A Method for Optimization of Materials in Construction Projects

-- C K Georgekutty and George Mathew

Material management is an important aspect in project planning and control. It contributes a major portion of expense in construction projects. Controlling procurement and carrying cost can reduce total project cost and complete the project in a fast track method. A questionnaire survey was conducted among 72 ongoing housing projects in and around Kochi. Based on the study, only 15% of the housing projects were expected to complete in time. A field solution was suggested through this study by dynamic control on inventory. Though all materials are equally important in construction, some of the key materials are specifically controlling the project cost. A B C Analysis is an apt tool for identifying those materials. If these key materials are dynamically controlled in procurement, and stored to the optimum level, project cost can be reduced. Again by resource leveling and smoothing, the usage can be brought to the optimum refined level so that much storage cost can be eliminated. The Economic Order Quantity (EOQ) of each material was arrived at this stage, and this EOQ model may further refine with sensitivity analysis. By sensitivity check, the sensitiveness of the material was found out, using ‘what-if analysis’. In this analysis, the effect of the total project was checked and the optimum solution was found. The process has to be followed till the completion of the project to optimize the total project cost.

© 2011 IUP. All Rights Reserved.

Metal Roofing on Residential Buildings: A Dynamic Thermal Simulation Study

--Ray Ogden, Christopher Kendrick, Graeme Peacock and Nicholas Walliman

The paper compares the effect of metal or tiled roofing finishes on the thermal performance of roofs of residential buildings in different climatic conditions in Europe and their contribution to the heat island effect in cities. A typical masonry house with U-values according to national requirements for four different locations in Europe was modeled using IES TAS simulation software. Metal roofs, particularly with reflective coatings, reduce cooling loads or decrease hours overheating more than tiled roofs. Metal roofs reduce heat stored in the building fabric—a major contributor to urban heat islands. With solar reflective coatings, they also reduce summertime surface temperatures during the day.

© 2011 IUP. All Rights Reserved.

Spatiotemporal Variations in the Physicochemical and Microbiological Concentrations of Groundwater in Port Harcourt, Nigeria

-- H O Nwankwoala, F A Ushie and J I Nwosu

The study involves the analyses of the physicochemical and microbiological concentrations of groundwater from 12 water samples for both dry and wet seasons. The aim was to determine the spatial and temporal variations of the ambient groundwater quality for both seasons and of the processes leading to an improved understanding of the groundwater in the area. Sixteen quality parameters include: pH, Turbidity, TSS, Conductivity, Total Hardness, Cl–, PO4, NO3–, SO42–, HCO3-, Fe, Zn, Cr, Cu and Pb. The study revealed that pH values ranged from 5.17 to 6.50 in both seasons, indicating that almost all samples were slightly acidic in both seasons. The relatively high values of some of the parameters in the wet season could be attributed to the influx of sediments from interland and waste from dumpsites as well as human activities. Heavy metal concentrations in most of the locations were found to fall below the WHO (2006) limits, except iron that exceeded the limit. The bacteriological analysis revealed that all locations were above the safe limits suggesting possible contamination by coliform bacteria from human and animal wastes.

© 2011 IUP. All Rights Reserved.

Performance Analysis of Sole Pasting Unit in a Shoemaking Plant Under Preemptive Priority Repair

-- Vikas Modgil, S K Sharma and Jagtar Singh

The paper describes the availability analysis of sole pasting system in a shoemaking unit. The components/subsystem of the system discussed in the mathematical model presented in this paper failed either directly from full capacity working state or indirectly through partial working state. These subsystems were subjected to both corrective as well as preventive maintenance. The failure and repair rates of these components/subsystems were independent and constant. The problem was formulated using probability consideration and Markov modeling. The system of equation governing the working of system was solved using normalizing condition and recursive method. The study helps in finding the crucial factors and analyzing their effect on the availability.

© 2011 IUP. All Rights Reserved.

An Analysis of 64 Northern Spiral Galaxies in Framework of Power-Law Hypothesis

-- M Thakre, N Thakre and G K Upadhyaya

One of the largest rotation curve (RC) databases of spiral galaxies currently available is provided by the kinematic and photometric data of Stephane Courteau. These RCs were originally obtained for cosmic flow studies. The final collection of RCs consists of 304 galaxies. This collection includes 64 RCs of morphological type Sb galaxies which are the subject of the present analysis. In the context of our study of these 64 northern spirals, we show that the velocity of the test particle in galactic region can be described by generalized power law. It is found that RCs impose an extremely strong correlation between the free parameters of the power law, and this correlation accounts for virtually all the variation in the pivotal diagram. The analysis brings out clearly that RCs can be partitioned into well-defined discrete subclasses. Our analysis of data yields results similar to those obtained by D F Roscoe for southern sky galaxies. This clearly indicates that galaxies can be classified into discrete subclasses according to their dynamics in context of power law.

© 2011 IUP. All Rights Reserved.