نتایج جستجو برای: haze

تعداد نتایج: 3091  

2017
Shenglan Zeng Yu Zhang

Meteorological conditions significantly influence air pollution. The Chengdu plain, with few external pollution sources and homogeneous meteorological conditions, is a natural lab to study the effects of meteorological elements on the diffusion and dissipation of pollutants. Large-scale and long-duration haze events occurred all over China during the Spring Festival in 2014. This study tries to...

2016
Jing Yuan Lingbing Bu Xingyou Huang Haiyang Gao Robert W. Talbot

To investigate the particulate characteristics of a haze episode, data from two ceilometers with wavelengths of 532 nm and 910 nm, respectively, were studied intensively. By combining the data from the ceilometers with data from a sounding balloon, an automatic meteorological station, and a Grimm 180 PM instrument, analyses of the haze process of a short haze event were performed. The results s...

2009
Boon Ning CHEW Chew Wai CHANG Santo Valentin SALINAS Soo Chin LIEW

ABSTRACT: Smoke haze related to biomass burning is a recurring environmental problem in Southeast Asia which has affected air quality not only in the source regions, but also in the surrounding areas. Air quality monitoring stations and meteorological stations in the region provide valuable information on the concentrations of criteria pollutants such as sulphur dioxide, nitrogen oxide, carbon ...

2015
Laura De Pretto Stephen Acreman Matthew J. Ashfold Suresh K. Mohankumar Ahimsa Campos-Arceiz Krishna Prasad Vadrevu

Transboundary haze episodes caused by seasonal forest fires have become a recurrent phenomenon in Southeast Asia, with serious environmental, economic, and public health implications. Here we present a cross-sectional survey conducted among people in Kuala Lumpur and surrounds to assess the links between knowledge, attitudes, and practices in relation to the transboundary haze episodes. Of 305 ...

Journal: :Ophthalmology 2004
Amin Ashrafzadeh Roger F Steinert

OBJECTIVE To evaluate the efficacy and safety of phototherapeutic keratectomy (PTK) for treatment of striae in LASIK flaps. DESIGN Retrospective consecutive series. PARTICIPANTS Forty-seven eyes of 44 patients with flap striae after LASIK with reduced best-corrected visual acuity (VA) or visual symptoms with at least 3 months' follow-up (consecutive cases from January 2001 to May 2004). I...

Journal: :Survey of ophthalmology 2009
Miguel A Teus Laura de Benito-Llopis Jorge L Alió

Mitomycin C has played a deciding role in the current revival of excimer laser surface ablation techniques. We review the literature regarding mechanism of action of mitomycin C, histological effects on the cornea, and indications, dose, exposure time, and toxicity of mitomycin C in corneal refractive surgery. Mitomycin C is an alkylating agent with cytotoxic and antiproliferative effects that ...

Journal: :Journal of geophysical research 1992
D V Michelangeli M Allen Y L Yung R L Shia D Crisp J Eluszkiewicz

The presence of a stratospheric haze layer may produce increases in both the actinic flux and the irradiance below this layer. Such haze layers result from the injection of aerosol-forming material into the stratosphere by volcanic eruptions. Simple heuristic arguments show that the increase in flux below the haze layer, relative to a clear sky case, is a consequence of "photon trapping." We...

2016
M. Ramesh Kanthan

The goal of Haze Removal algorithms is to recover and enhanced the scene from foggy image. Many applications need accurate Haze Removal algorithms. The de-fog feature works through a complex algorithm which based on the fog destiny of the scene, then analyses the atmospheric light and sharpness adjustments to produce image enhancement. In contrast with existing technology the proposed method fo...

Journal: :CoRR 2016
Felipe Codevilla Joel D. O. Gaya Amanda C. Duarte Silvia Silva da Costa Botelho

This paper describes a method to restore degraded images captured in general participative media — fog, turbid water, sand storm, etc. To obtain generality, we, first, propose a novel interpretation of the participative media image formation by considering the color variation of the media. Second, we introduce that joining different image priors is an effective alternative for image restoration...

2001
Yoav Y. Schechner Srinivasa G. Narasimhan Shree K. Nayar

We present an approach to easily remove the effects of haze from images. It is based on the fact that usually airlight scattered by atmospheric particles is partially polarized. Polarization filtering alone cannot remove the haze effects, except in restricted situations. Our method, however, works under a wide range of atmospheric and viewing conditions. We analyze the image formation process, ...

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