Physical and mechanical properties of linear low‐density polyethylene/cycloolefin copolymer/layered silicate nanocomposite

Nanocomposites based on cyclic olefin copolymer/linear low density polyethylene blends (COC/LLDPE) with various contents of three different modified organoclays (20A, 10A, and I28E) compatibilized with polyethylene grafted maleic anhydride (PEgMA) were prepared by met mixing. The influence of content and type of organoclay and compatibilizer on nanocomposite morphology, thermal, and mechanical properties as well as on oxygen and water vapour barrier properties was determined. X‐ray diffraction (XRD) and transmission microscopy (TEM) were used to investigate the clay dispersion, which showed a strong dependence on compatibilizer and type of organoclay. An exfoliated–intercalated morphology was obtained for compatibilized samples of C20A and I28E organoclays at 5 wt%. A less intercalated structure was obtained for samples with C10A. The exfoliated–intercalated structure was influenced both by the compatibilizer and the increase on the nanocomposite viscosity due to the COC incorporation as was determined by Rheological measurements. Mechanical analysis gave an evidence of increasing stiffness after nanoclay was added into COC/LLDPE blend matrix observing higher Young modulus for the compatibilized samples. A notorious decrease of Oxygen and Water vapour permeation rate was observed for COC/LLDPE blend films nanocomposites only when using C20A and I28E clays. These results can be useful in the design of sustainable flexible films for the packaging requirements of specific types of food. POLYM. COMPOS., 37:3167–3174, 2016. © 2015 Society of Plastics Engineers     

Estimating the Rank of the Spectral Density Matrix

Abstract. The rank of the spectral density matrix conveys relevant information in a variety of statistical modelling scenarios. This note shows how to estimate the rank of the spectral density matrix at any given frequency. The method presented is valid for any hermitian positive definite matrix estimate that has a normal asymptotic distribution with a covariance matrix the rank of which is known.     

Analytical and experimental verification of substrate noise spectrum for mixed-signal ICs

In this paper, the most relevant characteristics of the substrate noise spectrum for mixed-signal integrated circuits (ICs) are derived using a simple analytical model. These characteristics are related to parameters of the digital circuit, the package + printed circuit board parasitics, and other elements of the mixed-signal IC. The model used to derive the substrate noise spectral characteristics includes the statistical properties of the digital switching current waveform and the coupling transfer function between the digital power supply nodes and the substrate node of the victim circuitry. The results of the work are validated experimentally on a mixed-signal prototype.     

Interdose interval effects on the development of contextual tolerance to nicotine's analgesic effects in rats (Rattus norvegicus).

Learning models of associative and nonassociative drug tolerance predict that the development of contextual tolerance to drug effects is disrupted when the drug is delivered at short interdose intervals (IDIs). The authors examined the impact of 1 long IDI and 2 short IDIs in the development of contextual nicotine tolerance. Associative tolerance was investigated by giving rats (Rattus norvegicus) 10 subcutaneous injections of nicotine at either long (72-hr) IDIs or short (6-hr and 4.5-hr) IDIs. The delivery of nicotine was either explicitly paired or explicitly unpaired with a distinctive context. A 3rd group of rats was exposed to the experimental procedures but received only saline. Associative tolerance to nicotine's analgesic effects was defined as a shift to the right of the dose-response curve (DRC) of rats in the explicitly paired condition with respect to the DRC of rats in the explicitly unpaired condition. Analgesia was assessed with the tail-flick and hot-plate devices. In the tail-flick assessment, associative tolerance was evident in the 72-hr and the 6-hr IDI conditions only. In the hot-plate assessment, associative tolerance was present in the 72-hr IDI condition only. The findings suggest that contextual tolerance to nicotine's analgesic effects are positively related to IDI length and are more readily demonstrated with the tail-flick method than with the hot-plate method. Overall, the results supported the thesis that nicotine tolerances that develop to different IDIs are qualitatively different and may be mediated by different psychological and physiological mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scaling laws as a tool of materials informatics

This paper discusses the utility of scaling laws to materials informatics and presents the algorithm Scaling LAW (SLAW), useful to obtain scaling laws from statistical data. These laws can be used to extrapolate known materials property data to untested materials by using other more readily available information. This technique is independent of a characteristic length or time scale, so it is useful for a broad diversity of problems. In some cases, SLAW can reproduce the mathematical expression that would have been obtained through an analytical treatment of the problem. This technique was originally designed for mining statistical data in materials processing and materials behavior at a system level, and it shows promise for the study of the relationship between structure and properties in materials.     

Methodology for inventorying greenhouse gas emissions from global cities

This paper describes the methodology and data used to determine greenhouse gas (GHG) emissions attributable to ten cities or city-regions: Los Angeles County, Denver City and County, Greater Toronto, New York City, Greater London, Geneva Canton, Greater Prague, Barcelona, Cape Town and Bangkok. Equations for determining emissions are developed for contributions from: electricity; heating and industrial fuels; ground transportation fuels; air and marine fuels; industrial processes; and waste. Gasoline consumption is estimated using three approaches: from local fuel sales; by scaling from regional fuel sales; and from counts of vehicle kilometres travelled. A simplified version of an intergovernmental panel on climate change (IPCC) method for estimating the GHG emissions from landfill waste is applied. Three measures of overall emissions are suggested: (i) actual emissions within the boundary of the city; (ii) single process emissions (from a life-cycle perspective) associated with the city's metabolism; and (iii) life-cycle emissions associated with the city's metabolism. The results and analysis of the study will be published in a second paper.     

Diagnostic value of a miracidium in urinary sediment

The Medical School of the Ljubljana University has a long lasting tradition in teaching the history of medicine. Since 1934, all students of medicine and dentistry in Slovenia have attended the courses in history of medicine which were and still are mandatory. The first years of lectures on the history of medicine at the Ljubljana University Medical School coincided with the struggle for the establishment and recognition of a full medical curriculum in Slovenia. Dr Ivan Pintar (1888-1963), the first lecturer of the history of medicine (1934-1963), was a man of great ethical and national values and an ardent advocate for the promotion of Slovene contribution to medical culture in Slovenia, former Yugoslavia, and Europe. Pintar's concept of history of medicine included general historical, sociological, ethical, cultural, psychological, biotechnical, and other aspects. During 30 years of his endeavors, he did a pioneer work in the research on the history of medicine in Slovenia. For many years he was the editor of the Medical Chamber Bulletin, chairman of the Slovene Medical Society, and the founder of the Section for the History of Medicine in 1951. He wrote the first Slovene textbook on the history of medicine and published many articles on prominent physicians from Slovenia. He paved the way for the new generation of medical historians in Slovenia. Owing to him, contemporary Slovene physicians and dentists are aware of the importance of professional tradition. They know how to use the past experiences for new achievements.     

Detection of Plagiarism in Programming Assignments

Laboratory work assignments are very important for computer science learning. Over the last 12 years many students have been involved in solving such assignments in the authors' department, having reached a figure of more than 400 students doing the same assignment in the same year. This number of students has required teachers to pay special attention to conceivable plagiarism cases. A plagiarism detection tool has been developed as part of a full toolset for helping in the management of the laboratory work assignments. This tool defines and uses four similarity criteria to measure how similar two assignment implementations are. The paper describes the plagiarism detection tool and the experience of using it over the last 12 years in four different programming assignments, from microprogramming a CPU to system programming in C.