2,310 research outputs found

    Generalized second law of thermodynamics for FRW cosmology with logarithmic correction

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    In the previous analyses in the literature about the generalized second law (GSL) in an accelerated expanding universe the usual area relation for the entropy, i.e. S=A4GS={A\over 4G}, was used for the cosmological horizon entropy. But this entropy relation may be modified due to thermal and quantum fluctuations or corrections motivated by loop quantum gravity giving rise to S={A\over 4}+\pi\alpha \ln({A\over 4})+\gamma, where α\alpha and γ\gamma are some constants whose the values are still in debate in the literature. Our aim is to study the constraints that GSL puts on these parameters. Besides, we investigate the conditions that the presence of such modified terms in the entropy puts on other physical parameters the system such as the temperature of dark energy via requiring the validity of GSL. In our study we consider a spatially flat Friedman-Robertson-Walker and assume that the universe is composed of several interacting components (including dark energy). The model is investigated in the context of thermal equilibrium and non-equilibrium situations. We show that in a (super) accelerated universe GSL is valid whenever α(0\alpha (0 leading to a (negative) positive contribution from logarithmic correction to the entropy. In the case of super acceleration the temperature of the dark energy is obtained to be less or equal to the Hawking temperature.Comment: 14 pages, accepted for publication in Europhysics Letter

    Matrix Representation of Octonions and Generalizations

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    We define a special matrix multiplication among a special subset of 2N\x 2N matrices, and study the resulting (non-associative) algebras and their subalgebras. We derive the conditions under which these algebras become alternative non-associative and when they become associative. In particular, these algebras yield special matrix representations of octonions and complex numbers; they naturally lead to the Cayley-Dickson doubling process. Our matrix representation of octonions also yields elegant insights into Dirac's equation for a free particle. A few other results and remarks arise as byproducts.Comment: 18 printed page

    Attractor Solutions in f(T) Cosmology

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    In this paper, we explore the cosmological implications of interacting dark energy model in a torsion based gravity namely f(T)f(T). Assuming dark energy interacts with dark matter and radiation components, we examine the stability of this model by choosing different forms of interaction terms. We consider three different forms of dark energy: cosmological constant, quintessence and phantom energy. We then obtain several attractor solutions for each dark energy model interacting with other components. This model successfully explains the coincidence problem via the interacting dark energy scenario.Comment: 10 pages, 23 figures, version accepted for publication in European Physical Journal C (2012

    pengembangan Metode Bermain Puzzle Untuk Meningkatkan Kemampuan Membaca Kata Pada Kelompok B Di Raodatul Athfal (RA) Farida Aryani Makassar.

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    ABSTRAK Rumusan masalah dalam pengembangan pembelajaran ini adalah bagaimana mengembangkan kegiatan bermain puzzle untuk meningkatkan kemampuan membaca kata anak Kelompok B di RA Farida Aryani Makassar. Tujuan pengembangan pembelajaran untuk memperoleh gambaran dalam pengembangan metode bermain puzzle untuk meningkatkan kemampuan membaca kata pada kelompok B di RA Farida Aryani. Pendekatan yang digunakan dalam pengembangan ini adalah pendekatan kualitatif dan jenis penyelesaian adalah Skripsi Pengembangan Pembelajaran. Fokus pengembangan ini adalah pengembangan metode bermain puzzle untuk meningkatkan kemampuan membaca kata. Prosedur pengembangan meliputi perencanaan, pelaksanaan, observasi, dan refleksi. Subjek dalam pengembangan ini adalah kelompok B Raodatul Athfal (RA) Farida Aryani Makassar yaitu 1 orang guru dan anak didik yang berjumlah 10 orang, yang terdiri atas 5 anak laki – laki dan 5 anak perempuan. Teknik pengumpulan data yang digunakan yaitu observasi dan dokumentasi. Hasil pengembangan pembelajaran menunjukkan bahwa dengan menggunakan metode bermain puzzle maka dapat meningkatkan kemampuan membaca pada kelompok B di Raodatul Athfal (RA) Farida Aryani Makassar. Hal ini dapat dilihat pada pertemuan I terdapat 4 anak didik atau 40% yang mampu menyebutkan huruf abjad tanpa bantuan guru. Pertemuan II terdapat 4 anak didik atau 40% yang mampu menyebutkan huruf abjad. Pertemuan III terdapat 6 anak atau 60% yang mampu menyebutkan huruf awal dari nama benda / gambar yang ada. Pertemuan IV terdapat 7 anak atau 70% yang mampu menyebutkan suku kata awal dan akhir. Pertemuaan V terdapat 8 anak atau 80% yang mampu menghubungkan kata sesuai dengan gambar yang ada

    Affine invariant signed-rank multivariate exponentially weighted moving average control chart for process location monitoring

