PEREYRA R. G., SEBASTIANELLI P; AVILA E.E.

Homogeneous nucleation in supercooled liquid water. Determination of ice germ size and activation energy barrier in Molecular Dynamics simulations

MOLECULAR SIMULATION; Lugar: Londres; Año: 2022

ÁVILA, ELDO; MARTÍNEZ, LUCIA; PEREYRA, RODOLFO; LANG, TIMOTHY; DEIERLING, WIEBKE; WINGO, MATTHEW; MELO, GREGORY; MEDINA, BRUNO

Measurements of Size and Electrical Charges Carried by Precipitation Particles During RELAMPAGO Field Campaign

Earth and Space Science; Año: 2022 vol. 9

BAISSAC, DAIANA M.; NICORA, M. GABRIELA; BALI, LUCAS J.; BADI, GABRIELA A.; ÁVILA, ELDO E.

Volcanic alert system by lightning detection using the WWLLN - ash cloud monitor

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES; Año: 2021 vol. 108

NESBITT, STEPHEN W.; SALIO, PAOLA V.; ÁVILA, ELDO; BITZER, PHILLIP; CAREY, LAWRENCE; CHANDRASEKAR, V. ETC...

A storm safari in Subtropical South America: proyecto RELAMPAGO

BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY; Año: 2021 p. 1 - 64

TIMOTHY J. LANG, ELDO E. ÁVILA, RICHARD J. BLAKESLEE, JEFF BURCHFIELD, MATTHEW WINGO, PHILLIP M. BITZER, LAWRENCE D. CAREY, WIEBKE DEIERLING, STEVEN J. GOODMAN, BRUNO LISBOA MEDINA, GREGORY MELO, AND RODOLFO G. PEREYRA

The RELAMPAGO Lightning 1 Mapping Array: 2 Overview and initial comparison to the Geostationary Lightning Mapper

JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY; Lugar: Boston; Año: 2020

LUQUE, MELINA Y.; NOLLAS, FERNANDO; PEREYRA, RODOLFO G.; BÜRGESSER, RODRIGO E.; ÁVILA, ELDO E.

Charge Separation in Collisions Between Ice Crystals and a Spherical Simulated Graupel of Centimeter Size

Journal of Geophysical Research: Atmospheres; Año: 2020 vol. 125

LUQUE, M.Y.; BÜRGESSER, R.E.; ÁVILA, E.E.

Experimental measurements of charge separation under wet growth conditions

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 2018

PEDERNERA, DÉBORA ANALÍA; ÁVILA, ELDO E.

Frozen-Droplets Aggregation at Temperature Below -40°C

Journal of Geophysical Research: Atmospheres; Año: 2018

LÓPEZ, MARÍA LAURA; BORGNINO, LAURA; ÁVILA, ELDO E.

The role of natural mineral particles collected at one site in Patagonia as immersion freezing ice nuclei

ATMOSPHERIC RESEARCH; Año: 2018 vol. 204 p. 94 - 101

TIMOTHY J. LANG, STÉPHANE PÉDEBOY, WILL IAM RISON, RANDALL S. CERVENY, JOAN MONTANYÀ, SERGE CHAUZY, DONALD R. MACGORMAN, RONALD L. HOLL E, L; ELDO E. ÁVILA; YIJUN ZHANG, GREGORY CARBIN, EDWARD R. MANSELL , YURIY KULESHOV, THOMAS C. PETERS ON, MANOLA BRUNET, FATIMA DRIOUECH, AND DANIEL S. KRAHENBUH

WMO WORLD RECORD LIGHTNING EXTREMES

BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY; Lugar: Boston; Año: 2017

A. SANTOS, O. PINTO, S. SANNTOS, F. LOPES LIMA, E. BARREIROS SOUZA, B. MORAIS,; AVILA E. E.; PEDERNERA D.A.

Climatic Projections of Lightning in Southeastern Brazil using CMIP5 models in RCP?s scenarios 4.5 and 8.5

American Journal of Climate Change; Año: 2017

LOPEZ M.L.; AVILA E. E.

Influence of the ambient humidity on the concentration of natural deposition-mode ice-nucleating particles

ATMOSPHERIC CHEMISTRY AND PHYSICS; Lugar: Gottingen; Año: 2016 vol. 16 p. 927 - 932

BÜRGESSER R.; AVILA E. E.; CASTELLANO N.

Laboratory measurements of sedimentation velocity of columnar ice crystals

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Lugar: LOndres; Año: 2016

LUQUE M.; BÜRGESSER R.; AVILA E. E.

