Very limited research studies have been conducted to examine bond of glass fibre reinforced polymer (GFRP) bars with high concrete strength. The current research project aims to compare between bond measured from a pull-out test and a hinged beam test for GFRP bars embedded in high strength concrete. Different parameters influencing bond such as GFRP bar diameter, embedment length and surface configuration were investigated in both test methods, while the bar position, i.e. top or bottom, was only studied in hinged beams. Seventy-two pull-out cubes, eight pull-out prisms and twenty-four hinged beams reinforced with GFRP bars were constructed and tested to failure. Twelve pull-out cubes and four hinged beams reinforced with steel bars were also tested for comparison purposes. The results showed that bond stress – slip curves obtained from various testing methods were similar, consisting of high initial stiffness, followed by nonlinear ascending and softening branches. In addition, it was found that the experimental bond strength obtained from hinged beams was higher than both bond strengths measured by the pull-out cube and pull-out prism. However, when a finite element analysis was conducted for hinged beams, it was shown that the tensile force in the reinforcing bar estimated by equilibrium conditions is overestimated as the large deformation of hinged beams at failure was not considered. Therefore, if the tensile force obtained from the finite element analysis is used to calculate the bond strength, it would be similar to that obtained from pull-out cube and prism. Moreover, it was found that the distribution of tensile and bond stresses was nonlinear along the GFRP embedment length and bond stress at the vicinity of the free end increased with increasing the load due to redistribution of bond stresses along the embedment length. Bond strengths were compared against the prediction methods provided in ACI-440.1R, CSA-S806, CSA-S6 and JSCE 1997. In general, all design codes showed conservative results for all specimens tested and ACI predictions gave a good agreement with experimental data compared to other codes. Artificial neural network models were developed to predict bond strength of GFRP bars in concrete. These models used bar diameter, embedment length, concrete compressive strength and concrete cover as input variables. The developed ANN models showed to be able to predict bond strength of GFRP bars in concrete and, therefore, were used to conduct a parametric study. / Higher Education Institute, Government of Libya

M.Sc. / Research into blood protozoans (haematozoans) infecting African tortoises is scanty with only a few records published, many during the early part of the last century. Little research had been done on the blood parasites of tortoises examined in this study namely, Kinixys lobatsiana, K. belliana belliana, K. natalensis, Geochelone pardalis pardalis, G. pardalis babcocki and Chersina angulata. The study therefore aimed to: 1) examine apicomplexan haematozoan parasites infecting several of South Africa’s indigenous tortoises and compare them with published species descriptions, especially from neighbouring Mozambique; 2) provide host details (identity, ectoparasites, host weight and gender, effects of blood parasites on host cells) and locality records in different seasons for described and new apicomplexan species; 3) describe new and recorded parasites using morphometrics and, if possible, ultrastructural characteristics 4) attempt apicomplexan DNA extraction, amplification and, if feasible, purification; and 5) establish a basis for future research as a result of the acquired knowledge. During the current study, 154 tortoises of six species in three genera, both captive and wild, and from four South African provinces (Gauteng, North West, Kwazulu-Natal and Western Cape) were sampled. Giemsa stained blood smears and use of image analysis enabled morphometric analysis of the apicomplexans and their effects on host cells, while some blood preserved in Karnovsky’s and Todd’s fixatives received detailed examination by transmission electron microscopy. Lastly, blood preserved in lysis buffer during collection, and with the highest parasitaemias, was subjected to parasite DNA extraction and amplification. Comparisons between a published account of apicomplexans recorded from K. b. belliana in Mozambique, and those found in the current study, identified two haemogregarine species. In the present research, Haemogregarina fitzsimonsi Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/3 (66%) captive Kwazulu-Natal K. natalensis, 7/14 (50%) captive Kwazulu- Natal K. b. belliana, 3/6 (50%) captive Kwazulu-Natal G. p. pardalis, 2/41 (5%) wild G. p. babcocki and 13/37 (35%) captive Gauteng G. pardalis. In addition, Haemogregarina parvula Dias, 1953, infected 2/14 (14%) captive K. b. belliana and 1/10 (10%) captive G. p. pardalis. An unknown species of haemogregarine, possibly also H. fitzsimonsi occurred in 6/16 (38%) Chersina angulata from the Western Cape. As well as haemogregarines, two haemoproteids were identified: Haemoproteus balazuci Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/2 (100%) captive Gauteng K. lobatsiana and 1/41 (2%) wild North West G. p. babcocki; Haemoproteus sp., a likely new species, was found in 1/3 (33%) captive K. natalensis. Infections with Haemogregarina and Haemoproteus were not concurrent in this study, but were found to occur concurrently in Dias (1953) findings, and only the two Haemogregarina spp. occurred together in captive Kwazulu-Natal G. p. pardalis tortoises, which do not occur naturally in the region. Haemogregarina fitzsimonsi did not appear region or host specific, since it infected 5/6 species of tortoises from all provinces sampled. Haemogregarina parvula apparently existed only in tortoises from Kwazulu-Natal. Furthermore, captive Gauteng female tortoises were found to have a higher rate of infection than males and heavier tortoises showed a lower intensity infection than lighter and younger tortoises. On average season appeared to have a slight affect on parasite prevalence, with a higher prevalence during the summer rather than the winter, possibly a result of the activity of the assumed vector, which may be the tick species Amblyomma marmoreum (found on G. pardalis) and/or Amblyomma hebraeum (found on C. angulata). For the new Haemoproteus sp., the small sample size meant that meaningful data on host-specificity and range was not gathered, but Hp. balazuci occurred in K. lobatsiana in the drier regions of the North West and Gauteng. Although DNA extraction was possible for H. fitzsimonsi, the technique requires further refinement and samples with greater parasitemias before it can be used with additional material, and sequencing can be attempted. Thus, new localities, hosts, host data and possible vectors (ticks) were recorded for the apicomplexan species identified by Dias (1953) and they were re-described using modern techniques. Also, possibly new Haemogregarina and Haemoproteus spp. were recorded, but their identity requires confirmation by DNA analysis. It is anticipated that these, and future results, will increase the knowledge of the ecology and biodiversity of apicomplexan haematozoans parasitising chelonian hosts in South Africa, with possible application to the conservation of these and other tortoise species around the world.

