Ever wonder what actually the jobscope of an engineer? Well, hopefully this answer could enlighten your curiosity...
2 December 2013
30 November 2013
"Do you ever feel like a plastic bag
Drifting through the wind, wanting to start again?"
Remember that lyrics in Firework by Katy Perry? Now, plastic bags can definitely have a chance to start again - not through a typical recycle process, but through an upcycle instead. Much valuable upcycle, as the research done at the University of Adelaide has proven the high possibility of non-biodegradable plastic bags that we churned out daily into the garbage bin could be synthesized into carbon nanotubes membranes. No longer that we wanna rely on using natural gas as the precursor material in producing CNT, now plastic bags itself could be re-purposed into a new usage due to the similarity of carbon network that made up their main exoskeleton.
CNTs membranes are an excellent platform for such applications as water desalination and purification, gas and pervaporation separations, nanofiltration of biological mixtures, transdermal drug delivery, ultra-sensitive sensing and energy storage [Altalhi et al, 2013]. Back there in the Middle East, membrane filtration is highly utilized for treating seawater into domestic use water by removing high salt content in the former (which is also called reverse osmosis). Not only that, the use of membrane in purification of gas is also abundant through the different selectivity and/or pores characteristic that will filter out the sizes hence producing lean gas output.
CNT is a go-to technology nowadays as the structure of the sorbing component resembles a 'tube' that will increase the surface area ratio with a given mass. The height of the tubes as well as its diameter could be tailor-made to suit various application. That is why CNT is preferably called the 'designer adsorbent' when it comes to adsorption process, since we can alter its dimensions accordingly by changing the synthesis process parameters.
With this new technology done at University of Adelaide, a noble direction in finding a usage of discarded plastic bags is an excellent mean of waste-to-wealth ethos. Somehow it abide the balance in the sustainability triangle for not only saving the environment - especially in term of polluting the surrounding community with smell and possible health hazard, and taking up land space; but it could provide a new job opportunity for the surrounding community too should a new plant to be constructed, as well as provide income flow.
My only problem with this new upcycle method of plastic bag-to-CNT is one: how can we make it even more greener? Coz looking at the temperature alone for the synthesis, 850 - 900oC is very high; hence related to the higher consumption of energy (thermal energy). Perhaps in the near future, improvements could be made into modifying the process parameters that would bring it down to STP (1 atm, 25oC). A definite challenge, yes.
Also, it will be interesting to see the possible cost of synthesis since being an engineer we always looking into dollar and cents after all. How would this synthesis stand side by side in term of saving the environment effort vs. cost of production of CNT via plastic bags vs. total energy usage vs. carbon footprint? If one does not agree to each other, how can we further optimize; so that in the end the vying public, the stakeholders, the chemists, the environmentalists, the chemical engineers would resoundingly agree on one thing : YES, THIS IS A GOOD TECHNOLOGY.
That, we'll see what the future of this technology will hold. In the mean time, this method is a new niche area to be explored.
[Source: TCE, November 2013]
(picture used without permission from the journal. original copy of the journal : CLICK)
1 October 2013
Being involved with Air Pollution Engineering since 2011 made me aware on the importance of the status of the surrounding. The temperature, the pressure, the wind speed and its direction, are all vital not only in predicting the possibility of weather condition for that particular day or period, but also in forecasting the mitigation or control on the probability of air pollution to occur. The state of the environment after all is all related to fluid mechanics. Since fluid mechanics (i.e. the combination of fluid static and fluid dynamics) affect the flow of the air and the air pollutants such as dispersed solids and liquids in the continuum of gases (fluid medium), therefore they're very affected with the changes of weather.
Knowing the condition of a particular day is the most essential to an air pollution expert or an environmental engineer. Due to the burst of iPhone/Android apps in the market, it's very useful if the information could be reached right at a touch of the finger. One of my favorite app related to the weather forecast is InstaWeather. Not only that it's the fun way to share through Instagram or any other social media, it's very useful coz some of the 'filter' in the app contains vital information such as:
- Temperature forecast. It shows the highest and lowest temperature, either for that particular day or a week. This gives an information on the chances for any air pollutants to be in much vaporized state or more in its liquid dispersion states in the air - since the physical states of matters always related to high/low temperature (and pressure too) as it moves along the phase diagram such as in pressure-temperature (PT), pressure-volume (PV) and temperature-volume (TV) diagrams.
- Precipitation chance - the possibility of rain to occur. If you're planning for an outdoor activity, you wanna avoid any rain to dampen your mood. Hence, by having this prediction on the possibility of downpour, it least it could make you much prepared. Again, you'll never know coz it's in God's hands; like what happen to me when I lived in London. One minute it was hot and sunny sky, the next minute you get a heavy downpour despite the weather forecast doesn't say so. Precipitation chance is also important to an environmental engineer as it could allow him/her to plan for seeding of rain such as in the minimization of smog due to haze, just like what happen in the midyear of 2013 here.
- Humidity index - vital for the one who design dehumidifier to predict the performance of their product. Also, it could be used to predict how long your clothes be dried in the open sun. If the humidity is high, the longer it takes to dry compared to less humidity; since the drying rate is depending on the state of liquid vapor in the ambient air. But then again, this is one of the factors affecting other than temperature and wind speed as well.
- Wind speed. For an air pollution or environmental engineer, wind speed is important to determine the time taken for air pollutants to travel from a source point to another. Using either fixed box model or Gaussian plume model, wind speed is the main criteria included in the calculation of the concentration being measured. The higher the number, the higher the chance for it to be transferred, thus an environmental engineer should know where and how the mitigation could be carried out for safety purposes.
- Wind direction. Again, this one also relates to point above on predicting the concentration of pollutants. If wind speed forecasted the travelling period of the air pollutants, wind direction will predict where it's heading. One case study I did was last June when I predicted that the haze which occurs at Selangor will travel to the vicinity of Perak (Ipoh, to be exact) would happen on the weekend of 15/06/2013 (if I can recall). How did I predict that? It's after seeing the wind direction that suddenly changes from North West in the previous weeks to South East on that Saturday. Not long after, it was during the afternoon I can smell the scents of burning smoke though at a very low concentration level. And the day after, the ambient turned darker indicating haze is already occurred (which lasted for a couple of days here). But it gets better as the wind direction changes again, coupled that with raining that occurred at the same time.
- State of the weather - sunny, very cloudy, partly cloudy, etc.
In short, despite InstaWeather is a great app for fun that you can share it through social media, it could be very helpful for an environmental or air pollution engineer to use for their job per se. The information it shows could always be used as a guide in mitigation of air pollution or prediction for the safety purposes.
6 September 2013
Solving a problem numerically is only half of the thrill becoming an engineer (or scientist). But the real challenge is actually to make a good judgement and a good reasoning on why it happens that way, why we choose the solution route and why that is the best one we've selected among the others existed.
A good engineering judgement always come from two things: a good grasp on technical knowledge + previous experiences.