results the soil was largely composed of silt and clay (silt:41 - 42%, clay: 40 - 43%, sand: 15 - 18%). the average moisture content of the saturated soil was 12.96%,; average electricity conductivity was 18.64 dsm-1; average ph of the paste was 8.36; and average percentage of organic carbon was 0.19%. result of the laboratory analysis reported the average content of total nitrogen as 0.026%, p...

‎we describe a new type of presentation that‎, ‎when consistent‎, ‎describes a polycyclic group‎. ‎this presentation is obtained by‎ ‎refining a series of normal subgroups with‎ ‎abelian sections‎. ‎these presentations can be described effectively in‎ ‎computer-algebra-systems like {scshape gap} or ‎{scshape magma}‎. ‎we study these ‎presentations and‎, ‎in particular‎, ‎we obtain consistency c...

Altan derivatives of polycyclic conjugated hydrocarbons were recently introduced and studied in theoretical organic chemistry. We now provide a generalization of the altan concept, applicable to any graph. Several earlier noticed topological properties of altan derivatives of polycyclic conjugated hydrocarbons are shown to be the properties of all altan derivatives of all graphs. Among these ar...

It is well known that any polycyclic group, and hence any finitely generated nilpotent group, can be embedded into GLn(Z) for an appropriate n ∈ N; that is, each element in the group has a unique matrix representation. An algorithm to determine this embedding was presented in [6]. In this paper, we determine the complexity of the crux of the algorithm and the dimension of the matrices produced ...

an aquifer located within a petroleum processing plant in moín, costa rica, suffers hydrocarbon pollution. this study aimed to determine the ability of indigenous microorganisms from this site to degrade polycyclic aromatic hydrocarbons (pahs) to evaluate the feasibility of an eventual bioremediation process. aerobic conditions were found in the aquifer, while microbial analyses of the groundw...

We announce the development and implementation of a new GAP package PCQL. This facilitates the computation of consistent polycyclic presentations for polycyclic quotients of groups defined by a so-called finite L-presentation. This type of presentation incorporates all finite presentations as well as certain infinite presentations. The algorithm allows a variety of polycyclic quotients ranging ...

In this paper we generalize the notion of cyclicity of codes, that is, θ-polycyclic codes and θ-sequential codes. It is shown that for a code C, C is θ-polycyclic (θ-sequential) if and only if its dual C⊥ is θ−1-sequential (θ−1-polycyclic). Furthermore, we study central θ-constacyclic codes. Mathematics Subject Classification: Primary 94B60; Secondary 94B15, 16W20

A total of 10 surface soil samples representing the entire area of Linfen City were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons. The total polycyclic aromatic hydrocarbon concentration ranged from 1.1 to 63.7 microg g(-1). Analysis of the sources of contamination revealed that polycyclic aromatic hydrocarbons in the soil were derived from combustion sources. S...

Polycyclic guanidine natural products, such as batzelladines A, E, and F, exhibit a rich and diverse array of interesting biological activities (Figure 1). Some polycyclic guanidine alkaloids have been shown to inhibit protein–protein interactions, including the binding of HIV gp120 to CD4 on human T-cells. Furthermore, many polycyclic guanidines display potent antiviral, antimalarial, and immu...

The structural features of polycyclic polyether natural products can, in some cases, be traced to their biosynthetic origin. However in case that are less well understood, only biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades are proposed. We summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers (see s...