Leonid Popov - Academia.edu (original) (raw)
Papers by Leonid Popov
The Cambrian Radiation of Brachiopods
Topics in geobiology, 1992
Tectonophysics, May 1, 2000
Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often expla... more Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often explained by rapid eustatic changes -so called 'third-order eustatic events'. Considerable influence of regional tectonics on relative sea-level changes has been demonstrated by many authors, but because of uncertainties in the timing of short events in widely separated regions, the problem of separating tectonic and eustatic factors still remains unsolved. In this paper, a new and simple approach is used to reveal the presence or absence of eustatic events. We consider the St. Petersburg area and North Estonia in the north-eastern region of the East Baltic. From the late Early Cambrian until the middle of the Tremadoc (early Ordovician), deposition was extremely slow and the sea bed remained for a long time in a well defined peritidal zone in a water depth ≤10 m. Under such environmental conditions, a sea-level rise of ≥10 m would result in marked changes in the character of faunas and sedimentation. In the time interval considered here, significant sea deepening in the north-eastern Baltic region occurred only twice, and its magnitude did not exceed 10-20 m. A fall of sea level by ≥10 m would result in complete regression in the peritidal zone. This situation also occurred in region. However, the preservation of a sequence of unconsolidated sands, which is only a few tens of metres thick and includes all the main stratigraphic subdivisions on a regional scale, indicates that the crustal surface reached a very low altitude ≤10-20 m above sea level. These data show that in the late Late Cambrian to the middle of the Tremadoc, over a period of ~40 m.y. long, eustatic sea-level changes did not exceed ±10-20 m. This limits the magnitude of several thirdorder cycles -eustatic events with duration of a few million years, which have been proposed previously for the epoch of the transition from the Cambrian to the Ordovician. In the late Early Cambrian to the Late Cambrian, transgressions and regressions with a magnitude of ~50-150 m took place in southern Sweden and Lithuania. Since these phenomena occurred when there were no comparable eustatic sea-level changes, they must be associated with regional tectonic movements. Some were rapid and could be easily misinterpreted as indications of third-order eustatic changes. It is probable that some of the other eustatic events that have been proposed for the Phanerozoic were actually not of eustatic but of tectonic origin. Such rapid tectonic movements with magnitude of ~50-100 m in cratonic areas can be caused by changes in the forces in the lithospheric layer with a laterally variable thickness, and by phase transitions in the mafic lower crust. Depending on the spatial distribution of vertical crustal movements, both these mechanisms could have been operating in the East Baltic and southern Sweden in the Cambrian.
Alcheringa, Dec 1, 2013
The Silurian (Aeronian) post-extinction recovery brachiopod fauna of Iran and Afghanistan is char... more The Silurian (Aeronian) post-extinction recovery brachiopod fauna of Iran and Afghanistan is characterized by a proliferation of the Stegocornu Brachiopod Association, which includes prominent endemic rhynchonellide and spiriferide components. A local variety of that association, recently recovered from the Shabdjereh Formation of Kerman Province, East-Central Iran, contains eight brachiopod species, including the rhynchonellide Kermanirhyncha granulata gen. et sp. nov., and the spiriferides Levanispirifer alatus gen. et sp. nov. and Mictospirifer obtusus sp. nov. A new phylogenetic analysis of the earliest Late Ordovician to Aeronian spiriferides, within the general context of the Ordovician radiation of rhynchonelliform brachiopods with calcified brachial supports, reveals the following two major centres of biodiversification and dispersal: (1) the Laurentian palaeocontinent, which is the likely place of origin and initial diversification of the atrypide suborders Lissatrypidina and Anazygidina; and (2) the assemblage of Kazakh island arcs and microplates (known also as Kazakh Archipelago), which was the centre of origin and initial dispersal of the atrypid suborder Atrypidina and the order Spiriferida. South China represents a major refuge, where spiriferides survived the terminal Ordovician extinction and from where they dispersed towards adjacent parts of Gondwana including the Iranian terranes. The latter areas were an important secondary centre of spiriferide biodiversification during the Aeronian Age.