No description available.

Yes / Although several research studies have been conducted on investigating the bond stress – slip behaviour of Glass-Fibre Reinforced Polymer (GFRP) bars embedded in high strength concrete (HSC) using a pull-out method, there is no published work on the bond behaviour of GFRP bars embedded in high strength concrete using a hinged beam. This paper presents the experimental work consisted of testing 28 hinged beams prepared according to RILEM specifications. The investigation of bond performance of GFRP bars in HSC was carried out by analysing the effect of the following parameters: bar diameter (9.5, 12.7 and 15.9 mm), embedment length (5 and 10 times bar diameter), surface configuration (helical wrapping with slight sand coating (HW-SC) and sand coating (SC)) and bar location (top and bottom). Four hinged beams reinforced with 16 mm steel bar were also tested for comparison purposes. The majority of beam specimens failed by pull-out. Visual inspection of the test specimens showed that the bond failure of GFRP (HW-SC) bars usually occurred owing to the bar surface damage, while the bond failure of GFRP (SC) bars was caused due to the detachment of sand coating. The GFRP bars with helical wrapping and sand coated surface configurations showed different bond behaviour and it was found that the bond performance of the sand coated surface was better than that of the helically wrapped surface. Bond strength reduced as the embedment length and bar diameter increased. It was also observed that the bond strength for the bottom bars was higher than that of the top bars. The bond strength was compared against the prediction methods given in ACI-440.1R, CSA-S806 and CSA-S6 codes. All design guidelines underestimated the bond strength of both GFRP re-bars embedded in high strength concrete. / Ministry of Higher Education in Libya for funding.

