Performance analysis of LoRa in the 2.4 GHz ISM band: coexistence issues with Wi-Fi

Telecommunication Systems - Within realization of the visions of the Internet-of-Things (IoT), Low Power Wide Area Networks (LPWANs) are undoubtedly one of the fields that attract high interest...     

Activity of ruthenium hydrogenation catalysts in copper(II) formate decomposition

Charcoal-, silica-, alumina- and titanium(IV) oxide-supported ruthenium catalysts, prepared by conventional impregnation and incipient wetness methods from a ruthenium(III) oxide precursor were tested in copper(II) formate decomposition in aqueous solution. Such a reaction was found to be an efficient and simple activity test of charcoal-supported catalysts. The application of this reaction for a bimetallic ruthenium–copper catalyst preparation was also suggested. Experimental results were compared with those obtained using commercial catalysts and ruthenium black.     

Utility of silver‐coated fabrics as electrodes in electrotherapy applications

The present study deals with the deposition of silver particles onto knitted fabrics for possible applications in electrotherapy. The performance of silver‐coated fabrics was evaluated based on number of properties such as electrical conductivity, physiological comfort, antibacterial, and durability. Furthermore, the conductive fabrics were subjected to various repeated extensions and change in electrical resistivity was examined to simulate the performance of electrodes under various movements of human body. With increase in extension till 80%, very small change in volume electrical resistance was observed and after 90% extension, the electrical resistance was found to increase significantly. The volume resistance was found to remain constant for repeated extensions of over 100 cycles and also there was insignificant change in electrical resistivity when constant current was applied over prolonged time. The utility of silver‐coated fabrics can be expected as flexible textile electrodes in transcutaneous electrical nerve stimulation electrotherapy applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46357.     

Accurate micro-computed tomography imaging of pore spaces in collagen-based scaffold

In this work we have used X-ray micro-computed tomography (μCT) as a method to observe the morphology of 3D porous pure collagen and collagen-composite scaffolds useful in tissue engineering. Two aspects of visualizations were taken into consideration: improvement of the scan and investigation of its sensitivity to the scan parameters. Due to the low material density some parts of collagen scaffolds are invisible in a μCT scan. Therefore, here we present different contrast agents, which increase the contrast of the scanned biopolymeric sample for μCT visualization. The increase of contrast of collagenous scaffolds was performed with ceramic hydroxyapatite microparticles (HAp), silver ions (Ag⁺) and silver nanoparticles (Ag-NPs). Since a relatively small change in imaging parameters (e.g. in 3D volume rendering, threshold value and μCT acquisition conditions) leads to a completely different visualized pattern, we have optimized these parameters to obtain the most realistic picture for visual and qualitative evaluation of the biopolymeric scaffold. Moreover, scaffold images were stereoscopically visualized in order to better see the 3D biopolymer composite scaffold morphology. However, the optimized visualization has some discontinuities in zoomed view, which can be problematic for further analysis of interconnected pores by commonly used numerical methods. Therefore, we applied the locally adaptive method to solve discontinuities issue. The combination of contrast agent and imaging techniques presented in this paper help us to better understand the structure and morphology of the biopolymeric scaffold that is crucial in the design of new biomaterials useful in tissue engineering.     

Operationalising resilience for disaster medicine practitioners: capability development through training,simulation and reflection

Cognition, Technology & Work - Resilience has in recent decades been introduced as a term describing a new perspective within the domains of disaster management and safety management. Several...     

The coloration of polypropylene fibres with acid dyes

Modified polypropylene fibre has been prepared by incorporating a polymeric additive into the polypropylene, followed by melt spinning. Fibres with various additive concentrations were dyed with acid dyes, and the amount of dye adsorbed by the fibre was compared with the concentration of dye sites supplied to the fibre by the additive. A diffusion mechanism of dye molecules through interconnected additive particles to the fibre matrix is proposed. Colour yield was assessed by reflectance spectroscopy and photoacoustic spectroscopy. The latter was shown to be particularly suitable for measuring very dark colours. Photoacoustics can also used to detect ring dyeing of fibres at lower additive concentration.     

