Chemistry Involved in Car Airbags and Fire Extinguishers

                                                                                                                      - Shiv K Sharma

Advancements in chemistry have also led to a better life for human beings. The chemistry advancements have led to better sanitation and hygiene technologies. Moreover, chemistry provides a range of important benefits in home and personal care products, clothing and sports equipment, automobiles, and electronics. As an example, chlorination disinfects drinking water. This chemical process kills waterborne bacteria and viruses that cause up to 3-4 million deaths per year. Thanks to innovations in chemistry, automobiles can be manufactured to be lightweight and more fuel efficient, building materials are more durable and resilient, and electronics like cell phones, computers, and televisions have enhanced functionality to meet the technology needs of today’s consumers.

Among different discoveries that save millions of lives every year, I am going to talk about the chemistry of two important discoveries that have equal contributions to saving human lives. Firstly, the chemistry of car airbags and secondly, the fire extinguisher.

Chemistry of Car Airbags

The airbag specifically for automobile use is credited independently to the American engineer John W. Hetrick, who filed for an airbag patent on 5 August 1952, which was granted #2,649,311 by the United States Patent Office on 18 August 1953. It is said that the concept of airbags came into the mind of John Hetrick when his family had a car accident. He was out on a Sunday drive with his wife and young daughter in 1952. Hetrick swung his car into a ditch in order to avoid a deer, and he and his wife flung their hands up to protect their daughter. While driving back home, he had an idea of an object coming out of the dashboard to soften the collision. 

                         

After these many years, there have been significant improvements in car airbags. However, the main chemical Sodium azide (NaN₃) has not been changed. Sodium azide is a rapidly acting, potentially deadly chemical that exists as an odorless white solid. An electrical charge triggered by automobile impact causes sodium azide to explode and convert to nitrogen gas inside the airbag. The reaction is as follows:

                                                                                2NaN₃ (s) -->  2Na (s) + 3 N₂ (g)

The problem, however, is that the reaction also forms sodium metal which reacts with moisture to generate sodium hydroxide, a highly corrosive substance. A burst airbag could wreak havoc. Chemical ingenuity, however, came to the fore. If potassium nitrate and silicon dioxide were also included with the sodium azide, the only products that would form in addition to nitrogen would be potassium silicate and sodium silicate. Both of these are inert, harmless substances.

 Chemistry of Fire Extinguishers

A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. When talking about fire extinguishers, most people think of the device produces carbon dioxide gas that helps in extinguishing the fire. However, there are many types of fire extinguishers. The main types are water, foam, CO₂, powder, water mist, and wet chemicals. Each of the different types of fire extinguisher is suitable for different fire classes. It is important that we purchase the right fire extinguisher for our specific needs.

 There is also different chemistry involved in these different fire extinguishers. Today, I will talk about the chemistry of a foam fire extinguisher.

The foam fire extinguishers use the foam to cover the whole fire and smother it, taking away the air so the fire cannot keep on burning. It is made of diethylene glycol monobutyl ether, 1-propanol, and hexylene glycol. The aqueous film-forming foam (AFFF) is used for solid and regular fuels and also liquid fires like gasoline faster and without flashback. When we pull the pin, it discharges the fire extinguisher and then we pull the trigger which depresses the button releasing the extinguishing agent. The foam is in a liquid form, that is clear with a light straw color, with a mild sweet odor, and has a pH of 7.0-8.5. It is completely soluble in water, not flammable, non-explosive, and not an oxidizer. It is less vapor dense than air and has about the same density as water.

When you pull the lever of the fire extinguisher to fire the foam onto a fire, there releases carbon dioxide which then replaces all of the foam within the bottle. This is an example of a single replacement reaction. Then the foam is next where chemistry is used. It is aqueous film-forming foam and it needs a chemical reaction between water, fluoro tensides, and other various chemicals to create a firefighting foam. A carbon-based fire has an equation of:

                                                                              CH₄  + 2O₂ --> CO₂ + 2H₂O

which then the foam puts out the fire by smothering it or basically taking away the oxygen from the equation.

References

1. https://www.consumernotice.org/environmental/afff/

2. https://www.chemistryislife.com/the-chemistry-of-a-fire-extinguisher

3. https://www.mcgill.ca/oss/article/technology/fascinating-chemistry-airbags

 

 

My Experiences as a Chemistry Teacher in Nepal and the USA

    

    I had the privilege to teach chemistry at a private college in Nepal for two years and here in the USA, I have been teaching for almost three years to undergraduate students. If you ask me which, did you like, I will say- each of these education systems both American as well Nepalese have their own strengths and weaknesses. An education system is regarded best which is responsible for redefining a human being into some talented persona who succeeds in accomplishing his/her dreams.   There are many differences between the United States education system and the Nepalese education system. Of these differences, three aspects are the most important ones. First, in Nepal, the poor’s have fewer education opportunities than the rich. This is in contrast to the United States, where even the poor can get a good education from a good school. Second, the United States has the best technology to help students in their courses. And third, there exists a huge difference related to job placement and career opportunities for students.

