Tag Archives: coatings

Health

Here’s Which Coatings You Really Need on a New Pair of Glasses

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Photo: Ground Picture (Shutterstock)

Buying eyeglasses can feel weirdly similar to buying a new car: Prices are often hidden from you, they cost more than they have any right to—and there are a whole bunch of mysterious upgrades pushed at you. Coatings. I’m talking about coatings: the anti-scratch, anti-glare stuff you can add to your lenses to make your glasses—and your vision—ever more powerful. On the surface, these sound like good sense. (As a man who once cleaned his glasses with a concrete-splatter shirt-tail that acted like sandpaper, anti-scratch coatings sound like a good idea.) But do these coatings actually work, and do you really need any of them?

Scratch-resistant coatings 

This is simply a clear coat applied to the front and back of your lenses that helps protect them from scratches and scuffs as you fumble your way through your friction-filled life. Almost all modern lenses are pretty scratch-resistant in their basic form, but the word “resistant” does not mean “impervious,” so adding a little extra protection is always a good idea. If you’re given the option of adding extra scratch resistance, it’s usually worth it because it extends the useful life of your eyewear.

Recommendation: Hard yes.

Anti-reflective coatings

This coating reduces the amount of light reflected off of your lenses. This can help improve the clarity of what you’re looking at—especially computer screens, which shoot light at your eyes—and help with night vision, especially when you’re driving. Contrary to what you might have heard, they actually won’t do much about light glare, like when someone highbeams you on the highway. Not everyone needs AR coatings, however—if you don’t do much night driving and don’t work in front of a screen much, you might never notice a need for this.

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2 for $60

Crocs: 2 for $60

Step in style
Included in this sale are some very on-trend marble and tie-dye varieties, from black and white to sorbet pastels. Text your mom: she’s gonna want a pair.

Recommendation: Depends on your lifestyle.

Ultraviolet coatings

Ultraviolet (UV) light is the violence the sun beams down at us every day—it’s the same light ray that blesses us with sunburn and, eventually, skin cancer. So as you might imagine it’s not super good for your eyes, either, which is why most sunglasses will advertise a certain amount of UV protection. Keep in mind, though, that your standard un-coated eyeglass lens blocks most UV rays already—the coating just boosts that to 100% protection.

Recommendation: Not a bad idea, but only essential if you spend a lot of time in the sun.

Anti-fog coatings

This coating aims to reduce or eliminate that death-defying moment when you step out into the cold weather and your glasses immediately turn opaque with water vapor, or when you put on that facemask and your own exhalation turns against you. You can get a coating on your lenses that will fight off fogging, but it’s not always available if you have a complex prescription or other coatings on the lens—and it will only last about 1-2 years. You might be better off just using one of the many wipes, sprays, and gels available to prevent fogging, or simply dealing with the occasional inconvenience.

Recommendation: Probably skip.

Blue-light blockers

All the screens we look at all day long are beaming “blue light” at us, a frequency of visible light that’s been shown to have a negative impact on our overall health. So getting a coating that filters this blue light out might sound like a good idea. But there’s actually zero evidence that a blue-light coating does you any good—most of the issues we experience with our eyes after a long day of staring at screens have nothing to do with blue light. This coating won’t do you any harm, but it probably won’t do you any good.

Recommendation: Pass.

There are other coatings you can get, like a mirrored coating that will tint your lenses, keeping them opaque so people can’t see your eyes (but don’t block any light coming into your eyes the ways sunglasses do) or transition coatings that darken lenses in response to light, transforming your glasses into sunglasses. These coatings are just personal choice—if you want cool colored lenses or hate having separate sunglasses to switch back and forth, go for it.

In the end, you don’t need any of these coatings—your glasses will do their job just as well without them—and the only coating that’s a good choice for everyone is the anti-scratch coating. For the rest, consider how you live and how you use your glasses before shelling out for them.