Thunderstorm graupel charging in the absence of supercooled water droplets

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Lugar: LOndres; Año: 2016

AVILA E. E.; BÜRGESSER R.; CASTELLANO N.; NICORA M.G.

Diurnal patterns in lightning activity over South America.

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2015

LOPEZ M.L.; CEPPI S.; M. L. ASAR; BÜRGESSER R.; AVILA E. E.

Rainwater analysis by Synchrotron Radiation-Total reflection X-ray Fluorescence

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY; Lugar: Amsterdam; Año: 2015

CASTELLANO N.; AVILA E. E.; BÜRGESSER R.; C. P. R. SAUNDERS

The growth of ice particles in a mixed phase environment based on laboratory observations

ATMOSPHERIC RESEARCH; Lugar: Amsterdam; Año: 2014

GARREAUD R.; M. G. NICORAL; BÜRGESSER R.; AVILA E. E.

Lightning in Western Patagonia.

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2014

NICORA M.G.; QUEL E.J.; BÜRGESSER R.; AVILA E. E.; ROSALES A.; SALVADOR J.; DELIA R.

LA ACTIVIDAD ELÉCTRICA ATMOSFÉRICA EN ARGENTINA. ESTIMACION DE LA TASA DE MORTALIDAD ANUAL POR ACCIÓN DE CAIDAS DE RAYOS

Anales AFA; Lugar: Tandil; Año: 2014 vol. 25 p. 151 - 156

A. COLLIER; BÜRGESSER R.; AVILA E. E.

Suitable regions for assessing long term trends in lightning activity

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; Lugar: Amsterdam; Año: 2013 vol. 92 p. 100 - 104

R. E. BÜRGESSER; NICORA M.G.; E. E. AVILA

Spatial and time distribution of the flash rate over tropical Africa

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; Lugar: Amsterdam; Año: 2013 p. 41 - 48

LOPEZ M.L.; AVILA E. E.

Measurements of natural deposition ice nuclei in Cordoba, Argentina

ATMOSPHERIC CHEMISTRY AND PHYSICS; Lugar: Gottingen; Año: 2013 p. 3111 - 3119

NICORA M.G.; BÜRGESSER R.; ROSALES A.; QUEL E.J.; AVILA E. E.

ACTIVIDAD ELECTRICA ASOCIADA A LA ERUPCION DEL COMPLEJO VOLCÁNICO CORDÓN CAULLE DURANTE 2011

METEOROLOGICA; Lugar: Buenos Aires; Año: 2013

AVILA E. E.; LIGHEZZOLO R. A.; CASTELLANO N.; PEREYRA R. G.; BÜRGESSER R.

Laboratory measurements of charge separation in low liquid water content conditions and low impact velocity

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2013 vol. 118 p. 1 - 8

LOPEZ M.L.; AVILA E. E.

Deformations of frozen droplets formed at -40ºC

GEOPHYSICAL RESEARCH LETTERS; Año: 2012 p. 1 - 5

BÜRGESSER R.; NICORA M.G.; AVILA E. E.

Characterization of the lightning activity of “Relámpago del Catatumbo”

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; Año: 2012 p. 241 - 247

M. L. ASAR; E. E. AVILA; R. A. TACCONE; S. I. LANE.

Estudio de laboratorio sobre la captura de acido acetico por gotas de nube

Anales AFA; Lugar: Buenos Aires; Año: 2012 p. 123 - 127

AVILA E. E.; BÜRGESSER R.; CASTELLANO N.; PEREYRA R.; C. SAUNDERS

Charge separation in low‐temperature ice cloud regions

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2011 p. 1 - 5

NE CASTELLANO; EE AVILA

Vapour density field of a population of cloud droplets

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; Año: 2011 vol. 73 p. 2423 - 2428

LIGHEZZOLO R. A.; PEREYRA R. G.; AVILA E. E.

Measurements of electric charge separated during the formation of rime by the accretion of supercooled droplets

ATMOSPHERIC CHEMISTRY AND PHYSICS; Año: 2010 vol. 10 p. 1661 - 1669

AVILA E. E.; R. E. BÜRGESSER; N. E. CASTELLANO; A. COLLIER; R. COMPAGNUCCI; A. HUGHES

Correlations between deep convection and lightning activity on a global scale

JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS; Año: 2010 vol. 72 p. 1114 - 1121

G.G. AGUIRRE VARELA; N. E. CASTELLANO; E. E. AVILA

Formation and sublimation of ice structures over cylindrical collectors

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER; Año: 2009 vol. 52 p. 5167 - 5172

