The topic of this dissertation is the assessment of the black carbon in the soil. The soil samples were collected in the Brdy area. Relics of charcoal kilns from the 17th - 18th centuries occur there in some places. A part and parcel of this paper is the literature search of the black carbon in the soil, of the history of burning charcoal and of the general characterization of the site where the terrain measurements were in progress. The measuring specification is a part of this paper, too. The results showed changes of physical and chemical characteristics between original forest soils and soils enriched by the black carbon. These soils in the beech forest showed approximately pH 4,7, while soils in the spruce forest showed pH 3,7 on the average. Original soils in the beech forest were more acid by 1 pH unit, and the original soils in the spruce forest were by 0,3 pH more acid. The bulk density of the original soils was 1,28 g/cm3 on the average, and the soils enriched by black carbon decreased to 0,68 g/cm3 on the average. Key words: coal kiln, Brdy, Black carbon, Elementary soil area

Depuis le XXe siècle, les archéologues et les historiens se sont intéressés à l’emplacement des sites, aux structures et aux hommes spécialisés dans la production de céramiques et de matériaux de construction en Gaule. Les sources sont diverses : textes anciens, épigraphie, iconographie, comptes rendus des interventions sur les structures de production et études de mobilier.L’ensemble des données pour les IVe, Ve et VIe siècles a été rassemblé au cours de ce travail de cinq ans et demi. Une base informatique a notamment été construite pour définir les ateliers et les zones de productions avérés, incertains ou mal datés, en activité en partie ou sur toute la période étudiée (2055 notices).L’argile et le bois, ainsi que la proximité de grandes voies de communication sont des éléments décisifs pour comprendre l’installation et l’évolution de la plupart des ateliers. Néanmoins, d’autres facteurs interviennent : la présence de réseaux de négociants, la vitalité et l’évolution économique et politique de la région lors de l’implantation de l’atelier, ainsi que le statut des terrains d’installation et parfois des mesures législatives.Les structures artisanales et les techniques utilisées demeurent classiques sur les trois siècles étudiés. Toutefois, l’évolution de l’économie et de la consommation céramique entraine la diminution des dimensions des aménagements. De même, certaines structures sont désormais plus souvent utilisées, tandis que les fours, certains supports de soles, auparavant rares ou inédits, ont pu être mis en évidence. Certaines techniques de façonnage et de décoration, ainsi que des modèles de cuisson deviennent également plus courants.La densité des ateliers souligne l’importance et l’évolution politique et économique des régions au cours des siècles étudiés. La vitalité ou le déclin de l’artisanat céramique dans certaines régions coïncide ainsi avec les déplacements des points stratégiques de l’économie et du pouvoir politique en Gaule. / From the XX century, archaeologists and historians have been interested by the setting of archaeological sites, the structures and the people who specialised in the production of ceramics and tiles in Gaul. There are diverse sources : ancient texts, epigraphy, iconography as well as excavations reports, and the study of ceramics objects.Data for the IV to the VI centuries has been collated and studied during the realization of this thesis over five and a half years. A database was created to define the workshops and known productions areas, as well as those which are less well known or less well dated but which were at least partly active during the period studied. The database is composed of around 2055 records.The availability of clay and wood and the proximity of a navigable water course or a network of roads are clearly decisive factors in the setting of each workshop. However there are a number of other important factors: An active network of merchants, a positive economic and political context and sometimes regional or local legislation.The traditional artisanal structures and technics used remain unchanged between the IV-VI centuries. Overall, the evolution of the economy and the consumption of ceramics leads to a reduction in the size of these structures. Also the use of certain structures becomes more frequent. The kilns and supports for the soles, and ancillary structures, which are infrequently recorded and poorly understood, are discussed in this thesis. Certain technics and styles of fabrication and decoration become increasingly common.The density and frequency of the workshops underlines their economic and political importance and the evolution of the regions over the three centuries studied. The growth or decline of the ceramic production in some areas coincides with shifts in the centres of economic and political power in Gaul.

