Posts about Engineering

Toyota Mirai – Hydrogen Fuel Cell Electric Car

I am curious, even skeptical, about the potential for hydrogen fuel cell versus battery passenger cars. I do respect Toyota and so am wondering if they do indeed see something that most others are missing.

The current production Toyota Mirai has a range of 650 km.

I do think hydrogen fuel cells may provide a better option for larger vehicles (maybe even shipping), but I have done next to no research on this so I may be wrong.

It seem unlikely to me that hydrogen fuel cell passenger cars are going to make it but I would be happy to be wrong. Perhaps the advantages will overcome what seem to me to be challenges that are going to prevent them from being successful. I am confused about how committed to this strategy Toyota is (which makes me question my belief that hydrogen fuel cell passenger cars are not going to be successful).

Related: Toyota Engineering Development ProcessToyota Develops Thought-controlled WheelchairHow to Develop Products like Toyota (2011)Innovation at ToyotaElectric Cars (post on our blog in 2007)Toyota Scion iQ: 37 MPG (2011)Toyota Engineers a New Plant: the Living Kind (2005)

Science Explained: Wind Powered Vehicle Traveling Faster Than the Wind

This is an interesting explanation of a the physics involved with vehicle propulsion. And it is a great video showing the scientific method at work.

They only touch on it a little bit but the need for creating 4 versions of the small treadmill device to illustrate the principles in action is a great example of how science inquiry and engineering work. There are often many failed attempts before an engineering solution to the issue involved can be properly created (video on Xyla Foxlin’s efforts: Building the Vehicle Physicists Called Impossible).

Enjoy the videos.

Veritasium is also offering 3 prizes to split the $10,000 for 1 minute videos that highlight science communicators with his Veritasium Science Communication Contest.

Related: The Amazing Reality of Genes and The History of Scientific InquiryScience Explained: Momentum For String of Metal BeadsCircumhorizontal Arcs – Fire Rainbows – Cloud RainbowsScientific Inquiry Leads to Using Fluoride for Healthy Teeth

Huge Proposed Increases in USA Government Science and Engineering Support

The Biden administration has proposed greatly increasing USA government spending on science and engineering. They are proposing levels last seen in the 1960s when the USA was most committed to science and engineering spending (as most visibly seen in support for NASA).

Advance U.S. leadership in critical technologies and upgrade America’s research infrastructure. U.S. leadership in new technologies—from artificial intelligence to biotechnology to computing—is critical to both our future economic competitiveness and our national security. Based on bipartisan proposals, President Biden is calling on Congress to invest $50 billion in the National Science Foundation (NSF), creating a technology directorate that will collaborate with and build on existing programs across the government. It will focus on fields like semiconductors and advanced computing, advanced communications technology, advanced energy technologies, and biotechnology. He also is calling on Congress to provide $30 billion in additional funding for R&D that spurs innovation and job creation, including in rural areas. His plan also will invest $40 billion in upgrading research infrastructure in laboratories across the country, including brick-and-mortar facilities and computing capabilities and networks. These funds would be allocated across the federal R&D agencies, including at the Department of Energy. Half of those funds will be reserved for Historically Black College and Universities (HBCUs) and other Minority Serving Institutions, including the creation of a new national lab focused on climate that will be affiliated with an HBCU.

Establish the United States as a leader in climate science, innovation, and R&D. The President is calling on Congress to invest $35 billion in the full range of solutions needed to achieve technology breakthroughs that address the climate crisis and position America as the global leader in clean energy technology and clean energy jobs. This includes launching ARPA-C to develop new methods for reducing emissions and building climate resilience, as well as expanding across-the-board funding for climate research. In addition to a $5 billion increase in funding for other climate-focused research, his plan will invest $15 billion in demonstration projects for climate R&D priorities, including utility-scale energy storage, carbon capture and storage, hydrogen, advanced nuclear, rare earth element separations, floating offshore wind, biofuel/bioproducts, quantum computing, and electric vehicles, as well as strengthening U.S. technological leadership in these areas in global markets.

