121 research outputs found

    Ekstrak Bawang Putih Bubuk Dengan Menggunakan Proses Spray Drying

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    Bawang putih banyak digunakan sebagai bumbu utama pada berbagai masakan karena aromanya yang khas. Aroma khas tersebut karena adanya komponen aktif (Allicin) pada bawang putih. Allicin juga berguna untuk daya anti kolesterol yang dapat mencegah penyakit jantung, tekanan darah tinggi dan lain sebagainya. Komponen Allicin bersifat volatil sehingga bila penanganannya salah maka dapat menyebabkan kerusakan. Untuk mengawetkan bawang putih yaitu dengan cara pengeringan. Salah satu proses yang dapat digunakan adalah spray drying karena proses ini membutuhkan waktu yang singkat. Proses spray drying adalah proses pengeringan dengan cara menyemprotkan fase cair menjadi butiran-butiran kecil kemudian mengontakkannya dengan udara panas sehingga menjadi bubuk. Umpan yang akan dikeringkan dapat berupa larutan ataupun suspensi dengan viskositas tertentu. Penelitian ini dilakukan percobaan pembuatan ekstrak bawang putih bubuk dengan variasi perbandingan massa bawang putih dengan pelarut air tertentu yang dimulai dari perbandingan 1:1, variasi konsentrasi maltodekstrin 0%, 10%, 20%, 30%, 40% dan 50%, serta variasi suhu udara masuk 160 oC, 170 oC, 180 oC dan 190 oC. Hal yang diamati adalah pengaruh konsentrasi maltodekstrin dan suhu udara masuk terhadap karakteristik ekstrak bawang putih bubuk yang dihasilkan. Karakteristik bubuk yang dianalisa meliputi kadar air, bulk density, wettability, solubility dan organoleptik. Dari hasil analisa diketahui bahwa dengan meningkatnya suhu udara inlet menyebabkan terjadinya penurunan kadar air. Begitu juga dengan meningkatnya suhu udara masuk menyebabkan terjadinya peningkatan bulk density, wettability dan solubility

    Stochastic homogenization of the laser intensity to improve the irradiation uniformity of capsules directly driven by thousands laser beams

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    Illumination uniformity of a spherical capsule directly driven by laser beams has been assessed numerically. Laser facilities characterized by ND = 12, 20, 24, 32, 48 and 60 directions of irradiation with associated a single laser beam or a bundle of NB laser beams have been considered. The laser beam intensity profile is assumed super-Gaussian and the calculations take into account beam imperfections as power imbalance and pointing errors. The optimum laser intensity profile, which minimizes the root-mean-square deviation of the capsule illumination, depends on the values of the beam imperfections. Assuming that the NB beams are statistically independents is found that they provide a stochastic homogenization of the laser intensity associated to the whole bundle, reducing the errors associated to the whole bundle by the factor  , which in turn improves the illumination uniformity of the capsule. Moreover, it is found that the uniformity of the irradiation is almost the same for all facilities and only depends on the total number of laser beams Ntot = ND × NB

    Nucleus-Electron Model for States Changing from a Liquid Metal to a Plasma and the Saha Equation

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    We extend the quantal hypernetted-chain (QHNC) method, which has been proved to yield accurate results for liquid metals, to treat a partially ionized plasma. In a plasma, the electrons change from a quantum to a classical fluid gradually with increasing temperature; the QHNC method applied to the electron gas is in fact able to provide the electron-electron correlation at arbitrary temperature. As an illustrating example of this approach, we investigate how liquid rubidium becomes a plasma by increasing the temperature from 0 to 30 eV at a fixed normal ion-density 1.03×1022/cm31.03 \times 10^{22}/cm^3. The electron-ion radial distribution function (RDF) in liquid Rb has distinct inner-core and outer-core parts. Even at a temperature of 1 eV, this clear distinction remains as a characteristic of a liquid metal. At a temperature of 3 eV, this distinction disappears, and rubidium becomes a plasma with the ionization 1.21. The temperature variations of bound levels in each ion and the average ionization are calculated in Rb plasmas at the same time. Using the density-functional theory, we also derive the Saha equation applicable even to a high-density plasma at low temperatures. The QHNC method provides a procedure to solve this Saha equation with ease by using a recursive formula; the charge population of differently ionized species are obtained in Rb plasmas at several temperatures. In this way, it is shown that, with the atomic number as the only input, the QHNC method produces the average ionization, the electron-ion and ion-ion RDF's, and the charge population which are consistent with the atomic structure of each ion for a partially ionized plasma.Comment: 28 pages(TeX) and 11 figures (PS

