74 research outputs found

    Persamaan Korelasi Sifat Mekanik Beton Mutu Tinggi Dengan Agregat Alami Dan Slag Nikel

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    . Beton merupakan material konstruksi bangunan yang sering digunakan karena mudah pada waktu pelaksanaan konstruksi dan biaya pemeliharaan yang relatif murah dibandingkan material lainnya. Dengan maraknya pembangunan dimana aspek lingkungan harus diperhatikan, maka agregat kasar dan halus yang berasal dari sumber daya alam sebaiknya dibatasi, bila memungkinkan diganti dengan agregat produk limbah dari industri. Perkembangan ilmu pengetahuan di bidang teknologi beton memungkinkan penggunaan limbah menjadi bahan dasar pembentuk beton, sehingga di satu sisi penggunaan bahan alam yang merusak lingkungan dapat diatasi dan di sisi lain bahan limbah dimanfaatkan seoptimal mungkin untuk bahan dasar pembentuk beton. Dalam setiap minggu, PT. INCO menghasilkan limbah padat berupa terak nikel dalam jumlah relatif besar, yaitu 77.441 ton. Sehingga dapat dilakukan penelitian mengenai penggunaan limbah padat tersebut sebagai bahan dasar pembentuk beton, baik sebagai agregat kasar maupun halus. Tujuan utama penelitian ini adalah untuk mendapatkan persamaan korelasi sifat mekanik beton kinerja tinggi (high performance concrete) dengan agregat alami dan slag nikel. Terhadap seluruh bahan pembentuk beton dilakukan pengujian mengikuti standar ASTM. Bahan dasar pembentuknya terdiri dari semen, agregat kasar, agregat halus, air dan bahan tambahan lainnya. Semua pengujian sifat mekanik beton juga mengikuti standar ASTM dan dilakukan untuk umur beton 3, 7, 14, 21, 28 dan 56 hari dengan masing-masing umur sebanyak tiga sampel. Seluruh data hasil penelitian yang telah diperoleh dilakukan analisis regresi nonlinier. Selanjutnya dibahas berbagai model korelasi sifat mekanik beton yang telah diuji. Berdasarkan analisis model korelasi diperoleh bentuk persamaan sebagai berikut :y = abttcfc28 , dimana untuk :Kuat tekan beton : a = 0,389 b = 0,996 c = 0,323Modulus elastisitas : a = 353 b = 1,001 c = 0,083Kuat tarik tidak langsung : a = 0,03 b = 1,002 c = 0,115Kuat lentur : a = 0,052 b = 0,998 c = 0,224Adapun kelebihan persamaan korelasi yang diusulkan dibandingkan persamaan dalam peraturan yang ada adalah dapat menganalisis sifat mekanik beton kinerja tinggi berdasarkan fungsi waktu 0 < t ≤ 56 dan mempunyai nilai standar error yang lebih kecil. Abstrack. Concrete is construction material of building that is often is applied by easy to when realization of construction and maintenance cost that is cheap relative compared to other material. With the hoisterous of development where environmental aspect to paid attention, hence fine and coarse aggregate coming from natural resources better be limited, if possible is changed with waste product aggregate from industry. Development of science in concrete technology area enables USAge of waste becomes concrete former base material, so that in one USAge sides of nature material destroying area can be overcome and on the other side waste material is exploited as optimal as possible for concrete former base material. In each week, PT. INCO yields solid waste in the form ofnickel slag in number relative big, that is 77.441 tons. So can be done research about USAge of the solid waste as component of concrete former basis, either as fine and coarse aggregate. Purpose of principal of this research is to get correlation equation of high performance concrete with natural aggregate and nickel slag. To all concrete former material is done assaying to follow ASTM standard. Its the former base material consisted of cements, coarse aggregate, fine aggregate, water and other admixture. All assayings of concrete mechanical property also follows ASTM standard and done for concrete age 3, 7, 14, 21, 28 and 56 days, in which three sample specimens were tested for each age. All research result data which has been obtained done by regression analysis nonlinier. Here in after is studied various correlation models of concrete mechanical property which has been tested. Based on correlation model analysis is obtained form of equation as follows : y = abttcfc28, where for :1. Compressive strength : a = 0,389 b = 0,996 c = 0,323 2. Modulus of elasticity : a = 353 b = 1,001 c = 0,083 3. Indirect tensile strength : a = 0,03 b = 1,002 c = 0,1154. Modulus of Rupture : a = 0,052 b = 0,998 c = 0,224 The advantage of this correlation equation over the standard equation is the ability to analyze the mechanical properties of high performance concrete by function of time 0 < t ≤ 56 and has a smaller standard erro

