6,654 research outputs found

    Effect of Interaction between Bridge Piers on Local Scouring in Cohesive Soils

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    Local scour at the piers is one of the main reasons of bridge foundation undermining. Earlier research studies focused mainly on the scour at a single bridge pier; nevertheless, modern designs of the bridges comprise wide-span and thus group of piers rather than a single pier are usually used to support the superstructure. The flow and scour pattern around group of piers is different from the case of a single pier due to the interaction effect. Reviewing the literature of local scour around bridge piers group revealed that the local scour around bridge piers group founded in cohesive soil bed was not investigated, and most of the scour studies were related to scour in cohesionless soils. The objective of the present study is to investigate the effect of the interaction between two in-line (tandem) circular bridge piers of variable spacings founded in cohesive soil on the local scour. A set of laboratory flume experiments were conducted under the clear-water scour condition to investigate this effect. This study is the first that investigates experimentally the scour around group of bridge piers in cohesive bed. It was found that the maximum scour depth at the upstream pier of the two in-line piers occurred at a spacing of two times the diameter of the pier, scour at the downstream pier was reduced due to a sheltering effect, the interference effect will be reduced for pier spacings larger than three times of the pier diameter. A recent pier scour equation was used to estimate the scour depths at the two in-line piers in cohesive soil and compare the estimated value with the measured scour depths in the laboratory. The comparison indicated that the proposed scour equation overestimates the scour depths at both the upstream and the downstream pier

    Input significance analysis: feature selection through synaptic weights manipulation for EFuNNs classifier

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    This work is interested in ISA methods that can manipulate synaptic weights namelyConnection Weights (CW) and Garson’s Algorithm (GA) and the classifier selected isEvolving Fuzzy Neural Networks (EFuNNs). Firstly, it test FS method on a dataset selectedfrom the UCI Machine Learning Repository and executed in an online environment, recordthe results and compared with the results that used original and ranked data from the previouswork. This is to identify whether FS can contribute to improved results and which of the ISAmethods mentioned above that work well with FS, i.e. give the best results. Secondly, to attestthe FS results by using a differently selected dataset taken from the same source and in thesame environment. The results are promising when FS is applied, some efficiency andaccuracy are noticeable compared to the original and ranked data.Keywords: feature selection; feature ranking; input significance analysis; evolvingconnectionist systems; evolving fuzzy neural network; connection weights; Garson’salgorithm

    Preparation and Study Hardness and Thermal Conductivity (Tc) to Polyester Resin Composite with (Titanium Dioxide, Zinc Oxide, Acrylonitril, Wood Flour Coconut

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    This study is attempt to improve thermal isolation through measuring thermal conductivity composite of on polyester resin with fillers of (TiO2, ZnO, Acrylonitril, wood flour Coconut (Wf). The grain size of the fillers is 200 µm. The number of samples is (16) in addition to the virgin sample; these samples are prepared by cast molding method for polyester with filler volume fractions (5%, 10%, 15% and 20%). Shore hardness tests were used to measure the hardness and Lee disk method for thermal conductivity. The experimental results showed that the (20% ZnO) sample has the maximum value of thermal conductivity where (20% w.f) has minimum thermal conductivity .on the other hand (15% ZnO) sample give the maximum value of hardness where (20% w.f) sample gave the minimum value of hardness. From this study there is an important factor that should be observed that is the relationship between hardness and thermal conductivity. The study prove that the experimental results satisfy the theoretical assumptions in that the additive material (fillers) of metals base increase thermal conductivity where the material of cellulose base decrease the thermal conductivity and give good thermal isolation but with low hardness and all the result above the refry sample

    The Geochemical Distribution and Assessment of Heavy metals Pollutions in Soil Sediment of Chamchamal City-Sulaimanya Governorate / NortherEastern Iraq.

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    The current study aims at the geochemical distribution of heavy elements in soil sediments.It assesses environmental pollution using pollution index and potential health hazards in the city of Chamchamal  northeastern Iraq. Twenty-one samples of soil sediments were collected in the area of residential, commercial and industrial areas in mid-July 2017. Heavy metals (As, Cu, Cr, Cd, Co, Fe, Mn, Mo, Ni, Pb, Zn) were analyzed using ICP-MS. The results showed that arsenic, chromium, cadmium, cobalt, manganese and nickel were the highest concentration in residential areas.While molybdenum and lead were higher in commercial areas, wheras copper, iron and zinc recorded the highest concentration in industrial areas. The results of pollution indicators (Igeo) showed that the  arsenic was the  (Moderately contaminated), The values of the (EF) index of the arsenic  are (Significant enrichment), the cadmium and nickel were (moderate enrichment), and the values of Cdeg showed that some of  samples are (Contamination Moderate) wheras the rest of the sites are considered (Contaminated) by  heavy metals studied. The PRI values indicated that some models were of (Riskable) and others (Very High Risk). key words: chemchmal area, heavy metal, pollution , health ris

