system of thermo-electric-generations with mobile communication technology

A remote online condition monitoring system for thermo-electric-generations (TEGs) is reported in this paper, which is applied in sustainable buildings. The system monitors the electrical power and heat energy generated by TEGs and to regulate the temperature of cold side of thermoelectric (TE) units used in the TEGs. The system provides the following major functions: data acquisition, data processing, system control and remote communication. The data acquisition module is built up within this system based on sensor technology and data I/O communication to acquire the data of working conditions of TEGs. System control is implemented by sending the commands to the control unit of the water valve for adjusting the temperature of cold side of TE units. The system has been validated by carrying out a case study of remote monitoring the working conditions of TEGs.

Analysis of the barriers to environmental management systems implementation in the Libyan oil industry

Adhering to an Environmental Management System (EMS) is the start point in moving an organisation towards a sustainable future. The aim of this study is to identify the barriers for effective implementation of an EMS (ISO4001) in the Libyan oil sector, which would benefit in smoother implementation in future and as a result will lead to environmental sustainability to the oil sector and the country as a whole. To meet the aim, literature reviews and interviews were carried out, and a case study of Azzawya Oil Company in Libya was conducted. The results of the study show that the most significant barriers are those related to poor leadership and management, resources issues of financial, HR and technical were the second most significant barrier, and external political obstacles of organizational culture and negative attitudes were the third most significant barriers. It is recommended that awareness of environmental issues in the oil sector is raised through the provision of effective human resource management along with appropriate financial and technical means.