Designing an adjustable ergonomic laptop desk and its evaluating by RULA and NERPA methods.

Background: Using a computer may lead to pain in wrists, neck, and back. In addition, adopting various body postures like sitting cross-legged, semi-fowler's position, and putting the laptop on the leg may lead to the development of persistent and irreversible discomfort.

Objective: The purpose of this research is to design and build an adjustable ergonomic laptop desk based on the anthropometric characteristics of students in the age range of 20 to 30 years and to evaluate its efficiency using RULA and NERPA methods.

The Effect of Sleep Quality and Mental Fatigue on the Learning Rate of Shift Workers with Fast Shift Work Rotation.

Background: Modern industrial societies are always prone to errors and accidents due to complex devices, multitasking, and shift work jobs. Therefore, behavioral tests in learning and memory are necessary to evaluate employees' perceptions to examine the brain's information processing and the physiological and psychological aspects of memory disorders.

Materials And Methods: In this study, the effect of fast shift rotation, sleep quality, and mental fatigue on individuals' learning and memory was investigated using a maze device.

Acoustical role of ear canal in exposure to the typical occupational noise levels.

Exposure to noise associated with injuries has become a public health issue in recent years. This study aimed to show the role of the acoustical structure of the ear canal on the typical occupational sound pressure levels at different frequencies. This cross-sectional study was done on 20-30-year-old participants.