    Modulation of Gene Expression During Stages of Liver Colonization by Pancreatic Cancer in a Rat Model

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    Pancreatic ductal adenocarcinoma (PDAC) is known for its early spreading of tumor cells into the liver. The aim of this study was to investigate the modulated gene expression of PDAC cells during liver colonization. To that purpose, ASML rat pancreatic cancer cells marked with enhanced green fluorescent protein were inoculated into the portal vein of isogenic BDX rats and reisolated from livers by fluorescence-activated cell sorting sorting at early (1, 3 days), intermediate (9 days), advanced (15 days), and terminal (21 days) stages of liver colonization. Reisolated ASML cells were used for total RNA isolation and subsequently their gene expression was investigated by Illumina chip array for mRNA and miRNA species, followed by Ingenuity Pathway Analysis (IPA). Following reisolation, 7–20% of genes and 10% of miRNA species were modulated significantly in expression during the early stage of liver colonization and continuously thereafter. These overall changes led to distinguish certain categories and processes participating in cancer progression. The knowledge of these alterations in gene expression will suggest targets, which could be used for new diagnostic procedures as well as for combating liver metastasis successfully

    Input significance analysis: feature ranking through synaptic weights manipulation for ANNS-based classifiers

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    Due to the ANNs architecture, the ISA methods that can manipulate synaptic weights selectedare Connection Weights (CW) and Garson’s Algorithm (GA). The ANNs-based classifiers thatcan provide such manipulation are Multi-Layer Perceptron (MLP) and Evolving Fuzzy NeuralNetworks (EFuNNs). The goals for this work are firstly to identify which of the twoclassifiers works best with the filtered/ranked data, secondly is to test the FR method by usinga selected dataset taken from the UCI Machine Learning Repository and in an onlineenvironment and lastly to attest the FR results by using another selected dataset taken fromthe same source and in the same environment. There are three groups of experimentsconducted to accomplish these goals. The results are promising when FR is applied, someefficiency and accuracy are noticeable compared to the original data.Keywords: artificial neural networks, input significance analysis; feature selection; featureranking; connection weights; Garson’s algorithm; multi-layer perceptron; evolving fuzzyneural networks

    Generalized Uniqueness Theorem for Ordinary Differential Equations in Banach Spaces

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    We consider nonlinear ordinary differential equations in Banach spaces. Uniqueness criterion for the Cauchy problem is given when any of the standard dissipative-type conditions does apply. A similar scalar result has been studied by Majorana (1991). Useful examples of reflexive Banach spaces whose positive cones have empty interior has been given as well

    In-vitro application of a qatari burkholderia cepacia strain (QBC03) in the biocontrol of mycotoxigenic fungi and in the reduction of ochratoxin a biosynthesis by aspergillus carbonarius

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    Mycotoxins are secondary metabolites produced by certain filamentous fungi, causing human and animal health issues upon the ingestion of contaminated food and feed. Among the safest approaches to the control of mycotoxigenic fungi and mycotoxin detoxification is the application of microbial biocontrol agents. Burkholderia cepacia is known for producing metabolites active against a broad number of pathogenic fungi. In this study, the antifungal potential of a Qatari strain of Burkholderia cepacia (QBC03) was explored. QBC03 exhibited antifungal activity against a wide range of mycotoxigenic, as well as phytopathogenic, fungal genera and species. The QBC03 culture supernatant significantly inhibited the growth of Aspergillus carbonarius, Fusarium culmorum and Penicillium verrucosum in PDA medium, as well as A. carbonarius and P. verrucosum biomass in PDB medium. The QBC03 culture supernatant was found to dramatically reduce the synthesis of ochratoxin A (OTA) by A. carbonarius, in addition to inducing mycelia malformation. The antifungal activity of QBC03’s culture extract was retained following thermal treatment at 100 °C for 30 min. The findings of the present study advocate that QBC03 is a suitable biocontrol agent against toxigenic fungi, due to the inhibitory activity of its thermostable metabolites. View Full-TextFunding: Qatar National Research Fund (a member of Qatar Foundation) under National Priorities Research Program (NPRP) grant #NPRP8-392-4-003.Scopu
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