• Tall Buildings: The New Space Race: Introduction

      Georgopoulos, C.; Lam, Dennis (2010)
    • Tangential slip noise of V-ribbed belts

      Dalgarno, K.W.; Moore, R.B.; Day, Andrew J. (1999)
      This paper reports the results of a study into V-ribbed belt noise generated as a result of tangential belt slip. The results of experimental studies to identify the belt operating conditions associated with belt noise are presented, together with the results of analytical studies to identify the mechanism of noise generation. It is concluded that tangential slip V-ribbed belt noise generation is controlled only by the amount of slip, and that the mechanism of noise generation is harmonic excitation of the fundamental vibration mode of the belt, with stick¿slip frictional behaviour providing the impetus for the vibration
    • Tattoo ink nanoparticles in skin tissue and fibroblasts

      Grant, Colin A.; Twigg, Peter C.; Baker, Richard; Tobin, Desmond J. (2015-05-20)
      Tattooing has long been practised in various societies all around the world and is becoming increasingly common and widespread in the West. Tattoo ink suspensions unquestionably contain pigments composed of nanoparticles, i.e., particles of sub-100 nm dimensions. It is widely acknowledged that nanoparticles have higher levels of chemical activity than their larger particle equivalents. However, assessment of the toxicity of tattoo inks has been the subject of little research and ink manufacturers are not obliged to disclose the exact composition of their products. This study examines tattoo ink particles in two fundamental skin components at the nanometre level. We use atomic force microscopy and light microscopy to examine cryosections of tattooed skin, exploring the collagen fibril networks in the dermis that contain ink nanoparticles. Further, we culture fibroblasts in diluted tattoo ink to explore both the immediate impact of ink pigment on cell viability and also to observe the interaction between particles and the cells.
    • Teaching Creative Digital Hardware Design

      Zainee, N.B.M.; Noras, James M. (2013)
      Engineering undergraduates not only need to learn facts, but also how to be creative in the open-ended situations they will encounter in their professional careers. Our final year Honours module gives students a grounding in digital systems design, mainly using VLSI for design entry and simulation. The second half of our module is a design exercise, which has straightforward aspects, but which allows motivated students to undertake progressively open-ended investigations. Our educational framework is guided by recommendations of professional bodies promoting excellence and encouragement of creativity in engineering development. (C) 2013 The Authors. Published by Elsevier Ltd.
    • Technology demonstrator of a novel software defined radio-based aeronautical communications system

      Cheng, Yongqiang; Xu, Kai J.; Hu, Yim Fun; Pillai, Prashant; Baddoo, J.; Smith, A.; Ali, Muhammad; Pillai, Anju (2014-11)
      This paper presents the architectural design, software implementation, the validation and flight trial results of an aeronautical communications system developed within the Seamless Aeronautical Networking through integration of Data links Radios and Antennas (SANDRA) project funded by the European 7th Framework Aeronautics and Transport Programme. Based on Software Defined Radio (SDR) techniques, an Integrated Modular Radio (IMR) platform was developed to accommodate several radio technologies. This can drastically reduce the size, weight and cost in avionics with respect to current radio systems implemented as standalone equipment. In addition, the modular approach ensures the possibility to dynamically reconfigure each radio element to operate on a specific type of radio link. A radio resource management (RRM) framework is developed in the IMR consisting of a communication manager for the resource allocation and management of the different radio links and a radio adaptation manager to ensure protocol convergence through IP. The IMR has been validated though flight trials held at Oberpfaffenhofen, Germany in June 2013. The results presented in the paper validate the flexibility and scalability of the IMR platform and demonstrate seamless service coverage across different airspace domains through interworking between the IMR and other components of the SANDRA network.
    • Technology impact on agricultural productivity: a review of precision agriculture using unmanned aerial vehicles

