Environmental Engineering

""William Murdock used coal gas to light his house and office in Redruth in 1792; this was the first commercial application of gas in the world. Gas has been used ever since for commercial, industrial and domestic applications. Gas was first produced from coal and later on from oil until its replacement by natural gas in the mid 1970s. The conventional production of gas from coal is well documented; however, there was also another method of gas production which is less well known, this was called “producer gas”.

Producer gas plants started to become popular in the early 1880 and were in extensive use by 1910. As producer gas plants evolved from the first plant built by Bischof (figure 1) through to their demise in competition in the mid 20th century, many varied types evolved. Following Bischof’s early development of the gas producer the next major development was that of Fredrick Siemens who developed a combined gas producer and regenerative furnace in 1857. This system was gradually improved and introduced to the UK through William Siemens. Producer gas plants provided a great benefit to those industries requiring high and uniform temperatures. This greatly aided those industrial processes which were unable or found it very difficult to use directly fired solid fuel furnaces, it also saved fuel as the gas could be burnt at the exact point required.

If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com."

usine à gaz, officina del gas, gasværk, gasfabriek, Gaswerk, εργοστάσια αερίου, gázművek, ガス工場, gasskraftverk, gazownia, gasômetro, газовый завод, плинара, plynáreň, plinarn, gasverk, fábrica de gas, havagazı fabrikası, газовий завод, 煤氣廠"

"Gas was manufactured continuously in the UK between 1792, when William Murdock first used coal gas to light his house and office in Redruth and the mid 1970s, when it was replaced by natural gas from the North Sea. One particular aspect of gas manufacture which has often been overlooked was the use of gas in remote country houses. These large properties were often expensive to light using oil lamps and candles, with their owners often keen to have the most up to date technologies used where possible to show their wealth. Coal gas lighting was much cheaper to use than candles or oil lamps and being fixed were relatively safe and actually resulted in lower fire insurance premiums when fitted.

As these sites were remote they were not able to connect to local gas mains and their only option was to build a small gasworks of their own. These small gasworks were very much in line with the philosophy of William Murdoch who proposed the use of small gas plants at individual establishments rather than that of Fredrich Winsor, who proposed the concept of large gasworks with gas distribution mains supplying towns and cities.

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If you have any specific enquiries on this subject please contact Dr Russell Thomas on thomasru@pbworld.com."

usine à gaz, officina del gas, gasværk, gasfabriek, Gaswerk, εργοστάσια αερίου, gázművek, ガス工場, gasskraftverk, gazownia, gasômetro, газовый завод, плинара, plynáreň, plinarn, gasverk, fábrica de gas, havagazı fabrikası, газовий завод, 煤氣廠

1st paragraph:

At the beginning of the twenty first century the number of city-dwellers and rural folk has equalled for the first time in human history. However, in the next 30-40 years it is expected that on average two thirds of mankind will live in towns and cities. In the most developed countries the number of urbanites will surpass 95% of all citizens, which will create a new society uprooted from earlier rural connections which were still visible in the nineteenth and twentieth centuries. In the long history of human kind the situation is relatively new and the drastic transition from a familiar and limited space of a village or town district inhabited by communities (of knowers), we have entered a new city-space environment of poorly bound communities or previous-era ghettos. Those new spaces together with a rapid development of service and industrial sectors as well as enormously inflated legislation on town planning and proper behaviour create a situation where a multitude of signs of various origin and purpose coexist side by side in a cacophony of colours, sounds, and shapes. Nevertheless, urbanites of the last few decades who travel around the world find it relatively easy to manage and navigate those new spaces despite their superficial differences. Therefore, there seems to be a growing need for a thorough discussion of urban spaces and urban signs thanks to which the plethora of messages as well as meanings and interactions could be approached and explained in a manageable paradigm.

