scholarly journals Burst pressure design of the cargo tank used in a novel large subsea freight-glider

2021 ◽  
Vol 1201 (1) ◽  
pp. 012014
Author(s):  
Y. Xing
Keyword(s):  
Average Energy ◽  
Design Parameters ◽  
Burst Pressure ◽  
Safety Margins ◽  
Weight One ◽  
Reliability Methods ◽  
Average Energy Consumption ◽  
The University ◽  
Neutrally Buoyant ◽  
Different Parts

Abstract This paper presents the burst pressure design of the cargo tank used in the University of Stavanger (UiS) Subsea Freight-Glider (USFG). The USFG is an innovative large underwater cargo glider drone that is 50 m long and has a DWT of 1500 ton. It uses variable-buoyancy propulsion instead of traditional propellers for movement. This is an extremely efficient propulsion method and allows the USFG to achieve an average energy consumption of less than 10 kW. Structural weight is a premium as the USFG is required to be neutrally buoyant in water. Therefore, the design of the cargo tank which is the largest component in the USFG needs to be optimal for minimal structural weight. One approach used in design optimisation is to utilise design codes and/or methods that are more precise and therefore allow for lower safety margins. This approach will be investigated in this paper for the burst pressure design of the cargo tank. The different parts of ASME BPVC codes will be compared. The sensitivity of the codes to changes in design parameters is also investigated. Lastly, some comments on the use of reliability methods to further optimise the design are also presented.

scholarly journals Modifying Building Energy-Saving Design Based on Field Research into Climate Features and Local Residents’ Habits

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 442
Author(s):  
Xiaoyue Zhu ◽  
Bo Gao ◽  
Xudong Yang ◽  
Zhong Yu ◽  
Ji Ni
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Residential Buildings ◽  
Average Energy ◽  
Field Tests ◽  
Building Energy ◽  
Building Energy Efficiency ◽  
Local Conditions ◽  
Building Energy Saving ◽  
Average Energy Consumption

In China, a surging urbanization highlights the significance of building energy conservation. However, most building energy-saving schemes are designed solely in compliance with prescriptive codes and lack consideration of the local situations, resulting in an unsatisfactory effect and a waste of funds. Moreover, the actual effect of the design has yet to be thoroughly verified through field tests. In this study, a method of modifying conventional building energy-saving design based on research into the local climate and residents’ living habits was proposed, and residential buildings in Panzhihua, China were selected for trial. Further, the modification scheme was implemented in an actual project with its effect verified by field tests. Research grasps the precise climate features of Panzhihua, which was previously not provided, and concludes that Panzhihua is a hot summer and warm winter zone. Accordingly, the original internal insulation was canceled, and the shading performance of the windows was strengthened instead. Test results suggest that the consequent change of SET* does not exceed 0.5 °C, whereas variations in the energy consumption depend on the room orientation. For rooms receiving less solar radiation, the average energy consumption increased by approximately 20%, whereas for rooms with a severe western exposure, the average energy consumption decreased by approximately 11%. On the other hand, the cost savings of removing the insulation layer are estimated at 177 million RMB (1 USD ≈ 6.5 RMB) per year. In conclusion, the research-based modification method proposed in this study can be an effective tool for improving building energy efficiency adapted to local conditions.

scholarly journals Energy-Efficient and Disjoint Multipath Using Face routing in Wireless Sensor Networks

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7823
Author(s):  
Hyunchong Cho ◽  
Seungmin Oh ◽  
Yongje Shin ◽  
Euisin Lee
Keyword(s):  
Energy Consumption ◽  
Average Energy ◽  
Packet Transmission ◽  
Destination Node ◽  
Path Generation ◽  
Data Packets ◽  
Hole Area ◽  
Face Routing ◽  
Multiple Routes ◽  
Average Energy Consumption