    Allelomimesis as universal clustering mechanism for complex adaptive systems

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    Animal and human clusters are complex adaptive systems and many are organized in cluster sizes ss that obey the frequency-distribution D(s)sτD(s)\propto s^{-\tau}. Exponent τ\tau describes the relative abundance of the cluster sizes in a given system. Data analyses have revealed that real-world clusters exhibit a broad spectrum of τ\tau-values, 0.7(tuna fish schools)τ2.95(galaxies)0.7\textrm{(tuna fish schools)}\leq\tau\leq 2.95\textrm{(galaxies)}. We show that allelomimesis is a fundamental mechanism for adaptation that accurately explains why a broad spectrum of τ\tau-values is observed in animate, human and inanimate cluster systems. Previous mathematical models could not account for the phenomenon. They are hampered by details and apply only to specific systems such as cities, business firms or gene family sizes. Allelomimesis is the tendency of an individual to imitate the actions of its neighbors and two cluster systems yield different τ\tau values if their component agents display different allelomimetic tendencies. We demonstrate that allelomimetic adaptation are of three general types: blind copying, information-use copying, and non-copying. Allelomimetic adaptation also points to the existence of a stable cluster size consisting of three interacting individuals.Comment: 8 pages, 5 figures, 2 table

    Immunodiagnosis of Neurocysticercosis: Ways to Focus on the Challenge

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    Neurocysticercosis (NCC) is a disease of the central nervous system that is considered a public health problem in endemic areas. The definitive diagnosis of this disease is made using a combination of tools that include imaging of the brain and immunodiagnostic tests, but the facilities for performing them are usually not available in endemic areas. The immunodiagnosis of NCC is a useful tool that can provide important information on whether a patient is infected or not, but it presents many drawbacks as not all infected patients can be detected. These tests rely on purified or semipurified antigens that are sometimes difficult to prepare. Recent efforts have focused on the production of recombinant or synthetic antigens for the immunodiagnosis of NCC and interesting studies propose the use of new elements as nanobodies for diagnostic purposes. However, an immunodiagnostic test that can be considered as “gold standard” has not been developed so far. The complex nature of cysticercotic disease and the simplicity of common immunological assumptions involved explain the low scores and reproducibility of immunotests in the diagnosis of NCC. Here, the most important efforts for developing an immunodiagnostic test of NCC are listed and discussed. A more punctilious strategy based on the design of panels of confirmed positive and negative samples, the use of blind tests, and a worldwide effort is proposed in order to develop an immunodiagnostic test that can provide comparable results. The identification of a set of specific and representative antigens of T. solium and a thorough compilation of the many forms of antibody response of humans to the many forms of T. solium disease are also stressed as necessary

    Draft genome sequence of multidrug-resistant vibrio parahaemolyticus strain PH698, infecting penaeid shrimp in the Philippines

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    The emergence of multidrug-resistant bacterial strains in diverse settings has been reported globally. In the Philippine shrimp aquaculture industry, antibiotics are used for the treatment of bacterial diseases during the production cycle. We report the draft genome of Vibrio parahaemolyticus PH698, a multidrug-resistant strain isolated from a Philippine shrimp farm

    Spatiotemporal trends in cetacean strandings and response in the southwestern Indian Ocean : 2000–2020

