107 research outputs found
BER analysis of BPSK-SIM-based SISO and MIMO FSO systems in strong turbulence with pointing errors
Free space optics (FSO) is one of the sprouting technologies in optical communication systems domain.It can be employed as an alternative for the conventional radio frequency (RF) links to work out thecurrent limitations in communication systems. But, the major drawback in FSO communication is theeffect of random environment conditions on its performance. In this paper, we analyze the bit errorrate (BER) and outage performance of single-input single-output (SISO) and multiple-input multiple-output (MIMO) FSO systems in strong atmospheric turbulence using binary phase shift keying subcarrierintensity modulation (BPSK-SIM) signaling technique. The closed-form expressions are derived and theresults are realized in terms of 2D and 3D plots.http://www.elsevier.de/ijleo2015-11-30hb201
Real-time Internet of Things Architecture for Wireless Livestock Tracking
Automatic livestock tracking is necessary for countries facing stock theft problems, like South Africa and Kenya. This paper presents a conceptual design of architecture for real-time wireless livestock tracking based on Internet of Things paradigm. It is a hierarchical model consisting of three building blocks, where the first block is represented with wireless sensor network. Additionally, we have developed a low-power device for livestock tracking in an outdoor environment. The animal tracking device (AnTrack) is self-sustainable with a watertight solar panel(s), designed as a collar to be worn by the animals. A detailed analysis of the AnTrack power consumption proves that the device is capable to generate enough supply power, even when there is no sunshine for a week. This device can be used as a robust building block of future real-time Internet of Things livestock tracking solutions
ПОЛУЧЕНИЕ ПОЛОС ПЕРЕМЕННОЙ ТОЛЩИНЫ С РЕГУЛИРУЕМЫМ УШИРЕНИЕМ
The paper describes flow chart of strip rolling with variable thickness in the rolls with changeable clearance between them and non-driven rollers that ensure spread widening control. The paper presents necessary formulae for calculation of backward tension in the rolls which is considered as drawing tension in the rollers. Accomplishment of the given process is theoretically substantiated in the paper.Описана технологическая схема прокатки полос переменной толщины в валках с изменяющимся зазором между ними и неприводных роликах, обеспечивающих контролируемое уширение. Представлены необходимые формулы для расчета заднего натяжения в валках, являющегося напряжением протягивания полосы в роликах, теоретически обоснована возможность осуществления данного процесса
ОПРЕДЕЛЕНИЕ ПАРАМЕТРОВ ПРОЦЕССА ПРОДОЛЬНОЙ ПРОКАТКИ ДЛЯ ПОЛУЧЕНИЯ ПОЛОС ПЕРЕМЕННОЙ ТОЛЩИНЫ С НАРАСТАЮЩИМ ОБЖАТИЕМ
The paper considers problems pertaining to determination of calculated values of a critical angle in the case of rolling strips of variable thickness with increasing reduction. Equations for calculation of an average normal contact pressure and rolling moment are obtained in the paper.Рассмотрены вопросы по определению расчетных значений критического угла в случае прокатки полос переменной толщины с нарастающим обжатием, получены уравнения для расчета среднего нормального контактного напряжения и момента прокатки.
