Why 37 C 80% rH feels far worse than 37 C 40%

"The heat of vaporization of water is the highest known. The heat of vaporization is defined as the amount of heat needed to turn 1 g of a liquid into a vapor, without a rise in the temperature of the liquid. This term is not in the list of definitions given by Weast (1964), so the definition comes from Webster's New World Dictionary of the American Language (1959). The units are cal/gram and values for the heat of vaporization of water at different temperatures are given in Table 3.1. The heat of vaporization is a latent heat. Latent comes from the Latin latere, which means to lie hidden or concealed. Latent heat is the additional heat required to change the state of a substance from solid to liquid at its melting point, or from liquid to gas at its boiling point, after the temperature of the substance has reached either of these points. Note that a latent heat is associated with no change in temperature, but a change of state. Because of the high heat of vaporization, evaporation of water has a pronounced cooling effect and condensation has a warming effect (Kramer, 1983, p. 8)."

The above is standard University Physics. We live in the equatorial or tropics where it is hot and wet most of the year. This year for the El Nino, we are experiencing searingly hot days interspersed with some rainfall. On the searingly hot days, we in the tropics seem to feel that we are under some heavy 'cloud'. That feeling is the humidity in the air. Our bodies are magnificent machines which have the ability to moderate and keep ourselves relatively hot or cold when the temperature changes - but up to a certain extent only.

So my post title is this, why does 37 C and 80% which is very humid feel so much worse than in the temperate countries where the humidity is much less ?

The answer is because, when it is hot, our bodies will sweat naturally, and since sweat is 90% water, it will stay on our body. The fact that water evaporates, because there is heat needed - which is from the body - to make it change to vapour without any drastic change of the external temperature. 

So, when that happens, a loss of heat or energy from our bodies translates to a cooling effect when water evaporates from our skin. This is presumed so, WHEN the air is dry. Hence, the feeling is that there is some cooling, even at 37 C.

However, when the air is damp or humid, like in the tropics, at 80% rH. Then when the water forms as sweat on the body, it is more difficult to evaporate or there is both evaporation (body loses heat) and condensation on skin (body gains heat) with a net heat exchange which is far less than when in a dry condition.

Thus, the feeling is that your body feels so much hotter as the sweat does not seem to evaporate or that the water is always there on your body - thus leaving the person feeling so much worse than at the same temperatures but much dryer.

The body does not lose as much heat and hence it feels much hotter than during dry conditions.

This can be seen at the marathons as there are NO timings which are world class times, even though the same world class runners come here to run at the same marathon distances and have just clocked far better times in the temperate countries.

 Temperature Vapor pressure Heat of vaporization,    ∆Hvap

   [°C]             [kPa[100*bar] [J/mol][kJ/kg] [Wh/kg]

0.01          0.61165 45054 2500.9 694.69 1075.2

2          0.70599 44970 2496.2 693.39 1073.2

4          0.81355 44883 2491.4 692.06 1071.1

10           1.2282 44627 2477.2 688.11 1065.0

14           1.5990 44456 2467.7 685.47 1060.9

18           2.0647 44287 2458.3 682.86 1056.9

20           2.3393 44200 2453.5 681.53 1054.8

25           3.1699 43988 2441.7 678.25 1049.7

30           4.2470 43774 2429.8 674.94 1044.6

34           5.3251 43602 2420.3 672.31 1040.5

40           7.3849 43345 2406.0 668.33 1034.4

44           9.1124 43172 2396.4 665.67 1030.3

50           12.352 42911 2381.9 661.64 1024.0

54           15.022 42738 2372.3 658.97 1019.9

60           19.946 42475 2357.7 654.92 1013.6

70           31.201 42030 2333.0 648.06 1003.0

80           47.414 41579 2308.0 641.11 992.26

90           70.182 41120 2282.5 634.03 981.30

96           87.771 40839 2266.9 629.69 974.59

100           101.42 40650 2256.4 626.78 970.08

110           143.38 40167 2229.6 619.33 958.56

120           198.67 39671 2202.1 611.69 946.73

140           361.54 38630 2144.3 595.64 921.88

160           618.23 37508 2082.0 578.33 895.10

180           1002.8 36286 2014.2 559.50 865.95

200           1554.9 34944 1939.7 538.81 833.92

220           2319.6 33462 1857.4 515.94 798.54

240           3346.9 31804 1765.4 490.39 758.99

260           4692.3 29934 1661.6 461.56 714.36

280           6416.6 27798 1543.0 428.61 663.37

300           8587.9 25304 1404.6 390.17 603.87

320            11284 22310 1238.4 344.00 532.42

340            14601 18507 1027.3 285.36 441.66

360            18666 12967 719.8 199.9 309.5

373.946            22064 0 0.0 0.0 0.0

 

a 5K Run in the Blistering Morning Vesak Day

 

