Effect Of Wall Material Research Articles

Analisis SWOT Pemilihan Material Dinding Bata Merah dan Bata Ringan di Penajam Paser Utara

Infrastructure contruction has expanded in Penajam Paser Utara brought the effect of wall materials. Nowdays, Building construction with light brick preferably as an alternative than red brick it self. The aim of this research is to conduct SWOT Analysis between light brick and red brick in construction build in Penajam Paser Utara. According to question form that was spread in to local government has shown the results, The red brick sited in forth coordinate (quadrant) compare with light brick in second quadrant. This quadrant position provide using light bricks preferably were been selected than common red brick

Microencapsulation of docosahexaenoic acid (DHA) with four wall materials including pea protein-modified starch complex

Omega-3 fatty acids, specifically docosahexaenoic acid (DHA, 22 carbons and 6 double bonds) are fundamental compounds for a healthy diet. However, due to their unsaturated nature, omega fatty acid-rich oils are chemically unstable and susceptible to oxidative deterioration. The oxidation results in production of free radicals and unpleasant tastes, negatively impacting the shelf-life, sensory properties, and acceptability of food products. This study was conducted to examine the effect of wall materials on protection of DHA in canola oil against oxidation. A total of 4 wall materials including pea protein isolate (PPI), pea protein isolate - modified starch complex (PPI-MS), Tween 20, and SDS were used for microemulsion preparation with canola oil containing DHA. The freeze-dried powders were analyzed with respect to physicochemical characteristics, oxidative stability, and release properties. The results showed that the PPI-MS as a natural polymeric wall material exhibited similar or better encapsulation efficiency and acceptable level of peroxide value compared to the synthetic surfactants (Tween 20 and SDS). The utilization of protein-polysaccharide complexes enabled the incorporation of specific properties of each biopolymer to further improve emulsion stability for the production of capsules with improved oxidative stability.

Effect of wall materials on the spray drying efficiency, powder properties and stability of bioactive compounds in tamarillo juice microencapsulation

Hydro- and lipo-soluble bioactive compounds, such as anthocyanins and carotenoids, in tamarillo juice were microencapsulated using different wall materials, such as maltodextrin (MD), n-octenyl succinic anhydride modified starch, from waxy maize for high load encapsulation (OSA 1), low viscosity gum Arabic alternative (OSA 2), resistant maltodextrin (RMD) and gum Arabic (GA). The wall materials were characterized according to their physicochemical and functional properties, molecular weight distribution and encapsulation efficiency using X-ray diffractometry. The tamarillo powders obtained after spray drying were evaluated for their physicochemical and thermal properties, phenolic content, flavonoid content, antioxidant capacity and storage stability. Although there were significant differences in terms of the encapsulation efficiencies of the wall materials, yield, physical properties and storage stability of the spray dried powders, all of the wall materials successfully encapsulated the hydro- and lipo-soluble bioactive compounds. The viscosity, amorphous region and molecular weight of the wall material had positive influences on the encapsulation efficiency, powder properties and storage stability of the encapsulated tamarillo juice. The storage stability of the powders depended on their water activity, hygroscopicity and glass transition temperature (Tg). The tamarillo powders showed greater anthocyanin and carotenoid degradation in the presence of light at 25°C compared to the powders stored in the dark at 4°C. GA and OSA 1 resulted in the highest encapsulation efficiency for both the hydro- and lipo-soluble bioactive compounds, while OSA 1 and MSB showed the greatest storage stability. Reductions in the antioxidant activity, phenolic content and flavonoid content during storage will contribute to the degradation of anthocyanins and carotenoids.

Effect of wall material on water nanovortices formation in 2D long open type nanocavity. Molecular Dynamics study

In our earlier papers [18,19] we showed the dependence of water nanovortex structures in long open type quartz nanocavities on their sizes. Here we study the effect of wall material limiting the water flow on the nanovortex structure.The artificial wall material was constructed by omitting electric charges in ClayFF [8] molecular model of quartz. It caused weaker interactions between molecules of the wall and water during the NEMD simulation of the flow, as compared to the case when the water flow was limited by the quartz [8] wall.Hydrodynamic bulk parameters obtained by averaging the NEMD simulation data of 19ns water flow in two nanochannels of 22nm height with perpendicular nanocavities of 25.2nm length and 7nm width of different wall material were compared and analysed.The findings show that the wall material has a significant influence on the water flow structure and main nanovortex position. In the nanocavity whose wall material interacts stronger with water molecules the main vortex centre shifts to the front wall of the nanocavity and is situated closer to main nanochannel axis than in nanocavity where forces of intermolecular interactions between the wall material and water molecules are weaker. Our findings and conclusions obtained from this paper show nanovortices as potential promising tools for applications in nanobiological and nanofluidic devices.

