Here’s a vivid science experiment that demonstrates the benefit of wearing a mask to reduce contagion. Although these petri dishes are not COVID-19 but rather random bacteria, they demonstrate the dispersion of droplets by speaking, shouting, and singing with and without masks. They experimenters also demonstrate the remarkable reduction in droplets as social distance is increased.

A dear friend asked for instructions on how I cook Salmon so that it stays flavorful and moist. It’s fairly simple: I brown it and finish it with steam.

Preparation

Slice the salmon fillet into serving size pieces about 1.5 inches wide. Arrange the pieces skin-side down on a plate. Salt and then spread soft butter on the top (pink) side.

Cooking

Select a skillet with a lid that’s large enough for all the salmon. Pre-heat it until water beads and dances when splashed on the dry surface (about 375 degrees). Apply a light coating of olive oil, and quickly place all the pieces in the skillet, buttered side down, skin up. Sear for 95 seconds uncovered, then turn skin-side down. The pink side will be pleasingly brown thanks to the butter. Reduce the heat a bit (300) and sear the skin side for another 90 seconds.

Holding the lid at the ready splash in some dry sherry (1 to 2 oz) and clamp the lid on trapping the steam as the liquid flashes to vapor. Reduce the heat but keep the liquid boiling (275), and steam for 3 minutes. Remove from the heat and leave covered until you serve it. The liquid remaining in the pan may be spooned over the salmon when you plate it.

This same method would well for steaks and hamburgers. Pre-season the meat with salt, butter, and mustard before searing.

For most people, making zoom work is merely clicking the link in an invitation to a meeting. The rest happens automatically, all you do is follow the prompts. Easy?

Not always. Particularly for those who infrequently use the internet. The symbols, gestures, and words that are required to interpret and interact with a computer constitute a foreign language that’s not familiar. The glossary below demonstrates my point.

There are many more of these terms, and many of them refer to an action originally performed with a mouse, but now refer to gestures performed on a touch-sensitive surface with the finger(s). We stroke and tap, not point and click.

It’s not realistic to think that people will take a course to learn how to use their computer or tablet to access Zoom. Coaches or guides are needed to help them acquire minimal familiarity and skills to get started.

Here are some useful links to use when installing Zoom.

(Optional) Sign Up for a personal Zoom Account so you can start meetings and not just join meetings started by others. [https://zoom.us/signup]

Download the Zoom Installer (any laptop or tower computer) [https://zoom.us/client/latest/ZoomInstaller.exe]

Test the Zoom connection and installation. [https://zoom.us/test]

Here is the abstract of a new study. It concludes that COVID-19 is much more contagious than we believed.

High Contagiousness and Rapid Spread of Severe Acute Respiratory Syndrome Coronavirus 2

Severe acute respiratory syndrome coronavirus 2 is the causative agent of the 2019 novel coronavirus disease pandemic. Initial estimates of the early …

“This is the first major medical voice to express this opinion.  Dr. Shapiro is not just expressing a personal opinion, but that of the largest academic medical system in the country…over 40 hospitals (3 in Italy), 36 senior living facilities, #5 in NIH funded research, and 3.8 million insured lives in its health plans.  We have a lot of data.

Only 5 minutes.  https://wdrv.it/06fe241fb

He is careful not to claim this applies to already heavily infected areas on the east coast.” — Mark Laskow, Key West

It’s often hard to find suitable places to tie a temporary indoor banner. An “X” pole will keep it taught and allow it to be leaned against a wall or chairs. Poles made of 3/4″ PVC pipe are easily fabricated and may be joined by short scraps of 1″ PVC pipe as shown elsewhere on this site (see below).

Here’s a sketch:

Hooks made from coat hanger wire insert into the open ends of the pole and secure the top corners of the banner. The weight of the banner tends to splay the “X”, drawing the top edge of the banner tight. Further tensioning can be accomplished by securing the lower corners of the banner with bungee cords. This whole assembly may be leaned against a wall or lashed to chairs with additional bungee cords.

Here’s the article on pole fabrication:

Ever since I moved to the retirement community where I have lived since 2013 I’ve been struggling with the bad acoustics of our meeting hall. There is so much reverberaton that the sound from our PA system gets muffled and is prone to annoying feedback.

We are seniors, many with hearing loss. The staff does not include a crew of AV engineers to keep things tweaked up, and few residents are versed in how to use a microphone properly. So it’s not surprising that many meetings and performances were marred by bad sound.

Today audio engineers have hi-tech solutions to these problems: a digital toolbox of enhancements for the sound that compensates for the problems just mentioned. They have technical names like “equalizer”, “compressor”, “notch filter”, and “limiter.” They allow a public address (PA) to become a sound system tailored to the acoustics of the room. The categorical name for this technology is “Digital Signal Processors” or DSP.

A professional sound system for a medium-size theater can cost in the mid-five figures. We hired an acoustics expert to make a recommendation. He brought instruments and went about the hall firing a starter’s pistol and making other loud noises and in due course told us that acoustic wall treatments and such would not be much help, but that we should consider an advanced audio system featuring DSP for each of the speakers in the room. This would allow each speaker to be custom adjusted for each of the several different arrangements of chairs and performance areas.

These engineering adjustments would be saved in the audio console as presets so that house staff could simply select the preset that corresponds to the room layout for any given event. If successful, the result would be loud clear sound that was below the threshold of feedback.

We already had a DSP device capable of presets. It had been purchased and installed around the year 2000 and was a cutting-edge device with a price to match – about $1,200. The Sabine Graphi-Q converts the sound from an audio mixer to a digital stream, splits it into 31 one-octave “bands”, each of which has its own volume control. In addition is has 12 filters that can trap and tune out a squeal from feedback. But the processing doesn’t stop there, next it detects peaks of loudness in the stream and tamps them down (compression) essentially normalizing the loudest blasts. This has the effect of making the average audio less loud, the stream is amplified (gain) back to the original average level. And just in case the compression isn’t enough to prevent a super loud blast, there is another filter that imposes a loudness ceiling (limit).

All of this processing of the stream happens in less than two-thousandths of a second so it’s imperceptible to the listener. But if a room has more than one speaker, the transit time for sound is perceptible. Sound travels about 1,100 feed a second. If you are 50 feet from the source, the sound reaches you with a delay of about 50 thousandths of a second. When the sound from a second speaker close to the listener combines with the delayed sound, the interference between the sounds can make it fuzzy. That aggravates hearing loss issues. To fix this, the Graphi-Q has an adjustable delay setting that is set for the distance that the loudspeaker it controls is from the stage.

The delay is the last link in the chain of processes accomplished by the Graphi-Q processor. Installing and adjusting these devices is a lab course in digital signal processing techniques. It allows a novice technician to experience hands-on what he has learned about in textbooks.

The Graphi-Q is obsolete. On eBay you will find them offered for between $60 and $200, though Guitar City has one listed at the original $1,200 price. Sabine, the manufacturer, has closed its doors. But the company website has been preserved and archived (link below). That site is a gem of useful information because it includes whitepapers on signal processing techniques, acoustics, and the manuals and software for the Graphi-Q. This means that for about $100 you can buy a full featured laboratory to learn about DSP. It’s the lab course for Audio Engineering 101.

Links:

https://web.archive.org/web/20130522194002/http://www.sabine.com/Pro_GRQ2_index.htm

https://www.prosoundnetwork.com/archives/sabine-graphi-q-3102-digital-eq