2,746 research outputs found

    Investigating the Behavior of Offshore Platform to Ship Impact

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    Offshore platform structure has the ability to resist wave loading, wind loading, operation loading, and ship collision, therefore, it is important to investigate the structural behavior of platform taking into consideration soil-structure-pile interaction when the platform is subjected to ship impact at a different location on deck slab. The present study deals with platform supported by pile foundation. The effect of soil-pile interaction on behavior of platform to lateral impact load is investigated by using finite element simulation which is performed by ABAQUS software. From the results obtained, it is obvious that the ship collision position on platform will be reflected on ultimate capacity of structure so the structure will undergo to loose ultimate capacity due to damage that occurs from the ship collision. This study comprises investigation of pile lateral displacement, pile twist angle, pile shear force distribution, pile bending moment distribution and deck slab displacement. It also clarifies that the pile displacement has been reflected on pile critical length. The twist angle of the pile is more sensitive to soil type and loading condition. It is seems that the shear force distribution and bending moment distribution are affected by loading condition and soil type. Finally this study shows that the response of deck slab depends on soil type, soil-pile interaction and loading condition

    EAST: Energy Efficient Adaptive Scheme for Transmission in Wireless Sensor Networks

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    In this paper, we propose Energy-efficient Adaptive Scheme for Transmission (EAST) in WSNs. EAST is IEEE 802.15.4 standard compliant. In this approach, open-loop is used for temperature-aware link quality estimation and compensation. Whereas, closed-loop feedback helps to divide network into three logical regions to minimize overhead of control packets on basis of Threshold transmitter power loss (RSSIloss) for each region and current number of neighbor nodes that help to adapt transmit power according to link quality changes due to temperature variation. Simulation results show that propose scheme; EAST effectively adapts transmission power to changing link quality with less control packets overhead and energy consumption compared to classical approach with single region in which maximum transmitter power assigned to compensate temperature variation

    Simulation Analysis of Medium Access Techniques

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    This paper presents comparison of Access Techniques used in Medium Access Control (MAC) protocol for Wireless Body Area Networks (WBANs). Comparison is performed between Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), Pure ALOHA and Slotted ALOHA (S-ALOHA). Performance metrics used for comparison are throughput (T), delay (D) and offered load (G). The main goal for comparison is to show which technique gives highest Throughput and lowest Delay with increase in Load. Energy efficiency is major issue in WBAN that is why there is need to know which technique performs best for energy conservation and also gives minimum delay.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Com- munication and Applications (BWCCA 2012), Victoria, Canada, 201

    The Overshot Gate as a Flow-Measuring Device

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    The overshot gate is a commonly used adjustable overflow weir for regulating the upstream water level in open channels. The amount of gate movement is proportional to the water level change. However, to effectively manage the water flow, it is also important for operators to accurately measure the flow rate in the channel. This study examines an overshot gate installed at the end of a laboratory flume to estimate the flow rate under various free flow conditions. This study investigates different gate angles ranging from 9.6° to 90° to evaluate their impact on the flow properties and the discharge coefficient. The analysis of the results indicates that the maximum flow rate values can be achieved with gate inclinations from 15.5° to 47.2° with relatively lower head; the inclined alignment of the gate decreases the effective gate height which consequently increases the gate efficiency. The use of the overshot gate is advantageous over the normal gate when channel depth is limited and higher discharge is required at relatively lower head. In this study, at the highest gate inclinations, the water surface is significantly stable having the lowest values of the approach Froude number. In addition, the head to gate height ratio decreases with raising the gate due to the reduced vertical contraction of the channel. Finally, this paper proposes an empirical equation for estimating the discharge coefficient based on the gate inclination, which demonstrates good accuracy in the specified range

    Going Beyond Equations With Disciplinary Thinking In First-Year Physics

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    Students in first-year physics courses generally focus on hunting for suitable equations and formulas when tackling a variety of physical situations and physics problems. There is a need for a framework that can guide them to disciplinary ways of thinking and help them begin to think like physicists. To serve this end, in this study, a framework of disciplinary thinking in physics was presented to the students and incorporated in the delivery of a first-year course on electricity and magnetism for engineering students. The framework consisted of three types of thinking: principle-based thinking (PBT), case-based thinking (CBT), and experiential-intuitive thinking (EIT). The students’ experiences of learning this framework were tracked through weekly reflection reports, which were analyzed using a coding scheme comprised of the following four categories of increasing cognitive complexity for each type of thinking: mentioning the type of thinking learned without elaboration (code A), mentioning the type of thinking learned with elaboration (code B), applying the type of thinking learned (code C) and making meaning of the type of thinking learned (code D). Examples of students’ reflections for these codes for each type of thinking are included. The students most predominantly reflected on PBT followed by CBT with a very few reflections on EIT. Within both PBT and CBT, most reflections fell under the code B.  Overall, the results are encouraging and point to a students’ shift from formula hunting to the thinking framework based strategies