      Abdullahi, H.S.; Mahieddine, F.; Sheriff, Ray E. (2015)
      Technology application to agricultural productivity is thought to be the solution to meet food demand of the growing population. In a rapidly changing world, with the prospect of decreasing arable land due to urbanization and industrialization, agricultural output requires a 70 % increase in production levels and efficient growth in the harvesting, distribution and consumption of the resources, to meet demand. There are innovations in Information and Communications Technology that can be applied to the agricultural sector in areas of precision farming, use of farm management software, wireless sensors, and use of agricultural machinery. Remote sensing technology is playing a key role through precision agriculture. This paper highlights ways in which precision agriculture is impacting on agriculture with the use of unmanned aerial vehicles for image capturing, processing and analysis.
    • Telecommunication Network Security

      Adeka, Muhammad I.; Shepherd, Simon J.; Abd-Alhameed, Raed A. (2015)
      Our global age is practically defined by the ubiquity of the Internet; the worldwide interconnection of cyber networks that facilitates accessibility to virtually all ICT and other elements of critical infrastructural facilities, with a click of a button. This is regardless of the user’s location and state of equilibrium; whether static or mobile. However, such interconnectivity is not without security consequences. A telecommunication system is indeed a communication system with the distinguishing key word, the Greek tele-, which means "at a distance," to imply that the source and sink of the system are at some distance apart. Its purpose is to transfer information from some source to a distant user; the key concepts being information, transmission and distance. These would require a means, each, to send, convey and receive the information with safety and some degree of fidelity that is acceptable to both the source and the sink. Chapter K begins with an effort to conceptualise the telecommunication network security environment, using relevant ITU-T2* recommendations and terminologies for secure telecommunications. The chapter is primarily concerned with the security aspect of computer-mediated telecommunications. Telecommunications should not be seen as an isolated phenomenon; it is a critical resource for the functioning of cross-industrial businesses in connection with IT. Hence, just as information, data or a computer/local computer-based network must have appropriate level of security, so also a telecommunication network must have equivalent security measures; these may often be the same as or similar to those for other ICT resources, e.g., password management. In view of the forgoing, the chapter provides a brief coverage of the subject matter by first assessing the context of security and the threat-scape. This is followed by an assessment of telecommunication network security requirements; identification of threats to the systems, the conceivable counter or mitigating measures and their implementation techniques. These bring into focus various cryptographic/crypt analytical concepts, vis a vis social engineering/socio-crypt analytical techniques and password management. The chapter noted that the human factor is the most critical factor in the security system for at least three possible reasons; it is the weakest link, the only factor that exercises initiatives, as well as the factor that transcends all the other elements of the entire system. This underscores the significance of social 2*International Telecommunications Union - Telecommunication Standardisation Sector 12 engineering in every facet of security arrangement. It is also noted that password security could be enhanced, if a balance is struck between having enough rules to maintain good security and not having too many rules that would compel users to take evasive actions which would, in turn, compromise security. The chapter is of the view that network security is inversely proportional to its complexity. In addition to the traditional authentication techniques, the chapter gives a reasonable attention to locationbased authentication. The chapter concludes that security solutions have a technological component, but security is fundamentally a people problem. This is because a security system is only as strong as its weakest link, while the weakest link of any security system is the human infrastructure. A projection for the future of telecommunication network security postulates that, network security would continue to get worse unless there is a change in the prevailing practice of externality or vicarious liability in the computer/security industry; where consumers of security products, as opposed to producers, bear the cost of security ineffectiveness. It is suggested that all transmission devices be made GPS-compliant, with inherent capabilities for location-based mutual authentication. This could enhance the future of telecommunication security.
    • Temperature dependent stiffness and visco-elastic behaviour of lipid coated microbubbles using atomic force microscopy.

      Grant, Colin A.; McKendry, J.E.; Evans, S.D. (03/11/2011)
      The compression stiffness of a phospholipid microbubble was determined using force-spectroscopy as a function of temperature. The stiffness was found to decrease by approximately a factor of three from 0.08 N m 1, at 10 C, down to 0.03 N m 1 at 37 C. This temperature dependence indicates that the surface tension of lipid coating is the dominant contribution to the microbubble stiffness. The timedependent material properties, e.g. creep, increased non-linearly with temperature, showing a factor of two increase in creep-displacement, from 24 nm, at 10 C, to 50 nm, at 37 C. The standard linear solid model was used to extract the visco-elastic parameters and their determination at different temperatures allowed the first determination of the activation energy for creep, for a microbubble, to be determined.
    • Tensile Deformation of Oriented Poly(ε-caprolactone) and Its Miscible Blends with Poly(vinyl methyl ether)

