THANKS FOR THE CHRISTMAS PRESENTS

Dear Best Friends,

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Christmas in this year is quite different from the ordinary one. That is---- I was very busy with my examinations,, and with my work in the whole December, I did not go to celebrate for christmas holidays, but I got lots of christmas gifts and SMS from my best friends.

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.(今年花都有???)

.(CROSS筆我最鐘意)
Thanks very much for your presents. I like them very much.
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Best regards
Ken Ngan

Conferment of the title "President Emeritus" to the retiring President

Dear all, - A mail I received from the University Council, this mail reported that the university council of PolyU HK has decided to confer the title of "President Emeritus" on Mr. Poon Chung-Kwong (President Professor)upon his retirement on 1 January 2009. The title of "President Emeritus" is a tribute to Mr. Poon's 18 years of dedicated and outstanding service to the Polytechnic University since January in 1991. . Mr. Poon who has made towards the overall development of PolyU, particularly his achievements in leading the institution's development from a polytechnic to a university, in elevating the University;s staffing and research quality, and in soliciting support from donors and acquiring lands from the Government which provided much needed resources and facilities for the various strategic initiatives of the University. . By copy of this mail, I wish to make best wishes to his long and rewarding retirement. Ken Ngan 07536141G MSC

My Favourite Movie of 2008 (Wushu's Movie- Ip Man)

Dear friends, - What's my favorite movie of 2008? It definitely is the movie "Ip Man".This movie adapted from the life story of Ip Man- the grand master of the Wing Chun Style of Kung Fu and sifu of legendary kung fu superstar Bruce Lee. The movie "Ip Man", I think, that will be the first important record of Ip Man's life. Honestly, I didn't know who is Ip Man before this movie, Donnie Yen who is a good actor, he played well the role of Ip Man in this movie and expressed Ip's persistent devoton to Wing Chun, Wing Chun is a classic example of the love and respect, this movie is a concept, a spirit, a way of thinking- and it exemplifies a new peak in Hong Kong's wushu movies. - Donnie Yen - In the movie, Master Liu who said: I wanna fight against Three (3) persons, IP Man also spoke to the Japanese: I want Ten (10), and in the real life, I will say "I want to fight with 13, to fight with 13 pillows, not persons" Just a joke. Ken Ngan

Show & Tell

1. Introduction
This was an individual report requested by Professor. Shi, the instructor of the Subject: CORROSION CONTROL ME571. This report deals with several real life examples of corrosion / oxidation and will explain why and how the corrosion of metals happened or worked. The main aim of the report is to catch the cause-and-effect relationship of the corrosion and to recommend ways of preventing and controlling corrosion.
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2. Show & Tell of Atmospheric Corrosion
Atmospheric corrosion is surely the most visible of all corrosion processes, e.g. rusty bridges, flag poles, buildings and outdoor monuments. It has been reported to account for more failures in terms of cost and tonnage than any other type of material degradation processes. While atmospheres can be classified into four basic types, (1) Industrial, (2) Marine (3) Rural and (4) Indoor Atmospheric Corrosion.

The following findings can be found everywhere in real life, some or all of them are likely to live with our living areas.

3. Findings:
-Real Life Example: (Description of the atmospheric corrosion of sewage pipes)

Location: Kai Tak Nullah
Figure 1: Location of the affected sewage pipes in Kai Tak Nullah

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The pictures below (see Picture 2 and Picture 3) show the allegro wastewater was continuously splashing on the pipe surfaces, particular underneath the pipelines, such environment typically have high percent relative humidity (% ＲＨ) and will provide an aggressive electrolyte for the promotion of corrosion.

