Characteristics Of Different Sources Research Articles

Quantifying the Contribution of Soil Heavy Metals to Ecological and Health Risk Sources

Quantifying the risk of soil heavy metal sources can identify the main pollution sources. It can provide a scientific basis for reducing the ecological and human health risks of soil heavy metals. Taking the shallow soil in a Pb-Zn mine watershed in northern Guangxi as a research object， ecological and human health risk assessments were conducted using potential ecological risk assessment （RI） and human health risk assessment （HRA）， and the source apportionment of soil heavy metals was completed using the absolute principal component-multiple linear regression receptor （APCS-MLR） model and random forest （RF） model. Then， a combined risk assessment model， consisting of RI， HRA， and APCS-MLR， was used to quantify the risk of soil heavy metal sources. The results showed that the contents of Pb， Zn， Cu， and Cd exceeded the environmental screening values for agricultural land with mean values of 342.77， 693.34， 61.27， and 3.08 mg·kg-1， respectively， and there was a certain degree of contamination. Pb， Cr， and As were the main health risk impact factors， with higher health risks for children than for adults. Three sources were identified： mining activities （Source Ⅰ）， soil parent material sources and original formation （Source Ⅱ）， and unknown sources. Pb， Zn， Cu， and Cd were mainly derived from Source Ⅰ， and Cr and As were controlled by unknown sources and Source Ⅱ. The source risk assessment results of soil heavy metals indicated that the potential ecological risk and non-carcinogenic risk were mainly from Source Ⅰ and Source Ⅱ， and carcinogenic risk was mainly from unknown sources. The unknown sources had a high proportion in source apportionment and risk assessment， and should be further researched to provide scientific basis for soil heavy metal control. The combined risk assessment model based on source analysis， focusing on the risk characteristics of different sources， can accurately identify high-risk pollution sources. It is a more reasonable and reliable risk assessment method.

On density measurement using various radiation sources: Cs-137, X-ray and pulsed neutron

The use of controllable sources for density measurement is gaining more attention as a safer alternative to chemical sources, since chemical sources pose risks to both humans and the environment. Nuclear density tools using electronically controlled sources, such as X-ray tubes and pulsed neutron generators, are being researched as a replacement for radiological gamma sources such as Cs-137. This study, based on the real gamma density tool structure, optimizes the design of the X-ray and pulsed neutron-gamma density tools, providing a reference for the optimization of source-less density tools. Firstly, the study gives a comparison of density measurement using three sources through a combination of theory and simulation results. And the performance of the tools is evaluated using indicators such as detection efficiency, formation density sensitivity, and depth of investigation. Finally, based on the characteristics of different sources, the aforementioned indicators are balanced to obtain the optimal value of the source-to-detector distance, thus the structure of the X-ray density tool and pulsed neutron-gamma density tool are optimized.

Fermentation characteristics of different sources of dietary fiber in vitro and impacts on growth performance, nutrient digestibility and blood para-meters of piglets

This study aimed to assess the effect of various source of high-fiber ingredients on growth performance, apparent digestibility of nutrients, and blood para- meters of piglets by investigating their in vitro fermentation characteristics. A total of 300 healthy crossbred piglets were randomly allocated to one of five diets including corn-soybean meal basal diet (CON), sugar beet pulp (SBP), soybean hull (SBH), fermented distillers’ grains (FDG), and kelp powder (KP). In vitro fermentation analysis revealed that the predominant short-chain fatty acids produced were acetate and valerate. Sugar beet pulp and kelp powder exhibited rapid fermentation rates, in contrast to SBH, oat bran, and FDG. The apparent total tract digestibility of dry matter (P < 0.05), gross energy (P < 0.05), and crude protein were decreased (P < 0.001) in different fiber diets than the CON diet. The serum concentration of threonine was increased by feeding fibers diets (P < 0.05). In conclusion, a diet containing 3% SBP (with a soluble-to-insoluble dietary fiber ratio of 17.04%) showed the best effects on increasing nutrients digestibility and serum amino acid concentrations. These findings may inform future applications of SBP in piglet nutrition.

How source of product acquisition affects consumers' reliance on positive word-of-mouth: a mental imagery perspective

PurposeThis research focuses on the role of product acquisition cues in positive word-of-mouth (PWOM) content on social media, comparing the characteristics of different sources of product acquisition (purchased vs. gifted) and exploring whether and how they affect consumers' reliance on word-of-mouth (WOM).Design/methodology/approachThe research model was developed based on the mental imagery theory. Two offline experiments and two online experiments were used to test the proposed hypotheses.FindingsThe results show that, compared to the purchased source, the gifted source evokes more positive mental imagery and greater emotional attachment to the product, resulting in greater consumer reliance on PWOM. In addition, the effect of the source of product acquisition on reliance on PWOM was stronger for experiential (vs. material) products and for consumers with higher interdependent (vs. independent) self-construal.Originality/valueThis research highlights the role of product acquisition cues in PWOM in influencing consumers' evaluation of WOM, while also revealing the processes inherent in how consumers process information through mental imagery. The findings provide a more comprehensive understanding of the antecedents of reliance on WOM and offer new insights and recommendations for management practitioners.

