Friday, 22 October 2010
Sunday, 10 October 2010
Green Engineering: Self-Cleaning NanoTechnology
Green Engineering: Self-Cleaning NanoTechnology
| | English| লিখেছেন | ৬ comments Sunday, 10 October 2010 |
|
|
Dedicated to David Suzuki, and THRC's Green Technical Textile Knowledge Network Initiative. Nature has nurtured our environment with abundance of resources and green energy. Can we harvest, harness and sustain these free energy to foster innovative solutions to clean our environment? Yes, we can. How? Imagine a green engineering solution to clean air-pollution to foster a sustainable clean environment. Imagine a truly textile substrate, integrated with green nanomaterial, keeps cleaning air and environment to provide us comfort and quality lifestyle that we envision. Plant's chlorophyll, a typical natural photocatalyst, captures sunlight to turn water (H2O) and carbon dioxide (CO2) into oxygen (O2) and glucose. On the contrary in the presence of light and water, photocatalyst nTiO2, creates strong oxidation agent and electronic holes to breakdown the organic matter to CO2 and H2O as shown in figure.. 
Chemical Reactions:
Disinfections by nTiO2 is x3 stronger than Cl2 & x1.5 stronger than O3
Wavelength of light required for Photo-excitation ʎ =Planck’s Constant, h:1240/Band Gap Energy: 3.2eV = 388nm
Research reveals that bacteria, molds and mites inside carpets and air
conditioners can be airborne - dust particles, paints, varnishes and
pressed wood products used in interior decoration, form formaldehyde,
benzene and other hazardous and carcinogenic chemicals as well as
matters produced in human metabolism and ammonia inside toilets have
made the indoor air severely polluted than the outdoor air.
Usually people spend about 80-90% of their time indoors. They are
exposed to polluted indoor air that may cause headaches, dizziness,
irritation, fatigue and even lung cancer and other
malignancies. Scientists have been modifying materials and offering
creative solutions to these challenging problems.
TiO2 Crystal Structures:
Features:
Benefits
Self-Cleaning Mechanism:
Toxic VOC + Light + H2O + TiO2 = Non-Toxic Inorganic Gas + TiO2
Click on the links below for in-depth information. Explore and enjoy!
Green Engineering: Self-Cleaning NanoTechnology
Interesting Links:
Featured Insights:
2010 Self-Cleaning Coatings, P A Carpentier, K D Burgess, WO/210/078649, PCT/CA2010/000009, Jul 15
2010 Extreme Engineered Materials Design, S Islam, Textile, biggani.org, Jul10
2010 Super Strong NanoCrystalline Cellulose Synthesis: Challenges and Opportunities, S Islam, Nanotechnology, biggani.org, Jul 04
2010 Progress and Perspectives in the Carbon Nanotube World, M Endo, AZoNano.com, Jun 23
2009 Nanoparticles Used in Common Household Items Cause Genetic Damage in Mice, Science Daily, Nov 17
2007 Boiactive Silk Proteins as Geotextile Substrates, M Tsukada, S Islam, Y Ishiguro, Textiles & Clothing, Jan-Mar 5-6
2006 Methods and apparatus for spinning spider silk protein, S Islam et al., USP 7,057,023 Jun 6
2005 TiO2 Photocatalysis: A
Historical Overview and Future Prospects, K Hashimoto, H Irie, A
Fujishima, Japanese Journal of Applied Physics, Vol. 44, No. 12,
8269-8285
2005 Value-added Textile Technology, S Islam, Textile Excellence J., Anniversary Issue, Jul. 3(1) 55-56
2005 Photocatalyst technology adds value to fabric, K Tagawa, Fabric Architechture, May
2005 Titanium dioxide photocatalysis: present situation and future approaches, A Fujishima, X Zhang, Elsevier, Feb 2, 750-760
2004 Enhancing Sorption
Properties of Natural Fibrous Protein Substrates. Part I: Absorption
of malodorous gases, M Tsukada, H Katoh, S Islam, N Kasai, Text. J.,
121(6) 48-50
2004 Antibiotic Silk Substrates for Healthcare, M Tsukada, G Shen, S Islam, Text. J. 121(5) 47-49
2003 Process of producing a
titanium oxide-forming solution and a dispersion with crystalline
titanium oxide particles, I Hiromichi, USP 6,602,918, Aug 5
2002 Photocatalytic body and method for making same, I Hiromichi, USP 6,429,169, Aug 6
1999 Suppression of
Surface Recombination on TiO2 Anatase Photocatalysts in Aqueous
Solutions Containing Alcohol, O A Semenikhin, V E Kazarinov, L Jiang, K
Hashimoto, A Fujishima, American Chemical Society, May 06, 3731-3737
Picture Credit: courtesy of medilamp.com
Stay tuned. More to come....