Acta Geologica Polonica, 2017
Detailed biogeographical and biofacies analyses of the Late Ordovician brachiopod faunas with 160... more Detailed biogeographical and biofacies analyses of the Late Ordovician brachiopod faunas with 160 genera, grouped into 94 faunas from individual lithotectonic units within the Kazakh Orogen strongly support an archipelago model for that time in that area. The Kazakh island arcs and microcontinents within several separate clusters were located in the tropics on both sides of the Equator. Key units, from which the Late Ordovician faunas are now well known, include the Boshchekul, Chingiz-Tarbagatai, and Chu-Ili terranes. The development of brachiopod biogeography within the nearly ten million year time span of the Late Ordovician from about 458 to 443 Ma (Sandbian, Katian, and Hirnantian), is supported by much new data, including our revised identifications from the Kazakh Orogen and elsewhere. The Kazakh archipelago was west of the Australasian segment of the Gondwana Supercontinent, and relatively near the Tarim, South China and North China continents, apart from the Atashu-Zhamshi ...
Late Cambrian relative age constraints by acritarchs on the post-Timanian deposition on Kolguev Island, Arctic Russia
Geological Society, London, Memoirs, 2004
On the origin of sea-level changes in the Baltic paleobasin in the Cambrian and Early Ordovician
The nature of transgressions and regressions in the Baltic Paleobasin in the Cambrian and earliest Ordovician
Early Cambrian Brachiopods from South Kirgiziya
The Cambrian Radiation of Brachiopods
Topics in Geobiology, 1992
Tectonophysics, 2000
Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often expla... more Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often explained by rapid eustatic changes -so called 'third-order eustatic events'. Considerable influence of regional tectonics on relative sea-level changes has been demonstrated by many authors, but because of uncertainties in the timing of short events in widely separated regions, the problem of separating tectonic and eustatic factors still remains unsolved. In this paper, a new and simple approach is used to reveal the presence or absence of eustatic events. We consider the St. Petersburg area and North Estonia in the north-eastern region of the East Baltic. From the late Early Cambrian until the middle of the Tremadoc (early Ordovician), deposition was extremely slow and the sea bed remained for a long time in a well defined peritidal zone in a water depth ≤10 m. Under such environmental conditions, a sea-level rise of ≥10 m would result in marked changes in the character of faunas and sedimentation. In the time interval considered here, significant sea deepening in the north-eastern Baltic region occurred only twice, and its magnitude did not exceed 10-20 m. A fall of sea level by ≥10 m would result in complete regression in the peritidal zone. This situation also occurred in region. However, the preservation of a sequence of unconsolidated sands, which is only a few tens of metres thick and includes all the main stratigraphic subdivisions on a regional scale, indicates that the crustal surface reached a very low altitude ≤10-20 m above sea level. These data show that in the late Late Cambrian to the middle of the Tremadoc, over a period of ~40 m.y. long, eustatic sea-level changes did not exceed ±10-20 m. This limits the magnitude of several thirdorder cycles -eustatic events with duration of a few million years, which have been proposed previously for the epoch of the transition from the Cambrian to the Ordovician. In the late Early Cambrian to the Late Cambrian, transgressions and regressions with a magnitude of ~50-150 m took place in southern Sweden and Lithuania. Since these phenomena occurred when there were no comparable eustatic sea-level changes, they must be associated with regional tectonic movements. Some were rapid and could be easily misinterpreted as indications of third-order eustatic changes. It is probable that some of the other eustatic events that have been proposed for the Phanerozoic were actually not of eustatic but of tectonic origin. Such rapid tectonic movements with magnitude of ~50-100 m in cratonic areas can be caused by changes in the forces in the lithospheric layer with a laterally variable thickness, and by phase transitions in the mafic lower crust. Depending on the spatial distribution of vertical crustal movements, both these mechanisms could have been operating in the East Baltic and southern Sweden in the Cambrian.
The radiation of early Silurian spiriferide brachiopods, with new taxa from the Llandovery of Iran
Alcheringa: An Australasian Journal of Palaeontology, 2013
Late Ordovician linguliformean microbrachiopods from north-central Kazakhstan
Alcheringa: An Australasian Journal of Palaeontology, 2000
Geobios, 2000
A moderately diverse linguliformean microbrachiopod assemblage from the upper Bestyube Formation ... more A moderately diverse linguliformean microbrachiopod assemblage from the upper Bestyube Formation (Ordovician, lower Ashgill) contains 12 taxa including one new genus Tasbulakia (with T tenuis nov. sp. as a type species) and three new species Biernatia prominens, Scaphelasma zharykensis and Veliseptum pulchrum. The fauna includes the first record of the occurrence of Nushbiella, Cyrtonotreta, Ephippelasma and Veliseptum in the Ashgill. The co-occurrence of the this assemblage with the Ovalocephalus trilobite fauna suggests deep water biofacies of Benthic Assemblage 4 or 5. The acrotretide component of the assemblage demonstrates greatest similarity with late Ordovician (Llandeilo to early Ashgill) linguliformean brachiopod faunas of Baltoscandia.
