173 research outputs found

    Top Bar Effects in Prestressed Concrete Piles

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    The top bar effect in reinforced concrete is a widely recognized phenomenon. Currently, the ACI Building Code prescribes a 30% increase in the development length of top cast reinforcing bars. No such provision is required for strands in prestressed concrete members. In this paper, the top bar effect for prestressing strands is introduced. Parameters affecting top bar phenomena in prestressed concrete piles are identified, and strategies for reducing this effect are presented. Finally, for the first time, the application of a top bar effect factor for prestressed concrete development length calculations, similar to the one applied in reinforced concrete structural elements, is proposed

    A modified multiview video streaming system using 3-tier architecture

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    In this paper, we present a modified inter-view prediction Multiview Video Coding (MVC) scheme from the perspective of viewer's interactivity. When a viewer requests some view(s), our scheme leads to lower transmission bit-rate. We develop an interactive multiview video streaming system exploiting that modified MVC scheme. Conventional interactive multiview video systems require high bandwidth due to redundant data being transferred. With real data test sequences, clear improvements are shown using the proposed interactive multiview video system compared to competing ones in terms of the average transmission bit-rate and storage size of the decoded (i.e., transferred) data with comparable rate-distortion

    Optimization of strip-layout using graph-theoretic methodology for stamping operations on progressive die: a case study

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    The design of the progressive die stamping process is optimized through minimizing the number of die stamping stations in the strip layout to reduce the die cost. In order to accomplish such end, in this study, a graph-theoretic based method is implemented to model and optimize the strip layout design. This method starts with mapping stamping features into stamping operations. This step is followed by constructing two graphs to model the precedence and adjacency constraints among stamping operations based on a set of manufacturing rules. These two graphs are called: operation precedence graph and operation adjacency graph. In the next step, a topological sorting algorithm clusters the operations into partially ordered sets. Then, a graph coloring algorithm clusters the partially ordered operations sets into final sequence of operations. The graph-theoretic technique has been implemented on a part currently manufactured by laser cutting process technology in some Egyptian factory in Cairo. This study indicated that the graph-theoretic technique offers several advantages including the ease of programming and transparency in understanding the obtained strip layout design. This is besides being a systematic and logically approach to obtain an optimized strip layout design. In general, the progressive die manufacturing can increase productivity of sheet metal works in Egypt, only in situations of mass production. The limitation is that it requires considerable skill level and training for labor to conduct die strip layout design

    New Polymer Syntheses Part: 55#. Novel Conducting Arylidene Polymers and Copolymers Based on Methyl-Cyclohexanone Moiety

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    A new interesting class of conducting polymers based on methyl-cyclohexanone in the polymer main chain has been synthesized by solution polycondensation of terephthalaldehyde with methyl-cyclohexanone. Copolymers containing different cycloalkanone moieties were also synthesized using solution polycondensation technique. The model compound I was synthesized by the interaction of methyl-cyclohexanone monomer with benzaldehyde, and its structure was confirmed by elemental and spectral analyses. The resulting new polymers and copolymers were characterized by elemental and spectral analyses, beside solubility and viscometry measurements. The thermal properties of those polymer and copolymers were evaluated by TGA, DrTGA and DTA measurements and correlated to their structural units. PDT as well as T10 was in the range from 205 to 370 ºC. In addition, T10 thermal stability for all the polymers was in theorder: VI> II > III > IV > V. X–ray analysis showed that it has some degree of crystallinity in the region 2q = 5–60 degree.The UV– visible spectra of some selected polymers were measured in DMSO solution and showed absorption bands in the range 265-397 nm, due to n – π* and π – π* transition. The morphological properties of copolymer IV as selected examples were tested by SEM. The electrical conductivities of the synthesized polymers and copolymers enhanced to become in the range of 10-9-10-8 S cm-1 by doping with iodine

    Evaluation of health-related quality of life and muscular strength in children with beta thalassemia major

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    Background: Thalassemia is an inherited blood disorder that requires repeated blood transfusions and chelation regimes. This may lead to restrictions in physical activities, social participation as well as decreased muscle strength.Aim: The aim of this study was to evaluate the health-related quality of life (HRQoL), muscular strength and pain in children with β-thalassemia major.Patients and method: One hundred and twenty children (60 with β-thalassemia major and 60 age-matched healthy) were participated in a cross-sectional study from both sexes (57 girls and 63 boys) with ages ranging from two to twelve years. HRQoL (physical, emotional, social and school functioning), muscular strength and pain were evaluated for all children by using the pediatric quality of life inventoryTM (PedsQLTM) 4.0 generic core scale, hand-held dynamometer and visual analogue scale (VAS) respectively.Results: Children with β-thalassemia major showed a significant decrease in all domains of health-related quality of life and handgrip strength with a significant increase in VAS score (p ≤ 0.0001).Conclusions: The study concluded that thalassemia as a chronic disease has a negative impact on HRQoL and muscle strength of children in different age group.Keywords: Beta thalassemia, Quality of life, Handgrip strength, childre

