Wyniki wyszukiwania - BazTech

1

The oldest seafloor massive sulfide deposits at the Mid - Atlantic Ridge: 230th/u chronology and composition

Kuznetsov V., Tabuns E., Kuksa K., Cherkashov G., Maksimov F., Bel’Tenev V., Lazareva L., Zherebtsov I., Grigoriev V., Baranova N.

Geochronometria

|

2015

|

Vol. 42, no.1

100--106

EN

A geochronological and geochemical study on 10 samples of seafloor massive sulfides (SMS) from the inactive Peterburgskoye hydrothermal field at the Mid-Atlantic Ridge (MAR) was carried out. The 230Th/U ages of the SMS are the oldest for the Quaternary hydrothermal ores ever found at the ocean floor. According to them the hydrothermal activity at Peterburgskoye field started at least 170 ka and continued down to 63 ka. The oldest hydrothermal ores from this field consist mainly of pyrite and chalcopyrite and have geochemical properties typical for SMS associated with basalts.

2

Comparative 230Th/U and 14C Dating of a Buried Stump Layer (Western Siberia)

Maksimov F., Kuznetsov V., Laukhin V., Kuksa K., Levchenko S., Grigoriev V.

Geochronometria

|

2015

|

Vol. 42, no.1

139--147

EN

Dating of late Pleistocene sediments remains a challenge in Quaternary chronology, due to the inherent limitations of the 14C and OSL methods. The 230Th/U radioisotope method is theoretically applicable to wood remnants contained within Pleistocene sediments, but few results have been published to date and in some cases, the age data are ambiguous. This paper tests the use of 230Th/U dating of fossil wood remnants dated earlier by radiocarbon method. We analyzed a buried larch trunk from a well-known stump layer in the Lipovka outcrop, located on the Tobol River bank in Western Siberia. The stump layer is preserved in situ. We determined the specific activities of U and Th isotopes in samples of both modern pine and fossil larch and proposed a model for the incorporation and distribution of U and Th in the buried wood during aging. Complications related with the recognition of geochemical closed systems with respect to U did not allow obtaining completely reliable 230Th/U age. Despite this the 230Th/U age obtained for the uppermost heartwood sample and 14C ages of the same larch trunk and other wood and vegetation remnants gave consistent results. These age data in combination with previously obtained pollen data testify the stump layer formation during the late cooling stage of the Karganian time (MIS-3, Middle Valdai).

3

The Principle of Formation of Smart Database of Safety Electronic Devices

Grigoriev V., Panchak R.

Machine Dynamics Problems

|

2007

|

Vol. 31, No. 3

32-37

EN

Database, which serves for search electronic safety and signaling devices, is considered at the paper. The main features of the database are accurate and fuzzy approaches. Safety and signalling electronic devices are well-known equipment on market. These devices can be distinguished by application, operational principles, technical parameters, dimensions, mass, price etc. For potential customer the main question is how to select correct devices for customer use. This problem can not be solved using existent catalogues, price-lists, Internet-sources etc. Therefore we decided to create new smart database which assists customer to make his choice selecting safety and signaling electronic devices. To achieve this target we proposed: - develop the database structure, select database management system (DMS) and required development software, - determine the conception for implementation of smart database of electronic safety and signalling devices, - develop database interface. Accurate approach provides that the customer knows parameters of required device. At implementation of fuzzy approach the search and parameters' specification are performed in interaction between customer and database. Interaction between customer enquiries and database is realized using Web-interface. Database interface is divided into two parts: interface for information search and interface for database management. For implementation of smart database we selected the following tools: database management system MySQL, PHP language which allows processing Web-applications and interaction enquiries, virtual Apache-server which is used for interaction between PHP and MySQL, operation system MS Windows XP. We designed operational model of smart database of infrared motion transducers and it shows good results.