The calculation of acceleration costs on construction projects

A lack of understanding often exists between contractors, client organisations and consultants as to what may, and what may not, be included in acceleration claims on construction projects. The aim of this article is to create a better understanding of the complexity of acceleration claims. It should also lead to new insights into claim procedures and the substantiation of acceleration costs. The impacts and delays which may result in acceleration claims on a project were analysed as they form the basis for establishing liability in terms of a particular contract. Matters of principle that are applicable to acceleration claims, regardless of the form of contract recommended for use in the South African construction industry, were also examined. The findings indicate that there are significant differences on a number of aspects regarding the calculation of acceleration costs on construction projects between contractors, consultants and employers/developers. The majority of the respondents, however, were of the opinion that of the various methods used for calculating acceleration costs, the time impact analysis is most frequently applied, but that the modified total cost approach is the method most suitable on projects where there is a significant increase in the scope of work, something that occurs regularly on construction projects

The influence of the horn effect in tyre/road noise

The horn effect is known as an important amplification mechanism in tyre/road noise. The name is referring to the geometry between tyre and road surface which resembles an exponential horn. The horn effect is a common subject for both experimental and numerical research. Contrary to previous studies which considered point sources, this paper focusses on the horn effect by simulated tyre vibrations. The amplification of acoustic pressure, however, depends largely on the location of the observer. The sound power can be used as a measure for the horn effect which is independent on the point of observation. In this paper, the sound radiation problem is solved using the boundary element method (BEM). First, a case study considering equivalent point sources is used to validate the accuracy of the boundary element model and solver using experimental results. Next, the vibrations of tyres rolling on textured road surfaces are investigated numerically. The computed tyre vibrations are used to study the horn effect using different tyre designs. The amplification by horn effect is determined by the combined tyre/road geometry and the distribution of the noise. The current method may be used to systematically study the influence of the horn effect, for example, during tyre development

Multiwavelength Monitoring of the BL Lacertae Object PKS 2155-304 in May 1994. I. The Ground-Based Campaign

Optical, near-infrared, and radio observations of the BL Lac object PKS2155-304 were obtained simultaneously with a continuous UV/EUV/X-ray monitoring campaign in 1994 May. Further optical observations were gathered throughout most of 1994. The radio, millimeter, and near-infrared data show no strong correlations with the higher energies. The optical light curves exhibit flickering of 0.2-0.3 mag on timescales of 1-2 days, superimposed on longer timescale variations. Rapid variations of ~0.01 mag/min, which, if real, are the fastest seen to date for any BL Lac object. Small (0.2-0.3 mag) increases in the V and R bands occur simultaneously with a flare seen at higher energies. All optical wavebands (UBVRI) track each other well over the period of observation with no detectable delay. For most of the period the average colors remain relatively constant, although there is a tendency for the colors (in particular B-V) to vary more when the source fades. In polarized light, PKS 2155-304 showed strong color dependence and the highest optical polarization (U = 14.3%) ever observed for this source. The polarization variations trace the flares seen in the ultraviolet flux.Comment: 45 pages, latex file with encapsulated postscript, accepted to the Astrophysical Journa

