From Concentration to De-concentration — Migration Patterns in the Post-socialist City

The paper analyses the changing patterns of migration in the transition process from a “Socialist” into a “Capitalist” city against the background of “Modernization Theory”. Based on the example of Erfurt, a former district capital and now capital of the new federal state of Thuringia, an overview is given of basic population development trends before and after the unification of the two Germanys. A more detailed analysis of different urban areas (historic centre, city extensions of the industrial period, Socialist housing areas, new suburban housing areas) reveals a general turn-around of migration streams: Before 1990 the urban population showed a steady increase, while after reunification a dramatic loss could be observed. This decrease is caused both by emigration to areas in former West Germany, as well as by the beginning suburbanisation process. The latter is also fostered by the growing number of West – East migrants across the former internal German border. The findings are summarised in a model of the post-Socialist urban area.     

Performance of “ductless” personalized ventilation in conjunction with displacement ventilation: Impact of disturbances due to walking person(s)

The performance of the novel “ductless” personalized ventilation in conjunction with displacement ventilation (DV) was compared with the performance of DV alone under realistic conditions involving disturbances due to walking of one or two persons. An office room with two workstations was arranged in a full-scale test room. Two thermal manikins were used as sedentary occupants at the workstations. Two pollution sources, namely exhaled air by one of the manikins and passive pollution on the table in front of the same manikin were simulated. The performance of the ventilation systems was evaluated with regard to the quality of inhaled air and thermal comfort of the seated “occupants”. The walking person(s) caused mixing of the clean and cool air near the floor with the polluted and warmer air at higher levels and disturbed the displacement principle which resulted in a decrease of the inhaled air quality. The performance of the “ductless” PV under the tested conditions was better as opposed to DV alone. Thus in practice the “ductless” PV will be superior to DV alone as regards perceived quality of inhaled air. The location of a walking person was found to be important. Person(s) walking close to the displacement diffuser will cause greater disturbance.     

Biosphere reserves and the “Yucatán” syndrome: another look at the role of NGOs

After centuries of cultural and economic conquest of the Americas by European and Euro-American conquistadors, contemporary rhetoric in ex-colonial powers heralds the decline of material and ideological imperialism. Instead, it is purported that today's world is peopled by a great brotherhood, with the more affluent striving to relieve their less fortunate, underdeveloped kith. This conviction is inherent in organizations which dispense money, information, training, and other resources in the name of community development and endangered species and environmental conservation. What is rarely perceived – and practically never said – is that these “benevolent” foreign aid activities typically result in the concentration of resources and power in the hands of a few, the building of empires, and the compounding of already difficult situations, counter-productive to stated objectives. The Yucatán Peninsula is a classic case of persistent imperialism: the geographic name is a corruption of the Mayan “matan cub a than” (“I do not understand you”), while contemporary development and conservation programs habitually exhibit cultural ignorance and dominance. This paper explores a diverse literature on non-governmental organizations, reflects on likely consequences of cultural dominance, and implores professional anthropologists to be adventurous in propagating anthropological knowledge relevant to environmental protection.     

The “Landscape must become the law”—or should it?

The idea that society ought to be governed by the “law of landscape” must be seen in the context of the process by which the idea of landscape merged with that of nature in the course of the Renaissance and Enlightenment. In order to comprehend how these ideas morphed into the idea that “nature must become the law” as propounded by IFLA this history is traced. Through the linkages of “natural” social ideals with what was seen to be a “natural” style of landscape gardening, reforms sought to promote what often was seen to be a more just and economically, socially and physically sustainable form of society. This was an inherently conservative approach. It is shown how the ideas of landscape that developed from the Enlightenment to the period of land embellishment took a diabolical turn during the era of National Socialism in Germany. The idea of rooted-in-the-soil native plants as the ideal constituent of a German “landscape” continued among landscape architects and landscape planners after the liberation from National Socialism. Though somewhat diluted in the course of the second half of the twentieth century it re-emerged in a kind of renaissance in late twentieth and early twenty-first centuries under the terms “ecological planning” and the “nature garden”. Another source of these ideas lies particularly with the thinking of “anthroposophists”. The passage of a current legal landscape document, The European Landscape Convention, the heritage of the idea that “landscape must become the law” has gained new pertinence.     