In fact, these pipelines in Kai Tak Nullah almost have 40 to 50 year history, they are in summer time exposed to a high-temperature atmosphere and their bottom sides are all the time contacting with the sewage. It can be referred-to in note 5 of this taught subject, a fundamental requirement for atmospheric corrosion processes is the presence of a film electrolyte that can form on metallic surfaces when exposed to a critical level of humidity (see picture 3 above), especially under conditions of alternate wetting and drying.
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In addition, unexpected rapid corrosion can be seen as well from the following picture, two different levels of corrosion on pipeline surfaces are viewed, the pipelines at column 2 and 3 their surfaces absorbed moisture (the pipe surfaces appeared saturated condition compared to that at column 1), and grew a thick layer of corrosive product on their surfaces.

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• 4. Factors affecting atmospheric corrosion
  Temperature
  Temperature plays an important role in atmospheric corrosion in two ways. First, there is the normal increase in corrosion activity which can theoretically double for each ten degree increase in temperature. Secondary, a little-recognized effect is the temperature lag of metallic objects, due to their heat capacity, behind changes in the ambient temperature. As the ambient temperature drops during the evening, metallic surfaces tend to remain warmer than the humid air surrounding them and do not begin to collect condensation until some time after the dew point has been reached. As the temperature begins to rise in the surrounding air, the lagging temperature of the metal structures will tend to make them act as condensers, maintaining a film of moisture on their surfaces.
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  Relative Humidity (RH)
  RH is defined as the ratio of the quantity of water vapor present in the atmosphere to the saturation quantity at a given temperature, and it is expressed as %. The critical humidity level is a variable that depends on the nature of the corroding material, the tendency of corrosion products and surface deposits to absorb moisture, and the presence of atmospheric pollutants. It has been shown in the above example 1, the critical humidity level is predicted to be 85 to 90% because the bottom surface and the surface around the whole pipe are quite near the splash zone. In the presence of electrolytes, atmospheric corrosion proceeds by balanced anodic and cathodic reactions. The anodic oxidation reaction involves the corrosion attack of the pipe surface, while the cathodic reaction is naturally the oxygen reduction reaction.
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  Wetness in A Long Period
  A resident (say me) has been living in Wong Tai Sin and living with Kai Tak Nullah for over 30 years, the mentioned pipelines installed in the said location should at least be 40 years long.
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  Moisture and Pollutants
  Dew and condensation are undesirable from a corrosion standpoint if not accomplished by frequent rain washing which dilutes or eliminates contamination. A film of dew, saturated with acid sulfates, and acid, chlorides of an industrial atmosphere provides an aggressive electrolyte for the promotion. Also, the stagnant moisture film either becomes alkaline from reaction with metal surfaces, or picks up carbon dioxide and becomes aggressive as a dilute acid.
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  5. Prevention of sewage pipe corrosion is suggested in several ways:
  Organic Adsorption Inhibitors, organics that coat metal with an oily surface layer will protect it. Inhibitors are commonly used in acids, although a few function in neutral or alkaline solutions. In adsorbing on the pipe surface, they replace adsorbed sewage or wetness and their hydrophobic action prevents water from solvating metal ions or prevent H+ ions from adsorbing at cathode sites where reduction to H2(g) could occur.
  
  Plastic cover plate to be added underneath of each sewage pipe, the function of this can isolate the contact point between the splash level and the bottom of pipe
  
  Always keeping the vertical distance between the bottom of pipe (or the bottom of the proposed plastic cover plate) and the waterline as long as possible so as to minimize the splashing effect.
  
  Periodically check and examination of the pipeline systems are should be carried out at least 3 months in order to control and monitor easily the corrosion products.
  
  
  6. Reference:
  Course Notes (ME571 CORROSION CONTROL)
  CORROSION CONTROL Second Edition, Bradford Samuel A.
  http://www.corrosion-doctors.org/Corrosion-Forms/area-effects.htm

Best Regards

Ken Ngan

Help

Dear all

Being a student is not easy these days. All of us have to bury our nose in the notes and reference books day in and day out in order to maintain our grades or stay ahead.

