The direct exposure of volatile organic compounds (VOCs) is widely related to several adverse health effects. Therefore, an accurate amount of its usage is necessary required depending on the ...threshold limit. There have been a variety of sensors developed to measure an amount of VOC for safety use. Optical fiber-based VOC sensors offer huge advancements in technologies to overcome several limitations from the convectional VOC sensors that appeared over the past decade. Real-time monitoring and detection of VOCs are important to maintain a safe and healthy domestic/industrial environment. The optical fibers are highly-sensitive and widely applied to several ranges of parameters including gas sensing, and have also been used to monitor VOCs at the sub-ppm range. Recognizing the major developments in the field of the optical fiber, this article aims to review the recent progress in VOC monitoring, resulting in a wide range of sensing configurations are being discussed. Additionally, the article highlights the advantages, limitations, and future possibilities in this area.
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The efficient (site-specific) management of soil nutrients is possible by understanding the spatial variability in distribution of phyto-available nutrients (here after called available nutrients) ...and identifying the soil management zones (MZs) of agricultural landscapes. There is need for delineating soil MZs of agricultural landscapes of the world for efficient management of soil nutrients in order to obtain sustainability in crop yield. The present study was, therefore, undertaken to understand the spatial distribution pattern of available micronutrients (zinc (Zn), boron (B), iron (Fe), manganese (Mn) and copper (Cu)), available sulphur (S), and soil properties (soil acidity (pH), electrical conductivity (EC) and organic carbon (SOC) content) in soils of intensively cultivated Indo-Gangetic Plain (IGP) of India and to delineate soil MZs for efficient management of soil nutrients. Totally, 55101 soil samples from 0-15 cm depth were obtained from 167 districts of IGP during 2014 to 2017 and were analysed for different soil parameters. Soil pH, EC and SOC content varied from 4.44 to 9.80, 0.02 to 2.13 dS m.sup.-1 and 0.10 to 1.99%, respectively. The concentration of available Zn, B, Fe, Mn, Cu and S varied from 0.01 to 3.27, 0.01 to 3.51, 0.19 to 55.7, 0.05 to 49.0, 0.01 to 5.29 and 1.01 to 108 mg kg.sup.-1, respectively. Geostatistical analysis resulted in varied distribution pattern of studied soil parameters with moderate to strong spatial dependence. The extent (% area) of nutrient deficiencies in IGP followed the order: S > Zn > B > Mn > Cu > Fe. Principal component analysis and fuzzy c-means clustering produced six distinctly different soil MZs of IGP for implementation of zone-specific soil nutrient management strategies for attaining sustainability in crop yield. The developed MZ maps could also be utilized for prioritization and rationalization of nutrients supply in IGP of India.
Replacement of Dy and substitution of Nd in NdFeB‐based permanent magnets by Ce, the most abundant and lowest cost rare earth element, is important because Dy and Nd are costly and critical rare ...earth elements. The Ce, Co co‐doped alloys have excellent high‐temperature magnetic properties with an intrinsic coercivity being the highest known for T ≥ 453 K.
Abstract
We present experimental results of the trace argon impurity puffing in the ohmic plasmas of Aditya-U tokamak performed to study the argon transport behaviour. Argon line emissions in visible ...and Vacuum Ultra Violet (VUV) spectral ranges arising from the plasma edge and core respectively are measured simultaneously. During the experiments, space resolved brightness profile of Ar
1+
line emissions at 472.69 nm (3p
4
4s
2
P
3/2
–3p
4
4p
2
D
3/2
), 473.59 nm (3p
4
4s
4
P
5/2
–3p
4
4p
4
P
3/2
), 476.49 nm (3p
4
4s
2
P
1/2
–3p
4
4p
2
P
3/2
), 480.60 nm (3p
4
4s
4
P
5/2
–3p
4
4p
4
P
5/2
) are recorded using a high resolution visible spectrometer. Also, a VUV spectrometer has been used to simultaneously observe Ar
13+
line emission at 18.79 nm (2s
2
2p
2
P
3/2
–2s2p
2
2
P
3/2
) and Ar
14+
line emission at 22.11 nm (2s
2
1
S
0
–2s2p
1
P
1
). The diffusivity and convective velocity of Ar are obtained by comparing the measured radial emissivity profile of Ar
1+
emission and the line intensity ratio of Ar
13+
and Ar
14+
ions, with those simulated using the impurity transport code, STRAHL. Argon diffusivities ~ 12 m
2
/s and ~ 0.3 m
2
/s have been observed in the edge (ρ > 0.85) and core region of the Aditya-U, respectively. The diffusivity values both in the edge and core region are found to be higher than the neo-classical values suggesting that the argon impurity transport is mainly anomalous in the Aditya-U tokamak. Also, an inward pinch of ~ 10 m/s mainly driven by Ware pinch is required to match the measured and simulated data. The measured peaked profile of Ar density suggests impurity accumulation in these discharges.
