BC TECH
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EV Battery overview
Batteries are the key differentiator between the various EV manufacturers. The amount of energy stored in the battery determines the range of the EV, thought to be a major limitation on EV sales.

 Consumers tend to worry that an EV with a range of 80 to 250 miles on a single charge would be inconvenient for long trips due to the time it takes to recharge the battery. Commercial batteries need to ensure there is quick recharge and less time between charges
The lithium-ion battery is important because it makes EVs expensive than ICEs. Battery costs per kilowatt-hour (kWh) declined from roughly $1,000 per kWh in 2010 to $227 in 2016
Lithium-ion batteries made up 70 percent of the rechargeable battery market in 2016
BNEF projects that global production capacity for lithium-ion batteries will increase from 103 gigawatt-hours (GWh) in the first quarter of 2017 to 273 GWh by 2021.
The battery manufacturing supply chain has three main parts:

cell manufacturing,

module manufacturing, and

pack assembly.
The smallest, but most important, component of the lithium-ion batteries that power EVs is the

electrochemical cell,

which consists of three major parts: a cathode and an anode separated physically but connected electrically by an electrolyte.
A battery’s discharge results from the diffusion of lithium ions from the anode to the cathode through the electrolyte.
$TSLA Tesla produces its own modules and packs at both its “Gigafactory,” which opened in Nevada in 2017, and at its vehicle assembly plant in Fremont, California.

Tesla’s battery packs use cells from Gigafactory, while cells for the Model S & X are produced by Panasonic
The anode is typically made of graphite, while the electrolyte typically consists of organic carbonate solvents with dissolved lithium salts.
The anode is physically and electronically isolated from the cathode by a separator, often a thin porous plastic film through which the liquid electrolyte permeates.
The cathode has the most variation in its different form. 20 percent of the total cost of a finished lithium-ion battery pack comes from the cell stage of production.
Cells are assembled only as an intermediate good as part of the larger battery assembly process, for insertion into both EV batteries and batteries for other uses. Cells make up 75 percent of the cost of a battery pack, on average.
Multiple cells in a case with terminals attached form a module.
EV battery packs are the final stage of EV battery production. Battery packs consist of battery modules, electrical connections, and cooling equipment. 14 percent of the total cost of a finished lithium-ion battery pack comes from the pack stage of production.
Battery manufacturers design EV battery packs for specific vehicle models and tend to assemble them near the vehicle assembly plant.
Graphite is used in the anode of many EVs.
LG Chem batteries were a common brand of batteries among vehicles sold in the US. LG Chem assembles packs in Michigan and South Korea for Ford, General Motors, and Chrysler using Korean or U.S.-made cells, depending on the model.
Today battery packs cost $10–$12K depending on their capacity. Low battery prices are the key to unlock more affordable, higher volume electric cars.
$TSLA is aiming to reduce the cost of future packs to less than $6,000, which would put the cell cost at well under $100/kWh.
Other Battery manufacturers that supply to EV customers include CATL, Toshiba, Samsung SDI, BYD
In my next thread I will outline the new challengers, $QS, $THCB (Microvast), A123 Systems.

The current leaders are:
CATL $CATL
BYD $BYDDF
Guoxuan
Lishen Battery
AVIC Lithium Battery
Glossary:
1. ICE - Internal Combustion Engine
2. EV - Electric Vehicle
3. BNEF - Bloomberg New Energy Finance

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Nicolas
Nicolas
@necolas
A brief analysis and comparison of the CSS for Twitter's PWA vs Twitter's legacy desktop website. The difference is dramatic and I'll touch on some reasons why.

Legacy site *downloads* ~630 KB CSS per theme and writing direction.

6,769 rules
9,252 selectors
16.7k declarations
3,370 unique declarations
44 media queries
36 unique colors
50 unique background colors
46 unique font sizes
39 unique z-indices

https://t.co/qyl4Bt1i5x


PWA *incrementally generates* ~30 KB CSS that handles all themes and writing directions.

735 rules
740 selectors
757 declarations
730 unique declarations
0 media queries
11 unique colors
32 unique background colors
15 unique font sizes
7 unique z-indices

https://t.co/w7oNG5KUkJ


The legacy site's CSS is what happens when hundreds of people directly write CSS over many years. Specificity wars, redundancy, a house of cards that can't be fixed. The result is extremely inefficient and error-prone styling that punishes users and developers.

The PWA's CSS is generated on-demand by a JS framework that manages styles and outputs "atomic CSS". The framework can enforce strict constraints and perform optimisations, which is why the CSS is so much smaller and safer. Style conflicts and unbounded CSS growth are avoided.
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Kelly Ellis
Kelly Ellis
@justkelly_ok
So, I want to talk about how sexual harassment and fair pay are linked at Google (and beyond), because I think that's an angle that isn't being highlighted enough in the coverage of these walk-outs. I'm going to frame it largely around my personal experience there. Thread.