Microencapsulation of walnut oil by spray drying: Effects of wall material and drying conditions on physicochemical properties of microcapsules

Abstract In this study, the effects of wall material formula and spray drying conditions on physicochemical properties of walnut oil microcapsules were investigated. Three different wall materials including skim milk powder (SMP), SMP + Tween 80, and SMP + maltodextrin were used for emulsion preparation. The prepared emulsions were analyzed for droplet size and stability. The emulsions were then dried in a pilot-scale spray dryer equipped with a two-fluid nozzle at different inlet drying air temperatures and feed atomization pressures in order to determine the optimal drying conditions for maximizing the microencapsulation efficiency. The microencapsulation efficiency, particle size distribution, sphericity, moisture content, bulk density, and morphology of produced microcapsules were also measured experimentally. In addition, the microcapsules with the highest microencapsulation efficiency obtained from each wall material were subjected to surface coverage of oil test using electron spectroscopy for chemical analysis (ESCA) after 60 days of storage at room temperature. The emulsion prepared using SMP and Tween 80 combination as wall material resulted in the highest microencapsulation efficiency (91.01%) at drying air temperature of 180 °C and feed atomization pressure of 3 bar. The lowest surface coverage of oil was also observed for microcapsules covered by SMP and Tween 80 combination. Scanning electron microscopy (SEM) observations showed almost no cracks or fissures on the surface of microcapsules produced using SMP and Tween 80 combination at the optimal drying condition. Industrial relevance Walnut oil contains highly valuable constituents such as essential fatty acids, tocopherols, and phytosterols. However, a direct application of this functional oil in processed foods is problematic due to its low solubility and susceptibility to oxidation. These issues could be greatly overcome by using microencapsulation technology. Nowadays, this technology has received an increasing attention in food and pharmaceutical industries due to its unique features in protecting the functionality of ingredients. Spray drying technology is one of the most frequently used techniques for this aim. However, comprehensive studies need to be carried out in order to determine suitable operational conditions of spray drying system for improving physicochemical properties of finished powder.

Effect of wall heat transfer characteristic on the micro solid thruster based on the AP/HTPB aerospace propellant

The combustion processes of Ammonium perchlorate/Hydroxyl-terminated polybutadiene (AP/HTPB) aerospace propellant are analytically studied to determine the effect of wall materials and thickness on the heat transfer characteristics within a solid micro thruster. In this study, the flow and combustion characteristic of the propellant are described in terms of a combustion rate equation associated with a chemical reaction kinetics model. The profiles describing changes in the combustion surface by the user-defined function (UDF) are used to obtain the distribution of temperature and content of propellant using a numerical method. The combustion time and thrust are simulated to validate the results by comparing them with the results from the literature. Moreover, we demonstrate that a smaller thermal conductivity and a larger heat capacity of the wall material can lead to improvement in the thruster performance. Finally, analyzing the significant effects of wall thickness the heat transfer characteristics within the thruster allowed us to determine an optimal wall thickness value.

Effect of Wall Material on the Property of Gac Oil Spray-dried Power

Gac fruit (Momordica cochinchinensis, Spreng) aril contains extraordinarily high levels of β-carotene, lycopene and unsaturated fatty acids, especially oleic and linoleic acids. These bioactive compounds have been proven to be beneficial to human health and are linked with a reduced risk of cardiovascular disease and cancers. There were previous researches which were carried out to encapsulate Gac oil using maltodextrin, whey protein and gum arabic. However, no reports have been found to study cyclodextrin and sodium caseinate as a carrier or encapsulating agent for producing Gac oil powder. The aim of this study using spray drying method was therefore to investigate the impacts of wall concentration on Gac oil microencapsulation. The data showed that 25% of maltodextrin (or cyclodextrin); ratio of maltodextrin (or cyclodextrin) and sodium caseinate of 0.6:1 resulted in high microencapsulation productivity. The figure of MEY, MEE and DY accounted for 92.4%, 66% and 70.3% respectively and higher than that of other samples. Gac powder is saffron color of turmeric, specific odor and completely dissolved in water. The moisture content reduced from 3.67% to 3.03% when increasing the rate of maltodextrin/ sodium casenate and cyclodextrin/sodium casenate, and more than 86% dissolved in water. Sodium casenatecyclodextrin matrix as the wall material was effectively used for spray-drying encapsulation of Gac oil.

