Central Mechanical Engineering Research Institute

Are you a researcher?

Create a profile to get free access to personal recommendations for colleagues and new articles.

Central Mechanical Engineering Research Institute

Short name

CMERI

Country, city

India, Durgapur

059h0ng81

Organization website

Publications

1 757

Citations

40 531

h-index

Top-3 journals

Lecture Notes in Mechanical Engineering (46 publications)

Dalton Transactions (31 publications)

RSC Advances (29 publications)

Top-3 organizations

National Institute of Technology Durgapur (289 publications)

Indian Institute of Technology Kharagpur (120 publications)

Jadavpur University (83 publications)

Top-3 foreign organizations

Chonbuk National University (46 publications)

University of Erlangen–Nuremberg (22 publications)

Korea Institute of Science and Technology (17 publications)

Most cited in 5 years

Found

Publication title

Publisher

Journal

Field of science

Countries

Found

Since 1969

Total publications

1757

Total citations

40531

Citations per publication

23.07

Average publications per year

30.82

Average authors per publication

4.2

h-index

Metrics description

h-index

A scientist has an h-index if h of his N publications are cited at least h times each, while the remaining (N - h) publications are cited no more than h times each.

https://www.pnas.org/doi/full/10.1073/pnas.0507655102

Top-30

Fields of science

	50 100 150 200 250 300 350
Mechanical Engineering	Mechanical Engineering, 346, 19.69% Mechanical Engineering 346 publications, 19.69%
Condensed Matter Physics	Condensed Matter Physics, 251, 14.29% Condensed Matter Physics 251 publications, 14.29%
General Materials Science	General Materials Science, 233, 13.26% General Materials Science 233 publications, 13.26%
General Chemistry	General Chemistry, 212, 12.07% General Chemistry 212 publications, 12.07%
Mechanics of Materials	Mechanics of Materials, 212, 12.07% Mechanics of Materials 212 publications, 12.07%
Materials Chemistry	Materials Chemistry, 194, 11.04% Materials Chemistry 194 publications, 11.04%
Industrial and Manufacturing Engineering	Industrial and Manufacturing Engineering, 187, 10.64% Industrial and Manufacturing Engineering 187 publications, 10.64%
Electrical and Electronic Engineering	Electrical and Electronic Engineering, 148, 8.42% Electrical and Electronic Engineering 148 publications, 8.42%
General Chemical Engineering	General Chemical Engineering, 130, 7.4% General Chemical Engineering 130 publications, 7.4%
Physical and Theoretical Chemistry	Physical and Theoretical Chemistry, 118, 6.72% Physical and Theoretical Chemistry 118 publications, 6.72%
Computer Science Applications	Computer Science Applications, 101, 5.75% Computer Science Applications 101 publications, 5.75%
Surfaces, Coatings and Films	Surfaces, Coatings and Films, 96, 5.46% Surfaces, Coatings and Films 96 publications, 5.46%
Metals and Alloys	Metals and Alloys, 91, 5.18% Metals and Alloys 91 publications, 5.18%
Electronic, Optical and Magnetic Materials	Electronic, Optical and Magnetic Materials, 88, 5.01% Electronic, Optical and Magnetic Materials 88 publications, 5.01%
Renewable Energy, Sustainability and the Environment	Renewable Energy, Sustainability and the Environment, 85, 4.84% Renewable Energy, Sustainability and the Environment 85 publications, 4.84%
Inorganic Chemistry	Inorganic Chemistry, 84, 4.78% Inorganic Chemistry 84 publications, 4.78%
General Medicine	General Medicine, 76, 4.33% General Medicine 76 publications, 4.33%
Energy Engineering and Power Technology	Energy Engineering and Power Technology, 76, 4.33% Energy Engineering and Power Technology 76 publications, 4.33%
General Engineering	General Engineering, 67, 3.81% General Engineering 67 publications, 3.81%
Ceramics and Composites	Ceramics and Composites, 62, 3.53% Ceramics and Composites 62 publications, 3.53%
Catalysis	Catalysis, 57, 3.24% Catalysis 57 publications, 3.24%
Control and Systems Engineering	Control and Systems Engineering, 57, 3.24% Control and Systems Engineering 57 publications, 3.24%
General Physics and Astronomy	General Physics and Astronomy, 56, 3.19% General Physics and Astronomy 56 publications, 3.19%
Instrumentation	Instrumentation, 53, 3.02% Instrumentation 53 publications, 3.02%
Applied Mathematics	Applied Mathematics, 53, 3.02% Applied Mathematics 53 publications, 3.02%
Fluid Flow and Transfer Processes	Fluid Flow and Transfer Processes, 52, 2.96% Fluid Flow and Transfer Processes 52 publications, 2.96%
Atomic and Molecular Physics, and Optics	Atomic and Molecular Physics, and Optics, 49, 2.79% Atomic and Molecular Physics, and Optics 49 publications, 2.79%
Software	Software, 49, 2.79% Software 49 publications, 2.79%
Environmental Chemistry	Environmental Chemistry, 44, 2.5% Environmental Chemistry 44 publications, 2.5%
Fuel Technology	Fuel Technology, 42, 2.39% Fuel Technology 42 publications, 2.39%
	50 100 150 200 250 300 350

