126 research outputs found

    The Use of Gum Arabic Liquid and Modified Liquid in Concrete Mixes

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    In this paper, the purest kind of  Gum Arabic, extracted from (Hashab) trees (in western Sudan ), is used in concrete mixes after crushing to be in a form of powder which was dissolved in water to get the liquid of this additive. In this study, Gum Arabic liquid was added to concrete mixes at ratios of 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0 % and 1.2 % of cement content. Eleven concrete mixes were prepared: One as a control mix, seven with Gum Arabic liquid, and three with Gum Arabic liquid with modified water cement ratios added. This modification was done by reducing water cement ratios in concrete mixes to be 0.4 %, 0.6% and 0.8% of cement content. The study showed that the addition of Gum Arabic to the concrete mixes has a clear effect when equal to 0.4% of cement content. The compressive strength was measured at ages of 7, 21, and 28 days and it was found that it decreases slightly with increase in the proportion of Gum Arabic in concrete mixes. The concrete mixes prepared using modified gum Arabic in its liquid state by reducing (w/c) and adding gum Arabic as a percentage of cement content showed a clear and significant change in the properties of concrete. These ratios resulted in high compressive strength concrete with good workability. Keywords: Gum Arabic, Hashab, Sudan, compressive strength, workabilit

    IPv6 Applicability in SCADA System Network

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         The trend today is to build a secure fault tolerant Internet/Intranet connected distributed SCADA system networks using open and standard software/hardware. This paper made use of advances in Ethernet such as Fast/Gigabit Ethernet, micro-segmentation and full-duplex operation using switches, IPv6 enhanced features and TCP/IP to fulfill the real-time requirements for SCADA system network. OPNET Modeler simulator is used for modeling and simulating the network. The various measured delays showed that IPv6 introduction in such network introduces very small (negligible) delay and shows better performance on applying Quality of Service relative to IPv4. Also it is found that delays increase with increased transported packet size

    Industrial Ethernet Protocols IPv6 enabling approach

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    The current Internet Protocol (IPv4) made Ethernet with TCP/IP find application in industrial automation environment via Industrial Ethernet Protocols. The question "Can things go smooth in Internet Protocol next generation (IPv6)?". This paper answers the question by proposing solutions and proofing via simulation using OPNET Modeler simulator that IPv6 introduction in industrial automation environment introduces very small (negligible) delay relative to IPv4. Measured delays include: global Ethernet delay, IP node end-to-end delay and delay variation for 72, 520 and 1500 bytes transported packet size. Results showed that IPv6 introduces very small delay relative to IPv4, the various delays increase with increased packet size and IPv6 can be used in industrial automation environment. &nbsp

    Utilization of Landsat-8 data for the estimation of carrot and maize crop water footprint under the arid climate of Saudi Arabia

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    Understanding the spatial variability of Water Footprint (WF) of crops is essential for the efficient use of the available water resources. Therefore, this study was designed to bridge the gap in knowledge existed in the area of WF in the arid climate of Saudi Arabia by quantifying the remote sensing based blue-WF (WFblue) of maize and carrot crops cultivated during the period from December 2015 to December 2016. Agrometeorological (empirical) estimated WF components, namely, the WFblue, the green-WF (WFgreen) and the grey-WF (WFgrey), were determined at a farm scale in conjunction with the climatic conditions and cropping patterns. On the other hand, the WFBlue was estimated from Landsat-8 data using energy balance and yield models. The empirical approach based WFBlue was used as a reference for the accuracy assessment of the Landsat-8 estimated WFBlue. The empirically estimated WF of silage maize ranged from 3540 m3 t-1 to 4960 m3 t-1. Out of which the WFgreen, the WFblue and the WFgrey composed 0.74%, 83.28% and 15.98%, respectively. For the carrot crop; however, the WF ranged between 2970 m3 t-1 and 5020 m3 t-1. Where, the WFgreen, the WFblue and the WFgrey represented 0.50%, 77.31% and 22.19%, respectively. Using Landsat-8 data, the WFblue was found to vary across the crops from 2552 m3 t-1 (silage maize) to 3010 m3 t-1 (carrot). Results also revealed a highly significant linear relationship between the empirical and the Landsat-8 derived WFBlue (R2 = 0.77, P>F = 0.001). The utility of Landsat-8 data in mapping WF showed reliable seasonal estimates, which can greatly enhance precision management practices of irrigation water

