Effects of Long-Term Soaking on the Load-Bearing Capacity of Bitumen-Treated Saline Sabkha Soil Subgrade

This study delves into the potential of using modified sabkha soil, a low-quality material, as a cost-effective solution for road construction in Kuwait, a country grappling with resource limitations. The research evaluates the effects of adding different percentages of bitumen (0%, 4%, 8%, and 10%) to sabkha soil samples, specifically looking at their load-bearing capacity under long-term soaking conditions. The findings indicate that adding up to 8% bitumen enhances the soil's geotechnical properties and its load-bearing capacity. However, any further addition leads to a decline in these properties. Importantly, the soil's load capacity shows significant improvement under soaked conditions. These encouraging laboratory results suggest that utilizing waste sabkha soil could pave the way for effective soil waste management techniques, thereby addressing environmental concerns related to sabkha soil disposal

Optimization of chloroxylenol degradation by Aspergillus niger using Plackett-Burman design and response surface methodology

Chloroxylenol is a very toxic phenolic derivative and it represents potential hazard towards human health and to the environment. Aspergillus niger, local isolate, is an efficient fungus to degrade 99.72% of 2 mg/L of chloroxylenol after 7 days of fermentation. It also has a high capacity to degrade 91.83% of higher chloroxylenol concentration of 20 mg/L after 6 days of incubation on mineral medium amended with 2 g/L of glucose. Statistical experimental designs were used to optimize the process of chloroxylenol degradation by the fungus. The most important factors influencing chloroxylenol degradation, as identified by a two-level Plackett-Burman design with 11 variables, were NaCl, (NH4)2SO4, and inoculums size. Response surface analysis was adopted to further investigate the mutual interactions between these variables and to identify their optimal values that would generate maximum chloroxylenol degradation. Under the optimized medium compositions and culture conditions, A. niger was able to degrade completely (100%) chloroxylenol (20 mg/L) after 134.6 h of fermentation. The predicted values of Plackett-Burman conditions and response surface methodology were further verified by validation experiments. The excellent correlation between predicted and experimental values confirmed the validity and practicability of this statistical optimum strategy. Optimal conditions obtained in this work laid to a solid foundation for further use of A. niger in treatment of high strength chloroxylenol polluted effluents. So, the optimized conditions were applied to bioremediate crude sewage containing 27.8 mg/L of chloroxylenol by A. niger. The fungus efficiently degraded chloroxylenol after 8 days of fermentation.Key words: Chloroxylenol degradation, Aspergillus niger, Plackett-Burman design, Response surface methodology

Synthesis, Characterization and Antitumor Activity of Some New Oganotellurium Compounds Containing Azomethine Group, Part One

New tellurated schiff bases were synthesized by the reaction of the corresponding mercurated Schiff  bases compounds A1-A3 with tellurium tetrabromide in 1:1 mole ratio and  that  gave organyltellurium tribromides  A4-A6.  On the other hand, when mercurated schiff bases and tellurium tetrabromide brought  together in 2:1 mole ratio gave diorganyltellurium dibromides compounds A10-A12 followed by reduction with hydrazine hydrate gave new diorganyl tellurides A13-A15.  Reduction of compounds A4-A6 by  hydrazine hydrate gave new ditellurides A7-A9.  All compounds were characterized by elemental analysis, IR, 1H , 13C NMR, HSQC-NMR and mass spectra.  Invitro anti-tumor bioactivity of some compounds were tested.Â

ENVIRONMENTAL PROBLEMS OF SUSTAINABLE DEVELOPMENT AND IMPROVEMENT OF URBAN AREAS AND WAYS OF THEIR DECISION

In this article features of influence of an ecological factor of development of urban areas on formation of improvement of the cities, the most expedient ways of providing a favorable ecological situation of urban areas, major factors interfering development of improvement of urban areas and offers of decisions for achievement of the favorable ecological environment in the cities are investigated

CONCEPTS OF DEVELOPMENT OF URBAN AREAS IN DEVELOPING COUNTRIES

In this article the problems of development of urban areas from the point of view of economy, the main tendencies of city building, the main criteria of sustainable economic development of urban areas and major factors interfering effective complex development of urban areas are researched

Novel Marine Compounds: Anticancer or Genotoxic?

In the past several decades, marine organisms have generously gifted to the pharmaceutical industries numerous naturally bioactive compounds with antiviral, antibacterial, antimalarial, anti-inflammatory, antioxidant, and anticancer potentials. But till date only few anticancer drugs (cytarabine, vidarabine) have been commercially developed from marine compounds while several others are currently in different clinical trials. Majority of these compounds were tested in the tumor xenograft models, however, lack of anticancer potential data in the chemical- and/or oncogene-induced pre-initiation animal carcinogenesis models might have cost some of the marine anticancer compounds an early exit from the clinical trials. This review critically discusses importance of preclinical evaluation, failure of human clinical trials with certain potential anticancer agents, the screening tests used, and choice of biomarkers

AC losses in superconducting niobium

This thesis is concerned with measurements of alternating field losses in cylindrical rods of niobium in its superconducting state. Six samples have been investigated each with a different surface condition, Magnetization measurements of the samples have been studied which show the effect of the surface condition on the first critical magnetic field H[sub]c₁. The effect of the surface on flux pinning are discussed. Power losses have been studied experimentally for single crystal niobium and for polycrystalline niobium each with three different surface conditions in order to study the effect of the surface properties on these ac losses. A wattmeter technique was developed for measurements of power losses in the samples. Experiments were conducted over a range of applied fields at 50 Hz and at 4.2 K. This technique will be described together with the experimental results. The results will be compared with predictions from a modified critical state theory and their significance discussed. The critical current density has been measured for each sample using a method based on the measurements of the power dissipation in a small modulating field, in the presence of a steady bias field. The technique will be described together with experimental results. The shielding field △H in the mixed state has been studied for the samples. The technique and the results will be discussed for each sample

ENVIRONMENTAL PROBLEMS OF SUSTAINABLE DEVELOPMENT AND IMPROVEMENT OF URBAN AREAS AND WAYS OF THEIR DECISION

In this article features of influence of an ecological factor of development of urban areas on formation of improvement of the cities, the most expedient ways of providing a favorable ecological situation of urban areas, major factors interfering development of improvement of urban areas and offers of decisions for achievement of the favorable ecological environment in the cities are investigated