Effects of long-term open-field ozone exposure on leaf phenolics of European silver birch (Betula pendula Roth)

The response of phenolic compounds as a result of long-term low open-field ozone exposure was studied in ozone-sensitive and ozone-tolerant clones of European silver birch (Betula pendula Roth). The saplings were exposed to 1.5–1.6 times the ambient (elevated) ozone and ambient air (as control) over three growing seasons from May 1996 until August 1998. Quantification by modified Folin-Ciocalteau assay showed a 16.2% increase in total phenolics in elevated ozone plants as compared to that in controls and a corresponding 9.9% increase of 10 phenolic compounds quantified by HPLC. Five nonflavonoids and five flavonoids showed 8.4% and 11.4% increases, respectively. The phenolic results indicated slightly higher ozone sensitivity of clone 5 as compared to clone 2. The most ozone-responsive phenolic compounds in clone 2 and clone 5 were (+)-catechin (CT), chlorogenic acid (CGA), 5-p-coumaroylquinic acid (5CQA), 3-p-coumaroylquinic acid (3CQA), myricetin galactopyranoside (MG), quercetin-3-O-glucuronopyranoside (QGR), and quercetin-3-O-arabinofuranoside (QA). Increased phenolic content in ozone-exposed plants was related to impaired growth and accelerated leaf senescence, indicated by enhanced autumn leaf yellowing and lower chlorophyll and Mg content. The change in carbon allocation towards defensive phenolics at the expense of growth was greater in the ozone-sensitive clone as compared to tolerant clone.     

Dynamic machine learning-based heuristic energy optimization approach on multicore architecture

In the present era, energy is progressively turning into the major limitation in designing multicore chips. However, power and performance are the primary segments of energy, which are contrarily correlated in multicore architectures. This research primarily focused on optimizing energy level of multicore chips using parallel workloads by utilizing either power or execution advancement based on machine learning computation on dynamic programming. To do as such, the novel dynamic machine learning-based heuristic energy optimization (DML-HEO) algorithm has been designed and developed in this research on application-specific controllers to optimize energy-level on multicore architecture. Here DML-HEO is implemented on the controller to maximize the execution inside a fixed power spending plan or to limit the expended capacity to accomplish a similar pattern execution. The controller is additionally scalable as it does not bring about critical overhead due to the increase in quantity of cores. The strategy has been assessed utilizing controllers on a full-framework test system at lab-scale analysis. The experimental results demonstrate that our proposed DML-HEO system shows improving performance than the traditional system.     

Carriers-mediated ferromagnetic enhancement in Al-doped ZnMnO dilute magnetic semiconductors

Nano-crystalline Zn_{0.95 – x}Mn_0.05Al_xO (x = 0, 0.05, 0.10) dilute magnetic semiconductors (DMS) were synthesized by sol–gel derived auto-combustion. X-ray diffraction (XRD) analysis shows that the samples have pure wurtzite structure typical of ZnO without the formation of secondary phases or impurity. Crystallite sizes were approximated by Scherrer formula while surface morphology and grain sizes were measured by field emission scanning electron microscopy. Incorporation of Mn and Al into the ZnO structure was confirmed by energy-dispersive X-ray analysis. Temperature dependent electrical resistivity measurements showed a decreasing trend with the doping of Al in ZnMnO, which is attributable to the enhancement of free carriers. Vibrating sample magnetometer studies confirmed the presence of ferromagnetic behavior at room temperature. The results indicate that Al doping results in significant variation in the concentration of free carriers and correspondingly the carrier-mediated magnetization and room temperature ferromagnetic behavior, showing promise for practical applications. We attribute the enhanced saturation magnetization and electrical conductivity to the exchange interaction mediated by free electrons.     

Weighted average Q-factor calculation for single port filter-antenna measurement

Filter-antenna has many advantages like no need of match network, low insertion loss, ease of design, low cost and light weight. However, practical implementation of filter-antenna requires a precise value of \(Q\) -factor. Filter-antenna is a single device, handling radiating and filtering properties simultaneously, making it difficult to extract \(Q\) -factor for such device. Moreover, filter-antenna has single port and designer is required to calculate \(Q\) -factor from single port. As reported in literature that the available methods for calculation of \(Q\) -factor from single port seem inaccurate. This paper presents a novel \(Q\) -factor calculation method that outperforms existing methods for almost every case of filter-antenna. Experimental results verify the superior performance of proposed method relative existing methods.     

Three-dimensional black-blood multi-contrast carotid imaging using compressed sensing: a repeatability study

Objective

The purpose of this work is to evaluate the repeatability of a compressed sensing (CS) accelerated multi-contrast carotid protocol at 3 T.

Materials and methods

Twelve volunteers and eight patients with carotid disease were scanned on a 3 T MRI scanner using a CS accelerated 3-D black-blood multi-contrast protocol which comprises T ₁w, T ₂w and PDw without CS, and with a CS factor of 1.5 and 2.0. The volunteers were scanned twice, the lumen/wall area and wall thickness were measured for each scan. Eight patients were scanned once, the inter/intra-observer reproducibility of the measurements was calculated.

Results

In the repeated volunteer scans, the interclass correlation coefficient (ICC) for the wall area measurement using a CS factor of 1.5 in PDw, T ₁w and T ₂w were 0.95, 0.81, and 0.97, respectively. The ICC for lumen area measurement using a CS factor of 1.5 in PDw, T ₁w and T ₂w were 0.96, 0.92, and 0.96, respectively. In patients, the ICC for inter/intra-observer measurements of lumen/wall area, and wall thickness were all above 0.81 in all sequences.

Conclusion

The results show a CS accelerated 3-D black-blood multi-contrast protocol is a robust and reproducible method for carotid imaging. Future protocol design could use CS to reduce the scanning time.

     

Beryllium as reflector of MNSR

The article deals with beryllium reflector effects on criticality of a miniature neutron source reactor, and the study of these effects for various cross-section evaluations. D-shape plates of beryllium are added on top of the reactor core to enhance reactivity of the system during operation. Fuel cycle analysis was carried out using SARC code. It was observed that reactivity effects of a particular thickness of beryllium remain nearly same during the whole life of the core. Up to 11% differences were observed between measured and calculated results for various libraries. The nearest match with the measured results was found for JENDL-3.2 library having maximum deviation of 5%.