May 31, 2017

Rare earths and wind turbines: Yes, it’s a problem

Despite wind industry lobbyists and apologists asserting otherwise, rare earth metals, particularly neodymium, are indeed extensively used in wind turbine magnets.

‘Permanent magnet machines feature higher efficiencies than machines with excitation windings (absence of field winding losses), less weight and the advantage of having no slip-rings and brushes. Machines above kilowatt range (and most below) employ high-specific energy density PM material, preferably of neodymium-iron-boron (Nd-Fe-B).’ —Wind Energy Systems for Electric Power Generation, by Manfred Stiebler, Springer, 2008

‘The data suggest that, with the possible exception of rare-earth elements, there should not be a shortage of the principal materials required for electricity generation from wind energy. ... Sintered ceramic magnets and rare-earth magnets are the two types of permanent magnets used in wind turbines. Sintered ceramic magnets, comprising iron oxide (ferrite) and barium or strontium carbonate, have a lower cost but generate a lower energy product than do rare-earth permanent magnets comprising neodymium, iron, and boron (Nd-Fe-B). The energy-conversion efficiency of sintered Nd-Fe-B is roughly 10 times that of sintered ferrite ... As global requirements for rare-earth elements continue to grow, any sustained increase in demand for neodymium oxide from the wind resource sector would have to be met by increased supply through expansion of existing production or the development of new mines. ... An assessment of available data suggests that wind turbines that use rare earth permanent magnets comprising neodymium, iron, and boron require about 216 kg [476 lb] of neodymium per megawatt of capacity, or about 251 kg [553 lb] of neodymium oxide (Nd₂O₃) per megawatt of capacity.’ —Wind Energy in the United States and Materials Required for the Land-Based Wind Turbine Industry From 2010 Through 2030, by U.S. Geological Survey, U.S. Department of the Interior, Scientific Investigations Report 2011–5036

‘Five rare earth elements (REEs)—dysprosium, terbium, europium, neodymium and yttrium—were found to be critical in the short term (present–2015). These five REEs are used in magnets for wind turbines and electric vehicles or phosphors in energy-efficient lighting. ... Permanent magnets (PMs) containing neodymium and dysprosium are used in wind turbine generators and electric vehicle (EV) motors. These REEs have highly valued magnetic and thermal properties. Manufacturers of both technologies are currently making decisions on future system design, trading off the performance benefits of neodymium and dysprosium against vulnerability to potential supply shortages. For example, wind turbine manufacturers are deciding among gear-driven, hybrid and direct-drive systems, with varying levels of rare earth content. ... Neodymium-iron-boron rare earth PMs are used in wind turbines and traction (i.e., propulsion) motors for EVs. ... the use of rare earth PMs in these applications is growing due to the significant performance benefits PMs provide ... Larger turbines are more likely to use rare earth PMs, which can dramatically reduce the size and weight of the generator compared to non-PM designs such as induction or synchronous generators. ... Despite their advantages, slow-speed turbines require larger PMs for a given power rating, translating into greater rare earth content. Arnold Magnetics estimates that direct-drive turbines require 600 kg [1,323 lb] of PM material per megawatt, which translates to several hundred kilograms of rare earth content per megawatt.’ — Critical Materials Strategy, by U.S. Department of Energy, December 2011

‘In the broader literature ..., concerns have been raised about future shortage of supply of neodymium, a metal belonging to the group of rare-earth elements that is increasingly employed in permanent magnets in wind turbine generators.’ —Assessing the life cycle environmental impacts of wind power: a review of present knowledge and research needs, by Anders Arvesen and Edgar G. Hertwich, 2012, Renewable and Sustainable Energy Reviews 16(8): 5994-6006.

‘A single 3MW [direct-drive] wind turbine needs ... 2 tons of rare earth elements.’ —Northwest Mining Association

Also see:

And:

May 28, 2017

Brief summary of CBD (cannabidiol) effects

Endocannabinoids are naturally produced in the body. The endocannaboid system operates through the nervous system with roles in several regulatory, physiological, and metabolic processes. They are produced in response to calcium levels in the cells to help stabilize nerve transmissions. The main endocannabinoids are called anandamide (N-arachidonoylethanolamine, AEA) and 2-arachidonyl glycerol (2-AG). The endocannabinoids act as activators (“agonists”) of the cannabinoid receptors which are also naturally present in the body.

There are two types of cannabinoid receptors:
CB1R is most prominent centrally as well as in the gastrointestinal tract. It modulates several inhibitory and excitatory neurotransmitters, and its activation inhibits the anxiety response. AEA is a partial agonist and 2-AG a full agonist of CB1R.
CB2R is most prominent peripherally with roles in the immune and hematopoietic systems, and its activation causes an inflammatory response. AEA is a weak agonist and 2-AG a full agonist of CB2R.