    Regulatory T cell epitopes (Tregitopes) in IgG induce tolerance in vivo and lack immunogenicity per se

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    Tregitopes are a set of epitopes, derived from IgG, that bind to MHCII, activate nTregs, and promote tolerance. We have now confirmed that coadministration of Tregitopes with a range of proteins (autoantigens and nominal antigens, such as OVA) in vitro and in vivo leads to suppression of T cell and antibody responses to the test antigens. In this study, we demonstrate that Tregitopes are not immunogenic in vivo even when emulsified with strong adjuvants, such as IFA or CFA. Moreover, in vivo administration of Tregitopes with IFA or CFA does not induce Th1 or Th2 cytokine expression under restimulation conditions in vitro. We investigated tolerance induction by codelivering Tregitopes with OVA using B cells. When B cells were pulsed with OVA plus Tregitopes and transferred into naïve mice, we found that cellular and humoral immune responses to the OVA were suppressed. As a result of their ability to induce Tregs and the absence of immunogenicity in the context of strong adjuvants, Tregitopes might be considered a novel immunomodulatory approach for the suppression of immune responses to protein therapeutics (such as FVIII and mAb), as well as for treatment of autoimmune diseases

    Exploration of the Transition from the Hydrodynamiclike to the Strongly Kinetic Regime in Shock-Driven Implosions

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    Clear evidence of the transition from hydrodynamiclike to strongly kinetic shock-driven implosions is, for the first time, revealed and quantitatively assessed. Implosions with a range of initial equimolar D[superscript 3]He gas densities show that as the density is decreased, hydrodynamic simulations strongly diverge from and increasingly overpredict the observed nuclear yields, from a factor of ∼2 at 3.1  mg/cm[superscript 3] to a factor of 100 at 0.14  mg/cm[superscript 3]. (The corresponding Knudsen number, the ratio of ion mean-free path to minimum shell radius, varied from 0.3 to 9; similarly, the ratio of fusion burn duration to ion diffusion time, another figure of merit of kinetic effects, varied from 0.3 to 14.) This result is shown to be unrelated to the effects of hydrodynamic mix. As a first step to garner insight into this transition, a reduced ion kinetic (RIK) model that includes gradient-diffusion and loss-term approximations to several transport processes was implemented within the framework of a one-dimensional radiation-transport code. After empirical calibration, the RIK simulations reproduce the observed yield trends, largely as a result of ion diffusion and the depletion of the reacting tail ions.United States. Dept. of Energy (Grant DE-NA0001857)United States. Dept. of Energy (Grant DE-FC52-08NA28752)University of Rochester. Fusion Science Center (5-24431)National Laser User’s Facility (DE-NA0002035)University of Rochester. Laboratory for Laser Energetics (415935-G)Lawrence Livermore National Laboratory (B597367

    Rapid Transcriptional Pulsing Dynamics of High Expressing Retroviral Transgenes in Embryonic Stem Cells

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    Single cell imaging studies suggest that transcription is not continuous and occurs as discrete pulses of gene activity. To study mechanisms by which retroviral transgenes can transcribe to high levels, we used the MS2 system to visualize transcriptional dynamics of high expressing proviral integration sites in embryonic stem (ES) cells. We established two ES cell lines each bearing a single copy, self-inactivating retroviral vector with a strong ubiquitous human EF1α gene promoter directing expression of mRFP fused to an MS2-stem-loop array. Transfection of MS2-EGFP generated EGFP focal dots bound to the mRFP-MS2 stem loop mRNA. These transcription foci colocalized with the transgene integration site detected by immunoFISH. Live tracking of single cells for 20 minutes detected EGFP focal dots that displayed frequent and rapid fluctuations in transcription over periods as short as 25 seconds. Similarly rapid fluctuations were detected from focal doublet signals that colocalized with replicated proviral integration sites by immunoFISH, consistent with transcriptional pulses from sister chromatids. We concluded that retroviral transgenes experience rapid transcriptional pulses in clonal ES cell lines that exhibit high level expression. These events are directed by a constitutive housekeeping gene promoter and may provide precedence for rapid transcriptional pulsing at endogenous genes in mammalian stem cells
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