The Atlas of Physiology and Pathophysiology: Web-based multimedia enabled interactive simulations

The paper is a presentation of the current state of development for the Atlas of Physiology and Pathophysiology (Atlas). Our main aim is to provide a novel interactive multimedia application that can be used for biomedical education where (a) simulations are combined with tutorials and (b) the presentation layer is simplified while the underlying complexity of the model is retained. The development of the Atlas required the cooperation of many professionals including teachers, system analysts, artists, and programmers. During the design of the Atlas, tools were developed that allow for component-based creation of simulation models, creation of interactive multimedia and their final coordination into a compact unit based on the given design. The Atlas is a freely available online application, which can help to explain the function of individual physiological systems and the causes and symptoms of their disorders.     

Study of Biological Activities and ADMET-Related Properties of Novel Chlorinated N-arylcinnamamides

A series of eighteen 4-chlorocinnamanilides and eighteen 3,4-dichlorocinnamanilides were designed, prepared and characterized. All compounds were evaluated for their activity against gram-positive bacteria and against two mycobacterial strains. Viability on both cancer and primary mammalian cell lines was also assessed. The lipophilicity of the compounds was experimentally determined and correlated together with other physicochemical properties of the prepared derivatives with biological activity. 3,4-Dichlorocinnamanilides showed a broader spectrum of action and higher antibacterial efficacy than 4-chlorocinnamanilides; however, all compounds were more effective or comparable to clinically used drugs (ampicillin, isoniazid, rifampicin). Of the thirty-six compounds, six derivatives showed submicromolar activity against Staphylococcus aureus and clinical isolates of methicillin-resistant S. aureus (MRSA). (2E)-N-[3,5-bis(trifluoromethyl)phenyl]- 3-(4-chlorophenyl)prop-2-enamide was the most potent in series 1. (2E)-N-[3,5-bis(Trifluoromethyl)phenyl]-3-(3,4-dichlorophenyl)prop-2-enamide, (2E)-3-(3,4-dichlorophenyl)-N-[3-(trifluoromethyl)phenyl]prop-2-enamide, (2E)-3-(3,4-dichloro- phenyl)-N-[4-(trifluoromethyl)phenyl]prop-2-enamide and (2E)-3-(3,4-dichlorophenyl)- N-[4-(trifluoromethoxy)phenyl]prop-2-enamide were the most active in series 2 and in addition to activity against S. aureus and MRSA were highly active against Enterococcus faecalis and vancomycin-resistant E. faecalis isolates and against fast-growing Mycobacterium smegmatis and against slow-growing M. marinum, M. tuberculosis non-hazardous test models. In addition, the last three compounds of the above-mentioned showed insignificant cytotoxicity to primary porcine monocyte-derived macrophages.     

基于随机算法的纤维材料过滤特性仿真分析

为分析纤维空气过滤材料的流场演变情况,综合过滤效率及颗粒流动轨迹,基于随机算法建立了纤维空气过滤材料的三维模型,并采用计算流体力学中的欧拉-拉格朗日离散相模型,在雷诺相似准则的基础上研究了微米纤维介质中的气固流动特性。结果表明：入口速度变化对流场压力与速度场分布有明显影响,随着入口速度增大,阻滞区域面积增加,流场空隙处更易形成高速流动与速度漩涡,同时流场整体速度差增大,压力损失与入口速度呈正相关;纤维模型对平均粒径为8～18 mm颗粒的过滤效率较为稳定,均在80.4%～84%,在入口速度为2 m/s工况下,过滤效率与粒径接近正比例关系。     

Empirical evaluation of a calibration chart detector

In this paper, we systematically assess the performance of an automatic calibration chart detector. Through simulation we establish the optimal set of control parameters and the rate of successful detection as a function of pose. We validate the simulation results on real images taken from a camera mounted on a robot arm. The results confirm the utility of such simulation studies. The feedback obtained suggested a number of modifications for the chart detection system, which led to a significant improvement in performance. In particular, the chart design was changed to accommodate wider range and better stability in detection. Received: 16 December 1999 / Accepted: 15 October 2000