Monday, March 23, 2015

Mr Lee Kuan Yew passing on 23rd March 2015

Today marks the whole of Singapore mourning to the man who build a third world country into a first world country. Mr Lee Kuan Yew. 
 Lived to an age of 91 whose wife left him 5 years ago at 89. 

Extract from Channelnewsasia 

SINGAPORE: Mr Lee Kuan Yew, who was Singapore’s first Prime Minister when the country gained Independence in 1965, has died on Monday (Mar 23) at the age of 91.
"The Prime Minister is deeply grieved to announce the passing of Mr Lee Kuan Yew, the founding Prime Minister of Singapore. Mr Lee passed away peacefully at the Singapore General Hospital today at 3.18am. He was 91," said the PMO.
Arrangements for the public to pay respects and for the funeral proceedings will be announced later, it added.
Mr Lee, who was born in 1923, formed the People’s Action Party in 1954, then became Prime Minister in 1959. He led the nation through a merger with the Federation of Malaysia in 1963, as well as into Independence in 1965.
He leaves behind two sons – Lee Hsien Loong and Lee Hsien Yang – and a daughter, Lee Wei Ling.
From early in his life, Mr Lee Kuan Yew had braced himself to face history’s tumultuous tides head-on.
His efforts to build a nation were shaped by his early life experiences.
For the young Lee Kuan Yew, the Japanese Occupation was the single most important event that shaped his political ideology. The depravation, cruelty and humiliation that the war wreaked on people made it clear to Mr Lee that, to control one’s destiny, one had to first gain power.
Born to English-educated parents Lee Chin Koon and Chua Jim Neo, Mr Lee was named “Kuan Yew” which means “light and brightness”, but also “bringing great glory to one’s ancestors”. He was given the English moniker “Harry” by his paternal grandfather.
He continued the family tradition of being educated in English, and read law at Cambridge University after excelling as a student at Raffles College. His experience of being as a colonial subject when he was in England in the late 1940s fuelled his interest in politics, while also sharpening his anti-colonial sentiments.
He said later: “I saw the British people as they were. They treated you as colonials and I resented that. I saw no reason why they should be governing me – they’re not superior. I decided, when I got back, I was going to put an end to this.”
Mr Lee’s political life began right after he returned to Singapore in 1950, when he began acting as a legal adviser and negotiator representing postal workers who were fighting for better pay and working conditions.
He was soon appointed by many more trade unions, including some which were controlled by pro-communists.
In a marriage of convenience to overthrow the British, Mr Lee formed the People’s Action Party in 1954 with these pro-communists and other anti-colonialists.
A key part of winning power at the time was securing the support of the masses, and this meant reaching out to the Chinese-educated, which made up the majority of the population in Singapore. He had taken eight months of Mandarin classes in 1950, and he renewed his Mandarin education five years later, at the age of 32. And within a short time, he had mastered the language sufficiently to address public audiences.
In the mid-1950s, riots broke out that fuelled tensions between the local Government and the communist sympathisers in the Chinese community. A few pro-communist members of the PAP were arrested.
Leading the PAP, Mr Lee fought for their release and ran a campaign against corruption in the 1959 elections for a Legislative Assembly. The PAP won by a landslide, and Mr Lee achieved what he had set out to do – Singapore was self-governing, and he was Prime Minister.
But there were others who would contest the power he acquired, and they had different political agendas. It became apparent that leading Singapore meant having to break ranks with some of his anti-colonial allies – the pro-communists.
Mr Lee said of the pro-communists: “They were not crooks or opportunists but formidable opponents, men of great resolve, prepared to pay the price for the communist cause.”
Mr Lee and his team were well aware of the hard fight they faced against the pro-communists, having seen up close how they could mobilise the masses through riots and strikes to paralyse a Government. And success in this fight depended a lot on Mr Lee’s leadership.
The battle-lines were drawn sharply over the proposal for merger with Malaysia – the non-communists were for it, and the pro-communists were against it.
There were compelling economic reasons for merger, but Mr Lee was also clear about its political necessity. To him, merger was absolutely necessary to prevent Singapore and Malaya being “slowly engulfed and eroded away by the communists”.
He believed that building a common identity between individuals on either side of the Causeway would propel them across racial and religious divides towards a common land. Part of this was making sure that people felt that they are wanted, and not “step-children or step-brothers, but one in the family and a very important member of the family”.
He campaigned relentlessly and tirelessly for merger, speaking over the radio, and in nearly every corner of Singapore. After an intense public contest that pitted him against his political opponents, Mr Lee won and most Singaporeans voted in favour of the union with Malaysia.
On Sep 16, 1963, which coincided with his 40th birthday, Mr Lee declared Singapore’s entry into the Federation of Malaysia.
But this did not mean an easy working relationship between the two sides, and serious differences emerged. Mr Lee wanted a “Malaysian Malaysia”, where Malays and non-Malays were equal, and he would not condone a policy that supported Malay supremacy.
Differences between the two sides grew – from conflicts between personalities and disagreements about a common market, to the PAP’s participation in Malaysia’s general election. Malaysian politicians considered it a breach of understanding for the PAP to take part in mainland politics.
Things came to a head over constitutional rights. Mr Lee addressed the Malaysian Parliament in May 1965, in both English and Malay, laying out his case against communal politics.
But a year after racial riots were sparked off by what Mr Lee called Malay “ultras”, creating a deep divide, Singapore separated from Malaysia on Aug 9, 1965. It was a time of great disappointment for Mr Lee, a moment which he said was one of “anguish” for him.
And so it was that Singapore became an independent state that day in 1965, but not by choice. The island’s 2 million people faced an uncertain future, and that uncertainty weighed heavily on the man who was leading it.
Left with no hinterland and hardly any domestic market to speak of, Singapore’s only option was for its leaders to fight hard for its survival.
And despite the daunting task that loomed ahead, Mr Lee chose to set his sights on building a country of the future, and he never veered from that vision. In his own words in September 1965: “Here we make the model multiracial society. This is not a country that belongs to any single community -  it belongs to all of us. This was a mudflat, a swamp. Today, it is a modern city. And 10 years from now, it will be a metropolis – never fear!”
But this difficult task was soon made more challenging by another crisis. In 1968, Britain unexpectedly announced its intention to withdraw its troops from Singapore. Mr Lee and his team now had to confront the prospect of a country without its own security forces. Worse, thousands of workers retrenched from the British bases joined the already large numbers of unemployed in the country.
Mr Lee’s good ties with British leaders led them to extend the departure of their forces to the end of 1971. These military bases contributed 20 per cent to the economy and provided jobs for 70,000 people, and the extension of the pull-out date softened the blow to Singapore’s economy.
In the face of these looming challenges, Mr Lee and his team soldiered on to hold the fledgling country together, and to make it work. The vacated British naval bases were used to boost the economy, and efforts were made to attract investors to set up industries on the former British army land.
To survive what was then a hostile neighbourhood, Mr Lee adopted a two-pronged approach to grow the economy.
First, to leapfrog the region and link up with the developed world, for both capital and market initiatives; and second, to transform Singapore into a “first world oasis in a third world region”. With first-world standards of service and infrastructure, Mr Lee saw the potential for Singapore to become the hub for businesses seeking a foothold in the region.
Mr Lee most likely saw the possibilities for Singapore, including eventually enjoying the world’s highest per-capita income, and becoming a leading business centre for Asia. He would have attributed such success to the confidence of foreign investors drawn to the nation’s amicable industrial relations.
Former President S R Nathan remembers Mr Lee’s focused approach: “He emphasised that his duty was to find ways and means of getting more jobs for people, and it was also the duty of the labour movement to help their fellow workers find jobs. And so for that, we needed industrial peace and a certain balance, not exploitation.”
The National Trades Union Congress (NTUC) was formed in 1961 when the PAP split. Led by Mr Devan Nair, a founding member of the PAP, the NTUC led Singapore’s labour movement away from militant trade unionism to one marked by cooperation.
This made Singapore the first in the world to have a tripartite arrangement where workers, employers and the Government came together to discuss general wage levels. This cooperation contributed significantly to harmonious labour relations and, ultimately, to Singapore’s rapid development in the 1970s and 1980s.
Mr Lee firmly believed that growth and development of the country was in the best interests of the workers and their unions. Speaking in 2011, he said: “In other words, growth is meaningless unless it is shared by the workers, shared not directly in wage increases, but indirectly in better homes, better schools, better hospitals, better playing fields, a healthier environment for their families, and for their children to grow up.”
Singapore’s metamorphosis from mudflat to metropolis was not just a physical transformation. Equally remarkable was the transformation of the psyche of an entire population. Within the span of a few decades, Singaporeans came to be seen as a people who could get things done.
Mr Lee played a big part in that change. From the start, he set the pace for excellence. He once told senior civil servants: “I want to make sure every button works, and if it doesn’t when I happen to be around, then somebody is going to be in for a rough time, because I do not want sloppiness.”
Sprucing up a young nation however was not so straightforward. Besides the challenge of ensuring sufficient security for the country’s borders, Mr Lee and his team had a more fundamental problem to tackle – that of a housing crisis.
Today, the 50-storey Pinnacle on Cantonment Road stands as an icon in Singapore’s 50-year-old public housing landscape. It is built on the site of one of the earliest public housing projects in the country. But housing in the 1950s was a far cry from what it is today. Slums were common when Singapore achieved self-government in 1959, and there was a full-blown housing crisis.
To meet the nation’s acute housing shortage, the PAP set up the Housing and Development Board in 1960. The aim set for it was to build 10,000 homes a year.
Its predecessor – the Singapore Improvement Trust (SIT) – was highly sceptical that the new board would meet its ambitious target. The SIT itself had built only 20,000 flats in its entire 30-year history.
The stakes were high and the difficulties daunting. The PAP, which had just come into power, needed to deliver results fast and gain the trust and confidence of Singaporeans.
There was doubt even with the Government of whether the HDB could get the job done, and a committee was set up to find out if the board had the capability and the materials to complete 10,000 houses as planned. When the committee published its report, the HDB had already completed 10,000 units of housing.
The HDB’s performance was crucial to the PAP’s re-election in 1963.
But it was more than a question of providing affordable homes for the people. The social motive to do this was equally compelling, and public housing helped tighten the weave of Singapore’s social fabric.
Mr Lee felt that it was important to have a rooted population. He said in 2010: “If you ask people to defend all the big houses where the bosses live, and they live in harbours, I don’t think that’s tenable. So we decided from the very beginning that everybody must have a home, every family will have something to defend, and that home must be owner-owned, but they have to pay by instalments over 20, 25, even 30 years. And that home we developed over the years into their most valuable asset.”
Today, more than 80 per cent of Singaporeans now live in subsidised public flats that they can call their own.
Singaporeans now had a personal stake in their country that went beyond feelings of patriotism. They had a physical space they could call home, and a vested interest to defend it.
National Service, aimed at defending the country and ensuring its borders were safe from external aggression, took on a different dimension.
After independence, Singapore was left with just two battalions of the Singapore Infantry Regiment. There was an urgent need to build a substantial defence force. And so National Service was introduced in 1967, with universal conscription making it compulsory for every male Singapore citizen to serve in the armed forces for about two years. It also contributed to promoting racial harmony.
In multi-racial Singapore, English is the common language used by all races. Mr Lee saw early on that English would be a unifier that would give Singapore an edge in the international arena.
But he also believed that knowing one’s mother tongue would build a sense of belonging to one’s roots, and increase self-confidence and self-respect. And so he championed bilingualism.
In retrospect, Mr Lee said that bilingualism was his most difficult policy to implement. He later admitted he had been wrong to assume that one could be equally fluent in two languages. He said in 2004: “Had I known all the difficulties of bilingualism in 1965, as I know now today, would I have done differently? Yes, in its implementation, but not in its policy. I don’t regret the stress and heavy burdens I put, because the other way would have been a destruction of the chance of building up some form of culture worth preserving.”
Former senior minister of state Ch’ng Jit Koon lauded Mr Lee’s foresight in creating a bilingual society. “If he did not succeed in bringing through our education system based on bilingual education, we will not have the advantage among other countries to tap on China’s economic trade,” he said in 2008.
Indeed, Mr Lee and his team were very sensitive to issues involving race, knowing how combustible such matters could be. The formative years of the PAP, the battles against communism and extremism and the racial riots he lived through meant that Mr Lee never underestimated the potentially explosive nature of race relations.
When it was time to remove the small, dilapidated mosques built on state land, he did so with caution. His plan was to replace these “suraus” with bigger and better mosques in every housing estate through voluntary contributions from the Malay-Muslim community, creating a sense of ownership and pride.
Mr Lee also took special interest in ensuring that Singapore’s different communities would all have a share in its prosperity. He believed better education was one of the keys to uplifting the Malay community.
Cabinet minister K Shanmugam said it would have been easy for politicians in Singapore to appeal to the sentiments of the majority Chinese community to gain political power. But he felt that part of the success of Singapore is due to leaders like Mr Lee, who shunned racial politics.
In an earlier interview in 2003, Mr Shanmugam said: “I think most sensible people in the Indian community, particularly those who went through the earlier struggles, who are older than me, accepted this - that we have the space and we have far more liberty and opportunity in Singapore than we would have if we were 6 per cent in any other society, including India, where many of the so-called upper caste Indians in Singapore would not have had a chance.”
Mr Lee Hsien Loong said that the elder Mr Lee remembered the situation that had existed in Malaysia before Singapore became an independent state. “After we became independent, a point that he always reiterated was – never do to the minorities in Singapore that which happened to us when we were a minority in Malaysia. Always make sure that the Malays, the Indians have their space, can live their way of life, and have full equal opportunities and are not discriminated against. And at the same time, help them to upgrade, improve, move forward,” he said in 2013.
Singapore is widely known for being a clean city, both in terms of its environment as well as governance. It is the least corrupt country in Asia, and according to the World Bank, it is one of the most preferred places in the world to do business.
But it was not always graft-free. Corruption was widely prevalent when Singapore was still a British colony. In the 1959 election, the PAP, then the opposition, campaigned against the Government’s corrupt practices. Mr Lee said at the time: “I am convinced that we will thrive and flourish, provided there is an honest and effective Government here.”
The PAP’s anti-corruption position resonated well with the voters. When the PAP Government took office, Mr Lee and his team turned up in all-white as a promise to the people that their leaders will not stand for corruption and will be “whiter than white”.
Over the years, the leadership’s zero tolerance for corruption earned Singapore a reputation for having a clean and effective Government. Establishing rule of law, public security and safety were fundamental to the success of the PAP.
Mr Lee applied the effort to stay clean to the island’s physical transformation as well. From the outset, he was adamant that urban development in the country did not proceed haphazardly. He had seen how a lack of planning had marred other cities, and was determined that Singapore did not make the same mistake.
Observers say this focus on paving the foundation for Singapore to have a first world environment while becoming a first world economy led to the good environment actually becoming an economic asset. And some felt that the efforts to green Singapore gave a certain softness and calmness to the country, and was not just an aesthetic benefit but spoke to the soul of Singaporeans.
Mr Lee expressed his passion for greening Singapore in practical ways. He planted a tree every year, a tradition he started in 1963. This kicked off an island-wide tree-planting initiative and launched Tree Planting Day, a national campaign that helped Singapore earn its reputation as a Garden City.
Mr Lee wrote in his memoirs: “After independence, I searched for some dramatic way to distinguish Singapore from other Third World countries and settled for a clean and green Singapore. Greening is the most cost-effective project I have launched.”
Mr Lee’s original vision of a Garden City evolved over the years into the concept of a City in a Garden, with about 2 million trees planted around the island.
In June 2012, this transformation was celebrated with the opening of the Gardens by the Bay.
Prime Minister Lee Hsien Loong said this was just one example of how Singapore’s living environment is being transformed. “It may be a densely populated city, maybe one of the densest in the world, but we are determined that our people should be able to live comfortably, pleasantly, graciously. Not just good homes, efficient public transport or safe streets, but also be in touch with nature, never far from green spaces and blue waters,” he said in 2012.
Mr Lee Kuan Yew was not known to be sentimental about buildings or landmarks, and he was practical yet ambitious about transforming the nation’s landscape, even when it came to defying nature.
And one of his most important initiatives started in 1977, and involved the Singapore River – historically the lifeblood of the economy and the centre of commercial activity.
The river had been the conduit for Singapore’s entrepot trade, allowing for the movement of goods from the port to the city. Over the years, it had degenerated into a filthy, congested, polluted waterway. The industries along its banks had been dumping sewage and garbage into its waters. The water was badly polluted and caused a stench in the area.
Mr Lee’s proposal was perceived as a monumental feat: A clean-up of the entire river.
The rebirth of the Singapore River took 10 years to complete, and today, it is not only glistening again, but its banks are also bustling with trendy restaurants, clubs and offices, and fish have even returned.
The Singapore River, now part of the Marina reservoir, is a constant reminder of the man who defied time and tide. Its transformation mirrors the fascinating evolution of a small backwater into a thriving global metropolis, and its currents echo the ebb and flow of one man’s life as he turned an impossible dream into reality.
In Mr Lee Kuan Yew’s own words: “You begin your journey not knowing where it will take you. You have plans, you have dreams, but every now and again you have to take uncharted roads, face impassable mountains, cross treacherous rivers, be blocked by landslides and earthquakes. That’s the way my life has been.”

Sunday, August 26, 2012

Code for 26th Sept

The code for that is "Justin to Edward: dun strike back 4 months before christmas, the payment has been made The location is Siba 525122380173. Cell permit is at 1936.


Saturday, July 02, 2011

July reminder

This is just a reminder to myself.

After 5 years, the event have been locked.

2nd July 2000 hours.

Location, north.
exact location remains unknown.

It is a Saturday today.


Wednesday, June 15, 2011

Code for my own reference

This information is intended only for those concern.

ETA Code: 110518
Referral: Adeline,


Friday, April 29, 2011

Vibration Isolator, a solution to reduce acoustic vibration

Finally, I solved a mystery that has pounded me for the past 4 years. It is sometime in my head because it exist everywhere but the engineers at the place I work in never give an exact answer. One just shun away from the question while other never think of this question before. I still remember one reply saying, "this is nothing important, dunno why they make this thing, waste of money.""Don't bother about it." But I never stop looking for a solution to it.

Inertia Block, this is one item that is commonly found in the plant room everywhere no matter which industry is involved. In plant room inertia block exist in term of concrete and in an Air Handling Units, it exists in form of steel structure. I have been wondering why don’t people just put the equipment on the vibration isolator instead of putting it on a block of concrete as what everywhere does. It does have hard-standing or perforated standing. The solution is brought by Paul N.Cheremisnoff, D.A. Buies & CH Harman in Industrial Noise Control and Engineering Noise Control respectively. The most common found is steel spring but through the explanation, it explains that other than steel springs, there are two other types of isolators such as cork materials and rubber materials. Of course, as mentioned in the article, if the design is within the fatigue limit, steel isolator can have infinite life span providing there is not destruction on the steel properties itself.
Below is some of the extract of Vibration Isolators

Inertia Block

These are usually made of concrete poured into a structural steel frame with reinforcing bars, brackets for the attachment of vibration isolators and mounting bolts for the equipment. Although they are generally referred to as inertia blocks and are normally installed to reduce the movement of the mounted equipment, in most cases they are used for other reasons.

To increase stability of the system

The concrete inertia block provides mean of widening the support and a more stable geometry.

Lowering the center of gravity or centroid

Mounting equipment on a substantial concrete base has an effect on lowering the centroid of the complete assembly. This adds to the improvement of the stability provided by extending the width of the base, and also has the effect of reducing the likelihood of rocking motion.

To give a more even weight distribution

Equipment items are very much heavier at one end than the other. This means that if they are mounted directly on vibration isolator, very different arrangements are needed at opposite ends of the equipment to cope with the uneven weight distribution. If the equipment is mounted on concrete block, the weight distribution will be more even and, providing the block is heavy enough, it may enable a symmetrical mounting block to be used.

To minimize the effect of external forces

Although the use of an inertia block does not improve then transmissibility for a given static deflection, it does means that very much stiffer isolators can be used for the same static deflection, i.e. if the mass of the equipment is doubled, the stiffness of the isolator necessary to support it is also doubled. This means that the equipment is far less susceptible to the effects of external forces such as fan reaction pressure and transient torques due to changes in speed and load.

To provide or replace rigidity

An inertia base can be used to provide rigidity for the mounted equipment in the same way that a steel base is used.

To reduce problems due to coupled modes

The higher of the two rocking sideways coupled movement for a tall item of equipment may occur at two to three times the frequency of the basic vertical frequency. This can lead to resonance problems. Adding an inertia base has the effect of lowering the rocking natural frequency which helps to avoid the problem.

To minimize the effects of errors in estimated positions in the equipment’s center of gravity

When vibration isolators are being selected, it is necessary to calculate the total load on each isolator so that the appropriate isolator can be chosen. This normally has to be done before the equipment is available and estimated positions of the centers of gravity of each item have to be used. If this information is inaccurate, the estimated loads may be considerably different from te ones which occur in practice. This may lead to vibration isolators being grossly under or overload, or to the equipment sitting at an unacceptable tilt. The latter problem becomes increasingly likely as vibration isolators with high static deflections are used. If a concrete inertia base is used, the center of gravity of this is normally made known accurately and if the mass of the base is comparable with the mass of the rest of the equipment, it means that even if the equipment information is not accurate, the possible inaccuracies in the final estimated center of gravity are small. This reduces the possible errors in isolator loading and reduces the likelihood of a tilted installation. The probability of a tilted installation is also further reduced because of the stiffer springs that will be used to carry the additional weight of the inertia base.

To act as a local acoustical barrier

When very noisy equipment is mounted directly on the floor of an equipment room, the floor directly under the equipment may be subject to very high sound pressure levels in the immediate vicinity of the equipment. This local area where the floor is exposed to these high levels may cause problems of noise transmission into the room below. A concrete inertia base acts as an effective barrier, protecting the vulnerable area of the floor.

It should be noted that reduction of transmissibility is not listed as a reason for installing an inertia block. This is because of the transmissibility determined by the static deflection of the vibration isolators, regardless of the presence or absence of an inertia base. The effect on the vibration process on the inertia block is to reduce amplitude of motion in proportion to the increase in mass, i.e. if the mass of the equipment is doubled by the additional of the block, the movement will be reduced one-half.

Unless special conditions dictate a structural analysis for the concrete inertia block, a general rule of thumb currently applied for block thickness is one-twelfth the longest dimension of the equipment supported, and in no case less than 6 inches thick. Concrete blocks need not be thicker than 12 inches unless specifically recommended.

The floor plan shape of inertia blocks should be configured to suit each piece of equipment mounted on the block. This is particularly true in case of pumps where it is desired to pick up weight of connected piping on the inertia blocks.
Once a piece of vibrating equipment has been properly isolated, care should continue to be exercise to see that utility connections to the equipment does not bridge or bypass the isolation system.

Isolator Types

Isolators can be conveniently be divided into three types

• Cork material
• Rubber material
• Steel springs.

Cork material

Cork has been used in many fields of industry as a vibration isolation material. A popular type of cork is made of pure granule compressed together and baked under pressure to achieve a controlled density. Cork materials are used mainly under concrete foundations. The cork will remain reasonably durable under exposure to acids, oil and temperature between 0 degree Fahrenheit to 200 degree Fahrenheit; however, it will be affected upon contacted with strong alkaline solutions. Cork will rot however, from repeated wettings and dryings. As a vibration isolator, cork is limited to frequencies above 1800 cycles per minutes. Because of a great degree of damping in cork, the natural frequency cannot be obtained from the static deflection. As an alternative, the natural frequency can be obtained through tests by vibrating the cork under various loads to find the resonance frequency.

Rubber materials

Rubber is useful for frequencies above 1200 cycles per minutes. Alkali solutions or acids will not affect rubber, but degradation problems could arise if it is exposed to sunlight. For natural rubber, the temperature range from 50 degree Fahrenheit to 150 degree Fahrenheit; for neoprene from 0 degree Fahrenheit to 200 degree Fahrenheit. As rubber ages, it gradually loses its resiliency. The useful life span of rubber mounts is approximately five years under impact applications and seven years under non-impact applications, although it will retain its sound-insulating properties for longer period. Individual molded rubber mountings are economical only with medium and lightweight machines because heavier capacity mounting approach the cost of more efficient steel spring isolators. Rubber and other isolators provide maximum deflection on the order of 0.25 inch. Some steel spring isolators can even reach deflection of 10 inches.

Steel Spring

The most common form of steel spring is a simple coil spring. Provided that the right combination of coil diameter, spring height and wire diameter is used, the springs are stable. They are capable of providing resonant frequencies down to the order of 2Hz. When a coil spring is designed within the material fatigue limit, spring can have an infinite life. Coil springs are virtually un-dampened and if damping is required, this has to be provided by auxiliary means. Steel springs have the disadvantage that at high frequencies vibration can travel along the wire of the coil, causing transmission to the structure. This is normally overcome by incorporating neoprene pad in the spring assembly so that there is no metal-to-metal contact.

Calculation for selection of Isolator

Step 1: Required Isolator Efficiency

An Isolator efficiency of 80% is usually specified. Unless otherwise stated in the requirement.

Step 2: Transmissibility

Given equation, Isolator efficiency = 100(1 - T)
Thus Transmissibility, T = 1 – (80/100)
= 0.2

The maximum transmissibility, T of the system which requires efficiency of 80% is 0.2

Step 3: Forcing Frequency

To determine the value of the lowest frequency, f (i.e. the frequency of X excitation)

With the rotational speed of the motor as 1450rpm, it has to be divided by 60 seconds to obtain forcing frequency in Hz (cycles per seconds
Forcing Frequency, f= 1450rpm / 60 (seconds per minutes) = 24.2Hz

Step 4: Natural Frequency

To obtain natural frequency fn of the isolated system (i.e. the mass of the equipment supported on isolators) required to provide a transmissibility, T for a forcing frequency, f.

Given equation, T = 1 / [((f/fn)^2) - 1 ]

With transmissibility, T=0.2 (determined in step 2); forcing frequency, f = 24.2 Hz (determined in step 3)

Thus, Natural frequency, fn = 9.9Hz.

Step 5: Static Deflection

To find the static deflection, sigmast required to provide the required natural frequency, fn.

Given equation, fn = 3.13 / (sigmast)^1/2

With natural frequency, fn = 9.9 Hz (determined in step 4)
Thus, Static deflection, sigmast = 0.1 inch (2.54mm)

Step 6: Stiffness of Isolation System

To find the stiffness, k required to provide the required natural frequency, fn.
Given equation, fn = [(k/1000m)^1/2 / 2pi]

With natural frequency, fn = 9.9Hz (determined in step 4)
Thus, Stiffness, k = 383 N/mm(2188lb/in)

Step 7: Stiffness of Individual Isolator

Since there will be one isolator at each corner of the base of the support mass, the isolators are in parallel, with n = 4.

Thus, Stiffness on individual isolator = 383/4
= 96 N/mm (547lb/in)

Step 8: Total Load to be Supported by all Isolators

The total load of the system on the inertia base is 99kg.

Step 9: Load on individual isolator

Load is divided equally among the four identical isolators
Thus, loading on individual isolator = 99/4 = 24.8kg (54.9lb)

Step 10: Isolator Selection

Isolator having a spring constant of 96 N/mm (547lb/in) and the capacity to support a static weight of approximately 24.8kg (54.9lb)


Thursday, April 28, 2011

Birth of Air Conditioner 1925

Shopping centers, office,home and last but not least, cinema. These are some of the places that benefits greatly from air conditioning. So how many people actually think of the the question of how the air conditioning started and who started it.

According to the Discovery Science Channel, the invention of the Air-conditioning is merely a study made by a man called Willis Haviland Carrier (1876 - 1950). He discovered a use of the refrigerant and think of ways to improve it again and again. At that time, it is so secret not many people knows about it. He have it patented and acquired patent U.S.808897 in 1906. He patent it as apparatus for treating air. It is to control humidity and temperature. He presented it to the American Society of Mechanical Engineering in 1910. At that time, Air-conditioning is not popular as it is undergo studies and Willis Carrier is still in studying the psychrometrical cycle of the refrigerant.

It wasn't until 1925, one of the movie industry Paramount faces a difficulty. Summer strike, and sales dropped in every summer period where hot air heats up cinemas with no windows and covered with walls. In 1925, Carrier found the problem and approach Paramount a solution to their problem. He persuaded Paramount Pictures Coporation to part with 65,000 dollars to install a climate control device. Paramount at that time is constructing the Rivoli Theatre, a flagship movie house in Times Square in New York City. He installed the machine in the movie theatre and there it is, on Memorial Day, the air-conditioning is a great hit to all movie goers and Paramount not only made huge profit all years round, Carrier also made his big step forwards as he is appointed to install the climate control technology in 300 movie theaters over the next 5 years.

So this is how air conditioning is made known to the world through Movie Theaters.

"I fish only for edible fish, and hunt only for edible game even in the laboratory." - Willis Haviland Carrier on being practical.



Monday, April 25, 2011

Second life for plastics

All thanks to Discovery Science Channel, I learnt quite a lot these few days. One of them that I find it great is the second life of plastics as featured in the program called Eco-Life.

Plastic bottle making

As everyone knows, plastics is inevitable around us and in the material science that we studys every plastics are vulnerable to chemicals, temperature and toxicity. However, there are people still using plastic because ironically, industrial prefers plastic because of low energy cost, easy access to material and high productivity manufacturing as compared to other materials. It is although recyclable but in each lot, only 30% of recyclable plastics is allowed due to instability of the atomic strucure and properties.

In the show, it describes something that we have never noticed before in every plastic bottles. That is the SPI(Society of Plastic Industry) Resin Identification Code as specified in some labels or even on the body of the plastic bottle. This is denotes by three enclosing arrows with a number 1 or 2 in the center.

PET stands for Polyethylene Terephthalate. It is a thermoplastc polymer resin of the polyester family and is used in most plastic containers be it food, liquid and thermoforming applications.

There are 7 Resin Idenfication Code(RIC) and most commonly used are Code 1 and 2, which is commonly recycled because of its ease in forming and low heating requirement. however because of the low heaing properties, common drinking bottles are not recommended for hot water application especially to boiling water. Class 3 to class 7 are harder plastics and they can withstand higher heat.

According to Science Channel, one man who have concern on the plastic uses come out with an ingenious plan of mixing plastics. As fr as recycling is concern, plastics are best not to mix because of their different chemical structure. What he did is by engineering modification, he have managed to come up with a process that mix class 2 and class 5 plastics and bond them together with a special extrusion process that he has patented and the product becomes a construction material with strength high than steel itself. It can be used to construct bridges and these two class of plastic materials have their own advantages and disadvantages. For example class two has high ductility but low yield strength and low resistance to heat and chemical. whereas class 5 plastic has high yield strength, high resist to chemicals, heat and toughness but it is brittle. So in the special process it bond the two class of plastics together and create a new material suitable for construction in the form of I beam. So with the revolution of the plastics, metals expecially iron can be replaced wih plastics because of its high resistance to corrosion as what nature does.

Problem with plastics in drinking water bottle

In Engineering Material Science, every plastics has a temperature called glass temperature. This is the temperature where plastics is heated to a temperature to a point where it exist in both solid and liquified state. Suppose if a water it contains reached this temperature, polyester can leak into the water and create toxic if consumed. One of the commonly famous plastic toxic is Bisphenol commonly known as BPA. It is an important component of plastic water bottles, baby bottles, inner lining of food cans, microwave containers, and hundreds of common household and industrial products. The use of BPA-containing plastic in the packaging of food and beverages is alarming because there is a long list of health disorders attributed to the chemical.

If heated water is required for transportation, it is best to use bottles made of stainless steel even though studies have shown that the optimum container is glass bottles. Glass bottles can experience sudden explosion in the case of Vaccuum bottles. It breaks easily and non-recyclable. So if water container is required, use glass cup and be sure to hold the handle. If traveling around is required, use a double walled stainless steel bottle. Having no glass temperature as what plastic experiences, both glass and stainles steel melting point is at 1510 degree Celcius. This is 15 times more than boiling water temperature. Even if the water is superheated, it can reached to a maximum of 250 degree celcius which the stainless steel can holds. That is why stainless steel double walled insulated is best recommended for holding a hot water or cold water.

Although BPA is only lethal at very high doses, increasing scientific evidence suggests that it can disrupt key body functions at very low doses, and builds up in our bodies over time with each exposure. Despite the multiple scientific studies that clearly link BPA to developmental and other abnormalities in animals and humans, the US Food and Drug Administration (FDA) issued a statement on August 15, 2008 reaffirming the safety of products containing low levels of BPA. However, no mention is made of the effects of repeated exposure over many years, or of the effect of combinations of hormones and BPA.

There are billions of people around the world who drink water from plastic bottles every day. Unfortunately, bottled water is harmful to the environment, your wallet and your health. Ironically, people who buy bottled water in an effort to improve overall well-being are actually putting their health at risk. BPA and other toxic chemicals have been shown to leach out of both single-use and reusable plastic water bottles. Repeated use of plastic bottles has been shown to increase the rate of chemicals like BPA leaching out, especially bottles intended for single use.

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