235 research outputs found

    Approximate Noether Symmetries of the Geodesic Equations for the Charged-Kerr Spacetime and Rescaling of Energy

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    Using approximate symmetry methods for differential equations we have investigated the exact and approximate symmetries of a Lagrangian for the geodesic equations in the Kerr spacetime. Taking Minkowski spacetime as the exact case, it is shown that the symmetry algebra of the Lagrangian is 17 dimensional. This algebra is related to the 15 dimensional Lie algebra of conformal isometries of Minkowski spacetime. First introducing spin angular momentum per unit mass as a small parameter we consider first-order approximate symmetries of the Kerr metric as a first perturbation of the Schwarzschild metric. We then consider the second-order approximate symmetries of the Kerr metric as a second perturbation of the Minkowski metric. The approximate symmetries are recovered for these spacetimes and there are no non-trivial approximate symmetries. A rescaling of the arc length parameter for consistency of the trivial second-order approximate symmetries of the geodesic equations indicates that the energy in the charged-Kerr metric has to be rescaled and the rescaling factor is rr-dependent. This rescaling factor is compared with that for the Reissner-Nordstr\"{o}m metric.Comment: 17 Page

    Analysis of Reconstructed Modified f(Q,T) Gravity

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    This paper studies the reconstruction criterion in the framework of f(Q,T)f(Q,T) gravity using ghost dark energy model, where QQ represents the non-metricity and TT is the trace of energy-momentum tensor. In this regard, the correspondence scenario for a non-interacting scheme is used to construct the ghost dark energy f(Q,T)f(Q,T) model. We consider the flat Friedmann-Robertson-Walker universe with power-law scale factor and pressure-less matter. We investigate the behavior of equation of state parameter and examine the stability of ghost dark energy model via squared speed of sound parameter. The equation of state parameter depicts the phantom era, while the squared speed of sound reveals stable ghost dark energy model for the entire cosmic evolutionary paradigm. Finally, we study the cosmography of the ωGDEωGDE\omega_{GDE}-\omega'_{GDE} and rsr-s planes that correspond to freezing region and Chaplygin gas model, respectively. It is concluded that the reconstructed ghost dark energy model represents the evolution of the cosmos for suitable choices of the parametric values.Comment: 34 pages, 6 figure

    Diving deep into digital literacy:emerging methods for research

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    Literacy studies approaches have tended to adopt a position which enables ethnographic explorations of a wide range of ‘literacies’. An important issue arising is the new challenge required for researchers to capture, manage, and analyse data that highlight the unique character of practices around texts in digital environments. Such inquiries, we argue, require multiple elements of data to be captured and analysed as part of effective literacy ethnographies. These include such things as the unfolding of digital texts, the activities around them, and features of the surrounding social and material environment. This paper addresses these methodological issues drawing from three educationally focused studies, and reporting their experiences and insights within uniquely different contexts. We deal with the issue of adopting new digital methods for literacy research through the notion of a ‘deep dive’ to explore educational tasks in classrooms. Through a discussion of how we approached the capture and analysis of our data, we present methods to better understand digital literacies in education. We then outline challenges posed by our methods, how they can be used more broadly for researching interaction in digital environments, and how they augment transdisciplinary debates and trends in research methods

    A cross-sectional study to determine sex-wise prevalence of obesity in adults of Kashmiri population

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    Background: Aim of current study was to determine the prevalence of obesity in both sexes in persons aged 18-45 years.Methods: Multistage and multiphasic sampling technique was utilized in this study to screen the obese subjects of  both males and females based on WHO classification of obesity according to BMI of 18-45 years of age. Each household was visited and only the subjects having age of 18-45 years were included in this study and this comprised of 5107 subjects, then identified obese cases with the help of height and weight techniques. Only those people who had simple obesity were included in the study. People having secondary obesity, drug induced obesity and pregnant ladies were excluded from this study. The data was collected and analysed using statistical software and chi square and proportional statistical test were applied.Results: Out of 5107 screened population, 2652 were males and 2455 were females and the prevalence of male obesity in study population is 6.41% and that of females is 7.74%.Conclusion: The sex has a significant impact on obesity. We reported in our study a prevalence of obesity is more in females as compared to males. A lack of physical activity as well as low frequency of employment makes females more susceptible to obesity.

