According to Abrams' Law, the compressive strength of concrete is inversely proportional to the water-cement ratio, provided the mix is fully compacted. If you add too much water, it creates large spaces or capillary pores inside the concrete when the excess, unreacted water evaporates.
This results in a highly porous, weaker structure that can crack under loads. On the other hand, if you add too little water, the cement particles will not fully react, making the concrete harsh, difficult to place, and prone to internal honeycomb voids. //
Understanding how to calculate water cement ratio helps maintain consistent concrete quality on site. The formula is straightforward:
Water Cement Ratio = Weight of Water ÷ Weight of Cement
For example:
If one bag of cement weighs 50 kg and the required water to cement ratio is 0.5, the water required will be:
Water Required = 0.5 × 50 kg = 25 litres
This means 25 litres of water should be used for one bag of cement to maintain the correct water cement ratio in concrete. //
Testing the Water-Cement Ratio: The Slump Test
The slump test is a simple method used to check the workability of fresh concrete. While it does not directly measure the water-cement ratio, it helps indicate whether the water content is appropriate.
In this test, fresh concrete is placed into a cone-shaped mould. When the mould is lifted, the concrete settles or “slumps.” The amount of slump shows the consistency of the mix. A higher slump usually indicates higher water content, while a lower slump indicates a stiffer mix.
This test helps builders ensure the water ratio for concrete mix remains suitable for proper placement and compaction.
“The damage to our infrastructure spanned multiple Availability Zones and exceeded what our regional and multi-AZ services are designed to withstand,” the AWS update said.
A good design doc can save you years of development time. Writing a design doc forces you to think through important decisions before you waste time on the wrong implementation. It’s also the best way to coordinate design decisions among teammates and partner teams.
I’ve written design docs as a developer at Google, Microsoft, and within my own companies. The specifics vary, but the underlying principles remain the same. A design doc articulates the hard problems you’re solving and helps your teammates give you feedback.
Below, I share my approach to creating effective design docs and explain what belongs in a design doc and what does not.
There is an old AWS quote that has aged in a particularly interesting way.
In 2017, CBS asked AWS executive Matt Wood a rather pointed question:
CBS: “I don’t mean to give anyone ideas, but let’s say I figured out that one of these unmarked buildings was an AWS data center, and I blew it up. Are you saying that it’s so backed up and redundant that you probably wouldn’t notice?”
AWS: “Yeah, you wouldn’t notice. I mean, we might be a bit upset, but you wouldn’t notice!”
Nine years later, somebody effectively ran the experiment, although on a much larger scale than the loss of a single building, and people did, in fact, notice. //
I Guess Maybe Now They’ll Do 3-2-1 Backups
The gold standard for data protection is “3 copies, 2 different kinds of media, 1 of which is offsite”.
I’m all for the cloud, but if it’s important data and you’re limited to keeping all of your cloud data in one set of buildings…then for pity’s sake, have off-site backups. You don’t need to have another failover site ready to light up if Amazon goes down for you, but you shouldn’t lose the data. Replicate it off-site. I mean, forget even acts of war – what if hackers get into your systems? Into Amazon’s systems? What if an employee goes rogue? What if, what if…
A replicated off-site solution with ransomware protection and disk snapshots (or heaven forbid, tape!) doesn’t mean you can restore service quickly, but it means you won’t lose the data. In other words, go ahead and say “if we have to go to that dire situation, we’re not promising a recovery time objective (RTO). But we are promising a Recovery Point Objective (RPO).”
Losing data sucks.
Jonathan Richards 1Silver badge
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Re: Ooh cms
Upvoted. Librarianship 101, or the correct principles for an office filing system which brought myriads of companies successfully through generations of business and progress. The oldest of those companies have curated archives that you can still find documents in. Good luck with that in a hundred years for any of the software solutions kicking around now.
The nightmare began when we stopped filing things in carefully chosen places, or alternatively carefully indexing things placed in a managed store. Some clown thought that having a list of all the words in all the documents would make it easy to find what one was looking for. Repeat after me: the set of words in a document does not tell you what the document is about. cf Manila and manila!
Jason BloombergSilver badge
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Re: the discipline of using COBOL on show
Is it "the discipline of using COBOL" on show here, or simply that COBOL is so well defined and simplistic that it's easy to convert most COBOL programs to some other language?