Acknowledgements: TexTek Solutions :: MW Canada Material Innovations.
শফিউল ইসলাম
ইমেইল:
shafiul_i@yahoo.com :: ওয়েবঃ textek.weebly.com :: Canada :: www.linkedin.com/in/shafiul2009
|
|
| সর্বশেষ আপডেট ( Wednesday, 08 February 2012 ) |
Green Engineering: Self-Cleaning NanoTechnology: http://biggani.com/content/view/1431/178/
প্রবচনগুচ্ছ - গোলাম মোস্তফা
১
বুঝে পড়ে দেখিলাম করি তালিকা
সবচেয়ে সুমধুর ছোট শালিকা ।
২
মোটা পণ লালসায় মন ভরোনা
শালী যেথা নেই সেথা বিয়ে করোনা ।
♪ ♫ ♪
প্রবচনগুচ্ছ
গোলাম মোস্তফা
মনোহরপুর
শৈলকুপা
ঝিনাইদহ
Wednesday, 6 October 2010
Rima’s Letter
Mizan Rahman
There
was a letter from home yesterday. It was my niece Rima, daughter of a younger
brother of mine. She is very concerned about this old uncle of hers. Concerned
that I am not taking good care of my health. In her mind everybody is too busy
fussing over the poor health of my wife to pay any attention to mine. So she
feels obligated to write to me from time to time, mostly to admonish me, then
to remind me about all my “do’s” and
“don’ts”. Must drink a glass of freshly squeezed orange juice everyday, must
eat a slice of Jamaican papaya with your breakfast, and a good portion of a
grapefruit. You must never go near that salt shaker, and no oil but the purest
of pure olive oil. And yes, don’t forget to say your prayers everyday, 5 times
a day, and never, ever forget your daily exercises. Quite a taskmaster, this
niece of mine. And she is not even my own daughter! I wonder what kind of
torture I would have to suffer if she were. Would I be able to take so much
motherly admonition from her?
Writing letters
has gone out of fashion these days. It has gone the way telegrams and
‘trunk-calls’ have gone. Everyone sends e-mails or ‘text-messages’. Electronic
device, mostly. Even important documents are no longer put in the mail, they are
either faxed or scan-mailed. It’s the modern age, defined and dominated by
technology. No country, rich or poor, large or small is any exception---the
phenomenon is global. It’s a global village, as the slogan says. That includes
our own country, Bangladesh.
We may not have enough food to eat, but that doesn’t hold us back from owning a
cell phone and/or accessing a computer to send an e-mail to someone we care
for. On paper Bangladesh
is not too far behind the emerging superpowers like India and China. On
paper!
Except these two
children of the low-income brother of mine. As well as the children of a sister
who is equally deprived of many of the niceties of life. They do not have
computers in their house, not even a mobile telephone. Can’t afford one. Essential
food items gobble up most of their take-home earnings. At the end of almost
every month they are forced to take a loan to run the rest of the month, just
to survive. They do not have any disposable income to spend on luxury items
like a computer----yes, computer is a luxury item for them. Just like my
childhood, when we didn’t have running water in our house, nor electricity, nor
telephone, fridge or a radio. What we used to do is come home from school, grab
a cookie or two from my mother’s cookie jar, drink a glass of water, or a glass
of milk if lucky, then run off to play soccer with friends in the neighborhood
field. Then came home, took a cold bath in an uncovered bath area, say my
prayer, ate a simple meal, then got down for homework. My brothers and sisters,
4 or 5 of them, all cramped up at the same table, reading our books as loud as
possible to make sure they are well within the hearing range of our parents. On
the table we had just one dimly lit kerosene lamp to share among all of us. These
will surely sound like horror stories to the children of today’s electronic
age. Nowadays my relatives’ children commute on the family car back and forth
to school. Back home in the afternoon they relax in the TV room with plateful
servings of puris and pakurahs
and jilebis. Perhaps they turn the A/C on and lean back on the soft
sofas for a quick nap. Or pick up the cell to call a friend when they get
bored. Oh, that abominable thing called cellphone, that ubiquitous cell, the
greatest equalizer of modern life! Is there a Bangladeshi family that doesn’t
own at least one cell, I wonder.
