Tuesday 25 March 2014

Worked on a farm till the age of 19, was recognized as FATHER OF GREEN REVOLUTION !!!

Norman Ernest Borlaug (March 25, 1914 – September 12, 2009) was an American biologisthumanitarian and Nobel laureate who has been called "the father of the Green Revolution", "agriculture's greatest spokesperson" and "The Man Who Saved A Billion Lives". He is one of seven people to have won the Nobel Peace Prize, the Presidential Medal of Freedom and the Congressional Gold Medal and was also awarded the Padma VibhushanIndia's second highest civilian honor.

Borlaug received his B.Sc. Biology 1937 and Ph.D. in plant pathology and genetics from the University of Minnesota in 1942. He took up an agricultural research position in Mexico, where he developed semi-dwarf, high-yielddisease-resistant wheat varietiesDuring the mid-20th century, Borlaug led the introduction of these high-yielding varieties combined with modern agricultural production techniques to Mexico, Pakistan, and India. As a result, Mexico became a net exporter of wheat by 1963. 

Between 1965 and 1970, wheat yields nearly doubled in Pakistan and India, greatly improving the food security in those nations. These collective increases in yield have been labeled the Green Revolution, and Borlaug is often credited with saving over a billion people worldwide from starvation. He was awarded the Nobel Peace Prize in 1970 in recognition of his contributions to world peace through increasing food supply. Later in his life, he helped apply these methods of increasing food production to Asia and Africa.

The eldest of four children; Borlaug was born to Henry Oliver (1889–1971) and Clara (Vaala) Borlaug (1888–1972) on his grandparents' farm in Saude in 1914. From age seven to nineteen, he worked on the 106-acre (43 ha) family farm west of ProtivinIowa, fishing, hunting, and raising corn, oats, timothy-grass, cattle, pigs and chickens. He attended the one-teacher, one-room New Oregon #8 rural school in Howard County, through eighth grade.

He attributed his decision to leave the farm and pursue further education to his grandfather, Nels Olson Borlaug (1859–1935), who strongly encouraged Borlaug's learning, once saying, "You're wiser to fill your head now if you want to fill your belly later on." Through a Depression-era program known as the National Youth Administration, he was able to enroll at the University of Minnesota in 1933. Borlaug failed the entrance exam, but was accepted to the school's newly created two-year General College. After two quarters, he transferred to the College of Agriculture's forestry program.

To finance his studies, Borlaug had to put his education on hold periodically to take a job. One of these jobs, in 1935, was as a leader in the Civilian Conservation Corps, working with the unemployed on U.S. federal projects. Many of the people who worked for him were starving. He later recalled, "I saw how food changed them ... All of this left scars on me". From 1935 to 1938, before and after receiving his Bachelor of Science in forestry in 1937, Borlaug worked for the United States Forest Service at stations in Massachusetts and Idaho. He spent one summer in the middle fork of Idaho's Salmon River, the most isolated piece of wilderness in the lower 48 states at the time.

In the last months of his undergraduate education, Borlaug attended a Sigma Xi lecture by Elvin Charles Stakman, a professor and soon-to-be head of the plant pathology group at the University of Minnesota. The event was pivotal for Borlaug's future. He had discovered that special plant breeding methods created plants resistant to rust. His research greatly interested Borlaug, and when Borlaug's job at the Forest Service was eliminated because of budget cuts, he asked Stakman if he should go into forest pathology. Stakman advised him to focus on plant pathology instead.

Borlaug subsequently enrolled at the University to study plant pathology under Stakman, receiving a Master of Science degree in 1940 and Ph.D. in plant pathology and genetics in 1942. Borlaug was a member of Alpha Gamma Rho fraternity.

The Cooperative Wheat Research Production Program, a joint venture by the Rockefeller Foundation and the Mexican Ministry of Agriculture, involved research in geneticsplant breeding, plant pathology, entomologyagronomysoil science, and cereal technology. The goal of the project was to boost wheat production in Mexico, which at the time was importing a large portion of its grain. During the sixteen years Borlaug remained with the project, he bred a series of remarkably successful high-yield, disease-resistant, semi-dwarf wheat.

Monday 24 March 2014

Arrested for participating in uprising; was the first one to liquefy gases !!




