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61.
ABSTRACT Arsenic is an element frequently associated with mining operations around the world. Its long-term stability in mine tailings may be a problem due to its particular chemical properties. It has been frequently observed that arsenic goes into dissolution at conditions where other metals are stable. This paper presents a case study of a tailing site where arsenic has been periodically released. Data collected over a three-year period are presented and analysed. The paper identifies the causes underlying the periodic arsenic release and defines the treatment methods in order to correct the situation. 相似文献
62.
Kostas Tsagkaris Maria Akezidou Aristi Galani Panagiotis Demestichas 《International Journal of Network Management》2012,22(3):235-260
Future networks will need to accommodate a significantly augmented user demand, mainly stemming from the wireless and mobile domains. In general, the emerging radio landscape will comprise multiple, collaborating radio access networks (RANs) able to operate a plethora of diverse radio access technologies (RATs), variant types of mobile terminals (MTs), with the ability to choose among various supported RANs/RATs and, in addition, both devices and networks with dynamic spectrum access capabilities that allow the sharing and/or optimization of spectrum usage among different systems. The above will stress network operators for developing mechanisms to confront the challenges and to leverage the opportunities posed by such a versatile radio environment. In particular, the situation calls for adaptive and flexible management paradigms that are able to dynamically manage network elements and terminals, thus ensuring the great availability and efficient usage of spectrum and other radio resources. Framed within the above, this paper considers a cognitive network management architecture, which is destined for optimized management of future wireless networks operating in versatile radio environments, and presents a performance evaluation methodology, which was set up for measuring the signalling loads that the operation of the architecture will bring to the managed network. The methodology is analytically described, and useful results with respect to the signalling load produced for management signalling purposes in an indicative scenario are presented and analysed. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
63.
Roniotis A Sakkalis V Karatzanis I Zervakis ME Marias K 《IEEE transactions on information technology in biomedicine》2012,16(3):299-307
Glioma is one of the most aggressive types of brain tumor. Several mathematical models have been developed during the past two decades, toward simulating the mechanisms that govern the development of glioma. The most common models use the diffusion-reaction equation (DRE) for simulating the spatiotemporal variation of tumor cell concentration. Nevertheless, despite the applications presented, there has been little work on studying the details of the mathematical solution and implementation of the 3-D diffusion model and presenting a qualitative analysis of the algorithmic results. This paper presents a complete mathematical framework on the solution of the DRE using different numerical schemes. This framework takes into account all characteristics of the latest models, such as brain tissue heterogeneity, anisotropic tumor cell migration, chemotherapy, and resection modeling. The different numerical schemes presented have been evaluated based upon the degree to which the DRE exact solution is approximated. Experiments have been conducted both on real datasets and a test case for which there is a known algebraic expression of the solution. Thus, it is possible to calculate the accuracy of the different models. 相似文献
64.
65.
Cellular uptake and cytotoxic impact of chemically functionalized and polymer-coated carbon nanotubes 总被引:1,自引:0,他引:1
Ali-Boucetta H Al-Jamal KT Müller KH Li S Porter AE Eddaoudi A Prato M Bianco A Kostarelos K 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(22):3230-3238
The impact of nanomaterials such as carbon nanotubes on biological matter is a topic of increasing interest and concern and requires a multifaceted approach to be resolved. A modified cytotoxic (lactate dehydrogenase (LDH)) assay is developed in an attempt to offer a valid and reliable methodology for screening carbon nanotube toxicity in vitro. Two of the most widely used types of surface-modified multiwalled carbon nanotubes (MWNTs) are tested: ammonium-functionalized MWNTs (MWNT-NH3+ ) and Pluronic F127 coated MWNTs (MWNT:F127). Chemically functionalized MWNTs show significantly greater cellular uptake into lung epithelial A549 cells compared to the non-covalently Pluronic F127-coated MWNTs. In spite of this, MWNT:F127 exhibit enhanced cytotoxicity according to the modified LDH assay. The validity of the modified LDH assay is further validated by direct comparison with other less reliable or accurate cytotoxicity assays. These findings indicate the reliability of the modified LDH assay as a screening tool to assess carbon nanotube cytotoxicity and illustrate that high levels of carbon nanotube cellular internalization do not necessarily lead to adverse responses. 相似文献
66.