Volvo trucks are involved in a project with vehicle combinations longer than 25.25 meters and/or with a weight of more than 64 tons. Those combinations are called high capacity transport (HCT). Some of the vehicle combinations are now driven with exemptions for the coupling equipment. The exemption is needed because according to a standard the theoretical transmitted forces between the dolly and the truck exceed the value that the coupling components have been certified for. The theoretical transmitted forces are called performance indexes. This limits the development but the exception could be avoided by using a hinged drawbar on the dolly.  This thesis aims to investigate what needs to be done in order to introduce dolly with hinged drawbar in longer and heavier vehicle combinations. A literature study and interviews were conducted to find problems that could be expected when using hinged drawbar on dolly and to investigate how the performance indexes for a specific vehicle combination should be calculated. Thereafter a dolly was put together through a product development process. Then concepts to solve a problem that was noticed through the literature study were developed. The concepts were sketched, evaluated in a matrix and thereafter the winning concept was modelled in detail in computer aided design (CAD).   According to the traffic definition in Sweden a dolly with hinged drawbar is violating the law. It defines a dolly as a module with rigid drawbar. On the other hand, the European Union defining a dolly as a trailer with fifth- wheel made to convert a semi-trailer into a full trailer. They don’t mention anything that contradicts to the usage of hinged drawbar. So the Swedish definition of a dolly needs to be challenged.   Simulations have shown that the braking performance will be worse when using a dolly with hinged drawbar compared to using a dolly with rigid drawbar. Therefore concepts to improve the braking performance of the dolly have been developed. The concept was to look the fifthwheel from pivoting around a horizontal axle perpendicular to the driving direction. By doing so the dolly and semi-trailer will become more like a full trailer and that would better the braking performance.  Through interviews and literature study it was noticed that the high performance indexes were calculated in an incorrect way. The highest forces are generated through interaction forces which are only affected by the vehicles closest to the coupling components. Therefore a calculation model need to be modified for this. Three calculation models were tested on the vehicle-combination. Two of these generated performance indexes that were reasonable. The calculation models were ISO-combination 3 and a model developed by Sweatman (1980). These two calculation models are modified for vehicle combinations that includes three vehicles. / Volvo lastvagnar ingår i ett forskningsprojekt med lastbilskombinationer som är längre än 25,25  meter och/eller väger mer än 64 ton. Ett sådant fordon kallas högkapacitetstransport (HCT). Idag körs vissa av dessa fordon med dispenser för kopplingsutrustningen. Detta då de teoretiska överförda krafterna mellan lastbil och dolly enligt en standard får värden som är högre än vad kopplingsutrustningen är certifierad med. De teoretiska överförda krafterna benämns som prestandaindex. Denna dispens skulle kunna undvikas genom att använda en ledad dragstång på dollyn.  Detta examensarbete syftar till att undersöka vad som behöver göras för att introducera dolly med ledad dragstång i längre och tyngre fordonskombinationer. En litteraturundersökning samt intervjuer genomfördes för att upptäcka problem som kan uppstå vid användande av dolly med ledad dragstång. Även en undersökning gällande hur prestandaindex ska beräknas på rätt sätt genomfördes.  Därefter konstruerades en dolly genom en produktutvecklingsprocess. Koncept för att lösa ett problem som noterades under litteraturundersökningen utvecklades. Koncepten skissades och blev sedan utvärderade genom en matris. Det vinnande konceptet konstruerades i CAD.   Från litteraturstudien visade det sig att det finns en motstridighet i den svenska definitionen gällande användandet av ledad dragstång på dolly. I Sverige definieras dolly som en kärra. En kärra definieras som en modul med stel dragstång. Däremot definierar EU dolly som en trailer som konverterar en semi-trailer till en full trailer. Där nämns ingenting som kan stoppa användandet av dolly med ledad dragstång. Därför borde den svenska definitionen utmanas.   En dolly med ledad dragstång förväntas ha sämre bromsprestanda än en vanlig dolly. Koncept utvecklades för att förbättra bromsprestandan på dollyn. Konceptet som vann var att låsa vändskivan från att vridas runt en horisontell axel vinkelrätt till åkriktningen. På så viss blir kombinationen dolly, semi-trailer mer som en full trailer vilket skulle innebära en bättre bromsprestanda.  Från intervjuer med kunniga personer och från litteraturstudien framkom det att de höga prestanda indexen var felaktigt beräknade. Det blev även känt att de största krafterna genereras genom interaktionskrafter som endast påverkas av de närmaste fordonens vikt. Tre olika beräkningsmodeller testades där två utav dem gav värden som kan anses vara rimliga. Beräkningsmodellerna var ISO-kombination 3 och en modell utvecklad av Sweatman (1980). Dessa två är anpassad för kombinationer som innehåller 3 fordon.