"Contemporary visions of nature have been deeply affected by the ongoing interaction and interpenetration of science, nature, and society. These new visions appear to be more complex than older visions of nature and at the same time they seem to challenge our notions of authenticity.
"New Visions of Nature" focuses on the emergence of these new visions of complex nature in three domains. The first selection of essays reflects public visions of nature, that is, nature as it is experienced, encountered, and instrumentalized by diverse publics.  The second selection zooms in on micro nature and explores the world of contemporary genomics. The final section returns to the macro world and discusses the ethics of place in present-day landscape philosophy and environmental ethics.
The contributions to this volume explore perceptual and conceptual boundaries between the human and the natural, or between an ‘out there’ and ‘in here.’ They attempt to specify how nature has been publicly and genomically constructed, known and described through metaphors and re-envisioned in terms of landscape and place. By parsing out and rendering explicit these divergent views, the volume asks for a re-thinking of our relationship with nature."

This paper reviews developments in hybrid light guidance systems. In these daylight and electric light are simultaneously delivered into a building where they are combined and distributed via luminaires. The technology used in hybrid systems, both conceptual and realised, is discussed. The review speculates as to their likely performance in terms of daylight delivery; capital and running costs; user reaction to the systems; potential impact of the systems on the building which they light; and suitable design methods. It is noted that a substantial amount of work remains before the potential of hybrid systems may be realised, notably on their long tern economics and feasibility in different geographic locations.

Hybrid systems simultaneously deliver daylight and electric light into a building where they are combined and distributed via luminaires. Hybrid technology, both conceptual and realised, is discussed together with that of the more established of tubular daylight guidance lighting systems. Likely system performance in terms of daylight delivery and potential electricity savings is evaluated for different geographic locations throughout Europe. The results are discussed in relation to likely costs and potential impact on the building which they light.

A key requirement for Veeder-Root’s Enhanced Leak Detection System is that it be able to test in situ for the presence of leaks at gasoline dispensing facilities. Aside from the obvious issues of safety and lost product, this functionality is obligatory for compliance with environmental standards mandated by federal and state oversight bodies, such as the California State Water Resources Control Board (SWRCB). The SWRCB demands a testing procedure that includes conditions as close to operational as possible, while still using environmentally safe gases as a test fluid. Although the test parameters (e.g., pressure) are allowed to deviate from operating conditions in order to facilitate the test procedure, a prescribed rescaling of the test thresholds must then be applied to account for the deviation. Whether the test is run at operation conditions or in a slightly different parameter regime, the fact that the testing must be done on the product and return lines after installation at a service station presents significant challenges in devising an effective test strategy.

The formulation of policies requires the selection and configuration of effective and acceptable courses of action to reach explicit goals. A one-size-fits-all policy is unlikely to achieve the desired goals; as a result, the identification of a suite of alternative policies, together with clear indications of their trade-offs, is crucial to accommodate the diversity of stakeholders’ preferences. At present, the formulation of transport policies is done manually; this fact, together with the size of the space of possible policies, results in a large part of that space being left unexplored. A six-step framework to explore the space of alternative transport policies in order to achieve environmental targets is proposed. The process starts with a user-defined set of specific policy measures, using them as building blocks in the generation of alternative policy packages, clusters and future images according to the user's preferences and goals.The analysis framework is based on the visioning and backcasting approach used in the VIBAT report [Banister, D., & Hickman, R. (2006a). Visioning and backcasting for UK transport policy (VIBAT) project. Department for Transport's Horizons Research Programme 2004/06. The Bartlett school of planning and Halcrow Group Ltd. Retrieved 1/18/2008 http://www.ucl.ac.uk/∼ucft696/vibat2.html]. The framework is being implemented as a prototype decision support system around a case study: the formulation and analysis of policies required to achieve CO2 emission targets for the transport sector in the UK. Important insights on how to develop the framework have also been elicited from engineering design. The goal is to accelerate the task of policy-making and improve the effectiveness of the resulting policies.The proposed method and computer implementation is fundamentally different from the tools commonly used in the transport sector and is intended to assist (not replace) transport policy makers, and complement (not substitute nor compete with) existing mathematical modelling tools. This research constitutes the first step towards the development of a general family of computer-based systems that support the design of policies to achieve environmental targets—not only for transport, but also for other sectors such as energy and water.