In WSNs, multipath is well-known as a method to improve the reliability of packet delivery by making multiple routes from a source node to a destination node. To improve reliability and load-balancing, it is important to ensure that disjoint characteristics of multipath do not use same nodes during path generation. However, when multipath studies encounter a hole area from which is hard to transmit data packets, they have a problem with breaking the disjoint features of multipath. Although existing studies propose various strategies to bypass hole areas, they have side effects that significantly accelerate energy consumption and packet transmission delay. Therefore, to retain the disjoint feature of multipath, we propose a new scheme that can reduce delay and energy consumption for a node near a hole area using two approaches—global joint avoidance and local avoidance. This scheme uses global joint avoidance to generate a new path centered on a hole area and effectively bypasses the hole area. This scheme also uses local joint avoidance that does not select the same nodes during new path generation using a marking process. In simulations, the proposed scheme has an average 30% improvement in terms of average energy consumption and delay time compared to other studies.

scholarly journals Food security of paddy farm households based on the proportion of food expenditure and energy consumption level in Jogorogo Ngawi

2021 ◽  
Vol 905 (1) ◽  
pp. 012077
Author(s):  
A D P M Larasati ◽  
Darsono ◽  
S Marwanti
Keyword(s):  
Food Security ◽  
Energy Consumption ◽  
Sample Selection ◽  
Average Energy ◽  
Farm Households ◽  
Household Food Security ◽  
Protein Consumption ◽  
Consumption Level ◽  
Food Expenditure ◽  
Average Energy Consumption

Abstract Ngawi is the sixth paddy producer in Indonesia and certainly has an influence on the food security of paddy farm households. This study aimed to analyze the proportion of food expenditure (PFE), energy and protein consumption, the relationship between food expenditure and energy consumption, and the condition of food security. The basic method used descriptive analytic. The number of respondents based on the slovin formula was 87 households. The sample selection used stratified random sampling. The data analysis method used correlation with SPSS 22 and cross indicator between PFE and energy consumption level. The results showed that the average of PFE was 58.81%. The average energy consumption was 4,272.2 kcal/household/day with an energy consumption level of 81.93% while the average protein consumption was 122.1 grams/household/day lower than the average household RDA consumption. Food expenditure had a significant relationship to energy consumption with a correlation coefficient of 0.925 including a very strong and unidirectional relationship. The contribution of household food security conditions were 28.7% secure; 32.2% vulnerable; 10.3% less secure; 28.8% insecure.

Evaluation of the Potential of Fruit Peel Biomass after Conventional and Microwave Drying for Use as Solid Fuel

2015 ◽  
Vol 798 ◽  
pp. 480-485 ◽  
Author(s):  
Andrea Teixeira Charbel ◽  
Bernardo Damázio Trinchero ◽  
Diego Dornas Morais ◽  
Henrique Mesquita ◽  
Viviane Santos Birchal
Keyword(s):  
Fossil Fuels ◽  
Average Energy ◽  
Correlation Coefficients ◽  
Passion Fruit ◽  
Microwave Drying ◽  
Fruit Peel ◽  
Conventional Drying ◽  
Pulp Processing ◽  
Average Energy Consumption ◽  
Time Required

Searching for new sources of energy in order to minimize the dependence on fossil fuels and also to preserve the environmentmeets thenecessityfor finding effective solutions to the problem of waste generated in different production levels.In juice pulp processing industrylarge volumes of waste are produced daily and can contribute, with its burning, for energy production. Once it is necessary the removal of moisture from the residue, this study evaluate the conventional drying and microwave drying of the biomass generated by peels of orange, mango and passion fruit with initial mean moisture content higher than 75%. The experiments were performed in oven at a temperature of 150°C and the average time for an almost complete withdrawal of peels studied was 130min. For drying by microwave with power of 900W, the average time required for the total reduction in moisture was 8.5min. The drying Page model was adjusted by non-linear regression to data obtained with correlation coefficients in all cases greater than 0.955. The higher heating value was rated equal to 16,25kJ/g, 19,62kJ/g, 16,35kJ/g for the peels of orange, mango and passion fruit, respectively. The average energy consumption for the drying process in the oven was 81,25kJ/gevaporated water and 12,07 kJ/gevaporatedwaterin the process by microwave, which indicates that drying using microwave is a very interesting option.