Journals

Publishers

	100 200 300 400 500 600
Elsevier	Elsevier, 550, 31.3% Elsevier 550 publications, 31.3%
Springer Nature	Springer Nature, 433, 24.64% Springer Nature 433 publications, 24.64%
Royal Society of Chemistry (RSC)	Royal Society of Chemistry (RSC), 148, 8.42% Royal Society of Chemistry (RSC) 148 publications, 8.42%
Taylor & Francis	Taylor & Francis, 112, 6.37% Taylor & Francis 112 publications, 6.37%
Wiley	Wiley, 93, 5.29% Wiley 93 publications, 5.29%
American Chemical Society (ACS)	American Chemical Society (ACS), 91, 5.18% American Chemical Society (ACS) 91 publications, 5.18%
SAGE	SAGE, 53, 3.02% SAGE 53 publications, 3.02%
IOP Publishing	IOP Publishing, 35, 1.99% IOP Publishing 35 publications, 1.99%
Inderscience Publishers	Inderscience Publishers, 30, 1.71% Inderscience Publishers 30 publications, 1.71%
Institute of Electrical and Electronics Engineers (IEEE)	Institute of Electrical and Electronics Engineers (IEEE), 26, 1.48% Institute of Electrical and Electronics Engineers (IEEE) 26 publications, 1.48%
ASME International	ASME International, 24, 1.37% ASME International 24 publications, 1.37%
AIP Publishing	AIP Publishing, 22, 1.25% AIP Publishing 22 publications, 1.25%
Emerald	Emerald, 17, 0.97% Emerald 17 publications, 0.97%
Begell House	Begell House, 13, 0.74% Begell House 13 publications, 0.74%
MDPI	MDPI, 11, 0.63% MDPI 11 publications, 0.63%
World Scientific	World Scientific, 8, 0.46% World Scientific 8 publications, 0.46%
Hindawi Limited	Hindawi Limited, 7, 0.4% Hindawi Limited 7 publications, 0.4%
Institution of Engineering and Technology (IET)	Institution of Engineering and Technology (IET), 6, 0.34% Institution of Engineering and Technology (IET) 6 publications, 0.34%
Pleiades Publishing	Pleiades Publishing, 5, 0.28% Pleiades Publishing 5 publications, 0.28%
Thomas Telford	Thomas Telford, 5, 0.28% Thomas Telford 5 publications, 0.28%
Cambridge University Press	Cambridge University Press, 4, 0.23% Cambridge University Press 4 publications, 0.23%
IOS Press	IOS Press, 4, 0.23% IOS Press 4 publications, 0.23%
Trans Tech Publications	Trans Tech Publications, 3, 0.17% Trans Tech Publications 3 publications, 0.17%
Optica Publishing Group	Optica Publishing Group, 3, 0.17% Optica Publishing Group 3 publications, 0.17%
American Scientific Publishers	American Scientific Publishers, 3, 0.17% American Scientific Publishers 3 publications, 0.17%
American Physical Society (APS)	American Physical Society (APS), 3, 0.17% American Physical Society (APS) 3 publications, 0.17%
The Korean Society of Precision Engineering	The Korean Society of Precision Engineering, 3, 0.17% The Korean Society of Precision Engineering 3 publications, 0.17%
Walter de Gruyter	Walter de Gruyter, 2, 0.11% Walter de Gruyter 2 publications, 0.11%
Korean Society of Mechanical Engineers	Korean Society of Mechanical Engineers, 2, 0.11% Korean Society of Mechanical Engineers 2 publications, 0.11%
Frontiers Media S.A.	Frontiers Media S.A., 2, 0.11% Frontiers Media S.A. 2 publications, 0.11%
	100 200 300 400 500 600