Concept design of the megawatt power level gyrotron stabilized by a low-power signal for DEMO project
Nuclear Fusion, 2022
The specific features of the main components of the new powerful 230 GHz/80 kV/40 A gyrotron aime... more The specific features of the main components of the new powerful 230 GHz/80 kV/40 A gyrotron aimed to use in the future control fusion facility DEMO are described. The gyrotron design provides a stable output power generation of more than 1 MW using a superconducting magnet with a moderate size warm bore. Furthermore, the new original quasi-optical converter providing the gyrotron operation in three possible regimes—two free oscillation regimes with co-rotating TE33,13 or counter-rotating TE33,−13 mode, and the regime with frequency locking by the stable input signal—is suggested and optimized. The Gaussian content in the output wave-beam in all above-mentioned regimes is about 98%.
Plasma Physics and Controlled Fusion, 2019
The electron cyclotron resonance heating (ECRH) system of the ASDEX Upgrade tokomak has been upgr... more The electron cyclotron resonance heating (ECRH) system of the ASDEX Upgrade tokomak has been upgraded over the last 15 years from a 2 MW, 2 s, 140 GHz system to an 8 MW, 10 s, dual frequency system (105/140 GHz). The power exceeds the L/H power threshold by at least a factor of two, even for high densities, and roughly equals the installed ion cyclotron range of frequencies power. The power of both wave heating systems together (>10 MW in the plasma) is about half of the available neutral beam injection (NBI) power, allowing significant variations of torque input, of the shape of the heating profile and of Qe/Qi, even at high heating power. For applications at a low magnetic field an X3-heating scheme is routinely in use. Such a scenario is now also forseen for ITER to study the first H-modes at one third of the full field. This versatile system allows one to address important issues fundamental to a fusion reactor: H-mode operation with dominant electron heating, accessing low c...
Plasma Devices and Operations, 1998
The paper presents the approach and results of development of the 170 GHz/1 MW ITER gyrotron in R... more The paper presents the approach and results of development of the 170 GHz/1 MW ITER gyrotron in Russia. The main problems of elaborating powerful gyrotrons are discussed. Results of 170 GHz gyrotron tests are analyzed and compared with the theory. ITER related 110 GHz and 140 GHz gyrotrons are also investigated. The possibility to create a 170 GHz/1 MW gyrotron for ITER is proved by calculations and experiments.
Fusion Science and Technology, 2007
First occurrence of the genus Bicarinatina (Brachiopoda, Inarticulata) from the Middle Devonian in North America (Alaska)
Journal of Paleontology, 1994
The lingulid brachiopod species Bicarinatina kongakutensis n. sp. is recorded here from the Middl... more The lingulid brachiopod species Bicarinatina kongakutensis n. sp. is recorded here from the Middle Devonian (Eifelian) Ulungarat unit in Arctic Alaska. A restudy of the type species, Bicarinatina bicarinata (Kutorga) from the Middle Devonian (Eifelian) of Eastern Europe, suggests close affinities to the Ordovician genus Pseudolingula and gives good reason to assign Bicarinatina to the family Pseudolingulidae. There are no important points of difference in the morphologies of Bicarinatina and the Early Carboniferous lingulid genus Liralingua and, thus, both genera have been synonymized.
Development of 170 GHz/ 1MW/ 50%/ CW gyrotron for ITER
Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.