Nitrogen elimination by rapid alternation of aerobic/“anoxic” conditions in “orbal” activated sludge plants

Methods of operation for obtaining maximum nitrogen elimination in the “Orbal” endless channel extended aeration plant are compared. The most efficient method required balancing of sludge concentration, organic load and oxygen input against one another in such a way that a rapid alternation of aerobic/anoxic conditions was brought about between aeration points in each channel. This resulted in minimal amounts of ammonia and nitrate remaining in the effluent. Automated control of oxygen input and of sludge concentration is considered necessary for consistent maximum nitrogen removal.     

The stabilization of “dissolved” iron in freshwaters

Laboratory experiments have been conducted to see what substances are capable of holding iron at a concentration of about 1 ppm in a “dissolved” form (i.e. will pass through a 0.45 μm pore size filter) in oxygenated water. The results show that reagents capable of doing this include humic and tannic acids, surfactants such as sodium dodecyl sulphate and sodium dodecylbenzene sulphonate, and the inorganic ions silicate and phosphate. In contrast, the synthetic polymer polyvinylpyrrollidone and the simple ions Cl⁻, HCO₃⁻, SO₄⁻ and NO₃⁻ showed no ability to stabilise iron. The efficiency of phosphate at keeping iron in the “dissolved” state was found to decrease in the presence of cations, particularly divalent ones, but increased with rise in water pH in the range 6–11.It seems unlikely that much of the stabilization observed for any of the reagents tested is due to their forming complexes with the iron. A much more likely explanation is that the substances for which positive results were obtained are able to stabilize fine colloidal iron particles and inhibit them from forming larger aggregates.     

Technology transfer projects in developing countries—furthering the Project Management perspectives

This paper attempts to broaden the analysis of the technology transfer phenomenon by refocusing research attention on the level of performance assessment of technology transfer projects. An holistic evaluation framework based on the considerations of an extended Project Life Cycle model is proposed to overcome some of the shortcomings of conventional approaches to project evaluation. This also reinforces the need for open systems thinking in assessing and managing risk of technology transfer projects. The discussion is based on two case studies which articulate the experiences with two integrated mechanisms of technology transfer used in Algeria from 1965 to 1990: turnkey and “product-in-hand”. The aim is to gain a better understanding of the processes of technology transfer and to contribute to the improvement of associated managerial practices in developing economies.     

Particulate forms of radium and barium in uranium mine waste waters and receiving river waters

A method of selective dissolution was used for analysis of particulate forms of radium and barium in a system consisting of uranium mine waste waters purified by coprecipitation with barium sulphate and of adjacent river waters. Four particulate forms of both the elements were distinguished: “loosely bound”, “acid soluble”, Ba(Ra)SO₄ and “in crystalline detritus”. It was found that the distribution of radium and barium between dissolved and particulate forms in waste waters depended on the time interval elapsing between the sampling and membrane filtration of the waters. No such dependence occurred in river water. The main particulate form of radium and barium in the system was Ba(Ra)SO₄. River water upstream of the mine water discharge contained radium mainly in “acid soluble” form or “in crystalline detritus” and barium as BaSO₄ or “crystalline detritus”. In unpurified mine effluents, a large part of radium and barium was present as “crystalline detritus”. Abundance of the “loosely bound” form was very low in all the samples analyzed. The bond of radium in bottom sediments was approximately the same as that in the solids suspended in waste waters. Suitability and accuracy of the selective dissolution method for analysis of surface and waste waters has been demonstrated by the analysis of the results and by radiotracer experiments.     

Pollution of the river rhine with halogenated organic compounds an investigation during a “Fliessende Welle”

In August 1982 and between 13 September–1 October 1982, during two “Fliessende Welle” surveys, about 400 R. Rhine water sample were taken. The total organic halogen contents of about 200 samples were analyzed by different methods. In waste water samples, as well as in river water samples, there were considerable differences in the analytical data depending on the method used. Some discharge points for organic halogens into the Rhine are identified.     

