53 research outputs found
Synthesis and cytotoxicity evaluation of thiazole derivatives obtained from 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile
Reactivity of 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile towards thioglycolic acid resulted in thiazole derivative 1. The latter reacted with different chemical reagents to give thiazole, pyrano[2,3-d]thiazole and thiazolo[4,5-d]thiazole derivatives. Cytotoxicity effects of the newly synthesized products against six cancer cell lines, namely, human gastric cancer (NUGC), human colon cancer (DLD-1), human liver cancer (HA22T and HEPG-2), human breast cancer (MCF) and nasopharyngeal carcinoma (HONE-1) as well as against a normal fibroblast cell (WI-38) were evaluated. The study showed that the 4,5,6,7 tetrahydrobenzo[b]thiophene derivatives 6a, 7, 8a,b, 9b and 10b,c were the most active compounds. Their potencies were attributed to the presence of the electron withdrawing groups
Chemical analysis of different parts of date palm (Phoenix dactylifera L.) using ultimate, proximate and thermo-gravimetric techniques for energy production
The objective of the study was to analyze chemical structure of date palm ( Phoenix dactylifera L.) by employing ultimate, proximate and thermo-gravimetric techniques. Samples from different anatomical parts of date palm, namely trunk, frond base, frond midrib, leaflets, coir, fruit stem, date stone, and fruit empty bunches were considered for the experiments. Based on the findings in this work palm leaflet samples gave the highest amount of extractives content (32.9%), followed by date palm stone specimens with 31.5%. Cellulose content values of 32.8% and 47.5% were obtained for date palm stone and palm coir samples, respectively. Overall the hemicellulose contents of all samples were relatively similar to those of typical wood or non-wood lignocellulosic materials with the two exceptions of palm coir and palm leaflets. Both palm coir and palm leaflet specimens had 12.6% and 16.1% hemicellulose content. Volatile matter values of 74.3% and 87.5% were determined for leaflets and fruit empty bunch samples. The ash content of the samples ranged from 1.4% for date stone to 15.2% for palm leaflet samples. The thermal decomposition was completed below a temperature of 500 °C with an exception of those samples taken from palm leaflets. Taken together the data indicate that date palm stone and palm coir revealed could be more viable for renewable energy production than the other specimens considered in this work.Peer reviewedNatural Resource Ecology and Managemen
Development of leach-resistant boron compounds for wood protection in exterior applications in Egypt
Effects of polyvinyl alcohol on leachability and efficacy of boron wood preservatives against fungal decay and termite attack
International audienc
Effect of heat treatment intensity on wood chemical composition and decay durability of Pinus patula
International audienc
Developing Biocomposites Panels from Food Packaging and Textiles Wastes: Physical and Biological Performance
The urban solid waste problem has been one of the biggest environmental challenges these days. In this context, developing biocomposites with improved performance by using various sources and wastes has been intensified in the last decades for economic and environmental points of view. In this study, physical behavior, fungal decay and termite attack tests were conducted in laboratory conditions to investigate the performance of composites developed from TetraPak and textile wastes. All the results were compared to standard wood products. The water swelling properties strongly decreased in the manufactured TetraPak composites when compared with the conventional particleboard panels. The fungal decay resistance tests revealed that the stand alone TetraPak based composites were not completely resistant to wood-decaying fungi. A significant amelioration in the decay durability was observed for the manufactured TetraPak composites compared to the standard wood samples. Durability classes were determined according to the criteria given in the European standard (CEN/TS15083-1). Interestingly, the data indicated that the increment of the wool waste proportion in the produced boards lead to a significant enhancement counter the test fungi. The results of termite screening test showed further considerable resistance for whole TetraPak based composites against termites when compared to traditional wood samples. Such panels could be an available alternative without any additives for wood based composite structures and it can be used in a wide range of applications
Effect of extractives on conferred and natural durability of
• Identification of extractives present in Cupressus lusitanica
heartwood has been conducted using GC-MS analyses. The chromatogram of
toluene/ethanol extracts indicated the presence of large amounts of benzaldehyde and
numerous terpenic compounds such as cedrol, agathadiol, epimanool, bornyl acetate,
α-cedrene and β-cedrene.
• The effect of these extractives on the natural durability of cypress wood was
investigated on heart wood blocks exposed to pure culture of Poria placenta
before or after solvent extraction. Weight losses revealed severe fungal
degradations on the extracted blocks compared to unextracted ones.
• Efficiency of heartwood extractives as inhibitors of the growth of Poria
placenta on malt/agar test confirms their contribution to cypress natural
durability.
• Cypress blocks were treated at 240 °C for different times to reach different levels of
thermo-degradation to evaluate effect of heat treatment on fungal durability. Results
indicate that evaporation of volatile extractives during the first few minutes of heat
treatment contribute to decreased wood durability, while longer treatment times lead to
the expected improvement of durability.
• This study suggests that the content of extractives, which may be modified during wood
drying or weathering processes, could be the origin of the conflicting data described in
the literature concerning cypress natural durability
Prediction of the decay resistance of heat treated wood on the basisof its elemental composition
International audienc
- …