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Business

Stock Futures Rise After Nasdaq Enters Correction

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U.S. stock futures gained, putting indexes on course to pare some of the sharp losses that have come as investors reposition their portfolios, spooked by the prospect of tightening monetary policy and slowing growth.

Nasdaq-100 futures rose 0.9% Thursday, a day after a late tech selloff dragged down indexes. Futures tied to the S&P 500 rose 0.5% and blue-chip Dow Jones Industrial Average futures added 0.4%. 

In premarket trading, Travelers Companies rose over 4% after reporting record net income in the fourth quarter.

American Airlines

Group gained 1.6% after saying it had trimmed its losses.

Netflix

will be one of the first tech giants to post its fourth-quarter results, after markets close, when

PPG Industries

will also report.

The technology-heavy Nasdaq Composite shed 1.1% on Wednesday.



Photo:

BRENDAN MCDERMID/REUTERS

Hong Kong-listed Chinese stocks jumped after an interest-rate cut by China’s central bank lifted shares of property developers and tech giants. The Hang Seng Index rose 3.4%, while mainland China’s Shanghai Composite Index edged down 0.1%. Elsewhere in Asia, the Nikkei 225 rose 1.1%. The pan-continental Stoxx Europe 600 edged up 0.1%. 

Faced with the prospect of multiple interest-rate rises, cooling growth and inflation at multidecade highs, investors have been reassessing the pandemic-era playbook that focused on outsize gains for growth stocks, such as tech. In recent sessions, investors have rotated into sectors expected to perform better in the coming year, such as financials and energy. 

“I don’t see a whole lot in the market that is really alarming me. There is no one out there saying ‘run for the hills,’ but there are those saying they are going to take off risk and reposition to other areas of the market,” said

Kara Murphy,

chief investment officer of Kestra Holdings.

That has prompted tumultuous trading. On Wednesday, the Nasdaq Composite closed more than 10% below its all-time closing high, putting it in correction territory.

Investors are selling government bonds in anticipation of higher interest rates, pushing up yields, and in the process, pressuring tech companies, whose future earnings become less attractive when compared with bonds with rising yields.

The yield on the 10-year U.S. Treasury note crept down to 1.823% Thursday from 1.826% Wednesday, after rising steadily in recent weeks. Benchmark German bund yields fell further into negative territory, a day after they briefly turned positive. The yield on the 10-year German government bond fell to minus 0.037% Thursday from minus 0.014% Wednesday.

U.S. home prices hit an all-time high in 2021, but those increases are expected to slow in 2022 thanks to a number of economic factors. Here’s what’s driving the housing market and what that could mean for prospective buyers and sellers. Photo: George Frey/Bloomberg News

Investors are awaiting data on the U.S. housing market, a bright spot for the economy. The data, due at 10 a.m. ET, is expected to show that existing home sales slowed in December, but were still on track for the best year since 2006. 

Brent crude, the international oil benchmark, fell 0.5% to $88.01 a barrel. This follows a rally partly driven by the potential for supply disruptions in Russia and the Middle East. On Wednesday, Brent crude futures hit their highest level since October 2014.

Write to Will Horner at william.horner@wsj.com

Copyright ©2022 Dow Jones & Company, Inc. All Rights Reserved. 87990cbe856818d5eddac44c7b1cdeb8

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Business

Stock Market Today: Dow Rose as Moderna Slumped Again

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The


Dow Jones Industrial Average
had one of its best days this year on Monday, as value and defensive stocks led a rebound from last week’s market declines.

The news Monday was relatively positive, with signs that the Omicron variant of Covid-19 might be less severe than earlier strains and reports that China is considering easing monetary policy. On the Federal Reserve policy front, the latest reporting suggested that the central bank could announce plans at its next meeting to more quickly pull back from its bond-buying program.

The Dow surged 647 points, or 1.9%, for its best one-day point gain since November 2020 and the largest percentage increase since last March. The


S&P 500
closed up 1.2% and the Nasdaq Composite rose 0.9%, while the small-cap


Russell 2000
gained 2.1%, for its fourth-straight daily move of 2% or more.