      Jiang, Z.; Wang, Y.; Fu, L.; Whiteside, Benjamin R.; Wyborn, John; Norris, Keith; Wu, Z.; Coates, Philip D.; Men, Y. (2013-09-10)
      The structural evolution of micromolded poly(ε-caprolactone) (PCL) and its miscible blends with noncrystallizable poly(vinyl methyl ether) (PVME) at the nanoscale was investigated as a function of deformation ratio and blend composition using in situ synchrotron smallangle X-ray scattering (SAXS) and scanning SAXS techniques. It was found that the deformation mechanism of the oriented samples shows a general scheme for the process of tensile deformation: crystal block slips within the lamellae occur at small deformations followed by a stressinduced fragmentation and recrystallization process along the drawing direction at a critical strain where the average thickness of the crystalline lamellae remains essentially constant during stretching. The value of the critical strain depends on the amount of the amorphous component incorporated in the blends, which could be traced back to the lower modulus of the entangled amorphous phase and, therefore, the reduced network stress acting on the crystallites upon addition of PVME. When stretching beyond the critical strain the slippage of the fibrils (stacks of newly formed lamellae) past each other takes place resulting in a relaxation of stretched interlamellar amorphous chains. Because of deformation-induced introduction of the amorphous PVME into the interfibrillar regions in the highly oriented blends, the interactions between fibrils becomes stronger upon further deformation and thus impeding sliding of the fibrils to some extent leading finally to less contraction of the interlamellar amorphous layers compared to the pure PCL
    • Tensile, rheological and morphological characterizations of multi-walled carbon nanotube/polypropylene composites prepared by microinjection and compression molding

      Ezat, G.S.; Kelly, Adrian L.; Youseffi, Mansour; Coates, Philip D. (2022-03)
      Polypropylene (PP) reinforced with 2 and 4 wt% of multi-walled carbon nanotubes (MWNT) were melt-blended in twin screw extruder and then molded by compression or micromolding process. The impact of injection speed on the surface morphology, rheological and tensile characteristics was investigated by using a scanning electron microscope, parallel plate rheometry, and tensiometry. Results showed that the tensile properties of micro-molded specimens were remarkably higher than those of the compression molded sheets. Compared to compression molded sheets, micromolded specimens demonstrated up to 40 and 244% higher tensile stiffness and yield strength, respectively, most likely due to the alignment of polymer chain segments in the flow direction induced during the micromolding process. It was observed that the fast filling speed caused a drop in the tensile properties of the nanocomposites and polymer. Rheological examination revealed that the presence of a rheological percolation network in the nanocomposites produced by micromolding and the fast injection speed was beneficial for establishing the percolated network. Morphological examination revealed that the size of nanotube agglomerations that appeared in micromolded specimens was up to five times smaller than in compression molded sheets and the agglomeration size decreased with the increase of the injection speed.
    • Test data generation from UML state machine diagrams using GAs

      Doungsa-ard, Chartchai; Dahal, Keshav P.; Hossain, M. Alamgir; Suwannasart, T. (2008)
      Automatic test data generation helps testers to validate software against user requirements more easily. Test data can be generated from many sources; for example, experience of testers, source program, or software specification. Selecting a proper test data set is a decision making task. Testers have to decide what test data that they should use, and a heuristic technique is needed to solve this problem automatically. In this paper, we propose a framework for generating test data from software specifications. The selected specification is Unified Modeling Language (UML) state machine diagram. UML state machine diagram describes a system in term of state which can be changed when there is an action occurring in the system. The generated test data is a sequence of these actions. These sequences of action help testers to know how they should test the system. The quality of generated test data is measured by the number of transitions which is fired using the test data. The more transitions test data can fire, the better quality of test data is. The number of coverage transitions is also used as a feedback for a heuristic search for a better test set. Genetic algorithms (GAs) are selected for searching the best test data. Our experimental results show that the proposed GA-based approach can work well for generating test data for some types of UML state machine diagrams.
    • Test on 15m Span Composite Cellular Beam.

