The composite material of different density, where porous cement paste serves as matrix and crushed waste expanded polystyrene packages serve as inclusions, was developed. The compositions of formative mixtures and technological parameters of production for this composite material were selected and its properties were investigated. / Sukurta skirtingo tankio kompozitinė medžiaga, kurioje matrica yra poringoji cemento tešla, o intarpai - trupintos polistireninio putplasčio pakavimo taros atliekos. Parinktos minėtos kompozitinės medžiagos formavimo mišinių sudėtys, gamybos technologiniai parametrai ir ištirtos jos bandinių savybės.

Concrete, due to its low cost, durability and fire resistance, is one of the world’s most widely used construction materials. Concrete is typically reinforced with steel bars and welded wire mesh. Since the cost of steel is increasing and steel corrosion is a significant contributor to structural failure, it is advantageous to find an alternative replacement reinforcement material which can not only replace the steel, but also resist corrosion. Over the past few decades, polymeric fibres have been used as concrete reinforcement. The chemical bond between the polymeric fibre and the cementitious matrix is an important factor in the fibre’s performance as a concrete reinforcement. Despite the great importance of the chemical bonding at the polymeric fibre/concrete interface, the chemical bonding at the interface is not well understood. To investigate the chemical interactions between polymeric materials and concrete, model systems of polymeric powder/white cement and polymeric fibre/white cement were chosen, where white cement was chosen for its suitability for nuclear magnetic resonance (NMR) experiments. The chemical interactions between poly(ethylenevinyl acetate) (EVA), poly(ether imide) (PEI), and poly(vinylidene fluoride) (PVDF) polymeric powders were studied via 13C NMR spectroscopy. It was found that EVA admixture undergoes hydrolysis in a cementitious matrix and follows a pseudo-second order kinetics model up to 32 days of cement hydration. PEI was also found to undergo hydrolysis at the imide functional group in a cementitious matrix. PVDF powder undergoes dehydrofluorination in the cementitious environment, producing a brown coloured polymer which is a result of conjugation of the polymer backbone. The interfacial transition zone between fluoropolymeric powder/white cement and steel and polymeric fibres (high density polyethylene/polypropylene, poly(vinyl alcohol), PEI, PVDF, and Nylon 6.6) was studied at short range using 19F, 27Al, and 43Ca NMR spectroscopy and at long range using the scanning electron microscopy/energy dispersive spectroscopy method. It was concluded that the chemistry of polymeric fibres themselves can alter the surrounding interfacial transition zone such that the calcium silicate hydrate favours a tobermorite or jennite-like structure, which could contribute to a strong or weak interface.

It is a common observation that organizations of violence make use of moral transgression to bond new recruits to the group’s authority figures and to encourage compliance to them. The present study drew on the work of Festinger (1957), Aronson and Mills (1959) and Martens et al. (2007) and, for the first time examined this observation empirically. It was hypothesized that when participants agreed to make a moral transgression for the experimenter that they would come to view him more positively, see him as more professional and become more compliant to him, and that this would happen even more when that choice to comply was made salient. Participants were asked to place a number of bugs into a modified coffee grinder that ostensibly exterminated the bugs and then to activate the device. No bugs were killed in any condition, but participants were either led to believe that they were killing the bugs or informed that it was just a simulation. Subsequent positivity in the perception of the experimenter and how professional they considered him to be was then measured by questionnaire and compliance to him was measured in an optional data-entry task. Results yielded partial support for the research hypotheses suggesting that at least under some circumstances, agreeing to make a personal moral transgression for an authority figure leads to increases in the positivity in the perception of that figure and compliance to him and that making that choice salient enhances this effect. The implications of this finding for the understanding of the processes by which a person can become bonded to unsavory authority-figures and potential applications to community education programs are discussed; as are the limitations of this study and possibilities for future research.

In order to be sustainable, companies have to adapt in the ever–changing market and economic conditions which are often unpredictable. The adaptation to these challenges rests with employees who have to stay motivated and psychologically well. The environmental working conditions are often undesirable The objective of this study was to evaluate the psychometric performance of the Utrecht Work Engagement Scale (UWES) and the Oldenburg Burnout inventory (OLBI) within the cement factory. A random sampling approach was adopted by distributing a questionnaire for the purposes of achieving the general research objective with an availability sample (N = 187). The UWES and OLBI were administered. Exploratory factor analysis, descriptive statistics, Cronbach alpha coefficients, Pearson product–moment correlations and MANOVA's were used to analyse the data. The outcome of the study through literature review confirmed that work engagement and burnout are two important components of employee wellbeing. The factor loadings of the UWES and OLBI resulted in a two–factor structure for both the UWES and OLBI. The two factor structure for the UWES were labelled as Vigour/Dedication and Absorption. The twofactor structure for the OLBI was labelled Disengagement and Exhaustion. A small number of items were retained for the OLBI. The internal consistency of the UWES was found to be well above the acceptable level with the alpha coefficients exceeding 0,70. The internal consistency for the OLBI was found to be lower than the 0,70 level. Data analysis further showed that correlations between engagement and burnout were statistically insignificant. Data analysis also showed that there were no vi significant differences for age and gender for both engagement and burnout, however there is a significant difference in race and language with regard to engagement but none for burnout. Limitations within the study were identified and recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2011.

