Search Results

You are looking at 91 - 100 of 284 items for :

  • "limestone" x
  • Refine by Access: All Content x
Clear All

Abstract  

Simultaneous thermogravimetry (TG) and differential thermal analysis (DTA) were applied to light crude oil combustion in the presence and absence of metal oxide. In crude oil-limestone mixture, three main transitional stages are detected. These are distillation, low-temperature oxidation (HTO) and high temperature oxidation (HTO) regions respectively. In the case of experiments with Fe(III)-chloride at different amounts, the shape of TG-DTA curve is changed considerably. Kinetic parameters of the samples are determined using ASTM method. Reduction in activation energy is considered to be an indication of the catalytic activity of the additive.

Restricted access

Abstract

In June 2003 Hungary accepted the European Standard for Aggregates for Railway Ballast (MSZ EN 13450: 2003). The European norm, compared with the Hungarian Standard, also includes a new examination method called the micro-Deval method for railway ballast aggregates, which was previously not used in Hungary. This paper presents the test results of aggregates for railway ballast-producing quarries, according to newly accepted Standard. The test materials consist of andesite, basalt, dolomite and limestone. The results cover a significant range. The study was aimed at finding a relation between the testing methods, in order to reduce the testing procedure; however, no clear relationship was found.

Restricted access

Abstract  

As a part of a project aimed at precise correlation of the Jurassic–Cretaceous (J/K) boundary interval in the Tethyan and Boreal realms, neutron and photon activation analyses were employed in geochemical characterization of limestone samples from the Brodno section, Slovakia, which offers a record of hemipelagic marine sediments around the J/K boundary in the Tethyan realm. Nickel and antimony anomalies exceeding almost twenty times the levels in neighboring beds were found near the beds assigned recently to the J/K boundary. Elucidation of their origin (volcanism, isochronous meteoritic impact, concentrating in, e.g., sulfides) requires further investigation.

Restricted access

Eperkés Hill is a thoroughly studied classic exposure, yet its facies interpretation is still debated. The issue is whether Upper Triassic - lowermost Jurassic carbonates are regular beds or blocks embedded within the Kimmeridgian-Berriasian limestone. The answer to this question is important for the interpretation of the structural evolution and paleogeography of the Transdanubian Range area at the Jurassic-Cretaceous boundary; we decided therefore to contribute to the solution by applying paleomagnetism to the problem.  We tested several regular beds and suspected olistoliths from two artificial exposures. In order to check the consistency of the paleomagnetic signal on site level, we drilled three or more cores from each, and subjected them to standard paleomagnetic laboratory processing and evaluation.  We found that magnetic parameters were distinctly different for "regular" beds and for suspected olistoliths, but that the paleomagnetic signal was consistent within every site. However, between-site consistency was extremely high for regular beds, but was non-existent for the "megabreccia" horizon. Thus, our results confirm that older limestone was moved and re-deposited during the Late Jurassic-Early Cretaceous, indicating geodynamic conditions similar to those in the Northern Calcareous Alps.

Restricted access

Historical storage cellars in Budapest

The architectural history and functional operation of an industrial building in 19th-century Hungary

Építés - Építészettudomány
Authors: Martin Pilsitz and Zsuzsanna Nádasi-Antal

The Kőbánya district of Budapest is situated on the eastern margins of the Hungarian capital city. Beneath Kőbánya there is an extensive limestone layer, in which tunnels and passages have been made, ‍some of which appear to date from the 13th century. In the 19th century, the limestone caverns of Budapest-Kőbánya were used for the refrigeration of perishable goods in large quantities. The caverns‍ represent one of Budapest’s historical industrial landmarks, although their architectural history has not been documented in full. This article analyses the architectural development of these evidently low-tech‍ facilities, while also exploring their significant role in the city’s urbanisation. The technical functions and structure of the system of caverns may be useful as a resource for society in the future when the supply‍ of fossil fuels runs out. The effectiveness of the caverns as places for refrigeration can be demonstrated through climatic calculations. The cavern system has significant energy capabilities, given that there is a‍constant air temperature throughout the year. The vast amount of geothermal energy could be used to cool heat pumps or heat exchangers. The results of measurements taken in preparation for this article are‍ presented.