With other organizations

With foreign organizations

	5 10 15 20 25 30 35 40 45 50
Chonbuk National University	Chonbuk National University, 46, 2.62% Chonbuk National University 46 publications, 2.62%
University of Erlangen–Nuremberg	University of Erlangen–Nuremberg, 22, 1.25% University of Erlangen–Nuremberg 22 publications, 1.25%
Korea Institute of Science and Technology	Korea Institute of Science and Technology, 17, 0.97% Korea Institute of Science and Technology 17 publications, 0.97%
Hanyang University	Hanyang University, 12, 0.68% Hanyang University 12 publications, 0.68%
King Abdulaziz University	King Abdulaziz University, 9, 0.51% King Abdulaziz University 9 publications, 0.51%
King Fahd University of Petroleum and Minerals	King Fahd University of Petroleum and Minerals, 8, 0.46% King Fahd University of Petroleum and Minerals 8 publications, 0.46%
University of Ilorin	University of Ilorin, 7, 0.4% University of Ilorin 7 publications, 0.4%
Mechanical Engineering Research Institute of Russian Academy of Sciences	Mechanical Engineering Research Institute of Russian Academy of Sciences, 6, 0.34% Mechanical Engineering Research Institute of Russian Academy of Sciences 6 publications, 0.34%
King Saud University	King Saud University, 6, 0.34% King Saud University 6 publications, 0.34%
Pusan National University	Pusan National University, 6, 0.34% Pusan National University 6 publications, 0.34%
Cumhuriyet University	Cumhuriyet University, 5, 0.28% Cumhuriyet University 5 publications, 0.28%
Southwest Petroleum University	Southwest Petroleum University, 5, 0.28% Southwest Petroleum University 5 publications, 0.28%
Royal Melbourne Institute of Technology	Royal Melbourne Institute of Technology, 5, 0.28% Royal Melbourne Institute of Technology 5 publications, 0.28%
Korea Advanced Institute of Science and Technology	Korea Advanced Institute of Science and Technology, 5, 0.28% Korea Advanced Institute of Science and Technology 5 publications, 0.28%
Jagiellonian University	Jagiellonian University, 5, 0.28% Jagiellonian University 5 publications, 0.28%
Meijo University	Meijo University, 5, 0.28% Meijo University 5 publications, 0.28%
Louisiana State University	Louisiana State University, 5, 0.28% Louisiana State University 5 publications, 0.28%
University of Aveiro	University of Aveiro, 5, 0.28% University of Aveiro 5 publications, 0.28%
Aalto University	Aalto University, 4, 0.23% Aalto University 4 publications, 0.23%
Massachusetts Institute of Technology	Massachusetts Institute of Technology, 4, 0.23% Massachusetts Institute of Technology 4 publications, 0.23%
University of Johannesburg	University of Johannesburg, 4, 0.23% University of Johannesburg 4 publications, 0.23%
Missouri University of Science and Technology	Missouri University of Science and Technology, 4, 0.23% Missouri University of Science and Technology 4 publications, 0.23%
University of Minnesota	University of Minnesota, 4, 0.23% University of Minnesota 4 publications, 0.23%
Northumbria University	Northumbria University, 4, 0.23% Northumbria University 4 publications, 0.23%
Cranfield University	Cranfield University, 4, 0.23% Cranfield University 4 publications, 0.23%
University of Pittsburgh	University of Pittsburgh, 4, 0.23% University of Pittsburgh 4 publications, 0.23%
University of Bayreuth	University of Bayreuth, 3, 0.17% University of Bayreuth 3 publications, 0.17%
Dongguan University of Technology	Dongguan University of Technology, 3, 0.17% Dongguan University of Technology 3 publications, 0.17%
SLAC National Accelerator Laboratory	SLAC National Accelerator Laboratory, 3, 0.17% SLAC National Accelerator Laboratory 3 publications, 0.17%
Stanford University	Stanford University, 3, 0.17% Stanford University 3 publications, 0.17%
	5 10 15 20 25 30 35 40 45 50