Eliminate racial and gender inequities in research and development and science, technology, engineering, and math. Discrimination leads to less innovation: one study found that innovation in the United States will quadruple if women, people of color, and children from low-income families invented at the rate of groups who are not held back by discrimination and structural barriers. Persistent inequities in access to R&D dollars and to careers in innovation industries prevents the U.S. economy from reaching its full potential. President Biden is calling on Congress to make a $10 billion R&D investment at HBCUs and other MSIs. He also is calling on Congress to invest $15 billion in creating up to 200 centers of excellence that serve as research incubators at HBCUs and other MSIs to provide graduate fellowships and other opportunities for underserved populations, including through pre-college programs.

This text is from The White House Infrastructure Plan (The American Jobs Plan). Likely this link will stop working in several years (once a new administration takes over.
photo of NASA's Mars Rover: Curiosity
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Creating Low-cost Construction Materials Using Recycled Plastic Waste

Nzambi Matee is a materials engineer and head of Gjenge Makers (in Kenya), which produces sustainable low-cost construction materials made of recycled plastic waste and sand. For her work, Nzambi Matee was recently named a Young Champions of the Earth by the United Nations Environment Programme.

Building blocks for a greener Nairobi

Through trial and error, she and her team learned that some plastics bind together better than others. Her project was given a boost when Matee won a scholarship to attend a social entrepreneurship training programme in the United States of America. With her paver samples packed in her luggage, she used the material labs in the University of Colorado Boulder to further test and refine the ratios of sand to plastic.

It is wonderful to see young people using an understanding of engineering to find ways to improve the world. Taking waste plastic and creating usable products will help reduce pollution and create a better world. We need quite a bit of effort to deal with plastic waste, so I look forward to learning about many more ideas turned into practical solutions in the real world.

Related: Cleaning Up the Plastic Pollution in Our OceansPedal Powered Washing MachineProtecting Cows with Lion LightsDrone Deliveries to Hospitals in Rwanda

I Just Finished Statistics for Experimenters and I Cannot Praise it Enough

Guest post by Michael Betancourt.

I just finished Box, Hunter, and Hunter (Statistics for Experimenters) and I cannot praise it enough. There were multiple passages where I literally giggled. In fact I may have been a bit too enthusiastic about tagging quotes beyond “all models are wrong but some are useful” that I can’t share them all.

photo of Statistics for Experimenters with many blue bookmarks shown

I wish someone had shared this with me when I was first learning statistics instead of the usual statistics textbooks that treat model development as an irrelevant detail. So many of the elements that make this book are extremely relevant to statistics today. Some examples:

  • The perspective of learning from data only through the lens of the statistical model. The emphasis on sequential modeling, using previous fits to direct better models, and sequential experiments, using past fits to direct better targeted experiments.
  • The fixation on checking model assumptions, especially with interpretable visual diagnostics that capture not only residuals but also meaningful scales of deviation. Proto visual predictive checks as I use them today.
  • The distinction between empirical models and mechanistic models, and the treatment of empirical linear models as Taylor expansions of mechanistic models with covariates as _deviations_ around some nominal value. Those who have taken my course know how important I think this is.
  • The emphasis that every model, even mechanistic models, are approximations and should be treated as such.
  • The reframing of frequentist statistical tests as measures of signal to noise ratios.
  • The importance of process drift and autocorrelation in data when experimental configurations are not or cannot be arbitrarily randomized.
  • The diversity of examples and exercises using real data from real applications with detailed contexts, including units everywhere.

Really the only reason why I wouldn’t recommend this as an absolute must read is that the focus on linear models and use of frequentist methods does limit the relevance of the text to contemporary Bayesian applications a bit.

Texts like these make me even more frustrated by the desire to frame movements like data science as revolutions that give people the justification to ignore the accumulated knowledge of applied statisticians.

Academic statistics has no doubt largely withdrawn into theory with increasingly smaller overlap with applications, but there is so much relevant wisdom in older applied statistics texts like these that doesn’t need to be rediscovered just reframed in a contemporary context.

Oh, I forgot perhaps the best part! BHH continuously emphasizes the importance of working with domain experts in the design and through the entire analysis with lots of anecdotal examples demonstrating how powerful that collaboration can be.

I felt so much less alone every time they talked about experimental designs not being implemented properly andthe subtle effects that can have in the data, and serious effects in the resulting inferences, if not taken into account.