Karol Olszewski was born in borniszow near Tarnow.  Olszewski was a graduate of Kazimierz Brodziński High School in Tarnów (I Liceum Ogólnokształcące im. Kazimierza Brodzińskiego). He studied at Kraków's Jagiellonian University in the departments of mathematics and physics, and chemistry and biology. He carried out his first experiments using a personally improved compressor, compressing and condensing carbon dioxide. He took part in uprising in Poland and was arrested for his action and was imprisoned for several months.



In 1886, he entered the University of Krakow, as an assistant to the chemistry professor Czyrnianski. He succeeded in liquefying and solidifying carbon dioxide. He went to Heidelberg in 1872 where he studied uder Bunsen, Kirchoff and Blum. He received his degree "Insigni Cum Laude ". He returned to Krakow and met with Wroblewski, a newly appointed professor in physics. Karol's redesign of existing equipment allowed them to liquefy oxygen. April 9, 1883 a report was sent to the Academy of Science in Paris and is recognized as the date of the liquefaction of oxygen. Shortly after, the headstrong scientists parted company.


Olszewski defended his doctoral dissertation at Heidelberg University, then returned to Kraków, where he was made profesor nadzwyczajny (associate professor). In 1883, Zygmunt Wróblewski and Karol Olszewski were the first in the world to liquefy oxygen, nitrogen and carbon dioxide from the atmosphere in a stable state (not, as had been the case up to then, in a dynamic state in the transitional form as vapor). Chemist, physicist and expert of low temperatures; he also discovered a method of hydrogen liquefaction and constructed machinery for that purpose, which enabled him to reach the then-lowest world temperature, -225 C.


In 1895 he liquefied argon. He failed only to liquefy then-newly discovered helium. In 1896, on hearing of Wilhelm Röntgen's work with X-rays, within a few days in early February Olszewski replicated it, thus initiating the university's department of radiology.

Sunday 23 March 2014

Its World Meteorological Day !!!

World Meteorological Day is held annually on 23 March. The World Meteorological Organization (WMO) is an intergovernmental organization with a membership of 191 Member States and Territories. It originated from the International Meteorological Organization (IMO), which was founded in 1873. Established in 1950, WMO became the specialized agency of the United Nations for meteorology (weather and climate), operational hydrology and related geophysical sciences. It has its headquarters in Geneva, Switzerland, and is a member of the United Nations Development Group. The current Secretary-General is Michel Jarraud. The current president is David Grimes.

The World Meteorological Organization (WMO) is a specialized agency of the United Nations. It is the UN system's authoritative voice on the state and behavior of the Earth's atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resources.

WMO has a membership of 191 member states and territories, as of February 2014. The Convention of the World Meteorological Organization was signed 11 October 1947 and established upon ratification in 1950. WMO became the specialized agency of the United Nations in 1951 for meteorology (weather and climate), operational hydrology and related geophysical sciences. It originated from the International Meteorological Organization (IMO), which was founded in 1873.

The WMO hierarchy:
  • The World Meteorological Congress determines the policy of WMO and meets every four years. Each Member country is represented by a Permanent Representative with WMO. The Permanent Representative should be the director of the National Meteorological or Hydrometeorological Service.
  • The Executive Council (EC) implements Congress decisions and meets once a year.
  • Six regional associations for addressing regional concerns (see the section on regional associations, below)
  • Eight technical commissions provide technical recommendations for WMO and the national services.
  • The secretariat headed by the Secretary-General coordinates the activities of WMO with a regular staff of more than 250 employees.
Since its establishment, WMO has played a unique and powerful role in contributing to the safety and welfare of humanity. Under WMO leadership and within the framework of WMO programs, National Meteorological and Hydrological Services contribute substantially to the protection of life and property against natural disasters, to safeguarding the environment and to enhancing the economic and social well-being of all sectors of society in areas such as food security, water resources and transport.

The WMO and United Nations Environment Programme (UNEP) jointly created the Intergovernmental Panel on Climate Change (IPCC). It is also directly responsible for the creation of the Global Atmosphere Watch (GAW). The IPCC has received the Nobel Peace Prize in 2007 "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change."

WMO promotes cooperation in the establishment of networks for making meteorological, climatological, hydrological and geophysical observations, as well as the exchange, processing and standardization of related data, and assists technology transfer, training and research. WMO facilitates the free and unrestricted exchange of data and information, products and services in real- or near-real time on matters relating to safety and security of society, economic welfare and the protection of the environment. It contributes to policy formulation in these areas at national and international levels.