Etude de l'evolution de la qualite des eaux de riviere

In France, the creation of a “Ministère de l'Environnement et du Cadre de Vie” and “Agences Financieres de Bassin” has made it possible to obtain information on the water quality of rivers and on the measures necessary to improve water quality. Particularly in the Adour-Garonne Basin, much information is now available. The methodology needed to draw conclusions concerning the quality of the rivers and to show the effectiveness of control measures has been developed.This method has been tested in two catchments (Fig. 1): L'Adour (15,000 km²) and La Dordogne (24,000 km²). The steps that were necessary before this method could be used were: critical assessment of the available data; identification and measurements of pollution sources. This called for the collection of information, annual statistics for each sampling station and information concerning the value and importance of measured parameters.Detailed information is available from 1971 and 1976 and this is shown by maps and graphical representations of the variations in the value of different parameters (Fig. 2).Statistical analysis has also been carried out on the information available for the period 1971–1976.Two methods were used: analysis of the principal components, the method most used being shown by Figs 3 and 4 and the “STATIS” method developed recently which treats the whole data “At 3 indices” (Fig. 5).Research has been carried out on the causal relations between the water quality and the sources of pollution.A simple graphical method is proposed to explain the effect of a strongly preponderant pollutant source. It allows easy visualisation of the change in the relationship between two series of variables (Fig. 8).In general cases of several sources of pollution a simplified method using BOD exclusively has been developed. It consists in comparing the values measured in the river and the estimates obtained from inflows of various sources and those from upstream basins (Fig. 9).The application of this method has made it possible to distinguish local or general tendencies in reference to the intervention realised by the “Agence Financiere de Bassin”.Attention has been given to the variations obtained between laboratories and research information and the necessity to extend application of the statistical method to parameters other than BOD₅.Comparable action is being taken for the whole basin of the Rhone (French). The information obtained for “L'Adour and La Dordogne” has led to a study not only of the concentration of pollutants but two types of flow, with flow measurements and concentration being taken into account in order to eliminate hydraulic effects.     

Underground car parks: International case studies : ITA working group no. 13, “direct and indirect advantages of underground structures”

This paper summarizes the reports from members of the ITA Working Group “Direct and Indirect Advantages of Underground Structures” on underground parking conditions in various ITA countries.     

Non-experimental method of chemical analysis of metals-complex forming reagents solution in water

An essentially new method of chemical analysis was developed and named “the non-experimental chemical analysis”. The subject of the method is the qualitative and quantitative analysis of chemical properties of the system of complex forming reagents and central atoms. The method is based on the application of the general system equation. An application of the general system equation for the toxic system “cyanide-heavy metals” in water solutions is advanced.     

Probabilistic “φ = 0” stability analysis in strain-softening soil

A key issue in the improvement of geotechnical analysis and design is the assessment of safety and reliability. The value of probabilistic basis for risk assessment is now widely recognised. In this paper, attention is focussed on strain-softening behaviour which may be, and often is, overwhelmingly important for progressive failure. Other factors may also be significant but these are not dealt with here so that the formulation is simple enough to appeal to the geotechnical practitioner. After discussing the importance of strain-softening behaviour under undrained conditions, a method for determining the probability of failure is proposed so that widely available stability charts can be used. Peak and residual shear strengths (undrained) are regarded as the only random variables. The concept of “residual factor” is used to specify the proportion of slip surface which has passed from peak to residual shear strength. The progression of failure is seen in terms of an increasing proportion of the slip surface passing to the residual strength state. The proposed method is applied to an illustrative example using three different probability distributions or models.     

Travelling at 300 km/hour under the “Green Heart” of Holland — a tunnelling challenge

A beautiful piece of countryside, located in the western part of The Netherlands, is surrounded by the dense urban areas of four cities: Amsterdam, Rotterdam, Utrecht and Den Haag (The Hague). Because of its location and its rural beauty, this central park within the urban agglomeration of Western Holland is referred to as Holland's “Groene Hart” (Green Heart). About 600.000 people live in this area. Most of the land is countryside mainly used for agricultural purposes, such as dairy farms and marketgardening. The Green Heart is one of last remaining undisturbed natural landscapes in Western Holland. Fragmentation of this region will increase urban development and decrease the value of the scenic countryside. Considering these factors, the Dutch Government decided in April 1998 that the straightest possible route between Amsterdam and Rotterdam would be a shield driven tunnel under the Greene Heart to minimise nuisance and disturbance during the construction, as well as during future operation. This paper deals with the complex process of decision making, and reviews design aspects, research, construction, and project organisation, concluding with finance, public private partnership, and the planning of the shield-driven Green Heart Tunnel.     