Most school
children don’t rush out to the fields as soon as the classes are over, as we
did. Where are the fields anyway? They too have vanished. Like the old typewriter
or the fountain pen or the sewing machine. Besides, whom will they play with?
‘Neighborhood boys’ do not mean quite the same thing as before. The phrase
usually refers to the hoodlums, the goons, the ruffians, or worse. They are
constantly prowling the streets looking for ‘hits’, for ‘preys’. Neighborhoods
are always tense with mortal fear of these ‘neighborhood boys’. People don’t
usually let their children out alone after school. They just sit tight in the
house with shuttered windows and locked doors. Their children play monopoly in
the house, the video games, or just do nothing. I don’t know when they do their
homework, or if they do at all. Many of them, especially the ones from
relatively affluent families go to the coaching classes or to the teachers’
homes. Seems like the good old custom of reading at the top of your voice has
gone out the window. The only thing they still read aloud, and will probably do
till eternity, is the Holy Quran.
Except the family of this brother of mine.
Mainly because they do not have a car---can’t afford one. Rima doesn’t play
video games because she can’t----there are no facilities. Every morning she
takes her meal with plenty of rice and vegetable curry with one or two pieces
of a burbot. Then she goes to the university on a rickshaw. She carries her
books and papers on her lap along with a small brown bag that her mother packs
with a few cookies or a piece of cake for her afternoon snack. At lunch break
her class mates go out in chauffer driven cars to their homes or nearby Chinese
restaurants, while she finds herself a corner in the back of the common room to
gobble up her snack before the other girls get back from their lunch. She is
too proud to let anyone see what is inside her ‘lunch-bag’. In the evening her
nervously waiting mother breathes a sigh of relief when her daughter’s face
appears at the door----one more day has passed without a trouble. No
Bangladeshi mother these days can relax while her 20-yr old daughter is out of
the house. Especially the girls who have to go to schools or colleges on
rickshaws or scooters. They worry all
day until they are back home safely----mostly because of those ‘neighborhood
boys’ roaming the streets looking for easy preys like Rima. These animals will
think nothing of destroying an innocent girl’s life for their own momentary
pleasure. Or to tear off her earlobe to snatch the pair of earrings, or to take
off with whatever little cash she might be carrying in her purse. Slightest
resistance from her could easily result in a knife in the stomach or the blades
of a sharp razor in her throat. These lowly creatures never get caught by the
police, or if they do, get released just as quickly thanks to a telephone call
from one of their powerful godfathers.
My brother
works at a local bank. Manager of a branch office. Monthly salary: seventeen
thousand takas. In my mind I think of 1958 when I first joined the Dept.
of Mathematics as a senior lecturer with a princely salary of 450 takas. Compared
to that my brother should be living like a king. Except that time has changed.
In 1958 ten takas were enough for the daily grocery of a family of 10
adults-----now it takes 500 for a single midsize fish! The biggest price tag is
on the rent—it can easily gobble up close to half of your monthly income. They
live in a tiny 2-bedroom apt. in a dark alley of a lousy area called
Siddeswari. Their apt. is on the 4th floor. The stairs to the apt.
are always in a filthy condition, no lights whatsoever, it’s pitch dark even
before the sun has actually gone down. Could you guess how much they pay for
it? Not one, not two, but as much as seven thousand! Seven thousand for a dark
hole in a rat infested alley! Per month, of course. I had to mention this lest
you thought it’s per year. Before I actually landed in Dhaka
I had all the intention of sharing my time with all my siblings----at least one
night each. But as soon as I entered their apt. I got a real shock---no, it’s
impossible. I can’t stay here, even for a night. Not just the filth and stink, but
a whole army of insects having taken the entire family hostage. Swarms of
mosquitoes milling around me in a blatant attempt at carrying me up to their
den for a communal feast. Admittedly each room had a large window, but
unfortunately they were all closed securely from inside. I wondered, naively,
why on earth they would do that in broad daylight in a 4th floor
apt. where the break-in possibility was almost nonexistent. I got the answer.
