AIM:We sought to compare the antioxidant effects of resveratrol (R) and melatonin (M) after 70% partial hepatectomy (PH) as evidenced by ultrastructural alterations and effects on hepatocyte proliferation and apoptosis. METHODS:Twenty-six male Wistar albino rats were randomized into four groups: group A (n = 8) resveratrol (R); group B (n = 8) melatonin (M); group C (n = 5) control PH; group D (n = 5) sham operated animals. The rats that received either R or M were sacrificed a week after PH. The malondialdehyde, glutathione, glutathione S-transferase, and nitric oxide levels were estimated in liver homogenates. The morphological changes were investigated using light and electron microscopy (EM). Cell proliferation was detected by immunohistochemical staining with monoclonal antibodies to Ki-67. Apoptosis was detected by the transferase-mediated dUTP nick end-labeling method. RESULTS:PH induced hepatic LP, decreased GSH and NO, and inhibited GST activity (P < .05). R and M completely prevented PH-induced lipid peroxidation, decreased hepatic GSH and NO levels (P < .05). The inhibition of GST activity was prevented by R (P < .05), but not with M (P > .05). In the PH group EM showed severe morphological changes: mitochondrial degeneration, vacuoles, lipid droplets, and myelin-like figures. In both the R and M groups, morphological alterations repaired protective effects more prominently in the R group. Ki-67 indices (KI) were increased in the PH group and decreased in both R and M groups (P < .001). In the M group, KI was the lowest, but the difference compared with R was not significant (P > .05). Apoptosis was slightly increased in PH, but in either the R or M groups, apoptosis was intensively increased (P < .001). Increased apoptosis was greatest in the M group and the difference compared with the R group was statistically significant (P < .05). CONCLUSION:R and M suppressed PH-induced oxidative damage, attenuated proliferation, and stimulated apoptosis. When we compared R and M, R showed more potent antioxidative effects and was morphologically more protective to hepatocytes. Antiproliferative effects of M were more potent. Because of their potent antioxidative effects, R and M can be effective for oxidative damage like ischemia-reperfusion injury; however, because of the adverse effects on proliferation and apoptosis more studies are needed in states in which regeneration is critical.

This study is based on thermal performance analysis and evaluation of the National Observatory guesthouse with the software SUNCODE-PC.The study is unique owing to its high-altitude site (2465 m) in a remote area, harsh climate (with almost no data available), and functional restrictions of astronomical facilities.The design is thermally evaluated through different modes of application of insulation, materials, types of glazing, window/wall ratios, Trombe walls, winter night insulation, summer ventilation and shading.

In this paper, we discuss the possibility of using the daily sunshine duration or the daily sunshine duration over day-length data instead of daily global solar radiation in order to develop a Typical Meteorological Year, TMY2, for localities with abundant data of daily sunshine duration. The analysis is done using the latest methodology proposed in the literature. The number of coinciding months is about 40% when daily sunshine duration or the daily sunshine duration over day-length data is used instead of daily global solar radiation as one of the parameters in obtaining TMY2. Such a relatively low figure is probably due to the unreliable solar radiation data recorded by Robitzch-type actinographs used in the present work.

The study aims to develop energy conscious dwellings in climatic conditions of Ankara. Since the computer program SUNCODE-PC is used for thermal performance analysis, an hourly climatic data set for an average year has been prepared. Two design proposals are developed and compared: one of them is designed with conventional features and the other is designed energy consciously. Improvement studies are conducted on the energy conscious design.

The main objective of the study is to analyze the design parameters of mass-housing for finding out their effect on heating energy demand and solar heating. The analyzed parameters for mass-housing are spacing between the buildings, the dimensions and materials of the buildings, the geometry and its orientations, the size of windows and its orientation. Within the framework of the study, it also aimed at supplying a guide to the city parameters and designers. The guide, containing samples of differant configurations of the settlement, may provide them alternatives so that they can make comparison within the samples and their designs. Each sample representing a change in a parameter gives the designer an idea how such parameters affect the heating energy demand. A mass-housing district at Ankara, capital of Turkey, is selected for the case study due to its large number of mass-housing applications and easy data collection.

In this report we discuss the present situation of solar water heating for domestic supplies in Turkey and give the results of a computer analysis for nine distinct regions. The analyses are carried out for four typical days of the four seasons and also on a monthly base. The results show that detailed initial work must be carried out before installing the system to determine the optimized collector area. Such analysis can provide efficient using of the Sun's energy as well as economical benefits in the initial investments and long term utilization.