La sostenibilidad del actual modelo de producción y consumo de biocarburantes constituye un tema de plena actualidad y debate a nivel internacional. Mientras en la mayoría de los países desarrollados se apoya a nivel institucional el fomento de su consumo y producción, principalmente por medio de medidas tales como obligaciones en el porcentaje de mezcla de los carburantes, incentivos fiscales a la producción y subvenciones agrarias, numerosas voces están surgiendo en contra del desarrollo de los mismos. Como consecuencia, se ha generado una diversidad de opiniones en defensa o en contra de los biocarburantes, cuyas raíces se pueden encontrar en las repercusiones ambientales, económicas y sociales que la expansión de los mismos puede desencadenar. A nivel europeo, el biodiésel, sustituto y complemento del diésel, representa el 72% del consumo de biocarburantes mientras que el bioetanol, sustituto y complemento de la gasolina, representa el 28%. A nivel español, por el contrario, el biodiésel se encuentra aún en fase inicial de expansión, con un 32% del porcentaje de consumo de biocarburantes en 2006, presentando un importante potencial de desarrollo en los próximos años. Precisamente, esta investigación aborda el estudio de la sostenibilidad del modelo de producción y consumo de biodiésel en España.
En este contexto, el objetivo del presente trabajo es doble: (1) Identificar las principales repercusiones ambientales, económicas y sociales derivadas de la producción de la biomasa en los sistemas agrícolas, de la obtención del aceite y su transformación en biodiésel, y de su consumo; (2) Delimitar y cuantificar la prioridad de los objetivos que habría que alcanzar para lograr un desarrollo sostenible de los biocarburantes teniendo en cuenta la triple dimensión ambiental, económica y social. Para alcanzar el primer objetivo, se ha realizado una revisión exhaustiva de la literatura internacional, clasificándose las repercusiones del uso del biodiésel según su naturaleza (ambiental, económica y social) y la fase en que se producen (agricultura, industria y consumo). Para alcanzar el segundo objetivo, se ha aplicado una técnica de decisión multicriterio (ANP) basada en los juicios de un grupo de expertos en sostenibilidad de los sistemas agrarios. Esta técnica permite cuantificar los objetivos de sostenibilidad del modelo de producción y consumo de biodiésel en España, teniendo en cuenta los trade-offs e interrelaciones entre dichos objetivos, que en muchas ocasiones se encuentran enfrentados.
Los resultados indican que para alcanzar la sostenibilidad del modelo de producción y consumo de biodiésel son objetivos prioritarios en la dimensión ambiental la “Conservación de recursos no renovables”, en la dimensión económica la “Facilidad de implementación técnica en su producción, almacenamiento, distribución y consumo” y en la dimensión social la “Generación de empleo directo (en el sistema agroenergético)”.

We have developed a simple method to create a catalyst with atomically dispersed Pt on top of Co nanoparticles on single walled carbon nanotubes (SWNT) supports by sequential impregnation of Pt(II) and Co(II) solutions following by hydrogen reduction. The aqueous phase reforming activity is much higher than for Pt monometallic catalysts on SWNT supports prepared by several methods, either prereduced in hydrogen or in the liquid phase. The high selectivity of the monometallic catalysts is maintained for the bimetallic systems. The Extended X-ray absorption Fine Structure (EXAFS) results at the Pt LIII edge show no observable Pt–Pt bond. Only Pt–Co bonds were observed, indicating high dispersion of Pt. The enhanced activity comes from two sources: the high dispersion of Pt and the effect of the Co as co-catalyst or modifier. This contribution demonstrates the possibility to further engineer bimetallic catalysts to improve the aqueous phase reforming activity, especially to retain good selectivity at high conversion.

