With LPWAN low-power wide-area network such as NB-IoT and LoRa and the current 5G network construction, the vision of the Internet of Everything is carried, and the large-scale deployment of low-power and remote connection of the Internet of Things is solved. There is data display, LPWAN connection is in 2018. The compound annual growth rate will be 109% by 2023, which will open the trillion-dollar IoT market and promote the application of the Internet of Things in vertical areas such as industry, energy, retail, logistics and traceability.
New economy benefits IoT technology to promote industry transformation and upgrading
In recent years, China's new economy has developed more rapidly than expected. Mobile payment, big data, cloud computing, etc. have driven the industrial revolution and product innovation. China has become the most innovative and dynamic market in the world today. The booming of the new economy has opened up the potential for the development of innovative companies with Internet of Things, artificial intelligence and biotechnology as the core, and is expected to expand rapidly. Now the community is actively preparing for the development opportunities released by the new economy.
Looking at the world, the transformation enterprises with AI+IoT as the core have developed rapidly. At the same time, with the integration of biotechnology and artificial intelligence and the Internet of Things, there are unprecedented opportunities for biotechnology innovation companies to emerge. Innovative companies including Haier Biomedical have emerged, using new technologies such as the Internet of Things to boost smart creatures. The arrival of the technological era.
For cyclists, you must wear attractive bicycle helmets when riding out. However, after experiencing wind, rain, sun, rain, and pasting number stickers, it is inevitable that the helmet will gradually become old.However, it is your fault that the helmet is dirty and smelly, and even the EPS edge of the inner shell is potty, which is caused by improper maintenance.
First of all, maintaining the luster of the helmet shell is a contradictory problem, because the luster of the attractive bicycle helmets are due to the ultraviolet rays of the sun and the dust from the surroundings that are attached to our helmets during daily riding, making it lose its former luster. . Although we can't avoid it, at least we have to find a way to make the gloss last longer.
Remember that bicycle helmets should not be exposed to the sun and frequent rain, or they will be glued soon. There is also a cotton cloth moistened with alcohol or white electric oil to wipe the surface of the helmet every time you come back to remove the stains and dust on the surface of the helmet (never use a harder cloth to wipe the helmet shell). You can also put some wax on the helmet to make it more shiny.
For the inner shell EPS, there is no need for maintenance, but as time goes by, the place where there is no outer shell on the edge will be pitted and not as smooth as before. For those places where the depressions are not deep, we can use the screwdriver's shank part to slightly press the depressed areas around the depressions.
Remember to use a screwdriver to select a round rod and press it back and forth. For those places where the depression is deeper, we use the mosquito incense that is used daily to smoke mosquitoes. We first light it, and then use the lighted part to bake it. The EPS will foam as soon as it becomes hot. Remove the mosquito coil when you see the sunken place and the same place.
The lining needs daily cleaning. When removing the inner lining, do not pull it suddenly with great force, it is very easy to tear off the Velcro and the inner lining together. The disassembled inner liner cannot be washed in a washing machine, nor can it be brushed with a brush. This will easily deform the inner liner and lose its elasticity. Just soak it in water with detergent or detergent for a few minutes, rub it a few times with your hands, rinse it with water, and dry it.
Helmets are witnesses that accompany us through every journey worth remembering. As a must-have, the most important attractive bicycle helmets, it is very stressful. So, for your purse and its light, please treat it normally.
PHMB is a disinfectant used in disinfection of swimming pools, hot tubs and contact lenses. According to research, swimming pools have proven to be one of the main vectors of adenovirus eye infection transmission. So, how do we determine whether PHMB is an effective disinfectant for ordinary eye Ad serotypes?
Method
The direct antiviral activity of PHMB was determined by incubating high concentrations of clinical isolates Ad1, Ad2, Ad3, Ad4, Ad5, Ad7a, Ad8, Ad19, and ATCC Ad37 at 30 and 20 PPM at room temperature or 40 degrees Celsius. The PHMB and control medium are left for 24 hours.
Standard plaque assays were performed on the reaction mixture to determine the AdMB concentration after PHMB or control treatment. Logically convert the AD concentration and calculate the Log 10 reduction in titer relative to the control.
Result
At room temperature, for any Ad serotype tested at 30 or 20 PPM, the concentration of PHMB does not produce a decrease of> 10 Log10. However, at 40 degrees Celsius, for Ad1, Ad3, Ad5, Ad8, Ad19 and Ad37, the Ad titer of PHMB at 30 and 20 PPM decreases> 10 Log10, but not for Ad2, Ad4 and Ad7a.
In conclusion
When PHMB is used to disinfect swimming pools and hot tubs, it does not reduce AD concentration at room temperature. When the temperature rises to 40 degrees Celsius, the effect of PHMB reducing Ad concentration is enhanced, but the effect does not cover all tested Ad serotypes.
In swimming pools, PHMB does not seem to be an effective disinfectant against Ad, but only moderately effective in hot tubs.
Tag: PHMB Powder CAS 32289-58-0
There are roughly three types of modified shock absorbers-short springs(helical compression spring), twisted teeth, and pneumatic. Today I will talk about the role of short springs in shock absorption.
Springs, which are common in life, are compressible and expandable. The use of springs in cars can reduce vibration, especially for poor road conditions, allowing the wheels to better contact the ground, increasing comfort and safety.
Progressive spring
This kind of spring adopts a design with inconsistent thickness and density. The advantage is that it can absorb the undulations of the road through the part with a lower elastic coefficient when the pressure is not large, ensuring the riding comfort, and the thicker part when the pressure increases to a certain degree The spring plays the role of supporting the body, and the disadvantage of this spring is that the control feeling is not direct and the accuracy is poor.