When I was sexually harassed by the director of the area I was working in, I was afraid to report it because I was worried that "getting him in trouble" would result in the subtle retaliation of missed leadership opportunities.

I wanted to continue working on the team I was on, because I'd gained a lot of very deep knowledge and expertise in that area, as well as reputation and camaraderie with the other folks working in that area. I didn't want to make the situation more "difficult."

To get promoted at Google, several need to happen: 1. you need opportunities for ownership and leadership above your current level (basically, opportunities to show you're working at the next level you're trying to get promoted to). The work you're "assigned" has a big impact.

2. You need glowing reviews from peers, *at or particularly above the level you're hoping to get promoted to.* Basically, you need people a lot more senior than you to say you're doing awesome work.
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Mike Metzler
Mike Metzler
@MTZLER
I’ve been flooded with Snapchat Spotlight questions after posting I’ve qualified for a payout 4 times. Here are the answers to the most common questions I’ve gotten in my DMs. These answers are my own experience and may differ from others .

Q: How will I know if I am getting paid?
A: You will get a message from Team Snapchat that looks like the below message 2-3 weeks after the snap has gone live. At this point it important that you verify your email address.


Q: How long after I’ve been notified I qualify, will I know for how much?
A: my experience is that usually 7-10 days after you get the qualifying message, you get a message with the amount, it will look like this. This message will include a unique access code for HyperWallet.


Q: How do I set up my HyperWallet?
A: Around three weeks after you get the payment amount you will get an email to your verified email from Snapchat Pay. It will look like this and will require you to fill out some tax forms, takes like 10 min.


Q: How long does it take to actually get the money in my account?
A: it took me like 7 days from when I had my HyperWallet approved before I got the money into my HyperWallet account. I recommend you set up auto withdraw. You can send money to PayPal, Venmo or bank account.
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Resist the Hologram - Stu Cvrk
Resist the Hologram - ...
@STUinSD
Thread – Dump the Legacy Media; Turn to These News Sources

A. We all need sources less tainted by the Big Tech/globalist narratives that are echoed repeatedly throughout the legacy media. My brother sent me a list of alternatives from the Noq report.
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Abadesi (she/her)
Abadesi (she/her)
@Abadesi
🙋🏾‍♀️ In 2011, I was hired into my first junior role in tech @Groupon

👩🏾‍💻 By 2020, I was headhunted into a VP role in a global tech company @Brandwatch

🤖 I achieved this progression in less than a decade, without ANY coding skills

🔮 How did I do it?

*a thread*


🤓 I established a track record of results.

💪🏾 No magic formula can replace hard work: do your job well & hit all the targets you are set.

😬 When you're struggling, ask for help so you can stay on track to get results, or collaboratively adjust targets.

🎨 I stayed creative.

🧙🏿‍♀️ When challenges arose I was bold enough to try new solutions. Not everything worked, but constantly trying produced valuable innovations.

🧠 I was proactive in finding new, better ways to get the job done.

🤩 I was a self-promoter. I recorded my achievements & ensured they were mentioned in any performance / compensation reviews.

😎 I put myself forward for any opportunities to gain recognition e.g. speaking opportunities or awards.

👀I actively worked on gaining visibility.

🙂 I was myself. Some say you need to be ruthless to succeed. I don't buy it. I'm a nice person so I'm nice at work, too.

❤️ I didn't fake it. I always acted on my values, and spoke up when something didn't feel right. I showed integrity.

🤗 I was a team player. To everyone.
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Roger Grosse
Roger Grosse
@RogerGrosse
Important paper from Google on large batch optimization. They do impressively careful experiments measuring # iterations needed to achieve target validation error at various batch sizes. The main "surprise" is the lack of surprises. [thread]

https://t.co/7QIx5CFdfJ


The paper is a good example of lots of elements of good experimental design. They validate their metric by showing lots of variants give consistent results. They tune hyperparamters separately for each condition, check that optimum isn't at the endpoints, and measure sensitivity.

They have separate experiments where the hold fixed # iterations and # epochs, which (as they explain) measure very different things. They avoid confounds, such as batch norm's artificial dependence between batch size and regularization strength.

When the experiments are done carefully enough, the results are remarkably consistent between different datasets and architectures. Qualitatively, MNIST behaves just like ImageNet.

Importantly, they don't find any evidence for a "sharp/flat optima" effect whereby better optimization leads to worse final results. They have a good discussion of experimental artifacts/confounds in past papers where such effects were reported.
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Nikita Poojary
Nikita Poojary
@niki_poojary
Mr. Vijay Kedia built a net worth of over Rs. 800 crores.

But you probably never read past that headline.

So I binged hours of interviews to learn his investing principles and strategies.

Here are 20 lessons on investing from @VijayKedia1 Sir:

Collaborated with @AdityaTodmal


Before I start, a quick disclaimer, please don't ape his portfolio.