I have written a number of transpilers to convert from one language to another. They work brilliantly so long as the source is within the transpiler's constraints. Otherwise update the transpiler or simplify the source.
It's been so long since I had to deal with COBOL the only thing I remember about it, which elicits a smile every time, is the classic -
PERFORM X UNTIL EXHAUSTED //
Roland6Silver badge
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Re: the discipline of using COBOL on show
No COBOL conversion was performed here. As the original commentant pointed out: the ability to specify a problem in a form that permits the writing of a COBOL program also permits the creation of a specification that can be I’m-lamented in a different langauge.
Remember an AI prompt is just a specification written in a way an AI code generator can parse. The writing of specifications is something Imsuspect many older programmers did and do, but many code junkies have avoided doing…
Application Guidance Notes
THE CARBON LIES
TRILLIONS STOLEN
MASS PSYCHOSIS
Rising CO2 is NOT caused by fossil fuels.
Rising CO2 is NOT harmful.
Both claims are categorically false.
Both are foreclosed by direct measurement.
Every carbon capture project, every carbon credit scheme, every Net-Zero pledge, every fossil-fuel restriction, every carbon footprint calculation rests on physics that has been falsified.
Trillions of dollars. Two lies. Here's the TRUTH.
LIE #1: Rising atmospheric CO2 is harmful.
There is NO evidence that increasing CO2 at current atmospheric concentrations causes ANY harm to humans, ecosystems, or the planet. NONE.
The harm claim typically routes through "warming." Two problems.
First: there is no physical quantity called "global temperature." What is reported as "global mean surface temperature" is an area-weighted arithmetic mean of intensive-variable surface readings from thermometers of varying kind, siting, and coverage. An arithmetic mean of intensive variables is not itself an intensive variable. It has no physical meaning whatsoever. Units belong to physical quantities. GMST is a number, not a temperature.
Second: even accepting the FALSE temperature framing, the radiative forcing from CO2 is trivially small. Happer and van Wijngaarden's line-by-line calculations from the HITRAN spectroscopic database give clear-sky CO2 forcing of 2.97 W/m² for doubling from 400 to 800 ppm at the top of the atmosphere.
The saturation is direct: doubling CO2 reduces outgoing radiation by only about 1%. Applying any reasonable cloud correction — Earth averages ~67% cloud cover, and clouds absorb strongly in CO2's principal 15 μm band, already blocking most of the outgoing radiation CO2 would absorb — reduces all-sky forcing below 1 W/m², plausibly below 0.5 W/m².
That is undetectable. Solar input at any surface location varies by hundreds of W/m² diurnally, dozens of W/m² seasonally, and dozens of W/m² between adjacent cloudy and clear moments. A signal of 0.5 W/m² does not rise above ordinary variability. There is nothing there to measure.
John Clauser (Nobel Prize in Physics 2022) has emphasized the further point: clouds are Earth's actual thermostat, responding to surface conditions on the scale of hours. No cloud feedback in any general circulation model has been validated against observation. A calculation that omits the dominant regulatory mechanism cannot testify to how the system responds.
Meanwhile, what CO2 does is measured, direct, and life-sustaining.
CO2 is the direct substrate of photosynthesis. Plants are the base of the entire food chain. Every calorie consumed by every animal, humans included, begins as photosynthesis. More atmospheric CO2 means more photosynthesis, more crop yield, more biomass. More CO2 means more life.
Satellite measurements since 1982 show Earth's leaf area has increased substantially, driven primarily by CO2 fertilization. Agricultural yields have risen with atmospheric CO2. Commercial greenhouse operators intentionally maintain CO2 at 1,000-1,500 ppm because plants thrive there.
The geological record: atmospheric CO2 has ranged from 180 ppm (glacial minima) to 7,000 ppm (Cambrian). Life flourished at the high end. The genuine danger threshold is the low end, near 150 ppm, below which C3 photosynthesis fails and terrestrial life largely ends.
LIE #2: Rising atmospheric CO2 is caused by human fossil fuel burning.
The isotopic mass balance forecloses this claim.
Fossil fuel carries δ¹³C = −28‰. The measured signature of the actual net addition to the atmosphere, from six independent records spanning 500-1000 years (four Scripps stations, Cape Grim Air Archive, Law Dome ice core, Caribbean sclerosponge), is δ¹³C = −13.2‰.
