mechanical weeding is one of the non-chemical methods to control weeds. in this paper a ‎new mechanism has been presented for mechanical cultivation. the machine works based on ‎the manual tools operation, which farmers still use in small scale for weeding and consists of a ‎number of four-bar linkage mechanisms. each mechanism consists of a blade which moves ‎forward (active course) and backwa...

hypersensitivity reactions to natural rubber latex have increased recently, especially among people with high exposure to latex allergens. hypersensitivity reactions to latex are related to many conditions like occupational asthma. our study was performed to determine the prevalence of hypersensitivity to natural rubber latex and potential food cross reactions in operation room personnel in shi...

This paper discusses the application of the plantwide control design procedure of Skogestad [Skogestad, S. (2004a). Control structure design for complete chemical plants. Computers and Chemical Engineering, 28, 219–234] to the ammonia synthesis process. Threemodes of operation are considered: (I) given feed rate, (IIa) maximum throughput, and (IIb) “optimized” throughput. Two control structures...

Batch distillation processes are widely used in chemical industry. In this work, we consider the optimization of such processes by simulated annealing. Although this method is stochastically in nature, it has two evitable advantages: it can be readily connected to highly sophisticated simulation codes and it converges towards a global optimum. According to the characteristics of batch distillat...

This work studied the combination of a chemical coagulation/flocculation step with an aerobic biological process, using feed-batch operation, to treat real paint manufacturing wastewater (PMW). The results indicate that the combination of coagulation flocculation and biological process is an efficient alternative in the treatment of PMW. For initials COD of 18590 mg/L, BOD of 1492 mg/L and colo...

The drive to develop better electrochemical energy storage devices requires the development of not only new materials, but also better understanding of the underpinning chemical and dynamical processes within such devices during operation, for which new analytical techniques are required. Currently, there are few techniques that can probe local composition and transport in the electrolyte durin...

Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to ...

The paper deals with investigations concerning the construction of sensors based on a quartz crystal microbalance (QCM) containing a TiO2 nanostructures sensor layer. A chemical method of synthesizing these nanostructures is presented. The prepared prototype of the QCM sensing system, as well as the results of tests for detecting low NO2 concentrations in an atmosphere of synthetic air have bee...

In nowadays’ market conditions in the chemical industry, multi-product facilities, either multi-purpose batch processes or continuous processes operated in production campaigns, become more and more common. Hence, the operation of these processes does not only require optimal stationary but also optimal dynamic modes of operation. Dynamic optimization is considered a powerful tool to determine ...

The interplay between retrocausality and the time-reversal symmetry of the dynamical law of quantum mechanics underscores the significance of the measurement dynamics with the use of indivisible and discrete quantum particles to be mediated. One example of empirical evidence demonstrating the significance of retrocausality going along with time-reversal symmetry is seen in the operation of a re...