A research about a method for restoration of traditional lime mortars and plasters: A staging system approach

Turkey is quite rich with historical buildings. Depending on various factors like time, increasing air pollution due to technological improvements of the present era together with insufficiency of inspection leads to the formation of damages on these buildings which are part of our historical heritage. Conservation of such buildings which are as important as historical documents should be the first and foremost target of any project. Where maintenance is insufficient, conservation and restoration attempts should replace it. What is necessary in restoration is the use of material which resembles the original material to the closest degree or, producing appropriate material which is compatible with the properties of the original material. The first dimension of the current problem is the insufficiency of resources while the second dimension stems from the lack of proper evaluation of the material to be used in conservation and restoration. This study defines the importance of mortars and plasters along with their history and the reasons of deterioration. In addition, it sets up the information flow of mortar and plaster within a systematic decision making process. The necessary experimental methods for the production of new repair mortar or plaster that can be used in determining the character analysis of original mortar and deterioration morphology are also analyzed. Thus, a method that can be used in the conservation and restoration studies is determined with this paper.     

Essais d'aerateurs: Enseignements tires de 500 essais en eau claire effectues dans 200 stations d'epuration differentes—II ResultatsTests on aerators: Conclusions drawn from 500 clean water tests conducted in 200 different sewage treatment plants—II Data interpretation

The large number of aerator tests conducted in the field by the CEMAGREF teams has allowed developing a critical review of tests results by means of statistical analysis. Measurement quality is estimated from the variation of the transfer coefficient values from one sampling point to another. Individual transfer coefficient values $\text{(}\text{K}{}_{\mathrm{L}}\text{a)i}$ are compared with the average value of the test $\text{(}\text{K}{}_{\mathrm{L}}\text{a). (K}{}_{\mathrm{L}}\text{a)i/}\text{K}{}_{\mathrm{L}}\text{a}$ ratios correlating with one year's data are gathered in histogramms (Fig. 1).A χ² test is used for evaluating the fit of a Normal distribution on each histogram (Tables 1 and 2 results for two kinds of surface aerators). When the Normality is not rejected, the variances between distributions are compared by means of a Fisher test.$\text{(K}{}_{\mathrm{L}}\text{a)i/}\text{K}{}_{\mathrm{L}}\text{a}$ variations in a same run are independent of transfer coefficient when the K_La ranges 1–10 h^?1 and applied specific power ranges 15–70 W m^?3. Those variations allow evaluating the technique of measuring, the reliability of oxygen probes and the operator's experience (Table 3).In a well mixed tank and when the recommended procedure is correctly implemented the relative error in measuring the specific oxygen input (kg O₂ kWh^?1) is 5%. In less favorable cases it reaches 10%.Tables 4 and 5 show the reproductibility of repetitive run results in the same plant and of tests performed with the same aerator in different plants.The histograms of the performances of the main types of mechanical surface aerators (high speed vertical shaft turbine, slow speed vertical shaft turbine, horizontal shaft aerator) are presented (Figs 2, 4, 5). Relations between oxygenation capacity and specific power consumption are plotted in Figs 3 and 6. As to other aeration systems, fewer data are available. Table 6 summarizes the usual range of performances.In 1974, after a series of measurements performed on 72 different plants, CEMAGREF stated that the oxygenation capacities claimed by manufacturers were, on the average, 40% higher than actual results. Now, the performances predicted by manufacturers in France are generally very close to the measured values. A difference higher than 10% between predicted values and measured ones now occurs as an exception.     

Radon concentration in houses over a closed Hungarian uranium mine

High radon concentration (average 410 kBq m-3) has been measured in a tunnel of a uranium mine, located 15-55 m below the village of Kovágószolos, Hungary. The mine was closed in 1997; the artificial ventilation of the tunnel was then terminated and recultivation works begun. In this paper, a study has been made as to whether the tunnel has an influence on the radon concentration of surface dwellings over the mining tunnel. At different distances from the surface projection of the mining tunnel, radon concentration, the gamma dose, radon exhalation and radon concentration of soil gas were measured. The average radon concentration in the dwellings was 483 Bq m-3. Significantly higher radon concentrations (average 667 Bq m-3) were measured in houses within +/-150 m from the surface projection of the mining tunnel +50 m, compared with the houses further than the 300-m belt (average 291 Bq m-3). The average radon concentration of the soil gas was 88.8 kBq m-3, the average radon exhalation was 71.4 Bq m-2 s-1 and higher values were measured over the passage as well. Frequent fissures crossing the passage and running up to the surface and the high radon concentration generated in the passage (average 410 kBq m-3) may influence the radon concentration of the houses over the mining tunnel.     

Reviews

DROUGHT AND FAMINE IN ETHIOPIA Editor: Abdul Mejid Hussein. African Environment Special Report No. 2, The International African Institute, London, 1976,121 pp. £1.50.