Kostas Kandylis Panayiotis Nikokyris Dimitrios Liamadis Kostas Deligiannis 《Journal of the science of food and agriculture》1992,58(3):291-299
The value of cotton seed cake as a source of crude protein in sheep diets was studied. The cotton seed cake was incorporated into diets at levels of 0, 15 and 30% after replacement of soya bean meal and was fed ad libitum to growing lambs. The diets were formulated to be isonitrogenous and isocaloric. Sixteen lambs (8 male and 8 female) having an average liveweight of approximately 13.6 kg were used in each treatment. After being fed for 62 days and having reached a liveweight of approximately 26.7 kg, five male lambs from each treatment were slaughtered and carcass data were collected. Results of the growth trial showed that there were no significant differences in feedlot performance or carcass analysis among the lambs fed these diets. The dressing percentage was slightly higher (P > 0.05) for lambs fed the 15% cotton seed cake compared with the 30% cotton seed cake and control diets. However, the final weights were substantially higher (P < 0.001) and live average daily gains and feed intakes were all higher (P < 0.10) for male animals. It was concluded that cotton seed cake is an acceptable feed ingredient for growing sheep and can satisfactorily replace soya bean meal as a source of protein in ruminant diets, a feedstuff locally produced in Greece and substantially cheaper than the imported soya bean meal. 相似文献
67.
Kostas Tsagkaris Gerard Nguengang Aristi Galani Imen Grida Ben Yahia Majid Ghader Alexandros Kaloxylos Markus Gruber Apostolis Kousaridas Mathieu Bouet Stylianos Georgoulas Aimilia Bantouna Nancy Alonistioti Panagiotis Demestichas 《International Journal of Network Management》2013,23(6):402-423
Academic and industrial research initiatives have sought to make fully autonomic networks a reality. Some of these initiatives pursued a holistic approach, while others focused on setting up functionalities for specific networking domains. These efforts did not succeed in being extensively deployed, because the goals of network operators were not satisfactorily met. These goals include unification of management operations, enablement of end‐to‐end management and enhancement of the overall system performance in a trusted way, while reducing management cost. In this paper, we analyse a set of existing autonomic management architectures and frameworks with respect to a selected set of criteria. We then identify missing parts and challenges and propose a framework to unify the most promising attributes towards a novel approach of realization of autonomic networking management. We call this proposal Unified Management Framework (UMF). Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
68.
Stavros G. Stavrinides Kostas Papathanasiou Antonios N. Anagnostopoulos 《International Journal of Electronics》2013,100(2):233-247
In this paper, a new approach in identifying chaotic behaviour of nonlinear circuits is presented. This approach could be very useful to circuit designers, whether they pursue a chaotic behaviour or not. Simulation tools used for radio-frequency circuit design (Cadence SpectreRF), initially developed to characterise harmonic oscillators, are now utilised to detect chaotic behaviour, as well as routes to chaotic mode of operation. Specifically, Periodic Steady State Convergence Norm is used for the first time for chaos detection in circuits. The advantages of this method (especially in terms of simulation time) are presented, together with an example of detection of chaotic route to chaos in the case of a chaotic-operating Colpitts oscillator. 相似文献
69.
Evangelos Koustas Eleni-Myrto Trifylli Panagiotis Sarantis Nikolaos Papadopoulos Eleni Karapedi Georgios Aloizos Christos Damaskos Nikolaos Garmpis Anna Garmpi Kostas A. Papavassiliou Michalis V. Karamouzis Athanasios G. Papavassiliou 《International journal of molecular sciences》2022,23(12)
Gastrointestinal (GI) cancer constitutes a highly lethal entity among malignancies in the last decades and is still a major challenge for cancer therapeutic options. Despite the current combinational treatment strategies, including chemotherapy, surgery, radiotherapy, and targeted therapies, the survival rates remain notably low for patients with advanced disease. A better knowledge of the molecular mechanisms that influence tumor progression and the development of optimal therapeutic strategies for GI malignancies are urgently needed. Currently, the development and the assessment of the efficacy of immunotherapeutic agents in GI cancer are in the spotlight of several clinical trials. Thus, several new modalities and combinational treatments with other anti-neoplastic agents have been identified and evaluated for their efficiency in cancer management, including immune checkpoint inhibitors, adoptive cell transfer, chimeric antigen receptor (CAR)-T cell therapy, cancer vaccines, and/or combinations thereof. Understanding the interrelation among the tumor microenvironment, cancer progression, and immune resistance is pivotal for the optimal therapeutic management of all gastrointestinal solid tumors. This review will shed light on the recent advances and future directions of immunotherapy for malignant tumors of the GI system. 相似文献
70.
Terence C. Lau Jianguo Lu John Mylopoulos Kostas Kontogiannis 《Information Systems Frontiers》2003,5(2):149-160
As technology evolves, many organizations face the problem of migrating legacy applications from one technology base to another. We report on a case study involving the migration of legacy code into the IBM® WebSphere® Commerce Suite product. Specifically, we focus on the problem of migrating applications that use traditional database access techniques to applications using the Enterprise JavaBean (EJB) programming model. Our results include a practical methodology that facilitates such migration, as well as a tool that supports this methodology. The tool has been released on IBM's alphaWorks site. 相似文献