James Cossar Ewart, 1851 - 1933

1934 ◽  
Vol 1 (3) ◽  
pp. 189-195 ◽  
Keyword(s):  
Medical Student ◽  
Bacillus Anthracis ◽  
Gold Medal ◽  
Zoological Museum ◽  
Original Research ◽  
University Of Edinburgh ◽  
Umbilical Arteries ◽  
The University ◽  
Native Place ◽  
Different Parts

James Gossar Ewart, the younger son of John Ewart, of Penicuik, Midlothian, was born in November, 1851. He passed his boyhood at his native place and received his early education there. At the age of 19 he matriculated in the University of Edinburgh as a medical student, and graduated as Bachelor of Medicine and Master of Surgery in 1874. He was then appointed Demonstrator of Anatomy under Turner, but shortly afterwards he migrated to London, becoming Curator of the Zoological Museum at University College. In order to learn his work the more thoroughly he visited various continental museums and worked for a time at Strassburg in 1876. In London he occupied himself by making preparations for the Museum at the College, showing a great proficiency, and in addition he assisted Lankester, who held the Professorship of Zoology in organizing and conducting the practical classes which were then instituted. He also began to do original research, his earlier papers being upon the structure of different parts of the eye, upon the anatomy of the lamprey (in which he investigated the vascular peribranchial spaces, the valves of the umbilical arteries and certain of the sexual organs) and upon the placentation and fecundity of the Shanghai River deer. Other work which he did in London was upon certain bacterial organisms and he was awarded a gold medal for a thesis, on Bacillus anthracis, presented for the degree of M.D. at Edinburgh.

Multidisciplinary Integration and Robustness Evaluation Applied to Low Pressure Turbine Casing Design

2006 ◽  
Author(s):  
Gian Paolo De Poli ◽  
Carlo Frola ◽  
Massimo Gallizio ◽  
Luca Fattore ◽  
Massimiliano Mattone
Keyword(s):  
Robust Design ◽  
Monte Carlo Analysis ◽  
Design Parameters ◽  
Property Variation ◽  
Low Pressure Turbine ◽  
Turbine Casing ◽  
Reliability Methods ◽  
Critical Location ◽  
And Performance ◽  
Geometrical Dimensions

In modern aerospace engineering design context one of the most important task is managing and simulate properly the effect of uncertainties on the response and performance of the system. In fact real engineering problems are characterised by random variations of material property, variation of loading conditions, manufacturing tolerances, etc. Different approaches have been developed by the research community to address uncertainties; while reliability methods primarily deal with probability of constraint satisfaction or violation, robust design methods have focused on the variation of system responses due to design parameters random variation. In this paper a robust design (RD) analysis of gas-turbine casing is performed in order to estimate how much uncertainties affect the life of the component. The RD analysis is performed in a multidisciplinary environment since the casing is subjected to thermo-mechanical loads. First thermal steady-state analysis has been performed changing randomly the boundary conditions (heat transfer coefficient and air temperature) and the temperature distribution on the casing is calculated. Then the structural analysis is performed changing geometrical dimensions on the base of defined tolerances and process capability. The result of the Monte Carlo analysis is a statistic distribution of the stress in the critical locations. This information is used to estimate the statistic distribution of the life in each critical location. The obtained result consents to evaluate the risk that some critical location exceeds the life margin limit.

scholarly journals Modeling of Duty-Cycled MAC Protocols for Heterogeneous WSN with Priorities