Post-pandemic reopening stocks were among the biggest gainers on Monday. The


U.S. Global Jets
exchange-traded fund (ticker: JETS) added 5.3%, as


American Airlines Group

(AAL) added 7.9% and


United Airlines Holdings

(UAL) jumped 8.3%. Cruise lines


Carnival

(CCL) and


Royal Caribbean Cruises

(RCL) surged 8.0% and 8.3%, respectively.


Marriott International

(MAR) added 4.5%,


Live Nation Entertainment

(LYV) rose 6.1%, and


Cinemark Holdings

(CNK) gained 7.7%.

S&P 500 value stocks as a group gained 1.4% on Monday, versus a 0.9% rise for growth stocks in the index.

Investor attention remains focused on the newly discovered Omicron variant of coronavirus, news of which recently brought about the Dow’s worst day of the year and saw volatility rock markets last week. The latest headline driving sentiment comes from South Africa, where data—though from a small sample size—suggest that symptoms caused by Omicron were milder than with other variants.

Investors aren’t out of the woods yet, however. The broad market will remain sensitive to daily headlines about Omicron—both good and bad.

“It still feels like we’re in the guesswork stage of working out what the impact of Omicron will be,” said Russ Mould, an analyst at broker AJ Bell. “It would be naive to rule out further volatility as markets attempt to work out exactly what’s going on.”

On Monday, the news was positive and investors bought the market. All 11 S&P 500 sectors closed in the green.

Fed policy has been pushing investor sentiment the other way. Chair Jerome Powell indicated last week that the central bank would consider speeding up its slowing, or tapering, of monthly asset purchases, which add liquidity to markets, amid higher inflation.

“We’re really at a fascinating crossroads in markets at the moment,” said Jim Reid, a strategist at Deutsche Bank. “The market sentiment on the virus and the policy makers at the Fed are moving in opposite directions.”

Those trends mean different things for different kinds of stocks and indexes.

If Omicron is less severe than feared, then the economy might hold up better than expected. That would be good for economically-sensitive cyclical stocks, like many of those in the Dow. Higher bond yields and interest rates, however, can put downward pressure on stock valuations, particularly those with nosebleed price-to-earnings ratios, many of which are found in the Nasdaq.

“Like Friday, how the Nasdaq trades will likely determine the day, as markets want to see the tech sector stabilize after intense weakness late last week,” wrote the Sevens Report’s Tom Essaye. “If the Nasdaq can stabilize, the broad market can bounce.”

The tech-heavy index bounced from a loss of about 1% shortly after Monday’s opening bell.

In the commodity space, oil prices rose Monday after Saudi Arabia raised its January prices for Asian and U.S. customers over the weekend by $0.60, in a sign of firmer demand expectations.

Futures contracts for the international oil benchmark Brent rose 4.6%, to above $73 a barrel, with U.S. futures for West Texas Intermediate crude up 4.9% to about $69.50 a barrel.

“Given that OPEC+ is proceeding with its planned 400,000 barrels per day increase this month, it appears that Saudi Arabia is taking a punt that Omicron is a virus in a teacup,” said Jeffrey Halley, an analyst at broker Oanda. “Saudi Arabia’s confidence, along with the South African Omicron article over the weekend, is a boost to markets looking for good news in any corner they can find it.”

Cryptocurrency markets remained depressed after digital assets took a tumble over the weekend.


Bitcoin
and


Ether,
the two leading cryptos, remained off their lows following the stark fall Saturday, but were slipping after steadying Sunday. Bitcoin was trading hands around $49,000—down from more than $57,000 as recently as Friday—with Ether holding above $4,000.

Here are several stocks on the move Monday:


Nvidia

(ticker: NVDA) was among the most actively traded stocks in the U.S. Monday, closing down about 2.1%. Shares of fellow semiconductor firm Advanced Micro Devices (AMD) lost 3.4%.


