An investigation to introduce BIM in undergraduate civil engineering teaching to improve construction processes

Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The popularity of Building Information Modelling (BIM) has grown rapidly within the construction industry, motivated by its potential advantages for improving construction processes. A majority of the world’s leading firms have adopted BIM solutions by moving from 2D or even 3D CAD to BIM techniques. However, for companies in South Africa this transition has not been the same as for firms in Europe and the USA. Besides the improvements which can be achieved by viewing a computer model of the designed facility, BIM provides a multi-disciplinary tool, to be used for collaboration of all project parties in a real-time simulated model of construction process. Due to this remarkable feature, the way of constructing a designed facility can be viewed and analysed from the conceptual stages and can improve design and construction processes. As this object-oriented approach has been developed in the industry, handbooks and standards have been released to support BIM utilization. A considerable amount of research has been conducted to establish the advantages and barriers in applying BIM. A large number of investigations have also been performed for reporting quantified achievement of construction projects executed in BIM environment. As such, a new knowledge field has been added to the industry requirements. BIM knowledge has become more demanding and BIM-specialist requirements have been enhanced. As a result, academia have been stimulated to raise BIM awareness among engineers, architects and construction managers to train sufficiently qualified professionals for applying BIM tools. Universities started offering different courses and programmes to fulfil this need while a variety of strategies have been developed for introducing BIM to the students at different levels. This research studied the current industry situation in South Africa regarding application of BIM and the role of universities to achieve a suitable level of BIM capability. The industrial and educational situations from some pioneering countries are reviewed as lessons for the South African adoption of BIM. Comparing these facts, proposals for introducing BIM through university courses are provided to satisfy industry requirements for the application of BIM in projects.AFRIKAANSE OPSOMMING: Die gewildheid van Bou Inligtingsmodelle (Building Information Modelling (BIM)) het vinnig gegroei in die konstruksie bedryf as gevolg van die voordele wat dit vir die verbetering van konstruksieprosesse inhou. ʼn Groot aantal van die wêreld se voorste konstruksie maatskappye het al die oorgang vanaf 2D en selfs 3D RGT (Rekenaar Gesteunde Tekenstelsels) na BIM gemaak. Ongelukkig is hierdie oorgang na BIM metodes nog nie so doeltreffend vir maatskappye in Suid- Afrika soos in die geval van Europese en Amerikaanse maatskappye nie. Daar is al bewys dat die vermoë om na ʼn rekenaarmodel van ʼn ontwerpte fasiliteit te kan kyk baie voordelig is. Daarbenewens bied BIM ʼn multidissiplinêre grondslag wat vir die samewerking van alle betrokke partye van die projek gebruik kan word en die projek kan simuleer as ʼn funksie van tyd. Hierdie tyd-afhanklike simulasie stel die bestuur in staat om die manier waarop ʼn ontwerpte fasiliteit gebou word, reeds vanaf die konsepsuele fase, te beskou en te ontleed. Hierdie vermoë kan die ontwerp en konstruksieproses asook die fasiliteitsbestuur proses merkwaardig verbeter. As gevolg van die ontwikkeling van hierdie objek georiënteerde benadering deur die bedryf, is handboeke en standaarde vrygestel om die gebruik van BIM te ondersteun. ‘n Merkwaardige hoeveelheid navorsing is al gedoen om die voordele en struikelblokke in die toepassing van BIM te identifiseer. ‘n Groot aantal ondersoeke is ook al geloots om verslag te doen op die prestasie van konstruksie projekte wat deur middel van BIM uitgevoer was. Vanuit die bogenoemde ondersoeke en navorsing is 'n nuwe kennisveld gevoeg by die vereistes van die bedryf. Die kennis van BIM het al hoe meer veeleisend geword en die vereistes vir ʼn BIMspesialis het verhoog. As gevolg hiervan is akademici aangemoedig om ingenieurs, argitekte en konstruksie bestuurders meer bewus te maak van BIM sodat daar genoeg professionele werkers opgelei kan word wat BIM kan implementeer. Universiteite het begin om kursusse en programme aan te bied om hierdie behoefte te bevredig, terwyl 'n verskeidenheid metodes om studente bloot te stel aan BIM op verskillende vlakke ontwikkel is. In hierdie navorsingsprojek is die huidige stand van Suid-Afrikaanse konstruksiemaatskappye ten opsigte van die toepassing van BIM ondersoek. Daarbenewens is die rol wat universiteite speel om 'n voldoende vlak van BIM vaardigheid te bereik ook ondersoek. Die industriële en opvoedkundige omgewings van 'n paar vooraanstaande lande word gebruik as lesse vir die Suid-Afrikaanse aanvaarding van BIM. Deur hierdie feite te vergelyk, is voorstelle gemaak vir die bekendstelling van BIM in universiteitskursusse om aan industrievereistes te voldoen vir die toepassing van BIM op projekte

Internal and Marginal Fit Accuracy of Pre-sintered CAD/CAM Implant-Supported Frameworks Before and After Porcelain Layering