    Before talking about the education system in both countries, let me tell my experiences of teaching chemistry in Nepal and the United States of America. I started to teach chemistry for 10 + 2 students (college students) in Nepal after completing my master’ Degree in Chemistry. The classes used to quite a descent – around 35 to 40 students although the public college have a higher number of students. The students demand notes in the class. So, most of the time is elapsed in writing the note in the class. First, I used to describe the topic with examples on the whiteboard for 15 minutes (say) and then asked students to begin writing. Students keep on writing as I go on speaking about the topic. The college used to give the responsibility of teaching a few chapters instead of the whole course. This is something I did not like. The department chair used to prepare the syllabus and divide the teaching load of different chapters among the faculties. The exams were conducted for all subjects at a specific time. The teaching faculty used to be asked to submit the list of questions from the topic that they taught, and the department chair used to finalize which questions are to be included in the question paper. In the USA, faculties are given a full course to teach. The faculties prepare their own syllabus and decide the exam dates at their own discretion.  After my Ph.D., and short postdoc training, I started teaching at a university. I use PowerPoints as well as some other technological tools like  document camera, clickers, etc. The faculties and students are provided access to the online course management system like Blackboard, Canvas, etc. These tools enhance the teaching power and the student's learning experience, saving more time and effort, and allowing greater focus on other priorities. Further, students always know where they stand in their course because the Gradebook in Canvas or Blackboard is always available. The technological tools that I mentioned come with certain costs and certainly the students in Nepal can not afford to. This affects their learning ability. Nevertheless, in my experience, I have found many students in Nepal being sincere and polite with their teachers. In the USA, the students are given more privileges so, they do not afraid to speak with their teachers. I always like to treat the students as friends. The American students are little forward in his matter.

    The position of the teacher in terms of social status differs massively in both countries. The teacher is given a lot of respect for the profession by the people in Nepal although it is declining in recent years. This is mainly due to the rich cultural heritage that has revered the teacher as ‘Guru’. It is not similar in term of the US society. The American students especially in higher education call their teacher or principal investigator (PI) by their first name. In Nepal, we never imagine calling a teacher with his or her first name!

    In the United States, the rich and poor both have equal opportunities to be educated. They receive many benefits, for example, computers, libraries, transportation, etc. On another hand in Nepal, only rich students get higher education, poor student parents can’t afford their children. Rich parents’ children received many benefits and higher education than the poor do. In the United States, the poor student gets more federal aid from the government, and honor students get more scholarship from their schools. In Nepal, there is no such thing as called scholarship for poor students, although circumstances are being changed because of governmental initiations. In Nepal, it cost lots of tuition fees. Only rich people have more money to enroll their children in school.

    In the United States, there are billions of resources for students to learn through computers. Students have easy methods to submit their work through computers, teachers, and students both save lots of time. On the other hand in Nepal, we only have books to learn, we don’t have social media and other resources in use but some changes have been seen after the Covid-19 pandemic. We do all of our work through notebook paper. Students have to take exams through notebooks and students never get knowledge from outside of the world. In the pandemic, where students were abstained from going to school/college, the US schools and universities quickly moved to remote teaching. However, in Nepal, the schools were completely closed and there was no remote teaching as well. This is because students don't have computers at all.

    In the United State, after students finished their education, they have lots of opportunities for jobs. They get offers from different companies. In Nepal, the job is not secured after passing certain courses. This is because the learning process does not overlap with the job market.

    Another important aspect is the evaluation of teachers and courses. In Nepal, especially in higher education, the professors are not evaluated at all. Once they are recruited, their job gets solidified. I have experienced some teachers who used their 15 years old notebook (quite yellowish in look with the age) and never thought of improving their style of teaching. Private college teachers are evaluated while they are being appointed. After that, they never get evaluated by the students. Ensuring teacher quality with a robust, fair, research-based, and well-implemented evaluation system can strengthen the workforce and improve the quality of education. However, in the USA, teachers are evaluated by their students every semester. This compels the teachers to improve themselves.

