Search Results

You are looking at 1 - 10 of 18 items for :

  • Chemistry and Chemical Engineering x
  • All content x
Clear All

Abstract  

Organic matter associated with rocks was examined by means of thermal analysis using a new methodology in oxidising conditions. This procedure has been named “Oxyreactive Thermal Analysis” (OTA). The OTA results presented in this study characterise samples from sedimentary rock complexes in terms of their age, and of variations in the associated organic matter arising from different precursors and degree of severity of subsequent transformation processes to which it has been subjected. The results of the OTA method make it possible to estimate the temperature of maturation, to describe the process of evolution of the organic matter, and to distinguish genetic features of its carbonised and metamorphosed products.

Restricted access
Progress in Agricultural Engineering Sciences
Authors: Lien Phuong Le Nguyen, Vivien Horváth, Mai Sao Dam, Géza Hitka, Tamás Zsom, and Zoltán Kókai

This work was aimed to investigate the effect of 1-methylcyclopropene (1-MCP), ethylene absorber (EA), ozone alone or in combination on melon quality during storage. Ethylene production, respiration rates, acoustic firmness, surface color, chilling injury, and disease severity of melon were determined. 1-MCP treated fruits and non 1-MCP treated fruits were stored with sachets of ethylene absorber containing KMnO4 or ozone at 0.1 ppm/h during 10 days at 5 °C and subsequent 4 days at 20 °C. Melons treated with 1-MCP were firmer than the rest of the samples during storage. In addition, 1-MCP reduced the yellowing of melon rind compared to other treatments. The combination of 1-MCP and EA did not offer any additional effect in comparison with 1-MCP alone. There was no significant difference between fruits stored with ethylene absorber, ozone and control samples. Ozone treatment during cold storage decreased disease severity, however, fruits exposed to ozone had more serious decay throughout storage at 20 °C, probably due to the unclean air in the chamber.

Restricted access

Abstract  

Hair samples of mildly mentally retarded (LR), moderately mentally retarded (MR), severely mentally retarded (SR) and normal children were collected and measured, using neutron activation analysis and X-ray fluorescence to determine the concentrations of Al, Sb, As, Ca, Cu, I, Fe, Pb, Mg, Mn, Hg, K, Sr, S, V and Zn. The groups of children were of ages between 5 and 13. Difference in the mean concentration of each element between groups was tested by Student"s t-test. No trend, either decreasing or increasing, has been established as the degree of severity increased from normal to SR children, except for the case of Cu. The present work may shed some light in the interpretation of findings on the effects of trace elements on neurobehavioral functions.

Restricted access

Abstract  

Cumene hydroperoxide (CHP) is classified as a flammable hazard in NFPA 43B. Fires or explosions induced by thermal hazards ascribed to the unstable hydroperoxyl or peroxyl groups are often reported. This sequence studies is aimed at the decomposition phenomena associated with the reactive and incompatible characteristics of CHP mixed with alkaline solutions. Various alkalines were used for comparing the relative impact of bases and effects on concentrations. Exothermic onset temperatures and heats of decomposition of these incompatible mixtures were performed by differential scanning calorimetry (DSC). Comparisons of exothermic onset temperature, peak power, heat of decomposition, etc., were assessed to verify the severity of incompatible hazards in these systems. When mixed with a small amount of the hydroxides (in the production or storage of CHP), CHP will be more labile or unstable because of lower exothermic temperature. In addition, to elucidate the final products and propose mechanisms of the reaction of CHP mixed with alkaline solution, the analytical results were carried out by GC/MS and IR. The exhibited reactivity was complicated and significantly affected by the alkaline solutions. The reaction schemes have been proposed in this study. These results are especially important in process safety design for producing CHP and its related compounds, such as phenol, α-cumyl alcohol (CA), acetophenone (AP), and dicumyl peroxide (DCPO).

Restricted access

decreases infiltration and increases runoff and erosion. The magnitude of the change in physical properties depends largely on the severity of fire, the amount of vegetation destroyed, forest floor consumed, heating of the soil, area burned and length of

Restricted access

Fiala , K. , Blanka , V. , Ladányi , Z. , Szilassi , P. , Benyhe , B. , Dolinaj , D. , Pálfai , I. , ( 2014 ) Drought severity and its effect on agricultural production in the Hungarian-Serbian cross-border area . Journal

Open access
Journal of Thermal Analysis and Calorimetry
Authors: Susan Moreno-Molek, Salaam Saleh, Druthiman Reddy Mantheni, Manik Pavan Kumar Maheswaram, Tobili Sam-Yellowe, and Alan T. Riga

cytokines determine malaria severity in Plasmodium falciparum -infected patients from endemic areas of Central India . J Infect Dis . 2006 ; 194 : 198 – 207 . 10.1086/504720 . 3. Armah

Restricted access

potential public health hazard. The risk of foodborne disease is a combination of likelihood of exposure to the pathogen, the likelihood of infection resulting in illness, and the severity of the illness. This leads to increased pressure on the food

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Abduljelil Iliyas, Kelly Hawboldt, and Faisal Khan

precise determination kinetics of this phenomenon to assess its risks and to design mitigation measures. Thermal risks of runaway reactions, such as self-heating, are characterized by their severity in terms of adiabatic temperature rise (Δ T AD ) and

Restricted access

deaths in 1 year was about 445 [ 5 ]. The severity has threatened the survival and development of fireworks and crackers industry [ 2 ]. During the process of production, storage, transport and setting off of fireworks and crackers, the chemical reaction

Restricted access