E. E. AVILA; N. E. CASTELLANO; C. P. R. SAUNDERS; R. BÜRGESSER; G.G. AGUIRRE VARELA

Initial stages of the riming process on ice crystals

GEOPHYSICAL RESEARCH LETTERS; Año: 2009 vol. 36 p. 1 - 6

NESVIT E. CASTELLANO; ELDO E. AVILA; CLIVE P. R. SAUNDERS

Vapour density field of mixed-phase clouds

ATMOSPHERIC RESEARCH; Año: 2008 vol. 88 p. 56 - 65

MARCELO A. CARIGNANO; MARÍA M. JACOB; ELDO E. AVILA

On the uptake of ammonia by the water/vapor interface

JOURNAL OF PHYSICAL CHEMISTRY; Año: 2008 vol. 112 p. 3676 - 3679

PEREYRA RODOLFO; BÜRGESSER RODRIGO; ELDO E. AVILA

Charge separation in thunderstorm conditions

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2008 vol. 113 p. 1 - 12

R.L. DOWDEN; R.H. HOLZWORTH; C.J. RODGER; J. LICHTENBERGER; N.R. THOMSON; A.R. JACOBSON; E. LAY; J.B. BRUNDELL1; T.J. LYONS; S. O'KEEFE; Z. KAWASAKI; C. PRICE; V. PRIOR; P. ORTÉGA; J. WEINMAN; Y. MIKHAILOV; R. WOODMAN; X. QIE; G. BURNS; A. COLLIER; O. PINTO; R. DIAZ; C. ADAMO; E.R. WILLIAMS; S. KUMAR; G. B. RAGA; J.M. ROSADO; E.E. ÁVILA; M.A CLILVERD; T. ULICH; P. GORHAM; T.J. SHANAHAN; T. OSIPOWICZ; G. COOK; Y. ZHAO

World-Wide Lightning Location Using VLF Propagation in the Earth-Ionosphere Waveguide

IEEE ANTENNAS AND PROPAGATION MAGAZINE; Año: 2008 vol. 50 p. 40 - 60

AGUIRRE VARELA GUILLERMO; CASTELLANO NESVIT; ÁVILA ELDO

Effect of internal flux on the heat transfer coefficient in circular cylinders in cross flow

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER; Año: 2007 vol. 50 p. 4098 - 4104

CASTELLANO NESVIT; GANDI SILVANA; ÁVILA ELDO

A numerical study of the effects of cloud droplets on the diffusional growth of snow crystals

ATMOSPHERIC RESEARCH; Año: 2007 vol. 84 p. 353 - 361

M.A. MADRID; G.G. AGUIRRE VARELA; N.E. CASTELLANO; E.E. AVILA

ESTUDIO DE LA EVAPORACIÓN DE UNA POBLACIÓN DE GOTAS

ANALES AFA; Año: 2007 vol. 19 p. 260 - 263

BÜRGESSER RODRIGO; PEREYRA RODOLFO; ÁVILA ELDO

Charge separation in updraft of convective regions of thunderstorm

GEOPHYSICAL RESEARCH LETTERS; Año: 2006 vol. 33 p. 1 - 4

SAUNDERS CLIVE; BAX-NORMAN HOLLY; EMERSIC C.; ÁVILA ELDO; CASTELLANO NESVIT

Laboratory studies of the effect of cloud conditions on graupel/crystal charge transfer in thunderstorm electrification

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 2006 vol. 132 p. 2655 - 2676

ÁVILA ELDO; SAUNDERS CLIVE; CASTELLANO NESVIT; BAX-NORMAN HOLLY

Charge sign reversal in irregular ice-particle graupel collisions

GEOPHYSICAL RESEARCH LETTERS; Año: 2005 vol. 32 p. 1 - 4

AGUIRRE VARELA GUILLERMO; CASTELLANO NESVIT; ÁVILA ELDO

A possible influence on the density of ice accretions on their heat transfer coefficient

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 2005 p. 97 - 99

NESVIT E. CASTELLANO; ELDO E. AVILA; CLIVE P. R. SAUNDERS

Theoretical model of the Bergeron–Findeisen mechanism of ice crystal growth in clouds

ATMOSPHERIC ENVIRONMENT; Año: 2004 vol. 38 p. 6751 - 6761

CLIVE P. R. SAUNDERS; HOLLY BAX-NORMAN; ELDO E. AVILA; NESVIT E. CASTELLANO

A laboratory study of the influence of ice crystal growth conditions on subsequent charge transfer in thunderstorm electrification

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 2004 vol. 130 p. 1395 - 1406

