Search Results

You are looking at 1 - 7 of 7 items for

  • Author: Jerzy Trzciński x
Clear All Modify Search
Open access

Jerzy Trzciński, Małgorzata Zaremba, Sławomir Rzepka, Fabian Welc and Tomasz Szczepański

Abstract

The archaeological site Tell el-Retaba in north-eastern Egypt, about 35 km to the west of Ismailia city, is located in the middle of Wadi Tumilat, a shallow valley running from the Nile Delta to the Bitter Lakes, along which flows the Suez Canal. In ancient times the valley was a route between Egypt and Syro-Palestine, strongly fortified in the New Kingdom times (16th–11th century BC). Mud bricks were analyzed from two parts of the Wall 1 (core of grey-brown bricks and inner extension of green bricks) in a fortress which existed during the Ramesses II times. Grain-size composition of the studied bricks was almost identical in both parts of the wall, suggesting the same source material for a production of brick. However, significant differences were observed in physical and mechanical properties (uni-axial compressive strength) in both types of bricks. Bricks from the core had lower bulk density, higher porosity and soak faster, whereas their resistance parameters were much lower than those of the bricks from the inner extension. The reason for such large differences in brick properties was a technology of their production, particularly proportion of components, water volume added during brick formation or density degree. Brick preparation and in consequence, physical-mechanical properties had direct influence on preservation of defensive structures during environmental changes related to changes of groundwater and surface water levels or of precipitation. Ancient Egyptians responsible for construction works in mud brick structures of the fortress must have had good knowledge and experience. This could be observed particularly for the heaviest and most important construction element that is the defensive wall, founded on well-densified deposits. It was also testified by higher resistance of green bricks from the inner extensions, which probably originated slightly later and were intended to reinforce a weaker core built of grey-brown bricks.

Open access

Jerzy Trzciński, Małgorzata Zaremba, Sławomir Rzepka, Witold Bogusz, Tomasz Godlewski and Tomasz Szczepański

Abstract

The Tell el-Retaba archaeological site is located at Wadi Tumilat, a shallow valley running from the Nile Delta to the Bitter Lakes. In ancient times, a route connecting Egypt with Syria-Palestine ran across the site. In the 13th century BC, during the rule of Ramesses II, a fortress surrounded by “Wall 1” was erected and in times of Ramesses III in the 12th century BC, a larger fortress surrounded by “Wall 2” and “Wall 3” was constructed. Using the finite element method (FEM) and ZSoil 2D&3D software, the wall heights were modelled and their soil-structure interaction was analysed. Strength of the wall depended on size and strength of bricks and mortar, brickwork, wall shape and foundation. Ancient builders using mud bricks must have known from practical experience the essentials of a wall construction, in which the height to width ratio was at 1.75 to 1.85. Moreover, they must have related the engineering properties of the material with the height of the construction and its purpose. The width to height ratio must have been used and related by ancient Egyptians to the ground resistance. Modelling has shown that, at wall width of 5 m, the foundation would have lost its stability at wall height of 13–14 m and bricks from the lower part of the wall would be destroyed. According to the undertaken assumptions, in order to retain stability, the wall height must have been limited to about 8–9 m.

Open access

Fabian Welc, Radosław Mieszkowski, Sebastian Kowalczyk and Jerzy Trzciński

Abstract

This paper presents the preliminary results of ground penetrating radar sounding applied at the desert archaeological site in Saqqara (Egypt). The survey was carried out in 2012 within a project realized by Institute of Archaeology, Cardinal Stefan Wyszyński University in Warsaw and the Faculty of Geology, University of Warsaw. One of the key aims of the research was testing the application of ground penetrating radar to non-invasive surveys of desert archaeological sites. Radargrams obtained for area of so called the Dry Moat channel surrounding the Step Pyramid complex have shown the geological structure of its filling. It comprises among others debris-sand conglomerate of diluval origin characterized by a significant content of the clay fraction and clay minerals. Such lithological content strongly attenuate the propagation of EM waves, restricting the depth range of the GPR survey. The conducted geophysical prospection west to the Step Pyramid in Saqqara has confirmed the high applicability of the GPR method in non-invasive studies of vast architectural structures, such as the monumental ditch surrounding the Step Pyramid known as the Dry Moat. It should summarised that high horizontal resolution obtained during GPR survey is a result of local geological structure of the searched area, i.e. strong lithological contrast of the sediments filling the Dry Moat, which, depending on their mineralogical composition

Open access

Małgorzata Zaremba, Jerzy Trzciński and Fabian Welc

Abstract

The Tell el-Retaba archaeological site is located in the middle part of Wadi Tumilat, which extends along the north-eastern margin of the Nile Delta. It contains fragments of fortified and domestic objects of the ancient fortress and other constructions built of mud bricks. The establishment and functioning of the fortress is dated at the times of the reign of two great pharaohs, Ramesses II and Ramesses III (13th and 12th centuries BC). The grain size composition of the sediments used for mud brick production had significant influence on their physical and mechanical properties, which was used by the ancient Egyptians for the improvement of bricks. The finest fractions, clay and silt, which generally comprise clay minerals and organic matter played a significant role. These components significantly influenced the mud brick properties and resulted in a structural cohesion of the material. The second important component of mud bricks were coarse fractions – sand and gravel. The source of material used for brick production were the natural sediments located in the vicinity of the fortress, i.e. the Holocene lake clay and the Pleistocene gravel and sand of the gezira formation, deposited by a braided river. Clay sediments have a variable lithology as can be deduced from grain size composition of mud bricks and their properties. This variability was caused by a variable regime of the Nile, which supplied material to the lake basin. Geological studies were used to recognize ancient environment and morphology of the area, and to find clay, sand and gravel open-pits that existed in the area. The fortress site was selected optimally in relation to the landscape morphology and close vicinity of the source of basic material and water used for mud brick production. The area around the fortress was substantially transformed by humans due to settlement.