People living in the world have to help mutally, classmate in the same subject must do likewise. He helps you, you help him, people help people!
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Ken Ngan

We all were Tai Fu Bond

Dear friends . Last Monday, it was a banal day until I got a call at office hours and heard a familiar voice. The call from Edwin Chan, who was my formerly classmate in the secondary school date, we were educated in Bethel High School together in 1981-1985. Truly, his call actually brought me back to the school date because at that moment we were happy very much. For about fifteen years ago, the school was relocated to Yuen Long district, its original area is now a divinity school in Kowloon Tong. I remember the school date in Bethel High School we all were naughty students and we founded a naughty student group "Tai Fu Bond 大褲幫", we were several members at the beginning but were 20 more in the end. Each of Tai Fu Bond members had to wear a pantalettes 多摺蘿蔔長褲and must a pair of cuspidal shoes 尖頭鞋, such dressing was viewed as the "IN-THINGS" at that moment. . Personally, I don't think such dreassing as School Uniform and joining in Tai Fu Bond at that age were all that bad, even at this age, as long as we can handle it and separate it. Teachers in the school saying that the principle of "play while playing and work while working" must work very well as long as we can use it. Having naughty act in the school date is actually quite normal but having without it the date to each secondary school student will be a mundane world. As a naughty age and a call, Edwin's call brought back many pleasant memories. . Edwin Chow currently is working at a financial planning company as a planning consultant, who had a nickname in the secondary school as "Little Hippo 河馬仔" but in my mind, he is still a little hippo,. is a little hippo in Tai Fu Bond. He is,.....he definitely is. . (In a summer time in 1984, this picture shows the first left is "Four-Eyes Fat四眼肥", after the first is "Pui Pui佩佩", and then is "Little Hippo河馬仔" and the last is me). At that time, we all were teenagers and had the time to be spent, and had happy with days. Acutally I really had a wonderful time in Bethel High School. . By this blog, I wish little hippo could find remarkable success in his work. Best Regards