With other countries

	10 20 30 40 50 60 70 80 90
Republic of Korea	Republic of Korea, 84, 4.78% Republic of Korea 84 publications, 4.78%
USA	USA, 52, 2.96% USA 52 publications, 2.96%
Germany	Germany, 43, 2.45% Germany 43 publications, 2.45%
Saudi Arabia	Saudi Arabia, 25, 1.42% Saudi Arabia 25 publications, 1.42%
China	China, 18, 1.02% China 18 publications, 1.02%
United Kingdom	United Kingdom, 18, 1.02% United Kingdom 18 publications, 1.02%
Japan	Japan, 18, 1.02% Japan 18 publications, 1.02%
Australia	Australia, 10, 0.57% Australia 10 publications, 0.57%
France	France, 9, 0.51% France 9 publications, 0.51%
Nigeria	Nigeria, 8, 0.46% Nigeria 8 publications, 0.46%
Poland	Poland, 8, 0.46% Poland 8 publications, 0.46%
Malaysia	Malaysia, 7, 0.4% Malaysia 7 publications, 0.4%
Turkey	Turkey, 6, 0.34% Turkey 6 publications, 0.34%
Portugal	Portugal, 5, 0.28% Portugal 5 publications, 0.28%
Finland	Finland, 5, 0.28% Finland 5 publications, 0.28%
South Africa	South Africa, 5, 0.28% South Africa 5 publications, 0.28%
Russia	Russia, 4, 0.23% Russia 4 publications, 0.23%
Belgium	Belgium, 4, 0.23% Belgium 4 publications, 0.23%
Spain	Spain, 4, 0.23% Spain 4 publications, 0.23%
Egypt	Egypt, 3, 0.17% Egypt 3 publications, 0.17%
Israel	Israel, 3, 0.17% Israel 3 publications, 0.17%
Iraq	Iraq, 2, 0.11% Iraq 2 publications, 0.11%
Canada	Canada, 2, 0.11% Canada 2 publications, 0.11%
Netherlands	Netherlands, 2, 0.11% Netherlands 2 publications, 0.11%
UAE	UAE, 2, 0.11% UAE 2 publications, 0.11%
Romania	Romania, 2, 0.11% Romania 2 publications, 0.11%
Singapore	Singapore, 2, 0.11% Singapore 2 publications, 0.11%
Czech Republic	Czech Republic, 2, 0.11% Czech Republic 2 publications, 0.11%
Algeria	Algeria, 1, 0.06% Algeria 1 publication, 0.06%
	10 20 30 40 50 60 70 80 90

We do not take into account publications without a DOI.
Statistics recalculated daily.
Publications published earlier than 1969 are ignored in the statistics.
The horizontal charts show the 30 top positions.
Journals quartiles values are relevant at the moment.

