34,415 research outputs found

    Studying the Dynamical Properties of 20 Nearby Galaxy Clusters

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    Using SDSS-DR7, we construct a sample of 42382 galaxies with redshifts in the region of 20 galaxy clusters. Using two successive iterative methods, the adaptive kernel method and the spherical infall model, we obtained 3396 galaxies as members belonging to the studied sample. The 2D projected map for the distribution of the clusters members is introduced using the 2D adaptive kernel method to get the clusters centers. The cumulative surface number density profile for each cluster is fitted well with the generalized King model. The core radii of the clusters' sample are found to vary from 0.18 Mpc \mbox{h}^{-1} (A1459) to 0.47 Mpc \mbox{h}^{-1} (A2670) with mean value of 0.295 Mpc \mbox{h}^{-1}. The infall velocity profile is determined using two different models, Yahil approximation and Praton model. Yahil approximation is matched with the distribution of galaxies only in the outskirts (infall regions) of many clusters of the sample, while it is not matched with the distribution within the inner core of the clusters. Both Yahil approximation and Praton model are matched together in the infall region for about 9 clusters in the sample but they are completely unmatched for the clusters characterized by high central density. For these cluster, Yahil approximation is not matched with the distribution of galaxies, while Praton model can describe well the infall pattern of such clusters.Comment: 16 pages, 8 figure

    Tugas Dan Fungsi Dakwah Dalam Pemikiran Sayyid Quthub

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    ; Islam adalah agama yang sempurna dan diturunkan oleh Allah untuk mengatur kehidupan. Akan tetapi, kesempurnaan ajaran Islam hanya merupakan ide dan angan-angan saja jika ajaran yang sempurna itu tidak disampaikan kepada manusia. Lebih-lebih jika ajaran itu tidak diamalkan dalam kehidupan manusia. Oleh karena itu, dakwah merupakan suatu aktifitas yang sangat penting dalam ajaran Islam. Menurut Sayyid Quthub, tabligh berarti menyampaikan dan menyeru manusia kepada kebenaran agama, terutama kebenaran aqidah tauhid, karena itu bagi para nabi dan rasul Allah tentang kewajiban tabligh menurut Sayyid Quthub, dikaitkan dengan dua kepentingan ,pertama,tabligh dilakukan untuk member informasi kepada manusia tentang adanya kebenaran dari Allah Swt, lalu mereka diharapkan menerima dan beriman kepada kebenaran yang dibawa para Nabi dan Rasul Allah agar mereka terbebas dari azab Allah. Selanjutnya,kedua tabligh dilakukan sebagai argument (Hajjah) Allah atas manusia, maksudnya dengan tabligh berarti kebenaran telah disampaikan oleh Allah Swt kepada manusia melalui Nabi dan Rasulnya,sehingga tidak ada alas an bagi mereka untuk tidak mengetahui kebenaran itu, Atas dasar itu, Allah Swt berhak untuk member ganjaran kepada orang yang menerima atau menolak kebenaran tersebut, dan inilah makna tabligh sebagai argument tuhan (Hajjah) atas umat manusia. Dakwah sebagai ikhtiar mewujudkan system Islam dalam semua segi kehidupan manusia, dan untuk menjaga dan memelihara kehidupan masyarakat dari keburukan dan kejahatan, maka kegiatan tabligh harus dibarengi dengan amar ma\u27ruf dan nahi mungkar. Kata Kunci: Tugas dan Fungsi, Dakwah, Sayyid Quthub Islam is the perfect religion and lowered by God to organize life. However, the perfection of Islam is only an idea and a delusion if it is not perfect teachings delivered to humans. The more so if teaching is not practiced in the human life. Therefore, the call is an activity that is very important in Islam. According to Sayyid Quthub, means delivering sermons and call people to religious truth, especially the truth Aqeedah of Tawheed, because it is for the prophets and messengers of God\u27s sermons by Sayyid Quthub obligations, associated with the two interests, first, sermons done for member information to people about their the truth of Allah, then they are expected to accept and believe in the truth that brought the Prophet and Messenger of Allah so that they are free from the punishment of God. Furthermore, the two sermons done as an argument (Hajjah) God over man, his point by means of truth has sermons delivered by Allah to mankind through Prophet and His Messenger, so there is no reason for them not to know the truth, On that basis, Allah members are entitled to a reward to the person who accepts or rejects the truth, and this is the meaning of sermons as an argument god (Hajjah) upon mankind. Da\u27wa as a means to realize the system of Islam in all aspects of human life, and to maintain and preserve the lives of the people of Malice and wickedness, the Tabligh activities should be coupled with commanding the good and forbidding the munkar. Keywords: Duties and functions, Da\u27wa, Sayyid Quthu

    Isolates of Some Rotting Fruits Collected at Yankaba Market, Kano, Nigeria

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    Studies on fungi isolates were carried out over a period of 4 weeks with different rotting fruits that were collected from sellers in Yankaba market, Kano. The fruits are sweet orange, apple, pineapple, watermelon, banana, pawpaw, coconut and wild bush mango were collected in clean sterile polythene bags separately. Each of the samples was cultured and isolated at room temperature (370C). Materials used in culturing included Petri-dishes with potato dextrose agar as the media. Methylene blue was used in mounting and slide staining. It took a period of 7 days to incubate and isolate the fungi namely Aspergillus spp., Sclerotium spp., Trichoderma spp., Gloeosporium spp., Rhizopus spp. and Rhizoctonia spp. were responsible for post-harvest deterioration of fresh fruits and vegetables. Rhizopus spp. had the highest frequency of occurrence