2-Azetidinone, a β-lactam four member heterocyclic compound involved in research aimed to evaluate new products that possess interesting biological activities. These compounds reported for their ...antimicrobial and antifungal activities. Successful introduction of aztreonam as a potent inhibitor of cephalosporinase and ezetimibe as a cholesterol absorption inhibitor proved potential of 2-azetidinone moiety. Subsequently 2-azetidinones were highlighted as a potent mechanism based inhibitor of several enzymes like human tryptase, chymase, thrombin, leukocyte elastase, human cytomegalovirus protease and serine protease enzyme. These derivatives also known to possess antitubercular, anti-inflammatory, antitumor, anti-HIV, antiparkinsonian, antidiabetic and vasopressin V1a antagonist activity. The present review article focuses on the pharmacological profile of 2-azetidinones with their potential activities.
2-Azetidinone and their derivatives occupy a central place in medicinal chemistry due to their diverse and broad pharmacological profile. This article focuses on the various pharmacological profile of 2-azetidinone scaffold and development of novel derivatives with their potential activity.
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First-order magnetic transitions (FOMTs) with a large discontinuity in magnetization are highly sought in the development of advanced functional magnetic materials. Isosymmetric magnetoelastic FOMTs ...that do not perturb crystal symmetry are especially rare, and only a handful of material families, almost exclusively transition metal-based, are known to exhibit them. Yet, here we report a surprising isosymmetric FOMT in a rare-earth intermetallic, Eu
In. What makes this transition in Eu
In even more remarkable is that it is associated with a large latent heat and an exceptionally high magnetocaloric effect in low magnetic fields, but with tiny lattice discontinuities and negligible hysteresis. An active role of the Eu-5d and In-4p states and a rather unique electronic structure borne by In to Eu charge transfer, altogether result in an unusual exchange mechanism that both sets the transition in motion and unveils an approach toward developing specific magnetic functionalities ad libitum.
In the present paper, a new kind of concave shaped refractive index sensor (CSRIS) exploiting localized surface plasmon resonance (LSPR) is proposed and numerically optimized. The LSPR effect between ...polaritons and the core guided mode of designed CSRIS is used to enhance the sensing performance. The sensor is characterized for two types of sensing structures coated with gold (Au) film and Au nanowires (AuNWs), respectively. The influence of structural parameters such as the distance (D) of the concave shaped channel (CSC) from the core, the diameter of the nanowire (dn) and the size (s) of the CSC are investigated here. In comparison to Au film, the AuNWs are shown to significantly enhance the sensitivity and the performance of the designed sensor. An enhanced sensitivity of 4471 nm/RIU (refractive index unit) is obtained with AuNWs, for a wide range of analytes refractive index (na) varying between 1.33 to 1.38. However, for conventional Au film; the sensitivity of 808.57 nm/RIU is obtained for the same range of analytes.
•The performance of evacuated tube collector with/without storage was investigated.•Evacuated tube collector with phase change material showed better performance.•Designed system is suitable for ...day/night time utilization of hot water.•Thermal cycle test of SA-67 has been studied for long term stability.
This manuscript presents an experimental investigation of heat pipe evacuated tube solar collector with and without phase change material for water heating application under the same weather conditions. In this study, a comparative analysis of two systems has been done in the same weather condition. Where evacuated tubes of the first system (evacuated tube collector-A) were left without phase change material and second system (evacuated tube collector-B) was integrated with SA-67 as phase change material. In order to ensure the thermal and chemical stability of the selected phase change material, thermal cycling treatment was carried out. The results showed that SA-67 has excellent chemical and thermal stability even after 1500 thermal cycling treatment.
In order to analyze the thermal performance of the designed systems, the experiment was conducted with five different water flow rates (8, 12, 16, 20 and 24 L per hour). The daily thermal efficiency of evacuated tube solar collector with and without phase change material was varied in the range of 42–55% and 79–87% respectively. Although, the daily energy efficiency of evacuated tube collector integrated with phase change material was 37.56%, 35.31%, 36.69%, 32.34%, and 32.73% higher than evacuated tube collector without phase change material for water flow rates of 8, 12, 16, 20 and 24 L per hour respectively. The daily thermal efficiency for both systems was maximum at the flow rate of 20 L per hour. The heat transfer parameters for the designed systems have also been evaluated and compared.
Magnetic properties of Ce and Co co-doped (Nd1-xCex)2Fe14-yCoyB compounds have been investigated both in bulk polycrystalline and rapidly solidified nanostructured ribbon forms. For certain Ce ...concentrations the materials exhibit spin re-orientation transitions below 140 K. The Curie temperatures, saturation magnetizations, and other magnetic properties relevant for applications as permanent magnets are controlled by Ce and Co substitutions for Nd and Fe, respectively. Most importantly, the results show that Ce, Co co-doped compounds are excellent replacements for several Dy-based high performance permanent magnets (dysprosium is one of the critical elements and is, therefore, in short supply). The high temperature (>375 K) magnetic properties for Nd–Ce–Fe–Co–B based alloys show promise not only as a replacement for Dy-doped Nd2Fe14B permanent magnets, but the new alloys also require significantly lower amounts of Nd, which too is the critical element that can be replaced by a more abundant Ce.
Transmission electron microscopy (TEM) micrographs of the free side (a), the wheel side (b) of (Nd0.8Ce0.2)2Fe14B melt spun ribbon. (c) Maximum energy product, (BH)max, as functions of temperature for melt spun ribbons of Nd2Fe14B, (Nd0.8Ce0.2)2Fe14B and (Nd0.8Ce0.2)2Fe14Co2B. Display omitted
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