In order to be sustainable, companies have to adapt in the ever–changing market and economic conditions which are often unpredictable. The adaptation to these challenges rests with employees who have to stay motivated and psychologically well. The environmental working conditions are often undesirable The objective of this study was to evaluate the psychometric performance of the Utrecht Work Engagement Scale (UWES) and the Oldenburg Burnout inventory (OLBI) within the cement factory. A random sampling approach was adopted by distributing a questionnaire for the purposes of achieving the general research objective with an availability sample (N = 187). The UWES and OLBI were administered. Exploratory factor analysis, descriptive statistics, Cronbach alpha coefficients, Pearson product–moment correlations and MANOVA's were used to analyse the data. The outcome of the study through literature review confirmed that work engagement and burnout are two important components of employee wellbeing. The factor loadings of the UWES and OLBI resulted in a two–factor structure for both the UWES and OLBI. The two factor structure for the UWES were labelled as Vigour/Dedication and Absorption. The twofactor structure for the OLBI was labelled Disengagement and Exhaustion. A small number of items were retained for the OLBI. The internal consistency of the UWES was found to be well above the acceptable level with the alpha coefficients exceeding 0,70. The internal consistency for the OLBI was found to be lower than the 0,70 level. Data analysis further showed that correlations between engagement and burnout were statistically insignificant. Data analysis also showed that there were no vi significant differences for age and gender for both engagement and burnout, however there is a significant difference in race and language with regard to engagement but none for burnout. Limitations within the study were identified and recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2011.

Concrete block pavement (CBP) can be an alternative pavement to asphalt and concrete pavements. CBP is formed from individual concrete paving blocks (CPBs) that fit next to one another on a suitable sub base leaving a specific joint space among them to be filled with jointing sand. CBP differ from other pavements according to their mechanical behavior, manufacturing technique, structural design, installation technique and structural behavior. For a serviceable pavement all of these subjects have to be studied. The literature about the mechanical behavior of CPBs is not adequate. This study aims to determine the performance of CPBs formed from different mixes prepared with a white portland cement. For this purpose, 10 mixes with different cement contents and W/C ratios and 2 mixes from a commercial CPB manufacturer were tested. The compressive strength, tensile splitting strength, abrasion resistance, density and % water absorption tests were performed on each mix at 7, 14, 28 days. It was concluded that, the cement content in the mix, optimum water volume for a given cement content, the way the manufacturing equipment is operated and their interaction was effective on the mechanical properties of CPBs. It was also observed that there was no handicap to stop the abrasion resistance test at 8*22 revolutions instead of 16*22 revolutions given in TS 2824.

Ultrasonic testing of concrete is often used for the assessment of its uniformity, strength, modulus of elasticity, durability and etc. therefore, the related parameters of testing such as the transducer frequency, the specimen geometry and etc. are well-known. On the other hand, most of the concrete properties are affected by the cement and the mechanical as well as some durability properties of cements are determined through cement mortars. Applications of ultrasound on determining the properties of cement mortars are quite limited. Therefore, the required specimen dimensions, transducer frequencies have not yet been established for cement mortars. In this study, ultrasonic pulse velocity (UPV) of mortars was determined with different transducers of different frequencies for different size ans shape of specimens. Within the scope of the experimental program, three different ultrasonic frequencies (54 kHz, 82 kHz, and 150 kHz) were utilized and the relation between ultrasonic testing frequency and specimen shape was experimentally investigated. It was concluded that the mechanical properties of mortar was adversely affected by the water-to-cement ratio. It was also observed that, when the length/wavelength ratio increases, the measured UPV with different transducer frequencies tends to converge to a single value. Finally, it was also concluded that an increase in moisture content of the mortar mixtures causes an increase in UPV and a decrease in compressive strength.