Effect of wall materials and core oil on the formation and properties of styralyl acetate microcapsules prepared by complex coacervation

Styralyl acetate (SA) was encapsulated in gelatin and gum Arabic using complex coacervation. The response surface methodology was carried out to explore effects of wall concentration and the amount of SA on the yield, encapsulation efficiency, and oil loading capacity and to optimize the process conditions. The results of optimization showed that the wall concentration of 1.35 % (w/v) and the SA of 2.23 g were used, the highest yield of 72.8 %, encapsulation efficiency of 80.6 % and oil loading capacity of 66.2 % were obtained. The morphologies were observed by an optical microscope and scanning electron microscopy (SEM), respectively. Microcapsules exhibited excellent thermal stability than SA by thermogravimetric analysis (TGA). Moreover, Fourier transform infrared and X-ray diffraction examined structure changes of wall materials and core oil.

English

The effects of wall materials and encapsulation by lyophilization on the viability of Weissella confusa were evaluated. Aloe vera gel, sodium casein at 5 and 15% p/v, sodium alginate at 2% p/v, buffer phosphate, and a mixture (Aloe vera gel, sodium casein, and sodium alginate) as wall materials, were used. Bacteria without encapsulation ( W. confusa ) as control were used. Encapsulated bacteria were freeze dried for 48 h, in order to determine their viability in the freezing and sublimation-drying stages. Results indicate that bacteria without encapsulation, showed greater loss of viability in the sublimation-drying stage. All the wall materials evaluated, may be used for encapsulation of bacteria, because, at the end of the freeze-drying process, the encapsulated bacteria showed higher viability percentages than non-encapsulated bacteria, with significant statistical difference (p<0.05). The protective effect of wall materials was higher in the sublimation-drying stage, compared to freezing stage. Keywords: Aloe, Weissella , probiotic, encapsulation. African Journal of Biotechbiology , Vol 13(26) 2661-2667

Detailed transient numerical simulation of H2/air hetero-/homogeneous combustion in platinum-coated channels with conjugate heat transfer

Transient two-dimensional simulations of fuel-lean H2/air combustion were performed in a 2-mm-height planar channel coated with platinum, using detailed hetero-/homogeneous chemistry and transport as well as heat conduction in the solid wall. The developed model resolved, for the first time, all relevant spatiotemporal scales in a practical channel-flow reactor configuration. A parametric study was carried out to investigate the effects of wall material, inlet velocity, and inlet temperature on the fundamental catalytic and gas-phase combustion processes. Computational singular perturbation (CSP) analysis identified the key catalytic reactions affecting light-off and homogeneous ignition. Homogeneous ignition crucially depended on the OH desorbing fluxes from the catalyst, while flame propagation and stabilization involved time scales of a few milliseconds. During the short duration of the light-off event, the ensuing Stefan velocity appreciably altered the flow field. Predictions of time accurate numerical simulations were further compared against those of a code relying on the quasisteady state assumption, and the specific conditions under which the latter was invalidated were identified. Finally, CSP analysis unraveled the reasons for the high computational cost of the fully transient 2-D simulations. The surface reaction mechanism exhibited a high stiffness with fastest time scales of the order of 10-12s, pertaining to the hydrogen adsorption and to the H(s)+O(s)=OH(s)+Pt(s) reactions. These time scales were in turn six orders of magnitude shorter than the ones associated with gas-phase chemistry or with a simplified single-step catalytic reaction.

SU-E-T-82: Change of Ionization Chamber Correction Factors (Ppol , Pion , KWall ) with Chamber Walls of Different Materials in Continuous and Pulsed Beams