Distribution and balance of volatile halogenated hydrocarbons in the water and air of covered swimming pools using chlorine for water disinfection

A survey of the “chlorination practice” of swimming-pool waters is presented taking the case of covered pools in Bremen. Chlorination of water may result in specific health hazards by various halogenated chemicals. Trihalomethanes (THMs), among others, are determined in water and air samples. We succeeded in identifying one organic “precursor” of the synthesis of THMs in swimming pools. An estimate of the average and maximum burden of the user/swimmer is given. Short and long range alternative measures are proposed to diminish the health hazards. We conclude from this work that the application of chlorine for disinfection should be minimized.     

Stability analysis of an underground power cavern in a bedded rock formation

An underground power cavern situated in bedded sandstone rocks was evaluated using the finite element method. The rock formation had a set of joints vertically with an opening of less than 0.1 mm. A “bedded model” was used to analyze the stability of the cavern excavation. The calculations were then checked by an “imitative model”. The results from these two models were consistent with each other. The results from the “bedded model” were similar to the displacements from the field measurements. The paper describes details of the numerical model, presents the results of the numerical calculations and discusses possible reasons for the similarities between the field measurements and results of the computations.     

Impact of western coal mining—I. Chemical investigations of a surface coal mine sedimentation pond

Chemical investigations of the sedimentation pond system at the West Decker Mine in southeastern Montana, U.S.A., were undertaken during an 18 month period from November 1975 to April 1977. Sedimentation pond water, essentially “altered” groundwater, differed chemically from the average groundwater in coal-bearing aquifers. The increase in certain chemical constituents (sodium, sulfate, bicarbonate and inorganic nitrogen) and the decrease in dissolved oxygen in pond water during autumn 1976 and winter 1977 was the result of erratic pond operation, dredging and increased nearby mining activity. Discharge from the pond complied with the guidelines advanced for effluents from surface coal mines. Levels of mercury in water samples collected from the sedimentation pond system were higher than those recommended for the protection of aquatic life and wildlife. The suitability of pond water for selected purposes and recommendations for improvement in pond design are discussed.     

Bound water content of biological sludges in relation to filtration and dewatering

This paper presents the results of an extensive analytical investigation on the mechanisms involved in filtration of biological sludges by studying the changes in the “bound water” content of activated and mixed digested sludges when they were subjected to several physical, and chemical processes. A new method for determining bound water in sludges, based on differential thermal analysis (DTA), was developed which proved reliable and fast. Water in sludges exist in two states, as “free” or bulk water and as “bound” water which is held by the solid state either by sorption on specific sites, i.e. functional groups of the proteins and other macromolecules and/or restricted within pores and capillaries. Water binding by sludge displayed similar behaviour to the absorption of ions.All chemical coagulants (FeCl₃, AlCl₃, FeSO₄) and cationic polyelectrolytes resulted in a reduction of the specific resistance and the bound water content of the sludge which was due to the replacement of water molecules by the adsorbed coagulant. Heat treatment of activated and digested sludge at 130°C resulted in a reduction of bound water by 30% whereas freezing and thawing reduced bound water by 70%.     

“Urban versus rural” no longer matches reality: an early public agro-residential development in periurban Santiago, Chile

The paper discusses the validity of the “urban versus rural” dichotomy in scientific literature, statistics and urban planning practice, especially in empirical studies developed around the issue of vegetable and animal farming inside and around cities. Santiago’s rural–urban interface is presented as a case study. Sample results extracted in early 2003 have shown that farming mixed with other land uses is even now a reality in Southern Santiago, supported in solidarity alliances and a characteristic life philosophy, giving researchers the possibility of exploring a living ecocity laboratory.     

Automated determination of carbon in natural waters

An automated method for determining inorganic carbon and organic carbon in water is described. The sample is acidified and the CO₂ from inorganic carbonate is removed in a packed column and measured with an i.r. analyzer. The stripped liquid is pumped to a furnace containing cobalt oxide catalyst at 950°C where the organic carbon is oxidized; the resulting CO₂ is measured with an i.r. analyzer. Operating as a “two-channel” system, inorganic carbon and organic carbon are measured simultaneously at 20 samples per hour. If used in a “single-channel” mode, inorganic and organic carbon are measured separately, inorganic carbon at 60 samples per hour, organic carbon at 20 samples per hour. The coefficients of variation at 1 and 5 mg l⁻¹ organic carbon are 5.1 and 2.8% respectively. The detection limit is 200 μg l⁻¹C.