E. E. AVILA; C. P. R. SAUNDERS; N. E. CASTELLANO; HOLLY BAX-NORMAN

Laboratory study of thunderstorm electrification

Proc. Intern. Coference on Lightning Physics and Effects; Año: 2004 p. 1 - 5

N. E. CASTELLANO; E. E. AVILA; C. P. R. SAUNDERS

A study of the effect of cloud droplets on the diffusional growth rate of ice particles

Proc. Intern. Conference on Clouds and Precipitation; Año: 2004 p. 1 - 4

G. G. AGUIRRE VARELA; N. E. CASTELLANO; R. G. PEREYRA; E. E. AVILA

The effect of surface lobes on heat transfer from an ice particle

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 2003 vol. 129 p. 3425 - 3438

E.E. AVILA; G.S. LONGO; R. E. BÜRGESSER

Mechanism for electric charge separation by ejection of charged particles from an ice particle growing by riming

ATMOSPHERIC RESEARCH; Año: 2003 vol. 69 p. 99 - 108

C. P. R. SAUNDERS; BAX-NORMAN HOLLY; E. E. AVILA

Laboratory studies of the effect of cloud conditions on charge transfer in thunderstorm electrification.

Proc. XII International Conference on Atmospheric Electricity; Año: 2003 p. 1 - 4

C. P. R. SAUNDERS; HOLLY BAX-NORMAN; R. MITZEVA; B. TSENOVA; E. E. AVILA; N. E. CASTELLANO

The effect of cloud conditions on charge transfer in thunderstorm

Proc. Intern. Conference on Lightning and Static Electricity; Año: 2003 p. 1 - 5

R.G. PEREYRA; E.E. AVILA

Charge transfer measurements during single ice crystal collisions with a target growing by riming

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2002 vol. 107 p. 1 - 9

C. SAUNDERS; S.L. PECK; G. G. AGUIRRE VARELA; E. AVILA; N. CASTELLANO

A laboratory study of the influence of the water vapour and mixing on the charge transfer process during collisions between ice crystals and graupel

ATMOSPHERIC RESEARCH; Año: 2001 vol. 58 p. 187 - 203

E. E. AVILA; R. G. PEREYRA; N. E. CASTELLANO; C. P. R. SAUNDERS

Ventilation coefficients for cylindrical collectors growing by riming as a function of the cloud droplet spectra

ATMOSPHERIC RESEARCH; Año: 2001 vol. 57 p. 139 - 150

E. E. AVILA; R. G. PEREYRA

Charge transfer during crystal-graupel collisions for two dierent cloud droplet size distributions

GEOPHYSICAL RESEARCH LETTERS; Año: 2000 vol. 27 p. 3837 - 3840

R. G. PEREYRA; E. E. AVILA; N. E. CASTELLANO; C. P. R. SAUNDERS

A laboratory study of graupel charging

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 2000 vol. 105 p. 20803 - 20812

G. G. AGUIRRE VARELA; N. E. CASTELLANO; E. E. AVILA; R. G. PEREYRA

Efecto de la rugosidad de la superficie sobre el coeficiente de transferencia de calor de cilindros circulares

ANALES AFA; Año: 2000 vol. 12 p. 256 - 259

E. E. AVILA; N. E. CASTELLANO; R. G. PEREYRA; C. P. R. SAUNDERS

Relationship between rime surface temperature and cloud droplet spectra

Proc. 13th Intern. Conference on Clouds and Precipitation; Año: 2000 p. 760 - 763

E. E. AVILA; N. E. CASTELLANO; C. P. R. SAUNDERS

Effects of cloud-droplet spectra on the average surface-temperature of ice accreted on fixed cylindrical collectors

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 1999 vol. 125 p. 1059 - 1074

E. E. AVILA; R. G. PEREYRA; G. G. AGUIRRE VARELA; G. CARANTI

The effect of the cloud-droplet spectrum on electrical-charge transfer during individual ice-ice collisions

QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY; Año: 1999 vol. 125 p. 1669 - 1679

N. E. CASTELLANO; E. E. AVILA; C. P. R. SAUNDERS

Dependence of the average surface temperature on cloud droplet spectra for rime ice accreted on fixed spherical collectors

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1999 vol. 104 p. 27399 - 27406

C. P. R. SAUNDERS; E. E. AVILA; S.L. PECK; N.E. CASTELLANO; G. G. AGUIRRE VARELA

A laboratory study of the effects of rime ice accretion and heating on charge transfer during ice crystalrgraupel collisions

ATMOSPHERIC RESEARCH; Año: 1999 vol. 51 p. 99 - 117

R. G. PEREYRA; E. E. AVILA; G. CARANTI; G. G. AGUIRRE VARELA

The effect of the cloud droplet spectrum on electrical charge transfer during individual ice-ice collisions