Jute stick powder (JSP) has been found to be a promising material for adsorptive removal of congo red (C.I. 22120) and rhodamine B (C.I. 45170) from aqueous solutions. Physico-chemical parameters like dye concentration, solution pH, temperature and contact time have been varied to study the adsorption phenomenon. Favorable adsorption occurs at around pH 7.0 whereas temperature has no significant effect on adsorption of both the dyes. The maximum adsorption capacity has been calculated to be 35.7 and 87.7 mg/g of the biomass for congo red and rhodamine B, respectively. The adsorption process is in conformity with Freundlich and Langmuir isotherms for rhodamine B whereas congo red adsorption fits well to Langmuir isotherm only. In both the cases, adsorption occurs very fast initially and attains equilibrium within 60 min. Kinetic results suggest the intra-particle diffusion of dyes as rate limiting step.

The water we drink should be safe. The cryptosporidiosis outbreak in Galway in 2007 reminded us that it sometimes is not. But bad water quality does notonly cause acute health problems. It also causes chronic ailments, including cancer. Therefore, the drinking water quality is monitored by the City andCounty Councils, overseen by the Environmental Protection Agency (EPA). A recent paper by Tol et al.,examines the quality of drinking water in Irelandover time

Various options in biotechnology have been exercised to produce industrially important metabolites from filamentous
organisms. To select a suitable production strategy, the direct and indirect roles of morphological parameters in
controlling bioprocess variables are observed. Some progress has been made in quantitation of morphology.Useful correlations
have been reported in the literature in this avenue. Of course, some of the models, with proper modification, can be
used to explain the morphological phenomena. This review is concerned with the application of morphological variables
to correlate with bioprocess parameters for explaining optimal production strategy.

Most of today’s environmental policies in Brazil rely on controlling the growth of pollution by “command and control” techniques. During the last two decades, these instruments have been designed to control sources of environmental impacts using industrial zoning, environmental licensing, and emission standards. The present structure of environmental law and policy focuses almost entirely on the activities of manufacturing companies and does not recognize strategies related to pollution prevention and/or cleaner production — such as product life cycle assessment, environmental labeling, environmental management systems, interconnectivity of production process, extended producer responsibility strategy, and environmental certification — as important instruments for auto-regulation. Recognizing that environmental policy must become more focused on “command and covenant” than “command and control”, this article attempts to provide an expanded perspective of environmental policy innovation based on a more holistic approach — Industrial Ecology — as a strategic tool for environmental policy-making process in Brazil.

The use of groundwater models is prevalent in the field of environmental science. Models have been applied to investigate a wide variety of hydrogeologic conditions. More recently, groundwater models are being applied to predict the transport of contaminants for risk evaluation.

With the increase of snow depth the most frequent is the circulation characterized by the air inflow from the north-west and the west, while with the decrease of the depth it is the cyclonic circulation characterized by the air inflow from the west. When the snow cover does not change its depth, most often it is connected with type Ka and the anticyclonic eastern type.
The appearance of the cyclonic type from one of the northern directions increases the probability of the growth of snow depth 2 – 3 times in relation to the probability defined with no information about the type. On the other hand, when the probability of a drop in snow depth is determined, the increase of this probability with added information about the appearance of a circulation type is slight. The probability reaches the greatest value with anticyclonic western circulation. The greatest probability of the snow cover occurrence with the same depth appears with anticycylonic circulation from east and south-east.