Michael Betancourt, PhD, Applied Statistician – long story short, I am a once and future physicist currently masquerading as a statistician in order to expose the secrets of inference that statisticians have long kept from scientists. More seriously, my research focuses on the development of robust statistical workflows, computational tools, and pedagogical resources that bridge statistical theory and practice and enable scientists to make the most out of their data.
Twitter: @betanalpha
Website: betanalpha
Patreon: Michael Betancourt

Related: Statistics for Experimenters, Second EditionStatistics for Experimenters in SpanishStatistics for Experimenters ReviewCorrelation is Not Causation

Appropriate Technology: a Microscope and Centrifuge for Under $1

Malaria is estimated to have killed more than half the people that have ever lived. And it continues to kill millions. One big challenge is diagnosing malaria is difficult (those infected have flu like symptoms).

The video shows two great appropriate technology solutions to help diagnose malaria and save millions of lives. Manu Prakash from Stanford talks about 2 of his labs’ inventions the Foldscope and the Paperfuge. Combined these cost only 68 cents and they can be used to diagnose Malaria. Both of these are examples not only of simple, brilliant design, but of how engineering is used to make a positive dent in the world.

Read more about the Paperfuge: an ultra-low cost, hand-powered centrifuge inspired by the mechanics of a whirligig toy (open access paper).

This solution also shows the huge benefit people everywhere have gained when immigrants can take their skills and desires to institutions like Stanford to create solutions that greatly benefit the world. This powerful force has been creating huge benefits that we all have enjoyed for decades.

Related: Appropriate Technology and Focus on Improving Lives at MIT (2014)$1 Device To Give Throat Cancer Patients Their Voice Again (2016)Video showing malaria breaking into cell (2011)Engineering: Cellphone Microscope (2009)One Scientists 20 Year Effort to Defeat Dengue Fever (2012)

20 Most Popular Post on the Curious Cat Science and Engineering Blog in 2018

These were the most popular (by number of page views) posts on our blog in 2018.

Red-tailed hawk with squirrel

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Scientists and Engineers in Congress After the Recent Elections in the USA

The recent elections in the USA added to those serving in congress with STEM (science, technology, engineering and math) backgrounds.

USA Capital Building

US Capital Building in Washington DC by John Hunter.

Here is a list of elected representatives in the USA congress with science, technology, engineering and math backgrounds (after the 2018 election).

Name State BS Notes Link
Ralph Abraham Louisiana MD bio
Ami Bera California biological sciences MD bio
Tony Cárdenas California electrical engineering bio
Sen. Bill Cassidy Louisiana biochemistry MD bio
Sean Casten Illinois molecular biology and biochemistry MS biochemical engineering and engineering management, 2018* bio
Chris Collins New York mechanical engineering bio
Joe Cunningham South Carolina ocean engineering 2018* bio
Jeff Van Drew New Jersey D.D.S. (Dentist), 2018* bio
Bill Foster Illinois physics PhD physics bio
Brett Guthrie Virginia mathematical economics bio
Sen. Martin Heinrich New Mexico mechanical engineering bio
Kevin Hern Oklahoma electro-mechanical engineering 2018* bio
Chrissy Houlahan Pennsylvania engineering MS technology and policy, 2018* bio
Joe Kennedy III Massachusetts management science and engineering bio
Ted Lieu California computer science bio
Name State BS Notes Link
Dan Lipinski Illinois mechanical engineering engineering-economic systems (MS) bio
Elaine Luria Virginia physics masters in engineering management, 2018* bio
Jerry McNerney California mathematics PhD bio
Seth Moulton Massachusetts physics bio
Pete Olson Texas computer science (BA)
Sen. Jacky Rosen Nevada psychology associat’s degree in computing and information technology
Raul Ruiz California MD, 2018* bio
Brad Schneider Illinois industrial engineering bio
Kurt Schrader Oregon Dr. of Veterinary Medicine bio
Kim Schrier Washington astrophysics MD, 2018* bio
John M. Shimkus Illinois general engineering bio
Paul Tonko New York mechanical and industrial engineering bio
Lauren Underwood Illinois nursing MS in Nursing and Master of Public Health, 2018* bio
Steve Watkins Kansas engineering 2018* bio



Those with notes including “2018*” means they were newly elected to the congress in 2018.

Please send any information on possible additions to this list (see the continually updated list).

