On the Carboniferous shark Tristychius arcuatus Agassiz from Scotland

1978 ◽  
Vol 70 (4) ◽  
pp. 63-108 ◽  
Author(s):  
John R. F. Dick
Keyword(s):  
Oil Shale ◽  
Sensu Stricto ◽  
Skeletal Remains ◽  
Unusual Feature ◽  
Pectoral Fins

SynopsisSkeletal remains of Tristychius arcuatus commonly occur in ironstone nodules from the Scottish Upper and Lower Oil Shale Groups. This material is clearly distinguishable from the small shark from Glencartholm described by Traquair, Woodward and Moy-Thomas under this name. Study of the latter shows that its finspines are distinctly different from the holotype of T. arcuatus and, therefore, it has been renamed.Tristychius arcuatus sensu stricto is a medium-sized hybodont shark with a short gape, a functionally heterocercal tail and narrow-based, tribasal pectoral fins. Its most unusual feature is a well developed opercular gill cover composed of long hyoid rays. Evidence suggests that this character was present in several Palaeozoic sharks, although it is absent in all Recent elasmobranchs. It is not clear whether it was primitively present in chondrichthyans or evolved separately in several lineages.Hybodonts and ctenacanths are recognised as separate, specialised shark radiations, neither of which can be directly ancestral to Recent sharks. Of the two, hybodonts appear to be more closely related to Recent forms, although the presence of typical hybodont finspines in Tristychius arcuatus indicates that they had diverged from ancestral euselachians before the beginning of the Carboniferous.

Diplodoselache woodigen. et sp. nov., an early Carboniferous shark from the Midland Valley of Scotland

1981 ◽  
Vol 72 (2) ◽  
pp. 99-113 ◽  
Author(s):  
John R. F. Dick
Keyword(s):  
Surface Waters ◽  
Distinctive Feature ◽  
Oil Shale ◽  
Early Carboniferous ◽  
Dorsal Spine ◽  
Freshwater Environment ◽  
Lower Carboniferous ◽  
Pectoral Fins ◽  
Dorsal Fin ◽  
Late Palaeozoic

ABSTRACTA new fossil elasmobranch from the Lower Carboniferous Oil Shale groups (Viséan) of the Edinburgh area shows a mosaic of characters typical of at least two groups of early sharks. Its most distinctive feature is the small bicuspid teeth of “Diplodus” type. This, together with the long dorsal fin and the structure of the single, shallowly inserted dorsal spine, form a suite of characters previously considered unique to late Palaeozoic xenacanth sharks. Other features, such as the large equilobate tail and the structure of the pectoral fins, may have been retained from an ancestor of a more typical Palaeozoic elasmobranch appearance found in anacanthous and ctenacanth sharks. It is suggested that the xenacanths evolved from an ancestor within the anacanth-ctenacanth assemblage early in Carboniferous times and became adapted to a freshwater environment. This ancestor probably possessed a complex dermal skeleton including growing scales with both thickened and thin concave bases.The fauna of the fish-bearing nodules amongst which this shark has been found is interpretedas being lagoonal in origin. The shark was probably a medium sized (c.0·75–2·0 m lng)predator inhabiting the surface waters of the lagoon.