The Frumpy Old Geezer Look 

I'm writing this in the comfort of my attic, after having completed a decent 5K run in the blistering hot morning over here in S'pore. While the weather at 9.20 am (yes I am a late riser), was already in the low 30s, I was determined to return to my old running schedule one way or the other.

You see, 2 weeks ago, I went and had an X-ray done at the S'pore General Hospital on both knees and while the assessment was mild OA onset, I am clearly mindful I can count the number of runs left me - maybe I have a decent 9 years before I have to accept the end of my running days.

Today's 5 K run (12.5 rounds of 400 m) was done and dusted at 39 minutes flat or on average a 7 minutes 46 seconds. Not fast times like last time but "Hey" who is counting the time ?? 

The orthopaedic doctors there thought I was a 'tough guy' to be able to consider running in my (very early) 60s but I am DETERMINED to succeed. My goal is to finish (maximum)  5 more marathons - hopefully all overseas and I will  finally call it a day.

No knee surgery, no wheelchair for this old fart, for the forseeable future, I am hoping.

  

I wish to grow old gracefully - if given the chance.

If there is one big wish I have, as I approach old age (to me that would be 80 years old).is that I would like to have for as long as possible, and in the due process, I wish that I can have the following 'abilities' which we take for granted when we are young (say from early childhood till 60).  

a) mobility, balance and endurance

b) have as clear a mind as possible (memory, cognitive function,direction,visual acuity) 

c) have all my hair   (LOL)

d) keep trim.  

e) can go to the toilet unaided

f) have a good night's sleep.

g) have a good appetite.

I see many people every day in the HDB estate nearby my office. Many are on mobile wheelchairs, some are bent and cannot stand straight and may be with or without their helpers or maids. The sight is getting very common in practically every Government and private housing estate.

We are a rapidly aging society. That is a fact. 

Singapore has one of the lowest total fertility rate or reproducing rate in the world, for every couple, our reproducing rate is 1.05 per every woman adult. Men cannot reproduce, hence only the women matter (of course I am joking !). 

While all the above 7 are deemed as normal processes of a working body, with each passing year, these 7 seem to be harder and harder to attain and maintain.

I pray that the longer I remain on this Earth, the wiser I get and the more patient I am of other people and less demanding on myself.

Price Elasticity and Inelasticity - what it all means.

 

The picture says it all. The total revenue for a product for example, is directly dependent on 2 factors.

a) Price per unit

b) Quantity Sold.

The sweet spot normally is where the Demand Curve (sloping downwards from Left to Right) and the Supply Curve (sloping Upwards from Left to Right) meets, and taking the 'Y' axis on the vertical would be the right Price and taking the 'X' axis on the horizontal would be the number of units sold AT THAT PRICE.

So, when would a product be deemed to be Price Elastic or Price Sensitive ?

PRICE ELASTICITY

It would be so, when for example, the item, lets call it a Kueh Lapis (multicolored desert) is first priced at $2.50 or at the top end of the green box. When the Kueh Lapis is sold at $2.50 and the demand is 35, then the total revenue would be as stated in the green zone or 35 x $2.5 equals to $87.5.

When the seller at the end of the day cant sell the remaining Kueh Lapis, and he reduces it to $2.0, there is a surge in orders or 55. Hence his revenue will then be $2.0 x 5.5 or $110.

The downside would be that he would need to make and sell more (55) for lower margin but the total revenue would be MORE than if he made less and sold them at a higher price.

Price Elasticity occurs when there are many other substitutes (many other snacks vying for my stomach when I need a pick me up, savory, sweet or just a bun), hence, people will buy more of this product when they deem it to be 'cheap' or inexpensive and can stretch their dollar to fill their stomachs.

Circumstances when price elasticity occurs :

a) many competitors and substitutes

b) small  price change and people are price sensitive. (daily necessities would be ideal catagories, such as toothpaste, toiletries, soaps, consumables, snacks,soft drinks and running shoes or sneakers are items which come to mind). 