The fear was not of the thieves but of the eyes. What eyes, I asked innocently,
like a 12-yr old child. The eyes of an evil character next door, they said. You
can’t open the windows without his dirty eyes prying into your privacy. He will
sing cheap songs from the Hindi movies, make obscene gestures, throw love
letters through the window. Not always, of course, only when Rima is in her
room. In the olden days you could complain to his parents, or to the
neighborhood elders, maybe even to the police. But those days are gone. The
boy, apparently is involved in the politics of Students’ League---- a fearful
band of gangsters who are well-protected by their sponsors upstairs. Today they
are the guardians, they are the neighborhood elders, they are the
police. If Rima’s father is foolish enough to ask for legal protection perhaps
it will be the daughter who will be picked up for questioning. Yes, it
was this very neighborhood where that hapless young man Rubel used to live. For
absolutely no fault of his own he was beaten to death by the police, then the
body cast aside by the street in the dark of night. If it is not the fear of
police it is the fear of acid. Yes, acid, that burns, maims, or kills. Acid is
so callously and regularly used by the spurned lovers bent on taking revenge
(if I can’t have you I’ll make sure nobody will) -----mostly done by the
well-connected student leaders. They will not bat an eyelid to burn a girl’s
face and destroy her entire life in a fraction of a second. Ordinary citizens
are now resigned to their fate. No use calling for help----there’s no help but
the help of God in this godless land. This probably explains why the average
Bangladeshis seem to be much more religious than they ever used to be.
I guess it is
common knowledge by now how a young girl called Bnadhan was disrobed publicly
by a mob on the open fields of the University
of Dhaka. It happened
right after the day I arrived in Dhaka. It was
the front page news in the local newspapers complete with gory photographs of
the poor girl, a very juicy, saucy piece of news that everybody loves to read
and reads to hate, that helps raise the sale of the paper and provides ample
ammunition to the gossip mongers. The national leaders were quick to come out with
statements of condemnation for the unfortunate incident. The Home Minister made
a promise to apprehend the culprits as soon as possible and bring them to
justice. Even the uniformed police came forward with their own promise of not
resting until the criminals are arrested. The University President joined the
chorus of condemnation, expressing “deep regret” for this dastardly act having
happened on the premises of his venerable institution. He didn’t forget,
however, to add a conciliatory remark to the student body, that he would never
believe that the guilty boys could be students from his University. Too
bad that the same day the news broke out that one of the perpetrators of the
despicable act was none other than a prominent student leader, very
well-connected with the high and mighty, and of
the higher echelon of the ruling party, and was indeed from his venerable
campus. Apparently he was identified by the victim herself. But nobody in
his/her right mind believes that the young man will ever be brought to justice,
let alone punished for his crime. No one in Bangladesh today has the guts to
ask for punishment of a student leader, no matter what the crime is. I couldn’t
find a single person who really believed that the law would be able to, or even
try to, touch the scoundrel. Money and political influence can buy anything
today. Law and Order is just a slogan that is routine bread and butter of every
Opposition Party. Law exists there not to be obeyed but to be broken. And they
are broken mostly by the law-makers themselves. Cabinet, Legislative bodies,
Ministers, Bureaucrats, Police---- there’s no exception. People laugh when you
combine the two words: Law and Order. What a joke, they say. Or they think it’s
a quote from a prepared speech.
Such is the
sickening atmosphere of cynicism in my country today.