La présente thèse se place dans une dynamique de recherche générale ayant pour objectif de caractériser les productions des différents ateliers de céramiques antiques d'Afrique du Nord. Dans cette perspective, l'étude exhaustive des amphores produites à Zitha permet de mettre en lumière les spécificités de ses productions et de dégager une typologie propre à ses ateliers. Le parallèle établi entre les productions d'amphores de Zitha et celles des deux petits ateliers ruraux inédits d'Henchir Kalkh et Henchir Bou Gornine permet, en outre, de définir l'existence d'un faciès céramique à dominante tripolitaine propre à cette région de la Tunisie méridionale. Outre son intérêt typologique, ce travail vise également à intégrer ces données dans une dynamique plus globale et à s'interroger sur le potentiel économique de la Tripolitaine occidentale. Si les différents contextes de production étudiés (site de production semi-urbain et sites ruraux) nous amènent à nous interroger sur leur relation à une échelle locale et régionale, la production de types plus ou moins standardisés pose également la question de leur intégration au sein des réseaux commerciaux africains et méditerranéens. La présence, mais aussi l'absence, de certains types d'amphores caractéristiques suivant les différents ateliers de la province de Tripolitaine permettent également d'aborder la question de leur contenu (huile, vin, salaisons) et d'appréhender les différentes denrées produites sur ce vaste territoire. Il est ainsi possible de dégager certaines spécificités régionales au sein de cette grande province. / This thesis forms part of a dynamic research aimed at characterizing the productions of ancient ceramic workshops in North Africa. In particular, the exhaustive study of amphorae produced at Zitha highlights the characteristics of these products and permits to identify specific workshops typologies. Correlations can be drawn between the amphora production of Zitha and those of two other (unpublished) rural workshops, those of Henchir Kalkh and Henchir Bou Gornine. Moreover, this allows to define the existence of a dominant Tripolitania facies of ceramics, specific to this region of the southern of Tunisia. In addition to the morphological interest, this work also aims to integrate these data in a more global systematic and wants to reflect on the economic potential of the western Tripolitania. The different studied production contexts (both semi-urban and rural sites) can lead us to question their relationship to local and regional scale of craft activity, the production of more or less standardized morphologies and raises the question of their integration into larger African and Mediterranean trade networks. The presence, but also the absence, of characteristics types of amphorae in certain known Tripolitania workshops also helps to address the issue of content (oil, wine, cured meats) and to understand the various commodities produced on this vast territory. This research shows the potential of identifying various regional specificities in this important and large province of the Mediterranean world.

This work deals with modeling the flow of particulate matter in rotary kilns. For this purpose, a combined CFD and Discrete Element Method (DEM) model was used. Using Ansys Fluent software, several simulations were performed in order to determine the mean residence time and movement of the material in the rotary drum dryer. Results of the computational model were used to develop a regression model of the mean residence time and compared to the values as given by empirical equations. Furthermore, a simplified sensitivity analysis was performed for the selected input parameters of the model such as the stiffness constant, air mass flow rate and the particle size.

Portland cement-based products are the most commonly used building materials. However, it is well known that the production of OPC not only consumes a significant amount of natural resources and energy but also releases high quantity of carbon dioxide (CO2) to the atmosphere. Purpose of this work is to develop new cementitious material similar to Portland cement-based concrete, which is convenient in terms of energy and is environmental-friendly at once. This work presents preparation, composition and properties of inorganic aluminosilicate polymer, called geopolymer, synthesized from blast furnace slag and fly ash, activated by sodium hydroxide and cement kiln dust. Study of the microstructure was based on SEM-EDX-WDX, TG-DTA-EGA and XRD analysis.

The report investigates the feasibility of accessing waste heat at kiln 7 in the Cementa AB cement plant in Slite, Gotland. The background is provided, with a description of the cement manufacturing process. Most of the report concerns itself with the heat transfer capabilities of the plant, therefore a short description of the heat flow within the most essential equipment is provided. The investigation follows a set of steps to derive the conclusion. The first step investigates previous studies to obtain the three most feasible heat sources. The second step investigates the available heat of the selected sources. In the third step, accessing the source is discussed and investigated for both convection and radiation heat transfer methods. It also includes the sizing of the required heat exchangers. Using the new sources, the connection possibilities to existing infrastructure and its benefits are investigated in step four. The connections were made to the existing infrastructure used at kiln 8 for electrical generation and district heating supply. The selections of the most feasible solutions are provided based on heat recovery, payback period and practicality. The final step in the study provides for the final design, which consists of three possible connections or all of them combined. In the conclusion, the final design would provide for a reduction in oil burned, fuel consumption and CO2 emissions and an increase in electricity generated by the existing system. It is recommended that only one of the three connections be installed. / <p>The thesis was conducted at Cementa AB in Slite, Gotland. The supervisor at the plant was Fred Grönwall.</p>

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This thesis has determined that using fly ash as a mineral filler in asphalt pavements can help strengthen and reduce asphalt moisture damage. Also, dynamic shear rheometer tests show that these additives have a stiffening effect on asphalt binder. Moisture related damage is considered one of the main causes of asphalt pavement failure. As water infiltrates a layer of asphalt, it slowly strips away asphalt binder, weakening the aggregate/binder bond. This process, combined with the cyclic loading of traffic, can lead to several different types of asphalt failure including rutting, raveling, bleeding, and cracking. For several decades, research has been conducted to find a solution to this problem. Currently in practice, hydrated lime and a variety of amine-based chemicals are being used as anti-stripping agents. However, as an emphasis towards sustainability has increased, waste products are now being investigated for this purpose. This thesis investigated the anti-stripping effectiveness of two waste products: fly ash and cement kiln dust (CKD), and compared them with hydrated lime and an amine-based chemical additive. The results indicate that class C fly ash can be used as an asphalt anti-stripping additive; however it is more costly than lime or amine chemicals.

No description available.

No description available.