KREATYWNOŚĆ JAKO IMPERATYW I ATRYBUT WSPÓŁCZESNEGO PRZEDSIĘBIORSTWA

2018 ◽  
pp. 41-47
Author(s):  
Cezary Suszyński
Keyword(s):  
Sensu Stricto

Artykuł jest teoretycznym studium wspartym odniesieniami do praktyki zarządzania, którego celem jest przedstawienie argumentacji na rzecz tezy o kreatywności organizacyjnej jako imperatywie i zarazem atrybucie współczesnego przedsiębiorstwa (sensu largo). Obszarem studiów są wybrane teorie ekonomiczne (klasyczna, neoklasyczna, schumpeterowska, instytucjonalna) oraz niektóre koncepcje na gruncie zarządzania strategicznego (strategia jako: wzorzec, zestaw kluczowych kompetencji, zasobów i umiejętności przedsiębiorstwa, przełomowe innowacje, współkreowanie wartości). Analiza uwzględniająca obie perspektywy ujawnia immanentny charakter kreatywności organizacyjnej w procesach wzrostu i rozwoju przedsiębiorstw, zwłaszcza od fazy wykształcenia się zarządzania strategicznego. Wyraźnie rosnąca dynamika zmian (turbulencji) otoczenia przedsiębiorstw skłania je do sięgania po nowe rozwiązania w zakresie idei, koncepcji, zasobów, strategii, modeli biznesu, nadając organizacyjnej kreatywności charakter atrybutu współczesnego przedsiębiorstwa. Dodatkowy wniosek w świetle poczynionych konstatacji co do atrybutowego charakteru kreatywności organizacyjnej wskazuje również jako dyskusyjne spotykane w literaturze przedmiotu określenie "przedsiębiorstwo kreatywne", stosowane w odniesieniu do grupy przedsiębiorstw (sensu stricto) reprezentujących sektory (branże, przemysły) kreatywne. (

Brahmi legends on Umayyad Fulus: Interrogating local minting practices and numismatic transculturation in Gandhara (ca. 750 CE)

Afghanistan ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 153-165
Author(s):  
Waleed Ziad
Keyword(s):  
Base Metal ◽  
Late Antiquity ◽  
Eighth Century ◽  
Political Authority ◽  
Unusual Feature ◽  
Complex Relationship ◽  
Contact Zones ◽  
Confessional Identity ◽  
Derivatives Of

This paper concerns a historically significant find of copper derivatives of Umayyad post-reform fulus from Gandhara, probably minted in the mid-eighth century under Turk Shahi sovereignty (c. 667–875). The coins share an unusual feature: two Brahmi aksharas on an Umayyad AE prototype, inversely oriented to a partially-corrupted Arabic legend. These base metal coins represent perhaps the only known caliphal imitative varieties issued by moneyers beyond the eastern limits of Umayyad and Abbasid sovereignty. They have the potential to inform our understanding of the complex relationship between political authority, confessional identity, and coin typology in late antiquity – particularly within early “Hindu”– “Muslim” contact zones. Moreover, they provide invaluable clues into the circulatory regimes of Umayyad coinage.

Operation of an advanced 1/2 ton per day oil shale retort

1994 ◽  
Author(s):  
John Stehn ◽  
Scott Carter ◽  
Asmund Vego
Keyword(s):  
Oil Shale

Spectro-mechanical Characterization of Aromaticity and Maturity of Kerogens in Oil Shale at 6 nm Spatial Resolution

2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu
Keyword(s):  
Spatial Resolution ◽  
Oil Shale ◽  
Infrared Imaging ◽  
Mechanical Characterization ◽  
Optical Diffraction ◽  
Chemical Compositions ◽  
Valuable Insight ◽  
Eagle Ford Shale

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>

Suitability of forms of preparing seeds of Dalbergia miscolobium Benth for exposure to the tetrazolium test / Adequação das formas de preparação de sementes de Dalbergia miscolobium Benth para exposição ao teste de tetrazolium

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Juliana Martins de Mesquita Matos ◽  
Rosana De Carvalho Cristo Martins ◽  
Valéria Regina Bellotto ◽  
Lilian Gomes da Silva Rocha ◽  
Eloiza Aparecida Barbosa ◽  
...  
Keyword(s):  
Endangered Species ◽  
Filter Paper ◽  
Federal District ◽  
Complete Removal ◽  
Sensu Stricto ◽  
The Other ◽  
Distrito Federal ◽  
Viable Seeds ◽  
Range Test ◽  
Tetrazolium Test

