Numerical study of the normal current density behaviour in a narrow - gap glow discharge

A numerical study of normal glow discharge properties was performed in the case of small electrodes separations (0.05-0.4 cm) and moderate gas pressures (10-46 Torr). A recently observed new experimental effect of a considerable reduction in the normal current density for smaller discharge lengths was analyzed both by means of 2D fluid model and by a minimal 1D drift model of gas discharge. A good agreement between theoretical and experimental behaviour was demonstrated. An influence of the electrodes separation and of the gas heating on the value of the normal current density is discussed.Comment: 20 pages, 4 figure

The blood transfer conductance for nitric oxide: infinite vs. finite θNO

Whether the specific blood transfer conductance for nitric oxide (NO) with hemoglobin (θNO) is finite or infinite is controversial but important in the calculation of alveolar capillary membrane conductance (DmCO) and pulmonary capillary blood volume (VC) from values of lung diffusing capacity for carbon monoxide (DLCO) and nitric oxide (DLNO). In this review, we discuss the background associated with θNO, explore the resulting values of DmCO and VC when applying either assumption, and investigate the mathematical underpinnings of DmCO and VC calculations. In general, both assumptions yield reasonable rest and exercise DmCO and VC values. However, the finite θNO assumption demonstrates increasing VC, but not DmCO, with submaximal exercise. At relatively high, but physiologic, DLNO/DLCO ratios both assumptions can result in asymptotic behavior for VC values, and under the finite θNO assumption, DmCO values. In conclusion, we feel that the assumptions associated with a finite θNO require further in vivo validation against an established method before widespread research and clinical use

nnovative Seasonal Migrations and Subsistence System of the Mobile Pastoralists of the Desert-Steppe Zone of Eurasia:role of social groups

The study of the economic system of the earliest nomads which inhabited the Eurasian desert-steppe belt in 5000-2000 is a relevant task of contemporary studies. The data on the organization of living space and the role of social groups of early prehistoric pastoralists in the exploitation of open steppe resources are scarce. The paper presents a new methodological approach to searching camps of the earliest pastoralists. The application of this approach enabled the archaeologists to discover numerous seasonal camps in the Sal-Manych Ridge located in the western part of the Eurasian steppes, including Eneolithic camps dated to 4200-3600 BC. The study of the occupation layers at the sites, evaluation of the productivity of pasture systems made it possible to categorize such sites as short-term seasonal camps occupied by pastoralists, evaluate the role of social groups in the organization of innovative seasonal migrations and reconstruct their subsistence system. The camps emerged as a result of developing pastoral economic strategy in the Lower Don region and the abutting areas reflecting the role of special social groups of pastoralists who managed to organize seasonal moves and address the issue of exploiting pastures located beyond the permanently occupied area

Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass‐loss rate and stabilization

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models

Reading tea leaves worldwide: decoupled drivers of initial litter decomposition mass-loss rate and stabilisation

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large-scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial mass-loss rates and stabilization factors of plant-derived carbon, using the Tea Bag Index (TBI). The stabilization factor quantifies the degree to which easy-to-degrade components accumulate during early-stage decomposition (e.g. by environmental limitations). However, agriculture and an interaction between moisture and temperature led to a decoupling between initial mass-loss rates and stabilization, notably in colder locations. Using TBI improved mass-loss estimates of natural litter compared to models that ignored stabilization. Ignoring the transformation of dead plant material to more recalcitrant substances during early-stage decomposition, and the environmental control of this transformation, could overestimate carbon losses during early decomposition in carbon cycle models