    Traversable wormholes in the extended teleparallel theory of gravity with matter coupling

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    This study explores the Gaussian and the Lorentzian distributed spherically symmetric wormhole solutions in the f(τ,T)f(\tau, T) gravity. The basic idea of the Gaussian and Lorentzian noncommutative geometries emerges as the physically acceptable and substantial notion in quantum physics. This idea of the noncommutative geometries with both the Gaussian and Lorentzian distributions becomes more striking when wormhole geometries in the modified theories of gravity are discussed. Here we consider a linear model within f(τ,T)f(\tau,T) gravity to investigate traversable wormholes. In particular, we discuss the possible cases for the wormhole geometries using the Gaussian and the Lorentzian noncommutative distributions to obtain the exact shape function for them. By incorporating the particular values of the unknown parameters involved, we discuss different properties of the new wormhole geometries explored here. It is noted that the involved matter violates the weak energy condition for both the cases of the noncommutative geometries, whereas there is a possibility for a physically viable wormhole solution. By analyzing the equilibrium condition, it is found that the acquired solutions are stable. Furthermore, we provide the embedded diagrams for wormhole structures under Gaussian and Lorentzian noncommutative frameworks. Moreover, we present the critical analysis on an anisotropic pressure under the Gaussian and the Lorentzian distributions.Comment: 20 pages, 13 figures, submitted for publicatio

    State-tribal relations in the British India: a study of the Yousafzai’s armed resistance in the Northwest Frontier region

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    This paper aims to shed limelight on the Pakhtun tribal resistance in the North-West Frontier region (now Khyber Pakhtunkhwa) against the colonial masters of British India. The purpose of this research is to highlight the induction of the British troops into the North-West Frontier tribal areas in the form of different war campaigns and the local Pashtun tribes\u27 responses in the form of armed resistance. This subject is essential for the researchers to know the reality of the Pashtun tribes and, more importantly, different wars fought between British India\u27s army and the Pashtun tribes on different battlefields. The methodology adopted for this research is a descriptive study, and the data collection is based on secondary data, which is analysed through content analysis techniques. The period from 1862 to 1888 is taken under consideration, and the causes that triggered the clashes, such as the Siege of Malakand (North Camp), the Ambeyla Campaign (near Buner) and the Black Mountain Expedition (Hazara areas). The findings of the study are that the Yousafzai tribe presented massive resistance and proved their effectiveness in the wars

    Phytotoxic, Antibacterial and Haemagglutination activities of the aerial parts of Myrsine africana L.

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    The crude methanolic extract and various fractions derived from the aerial parts of Myrsine africana were screened in vitro for possible phytotoxic, antibacterial and haemagglutination activities. Moderate phytotoxic activity (31.25 %) was observed against Lemna minor L at 1000 μg/ml by chloroform fraction (CHCl3). The crude methanolic extract and CHCl3 fraction showed good antibacterial activity against Klebsiella pneumoniae (MIC50 = 2.45 and 2.1 mg/ml respectively). The crude methanolic extract and other fractions showed moderate activity against tested bacterial strains. The CHCl3 and aqueous fractions showed no activity against Escherichia coli. Similarly, the ethyl acetate (EtOAc) and butanol (BuOH) fractions were found to be non active against Bacillus pumilus and Enterobacter aerogenes, respectively. Moderate haemagglutination activity was observed against human red blood cells (RBCs) of blood group AB- by crude methanolic extract and CHCl3 fraction and against AB+ by aqueous fraction, respectively. The plant specie can be a source of antibacterial agent(s) and phytolectins.Keywords: Myrsine africana, phytotoxicity, haemagglutination, antibacterial and MIC5

    Compact quad-element high-isolation wideband mimo antenna for mm-wave applications