    Estimate and Classify the Hardness of Different Water Sources by Using Prepared Soap Solution

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    This research includes available techniques and simplified methods to estimate and classify the quality of hardness for different water supply sources like sea water, various wells (Fayda, khabyar, jumbyar) and tap water of Basrah ,Mosul, Duhok and Baghdad, by using prepared soap solution from different commercial liquid soap with different concentration (SS1,2,3 , SS4,5,6 , SS7,8,9 ). The hardness of water is relative to the formation of foam (suds) when soap solution is added to water samples until a foam layer of a certain height (2cm) formed. We determine the volume (in drops, milliliter) of soap solution. If there is a lot of foam formed quickly with little soap solution, the water is rather soft. If you need to add a lot of soap solution to produce a certain height of foam, the water is rather hard. Many factor that establish during experiments, the quality of water supply, measuring degree of hardness, concentration of water samples. Compared with the results of laboratory tests for water stations of Mosul gave our method of encouraging and positive results to continue in the future, so liquid soap bubbles (foam) are a good indicator of classifying types of water. Key words: Estimate and classify the hardness of different water sources, New and simple calculations 

    Performance Analysis of Hierarchical Routing Protocols in Wireless Sensor Networks

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    This work focusses on analyzing the optimization strategies of routing protocols with respect to energy utilization of sensor nodes in Wireless Sensor Network (WSNs). Different routing mechanisms have been proposed to address energy optimization problem in sensor nodes. Clustering mechanism is one of the popular WSNs routing mechanisms. In this paper, we first address energy limitation constraints with respect to maximizing network life time using linear programming formulation technique. To check the efficiency of different clustering scheme against modeled constraints, we select four cluster based routing protocols; Low Energy Adaptive Clustering Hierarchy (LEACH), Threshold Sensitive Energy Efficient sensor Network (TEEN), Stable Election Protocol (SEP), and Distributed Energy Efficient Clustering (DEEC). To validate our mathematical framework, we perform analytical simulations in MATLAB by choosing number of alive nodes, number of dead nodes, number of packets and number of CHs, as performance metrics.Comment: NGWMN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201

    The effects of poverty and prison on British Muslim men who offend

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    © 2018 by the author. Focusing on the lives of British Muslim young men, this article examines the links between their social and economic relations and their prison experiences, desistance, and identity. In understanding the meanings they place on their prison experiences and their social and economic marginalization, the article theorises about social integration, and their place in British society. An intergenerational shift from the availability of local high-waged, skilled, and secure textile work to low-waged, precarious, service work presented them with a series of problems and opportunities, leading them to reject licit wage labour and embrace illicit entrepreneurial criminality. The article concludes that their social and economic relations drove criminal solutions, not ethnicity

    Transmission Delay of Multi-hop Heterogeneous Networks for Medical Applications

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    Nowadays, with increase in ageing population, Health care market keeps growing. There is a need for monitoring of Health issues. Body Area Network consists of wireless sensors attached on or inside human body for monitoring vital Health related problems e.g, Electro Cardiogram (ECG), ElectroEncephalogram (EEG), ElectronyStagmography(ENG) etc. Data is recorded by sensors and is sent towards Health care center. Due to life threatening situations, timely sending of data is essential. For data to reach Health care center, there must be a proper way of sending data through reliable connection and with minimum delay. In this paper transmission delay of different paths, through which data is sent from sensor to Health care center over heterogeneous multi-hop wireless channel is analyzed. Data of medical related diseases is sent through three different paths. In all three paths, data from sensors first reaches ZigBee, which is the common link in all three paths. After ZigBee there are three available networks, through which data is sent. Wireless Local Area Network (WLAN), Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunication System (UMTS) are connected with ZigBee. Each network (WLAN, WiMAX, UMTS) is setup according to environmental conditions, suitability of device and availability of structure for that device. Data from these networks is sent to IP-Cloud, which is further connected to Health care center. Main aim of this paper is to calculate delay of each link in each path over multihop wireless channel.Comment: BioSPAN with 7th IEEE International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA 2012), Victoria, Canada, 201
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