Purpose: To study the effect of wall material on correction factors for polarity effect Ppol , collection efficiency Pion and scatter and attenuation in the chamber wall/central electrode Kwall , in continuous and pulsed beams. Methods: An Exadin A12 ionization chamber was modified to have geometrically identical chamber walls built from aluminum and copper. Measurements were performed using the different walls in both 60Co, and Varian‐Clinac 21EX 6 MV beams. Ppol was measured using AAPM TG51 protocol. Pion was obtained form measurement data, where the collected charge was measured at 10 voltage settings and used to form Jaffe‐plots. Measurements were compared against Monte Carlo simulated data (egs++/egs_chamber). Kwall values were also calculated using CAVRZnrc. Results: For all beams and all wall materials, Ppol was found to be less than the 0.3 % limit recommended in TG‐51. Saturation charges (extrapolated from the Jaffe‐plots) were observed to increase with wall materials of increasing atomic number Z. The breakdown of the Boag‐predicted linearity of Jaffe‐plots in the near‐saturation region was observed for all beam types and wall materials. The ratio of the saturation charges (relative to the C552 wall) were predicted by cavity theory, and agreed with simulations to within 9.8 % for 60Co and 5.2 % for 6 MV. Pion measured by the two‐voltage technique and from Jaffe‐plots were all found to be less than the 1.05 accepted upper limit recommended by TG‐51. Kwall showed that attenuation and scatter for the Cu wall influences the measured signal by 1.9 % for 60Co. Conclusion: Ppol and Pion were measured for an Exradin A12 chamber with C552, Al, and Cu wall materials. The basic behavior of Jaffe‐plots is independent of wall material. As expected, Kwall increases drastically for high Z walls with decreasing beam energies.

Monte Carlo-based energy response studies of diode dosimeters in radiotherapy photon beams

This study presents Monte Carlo-calculated absolute and normalized (relative to a (60)Co beam) sensitivity values of silicon diode dosimeters for a variety of commercially available silicon diode dosimeters for radiotherapy photon beams in the energy range of (60)Co-24 MV. These values were obtained at 5 cm depth along the central axis of a water-equivalent phantom of 10 cm × 10 cm field size. The Monte Carlo calculations were based on the EGSnrc code system. The diode dosimeters considered in the calculations have different buildup materials such as aluminum, brass, copper, and stainless steel + epoxy. The calculated normalized sensitivity values of the diode dosimeters were then compared to previously published measured values for photon beams at (60)Co-20 MV. The comparison showed reasonable agreement for some diode dosimeters and deviations of 5-17 % (17 % for the 3.4 mm brass buildup case for a 10 MV beam) for some diode dosimeters. Larger deviations of the measurements reflect that these models of the diode dosimeter were too simple. The effect of wall materials on the absorbed dose to the diode was studied and the results are presented. Spencer-Attix and Bragg-Gray stopping power ratios (SPRs) of water-to-diode were calculated at 5 cm depth in water. The Bragg-Gray SPRs of water-to-diode compare well with Spencer-Attix SPRs for ∆ = 100 keV and above at all beam qualities.

Effect of wall surface reaction on a methane-air premixed flame in narrow channels with different wall materials

In order to elucidate effect of wall material on chemical quenching behavior, a methane-air premixed flame formed in 5-mm-wide channel is investigated. In the present study, platinum, quartz, alumina and chromium are chosen as the wall materials. Platinum, chromium and alumina thin films ∼100nm in thickness are deposited on quartz substrates using sputtering, vacuum arc plasma gun or atomic layer deposition techniques to establish equivalent thermal boundary condition with different wall chemical reactions. OH-PLIF/micro-OH-PLIF and numerical simulation with detailed reaction mechanisms are employed to examine interaction between the gas-phase and the wall surface reactions. It is clearly shown through the PLIF measurements that OH∗ mole fraction in the vicinity of the wall is the highest for alumina, while it is decreased in order of quartz, chromium, and platinum. On the platinum surface, the gas-phase combustion is suppressed due to fast consumption of the reactants by the catalytic reaction. On the other hand, on the other surfaces, radical quenching cause the reduction of OH∗ near the wall. By using a radical quenching model, the initial sticking coefficient associated with radical adsorption is evaluated. It is found that radical quenching does exist on the quartz wall, while the alumina surface works as an inert surface.

Sensitization of the analytical methods for photoneutron calculations to the wall concrete composition in radiation therapy

The effect of wall material on photoneutron production in radiation therapy rooms was studied using Monte Carlo (MC) simulations. An analytical formula was proposed to take into account the concrete composition in photoneutron dose calculations. Using the MCNPX MC code, the 18 MV photon beam of the Varian Clinac 2100 and a typical treatment room with concrete compositions according to report No. 144 of National Council of Radiation Protection (NCRP) were simulated. Number of room produced photoneutrons per Gray of X-ray at the isocenter was determined for different types of concrete and named as “Q W ”. This new factor was inserted in the used formula for photoneutron fluence calculations at the inner entrance of maze. The photoneutron fluence was calculated using new proposed formula at the inner entrance of maze for all studied concretes. The difference between conventional and proposed equations varied from 11% to 46% for studied concretes. It was found that room produced photoneutrons could be significant for high density concretes. Additionally, applying the new proposed formula can consider the effect of wall material composition on the photoneutron production in high energy radiation therapy rooms. Further studies to confirm the accuracy of newly developed method is recommended. ► A radiation therapy room with a linac was simulated in the current study. ► Photoneutron production from different commercial concrete was studied. ► The photoneutron production varied from 11% to 46% dependent on concrete density and elemental composition. ► Photoneutron production was higher for high density concretes.