The sick game of
pulling a girl’s dress has been such an old culture in our society that I get
surprised when someone expresses outrage and revulsion when something like that
does actually happen----our young men have always had a strange fascination
with this game. Young women have always been an object of amusement and
pleasure for the men folk. No matter how much we idolize them through poetry, no
matter how passionately we profess our solidarity with their demands for equal
rights, in our eyes fundamentally they remain little more than sex
objects----something to stoke our fantasies. In the olden days this hidden
desire would find expression in a more civilized and subtle manner, but now it
is all so open, and often so brazenly aggressive. Wasn’t only the last year
when a bunch of policemen got hold of a young girl and undressed her publicly in broad daylight? There were the
usual herd of eager correspondents from the tabloids and newspapers salivating
on the delicious scene and taking pictures for the morning editions, while the
greedy eyes of a crowd of onlookers swallowed up every tiny bit of her bare
flesh. I don’t know why such disgusting things are happening so regularly these
days. Could it be because of a twisted sense of freedom and openness derived
from the nation’s political independence?
I talked to a number of well-educated people about this unpleasant
incident and asked for their opinion. Would you believe no one was willing to
put the blame on those offending boys, rather they quite emphatically placed
the blame on the victim for failing to exercise prudence before showing up in a
crowd like that in less than ‘an appropriately modest’ attire. According to
them she asked for trouble by simply being there. So she got what she
deserved----no point complaining about it now. The comments came from no less
than the people who live in fashionable houses in exclusive areas of Banani,
Gulshan and Baridhara, whose grown children have left home for higher education
in prestigious colleges of Europe and America. And, women outnumbered men
in their vocal denunciation of the “outrageous” behavior of that “shameless”
girl in the streets. These are the ladies with highest degrees from the
country’s best colleges. So why should it surprise you if the culture of vulgar
amusement and entertainment is perpetuated till the end of time in that
godforsaken land of ours?
There is no
denying that women have a great deal more opportunity these days to get an
education in Bangladesh
compared to what it used to be in the olden days. Not just the girls from
relatively well-off families but from the utterly poor ones also. One of the
housemaids in the household of a sister of mine apparently has a daughter doing
postgraduate work in Statistics. In my own native village I saw the daughters
of my cousins no longer thrashing paddy on the wooden pedals or picking
cucumbers from the fields, rather riding the rickshaws every morning to their
classes in the nearby college. They become doctors, engineers, teachers,
lawyers, or nurses. Some even make careers as architects, pharmacists,
physiotherapists and hairdressers. So one can indeed claim, at least on paper,
that the country has moved forward in very impressive ways compared to what it
used to be in the pre-independence time.
And yet, I
couldn’t find a single girl riding a bike on the street, or even driving a car.
Not but a handful of women without a head cover, called hijab, some even
with full nikab, covering their whole bodies. These so-called modesty
dresses for Muslim women that have become such a common sight in the streets of
Dhaka nowadays were not quite as common in our
days, which I find very curious and puzzling. In my student days in Dhaka I didn’t even know the meaning of the word hijab.
It simply didn’t exist in our vocabulary. It is not a Bengali word. Yet,
today, the word is part of our common vocabulary. In my time I never heard of a
woman being flogged or stoned on charges of adultery or other sex-related
offenses, but now the deadly fatwa is always ready to strike the poor
woman. One fatwa is enough to destroy a woman’s life for good-----she
will have nowhere to go, not even her parent’s home. In the bygone days the
girls wouldn’t usually go for higher degrees ( because there used to be a
widespread social taboo against Muslim women’s higher education, most of them
being married off at 16 or 17), but they wouldn’t be victims of acid-throwing
either. Compared to the times before independence the incidence of rape and
abduction has increased manifold, dowry murder has become a common thing.
Daughters had never been a major concern for Bangladeshi Muslim parents, but
now they are. A daughter usually means dowry, often unbearably large dowry. As
a result the number of unmarried daughters has greatly increased in Muslim
families these days, especially those with little means to eke out a half
decent living. The chauffer of my sister’s car had a newborn baby girl. As I
was trying to congratulate him on the happy news he sighed, and said: “ Sir,
what’s the point of getting congratulations? What I need is fifty thousand takas.
If I could keep that amount of money in the bank then I could get the girl
married. “
I had the good
fortune of being a dinner guest of a highly educated and culturally accomplished
middle class family at their residence in a densely populated neighborhood of Dhaka. They were 2 older brothers and 4 sisters. The
sisters were all very good-looking, well-educated, and well-mannered. Quite
attractive, I would say. And yet they were all unmarried----all but one having
already crossed the age of 30. And there didn’t seem to be a hopeful sign that
the situation would change anytime soon. Why?