My assignment with "GOOD" comment

Basic Function of the gas-fired cooker The following figure is a view of a conventional gas-fired cooker (or it is said to be “Portable domestic gas-fired cooker”). As illustrated, the gas fired cooker comprises (1) a case for gas canister, (2) Gas Burner, (3) Ignition and Heat Control Knob, (4) Gas cartridge Locking Lever, (5) Pan Support, (6) Spill Pan Protection, (7) Brand Name (Ken Ngan, name of the Designer) and (8) Model Number of the gas fired cooker (07536141G). The main function of “Ken Ngan” portable cooker is mainly used to produce heating, it is ideal for camping & outdoor cooking preparation. The model “07536141G” provides controllable heat from 2Kw flash-fry temperatures down to a steady simmer for fondue or sauce and an automatic Piezo electric ignition. . Other features and specifications of the gas-fired cooker are listed below: Max heat output: 2Kw Weight: 2Kg Uses a 220g gas canister Lightweight design for easy transportation Aluminum burner head (see legend 2) Spill pan protection (see legend 6) Pressure sensitive safety device Adjustable heat control (see legend 3) . Choice of Gaseous Fuel & Port Loading required by the burner To design a portable gas burner which has a number of circular ports arranged in a circle. The circle diameter in this design is constrained to be 160mm (6.3 in.). The burner must deliver 2KW at full load and operate with 40% primary aeration. To streamline the design process, some constraints I have to make before starting my design steps. . For stable operation, the loading of an individual port should not exceed 10W/mm2 of port area (this is the 1st constraint). Also, the full load flame height should not exceed 20mm (this is the 2nd constraint). . As for choosing a suitable gaseous fuel for this portable gas burner, the heating value performance and the cost are obviously important. According to the referential information indicated in item 2.2.2 (Heating Value, at page 6 of chapter 2), heating values of different gaseous fuels can be found as per the following tables. By burning the same volume of gaseous fuels, butane gas (C4H10) provides the highest heating value whereas that of producer gas is the lowest. When the weight of fuel is a major consideration, hydrogen has the highest heating value per unit mass which is almost 3 folds of that of butane gas. Producer gas also has the lowest heating value in MJ/Kg. Considering the heat value, producer gas is the poorest gaseous fuel and it will not be chose. . As it can bee seen from the above tables, hydrogen has the highest heating value per unit mass and butane gas has the highest heating value by comparing the same volume with other gaseous fuels. Hydrogen gas is very rare in the local market and it is not safe to be cooking fuel, however, other gaseous fuels such as Propane, Butane, Methane and Natural gas are commonly used in general commercial or domestic areas. The first table shows the Butane gas (C4H10) having the highest heating value in 119.7 MJ/m3, but the heating value of Butane in MJ/Kg (it is 49) is slightly lower than that of Methane (54.9), and even that of natural gas (53.6) and propane (49.8). . Basically, low cost and availability in local market are the main factor in my design assignment; Butane’s price is not expensive compared to the above competitors’ prices. For some reasons, the fuel gas I chose for this portable gas-fired cooker is Butane Gas. . Calculation for the number and the diameter of the ports: Having a design that meets the preset constraints (e.g. circle diameter of the gas burner: 160mm; burner consumption: 2KW; 40% primary aeration; flame height not exceed 20mm; and loading of each port not exceed 10W per mm2), the following calculations can help to check that the overall design makes physical sense. Step 1: Apply port loading constraint. The total port area is Atot = (πND2)/4 And the constraint is (ṁFΔhc) / Atot = 2000W / Atot mm2 = 10W/mm2 Thus, ND2 = 4 (2000) / 10π= 254.6mm2 If ND2 = 254.6mm2 Choosing a value for N (or D) and calculate D (or N) as a first trial for the design. In this design, I chose N to be 36 yields, therefore D, diameter of each port will be 2.66mm. Step 2: Determine flow rate Ǭ= 2000W = ṁFΔhc ṁF= 2000W / 45,742,000J/Kg (this value as per the fuel properties, Butane LHV) ṁF= 4.37 x 10-5kg/s The primary aeration determines the flowrate of air premixed with the Butane fuel C4H10: C4H10 + a(O2+3.76N2)à Products a = 4+2.5=6.5 C4H10 + 6.5(O2+3.76 N2)à Products C4H10 + 6.5O2+24.4 N2à Products C4H10= (12 x 4 + 1 x 10) =58Kg 6.5O2+24.4 N2 = (6.5x16x2 + 24.4 x 14 x 2) = 208 + 683.2 à 891.2Kg Air/fuel ratio (stoic) = 891.2Kg / 58Kg Air/fuel ratio (stoic) = 15.37 . ṁA, pri= 0.4 (A/F) stoic ṁF = 0.4 (15.37)4.37 x 10-5kg/s = 2.69 x 10-4kg/s . A/F = ṁA, pri / ṁF A/F = 6.156 Equivalent Ratio Φ=A/F stoic / A/F = 15.37 / 6.156 Φ= 2.497 Φ> 1, it implies fuel rich mixture. . The total volumetric flowrate is Qtot = (ṁA, pri + ṁF )/ƥ . To determine ƥ, the ideal gas law will be applied where the mean molecular weight is calculated from the composition of the air-fuel mixture: X A, pri= NA/ (NA+NF) = Z/ (Z+1) Where Z is the primary molar air-fuel ratio = (x+y/4)4.76(% aeration/100) Z= (4+2.5) x 4.76 x (40/100) Z= 12.376 . X A, pri= Z/ (Z+1) = 0.9252, X F, pri= 1- X A = 0.07476 MWmix = 0.9252 (28.85) + 0.07476 (58) = 31.03, ƥ = P/ (Ru/MWmix)T = 101325/ (8315/31.03)300 ƥ = 1.260kg/m3 and Qtot = (2.69 x 10-4 + 4.37 x 10-5)/ 1.26 Qtot = 2.48 x 10-4 m3/s . Step 3: Check the flowrate per port is QPort =Qtot / N = 2.48 x 10-4 m3/s/ 36 = 6.89 x 10-6 m3/s Step 4: Check practicability of design. If 36 ports equally spaced on a 160mm diameter circle are to be arranged, the spacing between ports is L = rθ= (160mm/2) x (2π(rad) /36) L= 14mm This spacing seems reasonable, although it is not clear whether or not the flames will form independently or merge. Since all of the constraints are satisfied with the 36 port design, iteration is not required. . Adopting Flame Type for gas-fired cooker In real life, a flame produced from the burner is impinged upon a surface to transfer heat obtained from the combustion via convention, radiation and thermo-chemical heat release. Heat will be transferred to the other side of the surface by conduction with a small amount of heat loss to the surroundings. The flame characteristics of this portable gas-fired cooker are required to have low emissions of air pollutants, rapid ignition and combustion, stable and safe over the entire range of operation. . Considering the emission problems of the cooker In the domestic gas-fired combustion systems or portable gas-fired cookers, emissions of particular matter, carbon monoxide, sulfur dioxide and hydrocarbons are rather low because of the use of very fine and clean fuels, the gaseous fuels. This is even obvious when a better gaseous fuel, such as natural gas, is used. . As for butane gas which is sold bottled as a fuel for cooking and camping. When blended with propane and other hydrocarbons, it is referred to commercially as LPG. Butane is also used as a petrol component, as a feedback for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters. Butane gas belong to the alkanes family CnH2n+2, using these gaseous fuel as the gas for portable cooker will be most likely to decrease the emission problems because butane contain negligible sulfur and organic nitrogen, but carbon dioxide and nitrogen are sometimes present. In addition, non-combustible substances are very low. Best regards Ken Ngan (Nov)