Volharding in teosentriese perspektief volgens die boek Openbaring

D. Litt. et Phil. (Theology)Please refer to full text to view abstrac

The calculation of acceleration costs on construction projects

A lack of understanding often exists between contractors, client organisations and consultants as to what may, and what may not, be included in acceleration claims on construction projects. The aim of this article is to create a better understanding of the complexity of acceleration claims. It should also lead to new insights into claim procedures and the substantiation of acceleration costs. The impacts and delays which may result in acceleration claims on a project were analysed as they form the basis for establishing liability in terms of a particular contract. Matters of principle that are applicable to acceleration claims, regardless of the form of contract recommended for use in the South African construction industry, were also examined. The findings indicate that there are significant differences on a number of aspects regarding the calculation of acceleration costs on construction projects between contractors, consultants and employers/developers. The majority of the respondents, however, were of the opinion that of the various methods used for calculating acceleration costs, the time impact analysis is most frequently applied, but that the modified total cost approach is the method most suitable on projects where there is a significant increase in the scope of work, something that occurs regularly on construction projects.Daar is dikwels onsekerheid by aannemers, kliënte-organisasies en konsultante oor wat mag, en wat mag nie, in versnellingseise op konstruksieprojekte ingesluit word. Die doel van hierdie artikel is om ’n beter begrip rakende die kompleksiteit van versnellingseise te bewerkstellig. Die artikel behoort ook te lei tot nuwe insigte oor die prosedures vir eise en die substansiëring van versnellingskoste. Die oorsake en vertragings wat aanleiding gee tot versnelling op ’n projek is ontleed aangesien dit die grondslag vir die bepaling van aanspreeklikheid ingevolge ’n spesifieke kontrak vorm. Belangrike prinsipiële aspekte wat op versnellingseise betrekking het, ongeag die kontrakvorm wat in die Suid-Afrikaanse konstruksiebedryf vir gebruik aanbeveel word, is verder ondersoek. Die bevindinge dui daarop dat daar tussen aannemers, konsultante en kliënte/ ontwikkelaars aansienlike verskille op verskeie aspekte bestaan met betrekking tot die berekening van versnellingskoste op instruksieprojekte. Meeste respondente was egter van mening dat die “time impact analysis”-benadering die meeste toegepas word, maar dat die “modified total cost”-benadering die mees geskikte metode is op projekte waar daar ’n beduidende toename in die omvang van werk is, iets wat dikwels op konstruksieprojekte voorkom.Articl

On solving the tyre-road contact problem at high frequencies. (cd-rom)

The contact between tyre and road is non-linear and most accurately described in the time domain. Currently however, accurate finite element models are too large to be solved at the small time scales required to capture tyre/road noise. At the Structural Dynamics and Acoustics group of the University of Twente an alternative contact algorithm has been developed. The algorithm solves the dynamic equations and, while solving, satisfies exactly the contact condition (the condition that states that there is no penetration of the tyre into the road). As a result, there is no need for contact elements and no additional parameters are required to stabilize the solution process. The possibility to optimize and speed up the algorithm by means of multigrid is the major advantage of the new approach. In this paper the contact algorithm is explained for a finite element discretization

A strategic framework to utilise venture capital funding to develop manufacturing SMEs in South Africa

CITATION: Snyman, H. A., Kennon, D., Schutte, C. S. L. & Von Leipzig, K. 2014. A strategic framework to utilise venture capital funding to develop manufacturing SMEs in South Africa. South African Journal of Industrial Engineering, 25(2):161-181, doi:10.7166/25-2-816.The original publication is available at http://sajie.journals.ac.zaSMEs contribute considerably to the national GDP and to private sector employment, but they struggle to gain access to the funding needed to support business sustainability and growth. Venture capital provides the necessary funding, but SMEs lack understanding of the business value curve utilised by financiers to gauge the risk-reward characteristics of an investment. Strategies need to convey how the business model will evolve in order to deliver on the strategic intent. A framework is proposed through which SMEs can develop a strategy aligned with investor requirements. As a case study, the framework is applied to the local tooling sector.SMEs dra betekenisvol by tot die nasionale BBP en werkskepping in die private sektor, maar SMEs sukkel om toegang te kry tot befondsing wat nodig is vir groei en volhoubaarheid. Waagkapitaal kan die nodige befondsing verskaf, maar SMEs benodig kennis van die besigheidswaarde kurwe, wat deur beleggers gebruik word om die risiko-opbrengs van ’n belegging te assesseer. Strategieë moet oordra hoe die besigheidsmodel die strategiese intensie gaan aflewer. ’n Raamwerk word voorgestel waardeur die SME ’n strategie kan ontwikkel wat belyn is met die vereistes van beleggers. As gevallestudie word die raamwerk toegepas op die plaaslike gereedskap sektor.http://sajie.journals.ac.za/pub/article/view/816Publisher's versio