Hydraulic flow unit classification from core data: case study of the Z gas reservoir, Poland

Permeability and porosity are essential parameters for estimating hydrocarbon production from reservoir rocks. They are combined in an additional factor, the Flow Zone Index (FZI), which is the basis for defining the hydraulic flow unit (HFU). Each HFU is a homogeneous section of a reservoir rock with stable parameters that allow for media flow. Hydraulic flow units are determined from the porosity and permeability of core or well logs. The simple statistical methods are applied for HFU classification and then improve permeability prediction. This paper also shows how to quickly apply the global hydraulic elements (GHE) method for HFU classification. The methodology is tested on the Miocene formation of a deltaic facies from the Carpathian Foredeep in South-Eastern Poland.

Road Safety Analysis of Urban Roads: Case Study of an Italian Municipality

Attention to the most vulnerable road users has grown rapidly over recent decades. The experience gained reveals an important number of fatalities due to accidents in urban branch roads. In this study, an analytical methodology for the calculation of urban branch road safety is proposed. The proposal relies on data collected during road safety inspections; therefore, it can be implemented even when historical data about traffic volume or accidents are not available. It permits us to identify geometric, physical, functional, and transport-related defects, and elements which are causal factors of road accidents, in order to assess the risk of death or serious injuries for users. Traffic volume, average speed, and expected consequences on vulnerable road users in case of an accident allow us to calculate both the level of danger of each homogeneous section which composes the road, and the hazard index of the overall branch. A case study is presented to implement the proposed methodology. The strategy proposed by the authors could have a significant impact on the risk management of urban roads, and could be used in decision-making processes to design safer roads and improve the safety of existing roads.

Phylogeny and taxonomy of Habenaria leprieurii, H. alpestris and H. sect. Microdactylae (Orchidaceae), with descriptions of two new taxa

Habenaria leprieurii and H. alpestris both have histories of misleading and conflicting taxonomic identifications. We investigated the taxonomy, phylogenetic relationships, and sectional classification of those and related species. Examinations of type specimens and large numbers of additional live and herborized samples revealed that H. schwackei, H. amazonica, and H. platydactyla are conspecific with H. leprieurii and are characterized by having a white corolla and a long pedicel. The species previously treated as H. leprieurii, is H. cruegerii, of which H. culmiformis is a synonym and are characterized by the green flowers, short pedicel and the straight ovary, parallel to the inflorescence axis, curved only in the apex. A species from central-western Brazil, previously treated as H. alpestris, corresponds to a new species, described here as H. omissa, while H. alpestris is conspecific with H. melanopoda. We propose a new circumscription for H. sect. microdactylae, including H. leprieurii, H. heptadactyla, H. cruegerii, and the newly described H. omissa and H. cruegeri var. flaviflora—which now form a morphologically homogeneous section. An identification key, plus descriptions, notes, illustrations, and lists of specimens for each species are presented.

Homogeneous variational problems and Lagrangian sections

We define a canonical line bundle over the slit tangent bundle of a manifold, and define a Lagrangian section to be a homogeneous section of this line bundle. When a regularity condition is satisfied the Lagrangian section gives rise to local Finsler functions. For each such section we demonstrate how to construct a canonically parametrized family of geodesics, such that the geodesics of the local Finsler functions are reparametrizations.

Advanced numerical simulation of collapsible earth dams

This paper presents a methodology for advanced numerical analysis of earth dams, considering all design stages. It also includes transient analysis of safety factors and can be applied to general three-dimensional conditions, considering unsaturated materials and the interrelation between hydraulic and mechanical phenomena by simultaneously solving equilibrium and continuity conditions. The methodology has been successfully implemented in a finite element program and applied to the analysis of earth dams with sections composed of soils at optimum, dry of optimum, and mixed compaction conditions. The dry section is intended to simulate the so-called “Alka-Seltzer” dams, constructed with poorly compacted and dry material, thus resulting in a meta-stable and collapsible structure. The results show that it is possible to design a less expensive mixed section with approximately the same behavior and in some cases even better performance when compared with the homogeneous section at optimum conditions. This is achieved by strategically placing the optimum materials in the most stressed zones of the earth fill. The safety factor analyses show the importance of considering coupled effects in collapsible dams. In such cases, failure can be simulated in the upstream slope during the first reservoir impounding, as has been observed in some actual cases.

The Plantation States as a Sub-Region of the Post-Bellum South

Recent work by Reid, Higgs, Sutch and Ransom and others is an indication that increasing scholarly attention is being addressed to the post-bellum southern economy. The object of this note is to raise a word of caution with respect to work done on the South in which the latter is taken to mean a more or less homogeneous section of the nation. In particular I would suggest that (a) substantial and important variations exist within this region, differences which may even be obscured when the South is divided along the usual Bureau of the Census sub-regional borders, and (b) a disaggregation of the South into more functional units than that of the Census Bureau may provide insights into the relative poverty experienced in the region, particularly of the black population in this area in the years before 1910.

Medieval Roofs with Base-Crucks and Short Principals

SummaryThis paper examines, from two points of view, a collection of some ninety buildings with base-cruck trusses, and a further group of related buildings, particularly those whose roof trusses incorporate short principals. Examination of the social status of the buildings shows that they belonged to a remarkably homogeneous section of feudal society, and their distribution can be explained largely in terms of the social connections of a class, with some further influence of local schools of carpentry. The typological development of base-crucks and short principals is traced from their twelfth- or thirteenth-century origins to a fifteenth-century devolution into various local sub-types.