    Information-Theoretic Bounds for Steganography in Multimedia

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    Steganography in multimedia aims to embed secret data into an innocent looking multimedia cover object. This embedding introduces some distortion to the cover object and produces a corresponding stego object. The embedding distortion is measured by a cost function that determines the detection probability of the existence of the embedded secret data. A cost function related to the maximum embedding rate is typically employed to evaluate a steganographic system. In addition, the distribution of multimedia sources follows the Gibbs distribution which is a complex statistical model that restricts analysis. Thus, previous multimedia steganographic approaches either assume a relaxed distribution or presume a proposition on the maximum embedding rate and then try to prove it is correct. Conversely, this paper introduces an analytic approach to determining the maximum embedding rate in multimedia cover objects through a constrained optimization problem concerning the relationship between the maximum embedding rate and the probability of detection by any steganographic detector. The KL-divergence between the distributions for the cover and stego objects is used as the cost function as it upper bounds the performance of the optimal steganographic detector. An equivalence between the Gibbs and correlated-multivariate-quantized-Gaussian distributions is established to solve this optimization problem. The solution provides an analytic form for the maximum embedding rate in terms of the WrightOmega function. Moreover, it is proven that the maximum embedding rate is in agreement with the commonly used Square Root Law (SRL) for steganography, but the solution presented here is more accurate. Finally, the theoretical results obtained are verified experimentally.Comment: arXiv admin note: substantial text overlap with arXiv:2111.0496

    MicroRNA-34a: A Key Regulator in the Hallmarks of Renal Cell Carcinoma

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    Renal cell carcinoma (RCC) incidence has increased over the past two decades. Recent studies reported microRNAs as promising biomarkers for early cancer detection, accurate prognosis, and molecular targets for future treatment. This study aimed to evaluate the expression levels of miR-34a and 11 of its bioinformatically selected target genes and proteins to test their potential dysregulation in RCC. Quantitative real-time PCR for miR-34a and its targets; MET oncogene; gene-regulating apoptosis (TP53INP2 and DFFA); cell proliferation (E2F3); and cell differentiation (SOX2 and TGFB3) as well as immunohistochemical assay for VEGFA, TP53, Bcl2, TGFB1, and Ki67 protein expression have been performed in 85 FFPE RCC tumor specimens. Clinicopathological parameter correlation and in silico network analysis have also implicated. We found RCC tissues displayed significantly higher miR-34a expression level than their corresponding noncancerous tissues, particularly in chromophobic subtype. MET and E2F3 were significantly upregulated, while TP53INP2 and SOX2 were downregulated. ROC analysis showed high diagnostic performance of miR-34a (AUC = 0.854), MET (AUC = 0.765), and E2F3 (AUC = 0.761). The advanced pathological grade was associated with strong TGFB1, VEGFA, and Ki67 protein expression and absent Tp53 staining. These findings indicate miR-34a along with its putative target genes could play a role in RCC tumorigenesis and progression

    Development of Mouse Hepatocyte Lines Permissive for Hepatitis C Virus (HCV)

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    The lack of a suitable small animal model for the analysis of hepatitis C virus (HCV) infection has hampered elucidation of the HCV life cycle and the development of both protective and therapeutic strategies against HCV infection. Human and mouse harbor a comparable system for antiviral type I interferon (IFN) induction and amplification, which regulates viral infection and replication. Using hepatocytes from knockout (ko) mice, we determined the critical step of the IFN-inducing/amplification pathways regulating HCV replication in mouse. The results infer that interferon-beta promoter stimulator (IPS-1) or interferon A receptor (IFNAR) were a crucial barrier to HCV replication in mouse hepatocytes. Although both IFNARko and IPS-1ko hepatocytes showed a reduced induction of type I interferons in response to viral infection, only IPS-1-/- cells circumvented cell death from HCV cytopathic effect and significantly improved J6JFH1 replication, suggesting IPS-1 to be a key player regulating HCV replication in mouse hepatocytes. We then established mouse hepatocyte lines lacking IPS-1 or IFNAR through immortalization with SV40T antigen. Expression of human (h)CD81 on these hepatocyte lines rendered both lines HCVcc-permissive. We also found that the chimeric J6JFH1 construct, having the structure region from J6 isolate enhanced HCV replication in mouse hepatocytes rather than the full length original JFH1 construct, a new finding that suggests the possible role of the HCV structural region in HCV replication. This is the first report on the entry and replication of HCV infectious particles in mouse hepatocytes. These mouse hepatocyte lines will facilitate establishing a mouse HCV infection model with multifarious applications

    Sinteza i protuupalno, analgetsko i ulcerogeno djelovanje derivata tieno[2,3-d]pirimidina

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    5-Methyl-6-phenyl-2-thioxothieno[2,3-d]pyrimidone derivative (2) reacted with hydrazonoyl chloride derivatives to afford triazolothienopyrimidones 4a-f. Also, acetone-1-(2-amino-5-isopropyl-thiophene-3-carbonitrile) (3) reacted with functional and bifunctional groups to yield the corresponding compounds 5-11. The new products showed anti-inflammatory, analgesic, and ulcerogenic activities comparable to that of indomethacin and acetylsalicylic acid, respectively.Reakcijom derivata 5-metil-6-fenil-2-tioksotieno[2,3-d]pirimidona (2) s hidrazonoil kloridima dobiveni su triazolotienopirimidoni 4a-f, a reakcijom aceton-1-(2-amino-5-izopropil-tiopen-3-karbonitrila (3) s funkcionalnim i bifunkcionalnim spojevima dobiveni su produkti 511. Novi spojevi imaju slično protuupalno, analgetsko i ulcerogeno djelovanje kao i indometacin, odnosno acetilsalicilna kiselina
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