Restricted access

Abstract

The massive red limestone of Tardos-Süttő popularly called red marble for its elegant looks both in the Middle Ages and today was revived as a representative building material (after the beginnings in the 12–13th centuries) by the lapidaries coming from Italy during King Matthias' reign. For the rebuilding of the Royal Palace in Buda in renaissance style, this material was used in large quantities for the moulded stone structures in addition to Buda marl (and to a far lesser extent freshwater limestone and rough stone). The 650 or so red marble carved fragments unearthed in Buda have been inventoried again in recent years within the Medium Regni program of the Széchenyi Plan. By examining each fragment in the lapidaria, we corrected and revised the manuscript formal-typological catalogue made by Emese Nagy in the 1990s. To introduce the work completed, we present a part of the catalogue and explicate a special question of reconstruction, the type of cross window with pilaster surrounds, shedding new light on certain assumptions maintained by the professional community.

Restricted access

The karstic bauxites of Mt. Grebnik, Kosovo, represent a unique deposit of the diasporic bauxites of Upper Cretaceous age in the former Yugoslavia. They are typically transitional between ferruginous bauxites and karstic Ni-Fe ores. Bauxites originated from surrounding Cretaceous weathering crusts on ultramafic rocks and on shale of the diabase-chert formation. Chemical and trace element analyses of the bauxite samples collected along a vertical profile of a typical deposit are presented and discussed. Trace element patterns, including REE and Ni, are typical for karstic bauxites formed in situ, during bauxitization of argillaceous material accumulated in a karstic depression. In connection with this, a progressive enrichment of the REE and Ni toward the bottom of the deposit is well pronounced, with formation of authigenic REE mineral, synchysite-(Nd), and Ni-bearing chlorite on the contact with the footwall limestone.

Restricted access

A new closed rock sward association ( Festuco rupicolae-Arrhenatheretum Erdős et Morschhauser, ass. nova.) has been found and described in the Villány Mts (SW Hungary). This community lives in northern expositions, near the ridge or the plateau. Bedrock is limestone and dolomite. In the association dominated by the grasses Festuca rupicola and Arrhenatherum elatius , an unusual mixing of species can be encountered: species of the mesophilous forests, of the karst shrub-forests and of the xerophilous grasslands and rock swards occur together in this community. Description of the new community as a distinct association is supported by the PCoA ordination and the differential species. Ecological properties of the community were characterised by using ecological indicator values. This analysis also shows the dual character of the association. We analysed the new association by computing the spectra of the social behaviour types. The extraordinarily great amount of the disturbance tolerants is probably a consequence of the former grazing pressure or some other disturbance.

Restricted access

Abstract  

The novel method of thermoluminescence (TL) dating of megalithic (cyclopean) limestone monuments and/or marble statues will be briefly reviewed. The problems and recent examples to be discussed include: (a) the determination of the accumulated archaeological dose, Dar, (b) the sample homogeneity, (c) the scattering in TL measurements, (d) the rate in solar bleaching of TL, and (e) dose-plateau inconsistencies. In retrospect, the solar bleaching of TL in some marbles refers to at least 30 mm depth, the scattering of TL measurements at best varies around ±10%, and the partial bleaching technique should be prudently applied for Dar determination. The extension of this method to date (by TL or OSL) for other rock types is discussed.

Restricted access

Abstract  

A convenient non-destructive method for the determination of low level210Pb and226Ra with an ordinary high-purity Ge-detector is presented. The ordinary Ge-detectors used in this work were available to measure 46.5 keV -rays of210Pb. These detectors were also useful for the non-destructive analysis of low-level226Ra in lime-stone and calcium chemicals when a stream of nitrogen gas was maintained around the detectors. By this method, measurements could be carried out not only for210Pb and226Ra but also for other -emitting radionuclides simultaneously, using the same detector. The detection limits of about 1 Bq per sample for210Pb and about 0.05 Bq per sample for226Ra, respectively, were estimated, when the samples were counted for 1–2 days.

Restricted access