This paper presents a critical review of advancements made in the area of non-contact angle sensing in the last two decades. Angular position sensing is an essential function in most of the ...engineering systems associated with industries such as automotive, robotics, process, and aircraft. The review shows significant progress that has been achieved in the performance aspects of angle sensors, overcoming the challenges introduced by new and specific applications. Progress is also visible in effectively utilizing the emerging allied technologies on the sensing and electronics field for the development of high-end angle sensors. As a part of the review, the important sensing techniques utilized for the angle sensors are identified and carefully looked at the advantages and limitations of those. Besides, the potential areas for improvements are also suggested. The important techniques employed to design and develop the angle sensors are based on capacitive, inductive, magneto-resistive, and optical schemes. Signal conditioning circuits, analog or digital, or a combination of it, are necessary to derive the best from the sensing elements. They play a vital role in the overall performance of the sensor. The review addresses the advancement in the sensing element, methodology, and signal conditioning aspect in detail. In this review, the important angle sensors reported are evaluated against the performance parameters such as range, resolution, linearity, accuracy, sensitivity, power consumption, complexity, cost, manufacturability, and reliability.
Fossil fuels endow wide applications in industrial, transportation, and power generation sectors. However, smoke released by burning fossil fuels contains toxic gases, which pollutes the environment ...and severely affects human health. Carbon nanotubes (CNTs) are potential material for gas sensors due to their high structural porosity and high specific surface area. Defects present on the CNT sidewalls and end caps facilitate adsorption of gas molecules. The chemical procedures adopted to purify and disperse carbon nanotubes create various chemical groups on their surface, which further enhance the adsorption of gas molecules and thus improve the sensitivity of CNTs. Present review focuses on CNT chemiresistive gas sensing mechanisms, which make them suitable for the development of next generation sensor technology. The resistance of carbon nanotubes decreases when oxidizing gas molecules adsorb on their surface, whereas, adsorption of reducing gas molecules results in increasing the resistance of CNTs. Sensing ability of carbon nanotubes for the gases namely, NO, NO2, CO, CO2 and SO2, released on burning of fossil fuels is reviewed. This review provides basic understanding of sensing mechanisms, creation of adsorption sites by chemical processes and charge transfer between adsorbed gas molecules and surface of CNTs. In addition, useful current update on research and development of CNT gas sensors is provided.
Current efforts of recent implant technology have been aimed principally at the improvement of corrosion resistance and biocompatibility. The present study demonstrates that the electro ...polymerisation of pyrrole and incorporation of zirconia (ZrO2) nanoparticles can be successfully combined to produce bioactive polypyrrole nanocomposite coatings for orthopaedic implants. Polypyrrole/ZrO2 nanocomposite coatings were electrochemically synthesised by cyclic votametric technique on 316L stainless steel (SS) in aqueous solution of oxalic acid. The existence of ZrO2 nanoparticles in polypyrrole (PPy) matrix was confirmed by Fourier Transform Infrared (FT-IR) spectroscopy and X ray diffraction (XRD) analysis. The surface morphology of coated 316L SS substrates was observed using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). Micro hardness of coated 316L SS was examined using Vickers hardness method. The electrochemical studies were carried out using cyclic polarisation and electrochemical impedance spectroscopy (EIS) measurements. In order to describe the biocompatibility, contact angle measurements and in vitro characterisation were carried out in simulated body fluid (SBF) solution. The results showed that the nanocomposite coatings exhibit superior biocompatibility and enhanced corrosion protection performance over 316L SS due to their hydrophilic, smooth, compact and less porous surface morphology than that of pure polypyrrole coatings.
► Effect of nanoZrO2 on the corrosion protection of PPy coated 316L SS was evaluated. ► Compact, well adherent and smooth surface morphology was achieved for PPy/ZrO2. ► Mechanical properties and wettability of PPy/ZrO2 coatings were more enhanced than those of PPy. ► Nano ZrO2 in PPy matrix enhanced the corrosion protection performance in SBF. ► Incorporation of nanoZrO2 improved biocompatibility of coated 316L SS in SBF.
Innovative techniques have been proposed to overcome the challenge of the strong tendency of brittle materials to crack during machining. One of them is the use of an epoxy coating to serve as a ...crack formation restraint. However, this only serves to achieve ductile-mode grinding along the uncut shoulders. Therefore, this study evaluates the effect of a layer of epoxy resin on the machined surface perpendicular to the micro-cutting direction of a brittle material, single-crystal calcium fluoride. An increase in the ductile–brittle transition was observed in micro-cutting experiments on the (111) plane of calcium fluoride with the use of a 4-μm thick epoxy resin coating, ranging from 167–347 nm to 213–476 nm for the 0° rake angled tool. A similar increase was also observed with the +5° rake angle, ranging from 91–233 nm to 187–310 nm. An energy-based ductile–brittle transition predictive model is introduced, which characterises the anisotropic behaviour of the single crystal and incorporates the additional stress induced during cutting with a coating as a fraction of the coating hardness. The analytical model accurately predicts a consistent range of improvement from 69–325 nm to 257–485 nm for the 0° rake angle and from 62–285 nm to 215–460 nm for the +5° rake angle. The ductile-mode cutting energy increases to preserve its dominance over brittle-mode cutting and delays the onset of brittle-mode activation. The validity of the model extends the understanding of a surface coating as a restraining technology to include the beneficial stress acting in the deformation zone during cutting.