Electronics ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 467 ◽  
Author(s):  
Canek Portillo ◽  
Jorge Martinez-Bauset ◽  
Vicent Pla ◽  
Vicente Casares-Giner
Keyword(s):  
Performance Evaluation ◽  
Energy Consumption ◽  
Average Energy ◽  
Packet Delay ◽  
Evaluation Study ◽  
Duty Cycling ◽  
Quantitative Evidence ◽  
And Performance ◽  
Save Energy ◽  
Average Energy Consumption

Wireless Sensor Networks (WSN) have experienced an important revitalization, particularly with the arrival of Internet of Things applications. In a general sense, a WSN can be composed of different classes of nodes, having different characteristics or requirements (heterogeneity). Duty-cycling is a popular technique used in WSN, that allows nodes to sleep and wake up periodically in order to save energy. We believe that the modeling and performance evaluation of heterogeneous WSN with priorities operating in duty-cycling, being of capital importance for their correct design and successful deployment, have not been sufficiently explored. The present work presents a performance evaluation study of a WSN with these features. For a scenario with two classes of nodes composing the network, each with a different channel access priority, an approximate analytical model is developed with a pair of two-dimensional discrete-time Markov chains. Note that the same modeling approach can be used to analyze networks with a larger number of classes. Performance parameters such as average packet delay, throughput and average energy consumption are obtained. Analytical results are validated by simulation, showing accurate results. Furthermore, a new procedure to determine the energy consumption of nodes is proposed that significantly improves the accuracy of previous proposals. We provide quantitative evidence showing that the energy consumption accuracy improvement can be up to two orders of magnitude.

Thermal Performance of Electrochromic Smart Window with Nanocomposite Structure under Different Climates in Iran

2019 ◽  
Vol 11 (2) ◽  
pp. 154-164 ◽  
Author(s):  
Siamak Hoseinzadeh
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Average Energy ◽  
Climatic Conditions ◽  
Smart Window ◽  
Nanocomposite Layer ◽  
Energy Plus ◽  
Average Energy Consumption ◽  
Bandar Abbas ◽  
Different Climates

Objective: This study investigated the optimization of thermal energy consumption using electrochromic components with a new nanocomposite layer (WO3+Ag) in a larger size (window) for a room with an educational application for five cities with different climatic conditions in Iran (Yazd, Tehran, Bandar Abbas, Tabriz, and Sari). Materials & Methods: For this simulation platform, the software was implemented in Energy Plus. This feasibility study was modeled by DesignBuilder software which reported reduced thermal energy consumption across all climates in Iran (hot and dry, warm and semi-humid, warm and wet, moderate and dry, and mild and humid.). Four strategies were considered for better comparison. The first strategy used for common double-glazed windows, while the second to fourth strategies involved the use of the electrochromic window in three different modes; bleached mode (Off), colored mode (On), and switchable mode (controlled below comfort conditions). Results: The third and fourth strategies indicated a reduction in thermal energy consumption in different climates from 25 to 45% relative to typical windows. The best result of cooling energy consumption was observed in Tehran. Conclusion: For this climate, the average energy consumption dropped to 34% for the warm months of the year and even 42% for the warmest month of the year (August).

The use and potential use of reliability engineering for offshore structures

1988 ◽  
Vol 92 (911) ◽  
pp. 9
Author(s):  
G. A. Mowatt ◽  
D. J. Loader ◽  
C. H. Arbuthnot
Keyword(s):  
Offshore Structures ◽  
Current Status ◽  
Design Stage ◽  
Design Parameters ◽  
Reliability Engineering ◽  
Codes Of Practice ◽  
Offshore Oil Production ◽  
Reliability Methods ◽  
Offshore Oil ◽  
Potential Use

This paper presents a review of the current status and potential future use of reliability methods in the design, fabrication and operation of offshore oil production platforms. An overview of the traditional design process is presented and key areas where reliability methods have contributed to the development of codes of practice are described. Future applications in the design stage include the optimisation of framing configurations and the treatment of uncertainties in basic design parameters.

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