93 research outputs found

    The Effect of Water-Cement Ratio on Sulfate Resistance of Self-Compacting Concrete with Bagasse Ash

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    Previous study showed so many factors will contribute to the durability of concrete, such as cement content, water cement ratio, admixtures to be used, compaction dan curing methods. Two types of admixtures for concrete mixture can be used, e.g. chemical admixture and mineral admixture. Materials can be categoried as mineral admixture such as fly ash, silica fume, risk husk ash, and bagasse ash. Sulfate resistance of concrete is one of the examples of chemical durability of concrete. Self-Compacting Concrete (SCC) known as concrete which can flow within its self-weight and without forming honeycombing, segregation and bleeding, even with no compaction. In this experimental work, bagasse ash was used in concrete mixture as partial replacement of cement with the percentage of 10%, 15% and 20%. The variation of w/b were used e.g 0.275, 0.300 and 0.325. For the purpose to stipulate the sulfate attack on concrete, the cylinder specimen with size of 100 x 200 mm and magnesium sulfate solution with 5% and 7% molarity were used. To observe the percentage of concrete weight loss, all the specimen were immersed in this solution within 28 days. The result showed that the value of compressive strength for the specimen with w/b = 0.275 and 15% bagasse ash was up to 67.240 MPa for 28 days and 68.096 MPa for 56 days without immersion in magnesium sulfate solution. The highest percentage of concrete weight loss is 3.030% yielded from the specimen with w/b = 0.325 and 0% bagasse ash which was immersed in 7% molarity of magnesium sulfate solution

    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

    Loading capacity calculation of integrated precast slab and column panel using cold-formed steel

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    In the current study, the precast panel using a cold-formed steel section integrated with a cold-formed steel section integrated with self-compacting concrete was connected to the precast column panel. A T-shaped plate was used as a joint connector. Point loading applied onto the free-side of the slab panel. The material used to form a composite slab panel was C12524-type of cold-formed steel section as the reinforcements and it was integrated with self-compacting concrete. The connection in this research was divided into two-part. It was the side part and the middle part. The quality of cold-formed steel was fy = 530 MPa and fu = 590 MPa, the quality of the T-shaped plate connector grade was S355. The bolt diameter was variated with 10 mm, 12 mm, 14 mm, and 16 mm. The bolt quality was grade 8.8 (fy = 800 MPa). The calculation was the moment joint capacity of the connection and the stiffness. The moment joint capacity was increased within the bolt diameter increased. The side part of the specimen had the highest stiffness value; the bolts that could be used were M10, M12, and M14. To use the M16 bolt, configure the bolt spacing to be compatible with the standard BS EN 1-8:2005 [1]

    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

    XMM-Newton and optical follow-up observations of three new polars from the Sloan Digital Sky Survey

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    We report follow-up XMM-Newton and optical observations of three new polars found in the Sloan Digital Sky Survey. Simple modeling of the X-ray spectra, and consideration of the details of the X-ray and optical lightcurves corroborate the polar nature of these three systems and provide further insights into their accretion characteristics. During the XMM-Newton observation of SDSS J072910.68+365838.3, X-rays are undetected apart from a probable flare event, during which we find both the typical hard X-ray bremsstrahlung component and a very strong line O VII (E=0.57 keV), but no evidence of a soft blackbody contribution. In SDSS J075240.45+362823.2 we identify an X-ray eclipse at the beginning of the observation, roughly in phase with the primary minimum of the optical broad band curve. The X-ray spectra require the presence of both hard and soft X-ray components, with their luminosity ratio consistent with that found in other recent XMM-Newton results on polars. Lastly, SDSS J170053.30+400357.6 appears optically as a very typical polar, however its large amplitude optical modulation is 180 degrees out of phase with the variation in our short X-ray lightcurve.Comment: 9 pages, 9 figures, accepted for publication in the ApJ (January 2005

    Factorial and Economic Evaluation of an Aqueous Two-Phase Partitioning Pilot Plant for Invertase Recovery From Spent Brewery Yeast

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    Aqueous two-phase systems (ATPS) have been reported as an attractive biocompatible extraction system for recovery and purification of biological products. In this work, the implementation, characterization, and optimization (operational and economic) of invertase extraction from spent brewery yeast in a semi-automatized pilot plant using ATPS is reported. Gentian violet was used as tracer for the selection of phase composition through phase entrainment minimization. Yeast suspension was chosen as a complex cell matrix model for the recovery of the industrial relevant enzyme invertase. Flow rates of phases did not have an effect, given that a bottom continuous phase is given, while load of sample and number of agitators improved the recovery of the enzyme. The best combination of factors reached a recovery of 129.35 ± 2.76% and a purification factor of 4.98 ± 1.10 in the bottom phase of a PEG-Phosphate system, also resulting in the removal of inhibitor molecules increasing invertase activity as reported by several other authors. Then, an economic analysis was performed to study the production cost of invertase analyzing only the significant parameters for production. Results indicate that the parameters being analyzed only affect the production cost per enzymatic unit, while variations in the cost per batch are not significant. Moreover, only the sample load is significant, which, combined with operational optimization results, gives the same optimal result for operation, maximizing recovery yield (15% of sample load and 1 static mixer). Overall res ults of these case studies show continuous pilot-scale ATPS as a viable and reproducible extraction/purification system for high added-value biological compounds

    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
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