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Offshore structures include fixed, floating platforms and port decks. It is well known that more than 25% of worldwide oil and gas comes from offshore facilities. So, the stability of offshore construction is the main priority to be designed and well executed, and a long and permanent maintenance program should be scheduled. One of the offshore structures is a jacket substructure of platforms. This Jacket is a rigid steel structure that supports the deck and topsides of a continuous offshore platform. The loads subject to the offshore Jacket are dead and live loads in addition to the environmental loads. The environmental loading is mainly due to wind, current waves, and seismic activity. Environmental loads affect a percentage exceeding 35% of the total loads on the structure, the largest percentage of which is from the effect of waves. Offshore the rigs. The stability and response of the maritime structures should be studied under the effect of these types of environmental loadings. The analytical and numerical methods are used to analyze environmental forces subjected to jacket offshore structure platforms. Incremental Dynamic Analysis (IDA) was employed to analyze the linear and nonlinear dynamic response of jacket-type offshore platforms under seismic loading. The effect of the environmental loadings experienced by the jacket structures will be reviewed in this study. [ABSTRACT FROM AUTHOR]

The essential radiant heating system component is a water heater so this study presents an experimental and numerical work of a water heater with an AC heating element powered by photovoltaic panels. The experimental work included a study of the thermal performance of a water tank under a constant ambient temperature and different supplied water temperatures. The impact of ambient temperatures of (290,292, and 294) K on the tank water temperature distribution under a constant supplied water temperature of 280K had been studied. Also, the stratification of water temperature is analyzed with the height of the tank. Numerical work studied the tank water temperature distribution with time for different supplied water temperatures of (280,285 and,290) K. Experimental work results have been utilized for developing and validating the numerical work results The comparison between experimental and numerical results appears good matching and the error does not exceed 3%. [ABSTRACT FROM AUTHOR]

The phenomenon of flame propagation within cylindrical conduits, including both surfaces with minimal irregularities and those exhibiting roughness, as well as those harboring obstacles, constitutes a prominent subject of investigation within contemporary scientific inquiry. The transportation of gas fuels with varying reactivity levels in different combinations is of great significance due to their widespread utilization. The present review paper elucidates the intricate mechanism underlying the formation of tulip flames within the confines of horizontal combustion chambers. The tulip flame is a manifestation solely governed by hydrodynamics, arising from the interplay between the retrograde motion of deflected combusted gases expanding from the flanking regions of the flame and the progressive motion of unburned gases propelled forward within the finger-like structure of the flame. This intricate interplay significantly influences both the configuration and efficacy of the combustion system. Extensive research endeavors have been undertaken to explore the intricate phenomenon of flame propagation and its associated velocity. Nevertheless, the findings of these investigations have been dispersed among diverse scholarly outlets, including esteemed journals and esteemed conference proceedings. The primary aim of this manuscript is to amalgamate an extensive corpus of scientific investigations and present it in a manner conducive to critical examination. [ABSTRACT FROM AUTHOR]

Because of the need for energy growing exponentially, prices are constantly going up, which impacts both residential and business consumers. Researchers are looking for workable solutions to this problem, such as off-peak scheduling that reduces peak energy consumption while maintaining reasonable energy costs. The system design issues that regulate decision-making for the best operation management are optimized in this research using an Improved Crow Search Algorithm (ICSA). The simulation's results show that the suggested algorithm-based ICSA reduces carbon emissions, peak-to-average ratio (PAR), and electricity costs. Using the ICSA method, the scheduling controller suggested in this study was successful in achieving an energy savings of 30.58%. [ABSTRACT FROM AUTHOR]

MR dampers are attracting wide interest from researchers for their use in various fields. In this study, a review of MR models is demonstrated and investigated to show their reliability and effectiveness. The vehicle's body mass response was compared when using a passive and semi-active damper when the shock absorber was exposed to road bumps, Two types of road profile (pump,step)were used to test the response of the suspension system. The damping of the road's vibrations was improved when using the MR damper by up to 50% better than using the passive suspension. In addition, the parametric models that explain the behaviour of MR dampers are used and employed through MATLAB/Simulink environment to study and analyse the responses of the semi-active quarter-car suspension system with the MR damper. As a result, it was found that The Buoc-Wen model is one of the most accurate models in describing the behaviour of the MR damper and is suitable for numerical analysis. In contrast, the Bingham model is well formulated and is one of the simplest mathematical models of the MR damper. [ABSTRACT FROM AUTHOR]

There are many benefits and special insights to be found in the chilly ocean and marine locations of our planet. The inquiry can't be conducted without the help of professional techniques. The most important components of the collaborative network and communication frameworks are the underwater unmanned vehicles and sensor systems. Oceans and seas that are cold due to water temperature or ice cover are discussed here in terms of the acoustic correlation and journey below the surface. We summarize, evaluate, and contrast the benefits and drawbacks of several methods, including Frequency-shift keying, Phase-shift keying, Orthogonal frequency-division multiplexing, and Code-division multiple access, for use in underwater acoustic communication. The works are also analyzed in terms of their varied character and methods of implementation, and potential areas for future research are highlighted for further study. [ABSTRACT FROM AUTHOR]

