Performance assessment of gasification reactors for sustainable management of municipal solid waste.

The issue of waste management has received considerable critical attention due to the increase of waste generation worldwide. One of the solutions for waste disposal that has been widely implemented is through the use of the landfill due to its economic benefits. Landfill, however, results in many adverse impacts on the environment and human health. Recycling can extract some useful materials from waste, however not every waste can be recycled and a significant volume of waste, particularly the municipal solid waste (MSW) goes to landfill even though it has extractable energy potentials. Extraction of energy from MSW has been a key focus of research due to the scope of energy recovery, environmental and economic benefits. The principal concept of waste to energy is to convert waste into energy through thermal and/or biological processes. In addition, thermochemical processes such as gasification have been found as a promising technology offering several benefits. This paper presents a critical assessment of waste to energy gasification technology for MSW on processing, energy recovery, environmental performance and economic perspectives. These aspects have been analyzed for the landfill as well. The review also explored and identified suitable simulation tools for optimizing gasification. Subsequently, an assessment and comparison of different gasification reactors were carried out which indicate that the plasma gasification can be a feasible technology for MSW management due to higher energy efficiency (816 kWh/tonne) with minimum emission and lowest residue. Although plasma gasification is an energy intensive application which has relatively higher investment cost, it can be built as a large system (up to several 1000 MW system), which can make it economically competitive too. Other technologies such as; fluidized bed gasifier, fixed bed gasifier also have good energy efficiency (547-571 kWh/tonne) however, they contribute to higher CO2 emission. Considering overall waste management, it was found that gasification technology is beneficial to economy, environment and energy extraction compared to the landfill option. A number of tools and their relevant properties have been identified to develop appropriate gasifier model. It is expected that this study will advance further research and innovation that will be helpful to manage waste efficiently as well as to improve the environment.

4-4-(Anilinomethyl)-3-[4-(trifluoromethyl)phenyl]-1H-pyrazol-1-ylbenzoic acid derivatives as potent anti-gram-positive bacterial agents.

A collection of potent antimicrobials consisting of novel 1,3-bis-benzoic acid and trifluoromethyl phenyl derived pyrazoles has been synthesized and tested for antibacterial activity. The majority of trifluoromethyl phenyl derivatives are highly potent growth inhibitors of Gram-positive bacteria and showed low toxicity to human cultured cells. In particular, two compounds (59 and 74) were selected for additional studies. These compounds are highly effective against Staphylococcus aureus as shown by a low minimum inhibitory concentration (MIC), a bactericidal effect in time-kill assays, moderate inhibition of biofilm formation as well as biofilm destruction, and a bactericidal effect against stationary phase cells representing non-growing persister cells. Multistep resistance assays showed a very low tendency for S. aureus and Enterococcus faecalis to develop resistance through mutation. Additionally, in vivo mouse model studies showed no harmful effects at doses up to 50 mg/kg using 14 blood plasma organ toxicity markers or TUNEL assay in liver and kidney. Investigations into the mode of action by performing macromolecular synthesis inhibition studies showed a broad range of inhibitory effects, suggesting targets that have a global effect on bacterial cell function.

Proteome analysis of rice tissues by two-dimensional electrophoresis: an approach to the investigation of gibberellin regulated proteins.

Protein databases constructed using high-resolution two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) were used to explore the proteome expressed in various rice tissues. Proteins from leaf sheath, root, and cultured suspension cells were systematically analyzed using 2D-PAGE, mass spectrometry and Edman sequencing, followed by database searching. In all, 79 of the 431 spots detected by 2D-PAGE in the leaf sheath, 73 of the 508 spots in the root and 140 of the 962 spots in the cultured suspension cells could be identified. Protein lists were constructed for each tissue and used to investigate the effects of gibberellin (GA) treatment. In the leaf sheath, root and cultured suspension cells, 8, 21, and 14 of the identified proteins, respectively, were regulated by GA. These proteins included polypeptides involved in general metabolism, energy production, transcriptional regulation and signal transduction in the leaf sheath; in metabolism and defense in the root; and in metabolism, energy production, cell growth, defense and signal transduction in the cultured suspension cells. These results indicate that the proteome databases assembled in these studies will be useful for the rapid assessment of changes in protein content in specific tissues, and that proteins regulated by GA may play a significant role in tissue growth.