    Let’s try to compare the education system in Nepal and the USA. The education system in Nepal comprises of pre-primary (kindergarten), primary (1^st  to 5^th  grades), lower-secondary (6^th  to 8^th  grades), secondary (9^th  to 10^th  grades), and higher secondary education (11^th  and12th  grades). Soon after 12^th  grade one can directly join any professional course of choice which means the lesser period of study to become a professional and an earlier job.

    The school education pattern in the USA is divided into three levels, viz the elementary school (kindergarten through fifth grade), the middle school (6^th  to 8^th  grade), and high school (9^th  to 12^th  grade). Once the kid finishes high school, then he or she can enroll for bachelor courses of choice in College and then later join professional courses in Universities which means a longer time of study period to become a professional. The number of students per class is much higher in Nepalese schools. Uniforms are given high priority and adhered to strictly as compared with the US where most schools do not have uniforms and dress codes are very flexible.

     In Nepal, the test basically examines the memorizing power of a student and focuses less on critical thinking power. Even in lower classes, there are formal exams. The exam period is a very stressful period for students as well as parents. The exam dates will be declared well ahead of time and all other activities in the school will be planned around it. During exam season, parents usually cancel all other activities and focus only on creating a study environment for children.
In most cases, the kids who can memorize the study material can score higher marks in Nepal. The ability to think and be creative is mostly not given the recognition it deserves.    

    Creative students score higher in the USA. In lower grades, exams are usually a part of normal teaching and so kids do not usually sit and read for days before they take a test. This is different in higher classes where students prepare for tests earlier, though not so stressful.

The Nepalese education system places a lot of emphasis on rote learning material. Students focus on absorbing as much knowledge as they can. Consequently, students do well in quantitative subjects. However, knowledge is treated as facts and immutable truths rather than ideas to be assessed critically, so young Nepali students don’t do as well in “soft” subjects and are generally poor at critical or independent thinking. Schools for the most part ignore personality development and social skills.

    The American system swings in the opposite direction with a greater emphasis on soft skills and creating a more rounded competitive individual with broader cross-subject knowledge but then weaker in specific subject areas than Nepali counterparts of the same grade. In Nepal, how well we perform in the midterm or final exam decides our grades. Assignments, quizzes, daily classwork/homework, etc. do not hold comparatively much weight in relation to final grades unlike in the USA, though the situation is changing a lot now.

 

Conclusion

    Overall education in Nepal is more about memorizing with study materials, more about academic performance, giving utmost respect to teachers, and scoring in final exams.  Academic excellence achieves more preference than sports or another overall achievement though, with recent modifications which claim to be global concepts, situations are definitely changing. The overall education system in the USA is about learning, preparing children to explore and understand concepts, about learning the concept not only through books but by actually learning through practical’s, not about stressing kids on written exams, not solely about academic competitiveness, about learning in small numbers and more about the day-to-day practical evaluation of the child.

    There are some similarities between Nepalese education and US education.  Both have well-qualified teachers, impart quality education based on modern science and technology, have concepts of private and public schools, properly tailored curriculum as per regular standards, and aim in upbringing qualified professionals for the society.

    
    I personally feel that there are some areas for improvement. In Nepal, there is rigidity where the student has to study all the subjects in the schooling period. There is no chance to skip these subjects. Extracurricular activities and physical education are not given much priority in Nepal. In higher education, students should be introduced to the research. The government should allocate sufficient funds to run the labs by the faculty members. In spite of all this, the works done by Mahabir Pun (established National Innovation Center) and some other scientists who have returned to Nepal from abroad have lite a light of hope in recent years!

This article got published in Nepal's number 1 online newspaper (19th Feb. 2022):

https://english.onlinekhabar.com/education-system-nepal-us-teacher.html

Also in the Nepalese Association of Florida (NAF) quarterly newspaper Indreni:

https://floridanepalese.org/wp-content/uploads/2022/02/NAF-Newsletter-Design-2022.pdf?fbclid=IwAR1evLzBjM3USqT4wopNS0Pkj-Bes9CCqFSeRVgEoUljv123hy5pXZPLbyQ

Writing on Paper than on Tablet or Smartphone Enhances Brain Activity

            Many of us left handwriting behind the day we finished school and stopped taking longhand notes as students. While using a personal computer or tablet is the preferred method of writing for most professional writers, many novelists choose to handwrite at different creative stages of the creative writing process. If you’re getting started writing a novel, it’s worth considering whether working longhand or on a computer is more conducive to your creative process.

                                                                  

            A recent study of a Japanese university students and recent graduates has revealed that writing on physical paper can lead to more brain activity when remembering the information an hour later. Researchers say that the complex, spatial and tactile information associated with writing by hand on physical paper is likely what leads to improved memory. Actually, the paper is more advanced and useful compared to electronic documents because paper contains more one-of-a-kind information for stronger memory recall," said Professor Kuniyoshi L. Sakai, a neuroscientist at the University of Tokyo and the corresponding author of the research recently published in Frontiers in Behavioral Neuroscience. The research was completed with collaborators from the NTT Data Institute of Management Consulting.