    Pushover Analysis of Existing 4 Storey RC Flat Slab Building

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    A four-story residential existing reinforced concrete building in the city of Khartoum-Sudan, subjected to seismic hazard ,was analyzed. Plastic hinge is used to represent the failure mode in the beams and columns when the member yields. The pushover analysis was performed on the building using SAP2000 software (Ver.14) and equivalent static method according to UBC 97. The principles of Performance Based Seismic Engineering are used to govern the analysis, where inelastic structural analysis is combined with the seismic hazard to calculate expected seismic performance of a structure. Base shear versus tip displacement curve of the structure, called pushover curve, is an essential outcomes of pushover analysis. The pushover analysis is carried out in both positive and negative x and y directions. Default hinge properties, available in some programs based on the FEMA -356 and Applied Technology Council (ATC-40) guidelines are used for each member. One case study has been chosen for this purpose. The evaluation has proved that the four-story residential building is not seismically safe

    Actively Addressing Systemic Racism Using a Behavioral Community Approach

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    Recent police brutality and related violence against Black people, coupled with the COVID-19 pandemic, has further evidenced the disproportionate impact of systemic racism in our institutions and across society. In the United States, the alarming mortality rates for Black people due to police violence and COVID-19 related deaths are clear demonstrations of inequities within a long history of disparate outcomes. In understanding systemic racism, it is essential to consider how it is embedded within society and across socio-ecological levels. The Social-Ecological Model (SEM) is used to examine conditions within the environment that maintain systemic racism, including within our field and discipline. A behavioral-community approach for examining racism aids in determining points of intervention across multiple ecological levels that may contribute to behavior change, including with behaviorists. The science of behavior is well-suited to help examine the contingencies governing behaviors within and across systems, which is pivotal for addressing operant behaviors to influence long-term behavior change. This paper calls on the behavioral community to address systemic racism within our environments and systems of influence to contribute to a more equitable community. Systemic racism, including within the context of anti-Blackness, is examined by considering behavior change strategies that can be supported by behaviorists across socio-ecological levels. Tools for collaborative action are provided to support behaviorists in demonstrating the skills needed across a continuum of behaviors from allyship to anti-racism to actively address systemic racism

    Quantum Heat Flow Model for Heat Flow in Some Nanotubes

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    Using Schrodinger equation in a fractional medium a useful expression for heat flow through Nano tubes has been found. Fortunately, this equation resembles  that obtained by Moran Wang etal, and Hai- Dong Wang teal.   the ordinary thermal conductivity is constant. The effective thermal conductivity temperature dependent resembles that obtained for carbon Nano tubes and Boron Nitride Nano tubes. It is also finite at low temperature which also conforms with experimental data for carbon and Boron. Since Nano materials are described by quantum lows, this new model is thus more suitable for Nano tubes, as for as it is derived using quantum laws

    Analytical solutions of the space–time fractional Kadomtsev–Petviashvili equation using the (G’/G)-expansion method

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    This paper focusses on the nonlinear fractional Kadomtsev–Petviashvili (FKP) equation in space–time, employing the conformable fractional derivative (CFD) approach. The main objective of this paper is to examine the application of the (G’/G)-expansion method in order to find analytical solutions to the FKP equation. The (G’/G)-expansion method is a powerful tool for constructing traveling wave solutions of nonlinear evolution equations. However, its application to the FKP equation remains relatively unexplored. By employing traveling wave transformation, the FKP equation was transformed into an ordinary differential equation (ODE) to acquire exact wave solutions. A range of exact analytical solutions for the FKP equation is obtained. Graphical illustrations are included to elucidate the physical characteristics of the acquired solutions. To demonstrate the impact of the fractional operator on results, the acquired solutions are exhibited for different values of the fractional order α, with a comparison to their corresponding exact solutions when taking the conventional scenario where α equals 1. The results indicate that the (G’/G)-expansion method serves as an efficient method and dependable in solving the nonlinear FKP equation
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