Cannabidiol (CBD) is the main phytocannabinoid in Cannabis besides tetrahydrocannabinol (THC, the intoxicating cannabinoid, which mimics AEA but at higher concentrations can increase anxiety; CBD can reduce the side-effects of THC). In “hemp”, which has negligible THC, CBD is the main cannabinoid.

CBD has strong analgesic and anti-inflammatory properties. Its half-life is ~9 hours. Unlike THC, it works mostly by preventing the breakdown of the endocannabinoids AEA and 2-AG, which serves to reduce anxiety and depression, respectively. Instead of activating the endocannabinoid receptors, it binds with the proteins that carry AEA and 2-AG to the enzymes that break them down.

CBD has other actions and consequent effects as well:

  • CBD binds with CB2R as an inverse agonist (deactivator), reducing inflammatory response.
  • CBD binds with 5-hydroxytryptamine (5-HT, serotonin) 1A receptor, reducing depression.
  • CBD binds with transient receptor potential cation channel subfamily V member 1 (TrpV1, vanilloid receptor 1, capsaicin receptor) as an antagonist (blocker), reducing pain response.
  • CBD binds with peroxisome proliferator–activated receptor (PPAR) gamma, reducing inflammation.
  • CBD has direct antioxidant effects.

In addition, the terpenes in Cannabis have anti-inflammatory and analgesic properties.

Cannabidiol in Pubmed-indexed science publications

April 24, 2017

Recent notes on the Irish language

(in reply to a question of why Irish spelling is so weird)

One reason for some of the quirks is the (generally) precise indication of consonants being broad or slender. This is reflected in pronunciation most obviously for d, t, and s. Broad d is like a hard [TH], slender d like [j]. Broad t is like a soft [th], slender t like [ch]. Broad s is [s], and slender s is [sh]. Spelling rules require that when consonants are broad they are flanked by broad vowels (a, o, u) and when slender by slender vowels (e, i). So there are often vowels that are there not for their own pronunciation but to indicate that the consonant has broad or slender pronunciation.

Many of the double-vowel and triple-vowel combinations (as in the name Saoirse [Seershuh or Sairshuh]) likely evolved out of the above rule.

Then there’s the softening (or aspiration or lenition) of consonants, which is indicated by an h after the consonant. (In traditional Irish, it is indicated by a dot over the consonant.) Some softened consonants are pronounced differently when they are at the start, middle, or end of a word. And if they are broad or slender. Often the lenition makes them silent.

Besides causing lenition, various declensions cause eclipsis of a consonant at the start of a word, a voicing or nasalization indicated by an eclipsing consonant in front, so that the original consonant after it is essentially silent. Examples are mb, gc, nd, ng, bhf, bp, dt. In words starting with a vowel, an h (sometimes hyphenated) is added before, but does not “eclipse”, the vowel.

Some declensions also cause an h or t to be added to the start of the word. If the word starts with an s, the added t eclipses it (eg, the street: an tsráid [un trawd].

Those are some of the reasons there often seems to be too many letters, even though there only 18 in the traditional alphabet.

PS: In 1948, Irish spelling was standardized and greatly simplified!

--------------------

(in reply to a shared article by Barry Evans, on distinct “do” (particularly in the past tense, e.g., “I do not think ...”) and “-ing” forms betraying a Celtic influence in the formation of English)

Irish (these are all literally present-tense forms):
Scríobhim - I write
Tá mé ag scríobh - I am writing [at this moment]
Bím ag scríobh - I am (‘I do be’) writing [these days] (present habitual tense of “be”)
Tá mé tar éis scríobh - I was just (‘I am after’) writing
Tá mé scríofa - I have written [in the past]
Tá leabhar scríofa agam - I have written a book
Tá an leabhar ar scríobh - The book has been written
Also of interest is the past habitual tense compared with the conditional mode:
Scríobhainn - I would (‘I used to’) write [in those days]
Bhínn ag scríobh - I would (‘I used to’) be writing [in those days]
Scríobhfainn - I would write [if I could]
Bheinn ag scríobh - I would be writing [if I could]
Note: “scríobh” is a verbal noun (gerund) and “scríofa” is a verbal adjective.

March 23, 2017

Letter in support of proposed wind turbine sound rules

To the Clerk of the Vermont Public Service Board:

I support the proposed wind turbine sound rules as a first step to protect the aural environment of our mountains.

As you know, a quiet rural night in Vermont is likely to have a sound level of only 25 dBA or even less. An increase in ambient noise of 5 dB is recognized as a cause of widespread complaints. So limiting the sound level at night to 35 dBA is not severe but actually rather lenient.