Gold Fish Market

Dear Friends;

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If you are a fish lover, then Gold Fish Market on Tung Choi Street in the heart of the Mong Kok District is where you want to be. Dozens of shops, one after another, are dedicated to the creatures from under the sea. Whether its a new fish you fancy, are just looking to spruce up your aquarium, or are in some need of some good luck.

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Tung Choi Street (Gold Fish Market)
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Many Chinese people believe that a gold fish properly postioned in the home can bring them good luck. Some said: 6 numbers of Black fishes, or 2 or more than 2 numbers of Dragon Fishes will bring in some good luck or fungshui.

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Tung Choi Street can provide you with all three of those things. A great street that is just mind blowing when you see how many fishes are hanging in little plastic bags on both sides of the road. A must see while in Hong Kong!

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Address: Sung Choi Street, Kowloon
Directions: By MTR : Take the Tsuen Wan Line to Prince Edward. Head towards Exit B2 on Sai Yeung Choi ST. South. Take a right down Sai Yeung Choi, then a immediate left down Nullan Road. Nullah road takes you right to Sung Choi

Best Regards

My friend's wedding + Mid-Autumn Festival + Avenue of Stars

Dear friends

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Mid-Autumn Festival

Today is Mid-Autumn Festival, it is also known as "Moon Festival" and is a very popular East-Asian tradition of Chinese origin, dating back over 3,000 years to moon worship in China's Shang Dynasty that spread to neighbouring cultures like Japan, Taiwan, and Singapore. The Mid-Autumn Festival falls on the 15th day of the 8th lunar month of the Chinese calender, this year on today is 14 September 2008 in Gregorian calendar.

Wishing you and your family a happy moon cake festival!

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Yim's Wedding at Mid-Autumn Festival

In this year of Mid-Autumn Festival, it is very important and is a memorable day to one of my best friends, he chose his wedding on 14 September 2008 because he and his wife wanted having a memorable day and celebrating their wedding anniversary together with next Mid-Autumn Festival. His wife said Mid-Autumn Festival will be a reminder to her husband,....so therefore, he should know what shall he do next year.

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Avenue of Stars
After his wedding, we took a ramble at Avenue of Stars because this famous avenue is building at the nearby TST cultural center. The Avenue of Stars which is located at the Tsim Sha Tsui Promenade was given a glittering official opening on 27 April 2004. This avenue was opened to the public and visitors from all over the world from 28 April 2005 onwards. I took some pictures from there and now wanna share them with you, see the below pictures:

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Best Regards