Recent test results of 170 GHz/1 MW/CW gyrotron being developed in Russia within the ITER program... more Recent test results of 170 GHz/1 MW/CW gyrotron being developed in Russia within the ITER program are presented. At pulse duration of 0.1 s, power of 1.15 MW in the output Gaussian beam was attained. In the experiments on pulse extension, output power was not so large considering performance capabilities of high voltage source. At output power of 0.85-0.9 MW,
International Journal of Infrared and Millimeter Waves, 2007
%&# ' ( ) '* * + , * -) * . ) ,* / ( ) * 0 * 1 ( * ) , -* * *( " %23!4 0 * '* / ( ) * 0 * * ( ) "... more %&# ' ( ) '* * + , * -) * . ) ,* / ( ) * 0 * 1 ( * ) , -* * *( " %23!4 0 * '* / ( ) * 0 * * ( ) " %23!4 0 * '* ( ) 5 * 6 7 ) " %3$28 7 ) '* * *,
The Cambrian Radiation of Brachiopods
Topics in geobiology, 1992
Tectonophysics, May 1, 2000
Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often expla... more Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often explained by rapid eustatic changes -so called 'third-order eustatic events'. Considerable influence of regional tectonics on relative sea-level changes has been demonstrated by many authors, but because of uncertainties in the timing of short events in widely separated regions, the problem of separating tectonic and eustatic factors still remains unsolved. In this paper, a new and simple approach is used to reveal the presence or absence of eustatic events. We consider the St. Petersburg area and North Estonia in the north-eastern region of the East Baltic. From the late Early Cambrian until the middle of the Tremadoc (early Ordovician), deposition was extremely slow and the sea bed remained for a long time in a well defined peritidal zone in a water depth ≤10 m. Under such environmental conditions, a sea-level rise of ≥10 m would result in marked changes in the character of faunas and sedimentation. In the time interval considered here, significant sea deepening in the north-eastern Baltic region occurred only twice, and its magnitude did not exceed 10-20 m. A fall of sea level by ≥10 m would result in complete regression in the peritidal zone. This situation also occurred in region. However, the preservation of a sequence of unconsolidated sands, which is only a few tens of metres thick and includes all the main stratigraphic subdivisions on a regional scale, indicates that the crustal surface reached a very low altitude ≤10-20 m above sea level. These data show that in the late Late Cambrian to the middle of the Tremadoc, over a period of ~40 m.y. long, eustatic sea-level changes did not exceed ±10-20 m. This limits the magnitude of several thirdorder cycles -eustatic events with duration of a few million years, which have been proposed previously for the epoch of the transition from the Cambrian to the Ordovician. In the late Early Cambrian to the Late Cambrian, transgressions and regressions with a magnitude of ~50-150 m took place in southern Sweden and Lithuania. Since these phenomena occurred when there were no comparable eustatic sea-level changes, they must be associated with regional tectonic movements. Some were rapid and could be easily misinterpreted as indications of third-order eustatic changes. It is probable that some of the other eustatic events that have been proposed for the Phanerozoic were actually not of eustatic but of tectonic origin. Such rapid tectonic movements with magnitude of ~50-100 m in cratonic areas can be caused by changes in the forces in the lithospheric layer with a laterally variable thickness, and by phase transitions in the mafic lower crust. Depending on the spatial distribution of vertical crustal movements, both these mechanisms could have been operating in the East Baltic and southern Sweden in the Cambrian.
Alcheringa, Dec 1, 2013
The Silurian (Aeronian) post-extinction recovery brachiopod fauna of Iran and Afghanistan is char... more The Silurian (Aeronian) post-extinction recovery brachiopod fauna of Iran and Afghanistan is characterized by a proliferation of the Stegocornu Brachiopod Association, which includes prominent endemic rhynchonellide and spiriferide components. A local variety of that association, recently recovered from the Shabdjereh Formation of Kerman Province, East-Central Iran, contains eight brachiopod species, including the rhynchonellide Kermanirhyncha granulata gen. et sp. nov., and the spiriferides Levanispirifer alatus gen. et sp. nov. and Mictospirifer obtusus sp. nov. A new phylogenetic analysis of the earliest Late Ordovician to Aeronian spiriferides, within the general context of the Ordovician radiation of rhynchonelliform brachiopods with calcified brachial supports, reveals the following two major centres of biodiversification and dispersal: (1) the Laurentian palaeocontinent, which is the likely place of origin and initial diversification of the atrypide suborders Lissatrypidina and Anazygidina; and (2) the assemblage of Kazakh island arcs and microplates (known also as Kazakh Archipelago), which was the centre of origin and initial dispersal of the atrypid suborder Atrypidina and the order Spiriferida. South China represents a major refuge, where spiriferides survived the terminal Ordovician extinction and from where they dispersed towards adjacent parts of Gondwana including the Iranian terranes. The latter areas were an important secondary centre of spiriferide biodiversification during the Aeronian Age.
Acta Geologica Polonica, 2017
Detailed biogeographical and biofacies analyses of the Late Ordovician brachiopod faunas with 160... more Detailed biogeographical and biofacies analyses of the Late Ordovician brachiopod faunas with 160 genera, grouped into 94 faunas from individual lithotectonic units within the Kazakh Orogen strongly support an archipelago model for that time in that area. The Kazakh island arcs and microcontinents within several separate clusters were located in the tropics on both sides of the Equator. Key units, from which the Late Ordovician faunas are now well known, include the Boshchekul, Chingiz-Tarbagatai, and Chu-Ili terranes. The development of brachiopod biogeography within the nearly ten million year time span of the Late Ordovician from about 458 to 443 Ma (Sandbian, Katian, and Hirnantian), is supported by much new data, including our revised identifications from the Kazakh Orogen and elsewhere. The Kazakh archipelago was west of the Australasian segment of the Gondwana Supercontinent, and relatively near the Tarim, South China and North China continents, apart from the Atashu-Zhamshi ...