The content of this diplom is about design and assesment of a steel footbridge for pedestrians and cyclists across the river Ostravice. In an introduction of the work are compared two possible options of footbridge structures.and then the appropriate one is processed in detail. The chosen variant is made of two parabolic arches tilted to each other on which is suspended deck by suspenders. In a static aspect the main loadbearing beams are two-hinged arches. The bridge deck consists of two steel beams and floor beams which are composited with a reinforced concrete slab. The span length is 80 m and archs camber is 9,12m. The main material of the structural elements is steel S355.

The aim of my Diploma Thesis is to design and analyse the carrier steel construction of the three-aisled storehouse in location Frýdek-Místek. The object is constructed as spatial frame structure with solid joints which sits hinged on base footings. The hall is of rectangular ground plan sizing 30x46 metres with axial span of transverse links 9,0m + 12,0m + 9,0m and lenght of transverse links 12,0m. The carrying roof construction is made of full-length framed rungs and lattice purlins with parabolic lower belt. A main-aisle roof is saddle with the angle of 5 degrees and its top in height of +9m. The sided-aisle roofs are rack-type with the same angle. The construction sheating is made of polyurethan panel system with trapezium profile. The load consists of its own weight, other usable still and climate load in the form of wind and snow in regards of considered location. The static assessment is performed in SciaEngineer 2012 programme.

Flaps used in modern aircraft are known to produce high-intensity noise. Their blunt side edges of the wing's flap produce vorticial wakes which are the main contributors to the noise generated. A concept called continuous mold-line (CML) link flap has been studied rigorously for its impact on the acoustic behavior of the wing. These studies found that eliminating the blunt side tips with a continuous mold-line reduces the noise generated by the wing, drastically. However, very few studies have discussed the effects of mold-line shape on its aerodynamic characteristics. Therefore, the objective of this research is to investigate the effect of shape and geometry on the aerodynamics of CML wings. First, the shape of the continuous mold-line is parametrized using a hyperbolic tangent curve. Then, using ANSYS FLUENT a computational model is developed to calculate the lift and drag generated by different CML configurations. Both, inviscid and viscous studies are performed using FLUENT's pressure-based solver. The effect of span and slope at the mid-point of the transition zone are discussed. The study found that the slope at the mid-point of the transition zone does not affect the overall lift generated by the wing. Also, increasing the span of the transition zone initially increases the drag and begins to decrease at higher span lengths. Overall, it was found that the aerodynamic characteristics (such as lift, drag, and efficiency) of the CML wing are better than the conventional blunt tip hinged flap. / Master of Science / Flaps used in modern aircraft are known to produce high-intensity noise. One of the main contributors to the high-intensity noise is the blunt side edges of the wing's flap. To eliminate the noise produced by the flaps, researchers have come up with a concept called continuous mold-line (CML) link flap. In this concept, we join the flap side edge with the main wing and thus remove the side edges. Studies undertaken till now have mainly focused on the acoustic aspects of the CML wing. Hence, this study focuses on the effect the mold-line shape has on the wing's aerodynamic behavior. The study first discusses a parametric curve that will be used to define the shape of the CML region of the wing. Then, the study calculates the aerodynamic characteristics, such as lift and drag generated by the wing, using the commercial software ANSYS FLUENT. The results obtained by changing the slope at the mid-point and length of the CML region are discussed. Finally, the study presented also compares the aerodynamic characteristics (such as lift, drag, and efficiency) of the CML wing are better than the conventional blunt tip hinged flap.

The subject of the thesis was the design of a multi-storey office building. In the transverse direction the building was designed as a three-tract 6.0 + 4.0 + 6.0 = 16 m. In the longitudinal direction 9x6.6 m = 59.4 m. The design was designed in several variants: articulated and frame in transverse directions. The joint variant was selected for detailed analysis.

The thesis deals with the design and structural assessment of the swimming pool object in Dobruška. The solved structure has been chosen of the 2 preliminary variants. The dimensions of the rectangular floor plan are 34,10x40,99 m and the height of the ridge is 13,83 m. The structural system consist of two-hinged arched trusses which are connected with solid-web purlins and girts. The spatial rigidity is provided by combination of longitudinal and sway bracings. The cladding comprises of Kalzip roof system and a glass facade.