Proc. 11 Intern. Conference Atmospheric Electricity; Año: 1999 p. 292 - 295

C. P. R. SAUNDERS; S.L. PECK; E. E. AVILA; N. E. CASTELLANO

Vapor and heat supply to riming graupel: effect on charging

Proc. XI Intern. Conference on Atmospheric Electricity; Año: 1999 p. 268 - 271

E. E. AVILA; G. CARANTI; N. E. CASTELLANO; C. P. R. SAUNDERS

Laboratory studies of the influence of cloud droplet size on charge transfer during crystal-graupel collisions

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1998 vol. 103 p. 8985 - 8996

R. G. PEREYRA; G. G. AGUIRRE VARELA; E. E. AVILA; G. CARANTI

Medición de la carga eléctrica transferida a un sustrato de hielo en acreción, debido a múltiples colisiones con cristales de hielo

ANALES AFA; Año: 1997 vol. 9 p. 360 - 364

G. G. AGUIRRE VARELA; R. G. PEREYRA; E. E. AVILA; G. CARANTI

Transferencia de carga eléctrica en colisiones individuales entre esferas de hielo y un sustrato de hielo en acreción

ANALES AFA; Año: 1997 vol. 9 p. 355 - 359

G. G. AGUIRRE VARELA; R. G. PEREYRA; E. E. AVILA; G. CARANTI

Medición del tiempo de contacto cuando colisionan dos partículas

ANALES AFA; Año: 1997 vol. 9 p. 365 - 368

E. E. AVILA; G. G. AGUIRRE VARELA; G. CARANTI

Charging in ice-ice collisions as a function of the ambient temperature and the larger particle average temperature

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1996 vol. 101 p. 29609 - 29614

E. E. AVILA; G. G. AGUIRRE VARELA; G. CARANTI

Reply to comments on A laboratory study of static charging by fracture in ice growing by riming

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1996 vol. 101 p. 9537 - 9538

R. G. PEREYRA; E. E. AVILA; G. CARANTI

Laboratory study of cloud electrification

Proc. 10th Intern. Conference Atmospheric Electricity; Año: 1996 p. 52 - 55

E. E. AVILA; G. G. AGUIRRE VARELA; G. CARANTI

Temperature Dependence of Static Charging in Ice Growing By Riming

JOURNAL OF THE ATMOSPHERIC SCIENCES; Año: 1995 vol. 52 p. 4515 - 4522

M. SCAVUZZO; E. E. AVILA; G. CARANTI

Cloud electrification by fracture in ice-ice collisions: a 3D model

ATMOSPHERIC RESEARCH; Año: 1995 vol. 37 p. 325 - 342

E. E. AVILA; G. CARANTI

A Laboratory Study of Static Charging by Fracture in Ice Growing By Riming

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1994 vol. 99 p. 10611 - 10620

M. SCAVUZZO; E. E. AVILA; G. CARANTI

Estudio numerico de la electrificacion de nubes

METODOS NUMERICOS PARA CALCULO Y DESENO EN INGENIERIA; Año: 1994 vol. 10 p. 173 - 185

E. E. AVILA; G. CARANTI

A laboratory study of static charging by fracture in ice growing by riming

Proc 9th Internac. Conference on Atmospheric Electricity; Año: 1992 p. 100 - 103

M. SCAVUZZO; E. E. AVILA; G. CARANTI

A cloud electrification model using laboratory data

Proc 9th Internac. Conference on Atmospheric Electricity; Año: 1992 p. 404 - 407

E. E. AVILA; M. SCAVUZZO; G. CARANTI

Estudio sobre la electrificacion de cumulunimbus

Proc. V Congreso Iberoamricano de Meteorologia; Año: 1992 p. 1 - 5

G. CARANTI; E. E. AVILA; M. RE

Charge Transfer During Individual Collisions in Ice Growing

JOURNAL OF GEOPHYSICAL RESEARCH; Año: 1991 vol. 96 p. 15365 - 15375

E. E. AVILA; G. CARANTI

Charge transfer during individual collisions in ice growing by riming

NASA Conference Publication; Año: 1991 p. 1 - 15

G. CARANTI; M. RE; E. E. AVILA

Sistema de adquisición de datos para ZX-Spectrum

Revista Telegrafica Electronica; Año: 1991 p. 97 - 99

E. E. AVILA; G. CARANTI; M. LAMFRI

Charge reversal in individual ice-ice collisions

Proc. 8th Internac. Conference on Atmospheric Electricity; Año: 1988 p. 245 - 250