The proposed rule does not address low-frequency noise, which Denmark (the world's leader in wind energy technology and implementation) since 2011 has limited to 20 dBA indoors (10-160 Hz).

Infrasound (which is not heard but instead felt) is also a concern, with many acoustic engineers determining that a C-weighted indoor limit of 50 dB is necessary to protect health.

Nor does the proposed rule address amplitude modulation, the distinct "swish" or "thump" of large wind turbines. In the UK, planning permission for the Den Brook project included a rule to limit amplitude modulation: A 125-ms pulse of 3 dBA or greater (3 dB being the difference in noise level detectable by the human ear) can not occur in any 2-second period five or more times in six or more minutes of any hour, when those minute-long average noise levels are 28 dBA or more.

While these limits, as well as the proposed setback of 10 times the total height from residences (which should be at least 15 times the height, and from property lines, so that people can enjoy all of their property), begin to protect human neighbors, they do nothing to protect the wildlife of the mountains, who in most cases are much more sensitive to sound than humans.

[See also:  Proposal and comments for implementing a rule regarding sound from wind generation projects, by Stephen Ambrose]

March 20, 2017

Devils take you.

Irish curse:  Go mbeire an dhá dhiabhal dhéag leo thú.

Pronunciation:  Guh mairuh un gaw yeewul yayug luh hoo.

Translation:  May the twelve devils take you with them.

Actual word order:  That carry the two devils ten with them you.

March 15, 2017

Jet lag, depression, and the circadian rhythm

From “The Sleeping Cure”, by Richard A. Friedman, New York Times, March 12, 2017:

When you quickly cross several time zones, your circadian rhythm remains stuck in the city you left behind. Arriving in Rome with your New York City brain is what produces the unpleasant symptoms of jet lag: fatigue, malaise, poor concentration and mood changes.

When you leave New York at 6 p.m., the Italians are probably in bed asleep. But you won’t feel ready for sleep until around 11 [p.m. New York time, or around 5 a.m. in Rome]. To make the right adjustment, you need to shift your internal clock earlier by six hours.

Unfortunately, exposure to light in the middle of the night will do the opposite. Instead of shifting you earlier to Italian time, it makes you feel it’s even later — that the night is over and it’s already morning.

If you’re ever in that situation, close the shades and put on dark sunglasses. Keep the glasses on until lunchtime in Rome — or 7 a.m. back home. Then go out into the sun, have an espresso and enjoy the splendor of the ancient city. This will shift your clock closer to Roman time.

The clock in your brain doesn’t just take cues from light, but from the hormone melatonin as well. Every night, about two to three hours before you conk out, your brain starts to secrete melatonin in response to darkness. Taking a melatonin supplement in the evening will advance your internal clock and make it possible to fall asleep earlier; taking it in the morning will do the opposite. (You might assume this would make you even more tired during the day but it won’t; you could think of it as tricking your brain into believing you slept longer.)

So now you know the fix for jet lag: Travel east and you’ll need morning light and evening melatonin; go west and you’ll need evening light and morning melatonin.

...

Researchers have developed a limited form of sleep deprivation that is euphemistically called wake therapy. It has been shown to have sustained antidepressant benefit in patients with bipolar disorder and major depression. The idea is to get up for the day halfway through the usual sleep period, which shifts the circadian clock to an earlier time. It’s thought that this works by realigning the sleep cycle with other circadian rhythms, like changes in levels of body temperature and the stress hormone cortisol, that are also out of sync with each other in depression.

Studies show that it is possible to make wake therapy even more powerful by incorporating two additional interventions: early morning light therapy and what’s called sleep phase advance, in which the patient goes to bed about five to six hours earlier than usual and sleeps for about seven hours. This combination of treatments is called triple chronotherapy, and the typical course involves one night of complete sleep deprivation followed by three nights of phase-advanced sleep and early morning light.

February 26, 2017

Climacteric, a poem

CLIMACTERIC
by Eric Rosenbloom
copyright 2017

Not the self-consuming fire
In glorious explosion
Leaving the quiet worm
To slowly grow a new self
In the sudden ashes of the old —

Our turnings are slow ones
The growing frailty of parents
And their dying
The growing independence of children
And their leaving
The dogs and cats that grew with them
Their lives now ending
Griefs accruing ...

The slow ending of an age
And the aged required to start anew ...

The fire is in the worm
Nurturing, destroying in turn
The ashes accumulate
Overwhelming
Until we shake them off
And turn to face the new day —
The phoenix of our yesterdays
In the phoenix of our tomorrows —
Burning, burning