The use of biodosimetry to measure the UV-C dose delivered to a sphere, and implications for the commercial treatment of fruit

Commercialization of UV-C treatment of horticultural produce in order to induce beneficial responses in the produce following treatment requires both accurate dose delivery and a method of treating large quantities of produce efficiently. Furthermore, it has long been assumed that such effects require the entire surface of the horticultural commodities - typically fruit - to be exposed to UV-C. This has invariably been achieved by manually rotating the fruit in a UV-C field whilst reducing the dose delivered at each rotation in direct proportion to the number of rotations. However, the resulting UV-C dose distributions achieved under these circumstances are generally not reported in the literature. In the work described here a polystyrene sphere (Dia., 70 mm) was used to simulate fruits such as tomatoes, apples, peaches etc., that have an approximately spherical form in order to provide a means of measuring the total doses of UV-C accumulated during treatment and comparing such estimates to theoretically-derived ones. This was achieved using dosimetry based on spores of B. subtilis in which spore-impregnated membranes were attached to the surface of the sphere. The fraction of spores surviving exposure was used to estimate dose from a dose-response curve for the spores. Under irradiation conditions leading to a theoretically calculated dose of 10.6 J, spore dosimetry yielded estimates of 9.1, 10.7 and 6.1 J for UV-C delivered in respectively, one, two or four exposures. In the case of exposure of the sphere during continuous mechanical rotation for the same length of time (80 s) a value of only 3.5 J was obtained. Irradiation conditions resulting in the spores being subject to intermittent exposure to UV-C led to dose estimates below the theoretically derived ones. The circumstances under which spore dosimetry can be used to obtain surface dose distributions are discussed

Numerical Study of Reinforced Concrete Beam by Using ABAQUS Software

Cracks are serious problems in the structural characteristics of a concrete structure due to several failure modes such as, flexural and shear. Reinforced concrete behaviour is complicated, and for a realistic simulation of such behaviour a prober material modelling has to be used.  In this work an attempt has been made to simulate concrete and embedded reinforcement steel to predict the crack propagation in RC beam using a plastic damage behaviour by ABAQUS software. The proposed modelling has been validated against experimental results found in the literature. The results have shown that displacement associated with ultimate load is in a good agreement with experiment, as well as the failure load. The crack pattern indicated that the cracks will start from the tension zone in the bottom of RC beam and extended to top of beam

Effect of strong electrolytes on edible oils part III: viscosity of canola oil in 1,4-dioxane in the presence of HCl, NaOH and NaCl at different temperatures

Effect of strong electrolytes on the viscosity of canola oil in 1,4 dioxane was undertaken. The viscosity of oil in 1,4 dioxane was found to increase with the concentration of oil and decrease with rise in temperature. Strong electrolytes reduce the rate of flow of oil in 1,4 dioxane. It was noted that amongst these electrolytes, NaOH is more efficient reducing electrolyte than HCl and NaCl. The study was also extended in terms of ion-ion and ion-solvent interactions. The values of Jones-Dole coefficients (A and B) were evaluated graphically. The increase in negative values of A-cefficient with temperature is due to agitation of the molecules at higher temperature, dissociation and partial association of electrolytes in 1,4 dioxane. The positive values of B-cefficient show that these electrolytes behave as structure breaker in 1,4 dioxane. Distortion of the solvent structure is not appreciable (small), which resulted in the positive values of B-coefficient. Fluidity parameters were also evaluated and the change in these values with temperature and concentration of oil shows that the electrolytes behave as structure breaker. The energy of activation, latent heat of vaporization and molar volume of oil were also evaluated and discussed. Journal of Applied Sciences and Environmental Management Vol. 10(1) 2006: 47-5

Effect of strong electrolytes on edible oils part II: vViscosity of maize oil in 1,4-dioxane in the presence of HCl, NaOH and NaCl at different temperatures

The effects of strong electrolytes like HCl, NaOH and NaCl on the viscosity of maize oil at various temperatures (298 – 323 K) with the difference of 5 K using 1,4 dioxane as solvent were determined. The viscosity of oil was found to be increased with the increasing concentration of oil and decreases with the rise of temperature. The addition of electrolytes decreases the viscosity of oil although very little which shows that the electrolytes increase the distance between oil molecules and cause the enhancement of rate of flow and the increment of temperature drops the rate of flow of the solutions. Furthermore the concentration of electrolytes increases the viscosity of oil solutions. It is due to the presence of unsaturated ingredients present in the oil and thermal effect. The electrolytes behave as structure breaker. The effect of temperature was also determined in terms of fluidity parameters, energy of activation, latent heat of vaporization, molar volume of oil and free energy change of activation for viscous flow. Journal of Applied Sciences and Environmental Management Vol. 10 (3) 2006: 67-7

Effect of preharvest UV-C treatment of tomatoes (Solanum lycopersicon Mill.) on ripening and pathogen resistance

