1 DR. AVRAHAM KUDISH Monitoring Solar Radiation. A method for the characterization and comparison of different sites with regard to their suitability for the utilization of solar energy was developed on the basis of statistical analysis of the solar radiation intensities at those sites. Each monthly data set of the daily global, horizontal beam, and diffuse radiation intensities was analyzed for the following parameters: monthly average of daily radiation intensity, coefficient of variation, skewness and kurtosis. The values of the skewness and kurtosis were applied to describe the distribution curves for each set of radiation intensity data. Photoclimatherapy at the Dead Sea. The Dead Sea basin, the lowest terrestrial point on earth, is recognized worldwide as a natural treatment center for patients with various cutaneous and rheumatic diseases. The major skin disease treated at the Dead Sea is psoriasis with more than 85% of patients showing excellent improvement to complete disappearance of the symptoms after four weeks of treatment. These findings are thought to be associated with the unique spectrum of ultraviolet radiation in the Dead Sea area. To investigate this supposition, UV measurements were conducted continuously at Neve Zohar, which is situated in the Dead Sea basin (-375 m), and, for purposes of comparison, in Beer-Sheva (+315 m). The measurements were performed with a Microtops II Ozone Monitor and Sunphotometer (Solar Light Co., Inc.) system, which was originally designed to monitor the thickness of the ozone layer. It was found that the ultraviolet radiation at the Dead Sea is attenuated relative to that in Beer-Sheva due to the increased optical path length and the consequent enhanced scattering (i.e., natural attenuation). More importantly, at the Dead Sea, UVB radiation is attenuated to a greater extent than UVA radiation, with the shorter erythema-causing UVB wavelength (about 305.5 nm) being significantly decreased vis-a-vis the longer therapeutic UVB wavelength (about 312 nm). It was also found that the relative radiation intensities, i.e., erythema-to-therapeutic wavelength ranges within the UVB spectrum are a function of the time of day, peaking at solar noon and decreasing towards the early and late hours of the day. Diurnal measurements of the relative radiation intensities can thus be used to design a photoclimatherapy protocol that minimizes exposure to the erythema rays while optimizing the dose of beneficial wavelengths. Aerosol Composition and Particle Size Distribution of the Air at the Dead Sea. As part of an ongoing study on the bioclimatological parameters in the Dead Sea Basin, the aerosol composition and particle size distribution of the atmosphere in this region is being determined. During the latter part of 2000, preliminary aerosol measurements were initiated at the Dead Sea by means of a TE-6000 PM10 MFC high-volume air sampler (Tisch Environmental, Inc.) for particulate matter 10 microns or less together with Andersen Series 230 high-volume cascade (4) impactors. Solar Desalination. A simulation model describing a solar collector containing a selectively coated, polymeric, double-walled absorber plate with parallel fluid flow channels was developed and validated utilizing experimental data from a solar collector module. The simulation model contained a refined radiative energy balance, which took 2 into consideration the fact that the glazing may not be totally opaque to long wavelength radiation. The model was solved by applying numerical integration to the non-linear differential equations describing the system. The validated simulation model was then utilized to perform sensitivity studies on the design parameters of the system. Relevant Publication Kudish, AI, Evseev, EG, Walter, G and Leukefeld, T: A simulation study of a solar collector with a selectively coated polymeric double-walled absorber plate. Energy Conversion and Management (in press). Ianetz, A, Lyubansky, V, Evseev, EG and Kudish, AI: Correlations for determining the daily diffuse radiation as a function of daily beam radiation on a horizontal surface in the semi-arid region of Israel. Theoretical and Applied Climatology (in press). Kudish, AI and Evseev, EG: Statistical relationships between solar UVB and UVA radiation and radiation measurements at two sites in Israel. Int. J. Climatology 20:759770; 2000. Ianetz, A, Lyubansky, V, Setter, I, Evseev, E.G and Kudish, A.I: A method for characterization and inter-comparison of sites with regard to solar energy utilization by statistical analysis of their solar radiation data as performed for three sites in the Negev region of Israel. Solar Energy 69:283-293; 2000. Kudish, AI, Mink, G, Evseev, EG and Horváth, L: Technical and economic features of advanced air-blown solar desalination systems. International Congress Energy and the Environment 2000; 2000 Oct.; Opatija. (p. 89-97). (Proceedings, vol. I). Ianetz, A, Lyubansky, V, Setter, I, Evseev, EG and Kudish, AI: An inter-comparison of the radiation intensities measured at three sites in the southern region of Israel by regression analysis. World Renewable Energy Congress-VI, Renewables: The Energy for the 21st Century; 2000 July; Brighton. (p. 2477-2480). (Proceedings, vol. IV). Mink, G, Horváth, L, Evseev, EG and Kudish, AI: Performance and analysis of a multipleeffect solar still utilizing an internal multi-tubular heat exchanger for thermal energy recycle. International Solar Energy Society Conference, Solar World Congress; 1999 July; Jerusalem. (p. 226-235). (Proceedings, vol. III). Kudish, AI, Evseev, EG, Horváth, L and Mink, G: Performance and analysis of a multipleeffect solar still utilizing solar and/or waste thermal energy. International Solar Energy Society Conference, Solar World Congress; 1999 July; Jerusalem. (p. 216225). (Proceedings, vol. III). Lyubansky, V, Ianetz, A, Seter, I, Kudish, AI and Evseev, EG: Characterization and intercomparison of the global and beam radiation measured at three sites in the southern region of Israel by statistical analysis. International Solar Energy Society Conference, Solar World Congress; 1999 July; Jerusalem. (p. 419-426). (Proceedings, vol. I). Kudish, AI, Evseev, EG, Rommel, M, Köhl, M, Walter, G and Leukefeld, T: Research and development of solar collectors fabricated from polymeric material. International Solar Energy Society Conference, Solar World Congress; 1999 July; Jerusalem. (p. 40-49). (Proceedings, vol. III).