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    Multivariate statistical process control (SPC) charts for detecting possible shifts in mean vectors assume that data observation vectors follow a multivariate normal distribution. This assumption is ideal and seldom met. Nonparametric SPC charts have increasingly become viable alternatives to parametric counterparts in detecting process shifts when the underlying process output distribution is unknown, specifically when the process measurement is multivariate. This study examined a new nonparametric signed-rank multivariate exponentially weighted moving average type (SRMEWMA) control chart for monitoring location parameters. The control chart was based on adapting a multivariate spatial signed-rank test. The test was affine-invariant and the weighted version of this test was used to formulate the charting statistic by incorporating the exponentially weighted moving average (EWMA) scheme. The test\u27s in-control (IC) run length distribution was examined and the IC control limits were established for different multivariate distributions, both elliptically symmetrical and skewed. The average run length (ARL) performance of the scheme was computed using Monte Carlo simulation for select combinations of smoothing parameter, shift, and number of p-variate quality characteristics. The ARL performance was compared to the performance of the multivariate exponentially weighted moving average (MEWMA) and Hotelling T2. The control charts for observation vectors sampled the multivariate normal, multivariate t, and multivariate gamma distributions. The SRMEWMA control chart was applied to a real dataset example from aluminum smelter manufacturing that showed the SRMEWMA performed well. The newly investigated nonparametric multivariate SPC control chart for monitoring location parameters--the Signed-Rank Multivariate Exponentially Weighted Moving Average (SRMEWMA)--is a viable alternative control chart to the parametric MEWMA control chart and is sensitive to small shifts in the process location parameter. The signed-rank multivariate exponentially weighted moving average performance for data from elliptically symmetrical distributions is similar to that of the MEWMA parametric chart; however, SRMEWMA\u27s performance is superior to the performance of the MEWMA and Hotelling\u27s T2 control charts for data from skewed distributions

    Effect of Piper betle and Brucea javanica on the Differential Expression of Hyphal Wall Protein (HWP1) in Non-Candida albicans Candida (NCAC) Species

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    The study aimed to identify the HWP1 gene in non-Candida albicans Candida species and the differential expression of HWP1 following treatment with Piper betle and Brucea javanica aqueous extracts. All candidal suspensions were standardized to 1 x 10(6) cells/mL. The suspension was incubated overnight at 37 degrees C (C. parapsilosis, 35 degrees C). Candidal cells were treated with each respective extract at 1, 3, and 6 mg/mL for 24 h. The total RNA was extracted and reverse transcription-polymerase chain reaction was carried out with a specific primer of HWP1. HWP1 mRNAs were only detected in C. albicans, C. parapsilosis, and C. tropicalis. Exposing the cells to the aqueous extracts has affected the expression of HWP1 transcripts. C. albicans, C. parapsilosis, and C. tropicalis have demonstrated different intensity of mRNA. Compared to P. betle, B. javanica demonstrated a higher suppression on the transcript levels of HWP1 in all samples. HWP1 was not detected in C. albicans following the treatment of B. javanica at 1 mg/mL. In contrast, C. parapsilosis and C. tropicalis were shown to have HWP1 regulation. However, the expression levels were reduced upon the addition of higher concentration of B. javanica extract. P. betle and B. javanica have potential to be developed as oral health product.Article Link : http://www.hindawi.com/journals/ecam/2013/397268

    On Contra SS-Continuous Functions

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    In this paper, we apply the notion of -open set in topological spaces to introduce and investigate the concept of contra -continuous which is a subclass of the class of contra semi continuous functions. Keywords: -closed, contra -continuous, contra SS –closed and strongly contra SS –closed

    Contribution of genes polymorphism to susceptibility and outcome of sepsis

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    Sepsis and its sequelae are still a major cause of morbidity and mortality in intensive care units (ICU). The evidence that endogenous mediators actually mediate the individual’s response to infection has led to various approaches to assess the individual’s contribution to the course of thedisease. The role of an individual’s genetic background and predisposition for the extent of inflammatory responses is determined by variability of genes encoding endogenous mediators that constitute the pathways of inflammation. Pro- and anti-inflammatory responses contribute to thesusceptibility and outcome of patients with systemic inflammation and sepsis. Therefore, all genes encoding proteins involved in the transduction of inflammatory processes are candidate genes to determine the human genetic background that is responsible for interindividual differences in systemic inflammatory responses. Polymorphism of TNA a, TNFB, IL-10, IL-6, IL-1b, IL-1RN, HMGB1, TLR, PAI-1, DEFB1, HSP and MMP-9 has contribution to susceptibility and outcome of sepsis in some research. Examination of the association between genetic polymorphisms and sepsispromises to provide clinicians with new tools to evaluate prognosis, to intervene early and aggressively in treating high risk persons, and to avoid the use of therapies with adverse effects in treating low risk persons. Genomic information may be useful to use to identify groups ofpatients with a high risk of developing severe sepsis and multiple organ dysfunctions

    Estimation of Vehicle Damage Cost Involved in Road Traffic Accidents in Karachi, Pakistan: A Geospatial Perspective

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    AbstractRoad Traffic Accidents (RTAs) are serious but ignored problem in Pakistan. Now this problem is under limelight due to disastrous impacts over society in general and over economy in particular. Karachi is considered to be the most income generating city of Pakistan. This city holds a typical feature of most road traffic accidents facing in the country and the fourth highest RTA fatalities in the world. More than 26,000 road accidents occur on the arteries of Karachi every year making it a worrisome place. Outcome of RTAs could be measured in tangible manner i.e., in term of number of life loss but intangible losses are very difficult to measure. In this paper an attempt has been made to capture the potential flaws in road geometry through Remote Sensing and embedding the land use data through the inventory of Geographic Information Systems. Moreover, overlay analysis techniques helps in identifying the high accident cost areas. In Karachi, over 35,000 vehicles are involved in crashes every year, resulting in loss of life as well as wealth. The overall repair cost over the vehicles involved in all types of RTAs in year2012 is more than 20,000,000 PKR with Landhi Town showing the highest cost. Shah Faisal Town showed the minimum repair cost of over 300,000 due to its small aerial extent and lesser number of economic land use making it a safer place for vehicle users. Moreover, map of Karachi showing the spatial pattern of vehicle repair cost. It is suggested that the serious measures need to be undertaken to combat this problem
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