Lucid Group

(LCID) stock dropped 5.1% after the electric-vehicle startup revealed that it had received a subpoena from the Securities and Exchange Commission, without offering many details.


Kohl’s

(KSS) gained 5.4% after an activist investor said it should explore selling itself.


Moderna

(MRNA) fell 13.5% after its president said that the risk that vaccines don’t work as well against Omicron is high. Pfizer (PFE) stock slid more than 5%.

Alibaba Group Holding (BABA) stock closed up 10.4% after a management shakeup at the e-commerce giant.


Deutsche Bank

(DB) rose 3.6% after JPMorgan upgraded the bank to Overweight from Neutral, adding that the group shows positive revenue developments in key divisions.

Pharma giant


Roche

(ROG.Switzerland) rose 1.5% in Zurich after announcing that it would release rapid antigen tests for Covid-19 and flu viruses next month.

Food delivery group


Just Eat Takeaway.com

(JET.U.K.) fell 4.9% in London following a price target cut and downgrade to Market Perform from Outperform by Bernstein, which sees few positive catalysts in the pipeline for the company.

Write to Jack Denton at jack.denton@dowjones.com

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Business

Stock Market Today: S&P 500, Nasdaq Dip After Apple and Amazon Woes

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Text size

Oil companies Chevron and Exxon Mobil will be in the earnings spotlight at the end of a busy week.


David McNew/Getty Images

The stock market retreated from earlier gains Friday after


Apple

and


Amazon.com

reported disappointing quarterly results. Plus, signs of caution about the economy weighed on stocks across the board.

In afternoon trading, the


Dow Jones Industrial Average
was flat, after the index climbed 239 points Thursday to close at 35,780. The


S&P 500
and the


Nasdaq Composite
were both down 0.1% Both the Nasdaq and the S&P 500 hit record highs at the close Thursday.

Despite the weak finish, October has been a strong month for stocks. The S&P 500 has gained 5.5% for the month of October, which saw the market rebound from an early autumn drawdown. In September, concerns about supply chain constraints and rising bond yields pushed stocks lower.

Several factors enabled stocks to rebound this month. Bond yields have paused in their larger ascent. Companies have mostly beat earnings estimates. And while risks still remain—yields aren’t necessarily finished rising and supply chain constraints aren’t easing much—retail investors bought the dip.

“They [retail investors] saw the 5% [market decline] and so when they see the opportunity to buy down 5% they step in and they do that,” said John Ham, wealth advisor at New England Investments & Retirement Group.  

Big Tech earnings put the issue of shortages on center stage on Friday.


Apple

(ticker: AAPL) stock fell 2.1% after the company reported a profit of $1.24 a share, in line with estimates, on sales of $83.4 billion, below expectations for $84.9 billion. The company said supply-chain constraints due to chip shortages were worse than expected. iPhone sales were $38.9 billion, below expectations for $41.5 billion. 


Amazon

(AMZN) stock dropped 2.9% after the company reported a profit of $6.12 a share, missing estimates of $8.92 a share, on sales of $110.8 billion, below expectations for $111.6 billion. The company said labor shortages, higher shipping costs, and other rising expenses are eating into profits. Management also guided for current quarter sales of $135 billion at the midpoint of its range, below analysts’ expectations for $142 billion. 

Even if Apple and Amazon stocks were having a better day, the stock market would still look fairly weak. Just over half of S&P 500 stocks were in the red, according to FactSet. 

This comes as the yield curve—the difference in yield between long-dated and short-term debt—declined. The 10-Year Treasury yield slipped to 1.56% from hitting 1.61% earlier. The 2-Year yield held at 0.5%, where it has mostly sat since Tuesday. Higher short-term rates indicate markets anticipate a Federal Reserve rate hike sooner rather than later, which could lower long-term economic demand and inflation. Some on Wall Street have recently flagged the falling yield curve as a potential risk to monitor.