Late Cambrian relative age constraints by acritarchs on the post-Timanian deposition on Kolguev Island, Arctic Russia
Geological Society, London, Memoirs, 2004
On the origin of sea-level changes in the Baltic paleobasin in the Cambrian and Early Ordovician
The nature of transgressions and regressions in the Baltic Paleobasin in the Cambrian and earliest Ordovician
Early Cambrian Brachiopods from South Kirgiziya
The Cambrian Radiation of Brachiopods
Topics in Geobiology, 1992
Tectonophysics, 2000
Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often expla... more Fluctuations in sea depth within a magnitude 20-100 m and a duration of 1-10 m.y. are often explained by rapid eustatic changes -so called 'third-order eustatic events'. Considerable influence of regional tectonics on relative sea-level changes has been demonstrated by many authors, but because of uncertainties in the timing of short events in widely separated regions, the problem of separating tectonic and eustatic factors still remains unsolved. In this paper, a new and simple approach is used to reveal the presence or absence of eustatic events. We consider the St. Petersburg area and North Estonia in the north-eastern region of the East Baltic. From the late Early Cambrian until the middle of the Tremadoc (early Ordovician), deposition was extremely slow and the sea bed remained for a long time in a well defined peritidal zone in a water depth ≤10 m. Under such environmental conditions, a sea-level rise of ≥10 m would result in marked changes in the character of faunas and sedimentation. In the time interval considered here, significant sea deepening in the north-eastern Baltic region occurred only twice, and its magnitude did not exceed 10-20 m. A fall of sea level by ≥10 m would result in complete regression in the peritidal zone. This situation also occurred in region. However, the preservation of a sequence of unconsolidated sands, which is only a few tens of metres thick and includes all the main stratigraphic subdivisions on a regional scale, indicates that the crustal surface reached a very low altitude ≤10-20 m above sea level. These data show that in the late Late Cambrian to the middle of the Tremadoc, over a period of ~40 m.y. long, eustatic sea-level changes did not exceed ±10-20 m. This limits the magnitude of several thirdorder cycles -eustatic events with duration of a few million years, which have been proposed previously for the epoch of the transition from the Cambrian to the Ordovician. In the late Early Cambrian to the Late Cambrian, transgressions and regressions with a magnitude of ~50-150 m took place in southern Sweden and Lithuania. Since these phenomena occurred when there were no comparable eustatic sea-level changes, they must be associated with regional tectonic movements. Some were rapid and could be easily misinterpreted as indications of third-order eustatic changes. It is probable that some of the other eustatic events that have been proposed for the Phanerozoic were actually not of eustatic but of tectonic origin. Such rapid tectonic movements with magnitude of ~50-100 m in cratonic areas can be caused by changes in the forces in the lithospheric layer with a laterally variable thickness, and by phase transitions in the mafic lower crust. Depending on the spatial distribution of vertical crustal movements, both these mechanisms could have been operating in the East Baltic and southern Sweden in the Cambrian.
The radiation of early Silurian spiriferide brachiopods, with new taxa from the Llandovery of Iran
Alcheringa: An Australasian Journal of Palaeontology, 2013
Late Ordovician linguliformean microbrachiopods from north-central Kazakhstan
Alcheringa: An Australasian Journal of Palaeontology, 2000
Geobios, 2000
A moderately diverse linguliformean microbrachiopod assemblage from the upper Bestyube Formation ... more A moderately diverse linguliformean microbrachiopod assemblage from the upper Bestyube Formation (Ordovician, lower Ashgill) contains 12 taxa including one new genus Tasbulakia (with T tenuis nov. sp. as a type species) and three new species Biernatia prominens, Scaphelasma zharykensis and Veliseptum pulchrum. The fauna includes the first record of the occurrence of Nushbiella, Cyrtonotreta, Ephippelasma and Veliseptum in the Ashgill. The co-occurrence of the this assemblage with the Ovalocephalus trilobite fauna suggests deep water biofacies of Benthic Assemblage 4 or 5. The acrotretide component of the assemblage demonstrates greatest similarity with late Ordovician (Llandeilo to early Ashgill) linguliformean brachiopod faunas of Baltoscandia.