Ziel der vorliegenden Arbeit war die biologische Charakterisierung neuartiger nanostrukturierter und für die Knochenregeneration geeigneter Calciumphosphatzemente (CPC). Hierzu wurde ein aus α-Tricalciumphosphat, Calciumhydrogenphosphat, gefälltem Hydroxylapatit und Calciumcarbonat bestehender CPC verwendet, der mit den Biomolekülen Cocarboxylase, Glucuronsäure, Weinsäure, Glucose-1-phosphat, Arginin, Lysin und Asparaginsäure-Natriumsalz modifiziert wurde. Ermittelt wurde dabei der Einfluss der Modifikationen auf die Proteinadsorption und die Biokompatibilität. In Vorversuchen wurden die Zementmodifikationen hinsichtlich ihrer Bindungskapazität für humane Serumproteine und für das knochenspezifische Protein Osteocalcin (OC) sowie hinsichtlich ihrer Eignung für die Adhäsion, Proliferation und osteogene Differenzierung von humanen fötalen Osteoblasten (hFOB 1.19) und humanen mesenchymalen Stammzellen (hMSC) untersucht. Dabei erwiesen sich die Modifikationen mit Cocarboxylase, Arginin und Asparaginsäure-Natriumsalz als besonders günstig. Mit diesen „Favoriten“ erfolgte eine detailliertere Analyse der Adsorption humaner und boviner Serumproteine sowie der knochen-spezifischen Proteine Osteocalcin, BMP-2 und VEGF. Dabei führte sowohl der Zusatz von Cocarboxylase, als auch der von Arginin und Asparaginsäure-Natriumsalz zu einer erhöhten Adsorption von Serumproteinen. Die Bindungsaffinität des Basiszements gegenüber Osteocalcin, BMP-2 und VEGF konnte durch Funktionalisierung mit Arginin gesteigert werden. Während die Modifizierung mit Cocarboxylase nur die VEGF-Adsorption förderte, bewirkte der Zusatz von Asparaginsäure-Natriumsalz eine Erhöhung der Osteocalcin- und BMP-2-Adsorption. Bedingt durch die größere spezifische Oberfläche der noch nicht abgebundenen Zemente, war die Menge adsorbierter Proteine auf frisch hergestellten Zementproben im Vergleich zu abgebundenen und ausgehärteten Zementen signifikant höher. Die Eignung der ausgewählten Zementvarianten als Knochenersatzmaterialien wurde mithilfe humaner mesenchymaler Stammzellen zweier verschiedener Spender getestet. Bei Verwendung abgebundener und ausgehärteter Zemente waren die hMSC in der Lage, auf allen Modifikationen zu adhärieren, zu proliferieren und in die osteogene Richtung zu differenzieren. Eine vorherige Inkubation der Zementproben mit humanem Serum förderte dabei vor allem die Zelladhäsion. Weiterhin konnte gezeigt werden, dass hMSC im Gegensatz zu anderen Studien auch auf frisch hergestellten Zementproben adhärieren, proliferieren und differenzieren können. Die Modifizierung des Basiszements mit Cocarboxylase führte hierbei zu einer gegenüber den anderen Modifikationen signifikant erhöhten Zelladhäsion und -vitalität. Neben den verschieden modifizierten Pulver/Flüssigkeitszementen wurden im Rahmen dieser Arbeit neuartige ready-to-use Zementpasten untersucht. Diese zeigten allerdings im Vergleich zu den herkömmlichen Zementen eine geringere Proteinbindungsaffinität. HMSC, die auf den Pastenzementen kultiviert wurden, war es wiederum möglich zu adhärieren, zu proliferieren und den osteoblastenspezifischen Marker Alkalische Phosphatase zu exprimieren. Hinsichtlich ihrer Biokompatibilität sind sie damit vergleichbar zu den herkömmlichen Pulver/Flüssigkeitszementen.

The most common cause for revision total hip replacement surgey is aseptic loosening of the acetabular component. This thesis explores the effect of three techniques to improve the depth and quality of cemented acetabular component fixation in primary total hip replacement. This may have beneficial effects on the longevity of cemented acetabular components and reduce the rate of revision surgery for aseptic loosening. Aims: 1. Determine the effect of the rim cutter on cement pressure during cup insertion. 2. Examine the effect of the rim cutter on cement penetration distance. 3. Evaluate the effect of bone grafting of the acetabular notch. 4. Determine the effect of iliac suction during cement pressurisation. 5. Compare the behaviour of bone cement with Play Dough. Materials and Methods: 1. Sawbones hemi pelvis models were fitted with pressure transducers at the rim and apex of the acetabulum. Peak pressure was measured upon insertion of cups with different flange sizes and when the acetabulum was prepared with the rim cutter. 2. Foam cavities were used to measure the depth of cement penetration when the same cups and rim cutter were used. 3. Hemi pelvis models were modified to simulate bone grafting of the acetabular notch. Again, pressure sensors were mounted at the apex and rim of the acetabulum. Intra-acetabular cement pressure was compared with native acetabulae. 4. A back bleeding model of the acetabulum was fitted with a suction catheter. The effect on cement penetration into cancellous bone was measured compared with no suction. 5. Play Dough pressurisation and penetration into hemi pelvises and foam was compared to bone cement. Results: 1. Significant increase in peak apex and rim pressures when flanged cup inserted into an acetabulum prepared with the rim cutter compared with both flanged and unflanged cups alone. 2. Significant increase in cement penetration at the rim of the acetabulum when rim cutter used and flanged cup inserted when compared with flanged and unflanged cups alone. 3. Significant increase in intra-acetabular pressure when cement pressurised in presence of simulated acetabular notch bone grafting compared with normal acetabulae. 4. Significant increase in cement penetration distance when suction used compared with no suction. 5. Significant differences in the flow characteristics between bone cement and Play Dough. Conclusion: The authors recommend preparation of the acetabular rim with the rim cutter and bone grafting of the acetabular notch to improve the depth and uniformity of the cement mantle in cemented primary THA. Play Dough at room temperature is not a suitable substitute for bone cement in in-vitro cementing studies.

Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders. / Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams. / For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams. / For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.