WMO plays a leading role in international efforts to monitor and protect the environment through its programs. In collaboration with other UN agencies and the National Meteorological and Hydrological Services, WMO supports the implementation of a number of environmental conventions and is instrumental in providing advice and assessments to governments on related matters. These activities contribute towards ensuring the sustainable development and well-being of nations.

Saturday 22 March 2014

College dropout, demoted employee & denied credit for his work; entertained us in our childhood with TOM & JERRY & other shows !


William Denby "Bill" Hanna (July 14, 1910 – March 22, 2001) was an American animator, director, producer, voice actor, and cartoon artist, whose film and television cartoon characters entertained millions of people for much of the 20th century. Hanna graduated from Compton High School in 1928. He briefly attended Compton City College but dropped out at the onset of the Great Depression.



After working odd jobs in the first months of the Depression, Hanna joined the Harman and Ising animation studio in 1930. During the 1930s, Hanna steadily gained skill and prominence while working on cartoons such as Captain and the Kids. In 1937, while working at Metro-Goldwyn-Mayer (MGM), Hanna met Joseph Barbera. The two men began a collaboration that was at first best known for producing Tom and Jerry and live action films


In 1957, they co-founded Hanna-Barbera, which became the most successful television animation studio in the business, producing programs such as The FlintstonesThe Huckleberry Hound ShowThe JetsonsScooby-DooThe Smurfs, and Yogi Bear. In 1967, Hanna–Barbera was sold to Taft Broadcasting for $12 million, but Hanna and Barbera remained heads of the company until 1991.

Hanna and Barbera won seven Academy Awards and eight Emmy Awards. Their cartoons have become cultural icons, and their cartoon characters have appeared in other media such as films, books, and toys. Hanna–Barbera's shows had a worldwide audience of over 300 million people in their 1960s heyday, and have been translated into more than 28 languages.

William Hanna was born to William John and Avice Joyce (Denby) Hanna in Melrose, New MexicoHe was the third of seven children and the only boy. When Hanna was three years old, the family moved to Baker City, Oregon, where his father worked on the Balm Creek Dam. It was here that Hanna developed his love of the outdoors. His interests also included sailing and singing in a barbershop quartetHanna studied both journalism and structural engineering at Compton City College, but had to drop out of college with the onset of the Great Depression.

After dropping out of college, Hanna worked briefly as a construction engineer and helped build the Pantages Theatre in Hollywood. He lost that job during the Great Depression and found another at a car wash. His sister's boyfriend encouraged him to apply for a job at Pacific Title and Art, which produced title cards for motion pictures. While working there, Hanna's talent for drawing became evident, and in 1930 he joined the Harman and Ising animation studio, which had created the Looney Tunes and Merrie Melodies series. Despite a lack of formal training, Hanna soon became head of their ink and paint department. Besides inking and painting, Hanna also wrote songs and lyrics. 

Hanna was given the opportunity to direct his first cartoon in 1936; the result was To Spring, part of the Harman-Ising Happy Harmonies series. Hanna was among the first people MGM hired away from Harman-Ising to their new cartoon studio. The seriescaptain and the kids did not do well; consequently, Hanna was demoted to a story man and the series was canceledHanna's desk at MGM was opposite that of Joseph Barbera. Hanna and Barbera worked alongside animation director Tex Avery, who had created Daffy Duck and Bugs Bunny for Warner Bros. and directed Droopy cartoons at MGM.


In 1940, Hanna and Barbera jointly directed Puss Gets the Boot, which was nominated for an Academy Award for Best (Cartoon) Short Subject. The studio wanted a diversified cartoon portfolio, so despite the success of Puss Gets the Boot, Hanna and Barbera's supervisor, Fred Quimby, did not want to produce more cat and mouse cartoons. Surprised by the success of Puss Gets the Boot, Hanna and Barbera ignored Quimby's resistance and continued developing the cat-and-mouse theme. 