In cryptocurrency markets, Ethereum—the leading crypto asset after Bitcoin—hit an all-time high above $4,400, according to data from CoinDesk.

Here are six stocks on the move Friday:


Chevron

(CVX) gained 0.9% after the company reported a profit of $2.96 a share, beating estimates of $2.21 a share, on sales of $44.7 billion, above expectations for $40.5 billion. 


Starbucks

(SBUX) stock dropped 7.4% after the company reported a profit of $1, beating estimates of 99 cents, on sales of $8.1 billion, below expectations for $8.2 billion. 


Newell Brands

(NWL) stock rose 5.1% after the company reported a profit of 54 cents a share, beating estimates of 50 cents a share, on sales of $2.79 billion, above expectations for $2.78 billion. 


Caterpillar

(CAT) stock rose 0.3% after getting upgraded to Buy from Neutral at UBS. 


Synchrony Financial

(SYF) stock rose 0.3% after getting upgraded to Buy from Neutral at Citigroup. 


U.S. Steel

(X) soared 12% following third-quarter earnings Thursday that smashed expectations and an announcement that the company would raise its dividend.

Write to Jacob Sonenshine at jacob.sonenshine@barrons.com

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Science

Extending our reach into the cosmos with new mirror coatings

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The LIGO coating materials to be tested are deposited on thin glass disks, much smaller than the LIGO mirrors. The pinkish color in the photo is due to the thin layer of metal oxide deposited on the surface. Credit: Caltech

Since the Laser Interferometer Gravitational-wave Observatory (LIGO)’s groundbreaking detection, in 2015, of gravitational waves produced by a pair of colliding black holes, the observatory, together with its European partner facility Virgo, has detected dozens of similar cosmic rumblings that send ripples through space and time.

In the future, as more and more upgrades are made to the National Science Foundation-funded LIGO observatories—one in Hanford, Washington, and the other in Livingston, Louisiana—the facilities are expected to detect increasingly large numbers of these extreme cosmic events. These observations will help solve fundamental mysteries about our universe, such as how black holes form and how the ingredients of our universe are manufactured.

One important factor in increasing the sensitivity of the observatories involves the coatings on the glass mirrors that lie at the heart of the instruments. Each 40-kilogram (88-pound) mirror (there are four in each detector at the two LIGO observatories) is coated with reflective materials that essentially turn the glass into mirrors. The mirrors reflect laser beams that are sensitive to passing gravitational waves.

Generally, the more reflective the mirrors, the more sensitive the instrument, but there is a catch: The coatings that make the mirrors reflective also can lead to background noise in the instrument—noise that masks gravitational-wave signals of interest.

Now, a new study by the LIGO team describes a new type of mirror coating made of titanium oxide and germanium oxide, and outlines how it can reduce background noise in LIGO’s mirrors by a factor of two, thereby increasing the volume of space that LIGO can probe by a factor of eight.

“We wanted to find a material at the edge of what is possible today,” says Gabriele Vajente, a LIGO senior research scientist at Caltech and lead author of a paper about the work that appears in the journal Physical Review Letters. “Our ability to study the astronomically large scale of the universe is limited by what happens in this very tiny microscopic space.”

“With these new coatings, we expect to be able to increase the detection rate of gravitational waves from once a week to once a day or more,” says David Reitze, executive director of LIGO Laboratory at Caltech.

The research, which may have future applications in the fields of telecommunications and semiconductors, was a collaboration among Caltech; Colorado State University; the University of Montreal; and Stanford University, whose synchrotron at the SLAC National Accelerator Laboratory was used in the characterization of the coatings.

LIGO detects ripples in space-time using detectors called interferometers. In this setup, a powerful laser beam is split into two: Each beam travels down one arm of a large L-shaped vacuum enclosure toward mirrors 4 kilometers away. The mirrors reflect the laser beams back to the source from which they originated. When gravitational waves pass by, they will stretch and squeeze space by nearly imperceptible and yet detectable amounts (much less than the width of a proton). The perturbations change the timing of the arrival of the two laser beams back at the source.