Linear spring
The thickness and density of linear springs are unchanged, and the elastic coefficient is a fixed value. This design of the spring can make the vehicle obtain a more stable and linear dynamic response, which helps the driver to better control the vehicle.
Short spring(helical compression spring)
That is the short spring that everyone usually talks about. The length of the short spring is shorter than that of the progressive spring, and it is also thicker. The installation of short springs can effectively reduce the center of gravity of the vehicle body, reduce the roll produced during cornering, make cornering more stable and smooth, and improve vehicle cornering control.
The damping setting of the progressive spring shock absorber is more comfortable, so the short spring and the original shock absorber are not very stable in cooperation. It cannot effectively suppress the rebound and compression of the short spring. When driving on bumpy roads, it will There is a sense of discomfort in jumping.
Replacing the short spring is the most affordable conversion option to reduce the height of the vehicle. Although the replacement of the short spring will improve part of the controllability, but the space for improvement is limited, and if the road conditions of the vehicle are complicated, the shock may be affected in the past.
Tag: Trampoline Spring ; Garage Door Torsion Spring ; Helical Compression Spring ; Garage Door Torsion Springs ; Garage Door Torsion Spring for Rolling Shutter ; Heavy Duty Garage Door Spring
First, the working principle of screw compressor refrigeration unit
Screw refrigeration compressor is a new type of high-speed compressor. The principle of increasing gas pressure is the same as that of piston compressor, which belongs to volumetric compression. At present, twin screw compressors are generally used. Twin screw compressors use two mutually intermeshing screws to make relative rotational movements to compress the gas.
With the rapid development of the refrigeration industry and the improvement of processing methods, screw compressor refrigeration units have developed greatly. The cold storage is gradually becoming larger, the types of units are increasing, the scope of use is expanding, and it is expanding to different application areas.
Driven by the motor, the driving rotor rotates with the motor, and at this time, the driven rotor that is engaged also follows the opposite direction. In the rotor movement, when a pair of meshing grooves of the driving rotor and the driven rotor communicate with the suction duct, sufficient suction is performed. When the rotor continues to rotate, the pair of suction grooves leaves the suction orifice on the suction end face, and the gas in the tooth groove enclosed by the suction and exhaust end seats is isolated from the outside of the casing and begins to be compressed.
The driving and driven rotors continue to rotate, and the tooth peaks of the driving rotor continuously fill the tooth valleys of the driven rotor. Similarly, the tooth peaks of the driven rotor also continuously fill the tooth valleys of the corresponding driving rotor. As a result of the mutual filling, the groove volumes of the respective rotors are gradually reduced, and the gas in the grooves is gradually compressed. When the gas pressure reaches the specified value, the rotor is turned to a position where the groove communicates with the exhaust port to discharge the gas. Such continuous operation, the refrigerant is continuously compressed and discharged from the screw compressor refrigeration unit.
Screw refrigeration compressors inject a large amount of oil during the compression process, which can take away the heat generated during the compression process. At the same time, the oil film is used to seal the gap between the female and male rotors and the gap between the rotor and the cylinder, so that internal leakage losses are reduced.
Advantages and disadvantages of screw compressor refrigeration unit
1. Main advantages
(1) Easy management
The screw compressor refrigeration unit has no suction and exhaust valves, pistons, piston rings, cylinder liners and other fragile parts, which is convenient for maintenance and repair. Smooth and reliable operation, easy to realize long-distance operation and automation.
(2) High speed and good economic performance.
Screw compressors are rotary machines. Because there are no suction and exhaust valves, the speed can be increased. Usually the speed is 1500-3000 / min, which is generally higher than the speed of piston compressors, thus improving the economic indicators.
(3) Small size and light weight.
Due to the high speed, when the exhaust volume is the same, the machine is small in size, compact in structure, light in weight, low in metal consumption, and small in area.
(4) The foundation is small.
Since the screw compressor refrigeration unit does not have the mass inertia force of the piston compressor and the dynamic balance performance is good, the foundation can be made small.
(5) Strong adaptability to operation.
Can be applied to a variety of refrigerants, high volume efficiency. Good performance even at low evaporation temperatures and high compression ratios. Because there is no clearance volume, the volumetric efficiency is much higher than the piston type.
(6) The exhaust temperature is low.
With oil injection cooling, the exhaust temperature is lower than the reciprocating type, so single-stage compression can still be used at higher compression ratios. When the evaporation temperature is -40 ° C, the discharge temperature is less than or equal to 90 ° C, which is beneficial to the operation of the machine.
(7) Continuous stepless adjustment.
Since the most widely used current is the use of slide valves for energy adjustment, the refrigeration capacity can be adjusted steplessly within the energy range of 10% to 100%, achieving continuous stepless adjustment.
(8) There is no danger of liquid strike.
Due to the structural characteristics, the screw compressor is not sensitive to the wet stroke. It can allow wet vapor or a small amount of liquid refrigerant to enter the body without the risk of liquid strike.
2. The main disadvantages
(1) Rotor processing is difficult.
The rotor requires high machining accuracy and is difficult to process, requiring special equipment.
(2) The auxiliary equipment is huge.
For screw compressor refrigeration unit, in order to separate the lubricating oil in the exhaust gas, an oil separator and an oil return device with large volume, complicated structure and high efficiency are required.
(3) The noise is large.
Because the rotor cogging passes through the suction and exhaust orifices at high speed periodically, and leaks through the gap, the noise is relatively large. Generally, if all screw-type refrigeration compression is set in the machine room, the machine room should not be close to the main warehouse or other workshops. It is better to leave it separately from other buildings.
Tag: Modular Cold Room Cold Storage ; Cold Storage Air Cooled Condenser ; Turn-key Cold Storage Solutions ; Cooling Tube Fin Cold Room