Key words:
atmospheric circulation type, snow cover, Carpathians, Bieszczady

"At the end of their service life, wood-based panels become eventually waste wood. Deploying in landfills is no longer considered as an acceptable solution for their handling due to the high organic load included. The recycling of this waste to be employed as raw material for the wood panel industry, which traditionally makes use of wood processing residues, has hence gained more importance and been examined from earlier times.
Technical problems and the lack of enforcing legislative regulations have delayed, however, the industrial implementation of the new technologies proposed. Recent research efforts
enabled the development of a new process for the recycling of end-use wood panels into new marketable fibreboards. This patent pending process is based on the refiner technique and
allows the use of mixtures of fresh wood and waste panel chips as a raw material for dry process fibreboard production. The process is applicable in existing fibreboard plants with only minor operation modifications and therefore, there is no need of major capital investment in additional equipment to effect the recycling. At the refining stage, chemical agents are employed and the process enables the use of significant amounts of waste
material replacing over 20% of the wood feed and providing significant savings. The aim of the present work was to validate the industrial applicability of the new process in the recycling of waste medium-density fibreboards. The new fibreboards obtained during the industrial scale tests were of acceptable quality, and the testing results revealed that under
conventional gluing and pressing conditions, the process effectively recycles the waste boards into new ones at least at 25% wood substitution level. Further validation and
optimisation work is underway in the direction of using other waste panel types and also increasing the level of waste in the feed material."

Engineering design is a knowledge intensive activity. Design is characterized as comprising a number of phases from requirements to detailed specification. Transitions between the design phases stem from decision-making processes supported both by generally available domain and design knowledge and from unique and original knowledge worth of recording for future reuse. The Clockwork project addresses the problems of representing, sharing and reusing knowledge in a collaborative design engineering environment. The Clockwork knowledge management methodology is supported by a web-based toolkit that allows designers to share, formally and informally annotate and reuse engineering models. Reuse is supported through the semantic search of engineering models and of the design rationale by which the engineering models were developed. The approach has been successfully deployed in two industrial organisations.

"Research efforts enabled the development of a new
process for the recycling of end-use wood panels into
new marketable fiberboards. This patent-pending
process is based on refiner techniques and allows the
use of mixtures of fresh wood and waste panel chips
as a raw material for dry-process fiberboard production.
The process is applicable in existing fiberboard
plants with only minor operation modifications. At
the refining stage, chemical agents are employed and
the process enables the use of significant amounts of
waste material replacing over 20 percent of the wood
feed and providing significant savings.The aim of the
present work was to validate the industrial applicability
of the new process in the recycling of waste fiberboards.
The new fiberboards obtained during the industrial-
scale trials were of acceptable quality.Testing
results revealed that under conventional gluing and
pressing conditions, the process effectively recycles
the waste boards at a wood substitution level of at
least 25 percent. Further validation and optimization
work is presently underway in the direction of using
other waste panel types and also increasing the level
of waste in the feed material."

"The conventional strawboard technology employing MDI binders has shown technical and economical disadvantages,specifically, high resin costs and additional costs related to release agents required to avoid sticking of panels to press plates. The adhesion of urea formaldehyde (UF) resin to the straw fiber has been demonstrated in a previous research project using an innovative chemi-thermo-mechanical (CTM) pre-treatment of the straw. This work focuses on the joint efforts to develop a strawboard technology based on UF resins. Three different straw preparation systems, a twin-screw extruder, a pressurized refiner and a combined extruder-refiner treatment, have been chosen to apply intensive shear forces to straw chips in order to overcome the wax and silica layer. With the first two technologies, one-layer panels exclusively bonded with UF have been produced. The board characteristics included excellent appearance, surface smoothness, machinability, edge appearance as well as good bending properties. The internal bond strength values achieved were compatible to particleboard standards. The swelling characteristics did not meet the European standard requirements. With the combined extruder-refiner technology, the UF bonded boards produced showed similarly excellent visual characteristics, bending and internal bond strength values exceeding the MDF standard requirements and swelling figures close to particleboard and MDF standards. By bonding with UF resins, good mat stability, a pressing
process without sticking problems and significant resin cost savings can be achieved. The forthcoming development work will be focused on further improvement of the adhesion of straw fibers to produce even higher quality strawboards."

"The rate and maximum swelling of several North American wood species in water have been obtained with a computer interfaced linear variable displacement transformer. Since wood swells extremely fast in water even at room temperature, this apparatus made it possible for the first time, to obtain accurate rate data on the swelling of wood in water. The strict linear dependence of swelling on the temperature suggests a chemical mechanism.
The activation energies obtained from Arrhenius plots ranged from 32.2 KJ/ mole for sitka spruce to 47.6 KJ/ mole for sugar maple. Although the two hardwoods exhibited greater maximum tangential swelling compared with the two softwoods, the maximum swelling appears to be correlated with the wood density. Generally both the rate and maximum swelling of the woods were increased by removal of extractives and the activation energies were reduced."

