Teenagers with smartphones spend more time online, as well as at night, which can affect their sleep. The University of Bern conducted a study on the use of digital media at night to increase the risk of sleep and depression, which surveyed more than 300 students. The research results have been published in the journal Youth.
Since the popularity of smartphones in 2007, most teenagers today have smartphones. Thanks to the convenience of wireless network connection and the low cost of Internet access, teenagers can spend more time online and spend less money communicating with their peers, such as via WhatsApp, which profoundly changes their digital media usage patterns. .
The University of Bern study investigates the differences in the use of digital media between teenagers using smartphones and peers using ordinary mobile phones. 162 girls and 200 boys from 12-17 years old in northwestern Switzerland participated in the survey. The results show that teenagers using smartphones spend twice as much time online as teenagers using regular mobile phones, averaging two hours to one hour. In addition, they send more text messages, and the gap is even more disparate. On average, the number of text messages sent reaches 85:7.
The most obvious difference found in the study was at night, after the teenagers went to bed. Only 17% of smartphone users turn off the power or turn the phone into silent mode, and 47% of regular mobile phone users do this. In addition, smartphone users watch videos, surf the Internet, or communicate with friends more frequently at night than teenagers using regular mobile phones. Most importantly, teenagers who use digital media at night increase the risk of sleep deprivation and depression. Therefore, experts recommend that teenagers with sleep disorders or fatigue during the day turn off the phone at least one hour before going to bed.
High-efficiency Centrifugal Blower
Using the latest design, in line with the "three of" standard two rows of large spacing cupola, for the current casting industry commonly used in a cupola, the main structural features for the two rows of vents, row spacing larger, bottom coke burning The formation of two independent combustion zone, by stretching the overheating zone, an increase of hot metal overheating and end coke intense combustion, stable furnace conditions, hot metal temperature, hot metal quality. In accordance with the supply air temperature is divided into cold air, furnace hot air two structures, by mining different temperature air supply to achieve different melting requirements.
Centrifugal blowers are widely used in sewage treatment, smelting blast furnace, coal preparation plant, mine flotation, chemical gas, vacuum and other fields, can also be used to transport other special gases.
Features:
1. Compact structure: beautiful appearance, good stability, easy installation and maintenance.
2. Smooth operation: Optimized design of the impeller to reduce the axial force to a minimum, and efficient impeller, and static and dynamic balance correction, the machine running smoothly, without any damping device in the case of bearings Amplitude ≤0.04mm.
3. Low noise: blower operation, without any mechanical friction, the use of a reasonable blade-shaped line to the sound to a minimum. Centrifugal blower noise is high-frequency noise, as long as there are obstacles, can be noise, so the fan room almost no noise.
4. Oil-free machinery: Blower bearings with grease lubrication, bearing life of more than three years. Fan does not generate oil and gas during operation. Special requirements fans, with molybdenum disulfide lithium grease lubrication bearings.
5. Impeller: Impeller with a special compound linear, reducing internal leakage and improve the volumetric efficiency.
6 easy to adjust: the inlet valve to regulate flow, the outlet valve to regulate the pressure.
7. Drive: usually using a two-pole asynchronous motor, you can also use four-pole motor drive. Depending on the user grid, different voltage motors can be used.
8. Sealing: In addition to each level of import impeller impeller, the interstage and the housing at both ends with a labyrinth seal to prevent gas leaks.
9. Cooling: exhaust bearing housing has two structures, air-cooled and water-cooled, as the impeller on the level of gas compression, resulting in the exhaust casing temperature is much higher than the intake casing. In the exhaust bearing air-cooled or water-cooled device to extend the bearing life.
10. Bearing temperature control alarm: fan accessories with temperature control box, connected to the bearing through the PT100 resistance, when the bearing temperature exceeds the set temperature, the temperature control box will automatically alarm.
11. Transmission: a coupling drive, belt drive, gearbox drive three. According to different equipment and technology, choose a different transmission
High-Efficiency Centrifugal Blower
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