This is PRICE ELASTICITY.

PRICE INELASTICITY

This would be when the product (say for example) petrol is priced first at $2.30 per litre, As there are very few other substitutes to petrol (once can downgrade the quality of his petrol, or else take public transport eschewing totally the need for his own transport but we are discussing the transportation function, say for a Grab Car Driver).

So hypothetically speaking at $2.30 per litre, the guy buys say 30 litres, and the total output he pays would then be $2.3 x 30 or $69.

If the price shoots up to $2.40, the poor guy still needs to fill up his tank, and so he skimps and tries to shorten his commute routes via Google Maps, he would still need close to 30 litres. So he is forced to buy 28 litres.

His overall outlay would then by $2.4 x 28 or $ 67.2

Price Inelasticity would occur when there is an oligopolisitic market (few players dominating the market such as petrol) and the item is deemed as a luxury item (branded handbags, designer shoes, petrol are 3 such products which come to mind). 

So which product technically is 'better' to sell ?  The one sold in price elastic market or the price inelastic one ?  The answer is "It Depends". 

Well, lets look at the cost or making these products.

a) For Kueh Lapis, say the cost of making one Kueh Lapis (time, ingredients, petrol to send to shop, rental, portion of business owner salary etc etc) is $1.00.

Then to sell 55 per day his margin would come to $55 daily. Working 6 days a week, that is 24 days per month, the gross margin from Kueh Lapis would be $1,320.

Of course, the seller would try to make as many different sweet desserts as he can in his stall, so this number above is totally meaningless. Unless  he can estimate the rest of his sweets and desserts he sells per day, can the owner then multiply the different margins he makes from the other desserts / sweets to see if his profit gained every month is worth his time, rent, and all the other fixed and variable expenses spent.

The same goes for the Petrol Station, as these are giant multi layered and multi country business entities which have been operating profitably for decades, making billions each year.

The bottom line is this :  If you want to go into business, choose one which has few competitors, and stick to price inelastic market places where you have a distinct advantage in your value add (whatever it is) and serve that small niche quietly. 

 

2016 Barcelona Visit

 

Plaza de Catalunya Dec 2016

Parc Guell Dec 2016 

La Rambla 

La Pedrera 

Recently as I was scanning through the old photos of our visits to Europe (we have had 5 self made tours in the last 7 years, with exceptions for 2020 and 2021 due to COVID), I chanced some lovely pictures of our visit 5 days 4 nights to Barcelona in South Spain.

The Catalan city is everything  they say it is,good and bad.

1. Antoni Gaudi and Joao Miro and their buildings are very part of the landscape.

2.It is the capital city for pickpockets and petty thievery. I had my new Samsung Note 10 stolen right under my nose.

3.  Football is a religion of sorts, we noticed the fans from Germany (Bayern Munich) were in town for a game at the Nou Camp (Barcelona FC is world class) and the place was half filled with Germans.

4. The Spanish Tapas is second to none. The Catalans (they are very proud of their heritage so they insist on being called Catalans first, Spaniards second) have a 'grazing' - as in cows method of eating their dinner. They will meet group A for Happy Hour at (say) 6pm and have a Campari Soda and tapas at one place perhaps near La Ramblas, then at 8.00 pm adjourn to Born (a small suburb filled with bars and flamenco clubs) for round 2.

5. The Walking Street La Rambla is marked at one end by the statue of Cristoforo Columbus (above) (an Italian explorer not Spanish) who was commissioned by the teenage Queen Isabella to go and conqueor the New Worlds in the mid to late 15 th Century (that is 1480 onwards). He went Westwards and landed  on the islands we now know as the Caribbean islands near Florida. Seeing the dark skinned peoples, he mistakenly thought he had arrived in India !

6. La Pedrera was a house designed by Antoni Gaudi and every angle you look at it, you will find that it is all curved, there are no sharp corners at all. At the top of the house, there are these chimneys which look like something from Star Trek - the last frontier.

7. At the top end of the city of Barcelona, there is the Plaza de Catalunya and Parc Guell (a park which was solely designed by Antoni Gaudi). 