Purpose: Internal and marginal fit accuracy of an implant-supported fixed partial denture (I-FPD) along with passive fit are required for long-term clinical success. This study compared the fit accuracy of three-unit CAD/CAM-fabricated cement retained I-FPDs milled from pre-sintered cobalt-chromium (Co-Cr) and zirconia (Zr) and evaluated the effect of applying porcelain. Materials and Methods: Two implant analogs were positioned parallel at first premolar and first molar sites in an acrylic model. Their corresponding abutments were tightened with 25-Ncm torque force. Four groups were designed: two groups of I-FPD frameworks with pre-sintered Zr (ZrF) and soft millable Co-Cr alloy (SF) blocks, and two groups by applying porcelain to the Co-Cr (SP) and Zr (ZrP) frameworks (n =4 in each group). Absolute marginal gap (AMG), marginal gap (MG), and internal discrepancies were measured. Kolmogorov-Smirnov, Levene, one-way analysis of variance (ANOVA), and Scheffe tests were used for statistical analysis using SPSS software version 22 at a significance level of .05. Results: All measured criteria were significantly different from each other (all P values <.001). The rankings from the lowest gap to the highest gap for the main criteria were as follows: MG: SF < SP < ZrF < ZrP; AMG and internal discrepancies: SF < SP < ZrP < ZrF. Comparing molars and premolars, molars had smaller MGs, larger internal discrepancies, and smaller AMG in ZrP but larger AMG in SP. Conclusion: All three-unit CAD/CAM-fabricated cement-retained I-FPDs were in the clinically acceptable range of fit accuracy. The lowest and highest misfit values were observed in the SF and ZrF groups, respectively

The impact of frying aerosol on human brain activity

Knowledge on the impact of the exposure to indoor ultrafine particles (UFPs) on the human brain is restricted. Twelve non-atopic, non-smoking, and healthy adults (10 female and 7 male, in average 22 years old) were monitored for brain physiological responses via electroencephalographs (EEGs) during cooking. Frying ground beef meat in sunflower oil using electric stove without ventilation was conducted. UFPs, particulate matter (PM) (PM1, PM2.5, PM4, PM10), CO2, indoor temperature, RH, oil and meat temperatures were monitored continuously throughout the experiments. The UFP peak concentration was recorded to be approximately 2.0 × 105 particles/cm3. EEGs were recorded before exposure, at end of cooking when PM peak concentrations were observed, and 30 min after the end of the cooking session (post-exposure). Brain electrical activity statistically significantly changed during post-exposure compared to the before exposure, suggesting the translocation of UFPs to the brain, occurring solely in the frontal and temporal lobes of the brain. Study participants older than 25 were more susceptible to UFPs compared to those younger than 25. Also, the brain abnormality was mainly driven by male rather than female study participants. The brain slow-wave band (delta) decreased while the fast-wave band (Beta3) increased similar to the pattern found in the literature for the exposure to smoking fumes and diesel exhaust

Human exposure to aerosol from indoor gas stove cooking and the resulting nervous system responses

Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm3) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 105 particle/cm3, and the average level was 1.64 × 105 particle/cm3. The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 1012 (SD = 1.83 × 1012, R2 = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R2 = 0.90, p < 0.0001) min−1, respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD

Human exposure to aerosol from indoor gas stove cooking and the resulting nervous system responses

Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm3) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 105 particle/cm3, and the average level was 1.64 × 105 particle/cm3. The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 1012 (SD = 1.83 × 1012, R2 = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R2 = 0.90, p < 0.0001) min−1, respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD

The impact of frying aerosol on human brain activity.

Knowledge on the impact of the exposure to indoor ultrafine particles (UFPs) on the human brain is restricted. Twelve non-atopic, non-smoking, and healthy adults (10 female and 7 male, in average 22 years old) were monitored for brain physiological responses via electroencephalographs (EEGs) during cooking. Frying ground beef meat in sunflower oil using electric stove without ventilation was conducted. UFPs, particulate matter (PM) (PM1, PM2.5, PM4, PM10), CO2, indoor temperature, RH, oil and meat temperatures were monitored continuously throughout the experiments. The UFP peak concentration was recorded to be approximately 2.0 × 105 particles/cm3. EEGs were recorded before exposure, at end of cooking when PM peak concentrations were observed, and 30 min after the end of the cooking session (post-exposure). Brain electrical activity statistically significantly changed during post-exposure compared to the before exposure, suggesting the translocation of UFPs to the brain, occurring solely in the frontal and temporal lobes of the brain. Study participants older than 25 were more susceptible to UFPs compared to those younger than 25. Also, the brain abnormality was mainly driven by male rather than female study participants. The brain slow-wave band (delta) decreased while the fast-wave band (Beta3) increased similar to the pattern found in the literature for the exposure to smoking fumes and diesel exhaust

Human exposure to aerosol from indoor gas stove cooking and the resulting nervous system responses.

Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm3 ) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 105 particle/cm3, and the average level was 1.64 × 105 particle/cm3 . The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 1012 (SD = 1.83 × 1012 , R2  = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R2  = 0.90, p < 0.0001) min-1 , respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD