If your answer is YES, this article is for you
Dr. Saliya Jayasekara.
Senior Lecturer Department of Mechanical Engineering
University of Moratuwa
Many passenger vehicles, including three-wheelers and motorcycles are fueled by octane 95 gasoline when octane 92 gasoline (petrol) is available at a lower price.
Otto engine (petrol engine) is an internal combustion spark ignition engine invented by a German engineer Nicolaus Otto in 1876 and used in most of the light weight vehicles including cars, three wheelers and motor bicycles. Otto engines can burn most of the hydrocarbon fuels (including hydrogen and ethanol) that can mix with air by evaporation (low boiling point). But the combustion characteristics of different hydrocarbons are not the same when burned inside an engine. If an Otto engine is designed for a particular fuel, it would not perform similarly with a fuel that has a different chemical composition.
In a well-tuned Otto engine run on gasoline for which the engine is designed, the combustion of the gasoline (petrol) / air mixture will continue smoothly from the spark plug to the piston head by igniting successive layers of the mixture as shown in Figure 1 (a).
If low grade gasolines are used, the combustion of some of the air/ fuel mixture in the cylinder does not result from propagation of the flame front initiated by the spark plug, but one or more pockets of air/fuel mixture explode (Detonate) outside the envelope of the normal combustion front as shown in Figure 1 (b). This detonation can cause severe damage to the piston and the head of the engine while deteriorating thermal performance of the engine (low efficiency)
Gasoline is a petroleum-derived product comprising a mixture of different hydrocarbons ranging from 4 to 12 carbon atoms in a carbon chain with the boiling point ranging of 30–225°C. It is predominantly a mixture of paraffins, naphthenes, aromatics and olefins. Additives and blending agents are added to improve the performance and stability of gasoline. The engine designers learned that straight-chain paraffin have a much higher tendency to detonate than do branched-chain paraffin.
The tendency of a particular gasoline to detonate is expressed by its octane number (ON). Arbitrarily, tri-methyl-pentane, C8H18 (iso-octane) is assigned an ON of 100, while the straight-chain paraffin n-heptane, C7H16 is given an ON of zero. Hence, a fuel sample with the same anti-detonation quality as that of a mixture containing 90% iso-octane and 10% n-heptane is said to have an ON of 90. Gasoline is made up of a mixture of mostly branched-chain paraffin with suitable additives to give an ON in the range 90 –100. It was also learned through experiments that the ON of a gasoline blends (e.g. gasoline and ethanol) can be calculated by using weighted average ON of each compound. Most importantly, the octane number has nothing to do with the heating value (Calorific value) or the purity of the fuel.
Engine thermodynamics show that engines with a high compression ratio offer higher thermal performance than engines with a low compression ratio. These engines having high compression ratio require high octane gasoline (for example octane 95) to avoid detonation. However, using gasoline having higher octane ratings for the engines designed for a low octane rating (for example, 92 octane) would not provide an additional benefit or loss, other than increased fuel cost.
Therefore, it is important to know the designed octane number of the engine before fueling (refer owner’s manual of the vehicle). For example: the minimum ON requirement for two and three wheelers in south Asia is 87 (The World Bank). Most of the Toyota, Honda and Nissan models including hybrid engines recommend 92 octane gasoline.
Dr. Saliya Jayasekara received the B. Sc. degree in mechanical engineering from university of Moratuwa in 2001, and the M.Sc. and PhD degrees in decentralized power generation systems from Royal institute of technology Sweden and the Melbourne University Australia in 2004 and 2013 respectively. He has well over 13 years of national and international experience in design and installation of centralised/decentralised power plants, boilers (utility/package) and heat exchangers. Currently he is serving as a senior lecture at University of Moratuwa, a visiting lecturer and fellow at Deakin University Australia.
The ‘Cheena Abhagya’ on the rise
There is a big China Hurry in the government that seems much higher than any hurry about controlling the Covid pandemic.
The debate of the Colombo Port City Commission was scheduled for May 5, without even receiving the Supreme Court decision on the many petitions filed before it. This is a complete and shameless shift from the very process of parliamentary debate, the stuff of democracy.
A debate in parliament is based on the material — the facts, plans, decisions, proposals etc – placed before the members. This government with its Vistas of Prosperity and Splendour has no interest in the democratic process. They decide on a date for a debate on what is the most important piece of legislation today, with the MPs not given even an hour to know and study the decision of the Supreme Court on the subject. In fact, it is also a huge insult to the Supreme Court and the judicial process, too.
This decision and its refusal to agree to the Opposition calls for more days for this debate, showed how the government is ready, and determined, to use its two-thirds majority, post 20A, to have no respect for the democratic process.
Although this shameful move by the government failed, due to the Supreme Court decision not reaching the Speaker by that time, the mockery of democracy continues, with the next date for the debate on the Port City subject being fixed for May 18, again with no opportunity for all MPs to read and study the court decision/s on so many matters raised by the petitioners, some of whom were members of parliament too.
This is the China Hurry – Cheena Hadissiya – being displayed, just the initial moves to use the Sinopharm Covid Vaccine on the people of this country, while it has not been approved by the WHO and the responsible Health and Medical officials in this country.
This is the ‘Cheenabhagya’ doing much more than the Saubhagya Dekma of Gotabhaya Power. A rising ‘Abhagya’ or misery to the people.
This Cheenabhagya is certainly impacting others in the government, such as Minister Gamini Lokuge, who decided to arbitrarily lift the lockdown and travel restrictions in Piliyandala. There will be much more Cheena benefits and power in the coming weeks, as the country keeps reeling with the spread of the latest variant of Covid-19.
The Cabinet move to import gyms to strengthen the muscles of the people is certainly a move to reduce the thinking power of the people. Muscle Power is the stuff of rulers who have no faith in the Brain Power of people, who would dare to question the decisions taken by rulers. The use of this Brain Power is the very substance of the Buddhist thinking that has been the core value of Sri Lanka through the centuries. This is the substance of the Buddha Dharmaya as against the Buddha-agama that has distorted Buddhist teachings. Are the plans to build a Sri Lankan temple, in the premises of the ancient and first Buddhist White Horse Temple in China, a show of the Cheena Dekma – or Chinese Vision – that holds sway among those attached to what will soon be the Cheena Rajavasala in Hambantota. Maybe, we will soon change the name of Hambantota to a Maha Cheenatota, and wipe off the arrival of Hamban people to this country.
Rishad Bathiuddin remains in the spotlight today. His moves with different governments, from the Mahinda Rajapaksa to the Yahapalana have been the cause of much criticism and court orders such as replanting torn down jungles. He is now detained as a terror suspect, and the Cheena Balaya does not want him to attend parliament. Sarath Weerasekera, Minister of Public Security, does not want him in the House, as he will violate the legal process that holds him in custody, as he would most likely reveal the secrets of terrorism inquiries supposedly now underway, and may even help other un-arrested terror suspects to flee the country. This is against the official thinking of the Attorney General, who certainly knows more about law, than a retired armed services officer.
The innocence of an unconvicted person until conviction by a court, is part of our democratic and judicial processes. Weerasekera is wholly pleased to have within the government ranks, in parliament, a person convicted by the courts for the crime of murder in the Ratnapura district, Premalal Jayasekera. Is this power prospect for future murderers, convicted by a court of law? This Cheena Havula also had in its ranks Sivanesathurai Chandrakanthan – Pillayan, while he was held in custody for the murder of a former MP in a Batticaloa church, many years ago. Well, well – he has since been acquitted and released by the Batticaloa High Court
It is not our delight that Rishard Bathiuddin is the focus of a call for democracy within parliament. We are aware of how his party, and the Muslim Congress too, gave support to pass the 20A, and its huge blow to democracy. But the rights of a citizen and an elected MP, have to be protected, whatever the politics and the other stuff of a person may be. To give him the right to attend and speak in parliament is a core value of the democratic process. This cannot be torn away under the Cheena thinking, which is fast taking us to the manipulations of the Chinese Communist Party, in its governance of China.
We are in the throes of a pandemic that is certainly sweeping the country. The need is to guide and handle the fight against it, and save the people of the horror we see just across the Palk Strait. Narendra Modi, who was honoured by his BJP for the so-called success in defeating Covid-19, is now facing humiliating defeats, electorally, socially and globally too. Our fight against this pandemic must be through the values of the democratic process. The values we have seen till 1977, after independence, which have been distorted and destroyed by JRJ and down to the Cheenabhagya of Gotabhaya.
The fight against Covid-19 must be a fight to restore Democracy too, in every form of the people’s rights and freedoms.
Let’s move to Janatha Bhagya, away from the rising Cheena Abhagya of today!
From Cylinder to Liquid Oxygen Plant
Story of Oxygen supply at National Hospital –
The National Hospital of Sri Lanka (NHSL) is the largest and best equipped Teaching Hospital in the country with a bed strength of nearly 4,000. It has 26 operating theatres, 28 Intensive Care Units (ICU) and several institutes including one for Cardiology housed in a large number of buildings. It is located on a 32-acre land standing in the middle of Colombo.
NHSL is circled by a ring of busy public roads while some roads are running through the premises. Hospital premises and surrounding roads are always filled with hurriedly pacing medical staff, siren blaring ambulances, patient-carrying trolleys, distressed relatives and tired visitors. One would not miss the sight of a cylinders loaded truck crawling across in this melee and wonder why the truck. They ensure continuous and uninterrupted supply of most essential medical oxygen for the patients treated in ICUs and those undergoing surgery in operating theatres.
A few years ago, a visitor would not have missed the outside walls of these operating theatres and ICUs each of which decorated with 6-7 hanging jumbo oxygen cylinders. When I made the morning strolls down the hospital corridors my eyes always caught the sight of these cylinders. Oxygen is taken through a copper tubing system fixed to these cylinders to the respective destinations. i.e. Oxygen outlet in the bedside of patients treated in ICUs and in operating theatres. Hospital had a sufficient number of cylinders filled with oxygen. Employees efficiently replaced empty cylinders with new ones.
Every day employees collected empty cylinders, loaded them on a truck and transported to the Oxygen Company in Mattakkuliya for refilling. On certain days when the oxygen consumption was high, this operation has to be doubled. Hospital had its own truck and a group of specially trained skilled employees assigned for the task. Loading and unloading of these jumbo cylinders was a specialised job.
I noticed this operation during my afternoon inspection tour. In fact, the noise made in loading unloading as well as dismounting and mounting cylinders on the walls and the sight itself, to say the least, was a nuisance. Once the truck returned, the refilled cylinders were immediately distributed among the theatres and ICUs. Needless to say this was a hectic task considering the large number, and the spread of theatres and ICUs in the hospital.
There were tensed situations when the truck did not return on time due to a break down, a traffic congestion or an accident on the way. Thought of the delay of the truck with refilled oxygen cylinders gave me many sleepless nights. I was waiting to welcome the irritating noise made when cylinders fell on one another during unloading. While others were cursing, I got a sense of relief as it was an indication that the oxygen truck has arrived. My official residence was in very close proximity to the Merchants Ward where many cylinders were unloaded. No sooner had I heard the clattering sound than I ran to the window to witness the unloading.
As the Director of the country’s largest hospital, I was responsible for the overall smooth functioning of the hospital itself and that of men, material and machinery. And among all, ensuring the continuous and uninterrupted supply of oxygen for patients who were critically ill and those undergoing surgery was foremost.
Majority staff including doctors and nurses did not know the complexity behind the smooth flow of oxygen through the outlet whenever they open the valve to administer oxygen to a patient. Only a handful of people knew the complexity of the ‘oxygen supply operation’ in the hospital. It was a nightmare for me personally and all my predecessors.
While worrying over this cumbersome complex manual operation, I was wondering how fitting this type of oxygen supply for a Teaching Hospital of the magnitude of the National Hospital. My mind was busy in exploring and weighing alternatives.
While listening to the clattering of cylinders and watching the swift movements of workers’ hands in the unloading operation in the middle of the night, with a cup of steaming coffee in my hand, a thought struck my mind. I heard my own voice shouting over the clattering sound of falling cylinders; Hey! Man, be practical, install a Liquid Oxygen Plant in the hospital premises itself.
Early next morning ignoring the supervision tour, I was busy preparing a comprehensive proposal to the Ministry of Health with a clear justification of the investment. Having submitted the proposal followed by a few telephone calls the Ministry responded by approving the proposal.
The proposal was designed to have a Liquid Oxygen Plant with the highest capacity for the hospital and another with less capacity dedicated for the Institute of Cardiology located a little away from the main hospital premises across the street.
A few moons later, a Liquid Oxygen Plant near Ward 13 and a separate smaller plant on the premises of Institute of Cardiology rose to the sky. The copper pipelines were laid connecting all the operating theatres, intensive care units and high dependency units which required continuous uninterrupted supply of oxygen. The project was completed within a matter of a few months providing a great sense of relief to me.
The company which installed the two oxygen tanks is attending to maintenance and repairs. The company regularly monitors the level of consumption and replenishes the tanks. The hospital staff need not intervene.
Needless to mention the relief it brought to me. It was in the year 2006 during which the Hospital installed the two oxygen plants. Since then we did not have to wait for the truck or bother about cylinders. There has not been any loading unloading or clattering of cylinders. I wanted to ensure that my successors would have a permanent reliable source of Oxygen supply for our patients and avoid sleepless nights unlike me and my predecessors.
After the COVID-19 pandemic Oxygen has become the mostly used word among the healthcare workers. After retirement today, I reminisce my time as the Director of NHSL and recall how the disturbed night dawned upon me the idea to install a Liquid Oxygen Plant to ensure the continuous supply of Oxygen to patients gasping for oxygen.
Our neighbouring India is losing thousands of young lives a day due to unavailability of Oxygen. I am happy about the forethought I had 15 years ago long before the term ‘COVID-19 Pandemic’ entered our vocabulary.
Boosting immune system to fight Covid-19: Is it possible?
By Saman Gunatilake
Emeritus Professor of Medicine
University of Sri Jayewardenepura
Immune boosting is a trending topic these days with the COVID-19 pandemic. The concept of “immune boosting” is scientifically misleading and often used to market unproven products and therapies. There is no current evidence that any product or practice will contribute to enhanced “immune boosting” protection against COVID-19. This lack of evidence has not stopped wellness gurus with vested interests, and commercial entities from propagating notions of boosting immunity. Internet and popular press are flooded with messages of this nature resulting in an abundance of misinformation circulating online. The public is increasingly going online for health information and questions persist around the kinds of inaccurate information the public is absorbing and the impacts it may be having on health-related decisions and actions.
What are Immunity Boosters?
Immunity boosters are products which claim to be able to support your immune system so you aren’t as likely to get sick. Additionally, if you do get sick, taking the supplements will make your illness pass faster. There is no scientific and clinical evidence in humans to support claims of ‘immunity boosting’ foods and other products which supposedly enhance immunity. The body has its own immune system which fights against viral and bacterial invaders. With a normal immune system, we are capable of protecting ourselves against most infections but with certain situations the infection manages to overcome our immune system and cause serious disease and even death. The current Covid 19 pandemic is such a situation. We are in the grip of a spike in infection with over 1000 cases per day seen during the last few days. Total deaths from the pandemic in our country is nearing 700 and the total cases up to now amounts to around 111,800.
With no scientifically established cure for Covid-19 yet and the available recommended treatments limited to severe cases and being not so effective, recovery in most cases has largely been reliant on the human body’s natural defence, the immune system. Fighting the infection by boosting our immune systems had been the buzzword since the beginning of the pandemic. This has led to many misconceptions, misinforming and misleading the public. Improving the diet, taking vitamins and herbal products, lifestyle changes are proposed as ways of doing this. As a result, the market has been flooded with an array of products that claim to boost one’s immunity.
One of the common misconceptions is that high doses vitamin supplements and other minerals and nutrients boost one’s immunity. Ayurvedic concoctions, fruit juices, vitamin pills, zinc tablets have flooded the market with an array of products that claim to boost one’s immunity. Promoters of these products indicate that the body’s natural defences can be strengthened or enhanced by the consumption of certain foods, herbal products or the use of specific products.
Is there robust scientific evidence to support these claims for immune system boosting? The answer is no. Immunology experts believe that there is no way for healthy adults to improve their immunity through foods or other products. The immune system is very complex and these claims about boosting immunity are irrational and unscientific.
The Immune System
The immune system is activated by things that enter the body that the body doesn’t recognise as its own such as bacteria, viruses or even particles that cause allergy, like food, drugs and pollen. Most pathogens have a surface protein on them that the immune system recognizes as foreign. These are called antigens. Then the immune system sets in motion a complex process that fights the invader – this is the immune response.
There are two kinds of immune responses in the human body. The innate immune response is the first to kick in and is common among all animals. It is non-specific and immune cells mount an immediate attack on antigens. The response is subsequently replaced by the adaptive immune response, which tailors defences based on the kind of pathogen that is being encountered. The innate immune response consists of white blood cells like neutrophils, macrophages, and monocytes, while the adaptive response involves Lymphocytes -T cells and B cells, as well as antibodies produced by these cells as a specific response to the invader’s antigens. Stimulated immune systems release chemical proteins known as pro-inflammatory cytokines in large numbers, which can cause soreness and pain. So boosting immunity may lead to unwanted inflammations causing swelling, redness and pain locally and fever and other organ damage.
The Internet searchers will find that the myth of “boosting immunity” is extremely pervasive. Of the approaches that claimed to boost immunity, the top ones were diet, fruit, vitamins, antioxidants, probiotics, minerals. Interestingly, vaccines, the only proven method that enhances our immune response to an infection is ranked very low. One of the biggest misconceptions is that consuming more vitamins than required helps the immune system. It has been proven, time and again, that mega-doses of Vitamin C or of any kind of vitamin are not effective on the body at all. Another misconception is that zinc tablets can play a role in mitigating Covid-19. However, this isn’t backed by evidence either.
Zinc is not an immunity booster. It is an essential mineral for the body which is a ‘cofactor’ for a large number of proteins and enzymes. A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme’s activity as a catalyst. Like zinc, vitamin C is also a cofactor, and is important for the body to function. So, if you have a deficiency of these essential micronutrients, you will face a problem. But, if a person does not have any such deficiency, an excess amount of these taken does not improve one’s chances of fighting off a virus. Vitamin C and Zinc deficiencies are very rare unless someone is starving or following an extreme diet depleted of nutrients. Iron and Iodine deficiencies are seen in communities and more than immune deficiency they cause other problems.
An extremely active immune system, can also be problematic. In severe Covid-19 cases, the body launches an aggressive immune response resulting in the release of a large amount of pro-inflammatory proteins. This is known as a cytokine storm and is one of the common causes of death in Covid-19 patients. A cytokine storm occurs when the body’s immune system goes into an overdrive, killing healthy cells and causing organ failures. Several research studies suggest that the cytokine storm causes lung injury and multi-organ failure. So, if this is the case boosting the immune system in a Covid patient is not a wise thing to do.
Market interests add to the myth
The truth is natural immunity in normal people cannot be improved. There are immunocompromised individuals with a poor immunity who are susceptible to infections due to certain illnesses, and how can they stay safe from this highly infectious virus that spreads rapidly? The most effective way is by keeping our communities safe.
We can do this by attending to the public hygiene of the population exposed to the infection. Providing safe drinking water, providing clean air, providing adequate nutrition — are ways of keeping the people healthy and strong to fight any infections. There are parts of our country fortunately not as bad in India, without access to these basic health requirements. Achieving social distancing in these communities that live in overcrowded households is impossible.
This background, and a new infection with no treatment, led to various interested parties with good and bad intentions in promoting the myth of immune boosting. They have become self-proclaimed experts exploiting this crisis, putting forth all kinds of miraculous non allopathic substitutions. As allopathic medications to be approved, a rigorous procedure has to be observed, they resorted to the easier approach of promoting quick remedies in traditional and herbal products. Unproven ‘natural’ remedies came to the fore in our country in this background where people felt helpless. The vaccine, the only proven way of boosting the immunity of an individual and the population against a specific disease was not available around this time.
There are added dangers in such situations. There may be a lot of drug-drug interactions. If people are consuming allopathic medicines, and then also start consuming these medicinal herbs, the components of the herb will interact with the drug resulting in unknown complications. These unapproved medications can have toxic effects on your kidney, liver and other organs.
Even during the Spanish Flu pandemic in 1918 companies jumped in on the opportunity to hail themselves as immunity boosting drug producers. However, no products were ever proven to be effective in improving immune responses.
Maintaining a normal immune system
A poor immune system is seen in people with certain ailments. Some are born with defects in their immune system and they are known as immunodeficiencies. People with chronic illnesses like diabetes and auto immune disorders are also vulnerable to catch illnesses easily as their immune systems are weak. People on immunosuppressant medications like steroids and cancer drugs also have a weakened immune system and easily catch infections and develop serious complications easily.
Lifestyle is key for keeping your immune system normal and ready to act with an adequate response when necessary. For now, there are no scientifically proven direct links between lifestyle, exercise and enhanced immune function. Researchers are exploring the effects of diet, exercise and stress on the immune response. There are indeed processes that do affect our immune cells and improve their responses. The best one of them, perhaps, is exercise. Many studies have shown that moderate exercise of less than 60 minutes can improve the circulation of anti-inflammatory cytokines, neutrophils, natural killer cells, T cells and B cells. This can work effectively — not for combating diseases at a specific point in time, but to combat stress hormones in general, which can suppress immune cell function. Extremely high intensity exercise leads to a short duration of compromised immunity, increasing risk for disease in this time period. This is one of the reasons marathon runners or professional sports persons tend to catch a fever or cold in the days following a sporting event. Regular exercise is known to improve cardiovascular health, lowers blood pressure, helps control body weight. Therefore, adopting general healthy-living strategies make sense since they are likely to have other proven health benefits. But whether they help to boost the immune system is a controversial issue with no proven answers.
The immune system can also be compromised by many lifestyle habits such as smoking, which is known to affect T and B cells, among a host of other parameters. Diseases like diabetes by themselves result in compromised immune systems. This is why diabetic patients are particularly susceptible to infections. Obesity is another condition with a weak immune system as it predisposes to the development of other illnesses like diabetes and hypertension. There appears to be a connection between poor nutrition and immunity and this is a problem especially in the elderly. Poor nutrition can lead to micronutrient malnutrition, in which a person becomes deficient in some essential vitamins and trace minerals. Deficiency of these can result in a poor immune response to infections. Older people tend to eat less and often have less variety in their food. In them dietary supplements may have some beneficial effects and they should discuss this with their doctors. Taking mega doses of vitamins do not help and can even be harmful.
Every part of your body, including your immune system that fights against infections function better when protected from unwanted damage and bolstered by healthy-living styles. These are – not smoking, taking a diet high in fruit and fibre, exercising regularly, maintaining a healthy weight, avoiding alcohol or consuming in moderation, getting adequate sleep, washing hands regularly, developing good food habits, minimizing stress.
However, there currently exists no evidence of any consumable foods or products being able to induce an improvement in immune function. Although some preparations have been found to alter some components of the immune system, so far there is no evidence that they actually boost your immunity to the point where you are protected against infection. The only scientifically proven way to boost immunity, the immune system, and an immune response is through vaccinations. Vaccines prime your immune system to fight off infections before they take hold in your body.
So, where do we stand today? Vaccines to boost our immunity against Covid, prevention of spread and catching infection by proper wearing of masks, washing hands and maintaining social distance. These are the scientifically proven methods and others appear to be market-driven myths.
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