Land cover classification combining Sentinel-1 and Landsat 8 imagery driven by Markov random field with amendment reliability factors

Reliability factors in Markov random field (MRF) could be used to improve classification performance for synthetic aperture radar (SAR) and optical images; however, insufficient utilization of reliability factors based on characteristics of different sources leaves more room for classification improvement. To solve this problem, a Markov random field (MRF) with amendment reliability factors classification algorithm (MRF-ARF) is proposed. The ARF is constructed based on the coarse label field of urban region, and different controlling factors are utilized for different sensor data. Then, ARF is involved into the data energy of MRF, to classify the sand, vegetation, farmland, and urban regions, with the gray level co-occurrence matrix textures of Sentinel-1 imagery and the spectral values of the Landsat 8 imagery. In the experiments, Sentinel-1 and Landsat-8 images are used with overall accuracy and Kappa coefficient to evaluate the proposed algorithm with other algorithms. Results show that the overall accuracy of the proposed algorithm has the superiority of about 20% in overall precision and at least 0.2 in Kappa coefficient than the comparison algorithms. Thus, the problem of insufficient utilization of different sensors data could be solved.

Fast and effective removal of contamination from scalp electrical recordings

ObjectiveTo present a new, automated and fast artefact-removal approach which significantly reduces the effect of contamination in scalp electrical recordings. MethodWe used spectral and temporal characteristics of different sources recorded during a typical scalp electrical recording in order to improve a fast and effective artefact removal approach. Our experiments show that correlation coefficient and spectral gradient of brain components differ from artefactual components. We trained two binary support vector machine classifiers such that one separates brain components from muscle components, and the other separates brain components from mains power and environmental components. We compared the performance of the proposed approach with seven currently used alternatives on three datasets, measuring mains power artefact reduction, muscle artefact reduction and retention of brain neurophysiological responses. ResultsThe proposed approach significantly reduces the main power and muscle contamination from scalp electrical recording without affecting brain neurophysiological responses. None of the competitors outperformed the new approach. ConclusionsThe proposed approach is the best choice for artefact reduction of scalp electrical recordings. Further improvements are possible with improved component analysis algorithms. SignificanceThis paper provides a definitive answer to an important question: Which artefact removal algorithm should be used on scalp electrical recordings?

Research on joint optimal dispatching method for hybrid power system considering system security

Abstract Due to the clear differences in the characteristics of different power sources, it is necessary to take both the economic and security requirements of the power grid into account simultaneously to achieve an optimal operation strategy for a multienergy power system. This paper focuses on the optimal day-ahead dispatching of a hybrid power system that includes wind power, solar photovoltaic power, cascade hydropower, thermal power, and pumped-storage power. Considering the complementary characteristics of these different sources, a day-ahead joint optimal dispatching model of the multi-energy power system is established, with objectives of maximizing the security level, economic benefits and renewable energy consumption. A three-stage method based on Benders decomposition is proposed to solve this complex multiobjective problem. By decoupling the security and economic problems of the hybrid power system, an efficient solution for the scheduling strategy is achieved. The influences of factors such as the diversity of natural scenarios and the security requirements of system operation on the scheduling results are fully discussed in the case study section. The computational efficiencies of the proposed three-stage method and of the direct method are also comparatively analyzed. The simulation results verify the superiority of the proposed scheduling strategy and algorithm.

Young people’s conceptions of political information

PurposeThe purpose of this paper is to explore young people’s conceptions of political information. The study sought to identify what political information sources young people encounter, how they construe these sources and the messages they communicate, and how the information experiences of young people may be better understood to inform information literacy interventions to support the development of political agency.Design/methodology/approachUsing personal construct theory as a conceptual framework, repertory grid (RG) interviews were used to explore the different ways in which 23 young people aged 14-15 from a town in Northern England conceive of political information and how they evaluate its quality and authority.FindingsThe study identified the sources of information young people engage with for finding and receiving what they understand as political information. The results from the RG interviews indicated that young people use a wide range of sources of political information to become informed about politics and the world around them. These sources of information include family, friends, teachers, television news, newspapers, radio shows, comedy shows, social media and community meetings. Participants were aware that they passively encounter information sources as well as actively engage in debate and discussion with other sources. Some participants had difficulty critically evaluating the political information sources they encounter. The nature of young people’s experiences of political information varied greatly. The degree of complexity in the experiences of political information varied not only between participants but was also dependent on their particular relationship with the information sources under scrutiny.Research limitations/implicationsThe paper has implications for personal construct analysis as a research approach broadly, from the point of view of its use within library and information science research. It is the first study to apply the personal construct approach to the study of young people’s political information use and to consider implications for information literacy support that would have been difficult to access using other approaches.Practical implicationsThe paper provides insight into an understudied area; that of young people’s conceptions of political information. This insight may be used to inform the improvement of political information provision and information literacy support for young people.Social implicationsA deeper understanding of the different ways in which young people identify, engage with and use information for political purposes may contribute to a clearer understanding of young people’s information needs, ideally leading to improved political education and a strengthened democratic process.Originality/valueThe paper explores a relatively under-researched area of library and information science research, and does so using a relatively under-used method in the domain. Insights into the perceived characteristics of different sources of political information are novel and contribute to the development of information behaviour and information literacy fields in terms of information for empowerment and democracy.

