the upper cretaceous carbonate sequence of ab-deraz formation is well exposed in the kopet- dagh basin. this formation comprises marly limestone and three chalky limestone units. chalky limestone of ab-deraz formation is mainly composed of calcareous dinoflagellate (pithonellid calcispher), cocolithofore and planktonic foraminifera. carbon and oxygen stable isotopes analysis of the third chalky...

The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexa...

Eine Eintopfsynthese eines CAAC-stabilisierten, unsymmetrischen, cyclischen Diborens wurde mittels Zweielektronenreduktion CAAC-Addukts von B2Br4(SMe2)2 entwickelt. Theoretische Studien offenbarten, dass dieses Diboren einen signifikant geringeren HOMO-LUMO-Abstand als bisher beschriebene NHC- und Phosphan-stabilisierte Diborene besitzt. Die Komplexierung des mit [AuCl(PCy3)] lieferte zwei Dibo...

Problem statement: When supervising a team of semi-autonomous robots, the operator’s task is not only the manipulation of each robot but also achievement of the top goal that is assigned to the entire team of humans and robots. The operators are demanded to comprehend highly complex states and make appropriate decisions in dynamic environment using the limited cognitive resources. The Ecologica...

The Ca, Mg, O, and C isotopic and trace elemental compositions of marine limestones and dolostones from ODP Site 1196A, which range in depth ( 58 to 627 mbsf) and in depositional age ( 5 and 23 Ma), are presented. The objectives of the study are to explore the potential for non-traditional isotope systems to fingerprint diagenesis, to quantify the extent to which geochemical proxies are altered...

An investigation is made into the effects of water jet pressure, nozzle diameter, traverse speed of the nozzle over the rock surface and the number of times the jet passes over the same area on the penetration of a water jet into Indiana limestone. The effectiveness of the cut is judged on the depth of cut established and the specific energy of rock removal. Pressure is varied in the range from...

Abstract Wadi Mawathil area is characterized by the existence of carbonates, represented “Egyptian Alabaster” (calcite alabaster) and “Bucchino” (recrystallized limestone). One most important geological heritage in Egypt Egyptian Alabaster quarries. The considered main economic resource study recrystallized limestone occasionally can be quarried. Field revealed that covered Middle Eocene rocks ...

The family Streptaxidae in Laos is revised. Twelve species are known, mainly from limestone areas, in the genera Discartemon Pfeiffer, 1856, Perrottetia Kobelt, 1905, Haploptychius Möllendorff, 1906, and Indoartemon Forcart, 1946. Three new species, Perrottetia unidentata sp. n. and Perrottetia megadentata sp. n. from northern and central Laos, and Indoartemon diodonta sp. n. from central Laos,...