Science degree

Academy membership

Research interests

Skills

	5 10 15 20 25 30 35 40 45 50
Lecture Notes in Mechanical Engineering	Lecture Notes in Mechanical Engineering, 46, 2.62% Lecture Notes in Mechanical Engineering 46 publications, 2.62%
Dalton Transactions	Dalton Transactions, 31, 1.76% Dalton Transactions 31 publications, 1.76%
RSC Advances	RSC Advances, 29, 1.65% RSC Advances 29 publications, 1.65%
Materials Today: Proceedings	Materials Today: Proceedings, 23, 1.31% Materials Today: Proceedings 23 publications, 1.31%
Journal of The Institution of Engineers (India): Series C	Journal of The Institution of Engineers (India): Series C, 23, 1.31% Journal of The Institution of Engineers (India): Series C 23 publications, 1.31%
Numerical Heat Transfer; Part A: Applications	Numerical Heat Transfer; Part A: Applications, 20, 1.14% Numerical Heat Transfer; Part A: Applications 20 publications, 1.14%
International Journal of Advanced Manufacturing Technology	International Journal of Advanced Manufacturing Technology, 20, 1.14% International Journal of Advanced Manufacturing Technology 20 publications, 1.14%
Journal of Materials Chemistry A	Journal of Materials Chemistry A, 18, 1.02% Journal of Materials Chemistry A 18 publications, 1.02%
Journal of Materials Engineering and Performance	Journal of Materials Engineering and Performance, 16, 0.91% Journal of Materials Engineering and Performance 16 publications, 0.91%
Springer Tracts in Mechanical Engineering	Springer Tracts in Mechanical Engineering, 16, 0.91% Springer Tracts in Mechanical Engineering 16 publications, 0.91%
New Journal of Chemistry	New Journal of Chemistry, 15, 0.85% New Journal of Chemistry 15 publications, 0.85%
Inorganica Chimica Acta	Inorganica Chimica Acta, 15, 0.85% Inorganica Chimica Acta 15 publications, 0.85%
ChemistrySelect	ChemistrySelect, 15, 0.85% ChemistrySelect 15 publications, 0.85%
IOP Conference Series: Materials Science and Engineering	IOP Conference Series: Materials Science and Engineering, 15, 0.85% IOP Conference Series: Materials Science and Engineering 15 publications, 0.85%
Sadhana - Academy Proceedings in Engineering Sciences	Sadhana - Academy Proceedings in Engineering Sciences, 15, 0.85% Sadhana - Academy Proceedings in Engineering Sciences 15 publications, 0.85%
International Journal of Heat and Mass Transfer	International Journal of Heat and Mass Transfer, 15, 0.85% International Journal of Heat and Mass Transfer 15 publications, 0.85%
ACS Applied Energy Materials	ACS Applied Energy Materials, 14, 0.8% ACS Applied Energy Materials 14 publications, 0.8%
Journal of Molecular Liquids	Journal of Molecular Liquids, 14, 0.8% Journal of Molecular Liquids 14 publications, 0.8%
Journal of Failure Analysis and Prevention	Journal of Failure Analysis and Prevention, 14, 0.8% Journal of Failure Analysis and Prevention 14 publications, 0.8%
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture	Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 14, 0.8% Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 14 publications, 0.8%
Journal of Molecular Catalysis A Chemical	Journal of Molecular Catalysis A Chemical, 13, 0.74% Journal of Molecular Catalysis A Chemical 13 publications, 0.74%
Measurement: Journal of the International Measurement Confederation	Measurement: Journal of the International Measurement Confederation, 12, 0.68% Measurement: Journal of the International Measurement Confederation 12 publications, 0.68%
Physical Chemistry Chemical Physics	Physical Chemistry Chemical Physics, 11, 0.63% Physical Chemistry Chemical Physics 11 publications, 0.63%
Composites Part B: Engineering	Composites Part B: Engineering, 11, 0.63% Composites Part B: Engineering 11 publications, 0.63%
Journal of the Brazilian Society of Mechanical Sciences and Engineering	Journal of the Brazilian Society of Mechanical Sciences and Engineering, 11, 0.63% Journal of the Brazilian Society of Mechanical Sciences and Engineering 11 publications, 0.63%
Renewable and Sustainable Energy Reviews	Renewable and Sustainable Energy Reviews, 11, 0.63% Renewable and Sustainable Energy Reviews 11 publications, 0.63%
Heat Transfer Engineering	Heat Transfer Engineering, 11, 0.63% Heat Transfer Engineering 11 publications, 0.63%
Journal of Materials Processing Technology	Journal of Materials Processing Technology, 10, 0.57% Journal of Materials Processing Technology 10 publications, 0.57%
ACS applied materials & interfaces	ACS applied materials & interfaces, 10, 0.57% ACS applied materials & interfaces 10 publications, 0.57%
Transactions of the Indian Institute of Metals	Transactions of the Indian Institute of Metals, 10, 0.57% Transactions of the Indian Institute of Metals 10 publications, 0.57%
	5 10 15 20 25 30 35 40 45 50