Evaluation of Recyclability of Fibrous Raw Materials from Scums in Papermaking Process

As the meaning of dictionary terminology, scum refers to a layer of impurities that accumulates at the surface of a liquid. In papermaking process, scum indicates the floated solid waste generated by a flotation process during the primary wastewater treatment. In this study, different kinds of stocks and scums collected from newspaper, liner, tissue and fine paper were analysed in details. The purpose of this study was firstly to demonstrate the composition characteristics of different sources of scum, secondly the analysis of environmental hazardous materials, and thirdly the evaluation of reutilization ability of fibrous materials from collected scum. As mentioned the meaning of solid waste, scum was actually differ from the waste sludge in sources, compositions and recycling abilities. In the same manner of waste paper, the sludge which is generated within onsite of papermaking processes would be reused as a raw material. The general compositions of scum from waste water were mainly inorganic ash materials, fine fibre fractions, recycled fibre debries, and ink particles. If the scum is able to reuse as fibrous additives in papermaking process, it could contribute to the savings of running costs in both the subsidiaries of fibrous material and the solid waste treatment with even small quantity.

Sound radiation by distributed quadrupole sources near rigid bodies

An approach is proposed to describe the multipole structure of the sound field radiated as a turbulent jet streamlines a transverse circular cylinder of small diameter, which makes it possible to study the experimentally revealed effect of the dipole radiation shift. It is shown that different methods of acoustic measurements can lead to different determinations of the dipole radiation shift. It is demonstrated that to correctly describe the effect of the dipole radiation shift it is necessary to take into account the phase characteristics of different sources in the field of a turbulent flow; i.e., taking into account the state of distribution of the source is of fundamental importance for calculating the dipole radiation shift.

Undergraduates' source selection behavior: A correspondence analysis

AbstractWith advances in information technologies, a wide variety of sources and channels have been made available to provide access to information. As different sources offer information with varying qualities, evaluating and selecting quality information sources is crucial and has become a key element in bibliographic instruction and information literacy training. Despite efforts in helping them to select optimal sources, individuals choose to use sources that are not necessarily accurate or reliable. Users often turn to information sources that are not suitable to their tasks. This study aims at understanding the relationship between the perception and selection of information sources.Surveying undergraduate students, this study examines three aspects related to their source selection behavior: (1) perceived characteristics of different sources; (2) source characteristics considered to be important for the source selection; and (3) frequently selected/used sources. The study will help understand how users view sources differently and how such perception is related to the source selection behavior. Based on the study findings, suggestions will be made to improve information literacy programs that can support the selection of the best sources.

Spatial Patterns of Natural Polycyclic Aromatic Hydrocarbons in Sediment in the Lower Athabasca River

The Athabasca Oil Sands is one of the four natural oil sands deposits in Northern Alberta, Canada, and are by far the largest oil sand deposit in North America, covering an area of 46,000 km2. Sediment samples were collected from the bed and bank of several tributaries that have naturally occurring exposures of oil sand material. Oil sand deposited along the lower Athabasca River, more than 100 km downstream of naturally occurring oil sand exposures, were also sampled. The levels of alkylated polycyclic aromatic hydrocarbons (PAHs) in samples collected from these various locations ranged from not detected to almost 50 ppm. Using dibenzothiophene/chrysene (C2/D2 vs. C3/D3) double ratio plots, it is possible to approximate the relative degree of degradation or weathering of the PAHs from these various sediment deposits along the lower Athabasca River and its tributaries. Similarly a plot of dibenzothiophene/phenanthrene (D2/P2 vs. D3/P3) indicate the possible origins of the oil. A combination of these plots, D3/P3 vs. D3/C3, was particularly useful in identifying weathering characteristics of different sources of the oil. Comparison of alkylated PAH distributions between the lower Athabasca River and the tributaries show slight differences consistent with different petrogenic sources and/or different weathering patterns.

Urban air pollution by carcinogenic and genotoxic polyaromatic hydrocarbons in the former USSR.

The content of major carcinogenic and genotoxic polyaromatic hydrocarbons (PAH) in urban air, vehicle, and industrial emissions is assessed. A sensitive, specific, and selective method for PAH and nitro-PAH quantitation was developed on the basis of low-temperature luminescence-spectra of frozen polycrystalline solutions. Polyarene contents in urban air and urban industrial emissions, as well as vehicle exhausts, are compared to the Russian Ministry of Health standard of maximal permissible concentration for benzo[a]pyrene in the ambient air. Special attention was paid to the study of PAH profiles and characteristics of different sources. The feasibility of using benzo[a]pyrene to assess PAH content in industrial and vehicle emissions was explored. PAH profiles in the ambient air and local emissions are compared. In addition, genotoxicity of the emissions of coke plant and diesel engine exhausts are compared to their polyarene content.