First, even though their father was a senior bureaucrat in his working
days, was now retired. More importantly, he had one serious flaw! He was an
honest officer! Honesty is indeed a character flaw, a weakness, in Bangladeshi
society these days. Which explains why he couldn’t acquire large chunks of
property in posh areas of Dhaka as most other
officers, even the ones at lower ranks than him, have been able to do. Which is why at retirement he had to be
content with a modest home in a rundown building in a decrepit part of the
town. Today it is his daughters who are paying the price of his “clean” living
and his unwavering principle of integrity.
There is no way
I can guarantee that my brother himself has clean hands, as far as corruption
is concerned. However, when I see that after 25 years of active service in a
major bank of Dhaka he still doesn’t own a car, nor has a glittering home in a
fashionable area of the city, I feel reasonably confident that it was his
deliberate choice to stay away from that slippery path that so many of his
contemporaries seem unable to avoid. Maybe this is what explains this pathetic
state of his life in a filthy area with dark alleys where the sun never seems
to rise. Maybe this is why his only daughter, his princess, the pearl of his
eye, has to take the risky way every day taking a rickshaw to attend her
classes at the university. And his only son has no choice but walk every day to
his not-too-close school.
I feel real bad
for Rima. Foolishly I asked her if she had a dream. Of course she had. How
silly of me to even ask. Every child has a dream. Especially a child from an
impoverished family. Dreams are the only escape they have from the miseries of
life, their only bit of reprieve. Nobody can take that away from them---it is
their birthright. In my youth I too had a lot of dreams which I never shared
with anyone----they were strictly my own property, my only property. I’m sure
my 4 younger sisters had their own dreams which they dared not share with
anybody for fear of being laughed away. But I always knew what they wanted from
life. They just wanted a normal life, a life where they would have a choice, choice
to pursue their goals, to get the highest degree from the best university in
town, and then, maybe, just maybe, meet their prince charming on the way, to be
desired, adored and cherished. If not a
prince at least a top officer in the government. None of those lofty dreams
really came true in their life, they never really do, so they had to settle for
whatever fate had ordained for them. In countries like ours’, girls’ dreams
almost never ever come true. Yet dreams are important. They help deal with the daily
grind and drudgeries of life. They are a source of hope, light and joy.
Rima wrote: “
You know uncle, I was bit upset with you that you didn’t spend a single night
at our home. In fact I was quite sulky. But not anymore. The world you live in has
completely different set of rules, and norms, I know. But sometimes, at weak
moments, I let myself forget that. That’s why I sulk, I feel sad. Please don’t
mind, uncle. The few days you were in Dhaka
somehow felt different, as if my life had changed a little. I felt as if there
was a bit of fresh breeze in the air. But then you went away. Without your
knowing that breeze also went with you. Our life is now back to normal.
Maybe this is
her dream---a dream for a bit of fresh air. Perhaps she doesn’t fancy a prince
charming from the fairy tales like my sisters used to, nor does she dare to
hope for a top civil servant. Maybe all she wants is to be able to keep her
windows open at all times. And to be able to let her wet hair hang lazily to
her knees in the open space of the roof, to soak up the afternoon sun in cold
wintry days, to leisurely button up her blouse with no concern for anyone
stealing a look, or to sing away her favorite songs in great abandon. Or could
it be that her only dream is to escape to the fairy land called North America, like her uncle had done? Perhaps all she dreams about is to be able to
go a place where there are no strikes, no coaching classes, no postponing the
exams, no murders, or purse snatching or mugging or brazen attempt at disrobing
a fun-loving innocent girl on the new year’s eve. Maybe she even dreams to ride
a bike like the western girls do, to swim in a pool, to buy her favorite nuts
from the street vendor and start eating while walking with friends.
I do not know if
I really understood the meaning of Rima’s letter. Perhaps not. Perhaps all she
was trying to tell me: uncle, I can’t breathe anymore. Would you please take me
away from this hell?
Ottawa,
October
6,’10
( Translated from the author’s Bengali article by the
same title written and published in February, 2,000).
মীজান রহমান,
Mizan Rahman
Subscribe to:
Posts (Atom)