	50 100 150 200 250 300
National Institute of Technology Durgapur	National Institute of Technology Durgapur, 289, 16.45% National Institute of Technology Durgapur 289 publications, 16.45%
Indian Institute of Technology Kharagpur	Indian Institute of Technology Kharagpur, 120, 6.83% Indian Institute of Technology Kharagpur 120 publications, 6.83%
Jadavpur University	Jadavpur University, 83, 4.72% Jadavpur University 83 publications, 4.72%
Chonbuk National University	Chonbuk National University, 46, 2.62% Chonbuk National University 46 publications, 2.62%
Indian Institute of Technology Kanpur	Indian Institute of Technology Kanpur, 44, 2.5% Indian Institute of Technology Kanpur 44 publications, 2.5%
Indian Institute of Technology Delhi	Indian Institute of Technology Delhi, 38, 2.16% Indian Institute of Technology Delhi 38 publications, 2.16%
University of Burdwan	University of Burdwan, 33, 1.88% University of Burdwan 33 publications, 1.88%
Birla Institute of Technology, Mesra	Birla Institute of Technology, Mesra, 31, 1.76% Birla Institute of Technology, Mesra 31 publications, 1.76%
Indian Institute of Technology (Indian School of Mines) Dhanbad	Indian Institute of Technology (Indian School of Mines) Dhanbad, 24, 1.37% Indian Institute of Technology (Indian School of Mines) Dhanbad 24 publications, 1.37%
Indian Association for the Cultivation of Science	Indian Association for the Cultivation of Science, 24, 1.37% Indian Association for the Cultivation of Science 24 publications, 1.37%
Indian Institute of Science	Indian Institute of Science, 22, 1.25% Indian Institute of Science 22 publications, 1.25%
Indian Institute of Technology Guwahati	Indian Institute of Technology Guwahati, 22, 1.25% Indian Institute of Technology Guwahati 22 publications, 1.25%
University of Erlangen–Nuremberg	University of Erlangen–Nuremberg, 22, 1.25% University of Erlangen–Nuremberg 22 publications, 1.25%
Aligarh Muslim University	Aligarh Muslim University, 21, 1.2% Aligarh Muslim University 21 publications, 1.2%
Indian Institute of Engineering Science and Technology, Shibpur	Indian Institute of Engineering Science and Technology, Shibpur, 20, 1.14% Indian Institute of Engineering Science and Technology, Shibpur 20 publications, 1.14%
National Metallurgical Laboratory	National Metallurgical Laboratory, 20, 1.14% National Metallurgical Laboratory 20 publications, 1.14%
Korea Institute of Science and Technology	Korea Institute of Science and Technology, 17, 0.97% Korea Institute of Science and Technology 17 publications, 0.97%
National Institute of Technology Silchar	National Institute of Technology Silchar, 16, 0.91% National Institute of Technology Silchar 16 publications, 0.91%
Indian Institute of Technology Bombay	Indian Institute of Technology Bombay, 14, 0.8% Indian Institute of Technology Bombay 14 publications, 0.8%
Kalinga Institute of Industrial Technology	Kalinga Institute of Industrial Technology, 14, 0.8% Kalinga Institute of Industrial Technology 14 publications, 0.8%
Sikkim University	Sikkim University, 12, 0.68% Sikkim University 12 publications, 0.68%
Hanyang University	Hanyang University, 12, 0.68% Hanyang University 12 publications, 0.68%
SRM Institute of Science and Technology	SRM Institute of Science and Technology, 11, 0.63% SRM Institute of Science and Technology 11 publications, 0.63%
King Abdulaziz University	King Abdulaziz University, 9, 0.51% King Abdulaziz University 9 publications, 0.51%
University of Calcutta	University of Calcutta, 9, 0.51% University of Calcutta 9 publications, 0.51%
Motilal Nehru National Institute of Technology Allahabad	Motilal Nehru National Institute of Technology Allahabad, 9, 0.51% Motilal Nehru National Institute of Technology Allahabad 9 publications, 0.51%
National Institute of Science Education and Research	National Institute of Science Education and Research, 9, 0.51% National Institute of Science Education and Research 9 publications, 0.51%
Bhabha Atomic Research Centre	Bhabha Atomic Research Centre, 9, 0.51% Bhabha Atomic Research Centre 9 publications, 0.51%
King Fahd University of Petroleum and Minerals	King Fahd University of Petroleum and Minerals, 8, 0.46% King Fahd University of Petroleum and Minerals 8 publications, 0.46%
Central Scientific Instruments Organisation	Central Scientific Instruments Organisation, 8, 0.46% Central Scientific Instruments Organisation 8 publications, 0.46%
	50 100 150 200 250 300