Under the physically dictated mass partition equation, the fossil fraction of the net atmospheric addition is approximately ZERO.
For fossil to dominate the atmospheric increase (the IPCC and @CO2Coalition FALSELY claim), non-fossil sources and sinks would need to carry δ¹³C = +46‰ or heavier. No terrestrial reservoir on Earth carries this signature. Not the ocean. Not the biosphere. Not volcanic. Not carbonate weathering. Nothing on this planet. This is two orders of magnitude away from REALITY. Not even close.
Trillions stolen.
Global spending on climate policy exceeded $2 trillion in 2024. McKinsey estimates cumulative spending of $275 trillion through 2050 under the industry-standard Net Zero 2050 scenario, roughly 7.5% of global GDP annually for three decades. Carbon credit markets alone moved over $100 billion in 2023, trading permission slips against a claim the physics forecloses.
Every dollar spent on carbon capture, offset schemes, Net-Zero infrastructure, carbon credits, and fossil-fuel restriction is STOLEN from productive economies on the basis of physics that has been falsified by direct measurement.
This is not waste. It is thievery.
Mass psychosis.
But there may be a price to pay for a quiet Atlantic hurricane season. //
Last week, the Atlantic hurricane season blew through its traditional peak—which comes around September 10—with nary a tropical wave in sight, let alone a storm or hurricane.
This is remarkable. Usually this is the time of year when sea surface temperatures reach their warmest in the tropics, and with a favorable atmosphere it should be smooth skating for tropical systems. But this year, the main region where most tropical systems develop is choked with Saharan dust and wind shear.
A negative sequence current arises when the voltage and current in a power system are unbalanced. This type of current produces a reverse rotating magnetic field in the air gap, which has a synchronous speed but rotates in the opposite direction to the rotor. This reverse rotating field is detected by points on the rotor surface and can cause damage to rotating machinery if left unchecked. It is important to have Negative Sequence Current Ratings for generators as it is expected that they will not be connected 100% Negative-Sequence all the time, with three statements about the power system needing to be true for this to occur. Excessive negative phase sequence current can cause excessive heating, vibration, and bearing wear, leading to long-term damage or even machinery failure.
negative sequence current
What is pupillary distance?
Pupillary distance (PD) measures the distance between the centers of your pupils and is used to center a prescription lens accurately in your frames. Your optician will usually measure your PD or you can use our digital PD ruler to measure it quickly online.
Before you discovered Zenni, when you paid 10 times more for glasses you bought at the local optical store, the optician adjusted them for you.
But you can do it yourself, by following these easy-to-understand instructions.
Don’t worry. Your frame can stand a little bending. And when you’ve been wearing them for a while and they get out of shape again, just repeat the adjustments, and you’re good to go!
From custom taskbars to secret productivity tweaks, Windhawk gives you complete control over your PC, no registry hacks required. //
Windhawk is a free and open-source tool that helps you tweak aspects of Windows and your apps in ways that Microsoft and developers would never allow, combining a sophisticated code injection technique with an intuitive interface. The project's developer, Michael Maltsev, says it now has 1.5 million users, and Microsoft employees are increasingly enthusiastic about it, too. March Rogers, partner director of design at Microsoft, recently called it "amazing."
Freedom to build what you want
FreeCAD is an open-source parametric 3D modeler made primarily to design real-life objects of any size. Parametric modeling allows you to easily modify your design by going back into your model history and changing its parameters.
Create 3D from 2D & back
FreeCAD allows you to sketch geometry constrained 2D shapes and use them as a base to build other objects. It contains many components to adjust dimensions or extract design details from 3D models to create high quality production ready drawings.
For professional design needs...
FreeCAD is a powerful and evolving open-source parametric 3D modeler, well-suited for many professional and technical tasks. Each new release marks a milestone in stability and usability. FreeCAD puts you in control - no licensing fees, no vendor lock-in. It's not just cost-effective - it’s yours to adapt and build upon.
...And for everything else
Whether you're prototyping, 3D printing, designing furniture, or learning CAD, FreeCAD offers the tools to support your creativity. With a strong community, extensive documentation, and a growing ecosystem of add-ons, it’s a great place to start - and to grow. No sign-up, no paywall, no restrictions. Just open-source freedom at your fingertips.