Any jiggling in the mirrors themselves—even the microscopic thermal vibrations of the atoms in the mirrors’ coatings—can affect the timing of the laser beams’ arrival and make it hard to isolate the gravitational-wave signals.

“Every time light passes between two different materials, a fraction of that light is reflected,” says Vajente. “This is the same thing that happens in your windows: You can see your faint reflection in the glass. By adding multiple layers of different materials, we can reinforce each reflection and make our mirrors up to 99.999 percent reflective.”

“What’s important about this work is that we developed a new way to better test the materials,” says Vajente. “We can now test the properties of a new material in about eight hours, completely automated, when before it took almost a week. This allowed us to explore the periodic table by trying a lot of different materials and a lot of combinations. Some of the materials we tried didn’t work, but this gave us insights into what properties might be important.”

In the end, the scientists discovered that a coating material made from a combination of titanium oxide and germanium oxide dissipated the least energy (the equivalent of reducing thermal vibrations).

“We tailored the fabrication process to meet the stringent demands in optical quality and reduced thermal noise of the mirror coatings,” says Carmen Menoni, professor at Colorado State University and member of the LIGO Scientific Collaboration. Menoni and her colleagues at Colorado State used a method called ion beam sputtering to coat the mirrors. In this process, atoms of titanium and germanium are peeled away from a source, combined with oxygen, and then deposited onto the glass to create thin layers of atoms.

The new coating may be used for LIGO’s fifth observing run, which will begin in the middle of the decade as part of the Advanced LIGO Plus program. Meanwhile, LIGO’s fourth observing run, the last in the Advanced LIGO campaign, is expected to commence in the summer of 2022.

“This is a game changer for Advanced LIGO Plus,” says Reitze. “And this is a great example of how LIGO relies heavily on cutting-edge optics and materials science research and development. This is the biggest advance in precision optical coating development for LIGO in the past 20 years.”

LIGO mirror coatings get upgrade

More information:
Gabriele Vajente et al, Low Mechanical Loss TiO2:GeO2 Coatings for Reduced Thermal Noise in Gravitational Wave Interferometers, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.127.071101
Provided by
California Institute of Technology

Citation:
Extending our reach into the cosmos with new mirror coatings (2021, September 29)
retrieved 30 September 2021
from https://phys.org/news/2021-09-cosmos-mirror-coatings.html

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Technology

Apple warns against AirTag replacement batteries with bitter coatings

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While it may be some time before users are due to replace the button cell battery in their AirTag, Apple has issued a warning against buying products with bitterant coatings as they might not work with the device.

According to an Apple support document regarding AirTag battery replacement, users should avoid purchasing batteries with bitterant coatings.

“CR2032 batteries with bitterant coatings might not work with AirTag or other battery-powered products, depending on the alignment of the coating in relation to the battery contacts,” Apple says in the document, as spotted by The Loop.

The special treatment is used by some battery makers to prevent children from swallowing the small power sources. Bitterants are non-toxic chemicals that smell or taste bitter and are commonly used to discourage ingestion or inhalation of potentially dangerous products. Chemicals used by battery makers react with saliva to create an unpleasant taste.

Apple published the support page days after Australia issued a consumer advisory urging parents to keep AirTag away from children because its easily accessible battery is a choking hazard.

In the warning, the Australian Competition and Consumer Commission cited the ease at which AirTag can be opened, revealing the small CR2032 battery. To open AirTag, users simply press down on the stainless steel battery cover, twist counterclockwise until it stops rotating and lift it off.

The ACCC also said closing an AirTag’s chassis does not always ensure that the battery compartment is secure. Apple’s tracking device plays a tone when its cover makes contact with the battery, but that does not necessarily mean the device is locked, the body said.

At least one Australian retailer pulled the product from its shelves citing the same concerns outlined by the ACCC.

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