      Lawson, M.; Aggelopoulos, E.S.; Lam, Dennis (2014)
      Cellular beams are the preferred form of long span construction in multi-storey buildings. For efficient design of composite cellular beams, asymmetric sections are often manufactured in which the bottom flange is larger than the top flange. A further innovation is in the use of 80mm deep deck profiles which allows beam spacing to be increased to 4.5m, and so the effective slab width acting compositely with the long span beams is also increased. The values for shear connector (stud) resistance given in Eurocode 4 (EN 1994-1-1), when used in combination with these modern decking profiles, have led to problems in achieving the minimum degree of shear connection for composite beams in comparison to the former BS 5950-3. For secondary beams, the number of shear connectors that can be accommodated in a span is limited by the spacing of the deck ribs (typically 300mm for deep trapezoidal profiles), and it is found that even for pairs of shear connectors per deck rib, it is impossible to satisfy the shear connection rules in Eurocode 4 for long span asymmetric beams. SCI, with support from the Research Fund for Coal and Steel, is on the way to resolving this problem in design to Eurocode 4, and has completed a test on a 15.3m composite cellular beam at the University of Bradford. This is believed to be the longest composite cellular beam test ever carried out. The test was part-sponsored by ASD Westok.
    • Testing and analysis of concrete-filled elliptical hollow sections

      Yang, H.; Lam, Dennis; Gardner, L. (2008)
      Concrete-filled steel tubes are gaining increasing prominence in a variety of engineering structures, with the principal cross-section shapes being square, rectangular and circular hollow sections. A recent addition to this range has been that of elliptical hollow sections. The structural response of empty elliptical tubes has been examined in previous studies. In this paper, the cross-sectional axial behaviour of concrete-filled elliptical hollow sections is investigated. An experimental programme comprising a total of 21 test specimens, with three nominal tube thicknesses (4 mm, 5 mm and 6.3 mm) and three concrete grades (C30, C60 and C100) has been performed. The effects of steel tube thickness, concrete strength and constraining factor on elastic stiffness, ductility and ultimate strength were studied. To simulate the effects of concrete shrinkage, the inner surfaces of 6 of the 21 test specimens were coated with grease prior to casting. To investigate confinement effects, a further 6 of the 21 test specimens were loaded through the concrete core only. The results of the tests presented herein were combined with those from previous studies, and compared with existing design provisions for square, rectangular and circular concrete-filled tubes. The design expressions from current European, North American, Japanese, British and Chinese Standards were assessed. On the basis of the comparisons, design recommendations for concrete-filled elliptical hollow sections have been made.
    • Testing Based on Identifiable P Systems Using Cover Automata and X-Machines

      Gheorghe, Marian; Ipate, F.; Konur, Savas (2016-12-01)
      This paper represents a significant advance on the issue of testing for implementations specified by P systems with transformation and communicating rules. Using the X-machine framework and the concept of cover automaton, it devises a testing approach for such systems, that, under well defined conditions, it ensures that the implementation conforms to the specification. It also investigates the issue of identifiability for P systems, that is an essential prerequisite for testing implementations based on such specifications and establishes a fundamental set of properties for identifiable P systems.
    • Testing of a Full-Scale Composite Floor Plate