Concept design of the megawatt power level gyrotron stabilized by a low-power signal for DEMO project
Nuclear Fusion, 2022
The specific features of the main components of the new powerful 230 GHz/80 kV/40 A gyrotron aime... more The specific features of the main components of the new powerful 230 GHz/80 kV/40 A gyrotron aimed to use in the future control fusion facility DEMO are described. The gyrotron design provides a stable output power generation of more than 1 MW using a superconducting magnet with a moderate size warm bore. Furthermore, the new original quasi-optical converter providing the gyrotron operation in three possible regimes—two free oscillation regimes with co-rotating TE33,13 or counter-rotating TE33,−13 mode, and the regime with frequency locking by the stable input signal—is suggested and optimized. The Gaussian content in the output wave-beam in all above-mentioned regimes is about 98%.
Plasma Physics and Controlled Fusion, 2019
The electron cyclotron resonance heating (ECRH) system of the ASDEX Upgrade tokomak has been upgr... more The electron cyclotron resonance heating (ECRH) system of the ASDEX Upgrade tokomak has been upgraded over the last 15 years from a 2 MW, 2 s, 140 GHz system to an 8 MW, 10 s, dual frequency system (105/140 GHz). The power exceeds the L/H power threshold by at least a factor of two, even for high densities, and roughly equals the installed ion cyclotron range of frequencies power. The power of both wave heating systems together (>10 MW in the plasma) is about half of the available neutral beam injection (NBI) power, allowing significant variations of torque input, of the shape of the heating profile and of Qe/Qi, even at high heating power. For applications at a low magnetic field an X3-heating scheme is routinely in use. Such a scenario is now also forseen for ITER to study the first H-modes at one third of the full field. This versatile system allows one to address important issues fundamental to a fusion reactor: H-mode operation with dominant electron heating, accessing low c...
Plasma Devices and Operations, 1998
The paper presents the approach and results of development of the 170 GHz/1 MW ITER gyrotron in R... more The paper presents the approach and results of development of the 170 GHz/1 MW ITER gyrotron in Russia. The main problems of elaborating powerful gyrotrons are discussed. Results of 170 GHz gyrotron tests are analyzed and compared with the theory. ITER related 110 GHz and 140 GHz gyrotrons are also investigated. The possibility to create a 170 GHz/1 MW gyrotron for ITER is proved by calculations and experiments.
Fusion Science and Technology, 2007
First occurrence of the genus Bicarinatina (Brachiopoda, Inarticulata) from the Middle Devonian in North America (Alaska)
Journal of Paleontology, 1994
The lingulid brachiopod species Bicarinatina kongakutensis n. sp. is recorded here from the Middl... more The lingulid brachiopod species Bicarinatina kongakutensis n. sp. is recorded here from the Middle Devonian (Eifelian) Ulungarat unit in Arctic Alaska. A restudy of the type species, Bicarinatina bicarinata (Kutorga) from the Middle Devonian (Eifelian) of Eastern Europe, suggests close affinities to the Ordovician genus Pseudolingula and gives good reason to assign Bicarinatina to the family Pseudolingulidae. There are no important points of difference in the morphologies of Bicarinatina and the Early Carboniferous lingulid genus Liralingua and, thus, both genera have been synonymized.
Development of 170 GHz/ 1MW/ 50%/ CW gyrotron for ITER
Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference on 2004 and 12th International Conference on Terahertz Electronics, 2004.
Recent test results of 170 GHz/1 MW/CW gyrotron being developed in Russia within the ITER program... more Recent test results of 170 GHz/1 MW/CW gyrotron being developed in Russia within the ITER program are presented. At pulse duration of 0.1 s, power of 1.15 MW in the output Gaussian beam was attained. In the experiments on pulse extension, output power was not so large considering performance capabilities of high voltage source. At output power of 0.85-0.9 MW,
International Journal of Infrared and Millimeter Waves, 2007
%&# ' ( ) '* * + , * -) * . ) ,* / ( ) * 0 * 1 ( * ) , -* * *( " %23!4 0 * '* / ( ) * 0 * * ( ) "... more %&# ' ( ) '* * + , * -) * . ) ,* / ( ) * 0 * 1 ( * ) , -* * *( " %23!4 0 * '* / ( ) * 0 * * ( ) " %23!4 0 * '* ( ) 5 * 6 7 ) " %3$28 7 ) '* * *,