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    This paper presents a multiple-input multiple-output (MIMO) antenna system for millimeter-wave 5G wireless communication services. The proposed MIMO configuration is composed of four antenna elements, where each antenna possesses an HP-shaped configuration that features simple configuration and excellent performance. The proposed MIMO design can operate at a very wideband of 36.83-40.0 GHz (measured). Furthermore, the proposed MIMO antenna attains a peak gain of 6.5 dB with a maximum element-isolation of -45 dB. Apart from this, the MIMO performance metrics such as envelope correlation coefficient (ECC), diversity gain, and channel capacity (CCL) are analyzed, which demonstrate good characteristics across the operating band. The proposed antenna radiates efficiently with a radiation efficiency of above 80% at the desired frequency band which makes it a potential contender for the upcoming communication applications. The proposed design simulations were performed in the computer simulation technology (CST) software, and measured results reveal good agreement with the simulated one

    Design of a Dual Band SNG Metamaterial Based Antenna for LTE 46/WLAN and Ka-Band Applications

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    The non-existing properties of the metamaterial surfaces can be utilized to improve the antenna radiation characteristics. In this article, a design and performance analysis of a Single Negative (SNG) metamaterial based antenna is imparted for LTE 46/WLAN and Ka-band (like in satellite communication for the receiving side) applications. The unit cell of the metamaterial surface exhibits negative permittivity and positive permeability; yielding a high magnitude positive refractive index, is used to improve and analyze the performance of the proposed monopole antenna element. The proposed SNG based antenna covers a -10 dB bandwidth from 5.35-5.69 GHz (LTE 46/WLAN) and 17.81-20.67 GHz (Ka-band). The total size of the proposed antenna element is 20.2 x 28 .4 mm(2) while a 2 x 3 SNG metamaterial surface is used at the back of the antenna element which improves the gain from 4.52 dB to 9.13 dB for the desired Ka band and 1.17 to 5.04 dB for the LTE 46/WLAN band. Furthermore, for the LTE 46/WLAN frequency band, the impedance matching also gets better, resulting in the return loss improvement from -11 dB to -32.4 dB. Moreover, the radiation efficiency is also improved by more than 10 % for the Ka band after employing the SNG metamaterial surface. The measured results fall in good agreement with the simulated one and make the proposed SNG metamaterial based antenna design competent for the LTE 46/WLAN and Ka-band (like in satellite communication for the receiving side) applications

    Iron slag/activated carbon-electrokinetic system with anolyte recycling for single and mixture heavy metals remediation.

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    The electrokinetic process has been proposed for in-situ soil remediation to minimize excavation work and exposure to hazardous materials. The precipitation of heavy metals in alkaline pH near the cathode is still challenging. Reactive filter media and enhancement agents have been used in electrokinetics to enhance the removal of heavy metals. This study investigated coupling industrial iron slag waste and iron slag-activated carbon reactive filter media with electrokinetic for a single and mixture of heavy metals treatment. Instead of using acid enhancement agents, the anolyte solution was recycled to neutralize the alkaline front at the cathode, reducing the operation cost and chemical use. Experiments were conducted for 2 and 3 weeks at 20 mA electric current. Copper removal increased from 3.11 % to 23 % when iron slag reactive filter media was coupled with electrokinetic. Copper removal increased to 70.14 % in the electrokinetic experiment with iron slag-activated carbon reactive filter media. The copper removal increased to 89.21 % when the anolyte solution was recycled to the cathode compartment. Copper removal reached 93.45 % when the reactive filter media-electrokinetic process with anolyte recirculation was extended to 3 weeks. The reactive filter media- an electrokinetic process with anolyte recycling was evaluated for removing copper, nickel, and zinc mixture, and results revealed 81.1 % copper removal, 89.04 % nickel removal, and 92.31 % zinc removal in a 3-week experiment. The greater nickel and zinc removal is attributed to their higher solubility than copper. The results demonstrated the cost-effectiveness and efficiency of the electrokinetic with iron slag-activated carbon reactive filter media with anolyte recirculation for soil remediation from heavy metals
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