Dalbergia miscolobium or Jacarandá do Cerrado is a species of legume in the Fabaceae family. It occurs in the sensu stricto Cerrado and in the dystrophic cerradão. It shows potential for landscaping and for recovering damaged areas. It is an endangered species and therefore is protected by the law that prevents cut in areas of the Federal District (Decree No. 14.783/93). The purpose of this study was to determine the best procedure to prepare seeds of Dalbergia miscolobium to assess viability in the tetrazolium test. We carried out the following treatments: i) hydration on filter paper at 25 ° C, ii) hydration on filter paper at 25 ° C followed by a cut in the tegument and iii) hydration on filter paper at 25 ° C followed bya complete removal of the tegument. The results were analyzed using analysis of variance and the Tukey range test. The analyzes showed that the best procedure to prepare seeds of Dalbergia miscolobium is the treatment in which there is a hydration followed by the complete removal of the integument. Where 78% of the seeds showed uniform staining, indicating that the seeds analyzed are of good quality. The other treatments, hydration and hydration followed by cutting, showed respectively 35% and 41% of viable seeds. RESUMO A Dalbergia miscolobium ou Jacarandá do Cerrado é uma espécie de leguminosa da família Fabaceae. Ocorre no sentido stricto Cerrado e no cerradão distrófico. Possui potencial para paisagismo e para recuperar áreas degradadas. É uma espécie ameaçada de extinção e, portanto, está protegida pela lei que previne o corte em áreas do Distrito Federal (Decreto 14.783 / 93). O objetivo deste estudo foi determinar o melhor procedimento de prepararação das sementes de Dalbergia miscolobium para serem submetidas à análise de viabilidade pelo teste de tetrazólio. Foram realizados os seguintes tratamentos: i) hidratação em papel de filtro a 25 ° C, ii) hidratação em papel de filtro a 25 ° C seguida de um corte no tegumento e iii) hidratação em papel de filtro a 25 ° C seguido de remoção completa do tegumento. Os resultados foram analisados utilizando-se a análise de variância e o teste de médias de Tukey. As análises mostraram que o melhor procedimento para preparar sementes de Dalbergia miscolobium é o tratamento em que há uma hidratação seguida pela remoção completa do tegumento, onde 78% das sementes apresentaram coloração uniforme, indicando que as sementes analisadas são de boa qualidade. Os demais tratamentos, hidratação e hidratação seguida de corte, mostraram respectivamente 35% e 41% de sementes viáveis.

Transgressive-regressive cycles in the metalliferous, oil shale-bearing Heath Formation (UpperMississippian), central Montana

Stratigraphy ◽  
2017 ◽  
Vol 14 (1-4) ◽  
pp. 97-122 ◽  
Author(s):  
Julie A. Dumoulin ◽  
Craig A. Johnson ◽  
Karen D. Kelley ◽  
Palma Jarboe ◽  
Paul Hackley ◽  
...  
Keyword(s):  
Oil Shale ◽  
Central Montana

The use of insoluble matter of Moroccan oil shale for removal of dyes from aqueous solution

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methylene Blue ◽  
Oil Shale ◽  
Heating Temperature ◽  
Blue Dye ◽  
Adsorption Capacities ◽  
Experimental Parameters ◽  
Initial Ph ◽  
New Material ◽  
Activating Agent ◽  
Moderate Cost

The study aims to use an adsorbent natural based of Moroccan oil shale of Timahdit area (Y layer) in a physical-chemical adsorption process for treating industrial discharges colorful. The used adsorbent is the insoluble party of the sub-critical extraction of decarbonized oil shale of Timahdit. The tests performed on the methylene blue (MB), showed a strong elimination in the first 10 minutes. The influences of various experimental parameters were studied: mass ratio of adsorbent, time and temperature of thermal treatment, contact time, pH of MB and heating temperature of solution on the parameters of material were studied. The experimental results have shown that the adsorption of methylene blue dye by the adsorbent is more than 90% at initial pH a range 6-7 at room temperature for 30 minutes. The process is simple and the adsorbent produced is a new material with interesting adsorption capacities of moderate cost which does not require an activating agent and can be used as industrial adsorbent for the decontamination of effluents containing organic pollutants.

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