Chahardouly basin is located in the western part of Iran and is characterized by semi-arid climatic conditions and scarcity in water resources. The main aquifer systems are developed within alluvial deposits. The availability of groundwater is rather erratic owing to the occurrence of hard rock formation and a saline zone in some parts of the area. The aquifer systems of the area show signs of depletion, which have taken place in recent years due to a decline in water levels. Groundwater samples collected from shallow and deep wells were analysed to examine the quality characteristics of groundwater. The major ion chemistry of groundwater is dominated by Ca 2C and HCO 3 , while higher values of total dissolved solids (TDS) in groundwater are associated with high concentrations of all major ions. An increase in salinity is recorded in the downgradient part of the basin. The occurrence of saline groundwater, as witnessed by the high electrical conductivity (EC), may be attributed to the long residence time of water and the dissolution of minerals, as well as evaporation of rainfall and irrigation return flow. Based on SAR values and sodium content (%Na), salinity appears to be responsible for the poor groundwater quality, rendering most of the samples not suitable for irrigation use.

L’essentiel des ressources en eau de la Côte d’Ivoire est contenu dans les aquifères formés par le socle fracturé. Il importe donc de mieux connaître ces aquifères fracturés car leur importance hydrogéologique est considérable. C’est dans cette perspective que s’inscrit la présente étude qui couvre la « Région des Montagnes » de l’Ouest de la Côte d’Ivoire. Le principal objectif de cette étude est une meilleure caractérisation des aquifères fracturés : quantification de l’organisation des réseaux de fractures. L’analyse de la fracturation a été conduite sur deux types de cartes : cartes extraites des photographies aériennes et des images satellites. Elle s’est appuyée sur les méthodes d’analyse géostatistiques. Les résultats montrent que les variogrammes de la fracturation globale sont structurés. Ils sont caractérisés par une portée, un plateau et un effet de pépite. Les variogrammes des familles de fractures indiquent aussi une structuration mais les familles NESW et NW-SE de la carte1 présentent un pur effet pépite. L’effet de pépite est dû à l’action combinée des erreurs de mesure et une microrégionalisation. Ces résultats indiquent que la fracturation se comporte comme une variable régionalisée. La structuration des variogrammes est meilleure sur la carte 2 (images satellites) que sur la carte 1 (photographies aériennes). La cartographie de la fracturation par les images satellites apporte des informations plus détaillées que celle par photographies aériennes.

Mot-clés : Fracturation, photographies aériennes, images satellitaires, géostatistique, variogramme, Man-Danané (Côte d’Ivoire)

The aim of this paper is to identify and map the risk of flooding areas in the semi-mountainous region of Côte d’Ivoire. This work is based on the integration within a GIS of data interpreted from Landsat TM imagery, image based on a digital elevation model (DEM), and hydroclimatic data. The processing steps, using remote sensing and GIS softwares, include : 1) DEM building with contour level extracted from topographic map, 2) determination of morphometric variables using DEM, 3) processing of Landsat TM imagery and thematic mapping, and 4) integration of the different layers deduced from satellite data, DEM and its derived data, complementary data and spatial analysis within a GIS. The main flooding risk factors are : rainfall, land cover, rivers network, slopes, lithologic and structural domains. Multicriteria spatial analysis into a GIS allowed mapping the hazards and the vulnerable areas. The integration of these layers allowed mapping the flooding risk of this study area of Côte d’Ivoire. The resulting map shows four clusters varying from low to very high flooding risk. The risk of mean and high flooding is about 65 % of the whole study area and concern alluvial area of southern, and toward the principle rivers : Sassandra (in the western) and Bafing (in the northern). The large extension of vulnerable flooding areas imposes us to take it into account to predict flooding risk and to manage natural resources in the Man region (western of Côte d’Ivoire).