Open access

Fabian Welc, Jerzy Trzciński, Sebastian Kowalczyk and Radosław Mieszkowski

Abstract

Geophysical investigations in West Saqqara area were part of the archaeological fieldwork of the Polish-Egyptian Archaeological Mission during the campaign in 2012. The main purpose of geophysical prospection using the ground-penetrating radar (GPR) was to determine the location of potential underground sepulchral structures in Saqqara necropolis. During the GPR survey, optimal depth penetration was achieved due to dry rocks and monolithic structure of ancient cemetery. Using antenna of 100 MHz, the depth of penetration was up to 45 m and with antenna of 250 MHz, up to 15 meters. Three main groups of archaeological structures were identified: Greco-Roman sarcophagi and mummies, brick-stone chapels and accompanying burial shafts; mobile objects (solid rock blocks as fragments of tombs). One of the main goal of the GPR survey was to track the route of the western part of the Dry Moat, expressed by a wide and shallow depression spreading towards north-south. It suggests that Saqqara plateau is an ideal site for using GPR surveying technology.

Open access

Anna Bąkowska, Dobak Dobak, Ireneusz Gawriuczenkow, Kamil Kiełbasiński, Tomasz Szczepański, Jerzy Trzciński, Emilia Wójcik and Piotr Zawrzykraj

Abstract

The selected parameters of the Wartanian and Odranian tills, with relation to their spatial occurrence, grain size distribution, mineralogical composition, matric suction and other physical characteristics, are presented. The assessment of the lithogenesis and stress history on the microstructure is attempted. The comparison of the compression and permeability characteristics from field and laboratory tests has been performed. Laboratory consolidation tests carried out with up to 20MPa vertical stress, revealed two yield stress values, one in the range of a couple hundreds kPa, the other in the range of a couple thousands kPa. Based on those results, the reliability of the soil preconsolidation assessment, with the use of the two different methods is discussed. The aspect of the triaxial strength reduction under the dynamic loading of diverse frequency and amplitude is raised. The research results depict a variety of possible geological-engineering characteristics, under the divergent constraints scenarios, of compression or strength weakening origin. The effects of the specialized research program will widen the possibilities of physio-mechanical and structural characterization of soils for geological-engineering purposes.

Open access

Piotr Paluszkiewicz, Ewa Mayzner-Zawadzka, Włodzimierz Baranowski, Grzegorz Bręborowicz, Maciej Brzeziński, Grażyna Durek, Adam Dziki, Maria Czupryńska, Małgorzata Lipińska-Gediga, Magdalena Łętowska, Andrzej Mital, Elżbieta Nowacka, Magdalena Pychyńska-Pokorska, Jerzy Ratajczak, Jan Rogowski, Zbigniew Rybicki, Sławomir Sobieszczyk, Radzisław Trzciński, Marta Wawrzynowicz-Syczewska, Jerzy Windyga and Maria Wujtewicz

Recommendations for the Management of Trauma or Surgery-Related Massive Blood Loss

Exsanguination is an underestimated cause of treatment failures in patients with severe trauma or undergoing surgery. In some patients the primary dysfunction of blood clot formation is a direct cause of a massive blood loss. Patients without previous coagulation disorders are at risk of coagulopathy following intraoperative or post-traumatic bleeding, where the local haemostasis does not warrant bleeding cessation.

The aim of the study was to assess the therapeutic value of various components of a complex interdisciplinary approach, based on the opinion of the experts treating patients with massive bleeding.

Material and methods. The study was conducted by anonymous questionnaire, using the analogue representation of the argument strength. The results were analyzed based on the techniques of descriptive statistics. The argument was considered a key parameter, when the median value of strength was located in the highest quartile.

Results. It was found that the arguments of the highest strength for the risk of developing the posthaemorrhagic coagulation disorders are: loss of more than one third of blood volume, fluid therapy in an amount greater than 35 ml / kg, administration of more than 5 units of packed red blood cells, insufficient supply of fresh frozen plasma and platelets in proportion to packed red blood cells, severe acidosis and hypothermia. The most important tests for post-haemorrhage coagulopathy are: anatomically non-localized bleed, abnormal values of the standard coagulation parameters and fibrinogen level below 1 g / L. In the treatment of post-haemorrhagic coagulopathy the team of experts pointed out the benefits of antifibrinolytic drugs, concentrates of prothrombin complex and recombinant activated coagulation factor VII.

Conclusions. Multidisciplinary therapeutic management of bleeding patients is associated with employment of appropriate treatment methods to achieve the best possible outcome. Factors influencing the development of coagulopathy, the methods of diagnosis and proposed techniques of treatment may facilitate therapeutic decisions in bleeding patients requiring massive transfusion of blood components.