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    On behalf of SIF, we would like to thank the Seychelles partners (Alphonse Foundation, Desroches Foundation, Island Conservation Society, Farquhar Foundation, Seychelles Islands Foundation, Silhouette Foundation) for providing financial support to acquire and grant use of their data. Collection of data in Reunion was funded by DEAL Reunion and Region-Reunion.The south-western Indian Ocean (SWIO) is a region of global importance for marine mammal biodiversity, but our understanding of most of the species and populations found there is still rudimentary. The Indian Ocean Network for Cetacean Research (IndoCet) was formed in 2014 and is dedicated to the research of all cetacean species across the SWIO. Since 2019, there have been efforts to create a regional network for coordinated response to stranding events as well as training and capacity building in the SWIO region. The present analysis represents a first investigation of stranding data collected by various members and collaborators within the IndoCet network, covering over 14,800km of coastline belonging to nine countries/territories. Between 2000–2020, there were 397 stranding events, representing 1,232 individual animals, 17 genera and 27 species, belonging to six families: four balaenopterids, one balaenid, one physeterid, two kogiids, six ziphiids and 14 delphinids. Seven mass strandings were recorded: two were composed of three to 20 individuals and five composed of > 20 individuals. Spatial analysis of stranding events indicated that local spatio-temporal clusters (excessive number of events in time and geographic space) were present in all countries/territories, except for the Comoros. The only significant cluster was detected on the southwest coast of Mauritius, just west of the village of Souillac. The SWIO region predominantly comprises relatively poor countries/territories, but imminent Ocean Economy developments are prevalent throughout the region. This study highlights the importance of establishing baselines upon which any future potential impact from anthropogenic developments in the region can be measured.Peer reviewe

    Applying polygenic risk scoring for psychiatric disorders to a large family with bipolar disorder and major depressive disorder

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    Psychiatric disorders are thought to have a complex genetic pathology consisting of interplay of common and rare variation. Traditionally, pedigrees are used to shed light on the latter only, while here we discuss the application of polygenic risk scores to also highlight patterns of common genetic risk. We analyze polygenic risk scores for psychiatric disorders in a large pedigree (n similar to 260) in which 30% of family members suffer from major depressive disorder or bipolar disorder. Studying patterns of assortative mating and anticipation, it appears increased polygenic risk is contributed by affected individuals who married into the family, resulting in an increasing genetic risk over generations. This may explain the observation of anticipation in mood disorders, whereby onset is earlier and the severity increases over the generations of a family. Joint analyses of rare and common variation may be a powerful way to understand the familial genetics of psychiatric disorders

    Self-organized queuing and scale-free behavior in real escape panic

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    Numerical investigations of escape panic of confined pedestrians have revealed interesting dynamical features such as pedestrian arch formation around an exit, disruptive interference, self-organized queuing, and scale-free behavior. However, these predictions have remained unverified because escape panic experiments with real systems are difficult to perform. For mice escaping out of a water pool, we found that for a critical sampling rate the escape behavior exhibits the predicted features even at short observation times. The mice escaped via an exit in bursts of different sizes that obey exponential and (truncated) power-law distributions depending on exit width. Oversampling or undersampling the mouse escape rate prevents the observation of the predicted features. Real systems are normally subject to unavoidable constraints arising from occupancy rate, pedestrian exhaustion, and nonrigidity of pedestrian bodies. The effect of these constraints on the dynamics of real escape panic is also studied

    Thermal diffusion of Kerr nanobead under a tightly-focused laser beam

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    We investigated thermal diffusion of Kerr nanobead under a tightly-focused laser beam. Kerr nanobeads refer to small beads whose refractive index is governed by n2=n2(0)+n2(1)│E*E│; where n2(0)is the linear component of the refractive index, n2(1)is the nonlinear component, and │E*E│ is the intensity of linearly-polarized laser beam. Thermal fluctuation of the surrounding medium (water in this case) of the optical trap is apparent when the bead radius is appreciably small near the nanometric order. Theoretical model of three dimensional motion of Kerr nanobead under water appropriates the use of Langevin equation to account for both Brownian force and radiation force experienced by a Kerrnanobead. Diffusion of 30 nm sized dielectric bead requires 3.1 kbT (T=300K) of total energy to confine a Kerr nanobead within 0.4 um from the central optical trap based from the probability density calculations. With this confinement, Kerr nanobead can be an alternative probe handler for photonic force microscope imaging hollow microbiological structures. © International Federation for Medical and Biological Engineering 2007
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