By this time, however, Hanna wanted to return to working for Ising, to whom he felt very loyal. Hanna and Barbera met with Quimby, who discovered that although Ising had taken sole credit for producing Puss Gets the Boot, he never actually worked on it. Quimby then gave Hanna and Barbera permission to pursue their cat-and-mouse idea. The result was their most famous creation,Tom and Jerry. Quimby accepted each Academy Award for Tom and Jerry's without inviting Hanna and Barbera onstage.


The first offering from the Hanna Barbara company was The Ruff & Reddy Show. They soon established themselves with two successful television series: The Huckleberry Hound Show and The Yogi Bear Show. A 1960 survey showed that half of the viewers of Huckleberry Hound were adults. This prompted the company to create a new animated series, The Flintstones. The company later produced a space-age version of The Flintstones, known as The Jetsons. Although both shows reappeared in the 1970s and 1980s, The Flintstones was far more popular. 


By the late 1960s, Hanna–Barbera Productions was the most successful television animation studio in the business. The Hanna–Barbera studio produced over 3000 animated half-hour television shows. The Hanna–Barbera studio also produced Scooby-Doo (1969–1986) and The Smurfs (1981–1989). The company also produced animated specials based on Alice in Wonderland, Jack and the Beanstalk, Cyrano de Bergerac as well as the feature-length film Charlotte's Web.

Thursday 20 March 2014

Lost legs at fifteen, circumnavigated the globe and raised $26 million !!!



Richard Marvin Hansen (born 26 August 1957) is a Canadian Paralympian and a philanthropist for people with spinal cord injuries. Hansen is most famous for his Man In Motion World Tour. He was one of the final torchbearers in the 2010 Winter Olympics. He was profiled and spoke during the opening ceremony for the 2010 Winter Paralympics


Born in Port AlberniBritish Columbia, Rick Hansen grew up in Williams Lake, British Columbia. As a young athlete, he had won all-star awards in five sports. He was paralyzed at the age of 15 from being in the back of a truck with his friend, when suddenly the pick up truck swerved and hit a tree. He left the bed of the truck from the impact and received a spinal cord injury. He worked on rehabilitation, completed high school, then became the first student with a physical disability to graduate in physical education from the University of British Columbia. 



Hansen won national championships on wheelchair volleyball and wheelchair basketball teams. He went on to become a world class champion wheelchair marathoner and Paralympic athlete. He competed in wheelchair racing at both the 1980 and 1984 Summer Paralympics, winning a total of three gold, two silver, and one bronze medal. Hansen won 19 international wheelchair marathons, including three world championships. He also coached high school basketball and volleyball. Hansen had a very close relationship with his family, especially with his father and grandfather, with whom he enjoyed frequent fishing trips.



In 1980, fellow British Columbian and Canadian athlete Terry Fox, who had lost a leg to bone cancer, undertook the Marathon of Hope, intending to run across Canada from Newfoundland to Vancouver Island to raise awareness for cancer research. He made it from St. John's, Newfoundland, to Thunder Bay, Ontario, before a cancer recurrence forced him to stop, about half of the way through his journey. Inspired by Terry's courage, Hansen decided to undertake a similar journey for spinal cord injury research. But his planned path was far more ambitious: he planned to circle the world in his wheelchair.



He embarked on his Man in Motion World Tour on 21 March 1985 from Oakridge Mall in Vancouver. He progressed on a 26-month trek, logging more than 40,000 km through 34 countries on four continents before crossing Canada. He returned to Vancouver's BC Place Stadium to cheering crowds of thousands on 22 May 1987 after raising $26 million for spinal cord research and quality of life initiatives. Like Terry Fox, he was hailed as an international hero. He was profiled and spoke during the opening ceremony for the 2010 Winter Paralympics. Today, the wheelchair and many other items associated with the Man In Motion World Tour are preserved by the BC Sports Hall of Fame and Museum.



Heart of a Dragon  is the film based on Hansen's Man in Motion Tour. Over twenty years ago, Michael French flew with a film crew from Vancouver, British Columbia to Beijing and documented Hansen's entrance into Beijing with over 1 million Chinese heralding his arrival as a hero. The song "St. Elmo's Fire (Man in Motion)" was written in his honor by Canadian record producer and composer David Foster and British musician John Parr and performed by Parr for the soundtrack of the film St. Elmo's Fire. It reached #1 on the Billboard Hot 100 in theUnited States in September 1985.


