scholarly journals Transport of engineered nanoparticles in soils and aquifers

2019 ◽  
Vol 27 (1) ◽  
pp. 43-70 ◽  
Author(s):  
Mahmood Fazeli Sangani ◽  
Gary Owens ◽  
Amir Fotovat

Transport and deposition behaviour of engineered nanoparticles (ENPs) in natural aquifers and soil systems is a key determinant of the fate of these materials in environmental systems. A growing number of experimental studies are being conducted worldwide to address transport and deposition of ENPs in porous media (PM). Here we comprehensively review the main mechanisms and factors affecting the mobility of the environmentally important ENPs in natural PM. A variety of different processes including those that promote mobility and result in elution from the PM and those that hinder their mobility and promote ENP retention can influence ENP’s mobility through soil and aquifer media. The most important contributing factors regarding ENP transport in PM include: the physicochemical properties of the ENP, the media, the hydrodynamics of the system, and the background solution characteristics. Results from several studies conducted on the most common and environmentally important ENPs have shown that under natural environmental conditions, different types of ENPs show different transport behaviour in soil and aquifer systems. Additionally, the importance of media matrix and mobile solution factors in governing mobility of ENPs varies from one type of ENP to another.

The results of experimental studies on the assessment of seismic resistance of various structural solutions of hinged facade systems with a facing layer of brickwork under the action of dynamic loads on the structure, simulating seismic effects in earthquakes of 7-9 points on the scale of MSK-64 are presented. Dynamic tests were carried out with the use of an installation developed at Moscow State University of Civil Engineering, which included a metal stand with special movable supports, hydraulic cylinders (Actuator) and modern measuring equipment. This equipment made it possible to evaluate during testing the force effects on the stand, accelerations, displacements and deformations in any element of the stand and the hinged facade system. Two design variants of the hinged facade system, in which different types of masonry fastening to the supporting substructures are applied, are considered. The factors affecting the seismic stability of the facing layer under the action of dynamic loads and excluding its destruction and the appearance of cracks in it are established. During the tests, accelerations and deformations of the structures of the hinged facade system at the specified points were obtained. On the example of the analysis of the results of experimental dynamic studies of the system of the ATS-450 type of "U-kon" Company of, the effectiveness of the use of special measures that ensure the monolithic masonry and, accordingly, its reliability under seismic influences is shown.


2020 ◽  
Vol 47 (2) ◽  
pp. 392-401
Author(s):  
T. R. Birkhead ◽  
G. Axon ◽  
J. R. Middleton

Most of the approximately 75 known eggs of the extinct great auk ( Pinguinus impennis) are in public museums, with a few in private collections. A small number of these eggs has sustained damage, either at the time of collection or subsequently, and two of these eggs are known to have been repaired. The two eggs suffered rather different types of damage and were subsequently restored using different techniques. The first, known as Bourman Labrey's egg, sustained extensive damage sometime prior to the 1840s, when the shell was broken into numerous pieces. This egg was repaired by William Yarrell in the 1840s, and when it was restored again in 2018, it was discovered that Yarrell's restoration had involved the use of an elaborate cardboard armature. This egg is currently in a private collection. The second egg, known as the Scarborough egg, bequeathed to the Scarborough Museum in 1877, was damaged (by unknown causes) and repaired, probably by the then curator at Scarborough, W. J. Clarke, in 1906. This egg was damaged when one or more pieces were broken adjacent to the blowhole at the narrow end (where there was some pre-existing damage). The media reports at the time exaggerated the extent of the damage, suggesting that the egg was broken almost in two. Possible reasons for this exaggeration are discussed. Recent examination using a black light and ultraviolet (UV) revealed that the eggshell had once borne the words, “a Penguin's Egg”, that were subsequently removed by scraping.


Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.


2020 ◽  
pp. 97-110
Author(s):  
E. N. Mikhailova ◽  
V. A. Telegina

The article is devoted to the study of evaluative tools used in modern French media in order to form the media image of a representative of the political elite. The techniques used in the creation of a memorial media portrait of Jacques Chirac (1932—2019), President of France from 1995 to 2007 are considered. The research material was the most prestigious French print media of various political orientations, published in late September — early October 2019 in connection with the death of the ex-President of the French Republic. The relevance of the research topic is dictated by the close attention of modern linguistics to axiological phenomena, differently presented in different types of discursive practices. The novelty of the study is due to the appeal to the analysis of the complex of evaluation tools used in the French print media when characterizing the former leader of the state during the nation’s farewell period. The estimated potential of the title of the article and its influence on the formation of the estimated vector of the entire text of the publication are shown. A systematic analysis of the assessment expression means, reflected in the memorial media portrait of the politician, is given. The factors that influenced the peculiarities of their use in this type of media portrait are revealed.