Related: Scientific Research Spending Cuts in the USA and Increases Overseas are Tempting Scientists to Leave the USA (2013)The Science Gap and the EconomyScientists and engineers in the USA Congress in 2008 (scroll down the page to see 2008) – Diplomacy and Science ResearchUnless We Take Decisive Action, Climate Change Will Ravage Our Planet (2009)Silicon Valley Shows the Power of Global Science and Technology Workforce

Protecting Cows with Lion Lights

It is wonderful to see what great things people accomplish to improve their lives using sensible, and fairly simple, engineering.

15 Year-Old Kenyan Prodigy, Richard Turere, Who Created “Lion Lights”

He fitted a series of flashing LED bulbs onto poles around the livestock enclosure, facing outward. The lights were wired to a box with switches and to an old car battery powered by a solar panel. They were designed to flicker on and off intermittently, thus tricking the lions into believing that someone was moving around carrying a flashlight.

The astonishing aspect of this is that Turere installed the whole system by himself, without receiving any training in electronics or engineering.

This is a great video which includes good examples of the value to experimenting, learning and adapting. Iteration is a critical skill when developing solutions. Try out prototypes and learn from what happens. Use that knowledge to develop new solutions or modify the existing solutions and experiment some more. Continue to iterate and improve.

This is another great example of people using their initiative, creativity and engineering talent to create appropriate technology solutions to create solutions that improve their lives. It is great to see how these efforts continue over time, this BBC article follows up on Richard Turere several years after his initial success:

What happened to the boy who chased away the lions?

The Lion Lights system is now in 750 homesteads in Richard’s community and beyond, with the innovator making small tweaks and improvements to each version.

Lion Lights 2.0 costs $200 (£150) to install. Half of the money usually comes from NGOs while the rest is provided by the herder.

This version has 16 different flashing light settings and Richard’s latest update is a homemade wind turbine for days when clouds limit the solar power potential.

But while his idea has travelled, support for Richard as a young innovator and the implementation of his own Lion Lights has stalled in recent years. He thinks Kenya could do more to help young innovators like himself.

“There are many young people in Kenya with brilliant ideas, better even than mine – they just need support,” he says.

They need someone to be there to tell them, “this idea is really nice., let’s develop it to help communities”.

The efforts of so many great young people to create solutions that make the world a better place are inspiring.

Related: Electric WindBeehive Fence Protects Farms from ElephantsAppropriate Technology and Focus on Improving Lives at MITUsing The Building of Robots to Engage Students in Learning

Using Horizontal Polarized Optics to Block Screens

Animated polarizer in front of a computer flat screen

Animated of a polarizer in front of a computer screen (via Wikipedia).


These interesting glasses block LCD/LED screens through horizontal polarized optics. I think this is more an interesting application of science that a useful product but maybe some people actually would like the product.

The video below looks at how IRL Glasses block most TVs (LCD/LED) and some computers (LCD/LED). IRL Glasses do not yet block smartphones or digital billboards (OLED).

Related: App to allow a user to use American Sign Language to interact with AlexaAutonomous Delivery Robots Launched in Europe and USA3D Printing at Home: Today, Challenges and OpportunitiesThe Engineer That Made Your Cat a Photographer

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Saving Lives with Appropriate Technology Health Care Solutions: Treating Infant Pneumonia

How a shampoo bottle is saving young lives, a doctor in Bangladesh has found a simple way to treat infant pneumonia

Last year 920,000 children under the age of five died of pneumonia, making it the leading killer of people in that age group. This figure is falling (in 2011 it was 1.2m), but it still represents 16% of all infant deaths. Such deaths are not, however, evenly distributed. In Bangladesh pneumonia causes 28% of infant mortality.

Dr Chisti says that, as well as saving lives, his device has cut the hospital’s spending on pneumonia treatment by nearly 90%. The materials needed to make his version of a bubble-CPAP ventilator cost a mere $1.25. The device also consumes much less oxygen than a conventional ventilator. In 2013 the hospital spent $30,000 on supplies of the gas. In 2017 it spent $6,000.

Efforts are underway to test this innovation and spread the adoption of this appropriate technology solution to other poor countries. It is wonderful to see engineering innovation making such important improvements in health care around the world.

Related: Appropriate Technology Health Care Solution Could Save 72,000 Lives a Year (low-tech visual exam cut the cervical cancer death rate)Drone Deliveries to Hospitals in Rwanda$1 Device To Give Throat Cancer Patients Their Voice AgainWristband Thermometer Can Save Many Babies’ Lives