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.

An experiment was conducted to determine the effect of addition of antioxidants or encapsulation of linseed oil on the oxidative stability of linseed oil and the effect on growth and fatty acid composition of rainbow trout fed these products. Four diets differing only in their lipid sources were prepared by cold extrusion: 1) fish oil (FO), 2) linseed oil (LO), 3) linseed oil (980 g/kg) stabilized with vitamin E (7.5 g/kg) and butylated hydroxytoluene (BHT) (12.5 g/kg) (stabilized linseed oil; SLO) and 4) linseed oil (350 g/kg) containing vitamin E (7.5 g/kg), BHT (12.5 g/kg) and encapsulated in a coating material primarily consisting of hydrogenated palm oil (630 g/kg) (encapsulated linseed oil; ELO). Diets were fed twice daily to rainbow trout to apparent satiation (n=22 / replicate; 7 replicates per treatment) during a 168 day growth trial. Following the growth trial, the fish were humanely euthanized by a sharp blow to the cranium and analyzed for fatty acid composition, thiobarbituraric reactive substances (TBARS), fillet colour and sensory attributes (trained and consumer panels). There were no significant differences between treatments on any of the growth parameters investigated or TBARS levels of fish fillets. Omega-3 polyunsaturated fatty acids of trout fed LO were significantly higher than those fed FO (35.5% of total fatty acids vs. 27.6%) and ELO (28.9%) (P < 0.05). EPA and DHA levels were not significantly different between treatments. Diet samples were stored for 168 days at room temperature in sealed plastic containers. Following storage, the oxidative stability index (OSI) of the FO and LO diets were reduced to 0.00 hours while that of the SLO diet 9.20 hours and the ELO diet was 11.40 hours. Trained panelists determined fish fed FO had a significantly higher aroma intensity and significantly lower aroma desirability and overall acceptability than those fed SLO. The rancid aroma and flavour of the FO-fed fish was significantly higher than fish fed the other treatments (P < 0.05). Consumer panelists found no significant differences between the sensory attributes of fish fed the four experimental diets and exhibited no preference between treatments (P > 0.05). Fillets from fish fed FO had significantly higher values than the other three treatments for redness (3.59 vs values between 1.86 and 2.07) and yellowness (25.35 vs values between 20.51 and 21.22) (P < 0.05). Addition of antioxidants to linseed oil improves its oxidative stability during storage and processing and results in fish fillets with fatty acid composition and consumer acceptance equal or superior to fish fed fish oil.

An experiment was conducted to determine the effect of addition of antioxidants or encapsulation of linseed oil on the oxidative stability of linseed oil and the effect on growth and fatty acid composition of rainbow trout fed these products. Four diets differing only in their lipid sources were prepared by cold extrusion: 1) fish oil (FO), 2) linseed oil (LO), 3) linseed oil (980 g/kg) stabilized with vitamin E (7.5 g/kg) and butylated hydroxytoluene (BHT) (12.5 g/kg) (stabilized linseed oil; SLO) and 4) linseed oil (350 g/kg) containing vitamin E (7.5 g/kg), BHT (12.5 g/kg) and encapsulated in a coating material primarily consisting of hydrogenated palm oil (630 g/kg) (encapsulated linseed oil; ELO). Diets were fed twice daily to rainbow trout to apparent satiation (n=22 / replicate; 7 replicates per treatment) during a 168 day growth trial. Following the growth trial, the fish were humanely euthanized by a sharp blow to the cranium and analyzed for fatty acid composition, thiobarbituraric reactive substances (TBARS), fillet colour and sensory attributes (trained and consumer panels). There were no significant differences between treatments on any of the growth parameters investigated or TBARS levels of fish fillets. Omega-3 polyunsaturated fatty acids of trout fed LO were significantly higher than those fed FO (35.5% of total fatty acids vs. 27.6%) and ELO (28.9%) (P < 0.05). EPA and DHA levels were not significantly different between treatments. Diet samples were stored for 168 days at room temperature in sealed plastic containers. Following storage, the oxidative stability index (OSI) of the FO and LO diets were reduced to 0.00 hours while that of the SLO diet 9.20 hours and the ELO diet was 11.40 hours. Trained panelists determined fish fed FO had a significantly higher aroma intensity and significantly lower aroma desirability and overall acceptability than those fed SLO. The rancid aroma and flavour of the FO-fed fish was significantly higher than fish fed the other treatments (P < 0.05). Consumer panelists found no significant differences between the sensory attributes of fish fed the four experimental diets and exhibited no preference between treatments (P > 0.05). Fillets from fish fed FO had significantly higher values than the other three treatments for redness (3.59 vs values between 1.86 and 2.07) and yellowness (25.35 vs values between 20.51 and 21.22) (P < 0.05). Addition of antioxidants to linseed oil improves its oxidative stability during storage and processing and results in fish fillets with fatty acid composition and consumer acceptance equal or superior to fish fed fish oil.

