"Our results indicate that on the William & Mary campus, ultrasound noise exists between 20 to 55 kHz and at an intensity between 13 to 78 dB SPL. In addition, we identified motion sensors as the primary source of ultrasound noise. Based on student use of surveyed campus spaces, we concluded that William & Mary students are chronically exposed to ultrasound noise pollution and are potentially suffering from the symptoms associated with industrial ultrasound exposure. The prevalence of motion sensors in public spaces outside the William & Mary campus suggests that ultrasound noise pollution may be ubiquitous."
Just because we can't hear them we can't deny ultrasounds exist and accompany almost every sound.
"There's no single culprit for ultrasonic waves, Leighton said. A number of machines make them totally unintentionally. Some loudspeakers play them during test cycles. And Leighton said he's found manufacturers of those sorts of devices that are interested in his research and fixing their ultrasonic problems. Other industries, though, like the makers of devices designed to keep away pests from yards and basements, are more resistant."
And BTW, this event occured after i started to complain about refrigerator's pollution with ultrasound. Can't find it now, was most likely on g+ and now it's gone.
"The most famous supposedly ultrasonic event occurred when American diplomats in Cuba suffered a strange constellation of symptoms that officials initially attributed to some sort of ultrasonic weapon. And although the claim hasn't held up under scrutiny, that was perhaps not entirely nutty; the most severe symptoms of ultrasonic-wave exposure do include headaches, tinnitus and hearing loss similar to what the U.S. diplomats encountered in Cuba. (Leighton, like most scientists, is skeptical that ultrasonic weapons were actually involved in that event.)"
Why would only the plastic wheel of a refrigerator next to the expansion valve become brittle and brake?
Ultrasound can do a number of things, including cleaning. There are firms that clean the dust from your blinds with ultrasound. Others can unclog pipes. When i worked at AVX Vancouver we had an broken ultrasound cleaning machines for the sorting plates (that i tried to fix). But you had to add some abrasive dust in the water so the ultrasound will agitate it and rub it against the surface to clean it.
There are also reports that medical ultrasound devices can cause long term damage:
"Recent studies have reported the use of ultrasound-assisted lipoplasty on the breast4 and the extraction of high volumes of fat. Emphasis should be placed on the long-term effects of ultrasound-assisted lipoplasty on young patients when sensitive areas such as the head, neck, and breast are treated and when high-intensity ultrasound energy is applied in close proximity to major blood vessels and nerves."
Many DIYers know what an expansion valve is. Is a device that allows the controlled turning of the freon from liquid to gas inside the coils of a refrigerator. You can't possibly have missed the hissing sound, among many other sounds of the refrigerator. Especially the old ones with not so many fans. There is a continous high frequency sound that is on for as long the compressor works. That is the sound of the freon passing from the narrow passage of the expansion valve.
But first let's bring some numbers from a... Russian engineer in refrigeration (the first site i found the information after hours of searching, have to use history of my browser to find it, i first did a lot of reading before i started this blog post).
"In general, to ensure the return of oil from the circuit to the compressor crankcase and acceptable pressure losses, the flow rate in the gas main should be at least 4 meters per second for horizontal sections and at least 6 meters per second for upstream sections. To avoid unacceptably high noise levels, the maximum allowable gas flow rate is limited to 15 meters per second."
I know this is intuitive only but how much faster do you thing the gas passes through the orifice of the valve if the speed on the line is 8 m/s ? Could it go near the speed of sound, which usually is the speed of which a gas passes through an orifice from a high pressure to a low pressure chamber?
Couldn't find anywhere data on ultrasound refrigerator pollution but i know the one in our apartment has a cardboard, not plastic cover in the rear and if i take that one out i start to feel uncomfortable and the plastic wheel of the fridge in that corner broke.
What i wrote above is bad enough by itself. Now imagine you go on the beach and come back and bring some sand in your shoes. My only shoes have been designed like a sand magnet. Sketchers with some sort of fabric/mesh on top. Nobody would believe me that i can never find acceptable shoes if i go in stores.
And here's the other thing. I wrote about many times before. The Tualatin Refuge. It's the ex-site of a farm or two farms, dairy and pigs, not sure. Sherwood developed enough for things to go ugly with the farms. So they shut them down and turned them into a Wildlife Refuge. It's been almost three decades since they shut those farms and during hot summer days it still stinks like a pig pool in there. Especially after they went into the final phase of restoration, built an artificial wet land and eradicated the lavender that was planted there temporarily. But soon after i started to go out and walk, around 2012 i think (after i wrote the first time in a blog post about the possibility of identical match between two singers of Romania and two of US) they came and poured new gravel on the 4 miles of trails. I complained about this many times before. Some sort of basaltic gravel made mostly of quartz (SiO2 or glass) with other minerals. However they allowed their own heavy SUVs to go on the trails and those broke the gravel and turned it partially to a fine, abrasive, dust. That i carry on my shoes and bring it home. That is risen from shoes and shaken by the ultrasound component of the hissing expansion valve with pour sound insulation (like the abrasive dust inside an ultrasound cleaning machine). Which i inhale, then it gets eliminated from lungs into esophagus and irritates it to the point it becomes painful and infected, in synergy with my wrongfully designed partial dentures.
After i moved in Tualatin and started to walk in this park they brought in the same type of gravel, only finer and poured it on perfect trails, exactly like at the Refuge and now i remembered, at Tryon around the same time like at the Refuge.
That infection inflames the nearby lymph nodes that press on the pancreatic and liver ducts, making it difficult for pancreatic and liver secretions to be emptied in the duodenum.
On top of that, there is also an ultrasound component of the squeak coming from joints between the floor and the studs on the ceiling. Which squeak is tightly correlated with my activities (if i use the computer, which sites i open, which news i see, what i write). The on-demand supplement.
I believe no other then me has been most at the refuge. Because i go there several times a week and never see the same people twice.
Same goes for room AC, though stronger. However. Water condensates on the cool fins of the AC and that water catches some of the dust.
None of these would happen if we didn't have these giants mestubushi in our homes. But for me, they created the perfect storm. Dusty gravel, shoes, redwood, partials. BTW, did i say the partials have been built in a Japanese lab?