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•Epoxy resin coating can enhance ductile-mode cutting of CaF2 single-crystal.•Ductile–brittle transitions increase by at least 27.5 % with epoxy coating.•An anisotropic ductile–brittle transition predictive model is proposed.•The coating increases ductile-mode energy dominance to improve machinability.•Additional stress induced in the workpiece is a function of coating hardness.
Zinc oxide nanoparticles are well-known metal oxide nanoparticles having numbers of applications in the field of cosmetology, medicine, and chemistry. However, the number of reports has indicated its ...toxicity also such as hepatotoxicity, pulmonary toxicity, neurotoxicity, and immunotoxicity. Thus, in this article, we have analyzed the potential risks and benefits of zinc oxide nanoparticles. The data related to risks and benefits of zinc oxide nanoparticles have been extracted from PubMed (from January 2007 to August 2019). A total of 3,892 studies have been published during this period regarding zinc oxide nanoparticles. On the basis of inclusion and exclusion criteria, 277 studies have been included for the analysis of risks and benefits. Emerging reports have indicated both risks and benefits of zinc oxide nanoparticles in concentration- and time-dependent manner under in vitro and in vivo conditions through different mechanism of action. In conclusion, zinc oxide nanoparticles could play a beneficial role in the treatment of various diseases but safety of these particles at particular effective concentration should be thoroughly evaluated.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Radioiodine is one of the long-lived fission products and also an important radionuclide released during nuclear accidents, which generates interest in its environmental fate. Its sorption has been ...studied in a wide range of materials, but no equivalent study exists for microplastics, an emerging environmental vector. Weathering and biofilm formation on microplastics can enhance radioiodine sorption. For the first time, we're reporting how radioiodine interacts with different types of polyethylene derived microplastics (pristine, irradiated, and biofilm developed microplastics). This study revealed that exposure to radiation and the marine environment significantly alters the physico-chemical properties of microplastics. In particular, in marine-exposed samples, a signature of biofilm development was detected. Speciation study indicates that iodine exists in the iodide form in the studied marine environment. The study revealed that, iodide ions attach to biofilm-developed microplastics via electrostatic, ion-dipole, pore filling, and van der Waals interactions. Pore filling, ion-dipole, and van der Waals interactions may cause iodide binding to irradiated microplastics, whereas pore-filling and van der Waals interactions cause iodide binding to pristine microplastics. The distribution coefficient (Kd) of iodine on microplastics is positively correlated with biofilm biomass, which signifies the role of biofilm in radioiodine uptake. The Kd indicates microplastics are potential iodide accumulators and could be a possible vector in the marine system.
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•Weathering and biofilm growth alter the microplastics surface in the marine system.•Radioiodine is measurably sorbed onto microplastics + biofilm.•Sorption of radioiodine by biofilm mainly controlled by electrostatic interaction.•Sorption on Marine exposed HDPE is higher than LDPE due to higher biofilm biomass.
Insulin resistance is a determining factor in the pathophysiology of type 2 diabetes mellitus (T2DM). Exercise is known to improve insulin resistance, but a systematic review of the literature is ...lacking.
This systematic review and meta-analysis focused on identifying evidence for the effectiveness of a structured exercise intervention program for insulin resistance in T2DM.
We searched MEDLINE via PubMed, CINHAL, Scopus and Web of Science, and the Cochrane Central Register of Controlled Trials for reports of studies on fasting insulin, homeostatic model assessment for insulin resistance (Homa-IR), fasting blood sugar, glycated hemoglobin and body mass index in patients with T2DM and healthy controls that were published between 1990 and 2017. Data are reported as the standardized mean difference or mean difference with 95% confidence intervals (CIs).
Among 2242 records retrieved, only 11 full-text articles were available for meta-analysis. Data for 846 participants were analyzed, 440 in the intervention group, and 406 in the control group. The mean difference for fasting insulin level was−1.64 (95% CI; −3.38 to 0.10), Homa-Ir 0.14 (−1.48 to 1.76), fasting blood sugar−5.12 (−7.78 to−2.45), hemoglobin A1c 0.63 (−0.82 to 2.08) and body mass index−0.36 (−1.51 to 0.79).
The evidence highlights the effectiveness of a structured exercise intervention program for insulin resistance in T2DM with a moderate level 2 of evidence.
This open access volume discloses rich set of findings and policy recommendations for India towards achieving the SDG 2.1 target of zero hunger by 2030. Through its fourteen chapters, it takes an ...integrated approach by examining diverse aspects of food and nutrition security through multidisciplinary lens of Agricultural Economics, Nutrition, Crop Sciences, Anthropology and Law, while being rooted in economics. The chapters reflect this diversity in disciplines in terms of the questions posed, the data sets used, and the methodologies followed. Starting from the evolution of policy response for hunger and nutrition security, the book covers aspects such gender budgeting, dietary diversity, women’s empowerment, calorie intake norms, socio-legal aspects of right to health, subjective wellbeing, bio-fortification, crop insurance and food security linkages, interdependence of public distribution system (for food security) and employment guarantee schemes especially during COVID-19 pandemic, effects of dairy dietary supplements, and so on. With its rich discussions, the book is compelling for students, researchers, policy makers, development professionals and practitioners working in areas of food and nutrition security, SDGs, in particular SDG1, SDG2 and SDG5, and sustainable food systems.
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