The impact of mining activities on environmental and human health has become a matter of serious concern. Human health and vegetation is affected by decline in the biological, physical, and chemical quality of the environment. On-site pollution in coal mines due to dust, gases, noise, and polluted water is receiving increasing attention because it is affecting coal miners’ health as well as those living in close proximity. Toxic pollutants released in vicinity by such processes include lead, nickel, chromium and cadmium. Focus of research was on the fate of toxic heavy metals in mining areas to evaluate and compare the heavy metal status in directly exposed persons (coal miners) of two different mining regions of Punjab (Pakistan). High significant difference was observed for cadmium, lead, chromium and nickel in nail and serum samples of coal miners. Comparison of metal concentration in biological samples of chakwal and soon valley area shows that soon valley coal mine area is more polluted than chakwal coal mine area.

In this paper, the feature extraction method based on the WPT (wavelet packet transformation) is proposed according to ERD/ERS phenomenon in the motor imagery EEG signals. The method takes the data of the 2005 braincomputer interface competition as the process object. Firstly, EEG signals are preprocessed. Then the average energy difference of wavelet coefficients in the specific frequency bands between C3 and C4 channels extracted with WPT is taken as feature vector. Finally, BP neural network is adopted to classify motor imagery EEG signals of right and left hands.

Organic reactions are typically carried out in the presence of solvents. Isolation of the pure products requires separation and purification steps, which result in a substantial decrease in yield and can be environmentally hazardous processes. A simple and efficient way to increase yields and reduce environmental impact is to conduct the reaction in the absence of solvent, which includes solvent free or solid-state reactions. Solvent-free organic reactions have drawn great interest, particularly from the viewpoint of green chemistry, and environmentally friendly solvent-free reactions have been investigated widely. Due to enormous advantages of solvent free reactions, various solvent free approaches are being discovered for ecofriendly synthesis of many compounds. Metal oxide nanoparticles in the form of nanocatalyst have emerged as viable alternatives to conventional materials in various fields of chemistry and attracted marvelous interest of chemists. This is because the activity of the catalyst resides in the exposed portion of the particles by decreasing the size of the catalyst, advantages such as more surface area would be exposed to the reactant, only negligible amount would be required to give the significant result and selectivity could be achieved, thereby, eliminating the undesired products. The nanocatalyst is inexpensive, stable, can be easily recycled and reused for several cycles with consistent activity. The current review enlists the various types of transition metal oxide nanoparticles involved in catalysis of the organic synthesis.