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M.G.Y.L. Mahagamage and Pathmalal M. Manage

Abstract

Typhoid or enteric fever is a worldwide infection caused by the bacterium Salmonella enterica. In Sri Lanka, 12,823 Salmonella positive cases were recorded and 133 cases were recorded from Anuradhapura district during 2005 to 2014. Therefore, the study was carried out to identify the microbiological and chemical contamination status of forty-four water sources in Anuradhapura area during October 2016. The study was focused to determine total coliform, faecal coliform, Salmonella spp. and Shigella spp. contamination along with some physico-chemical parameters of both ground and surface water. Sampling, transportation, and analysis were performed following standard protocols. Results of the study revealed that almost all sampling locations were contaminated with both total and E. coli bacteria and the values were not within the World Health Organization and Sri Lanka Standards drinking water quality standards. Around 32% of sampling locations were positive for Salmonella spp. and among them, 2 spring sampling locations are being highly used to extract water for drinking. However, Shigella spp. was not recorded during the study period. Majority of the sampling points were not within the Sri Lanka drinking water standards for COD and 25% sampling locations were recorded greater than 750 μS∙cm−1 conductivity. Also, 55% of locations recorded very hard water where the highest values were recorded in Padaviya. The tested other water quality parameters: NO2-N, NH3-N, and total phosphate (TP) concentrations were found within the Sri Lanka drinking water standards. PCA analysis revealed that sampling locations were grouped into three groups such as; well water, tank water and springs.

Open access

Lei Su, Zongqiang Xie, Wenting Xu and Changming Zhao

Abstract

Mixed evergreen-deciduous broadleaved forest is the transitional type of evergreen broadleaved forest and deciduous broadleaved forest, and plays a unique eco-hydrologic role in terrestrial ecosystem. We investigated the spatio-temporal patterns of throughfall volume of the forest type in Shennongjia, central China. The results indicated that throughfall represented 84.8% of gross rainfall in the forest. The mean CV (coefficient of variation) of throughfall was 27.27%. Inter-event variability in stand-scale throughfall generation can be substantially altered due to changes in rainfall characteristics, throughfall CV decreased with increasing rainfall amount and intensity, and reached a quasi-constant level when rainfall amount reached 25 mm or rainfall intensity reached 2 mm h−1. During the leafed period, the spatial pattern of throughfall was highly temporal stable, which may result in spatial heterogeneity of soil moisture.

Open access

Judyta Bąk and Andrzej Kucharski

Abstract

We give a proposal of generalization of the Freese–Nation property for topological spaces. We introduce a few properties related to Freese–Nation property: FNS, FN, FNS*, FNI. This article presents some relationship between these concepts. We show that spaces with the FNS property satisfy ccc and any product of such spaces also satisfies ccc. We show that all metrizable spaces have the FN property.

Open access

Volodymyr Bulgakov, Semjons Ivanovs, Igor Safchenko, Andrii Boris and Petro Rychlivskyj

Abstract

Due to the high energy intensity of lifting of deep-seated table root crops, their growth develops mainly in light sandy-loam soils, in which it is possible to transfer a heap of root crops to the separating devices in order to facilitate the qualitative separation. Therefore, issue of lifting of deep-seated table root crops at minimal energy consumption and labour costs is an important scientific and practical task, which would allow expansion of cultivation of deep-seated table root vegetables to heavy soils. Research was conducted by means of a theoretical method utilizing elements of theoretical mechanics with subsequent processing of results by means of PC. Mathematical model and resulting energy cost dependences were constructed on the basis of the device parameters for soil loosening and lifting of deep-seated table root crops. Refined mathematical model of the process of lifting of deep-seated root crops made it possible to find out scientific and technical preconditions for the development of lifting devices with minimal energy consumption.

Open access

Adam Makowka and Beata Pospiech

Abstract

Polymer inclusion membrane (PIM) containing cellulose triacetate (CTA) as a polymer matrix and 2-nitrophenyl octyl ether (NPOE) as a plasticizer was developed. This membrane also contained di(2-ethylhexyl)phosphoric acid (D2EHPA) and tributyl phosphate (TBP) as the carriers of metal ions. The facilitated transport of lanthanum(III) from aqueous nitrate(V) solutions across PIM was studied. It was observed that metal ions were transported from the source phase into 2M H2SO4 as the receiving phase. The transport through PIM with D2EHPA as the ion carrier was found as the more effective method of lanthanum(III) removal from the aqueous solution than transport through PIM with TBP as the ion carrier.

Open access

Ewa Marczak, Piotr Marczak, Sławomir Sztajnowski and Barbara Lipp-Symonowicz

Abstract

The aim of the paper is to assess the range and the mechanisms of transformations of the molecular structure and the physical microstructure of polyacrylonitrile (PAN) fibers produced by various manufacturers under the influence of thermal treatment in different conditions. The thermal treatments were carried out in different media (such as air, water, and steam), at various temperatures, and using different periods of treatment. Changes in the molecular structure were assessed using infrared (IR) absorption spectroscopy and evaluation of the differences in molecular cohesion energy of the fiber material during the dissolution processes. Changes in the fibers’ physical microstructure were investigated using densitometric, IR spectrophotometric, and X-ray diffraction methods; for assessment of both the reconstruction process of the paracrystalline matter of the fibers and the changes in the fibers’ total orientation, interferential polarization microscopy was used.

Open access

Anna Pietrzak and Aleksandra Tokarz

Abstract

Achievement motivation is a distinguishing disposition in elite and non-elite athletes. Implicit theories and competence perception influence the types of achievement goals and constitute separate achievement motivation dispositions. The context of sport promotes various achievement goals and implicit theories about athletic competence. For this reason, scientific research should focus on the intrapersonal profiles of achievement motivation dispositions (achievement goals, implicit theories, and competence perception) instead of specifying only one of them. This study explores differences between elite and non-elite athletes in terms of intrapersonal profiles of achievement motivation dispositions. 54 elite and 50 non-elite track and field athletes took part in the study. The results suggest that athletes tend to perceive their competence accurately. Cluster analysis of the studied dispositions was conducted. The clusters present sets of achievement dispositions that vary in intensity. Moreover, the results present trends of the differences between elite and non-elite athletes in two of the three clusters obtained in the study.

Open access

Alok Dhaundiyal and Suraj Bhan Singh

Abstract

This paper investigates the effect of non-linear thermal profile on the numerical solution of the multi-reaction model. According to the practical perspective, the temperature distribution at a different section of pyrolysis reactor is not necessarily following the ideal thermal history; therefore, it is necessary to predict the behaviour of the system for the higher degree of freedom. TG thermogram is obtained by the thermal degradation of pine needles sample in the thermogravimetric analyser (TGA). The activation energy, frequency factor, reaction order and the scale, shape and location parameters of a stochastic function are estimated for the non-linear parabolic thermal profile. The conventional Laplace integral is used to approximate the multi-reaction model. Activation energy obtained for the non-thermal profile lies in the range of 57.5–60 kJ·mol−1, whereas the frequency factor varies from 103–105 min-1. The obtained value of reaction order (n) lies in the domain of (0.9, 1.6).

Open access

Gian Luigi Forti

Abstract

Investigating Hyers–Ulam stability of the additive Cauchy equation with domain in a group G, in order to obtain an additive function approximating the given almost additive one we need some properties of G, starting from commutativity to others more sophisticated. The aim of this survey is to present these properties and compare, as far as possible, the classes of groups involved.