Author(s):  
Б.И. Гельцер ◽  
Э.В. Слабенко ◽  
Ю.В. Заяц ◽  
В.Н. Котельников

Одним из основных требований к разработке экспериментальных моделей цереброваскулярных заболеваний является их максимальная приближенность к реальной клинической практике. В работе систематизированы данные по основным методам моделирования острой ишемии головного мозга (ОИГМ), представлена их классификация, анализируются данные о преимуществах и недостатках той или иной модели. Обсуждаются результаты экспериментальных исследований по изучению патогенеза ОИГМ с использованием различных моделей (полной и неполной глобальной, локальной и мультифокальной ишемии) и способов их реализации (перевязка артерий, клипирование, коагуляция, эмболизация и др.). Особое внимание уделяется «стабильности» последствий острого нарушения мозгового кровообращения: необратимых ишемических повреждений головного мозга или обратимых с реперфузией заданной продолжительности. Отмечается, что важное значение в этих исследованиях должно принадлежать современным методам прижизненной визуализации очагов острого ишемического повреждения, что позволяет оценивать динамику патологического процесса. Предлагаемый метод отвечает требованиям гуманного обращения с животными. Подчеркивается, что выбор релевантной модели ОИГМ определяется задачами предстоящего исследования и технологическими ресурсами научной лаборатории. Development of experimental models for acute forms of cerebrovascular diseases is essential for implementation of methods for their prevention and treatment. One of the principal requirements to such models is their maximum approximation to actual clinical practice. This review systematized major models of acute cerebral ischemia (ACI), their classification, and presented information about their advantages and shortcomings. Also, the review presented results of experimental studies on pathophysiological mechanisms of different types of modeled ACI (complete and incomplete global, local, and multifocal ischemia) and methods for creating these models (arterial ligation, clipping, coagulation, embolization, etc.). Particular attention was paid to “stability” of the consequences of acutely impaired cerebral circulation - an irreversible ischemic brain injury or a reversible injury with reperfusion of a given duration. The authors emphasized that in such studies, a special significance should be given to intravital imaging of acute ischemic damage foci using modern methods, which allow assessing the dynamics of the pathological process and meet the requirements to humane treatment of animals. The choice of a relevant ACI model is determined by objectives of the planned study and the technological resources available at the research laboratory.


Author(s):  
E.O. Chernova

The article gives an analysis of the results of authorial experimental studies. Motivational factors affecting adolescents' participation in criminal groups are considered, they are: dominant groups of motives, the predominance of aspiration to success or avoidance of failures. Thus, the author explores the subjective potential of the personality of adolescent groupers. According to the results of the research, the author concludes that the specificity of the motivation of such adolescents consists in the predominance of material motives, social motives (involvement in social communities, groupings) and motives of recognition and respect. The author notes that the motivation for avoiding failures is more characteristic of such adolescents than the motivation for the pursuit of success. It is concluded that the data obtained can serve as a basis for developing preventive measures when working with adolescents at risk.


Author(s):  
E. M. Ratnikov ◽  
D. O. Milko

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.


2021 ◽  
pp. 174804852199056
Author(s):  
Baruch Shomron ◽  
Amit Schejter

This study examines how media representations of Palestinian-Israeli politicians, can help community members realize their capabilities. The study’s database is comprised of 1,207 interviews conducted with Palestinian-Israeli politicians on news and current affairs programs on the three national television channels and the two national radio stations in Israel, for 24 months (2016-2017). We identified and analyzed the differences in the modes of representation between national and local Palestinian-Israeli politicians and between Palestinian-Israeli parliament members in the Joint List and Palestinian-Israeli parliament members in Zionist parties, all through the capabilities prism. In this study, we demonstrated how different types of Palestinian-Israeli politicians may potentially affect the realization of different political functions and capabilities. Analyzing political representations in the media through the theoretical framework of the ‘capabilities approach’ contributes to a more comprehensive insight into the roles the media can play promoting people’s wellbeing and human rights, relative to traditional media theories.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masako Tachibana ◽  
Toshiya Inada ◽  
Masaru Ichida ◽  
Norio Ozaki

AbstractDelirium develops through a multifactorial process and include multiple subtypes with different pathological factors. To refine the treatment and care for delirium, a more detailed examination of these subtypes is needed. Therefore, this study aimed to explore the factors affecting delirium in cases in which hallucinations are conspicuous. In total, 602 delirium cases referred to the psychiatry department at a general hospital between May 2015 and August 2020 were enrolled. The Delirium Rating Scale-revised-98 was used to assess perceptual disturbances and hallucinations in patients with delirium. Multiple regression analysis was applied to determine whether individual factors were associated with the hallucinations. A total of 156 patients with delirium (25.9%) experienced hallucinations, with visual hallucinations being the most common subtype. Alcohol drinking (p < 0.0005), benzodiazepine withdrawal (p = 0.004), and the use of angiotensin II receptor blockers (p = 0.007) or dopamine receptor agonists (p = 0.014) were found to be significantly associated with hallucinations in patients with delirium. The four factors detected in this study could all be reversible contributing factors derived from the use of or withdrawal from exogenous substances.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2506
Author(s):  
Wamidh H. Talib ◽  
Ahmad Riyad Alsayed ◽  
Alaa Abuawad ◽  
Safa Daoud ◽  
Asma Ismail Mahmod

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.


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