An experiment was conducted to determine the effect of addition of antioxidants or encapsulation of linseed oil on the oxidative stability of linseed oil and the effect on growth and fatty acid composition of rainbow trout fed these products. Four diets differing only in their lipid sources were prepared by cold extrusion: 1) fish oil (FO), 2) linseed oil (LO), 3) linseed oil (980 g/kg) stabilized with vitamin E (7.5 g/kg) and butylated hydroxytoluene (BHT) (12.5 g/kg) (stabilized linseed oil; SLO) and 4) linseed oil (350 g/kg) containing vitamin E (7.5 g/kg), BHT (12.5 g/kg) and encapsulated in a coating material primarily consisting of hydrogenated palm oil (630 g/kg) (encapsulated linseed oil; ELO). Diets were fed twice daily to rainbow trout to apparent satiation (n=22 / replicate; 7 replicates per treatment) during a 168 day growth trial. Following the growth trial, the fish were humanely euthanized by a sharp blow to the cranium and analyzed for fatty acid composition, thiobarbituraric reactive substances (TBARS), fillet colour and sensory attributes (trained and consumer panels). There were no significant differences between treatments on any of the growth parameters investigated or TBARS levels of fish fillets. Omega-3 polyunsaturated fatty acids of trout fed LO were significantly higher than those fed FO (35.5% of total fatty acids vs. 27.6%) and ELO (28.9%) (P < 0.05). EPA and DHA levels were not significantly different between treatments. Diet samples were stored for 168 days at room temperature in sealed plastic containers. Following storage, the oxidative stability index (OSI) of the FO and LO diets were reduced to 0.00 hours while that of the SLO diet 9.20 hours and the ELO diet was 11.40 hours. Trained panelists determined fish fed FO had a significantly higher aroma intensity and significantly lower aroma desirability and overall acceptability than those fed SLO. The rancid aroma and flavour of the FO-fed fish was significantly higher than fish fed the other treatments (P < 0.05). Consumer panelists found no significant differences between the sensory attributes of fish fed the four experimental diets and exhibited no preference between treatments (P > 0.05). Fillets from fish fed FO had significantly higher values than the other three treatments for redness (3.59 vs values between 1.86 and 2.07) and yellowness (25.35 vs values between 20.51 and 21.22) (P < 0.05). Addition of antioxidants to linseed oil improves its oxidative stability during storage and processing and results in fish fillets with fatty acid composition and consumer acceptance equal or superior to fish fed fish oil.

Fresh beef packaged in high-oxygen modified atmosphere packaging (MAP) has longer red color stability than beef in oxygen-permeable polyvinyl chloride (PVC) film. However, fresh beef in high oxygen becomes rancid by 10 days storage at 2°C. Thus the objective of this study was to evaluate the effectiveness of various antioxidants (milk mineral, MM; sodium tripolyphosphate, STP; vitamin E, E) on color and thiobarbituric acid (TBA) values of ground chuck stored in 80% oxygen MAP for 14 days at 1° C. A preliminary experiment was also done to determine the effect of raw meat history (surface area during storage and storage temperature) on stability of ground beef in 80% oxygen MAP. For the preliminary experiment, select beef clods ( 48 hrs postmortem) were cut 11 into trim or coarsely ground and stored frozen or at 2°C in vacuum packaging (VP) for 30 days. Raw meat was then finely ground and wrapped in PVC film or in 80% oxygen. For experiment 2, fresh beef clods were coarsely ground and antioxidants (0.75 or 1.5% MM; 0.25 or 0.5% STP; 50 or J 00 ppm vitamin E) were added, followed by fine grounding and packaging in 80% oxygen MAP. Thiobarbituric acid assay was performed as a measure of rancidity. Hunter color L*, a*, b* values were measured on raw samples through the packaging film. Trim history greatly affected stability of beef in 80% oxygen MAP. VP refrigerated trim yielded ground beef with low oxidative and color stability compared to frozen trim. In comparison of antioxidants, 0.75% MM gave highest redness values (13-15) and lowest TBA values (< 0.5) after storage of ground beef in 80% oxygen MAP for J 4 days. STP-treated beef also had low TBA values(< 0.5) at 14 days storage but samples were less red (a* of J 0-J 2) than MM- treated samples. Samples with E were slightly better than controls, with redness values of 7.9 and J0.8, respectively. Thus, iron-chelating agents (MM and STP) were very effective for preventing rancidity and improving color stability in ground beef packaged in a high oxygen atmosphere.

Magister Scientiae - MSc (Biotechnology) / Brassica napus is a plant that is used for human and animal consumption. This plant is also used for phytoremediation due to its relatively higher level of heavy metal tolerance. In South Africa, mining is one of the main drivers of the economy. One of the major negative environmental impacts of mining is heavy metal contamination. Soil metal content can rise to levels that are quite high and can even have a negative impact on the yields of B. napus crop. The glucosinolate-myrosinase system of B. napus is a system that is used as defence against biotic stressors. Indole glucosinolate breakdown products have been proven to enhance the antioxidant capacity of plants. Some have also shown growth promoting properties in plants. We studied the effect of exogenous DIM on B. napus and it role in Zr induced heavy metal stress. Germination percentages revealed that DIM increased germination, Zr application decreased germination and the DIMZr treatment reversed the negative impact of Zr application on B. napus. The effect of treatments on the biomass of B. napus was assessed by determining the dry weights. Results show that exogenous DIM improves biomass. Zr application decreased biomass and DIM-Zr treatment ameliorated the effect of Zr application. / 2020-08-31

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...