A thermosyphon solar water heating system with an in-tank auxiliary electric heater has been simulated for different hot water load temperatures using the TRNSYS simulation program. The results of the simulation show that the annual efficiency and solar fraction are functions of the hot water load temperatures. The effect of load temperature on the solar fraction is found to be very large when the daily load volume (the volume of hot water delivered to load) to collector area ratio is large. The influence of storage tank volume to collector area ratio on the efficiency of the collector is observed only when this ratio is less than or equal to 40 1 m2 for all collector areas and load temperatures studied. Generally, the annual average storage tank temperature depends on the load temperature and had lower values for high load temperatures. The response of the system performance to the area of the collector is found to be very large when the system operates with a solar fraction below 70%.

Three built-in-storage-type solar water heaters of equal volume were tested under identical conditions for performance evaluation. One of these water heaters was rectangular and the other two were triangular. One of the triangular water heaters had a baffle plate and the other did not. The triangular water heater with baffle plate was found to be not superior to the rectangular one in efficiency during the heating period. However, it was more efficient during the cooling period. The triangular water heater without the baffle plate was found to be the most efficient one during both the heating and the cooling periods.

In this paper, five sunshine-based correlations, namely, Benson et al, Gopinathan, Ögelman et al, Zabara and our new quadratic correlation are evaluated in terms of predictive accuracy. The data for 67 stations, ranging in altitude between 3 and 2210 m and in latitude between 20.15 °S and 53.30 °N, have been used. The new solar constant 1367 W m −2 is used in the analysis. The overall results show that the correlations of Benson et al and Gopinathan fall in the second rank and that the difference in estimation errors for the other three is negligibly small. Use of the new quadratic correlation is proposed because of its relatively wider spectrum of values for a and b .

In this paper, a new correlation for the estimation of monthly average daily global solar radiation will be presented and compared with the correlations of Rietveld, Benson et al. , Ögelman et al. , and a recent formulation by Gopinathan. The overal results show that the quadratic form gives better performance in terms of global applicability. The new quadratic model should be preferred for the monthly average global solar radiation estimation when the data for bright sunshine hours are available.

Triangular built-in-storage solar water heaters of different volumes are studied. These is good agreement between the mathematical model and the experimental results. The collectors are observed to operate with high efficiency during the heating period and also during the 24-hour cycle.

Global irradiances incident on a horizontal surface are estimated from the bright sunshine hour measurements over Turkey. Global radiation and its components on daily and hourly bases are computed for the surfaces with any inclination and orientation. Some demonstration results are presented for the six climatologically different regions. Numerous hourly and daily computer output tables of global direct and diffuse radiations are obtained for 50 locations, which have been used to prepare a solar radiation handbook of Turkey.

Daily values of HH0, the ratio of total horizontal radiation to that outside the atmosphere has been correlated with sS, bright sunshine as a fraction of daylength for 3 yr measurements in Adana and Ankara, Turkey. Using a maximum-likelihood quadratic fit, we show that monthly averages 〈sS〉 and its standard deviation σsS can be used to estimate the monthly average 〈HH0〉 as 〈HH0〉 = 0.204 + 0.758〈sS〈 − 0.250[〈sS〈2 + σ2sS. Comparison of the estimations of the above equation with measurements from different regions of Turkey indicate that less than 5 per cent relative error is possible. A further correlation σ2sS with 〈sS〉 makes it possible to estimate 〈HH0〉 with just the knowledge of 〈sS〉.

Electroplated black nickel selective absorber is one of the most commercially used element of solar energy systems. Electrodeposition parameters such as time of deposition, pH, current density, electrolyte temperature should be optimized to produce the most efficient selective absorber. The topology of the substrate material is very effective on selectivity and it should also be optimized. In this study, by controlling the conditions of electrodeposition black nickel selective absorbers are produced and their reflectivities are measured. The effects of the electrodeposition parameters together with the topology of the substrate, on the selective properties are investigated.

Four types of collectors having the same geometry but different collector properties have been examined for the nine locations of Turkey having different climatic conditions. Optimum tilt angles for these collectors are calculated and found to be latitude plus 15/sup 0/ for winter, latitude minus 23/sup 0/ for summer and equal to the latitude for the yearly value, independent of the location. A different absorber surface geometry has been considered to increase the fin efficiency and the four collector types are then grouped as A and B types according to their overall loss factors. Collector types A and B, integrated with four different volumes of storage tanks are used to calculate the annual fraction of the house heating load supplied by solar, by using the ''average day'' method. By the aid of the economic assesments the payback period of solar house heating systems are found with reference to the economic state of Turkey.