    Radiative and Semileptonic B Decays Involving Higher K-Resonances in the Final States

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    We study the radiative and semileptonic B decays involving a spin-JJ resonant KJ(∗)K_J^{(*)} with parity (−1)J(-1)^J for KJ∗K_J^* and (−1)J+1(-1)^{J+1} for KJK_J in the final state. Using the large energy effective theory (LEET) techniques, we formulate B→KJ(∗)B \to K_J^{(*)} transition form factors in the large recoil region in terms of two independent LEET functions ζ⊥KJ(∗)\zeta_\perp^{K_J^{(*)}} and ζ∥KJ(∗)\zeta_\parallel^{K_J^{(*)}}, the values of which at zero momentum transfer are estimated in the BSW model. According to the QCD counting rules, ζ⊥,∥KJ(∗)\zeta_{\perp,\parallel}^{K_J^{(*)}} exhibit a dipole dependence in q2q^2. We predict the decay rates for B→KJ(∗)γB \to K_J^{(*)} \gamma, B→KJ(∗)ℓ+ℓ−B \to K_J^{(*)} \ell^+ \ell^- and B→KJ(∗)ννˉB \to K_J^{(*)}\nu \bar{\nu}. The branching fractions for these decays with higher KK-resonances in the final state are suppressed due to the smaller phase spaces and the smaller values of ζ⊥,∥KJ(∗)\zeta^{K_J^{(*)}}_{\perp,\parallel}. Furthermore, if the spin of KJ(∗)K_J^{(*)} becomes larger, the branching fractions will be further suppressed due to the smaller Clebsch-Gordan coefficients defined by the polarization tensors of the KJ(∗)K_J^{(*)}. We also calculate the forward backward asymmetry of the B→KJ(∗)ℓ+ℓ−B \to K_J^{(*)} \ell^+ \ell^- decay, for which the zero is highly insensitive to the KK-resonances in the LEET parametrization.Comment: 27 pages, 4 figures, 7 tables;contents and figures corrected, title and references revise

    Matrix Gravity and Massive Colored Gravitons

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    We formulate a theory of gravity with a matrix-valued complex vierbein based on the SL(2N,C)xSL(2N,C) gauge symmetry. The theory is metric independent, and before symmetry breaking all fields are massless. The symmetry is broken spontaneously and all gravitons corresponding to the broken generators acquire masses. If the symmetry is broken to SL(2,C) then the spectrum would correspond to one massless graviton coupled to 2N2−12N^2 -1 massive gravitons. A novel feature is the way the fields corresponding to non-compact generators acquire kinetic energies with correct signs. Equally surprising is the way Yang-Mills gauge fields acquire their correct kinetic energies through the coupling to the non-dynamical antisymmetric components of the vierbeins.Comment: One reference adde

    Hubble's law and faster than light expansion speeds

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    Naively applying Hubble's law to a sufficiently distant object gives a receding velocity larger than the speed of light. By discussing a very similar situation in special relativity, we argue that Hubble's law is meaningful only for nearby objects with non-relativistic receding speeds. To support this claim, we note that in a curved spacetime manifold it is not possible to directly compare tangent vectors at different points, and thus there is no natural definition of relative velocity between two spatially separated objects in cosmology. We clarify the geometrical meaning of the Hubble's receding speed v by showing that in a Friedmann-Robertson-Walker spacetime if the four-velocity vector of a comoving object is parallel-transported along the straight line in flat comoving coordinates to the position of a second comoving object, then v/c actually becomes the rapidity of the local Lorentz transformation, which maps the fixed four-velocity vector to the transported one.Comment: 5 pages, 2 figures, to appear in Am. J. Phy

    Squeezed States and Hermite polynomials in a Complex Variable

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    Following the lines of the recent paper of J.-P. Gazeau and F. H. Szafraniec [J. Phys. A: Math. Theor. 44, 495201 (2011)], we construct here three types of coherent states, related to the Hermite polynomials in a complex variable which are orthogonal with respect to a non-rotationally invariant measure. We investigate relations between these coherent states and obtain the relationship between them and the squeezed states of quantum optics. We also obtain a second realization of the canonical coherent states in the Bargmann space of analytic functions, in terms of a squeezed basis. All this is done in the flavor of the classical approach of V. Bargmann [Commun. Pur. Appl. Math. 14, 187 (1961)].Comment: 15 page

    Investigating the Effect of Stratospheric Radiation on Seed Germination and Growth

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    Three seed types: bean (Phaseolus vulgaris), corn (Zea mays) and radish (Raphanus sativus) were flown in a high altitude weather balloon into the mid-stratosphere to investigate the effects of high altitude radiation on germination success and seedling growth. After recovering and planting the seeds, the bean seeds showed lower germination success with exposure to high altitude radiation, and consequently stunted seedling growth. Cord and radish seeds experienced a statistically significant positive effect on germination success form radiation exposure compared to control seeds, but negative effect on seedling growth. Overall, the field experiments presented here support laboratory studies that show radiation exposure on vegetable seeds has a mixed effect on the germination success and negative effect on seedling growth on investigated seed types
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