Keywords : Remote Sensing ; GIS ; DEM . hazard ; flooding risk ; Côte d’Ivoire.

Automated collection of environmental data may be accomplished with wireless sensor networks (WSNs). In this paper, a general discussion of WSNs is given for the gathering of data for educational research. WSNs enhance the scope of a researcher to include multiple streams of data: environmental, cyberdata, video, and RFID. A brief overview of the technology prepares the exploration of a setting used for outdoor learning.

This paper elaborates on the chemical composition of wastewater at
selected Wastewater Treatment Plants (WWTPs) in Jordan. These plants have
immense potential of providing reused treated water for irrigation. Samples
from treated effluents analysed to study the efficiency of the impact of treated
water on irrigation. The results revealed the effluents from WWTPs could be
used for irrigation with special consideration of the possible acceleration of soil
deterioration, while those of other WWTPs could be used with less concern for
selected crops. The study also shows that no other toxic ions, such as lead,
nickel, chromium and boron, were detected.
Keywords: wastewater management; water resources management; water
reuse; environmental management resources; irrigation; wastewater treatment
plants; agriculture in arid and semiarid areas.

This study aims to apply the ultrasound technique in the
field of clean technology to protect environment. The principle
of ultrasound was conducted here to study the effect of applying
high frequency of ultrasound waves. Four kinds of water
namely; Seawater from Aqaba gulf, Red Sea, brackish from
Maan desert southern part of Jordan, hot spring from northern
part of Jordan and tap water (Amman City) were selected to
study the effect of ultrasound on its physical properties. High
ultrasound frequency device with 1.7 MHz was applied to
study the effect of ultrasound waves. All conducted experiments
were fixed at room temperature. The effect of liquid volume
while applying a constant ultrasound waves on the water properties
were investigated here. Exposing time of ultrasound
waves was fixed at 0.5, 1.0 and 1.5 h. The experimental
results showed that ultrasonic wave irradiation for different
samples of water at different period of time has its significant
impacts on physical and chemical properties of water such as
pH, total dissolved solids and consequently the conductivity.
Key Words: High frequency ultrasound, Total dissolved
solids, Water desalination, Water treatment, Environmental
protection, Physical properties.

In this paper the fly ash, which is the finest residue of the lignite combustion entrapped by electrostatic filters at the electrical power stations, is examined, in order to determine the possibility of its usage in the production of concrete. It is implemented by testing concrete models in actual scale. Mineralogical, petrographical and chemical analyses of the fly ash as well as of the produced concrete are presented. The concrete that was produced by cement, sand, water, aggregates and fly ash (in various percentages) showed micro-cracks in its structure, due to the reduced interconnection of the fly ash with the aggregates. Nevertheless, the fly ash may act as adhesive material, as well as the material that fills the cracks of the concrete. Tests of the strength on models made by this concrete have shown comparable results in strength with reference concrete produced without ash. It is concluded that the mixing of fly ash in concrete does not affect its strength and sometimes it fills the cracks of the concrete mass.

Μελέτη της δυνατότητας χρήσης ιπτάμενης τέφρας στο σκυρόδεμα.

Paper in the Ash Library (http://www.flyash.info/) in the web http://www.flyash.info/2005/15kou.pdf .

The aim of the present paper is to review a novel modular constructional element for the building and construction industries that was patented by Coventry University. Modular elements have been used in the past in the construction of structures in order to speed construction and cut on time and cost. The modular element, the subject of this study, comprises hexagonal elements made of steel or other appropriate material, assembled together to form a constructional assembly of honeycomb form secured by fixings that clamp together the sides of adjacent elements. Concrete, or other appropriate material, is disposed within the elements providing a composite type of action. Reinforcement is also present in the form of bars or tubes, providing extra strength to the assembled element. The novel type of modular construction has potential applications in the building, construction, substructure and highways sectors. It could be used as a permanent or temporary structure for roofs and walls. It may also be used for concrete pavements, tunnelling, and retaining wall structures.