Treatment with UV-C of tomato fruit on the vine was conducted using a mobile unit that was designed to be conveyed between the rows of tomato plants in a commercial glasshouse. Trusses of fruit both at the ripe and mature green phase were treated with UV-C doses of 3 and 8 kJ/m2. Ripe fruit were picked 8 h after treatment and kept at room temperature for up to 16 d during which colour development and texture were monitored and compared to untreated controls. Mature green fruit treated on the vine with UV-C doses of 3 or 8 kJ/m2 showed only a slight loss in green pigmentation in contrast to the tomato colour index (TCI) of control fruit which increased sharply 5 d after treatment. The TCI of ripe fruit treated with UV-C at a dose of 8 kJ/m2 showed a lag of 10 d before increasing to a final value comparable to that of untreated fruit. Fruit treated with a dose of 3 kJ/m2 did not display a lag but the increase in TCI occurred at a lower rate than for the controls. Firmness remained higher in fruit treated with the highest UV-C dose compared to fruit treated with the lower UV-C dose and controls. Fruit covered with UV impermeable film on the same plants as those that had received a UV-C dose of 3 kJ/m2 had become ripe by day 6 in a manner similar to that of the controls. By contrast, fruit from trusses adjacent to those that had been treated with a UV-C dose of 8 kJ/m2 remained green over the same period of time. Ripe fruit treated as described above were inoculated with spores of Penicillium digitatum after UV-C treatment and their firmness monitored over 12 d. A dose response effect was found with fruit treated at the highest dose remaining firmer than those treated at the lower dose and the controls

Preparation and Characterization of Various Interstitial N-Doped TiO2 Catalysts from Different Nitrogen Dopants for the Treatment of Polluted Water

In this work N-doped TiO2 nano particle photocatalysts were prepared through a sol-gel procedure using three different types of nitrogen dopants urea, diethanolamine (DEA) and triethylamine (TEN). Multiple techniques (XRD, TEM, SEM, EDX, BET, Raman and UV-Visible absorption) were commanded to characterize the crystal structure of N-doped TiO2. The catalytic activity of the N-doped TiO2 under ultraviolet (UV) and visible light irradiation is evidenced by the decomposition of 2-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 are responsible for the visible light catalytic activity. It is suggested that doped nitrogen here is located at the interstitial site of TiO2 lattice. Amongst investigated nitrogen precursors diethanolamine provided the highest visible light absorption ability of interstitial N-doped TiO2 with the smallest energy band gap and the smallest anatase crystal size, resulting in the highest efficiency in 2-cholorophenol degradation. The photocatalytic activity and 2-CP mineralization ability of all N-doped TiO2 can be arranged in the following order:  TiO2/DEA > TiO2/TEN > TiO2/UREA > un-doped TiO2. Keywords: 2-chlorophenol, Photocatalytic degradation, N-doped TiO2, Different Nitrogen Dopants, urea, diethanolamine (DEA), triethylamine (TEN) and Catalytic Activity

Melampomagnolide B Derivatives as Antileukemic and Cytotoxic Agents

Melampomagnolide B is disclosed as a new antileukemic sesquiterpene. A biotin-conjugated derivative of melampomagnolide B was prepared to elucidate its mechanism of action. Prodrugs of Melampomagnolide B are disclosed

An in-depth analysis and modelling of the Shuttle to MILA S-band telemetry link

The S-Band radio frequency (RF) link between the Merritt Island (MILA) Tracking Station and the Space Shuttle launch pads is a critical communication path for prelaunch and launch operations. The proposed siting of the Center for Space Education (CSE) at the Visitor Center required a study to avoid RF line-of-sight blockage and reflection paths. The study revealed the trees near MILA's 9-meter (9-M) antennas are obstructing the optical line-of-sight. The studies found diffraction is the main propagation mechanism. This paper describes a link model based on the Geometric Theory of Diffraction

(11R)-13-[2-(4-Hydroxy­phen­yl)ethyl­amino]-4,5-ep­oxy-11,13-dihydro­costunolide monohydrate

The title compound (systematic name: 12-{[2-(4-hydroxyphenyl)ethyl]aminomethyl}-4,8-dimethyl-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one monohydrate), C23H31NO4·H2O, was obtained by the reaction of tyramine with parthenolide. The configuration of the new chiral center in the title compound is R, establishing the stereospecificity of the amination reaction. The water molecule is disordered over three positions; the site occupancy factors are 0.45, 0.40 and 0.15

(11R,13R)-13-(Tetra­lin-1-ylamino)-4,5-ep­oxy-11,13-dihydro­costunolide

The title compound [systematic name: (12R)-4,8-dimethyl-12-[(1′R)-1′,2′,3′,4′-tetrahydro-1′-naphthyl)aminomethyl]-3,14-dioxatricyclo[9.3.0.02,4]tetradec-7-en-13-one}, C25H33NO3, was formed from the reaction of (1R)-1-amino­tetra­lin with parthenolide in methano­lic solution. X-ray crystal structure analysis determined that the configuration of the new chiral center in the title compound was R