AnyDesk is a remote desktop application distributed by AnyDesk Software GmbH. The proprietary software program provides platform-independent remote access to personal computers and other devices running the host application. It offers remote control, file transfer, and VPN functionality.
Each release is supported by the Security Officer for a limited time only.
The designation and expected lifetime of all currently supported branches and their respective releases are given below. The Expected EoL (end-of-life) column indicates the earliest date on which support for that branch or release will end. Please note that these dates may be pushed back if circumstances warrant it.
It's obvious this is an attempt to ban open-source AI so the new "FAA of AI" can control AI. Even if it's as dangerous as they say, they have no way to control what China does. Which means this campaign for regulation won't actually meet any of their stated aims. //
What we are seeing is a massive, pretty obviously coordinated campaign by AI researchers, companies, NGOs, and politicians to strangle competition in an industry and, as I will show, save the financial bacon of the top AI companies that are vastly overextended financially because they have made contractual commitments that they simply have no prospect of paying for. //
Today's "bull market" is almost exclusively driven by the rapid rise of AI-adjacent companies, and if the AI companies can't deliver massive growth, all these other companies are cooked as well. Data centers will have no customers, cloud compute will have nothing to do, and Nvidia chips won't be worth 10x gold. //
None of these companies is suggesting that AI be shut down; they are asking for a massive regulatory infrastructure that works with them, reduces their costs, possibly subsidizes their investments, and destroys competitors as insufficiently careful and secure. //
The solution is to ensure companies face liability for any damage they cause. Government regulators are utterly incapable of regulating anything as massively complicated and rapidly developing as AI, but you can be darn sure that if these companies face multi-billion-dollar liability claims, they will be quite careful about what they release.
Which do you trust more: a GS-12 based in Washington assigned to evaluate a model he could never understand, or a bank of lawyers warning CEOs that screwing up could cost them $20 billion? //
Will AI kill everybody off at some point in the future? I doubt it, but I can't say for sure. What I can say with certainty is that AI companies, because of their own financial mismanagement, face an existential threat and want (NEED) the government to bail them out, and need an excuse to get it to do so.
What you saw in this week's frenzy is the excuse they chose.
In the 1960s the sugar industry paid three Harvard scientists to publish a review blaming fat for heart disease and clearing sugar. The payments were discovered in 2016 by researchers at the University of California, San Francisco, who found the internal industry documents and published them in JAMA Internal Medicine.
The documents showed that the Sugar Research Foundation, now called the Sugar Association, paid the equivalent of about 50,000 dollars in today's money to three Harvard researchers to write a review of the evidence on sugar, fat, and heart disease. The review, published in the New England Journal of Medicine in 1967, concluded that fat was the dietary villain and that sugar was innocent. The funding was not disclosed.
The consequences lasted fifty years. Dietary guidelines in the United States shifted toward low-fat diets, and the food industry replaced fat with sugar in thousands of products. Americans ate less fat and more sugar for three decades, and rates of obesity and type 2 diabetes rose in parallel. The science that drove the shift was paid for by the industry that benefited from it.
The 2016 paper, led by Cristin Kearns, found that the Sugar Research Foundation had set the review's objective in advance, selected the studies to include, and reviewed drafts before publication. The Harvard researchers accepted the money and the direction without question, and the journal published the result without requiring disclosure of the funding.
Early warning signals of the coronary heart disease (CHD) risk of sugar (sucrose) emerged in the 1950s. We examined Sugar Research Foundation (SRF) internal documents, historical reports, and statements relevant to early debates about the dietary causes of CHD and assembled findings chronologically into a narrative case study. The SRF sponsored its first CHD research project in 1965, a literature review published in the New England Journal of Medicine, which singled out fat and cholesterol as the dietary causes of CHD and downplayed evidence that sucrose consumption was also a risk factor. The SRF set the review's objective, contributed articles for inclusion, and received drafts. The SRF's funding and role was not disclosed. Together with other recent analyses of sugar industry documents, our findings suggest the industry sponsored a research program in the 1960s and 1970s that successfully cast doubt about the hazards of sucrose while promoting fat as the dietary culprit in CHD. Policymaking committees should consider giving less weight to food industry-funded studies and include mechanistic and animal studies as well as studies appraising the effect of added sugars on multiple CHD biomarkers and disease development.