The current study has focused on the construction and I-V characterization of capped CdSe schottky diode. The organized triethanol-amine (TEA) capped CdSe nanoparticles solution was deposited on two different types of substrates, aluminum (Al) substrate and fluorine tin oxide (FTO) substrate, by using the simple drop-casting deposition method. The results showed that ideality factor was equivalent to 8 and 11 for Al and FTO, respectively. Furthermore, the form and size of TEA capped-CdSe has been established by scanning electron microscope SEM. [ABSTRACT FROM AUTHOR]

Recently, thermo-electric cooling technology (TECT) had developed as one of the most low-energy-consumption and effective approaches of electronic cooling. The present research gave detailed survey regarding TECT in order to provide a thorough understanding of thermo-electric applications in the electronic cooling. The thermo-electric physical parameters, which include the thermal conductivity K, Seebeck coefficient S, and electric resistance R, are highly influenced by the temperature degrees of the thermo-electric cooling and heating sides and were simplified to constants in a case when the thermo-electric cooling model has been established theoretically. In addition, a total of two systematical solution techniques, namely, effectiveness-number of the transfer units and thermal resistance network, were developed to explain coefficient of performance (COP). The impacts of air temperature, cooling load, and all of the thermal conductance in the heating side on performance of the cooling were investigated, with surface temperature of the electronic devices and COP serving as assessment indices. According to our findings, thermal control for the high heat flux electronics might be accomplished through improving heat transfer in hot side of thermo-electric system and increasing the number of the thermo-electric coolers. Regulating parameters and modelling for the practical applications were provided, and cooling capability of thermo-electric technology for electrical devices has the potential to be developed further. [ABSTRACT FROM AUTHOR]

The development that took place in the late centuries and the growing population of the world led to an increase in the demand for light derivatives of petroleum because it is used in most industries, either as a feed material or as a fuel, as well as as a fuel for various means of transportation and for various daily human uses. Also, the percentage of extracted light oils became less and the costs of extraction and refining were high. Therefore, it became necessary to find other ways to convert heavy, low-quality, low-priced and unwanted oils into light oils of higher quality and a desirable price. Thermal cracking is one of the first and most important of these ways to upgrade heavy oils, as it will be in this review mentions the previous experiences and their operational conditions and the factors influencing when upgrading the atmospheric residue (AR). [ABSTRACT FROM AUTHOR]

This paper presents an adaptive Digital Predistorter (DPD) to handle the nonlinearity and memory challenges that effect the transmitted signal in High Power Amplifier (HPA) system. The proposed scheme first handles the nonlinearity effect by estimating the reverse error, then the obtained signal is processed by the FIR filter to diminish the memory effect. The simulation results of the proposed method present a superior performance compared with state-of-the-art methods used in compensating nonlinearity and memory effects. These results suggest that the proposed approach is more suitable to transmit a standard signal with less error by using traditional HPA. [ABSTRACT FROM AUTHOR]

The Internet of Things (IoT) is one of the most important modern technological practical sciences that contains a large number of heterogeneous devices that have the ability to communicate with each other through the Internet. Many different devices and protocols, as well as various types of technologies, participate in accomplishing this task. Information security is very difficult in this environment, which integrates with different environments especially Software-Defined Networking (SDN) is based on the Internet of Things. Unfortunately, SDN/IOT faces many security issues that affect the network components and the provided services, especially the attacks related to refusing of service DDoS attack. Alongside, to prevent consume controller resources and provide a solution to detect such attacks, the present paper proposes a method depending on DDoS attack detection plus mitigation with RYU and FloodLight controllers. The proposed method uses the Entropy-threshold technique programmed in python within the controllers and DDoS attacks executed from IoT sensors. The controller's use the entropy value to block that specific port in the switch if it falls below a given threshold value and then shut down the port. The results show that Floodlight is better than dealing with DDoS attack cases compared with the RYU controllers. Alongside, the Throughput decreased from 0.1158 KB/s to 0.08916 KB/s in the Floodlight controller, while it decreased in the RYU controller from 0.0646 KB/s to 0.03294 KB/s. [ABSTRACT FROM AUTHOR]

NBR is one of the common rubber used in oil and gas sector, automotive sector and gloves manufacturing. Conversion of solid waste Nitrile Butadiene Rubber (NBR) latex sludge into liquid can be done by using fractional distillation method. The solid waste NBR was heat above its decompose temperature to evaporate the polymer in form of vapor and will be condensed by condenser column into liquid form. The decomposed temperature of waste NBR was determined by Thermogravimetric (TGA) analyzer which is at 450 °C. The processed hydrocarbon liquid was characterized by using Carbon Nitrogen Sulphur (CNS) analyzer, and Gas Chromatography Mass Spectroscopy (GCMS) analyzer. Sulfur is the main compound exist in the waste NBR latex sludge which is 0.73670 % as it being added for vulcanization process. The carbon and nitrogen percentage are 0.17419 % and 0.16479 %. [ABSTRACT FROM AUTHOR]