            Contrary to the popular belief that digital tools increase efficiency, volunteers who used paper completed the note-taking task about 25% faster than those who used digital tablets or smartphones. Although volunteers wrote by hand both with pen and paper or stylus and digital tablet, researchers say paper notebooks contain more complex spatial information than digital paper. Physical paper allows for tangible permanence, irregular strokes, and uneven shape, like folded corners. In contrast, digital paper is uniform, has no fixed position when scrolling, and disappears when you close the app.

What was the study based on?

            In the study, a total of 48 volunteers read a fictional conversation between characters discussing their plans for two months in the near future, including 14 different class times, assignment due dates and personal appointments. Researchers performed pre-test analyses to ensure that the volunteers, all 18-29 years old and recruited from university campuses or NTT offices, were equally sorted into three groups based on memory skills, personal preference for digital or analog methods, gender, age and other aspects.

            Volunteers then recorded the fictional schedule using a paper datebook and pen, a calendar app on a digital tablet and a stylus, or a calendar app on a large smartphone and a touch-screen keyboard. There was no time limit and volunteers were asked to record the fictional events in the same way as they would for their real-life schedules, without spending extra time to memorize the schedule. After one hour, including a break and an interference task to distract them from thinking about the calendar, volunteers answered a range of simple (When is the assignment due?) and complex (Which is the earlier due date for the assignments?) multiple-choice questions to test their memory of the schedule. While they completed the test, volunteers were inside a magnetic resonance imaging (MRI) scanner, which measures blood flow around the brain. This is a technique called functional MRI (fMRI), and increased blood flow observed in a specific region of the brain is a sign of increased neuronal activity in that area.

            Participants who used a paper datebook filled in the calendar within about 11 minutes. Tablet users took 14 minutes and smartphone users took about 16 minutes. Volunteers who used analog methods in their personal life were just as slow at using the devices as volunteers who regularly use digital tools, so researchers are confident that the difference in speed was related to memorization or associated encoding in the brain, not just differences in the habitual use of the tools.

            Volunteers who used analog methods scored better than other volunteers only on simple test questions. However, researchers say that the brain activation data revealed significant differences. Volunteers who used paper had more brain activity in areas associated with language, imaginary visualization, and in the hippocampus—an area known to be important for memory and navigation. Researchers say that the activation of the hippocampus indicates that analog methods contain richer spatial details that can be recalled and navigated in the mind's eye.

What is the researcher’s recommendation?

            Although the above-mentioned research focused on learning and memorization, the researchers encourage using paper for creative pursuits as well. They said "It is reasonable that one's creativity will likely become more fruitful if prior knowledge is stored with stronger learning and more precisely retrieved from memory. For art, composing music, or other creative works, I would emphasize the use of paper instead of digital methods".

Benefits of Writing by Hand

            Taking notes longhand has definite benefits, and it can be worthwhile for young writers to work with pen and paper, especially in the early stages of a project. Jotting thoughts down on a pad or in a journal can help you overcome writer’s block and develop a more tactile relationship with your story ideas. Some of the benefits of handwriting include:

1.      Writing by hand is useful for visual learners. Writing longhand notes gives you the graphic freedom to easily sketch an infographic, word web, or another non-traditional layout to put your thoughts down and visualize connections.

2.      Writing by hand boosts the learning process. Psychological science research conducted by researcher Daniel Oppenheimer at the University of California shows that handwritten notes help with memory and recall. Oppenheimer’s study shows that areas of the brain associated with recall and comprehension are more engaged when students write notes with a pen and paper.

3.      Writing by hand can be artful. Many people choose handwritten notes over computer notes simply because they prefer the aesthetic. If you have good penmanship or are skilled at cursive and calligraphy, handwriting notes can give you an outlet to practice a hobby while also working on a creative endeavor. All you need are a simple writing implement and a piece of paper, but many people also choose to work with fancy paper and a fountain pen.

4.      Writing by hand helps you avoid distractions. Technology can be an incredibly time-consuming and distracting part of our lives as writers. Writing fiction requires focus and shutting out distractions is an obstacle for many professional writers. Writing longhand away from your smartphone, tablet, or computer can help you focus on actual writing with pen and paper instead of with a keyboard or stylus.

 

 References:

1.      Frontiers in Behavioral Neuroscience.

2.      Medicalxpress.com

3.      Masterclass.com