 He was one of the final torchbearers in the 2010 Winter Olympics. Hansen is currently president and CEO of the Rick Hansen Foundation, which has generated more than $200 million for spinal cord injury-related programs.

Wednesday 19 March 2014

Arguably these guys made WRITING IN MOVEMENT" possible and had much better technology then that of EDISON !!!


The Lumière Auguste Marie Louis Nicolas (19 October 1862, BesançonFrance – 10 April 1954, Lyon) and Louis Jean (5 October 1864, BesançonFrance – 6 June 1948, Bandol), were the earliest filmmakers in history. Appropriately, "lumière" translates as "light" in English. The Lumière brothers were born in BesançonFrance, in 1862 and 1864, and moved to Lyon in 1870, where both attended La Martiniere, the largest technical school in Lyon. Their father, Claude-Antoine Lumière (1840–1911),ran a photographic firm and both brothers worked for him: Louis as a physicist and Auguste as a manager. Louis had made some improvements to the still-photograph process, the most notable being the dry-plate process, which was a major step towards moving images.



It is said that, due to a lack of fee, Bouly was not able to pay the rent for his patent the following year, and Auguste and Louis Lumière's engineers bought the license. Louis Lumière worked with his brother Auguste to create a motion picture camera superior to Edison’s kinetoscope. The Lumières endeavored to correct the flaws they perceived in the kinetoscope to create a machine capable of both sharper images and better illumination.

cinematograph is a motion picture film camera, which also serves as a film projector and developer. There is much dispute as to the identity of its inventor. Some argue that the device was first invented and patented as "Cinématographe Léon Bouly" by French inventor Léon Bouly on February 12, 1892. Leon Bouly coined the term “cinematograph”, which translates in Greek to “writing in movement”


It was not until their father retired in 1892 that the brothers began to create moving pictures. They patented a number of significant processes leading up to their film camera, most notably film perforations (originally implemented by Emile Reynaud) as a means of advancing the film through the camera and projector. The original cinématographe had been patented by Léon Guillaume Bouly on 12 February 1892. The brothers patented their own version on 13 February 1895. The first footage ever to be recorded using it was recorded on March 19, 1895. This first film shows workers leaving the Lumière factory.

The Lumières held their first private screening of projected motion pictures in 1895. Their first public screening of films at which admission was charged was held on December 28, 1895, at Salon Indien du Grand Café in Paris. This history-making presentation featured ten short films, including their first film, Sortie des Usines Lumière à Lyon (Workers Leaving the Lumière Factory). Each film is 17 meters long, which, when hand cranked through a projector, runs approximately 50 seconds.


It is believed their first film was actually recorded that same year (1895) with Léon Bouly's cinématographe device, which was patented the previous year. The cinématographe — a three-in-one device that could record, develop, and project motion pictures — was further developed by the Lumières. The Lumières went on tour with the cinématographe in 1896, visiting BombayLondonMontrealNew York and Buenos Aires.


The Lumière Brothers were not the only ones to claim the title of the first cinematographers. The scientific chronophotography devices developed by Eadweard MuybridgeÉtienne-Jules Marey andOttomar Anschütz in the 1880s were able to produce moving photographs, as was William Friese-Greene's 'chronophotographic' system, demonstrated in 1890, and Thomas Edison'sKinetoscope, premiered in 1891. 

Since 1892, the projected drawings of Émile Reynaud's Théâtre Optique were attracting Paris crowds to the Museé Grevin. Louis Le Prince and Claude Mechanthad been shooting moving picture sequences on paper film as soon as 1888, but had never performed a public demonstration. Polish inventor, Kazimierz Prószyński had built his camera and projecting device, called Pleograph, in 1894.

Although the Lumière brothers were not the first inventors to develop techniques to create motion pictures, they are often credited as among the first inventors of the technology for Cinema as a mass medium, and are among the first who understood how to use it. 

Tuesday 18 March 2014

The Book binder's son who invented Diesel engine vanished like air and was never found !!!


Rudolf Christian Karl Diesel (March 18, 1858 – September 29, 1913) was a German inventor and mechanical engineer, famous for the invention of the diesel engine. Diesel was born in Paris, France in 1858, the second of three children of Elise (born Strobel) and Theodor Diesel. His parents were Bavarian immigrants living in Paris.Theodor Diesel, a bookbinder by trade, left his home town of Augsburg, Bavaria, in 1848. Rudolf Diesel spent his early childhood in France, but as a result of the outbreak of the Franco-Prussian War in 1870, his family (as were many other Germans) was forced to leave. They settled in London, England. 