      Lam, Dennis; Dai, Xianghe; Sheehan, Therese (2019-04)
      A full-scale composite floor plate was tested to investigate the flexural behavior and in-plane effects of the floor slab in a grillage of composite beams that reduces the tendency for longitudinal splitting of the concrete slab along the line of the primary beams. This is important in cases where the steel decking is discontinuous when it is orientated parallel to the beams. In this case, it is important to demonstrate that the amount of transverse reinforcement required to transfer local forces from the shear connectors can be reduced relative to the requirements of Eurocode 4. The mechanism under study involved in-plane compression forces being developed in the slab due to the restraining action of the floor plate, which was held in position by the peripheral composite beams; while the secondary beams acted as transverse ties to resist the forces in the floor plate that would otherwise lead to splitting of the slab along the line of the primary beams. The tendency for cracking along the center line of the primary beam and at the peripheral beams was closely monitored. This is the first large floor plate test that has been carried out under laboratory conditions since the Cardington tests in the early 1990s, although those tests were not carried out to failure. This floor plate test was designed so that the longitudinal force transferred by the primary beams was relatively high (i.e., it was designed for full shear connection), but the transverse reinforcement was taken as the minimum of 0.2% of the concrete area. The test confirmed that the primary beams reached their plastic bending resistance despite the discontinuous decking and transverse reinforcement at the minimum percentage given in Eurocode 4. Based on this test, a reduction factor due to shear connectors at edge beams without U-bars is proposed.
    • Testing of composite beam with demountable shear connectors

      Rehman, Naveed; Lam, Dennis; Dai, Xianghe; Ashour, Ashraf F. (2018-01)
      This paper presents an experimental study on an innovative composite floor system that can be demounted and deconstructed. In this system, the composite slab, formed with profiled metal decking, was connected to a steel beam via demountable shear connectors. A full-scale demountable composite floor system specimen was tested to ultimate load bearing capacity and compared with a similar non-demountable composite floor system specimen using conventional welded headed stud connectors. The experimental results and observations showed that the structural behaviour and load bearing capacity of both composite floor systems are very similar. However, the composite floor system with demountable shear connectors could be deconstructed after testing and the composite slab could be easily detached from the steel beam. The comparison and analysis presented in this paper indicated that the simple design methods currently provided in the Eurocode 4 for the welded shear connections could be used to assess the ultimate moment capacity of demountable composite floor systems.
    • Tests of concrete flanged beams reinforced with CFRP bars.

      Ashour, Ashraf F.; Family, M. (2006-11)
      Tests results of three flanged and two rectangular cross-section concrete beams reinforced with carbon fibre reinforced polymer (CFRP) bars are reported. In addition, a companion concrete flanged beam reinforced with steel bars is tested for comparison purposes. The amount of CFRP reinforcement used and flange thickness were the main parameters investigated in the test specimens. One CFRP reinforced concrete rectangular beam exhibited concrete crushing failure mode, whereas the other four CFRP reinforced concrete beams failed due to tensile rupture of CFRP bars. The ACI 440 design guide for FRP reinforced concrete members underestimated the moment capacity of beams failed due to CFRP tensile rupture and reasonably predicted deflections of the beams tested. A simplified theoretical analysis for estimating the moment capacity of concrete flanged beams reinforced with FRP bars was developed. The experimental moment capacity of the CFRP reinforced concrete beams tested compared favourably with that predicted by the theoretical analysis developed.
    • Tests of continuous concrete slabs reinforced with basalt fibre reinforced plastic bars

      Kara, Ilker F.; Köroğlu, Mehmet A.; Ashour, Ashraf F. (2017)
      This paper presents experimental results of three continuously supported concrete slabs reinforced with basalt-fibre-reinforced polymer (BFRP) bars. Three different BFRP reinforcement combinations of over and under reinforcement ratios were applied at the top and bottom layers of continuous concrete slabs tested. One additional concrete continuous slab reinforced with steel bars and two simply supported slabs reinforced with under and over BFRP reinforcements were also tested for comparison purposes. All slabs sections tested had the same width and depth but different amounts of BFRP reinforcement. The experimental results were used to validate the existing design guidance for the predictions of moment and shear capacities, and deflections of continuous concrete elements reinforced with BFRP bars. The continuously supported BFRP reinforced concrete slabs illustrated wider cracks and larger deflections than the control steel reinforced concrete slab. All continuous BFRP reinforced concrete slabs exhibited a combined shear–flexure failure mode. ACI 440-1R-15 equations give reasonable predictions for the deflections of continuous slabs (after first cracking) but stiffer behaviour for the simply supported slabs, whereas CNR DT203 reasonably predicted the deflections of all BFRP slabs tested. On the other hand, ISIS-M03-07 provided the most accurate shear capacity prediction for continuously supported BFRP reinforced concrete slabs among the current shear design equations.