Lateral and vertical ordering of InGaAs quantum dots over GaAs <001> has been achieved in earlier reports resembling an anisotropic lateral pattern. We present in this letter a method of breaking the anisotropy of such structures by changing the growth environment from As4 to As2 molecules, a method that made it possible to produce 2D lateral ordering of InGaAs QDs. Our results are consistent with reported experimental and theoretical studies on surface structure and diffusion mechanism over GaAs <001>. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Nanocomposites of organo Zn-Al layered double hydroxide (LDH) with natural rubber (SMR CV60) were successfully synthesized and characterized. To prepare the nanocomposites, a hydrophilic Zn-Al layer double hydroxide (ZnAl LDH -NO3-) was first converted into the organophilic form by using dodecylsulphate ion (DS) as a guest in Zn-Al layer double hydroxide (ZnAl LDH-DS). Intercalation of dodecylsulphate anion into the interlayer of LDH increased the surface area and the porosity of LDH. Nanocomposites of NR / ZnAl LDH-DS was then prepared by melt intercalation method using Haake internal mixer. The resulting compounds were then vulcanizated using the conventional method. X-Ray diffractogram the organophilic ZnAl-DS LDH shows the basal spacing of the ZnAl-LDH expands from 0.89 nm with nitrate as the intergallery anions to 2.53 nm due to the accommodation of DS surfactant anions. After the compounding with the natural rubber, the basal spacing of ZnAl LDH-DS in the composites is increased to 3.90 and 3.66 nm when the Zn-Al-LDH-DS contents are 1 phr and 15 phr respectively. TEM revealed the layered double hydroxide generally uniformly distributed in the rubber matrix. Further characterization indicates that the tensile strength of NR/ Zn-Al LDH-DS (nanocomposites) is higher than that of the NR/Zn-Al LDH-NO3- (macrocomposites). © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The RIBRAS (Radioactive Ion Beams Brazil) facility recently installed at the Pelletron Laboratory of the University of São Paulo consists of two superconducting solenoids used to produce and focalize beams of light radioactive nuclei, as 6He, 7Be,8Li etc. The low energy, light, radioactive beams available are used to study reactions close to the Coulomb barrier. The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier. Reaction cross sections were extracted from the optical model fits, using the São Paulo Potential (SPP). The reduced reaction cross sections of 6He on 27Al were compared to reduced reaction cross sections for other projectiles as 6,7Li, 9Be and 16O on 27Al and they are larger than those for stable projectiles by an amount similar to the calculated nuclear break-up cross section for this system. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We discuss the influence of the breakup process of weakly bound nuclei on the fusion cross section. The complete fusion for heavy targets is found to be suppressed due to the incomplete fusion following the breakup, whereas this effect is negligible for light targets. The total fusion cross sections for stable projectiles are not affected by the breakup process, whereas it is suppressed for halo projectiles. The non capture breakup is the dominant process at sub-barrier energies. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

We compare a multi-level statistical model with a two-level model for the decay out of superdeformed rotational bands in atomic nuclei. We conclude that while the models depend on different dimensionless combinations of the input parameters and differ in certain limits, they essentially agree in the cases where experimental data is currently available. The implications of this conclusion are discussed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

We study the lowest energy states of a weakly interacting trapped atomic Bose-Einstein condensate in both quantum and classical cases. An analytic expression for the ground-state wavefunction of a rotating Gross-Pitaevskii condensate of trapped atoms describes the onset of vorticity in an accelerated trap, starting from the vortex entry followed by formation of growing symmetric Wigner molecules. Within a unified picture, it explains the staircase of the angular momentum jumps and the behavior of the bosonic occupancies observed in numerical and variational studies. The similarity of this behavior and mesoscopic superconductors is discussed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Gallium oxide nanodots of 220–300 nm diameters have been grown by SiO2-assisted thermal evaporation. The grayish-white crust deposited on the crucible walls was proved to be crystalline Ga2O3 through X-ray diffraction and TEM electron diffraction. The morphology of the samples examined by SEM confirmed the nanodot structure formation of average diameter 220±30 nm and average density 1.77×108 cm-2. The absorption spectra of the Ga2O3 suspension in water revealed two absorption peaks at 329.99 nm (3.76 eV) and 338.60 nm (3.67 eV). Photoemission of blue light at room temperature was observed at 410.3 nm under excitation at 330.00±4.06 nm. The growth mechanism of the nanodots is explained by a liquid-vapor-solid mechanism. The measured remaining ingot hardness was found to be 16.6 Vickers hardness number, exceeding that of SiO2. This might well indicate the existence of a certain percentage of the hardening Ga2O3 compound in the remaining catalytic ingot. [ABSTRACT FROM AUTHOR]