1,272 research outputs found

    Synthesis of Glycine, Methyl Ester Hydrochloride from Formaldehyde

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    Formaldehyde was made into Glycine, methyl ester in a three step synthesis. First, formaldehyde was hydrolyzed with dilute potassium cyanide and acetic acid to form methylene-amino acetonitrile. The nitrile was then hydrolyzed with barium hydroxide, and boiled with norit to produce glycine. Finally, the glycine was then allowed to react with sulfuric acid and thionyl chloride to produce glycine, methyl ester. After each step, the product was purified using recrystallization, and was identified using IR, NMR, and melting point. Green chemistry practices were implemented in this procedure to conserve atom economy. Typically, nitriles are hydrolyzed using hydrochloric acid; however the product becomes very difficult to separate and low yields are common. When the hydrochloric acid is replaced with barium hydroxide a significantly higher yield is produced. In addition, hydrochloric acid can lead to photochemical smog, and can be toxic to aquatic environments, so barium hydroxide can be a better alternative. This synthesis is important because glycine, methyl ester is a precursor for creatine, which is an organic acid that is made in the body from amino acids to increase the production of ATP that can be used by the muscles

    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

    DNA computing based stream cipher for internet of things using MQTT protocol

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    Internet of Things (IoT) is a rapidly developing technology that enables “devices” to communicate and share information amongst them without human control. The devices have the features of internet connectivity and networking. Due to the increasing demands of a secure environment in IoT application, security has become a crucial aspect on which researchers have been increasingly focused. Connecting devices to the internet can facilitate intruders to attack devices as they can access the data from anywhere in the globe. In this work, an encryption–decryption process-based stream cipher has been used. The messages between IoT nodes were encrypted using One Time Pad (OTP) and DNA computing. Furthermore, the required key sequence was generated using a linear feedback shift register (LFSR) as a pseudo number key generator. This key sequence was combined to generate a unique key for each message. The algorithm was implemented using source python and tested on a Raspberry pi under Linux open operation system

    Recent Trends in Plasmonic Nanowire Solar Cells

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    Light trapping is crucial for low-cost and highly efficient nanowire (NW) solar cells (SCs). In order to increase the light absorption through the NWSCs, plasmonic materials can be incorporated inside or above the NW design. In this regard, two novel designs of plasmonic NWSCs are reported and analyzed using 3D finite difference time domain method. The geometrical parameters of the reported designs are studied to improve their electrical and optical efficiencies. The ultimate and power conversion efficiencies (PCE) are used to quantify the conversion efficiency of the light into electricity. The first design relies on funnel shaped SiNWs with plasmonic core while the cylindrical NWs of the second design are decorated by Ag diamond shaped. The calculated ultimate efficiency and PCE of the plasmonic funnel design are equal to 44% and 18.9%, respectively with an enhancement of 43.3 % over its cylindrical NWs counterpart. This enhancement can be explained by the coupling between the three optical modes, supported by the upper cylinder, lower cone and plasmonic material. Moreover, the cylindrical SiNWs decorated by Ag diamond offer an ultimate efficiency and short-circuit current density of 25.7%, and 21.03 mA∕cm2, respectively with an improvement of 63% over the conventional cylindrical SiNWs

    THE BAKING QUALITY OF SOME WHEAT FLOUR MIXTURES

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    Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

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    © The Author(s) 2020. A covalent functionalization approach was utilized for the preparation of highly dispersed pentaethylene glycol-thermally treated graphene-water as the absorbing material inside a flat-plate solar collector. Four mass fractions of nanofluids were prepared (0.025, 0.05, 0.075, and 0.1 wt% pentaethylene glycol-thermally treated graphene-water). Graphene nanoparticles were characterized by energy dispersive X-ray analysis with a scanning electron microscope. Measurements of the thermophysical properties were subsequently carried out for the nanosuspensions. The raw investigation data were collected from an indoor flat-plate solar collector test setup. The experimental procedure included different sets of variables such as input temperatures of 303, 313, and 323 K; fluid mass flow rate of 0.00833, 0.01667, and 0.025 kg s−1; and heat flow density of 500, 750, and 1000 W m−2. The thermophysical tests of pentaethylene glycol-thermally treated graphene-water nanofluids showed a proportional increase against weight concentrations, while the specific heat power was reduced. The tests showed an increment in energy efficiency by increasing the fluid mass flow rate and heat input. By comparison, the thermal efficiency decreased with the increasing temperature of the fluid supply. Relative to the base fluid, the energy efficiency of pentaethylene glycol-thermally treated graphene/water-based flat-plate solar collector increased to 10.6%, 11%, and 13.1% at the three fluid mass flow rates. In conclusion, an exponential form was used to derive the thermal effectiveness of flat-plate solar collector based on the experimental data

    Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

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    © The Author(s) 2020. A covalent functionalization approach was utilized for the preparation of highly dispersed pentaethylene glycol-thermally treated graphene-water as the absorbing material inside a flat-plate solar collector. Four mass fractions of nanofluids were prepared (0.025, 0.05, 0.075, and 0.1 wt% pentaethylene glycol-thermally treated graphene-water). Graphene nanoparticles were characterized by energy dispersive X-ray analysis with a scanning electron microscope. Measurements of the thermophysical properties were subsequently carried out for the nanosuspensions. The raw investigation data were collected from an indoor flat-plate solar collector test setup. The experimental procedure included different sets of variables such as input temperatures of 303, 313, and 323 K; fluid mass flow rate of 0.00833, 0.01667, and 0.025 kg s−1; and heat flow density of 500, 750, and 1000 W m−2. The thermophysical tests of pentaethylene glycol-thermally treated graphene-water nanofluids showed a proportional increase against weight concentrations, while the specific heat power was reduced. The tests showed an increment in energy efficiency by increasing the fluid mass flow rate and heat input. By comparison, the thermal efficiency decreased with the increasing temperature of the fluid supply. Relative to the base fluid, the energy efficiency of pentaethylene glycol-thermally treated graphene/water-based flat-plate solar collector increased to 10.6%, 11%, and 13.1% at the three fluid mass flow rates. In conclusion, an exponential form was used to derive the thermal effectiveness of flat-plate solar collector based on the experimental data

    MHD heat transfer in W-shaped inclined cavity containing a porous medium saturated with Ag/Al2O3 hybrid nanofluid in the presence of uniform heat generation/absorption

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    © 2020 by the Authors. In this paper, a 2D numerical study of natural convection heat transfer in a W-shaped inclined enclosure with a variable aspect ratio was performed. The enclosure contained a porous medium saturated with Ag/Al2O3 hybrid nanofluid in the presence of uniform heat generation or absorption under the effect of a uniform magnetic field. The vertical walls of the enclosure were heated differentially; however, the top and bottom walls were kept insulated. The governing equations were solved with numerical simulation software COMSOL Multiphysics which is based on the finite element method. The results showed that the convection heat transfer was improved with the increase of the aspect ratio; the average Nusselt number reached a maximum for an aspect ratio (AR) = 0.7 and the effect of the inclination was practically negligible for an aspect ratio of AR = 0.7. The maximum heat transfer performance was obtained for an inclination of ω = 15 and the minimum is obtained for ω = 30. The addition of composite nanoparticles ameliorated the convection heat transfer performance. This effect was proportional to the increase of Rayleigh and Darcy numbers, the aspect ratio and the fraction of Ag in the volumetric fraction of nanoparticles

    Cress Seed (Lepidium sativum) Role in the healthy Processed Spread Cheese and Its Anti-Diabetic Activity

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    The present study dealt with utilization of cress seeds (Lepidium sativum) in the manufacture of processed spread cheese, instead of emulsifying salt. Cress seed have also health promoting properties especially lowering glucose ratios. Cress seeds powder were prepared and added with the ingredients during manufacture of processed spread cheese at levels of six ratios (0.05, 1.5, 2.5, 3.5, 4.5 and 5.5%) compared with control (3% commercial emulsifying salt). The chemical, physical, microbiology and organoleptic properties of resultant samples were evaluated. Data revealed that processed spread cheese sample fortified with 3.5% cress seeds was the best either when fresh or during storage (8±2ºC for 3 months) and they had acceptable properties. Microstructure of processed cheese spread samples were also conducted. From nutritional view, processed cheese spread samples fortified with 3.5% cress seeds were used for feeding Adult male albino rats to study their effect on plasma glucose level. Obtained data indicated that the glucose level in plasma was significantly decreased (
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