As the entry price, horizon and risk appetite would be far different than yours.

Rather lets draw inspiration and try to learn his stock picking skills.

Now let's DIVE IN👇

1/ Started off as a trader:

- Soon, beginner’s luck started to fade out and loses started to mount, to an extent where his mother was about to sell her ornaments.

- Although he was able to dodge the situation.

- This incident taught him the biggest lesson to have a stop-loss.

2/ Punjab Tractors:

- In 1990, he made his first investment by putting in his 10-years savings of Rs 35,000 in this stock, based on a news trigger that tractor industry will witness a turnaround.

- It worked and fetched him 4-5 times which he calls it as a fluke.


3/ He believes that an investor must possess three qualities:

i. Knowledge,
ii. Courage, and
iii. Patience.
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Billy Bostickson \U0001f3f4\U0001f441&\U0001f441 \U0001f193
Billy Bostickson 🏴👁&👁 ...
@BillyBostickson
Keep dwelling on this:
Further Examination of the Motif near PRRA Reveals Close Structural Similarity to the SEB Superantigen as well as Sequence Similarities to Neurotoxins and a Viral SAg.

The insertion PRRA together with 7 sequentially preceding residues & succeeding R685 (conserved in β-CoVs) form a motif, Y674QTQTNSPRRAR685, homologous to those of neurotoxins from Ophiophagus (cobra) and Bungarus genera, as well as neurotoxin-like regions from three RABV strains

(20) (Fig. 2D). We further noticed that the same segment bears close similarity to the HIV-1 glycoprotein gp120 SAg motif F164 to V174.
https://t.co/EwwJOSa8RK


In (B), the segment S680PPRAR685 including the PRRA insert and highly conserved cleavage site *R685* is shown in van der Waals representation (black labels) and nearby CDR residues of the TCRVβ domain are labeled in blue/white
https://t.co/BsY8BAIzDa


Sequence Identity %
https://t.co/BsY8BAIzDa
Y674 - QTQTNSPRRA - R685
Similar to neurotoxins from Ophiophagus (cobra) & Bungarus genera & neurotoxin-like regions from three RABV strains
T678 - NSPRRA- R685
Superantigenic core, consistently aligned against bacterial or viral SAgs
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Tej Dosa \U0001f602\U0001f9e0
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(A THREAD)

18 Things I Would Do At 18:

I was a dumb 18-year-old. I thought I had the world figured out. I didn't.

I stayed up till the wee hours. Drank every liquor invented.

Partied non-stop. Woke up after noon.

Surfed the web aimlessly.

Read BS self-help.

Repeat.

If I could do it all over again, here's 18 things I would do...

PHASE ONE: GET MY MIND RIGHT

ACTION #1: Break the chains - I wish I made the decision earlier. I didn't. I was scared. Anxious. Nervous. I knew once I made the decision, there was no going back.

Don't be like me.

Make the decision at 18. The decision to pave your own path in life. To go against the herd. To choose your own adventure. To commit to whatever sets your heart on fire.

ACTION #2: Cut off every negative person in your life.

Scroll through the contacts in your phone...

Notice how the names make you feel.

Delete any and all names that fill you with doubt and negativity.

ACTION #3: Condition your mind to embrace the producer mindset instead of the consumer mindset.

Consume 20% of the time. Produce 80% of the time.

Case closed.

ACTION #4: Set an intention to make $10k a month and write it out every MORNING and NIGHT as if you already achieved it (in the past tense).

Visualize yourself already having the money as you write.

Cheesy?

Yes.

Does it work?

Yes.

PHASE TWO: EDUCATION
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Suhas S. Hardutt
Suhas S. Hardutt
@HarduttSuhas
THE BATTLE OF SARAIGHAT (1671)

Lachit Borphukan's humiliation of Aurangzeb.

The battle of Saraighat was a naval engagement fought on the Brahmaputra river near Saraighat between the M0ghul empire and Ahom kingdom in 1671.

Guts, resolve and glory!

(Elaborate thread)


Koch was a state situated between the dominions of M0ghuls and Ahoms. For Ahoms, it was a buffer state for keeping M0ghul territorial expansions at bay.(1)

Times changed when the ruler of the Koch kingdom, Nara Narayana passed away in 1587 resulting in Koch being divided into 2. Western Koch was ruled by his son Lakshmi Narayan and the eastern Koch by his nephew, Raghudev.(2)

Lakshmi Narayan formed an alliance with M0ghuls after which he attacked Parikshit, son of Raghudev, in 1602. Parikshit Narayan was defeated while his brother Bali Narayan took refuge in the Ahom Kingdom.(3)

The M0ghuls used it as a pretext to invade Ahom kingdom. The first battle between them took place in 1615 leading to a series of engagements in which both sides had their shares of ups and downs resulting in a stalemate.(4)
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