7. My wife and I climbed to the top most of Parc Guell overlooking the entire city and found there was an old American chap playing the best 'Blues' riffs I have ever heard. Standing atop the small mound, looking at the city and the seascape and with the sounds of the Blues playing in the background, the feeling was a mixture of euphoria and grandiosity. In short, it was magical.

The picture taken above at the old tree at the top shows me fully relaxed and feeling reflective, 

 

To Achieve Something I need to Try, Fail, Try Again, Fail, Try 3rd Time, Fail, Try 4th Time then Succeed.

The title of this post sounds more like a joke than what I have just experienced today.Recently I bought a beautiful painting from local artist Mr. Ong Hong Seng who had an exhibition through the walkway of the NUSS guild house Kent Ridge premises for the month of March till Mid May (19th to be exact).

I was very pleased with my purchase and decided to hang the artwork titled "Swimming with the Dragons " in my office premises and would take Pride of Place and I am hoping it would be a conversational starter to family, friends and business associates who happen to drop by for a visit or a cup of coffee.

So this morning, I went to the office all charged up with my purchase and bought 2 sets of 3 M super sticker (8 sets which apparently was designed to hold up to 5.4 kg of weight) and I strategically placed them as per the instructions on the sealed package which came with instructions - I am notoriously bad at following written instructions - that is one of my weak points. 

To be 'kiasu', (or afraid to lose), I also popped by opposite hardware shop on my first trip to the office to get the even higher load hanger (5.4 kg), as the painting came equipment with tied in rope which you could hang from a heavy duty hanger.

First Try - Fail 

My first attempt was to unstick the 8 sets of sticky tape behind the painting, it seemed to work - for a good 30 seconds. Then Bam ! the painting fell down to the ground.

Second Try - Fail Again 

I then tried, using the Heavy Duty Hanger. I carefully climbed up the small ladder and ensured that the Heavy Duty Hanger was at the appropriate height - the painting must be high enough to command enough PRESENCE. Again I pasted the Heavy Duty Hanger and put the rope around the Hanger. It did not even last 5 seconds and fell down again. Bam ! for the second time.

Undaunted, I went across the road to the Hardware shop. This dumb un hands-on guy. I went and bought a heavy duty hammer and 2" nails for concrete, thinking that it would do the trick.

Third Try - Fail Yet Again

Upon reaching the office, which was quite the mess now, with wrappings, ladder, sticker peels and other display items all strewn all over the place, I proceeded again to gingerly climb up the ladder and stretch myself to try to knock the 2" concrete nail (I brought 2 with me) into the touch concrete wall. The first nail, went flying after a few blows.

I still persisted, and tried the second nail. I proceeded banging or trying to hammer in the second 2" nail into the concrete. I realised soon enough that the 2" nail was 1" too long.  I would end up hammering into the evening (I started at 11.20 am today) if I pursued with my useless endeavor.

Fourth Try - Hallelujah ! 

So, down I went and I made another trip to the next hardware shop. I was embarrased enough NOT to return to the first hardware shop. I went to the corner shop and bought this time 1" nails. Not too long and not too thick -like my head.

After about 10 hard hammers Voila ! The nail stuck in the concrete !

I gingerly placed the picture and arranged it so that it wouldn't be 'sang nek' or slant to one side.

The Picture finally was UP ! and it gave my office a classy look and feel.

My satisfaction was really deep and my joy was immeasurable.

Life is like that. Business is like that.

You try, you fail. Pick yourself up, accept the brickbats, the criticisms and try again with tweaks in your approach and experience the bitter fall downs.

When it is finally there, like my picture - SAVOUR the feeling.

Is it worth the sweat, effort, risk and money ?  YES.

 

May 13th Sweltering Heat Wave has been hitting Singapore

Today we are experiencing a heatwave. The weather this past week has been hovering in the mid to high 30s C and every kind of exercise will require double the effort and lots of rehydration. I decided not to go cycling at 10 am - which is something of a routine for the past 3 months or so, and decided to go home early and do some household chores.

Late in the afternoon, when it was slightly cooler, I did some light exercises and some gardening. At the 3rd age, I must be mindful of the vagaries of my age and take appropriate measures that I do not overstrain my body.

The heatwave is a consequence of the world's global warming which I am fearful has reached the 1.5 C tipping point of no return and like what the climate experts have said all along. Countries which always have had relatively mild weather, will have to brace themselves for weather shocks and the ones who are not prepared, the citizens will be worse for it.

A recent run at night at West Coast Park