The antioxidant and antiproliferative activities of methanolic extracts from Njavara rice bran
<p>Abstract</p> <p>Background</p> <p>Free radical-induced oxidative stress is the root cause for many human diseases. Naturally occurring antioxidant supplements from plants are vital to counter the oxidative damage in cells. The main objective of the present study was to characterize the antioxidant and antiproliferative potential of rice bran extracted from an important Indian rice variety, Njavara and to compare the same with two commercially available basmati rice varieties: Vasumathi, Yamini and a non medicinal variety, Jyothi.</p> <p>Methods</p> <p>Methanolic extracts of rice bran from four varieties; Vasumathi, Yamini, Jyothi and Njavara were used to study their total phenolic and flavonoid contents, <it>in vitro </it>antioxidant activities including total antioxidant activity, scavenging of nitric oxide and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical, reducing power and cytotoxic activity in C6 glioma cells. Correlation coefficient and regression analysis were done by using Sigmastat version 3.1 and Stata statistical package respectively.</p> <p>Results</p> <p>Rice bran methanolic extract from Njavara showed the highest antioxidant and cell cytotoxic properties compared to the other three rice varieties. IC<sub>50 </sub>values for scavenging DPPH and nitric oxide were in the range of 30.85-87.72 μg/ml and 52.25-107.18 μg/ml respectively. Total antioxidant activity and reducing power were increased with increasing amounts of the extract. Total phenolic and flavonoid contents were in the range of 3.2-12.4 mg gallic acid-equivalent (GAE)/g bran and 1.68-8.5 mg quercetin-equivalent (QEE)/g bran respectively. IC<sub>50 </sub>values of cytotoxic assay (MTT assay) were 17.53-57.78 μg/ml. Correlation coefficient and regression analysis of phenolic content with DPPH and NO scavenging, MTT (-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay, total antioxidant assay and reducing power showed a highly significant correlation coefficient values (96-99%) and regression values (91-98%).</p> <p>Conclusion</p> <p>The results of the present study show that the crude methanolic extract from Njavara rice bran contains significantly high polyphenolic compounds with superior antioxidant activity as evidenced by scavenging of free radicals including DPPH and NO. Njavara extracts also showed highest reducing power activity, anti-proliferative property in C6 glioma cells. In conclusion, it is conceivable that the Njavara rice variety could be exploited as one of the potential sources for plant - based pharmaceutical products.</p
A Phylogeny and Timescale for the Evolution of Pseudocheiridae (Marsupialia: Diprotodontia) in Australia and New Guinea
Pseudocheiridae (Marsupialia: Diprotodontia) is a family of endemic Australasian arboreal folivores, more commonly known as ringtail possums. Seventeen extant species are grouped into six genera (Pseudocheirus, Pseudochirulus, Hemibelideus, Petauroides, Pseudochirops, Petropseudes). Pseudochirops and Pseudochirulus are the only genera with representatives on New Guinea and surrounding western islands. Here, we examine phylogenetic relationships among 13 of the 17 extant pseudocheirid species based on protein-coding portions of the ApoB, BRCA1, ENAM, IRBP, Rag1, and vWF genes. Maximum parsimony, maximum likelihood, and Bayesian methods were used to estimate phylogenetic relationships. Two different relaxed molecular clock methods were used to estimate divergence times. Bayesian and maximum parsimony methods were used to reconstruct ancestral character states for geographic provenance and maximum elevation occupied. We find robust support for the monophyly of Pseudocheirinae (Pseudochirulus + Pseudocheirus), Hemibelidinae (Hemibelideus + Petauroides), and Pseudochiropsinae (Pseudochirops + Petropseudes), respectively, and for an association of Pseudocheirinae and Hemibelidinae to the exclusion of Pseudochiropsinae. Within Pseudochiropsinae, Petropseudes grouped more closely with the New Guinean Pseudochirops spp. than with the Australian Pseudochirops archeri, rendering Pseudochirops paraphyletic. New Guinean species belonging to Pseudochirops are monophyletic, as are New Guinean species belonging to Pseudochirulus. Molecular dates and ancestral reconstructions of geographic provenance combine to suggest that the ancestors of extant New Guinean Pseudochirops spp. and Pseudochirulus spp. dispersed from Australia to New Guinea ∼12.1–6.5 Ma (Pseudochirops) and ∼6.0–2.4 Ma (Pseudochirulus). Ancestral state reconstructions support the hypothesis that occupation of high elevations (>3000 m) is a derived feature that evolved on the terminal branch leading to Pseudochirops cupreus, and either evolved in the ancestor of Pseudochirulus forbesi, Pseudochirulus mayeri, and Pseudochirulus caroli, with subsequent loss in P. caroli, or evolved independently in P. mayeri and P. forbesi. Divergence times within the New Guinean Pseudochirops clade are generally coincident with the uplift of the central cordillera and other highlands. Diversification within New Guinean Pseudochirulus occurred in the Plio-Pleistocene after the establishment of the Central Range and other highlands
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