In this paper, we consider economies in which agents are privately informed about their skills, which evolve stochastically over time. We require agents'preferences to be weakly separable between the lifetime paths of consumption and labor. However, we allow for intertemporal nonseparabilities in preferences like habit formation. We show that such nonseparabilities imply that optimal asset income taxes are necessarily retrospective in nature. We show that under weak conditions, it is possible to implement a socially optimal allocation using a social security system in which taxes on wealth are linear, and taxes/transfers are history-dependent only at retirement. The average asset income tax in this system is zero.

Each tree is unique because of the physical environment it experiences over the course of its life. Environmental factors shape a tree within the bounds of its genotype. Only by modeling the environmental influences can we create realistic models of trees. To this end, we constructed a structural simulation that calculates the mass of each branch of the tree to emulate the mechanisms the tree uses to balance its weight, and that estimates the photosynthesis return of the leaves to simulate phototropism. Our effort is motivated by a desire to construct a predictive tool that can be used by both those in computer graphics and forest management, with applications in image synthesis, dendrochronology, mensuration and the simulation of forest succession.

Much of the responsibility for reporting on surface water quality in South Africa rests with the Institute for Water Quality Studies (IWQS) of the Department of Water Affairs and Forestry, geographic information systems (GIS) provide a means to summarize large amounts of spatially and temporally distributed data in an intelligible form. GIS developments at IWQS have progressed along two paths, application-specific tools and a general "data mining" system for querying water quality data. Applicationspecific tools include utilities for cataloguing monitoring stations, checking monitoring frequency and mapping the water quality in village boreholes. The general system, "WaterMarque", is a menu-driven front end to a suite of GIS macros and C programs. "WaterMarque" allows the water quality expert to select monitoring stations interactively and analyse the chemical data. The results are reported symbolically on a map, as box and whisker plots, rose diagrams, ionic diagrams, star symbols, time series graphs or icons.

The problem of pollution caused by heavy metals such as: Pb, Zn, Cu and Cd is very important,
because they may adversely affect soil ecology, agricultural production and water quality.
Contaminated soils and waters often present an unacceptable risk to human and ecological health
and must be remediate. These heavy metals are found in objects commonly used as paint, batteries
gasoline, industrial activities, agricultural and urban activities.
The most important problem is their bio-availability and consequently their immobilization. The
existing remediation technologies are considered expensive and often ineffective. Development of in situ
treatment technologies or effective volume reduction technologies, will provide a significant cost saving.
The aim is to isolate contaminants, to minimize further movements and reduce their solubility, as the
more mobile is the metal and the more risk associated with it.
In situ immobilization seems the suitable one, it means to transform these heavy metals in more
stable and less soluble compounds. In particular, phosphates show these characteristics and apatite has the
most suitable characteristics of immobilization for these heavy metals. The immobilization is through the
dissolution of apatite and precipitation of pyromorphite. Hydroxyapatite, Ca10(PO4)6(OH)2, as the
possibility to immobilize bivalent ions like: Pb, Zn, Cd, Cu, Cr and Ni and so on (Suzuki et al., 1981,
1984; Peld et al., 2004; Corami et al., 2005). The immobilization mechanisms are many such as: ion
exchange, precipitation of a complex ion-phosphate, dissolution and precipitation of a new mineral, in
fact it is hard to discriminate among each mechanism.

The transportation sector is one of the largest sectors contributing to Greenhouse Gas (GHG) emissions, the gases which cause anthropogenic climate change. The aviation and maritime shipping sectors are growing segments of transportation GHG emissions, yet mitigation strategies have largely avoided these sectors. There is a need for clearly defined strategies which can reduce GHG emissions of maritime and aviation operations and for an understanding of the potential magnitude and barriers to reduction. This research presents a framework for GHG emission reduction strategies and evaluates their reduction potential for maritime and aviation operations.