With progress in mineral processing technologies, particle size classification equipment has also been changed to satisfy the needs of modern plants. Accordingly, design, manufacturing and utilizing of banana screens in mineral processing plants have led to increased screening efficiency at industrial scale. Banana screen is an important invention occurred in past decade which increases screeni...

background : due to rapid advances in modern technologies such as telecommunication technology, the world has witnessed an exponential growth in the use of digital handheld devices (e.g. smartphones and tablets). this drastic growth has resulted in increased global concerns about the safety of these devices. smartphones, tablets, laptops, and other digital screens emit high levels of short-wave...

In 1850, an article on the origin of epidemic yellow fever and malaria appeared in the Boston Medical and Surgical Journal. The anonymous author referred to earlier reports that "those who slept under musquito [sic] netting escaped the disease" and that "a gauze screen in a window adds much to the security of . . . the occupant of a chamber, in even the most unsound places." These observations,...

Background: It has been shown that short-wavelength blue component of the visible light spectrum can alter the circadian rhythm and suppress the level of melatonin hormone. The short-wavelength light emitted by smartphones’ screens can affect the sleep quality of the people who use these devices at night through suppression of melatonin.Objectives: In this study, we examined the effects of co...

background and purpose: many workers are exposed to workplace hazards. many occupational diseases are preventable by personal protective devices (ppds). though many workers do not use ppds or their protection by ppds is not sufficient. this study was designed to assess the quality of ppds usage among industrial workers. materials and methods: in a cross-sectional study, 648 workers from four ma...