Residual value is defined as the price for which a used piece of equipment can be sold in the market at a particular time. It is an important element of the owning costs of equipment and needs to be estimated by equipment managers for making investment decisions. The purpose of this study is to gain insights into the residual value of selected groups of heavy construction equipment and to develop a mathematical model for its prediction. Auction sales data were collected from two online databases. Manufacturer publications and an online source provided size parameters and manufacturers suggested retail prices matching the auction records. Macroeconomic indicator values were collected from a variety of sources, including government agencies. The data were brought into the same electronic format and were matched by model name and calendar date, respectively. Data from auctions in the U.S. and in Canada were considered for this study. Equipment from four principal manufacturers of up to 15 years of age at the time of sale was included. A total of 35,542 entries were grouped into 11 different equipment types and 28 categories by size as measured by horse power, standard operating weight, or bucket volume. Equipment types considered were track and wheel excavators, wheel and track loaders, backhoe loaders, integrated toolcarriers, rigid frame and articulated trucks, track dozers, motor graders, and wheel tractor scrapers. Multiple linear regression analyses of the 28 datasets were carried out after outliers had been deleted. Explanatory variables for the regression model were age in years, the indicator variables manufacturer, condition rating, and geographic region, and selected macroeconomic indicators. The response variable was residual value percent, defined as auction price divided by manufacturers suggested retail price. Different first, second, and third-order polynomial models and exponential and logarithmic models of age were examined. A second-order polynomial was selected from these functional forms based on the adjusted coefficient of determination. Coefficients for the 28 models and related statistics were tabulated. A spreadsheet tool incorporating the final regression model and its coefficients was developed. It allows performing the residual value prediction in an interactive and intuitive manner. / Ph. D.

This project focuses on two important topics which may pose hazards to human health. Firstly, drinking water disinfection by-products (DBPs), which are generated by the chemical disinfection of water have been investigated. What has not been shown is the effect of DBPs in human germ cells as well as somatic cells and whether oxidative stress is involved in the mechanism of genotoxic action. Three different DBPs (halo acetic acids: HAAs), together with the antioxidants – catalase and butylated hydroxyanisole (BHA), were investigated in peripheral blood cells and sperm from healthy individuals using the Comet assay and lymphocytes only using the micronucleus assay. Secondly, nanoparticles of the non-steroidal anti-inflammatory drugs (NSAIDs), aspirin and ibuprofen, have been investigated in patients with respiratory diseases, in the micronucleus assay and the Comet repair assay. NSAIDs inhibit cyclooxygenase enzyme activity, which plays part in tumour progression. In the Comet assay, BHA and catalase were able to reduce DNA damage in both cell types compared to HAAs alone. Similarly, in the micronucleus assay, micronuclei were reduced with the antioxidants, suggesting oxygen radical involvement in both assays. With the NSAIDs, reductions were seen for DNA damage in the micronucleus assay with aspirin and ibuprofen nanoparticles compared to their bulk forms. Using the Comet repair assay, aspirin and ibuprofen nanoparticles aided repair of DNA to a greater extent than their bulk counterparts, which in turn showed better repair compared to samples repaired without NSAIDs. These observations show the importance of DBPs and NSAIDs in genotoxic public health issues.

This project focuses on two important topics which may pose hazards to human health. Firstly, drinking water disinfection by-products (DBPs), which are generated by the chemical disinfection of water have been investigated. What has not been shown is the effect of DBPs in human germ cells as well as somatic cells and whether oxidative stress is involved in the mechanism of genotoxic action. Three different DBPs (halo acetic acids: HAAs), together with the antioxidants – catalase and butylated hydroxyanisole (BHA), were investigated in peripheral blood cells and sperm from healthy individuals using the Comet assay and lymphocytes only using the micronucleus assay. Secondly, nanoparticles of the non-steroidal anti-inflammatory drugs (NSAIDs), aspirin and ibuprofen, have been investigated in patients with respiratory diseases, in the micronucleus assay and the Comet repair assay. NSAIDs inhibit cyclooxygenase enzyme activity, which plays part in tumour progression. In the Comet assay, BHA and catalase were able to reduce DNA damage in both cell types compared to HAAs alone. Similarly, in the micronucleus assay, micronuclei were reduced with the antioxidants, suggesting oxygen radical involvement in both assays. With the NSAIDs, reductions were seen for DNA damage in the micronucleus assay with aspirin and ibuprofen nanoparticles compared to their bulk forms. Using the Comet repair assay, aspirin and ibuprofen nanoparticles aided repair of DNA to a greater extent than their bulk counterparts, which in turn showed better repair compared to samples repaired without NSAIDs. These observations show the importance of DBPs and NSAIDs in genotoxic public health issues. / United Kingdom India Education and Research Initiative (UKIERI).

No / Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. OBJECTIVES: To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses.

This work was focused on study of a behaviour of the food additivum butylated hydroxyanisole on modified carbon electrodes by the voltammetric techniques - cyclic and differential pulse voltammetry. Glassy carbon and carbon paste electrode were used. Multiwalled carbon nanotubes (MWCNT) in combination with three different binders (acetonitrile, nafione or chitosane) were employed for the electrode modification. Carbon paste electrode was unable to modificate with film containing carbon nanotubes and acetonitrile, its active surface was treated only with nafione and chitosane film. All three mentioned modifications were applied in case of glassy carbon electrode. Butylated hydroxyanisole provided a significantly higher signal using electrodes modified with carbon nanotubes with all three binders in contrast to electrodes without any surface modification. The glassy carbon electrode with carbon nanotube / acetonitrile film on its surface appeared to be the most effective for analytical purposes. Voltammetric determination of butylated hydroxyanisole using this electrode provided a better defined and higher analytical signal and lower relative standard deviations in comparison with other ways of modification. The limit of detection of butylated hydroxyanisole obtained by cyclic voltammetry on glassy...