Before the war's end, however, Diesel's mother sent 12-year-old Rudolf to Augsburg to live with his aunt and uncle, Barbara and Christoph Barnickel, to become fluent in German and to visit the Königliche Kreis-Gewerbsschule (Royal County Trade School), where his uncle taught mathematics.



At age 14, Rudolf wrote a letter to his parents stating that he wanted to become an engineer. After finishing his basic education at the top of his class in 1873, he enrolled at the newly founded Industrial School of Augsburg. Two years later, he received a merit scholarship from the Royal Bavarian Polytechnic of Munich, which he accepted against the wishes of his parents, who would rather have seen him start to work.



Diesel was unable to be graduated with his class in July 1879 because he fell ill with typhoid. While waiting for the next examination date, he gained practical engineering experience at the Gebrüder Sulzer Maschinenfabrik (Sulzer Brothers Machine Works) in Winterthur, Switzerland. Diesel was graduated in January 1880 with highest academic honours and returned to Paris, where he assisted his former Munich professor, Carl von Linde, with the design and construction of a modern refrigeration and ice plant. Diesel became the director of the plant one year later. In 1883, Diesel married Martha Flasche, and continued to work for Linde, gaining numerous patents in both Germany and France.



As he was not allowed to use the patents he developed while an employee of Linde's for his own purposes, he expanded beyond the field of refrigeration. He first worked with steam, his research into thermal efficiency and fuel efficiency leading him to build a steam engine using ammonia vapour. During tests, however, the engine exploded and almost killed him. He spent many months in a hospital, followed by health and eyesight problems. He then began designing an engine based on the Carnot cycle, and in 1893, soon after Karl Benz was granted a patent for his invention of the motor car in 1886, Diesel published a treatise entitled "Theory and Construction of a Rational Heat-engine to Replace the Steam Engine and Combustion Engines Known Today" and formed the basis for his work on and invention of the diesel engine.


Eventually, he obtained a patent for his design for a compression-ignition engine. In his engine, fuel was injected at the end of compression and the fuel was ignited by the high temperature resulting from compression. From 1893 to 1897, Heinrich von Buz, director of MAN AG in Augsburg, gave Rudolf Diesel the opportunity to test and develop his ideas. Rudolf Diesel obtained patents for his design in Germany and other countries, including the U.S. (U.S. Patent 542,846 and U.S. Patent 608,845).


In the evening of September 29, 1913, Diesel boarded the post office steamer Dresden in Antwerp on his way to a meeting of the Consolidated Diesel Manufacturing company in London. He took dinner on board the ship and then retired to his cabin at about 10 p.m., leaving word to be called the next morning at 6:15 a.m. His cabin was found empty during a roll call, and he was never seen alive again. A search of his cabin revealed that Diesel's bed had not been slept in, although his nightshirt was neatly laid out and his watch had been left where he could see it from the bed. His hat and overcoat were discovered neatly folded beneath the afterdeck railing.



In the foreword to a book titled Diesel Engines for Land and Marine Work, Rudolf Diesel states, "In 1900 a small Diesel engine was exhibited by the Otto company which, on the suggestion of the French Government, was run on Arachide oil, and operated so well that very few people were aware of the fact. The motor was built for ordinary oils, and without any modification was run on vegetable oil." Diesel went on to say that "I have recently repeated these experiments on a large scale with full success and entire confirmation of the results formerly obtained."



The diesel engine (also known as a compression-ignition engine) is an internal combustion engine that uses the heat of compression to initiate ignition and burn the fuel that has been injected into the combustion chamber. This contrasts with spark-ignition engines such as a petrol engine(gasoline engine) or gas engine (using a gaseous fuel as opposed to gasoline), which use a spark plug to ignite an air-fuel mixture.



The diesel engine has the highest thermal efficiency of any standard internal or external combustion engine due to its very high compression ratio. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) can have a thermal efficiency that exceeds 50%. Diesel engines are manufactured in two-stroke and four-stroke versions. They were originally used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in submarines and ships. Use in locomotives, trucks, heavy equipment and electric generating plants followed later.