Frasnian bryozoans (Late Devonian) from the Khoshyeilagh Section,Alborz Mountains (northern Iran)

A bryozoan fauna containing seven species is described from the Upper Frasnian (Upper Devonian) rocks in the Khoshyeilagh Section, Alborz Mountains (northern Iran). The studied bryozoan assemblage includes one new trepostome species, Eridotrypella alborzensis sp. nov., an additional four species identified at species level: two trepostomes, Minussina akkayaensis Volkova, 1974 and Leptotrypella inaudita Morozova, 1961, and two rhabdomesine cryptostomes, Bigeyella mariae (Morozova, 1961) and Saffordotaxis multispinata (Morozova, 1955). Furthermore, two species are described in open nomenclature: the trepostome Schulgina sp. and the rhabdomesine cryptostome Nicklesopora sp. The studied fauna shows a close similarity at the species level between northern Iran and the Altai-Sayan Folded Belt (Russia), south China, and Transcaucasia.     

Ignition of Hydrocarbon–Oxygen Mixtures by Means of a Nanosecond Surface Dielectric Barrier Discharge

Ignition of hydrocarbon–oxygen mixtures by means of a nanosecond surface dielectric barrier discharge (NSDBD) was studied experimentally. The propagation velocity of the flame wave and the ignition delay time in mixtures of oxygen with methane, ethane, ethylene, and dimethyl ether were measured using a high-speed camera. The experiments were carried out at room temperature and gas mixture pressures in the range of 0.75–1.25 atm. It is shown that, for all hydrocarbons under study, the flame velocity decreases with reducing pressure and stoichiometric ratio, as well as when the mixture is diluted with molecular nitrogen. Theoretical analysis of the processes in the NSDBD plasma and measurements of the flame velocity in hydrocarbon-containing mixtures without plasma agree qualitatively with the measurement results, except for the increasing dependence of the flame velocity on the pressure, which is decreasing in experiments without a discharge plasma.     

Energy Applications of Magnetocaloric Materials

The need for energy‐efficient and environmentally friendly refrigeration, heat pumping, air conditioning, and thermal energy harvesting systems is currently more urgent than ever. Magnetocaloric energy conversion is among the best available alternatives for achieving these technological goals and has been the subject of substantial basic and applied research over the last two decades. The subject is strongly interdisciplinary, requiring proper understanding and efficient integration of knowledge in different specialized fields. This review article presents a historical and up‐to‐date account of the energy‐related applications of magnetocaloric materials and information about their processing and magnetic fields, thermodynamics, heat transfer, and other relevant characteristics. The article also discusses the conceptual design of magnetocaloric refrigeration and power generation systems and some guidelines for future research in the field.     

The influence of nitrogen,water and competition on the vegetative and reproductive growth of common ragweed (<Emphasis Type="Italic">Ambrosia</Emphasis><Emphasis Type="Italic">artemisiifolia</Emphasis> L.)

As common ragweed (Ambrosia artemisiifolia L.) spreads across Europe and other regions, it is becoming both a health and an economic threat. To better understand which environmental conditions facilitate the spread of the invasive species, in 2010, a greenhouse experiment was conducted determining the effects of various nitrogen levels (10, 50 and 100 kg N/ha), soil moisture level (low and high) and competition levels (no competition, medium competition and high competition) on the growth parameters of ragweed. Single-grown ragweed responded favourably to the medium nitrogen and water increase, whereas the ragweed growth parameters in competition stands increased only when high levels of nitrogen and water were added. High competition reduced the total dry matter of ragweed by up to 83%, but the ragweed continued to increase its relative growth rate during the full-flowering stage and allocate its dry matter to reproductive parts, producing up to 70 seeds per plant. Ragweed is a poor competitor when there is high resource availability; however, under disturbance and in the shortage of nutrients and water conditions, the intensity of competition decreases and the ragweed performance is minimally affected. The addition of medium levels of nitrogen to promote the growth of competitive species, prevention of disturbance and establishment of plant communities with stress-tolerant species is measures that should help to prevent the further spread of ragweed.     

Character of morphoses caused in the Barley (Hordeum distichum L.) spike by 2-Methyl-4-Chlorophenoxycetil acid (MCPA)

The preparation of MCPA had no formative effect on the shoot apex although it affected the development of lateral buds formed at the sides. As soon as the compound ceased to act the development of the spike continued normally. The formative effect of MCPA is displayed in the structure of the ear by a partial or complete reduction of its internodes. The inhibitory action of the preparation is sometimes reflected in a blockade of the formation of lateral shoots in a part of one or both orthostichs, or else the lateral bud is initiated but does not continue to develop and thus a branchless node is produced. Occasionally, on the contrary, the preparation has a stimulating effect; segments of the lateral stem of the first order are elongated and develop similarly to the main stem which brings about the so-called “branching” of the spike frequently imitating dichotomy. Rich branching occurs on stimulating several lateral stems. A frequently met morphosis is a locally disturbed distichy, and a decussation of orthostichs or their rotating by an angle of less than 90° and a disturbance in the normal course of mesotonic branching. The formation of apparent or true flower whorls formed in consequence to a reduction of the ear internodes or a disturbance of distichy is usually connected with the reduction of individual inflorescence parts, with an increase in the number of inflorescence parts, with their partial or complete cohesion and with a change of their position.