HEDGING (A Practical conservation handbook) Alan Brooks, The British Trust for Conservation Volunteers, The Zoological Gardens, Regents Park, London, 1975. 117 pp. £2.10 inc. postage.

THREE JOURNALS Habitat: Published by : The Council for Nature, The Zoological Gardens, Regents Park, NW1 4RY. At £2.50, or £5.00 per annum.

Recreation News: Published by: The Countryside Commission , John Dower House, Crescent Place, Cheltenham, Glos., GL50 3RA.

The International Journal of Environmental Studies: Published by : Gordon Breach Science Publishers Ltd., 42 William IV Street. London, W.C.2. £17.50 for individuals, £35.00 for Libraries. Habitat

A HISTORY OF LANCASHIRE J.J. Bagley, Phillimore & Co. Ltd., London & Chichester 1976. 128 pp. £4.95.     

Analysis and jointing of polygonal road slabs

Conclusions 1. For anlaysis of circular (polygona) slabs which can be included in the category of absolutely rigid slabs, a practical approximate method of analysis has been developed and experimentally verified which permits determining the bending moments under centrally and eccentrically applied loads acting over a small circular area, as well as at any other points in the slab beyond the limits of the loaded area.2. Monolithic bonding of hexagonal road slabs up to 3–4 m² in area designed for the N-30 load results in increased design bending moments and, consequently, in thicker pavements. For these slabs it is expedient to use nonrigid joints, which do not transmit bending or torsional moments; however, these slabs must be placed on stabilized beds and their joints must be filled with waterproofing mastic.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 19–22, September–October, 1974.     

Toxicity, accumulation and elimination studies of α-hexachlorocyclohexane (α-HCH) with freshwater organisms of different trophic levels

A short- and long-term toxicity study with α-hexachlorocyclohexane (α-HCH) was carried out with freshwater organisms of different trophic levels (algae, crustaceae and fishes). In this study mortality, immobilization, growth, reproduction, histopathologic changes and enzyme activities were chosen as criteria.Furthermore accumulation and elimination processes were investigated in separate organisms as well as the uptake of α-HCH by one organism and through a food-chain.Finally a tentative method for deriving an “ecological limit” for χ-HCH in surface water is described.     

Paleonutritional analysis of the pre-Hispanic population from Fuerteventura (Canary Islands)

In this study, from histological and chemical perspectives, we analyse the human remains belonging to the pre-Hispanic inhabitants from Fuerteventura (one of the Canary Islands) and compare the results with those obtained on a sample of pre-Hispanic inhabitants from Gran Canaria (Canary Islands). We observe that trabecular bone mass was normal in the samples from Fuerteventura except for an elderly woman; this result is in sharp contrast with the decreased bone mass observed in the population from Gran Canaria. The pre-Hispanic population from Fuerteventura showed lower bone strontium, Sr/Ca ratio, and bone barium, but slightly higher bone copper, than that from Gran Canaria. All these data indicate a greater consumption of marine products by the population of Fuerteventura. The high prevalence of osteoporosis observed in the population from Gran Canaria may be interpreted as a consequence of protein-calorie malnutrition, a condition which seemed to be not so prevalent in the population of Fuerteventura.     

Structural analysis of assemblages of thin-walled members

A matrix method for the analysis of structural systems composed of thin-walled members is presented. The matrix displacement analysis includes the effects of thin-walled non-uniform torsion theory, cross-section asymmetry, eccentric restraint as well as joint types peculiar to thin-walled members. The method is used for a prediction of the elastic behaviour of a set of representative test frames. The test frames were pitched-roof portals constructed from channel sections bent about their major-axis and supported by eccentric restraints simulating purlins and girts.     

Sensory evaluation of drinking water by consumer panels

The human senses play an important role in assessing the quality of food and of the environment. Particularly the chemical senses of taste and smell determine the pleasantness of foods and drinks and may provide a warning mechanism for the presence of more or less toxic contaminants. Even after the recent rapid development of powerful analytical techniques the human nose can easily detect trace amounts of chemicals at levels manytimes lower than the analytical detection limits.Although taste and odour assessment of drinking water has been practized inmany waterworks laboratories by small panels, relatively unreliable results were obtained and such sensory data played up till now only a minor role in the management of the water treatment plant. More sophisticated and reliable methods for sensory water quality evaluation are discussed. Special attention is given to the characteristics of the human senses of taste and smell, to which the methodology of sensory assessment should be better adapted. High numbers of observations on a sample are generally needed, for which purpose the use of large panels has to be realized. In this respect the help of large consumer panels is an alternative for the presently often used small laboratory groups. As an example the preliminary results of a large ongoing experiment of sensory water quality assessment by 2 consumer panels of 100 persons each in the Rotterdam area are discussed. Drinking water quality is judged at the consumer homes every week. The experiment started September 1979 and will be continued for one year.