Axial heat conduction and heat supply effects on methanol-steam reforming performance in micro-scale reformers

The methanol-steam reforming (MSR) performance in micro-scale tubular reformers made by various materials is numerically studied. The physical domain considered includes an inlet section for methanol-steam mixture supply, a reformer section packed with CuO/ZnO/Al2O3 catalyst particles and an outlet section for reformed gas collection. The heat transfer effect with three different heat supply mechanisms on the MSR performance is addressed. For heat supplies from the applied heat fluxes at the reformer outer wall surface and from internal heat generation in the reformer wall, it is found that the axial conduction plays an important role in both heat transfer characteristics and MSR performance. It is suggested that the reformer have a small axial conduction parameter for high MSR performance which can be achieved by designing the reformer with low wall thermal conductivity, thin wall thickness and a small reactants feed rate. It is also found that an excess heat supply can be obtained when the axial conduction parameter is small. This excess heat supply enhances the MSR performance compared with the infinitely-thin walled reformer. For the reformer with a constant wall outer surface temperature, the wall material effect on the MSR performance is insignificant due to uniformly distributed reformer wall temperature.

Effect of wall material and shape on MeV ion focusing ability of tapered capillary optics

The dependence of the MeV ion focusing ability of tapered capillary optics on the capillary wall material was investigated using tapered glass capillaries made of two different glass materials: borosilicate glass and lead glass. The energy spectrum measurement of capillary-focused proton beams showed that the beam focusing ratio for the lead glass capillary was slightly higher than that for the borosilicate glass capillary, but the enhancement was much lower than expected from the target atomic number dependence of the Rutherford scattering cross section. Three-dimensional Monte Carlo simulations were performed to examine the effect of the capillary wall shape as well as that of the wall material. When a constant taper angle capillary was used, the beam focusing ratio was found to be enhanced by a factor of 2 compared to when the conventional tapered capillary having a convex inner wall was used. These results indicated that the probability of the scattered ion escaping from the capillary wall plays a predominant role in the MeV ion transmission in the tapered capillary optics.

Effect Analysis of Different Wall Materials on Construction Project Cost

Economy was compared for same building with price and cost of wall material, the other building materials (such as steel bars and pipe pile) and the cost for building energy efficiency. The results shown, Cost effect of wall material and cost difference of other building materials (such as steel bars and pipe pile) because of wall material weight difference are few for building cost. Building energy efficiency cost effect of wall material is significant for building cost. For high-rise frame structure, autoclaved aerated concrete block is inexpensive wall material.

A Surface Analysis-Based Investigation of the Effect of Wall Materials on Flame Quenching

An investigation of a premixed methane-air flame was conducted with a slit burner between two parallel walls to examine the effects of wall material and temperature on flame quenching. Three different materials (i.e., zirconia ceramics, stainless steel 304, and Si) were tested at wall temperatures of 100–700°C. The quenching distances for the three wall materials at the same temperature decrease in the order stainless steel 304 > Si > zirconia ceramics. For all materials, the quenching distance shortens with increasing wall temperature. To clarify the differences among the materials, the surface structure and composition of the raw and used walls were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The results show that the percentages of chemisorbed oxygen on the surfaces decrease in the order zirconia ceramics > Si > stainless steel 304—a behavior that can be correlated with the order of quenching distances of the three wall materials, which moves from small to large. In short, the higher the percentage of chemisorbed oxygen, the shorter the quenching distances.

Numerical Simulation for the Effect of Wall Material on Near Wall Conductivity in Hall Thrusters

The wall material plays an important role for the electron current due to near wall conductivity in Hall Thrusters. A Monte Carlo method combined with a one dimensional steady sheath model is presented and is applied to simulate the electron conductive current due to near wall conductivity for the different channel wall materials of Hall thruster. The simulation results show that the higher the secondary electron emission (SEE) coefficient of the channel wall material is, the greater the electron conductive current is. Based on the simulation, a physical explanation is given from the viewpoint of near wall conductivity. For the channel wall material with low SEE coefficient, the secondary electrons taking part in the near wall conductivity becomes less. In addition, the absolute potential drop in the sheath near the wall increases, which means that the sheath can stop more electrons from colliding with the channel wall. And consequently the electron conductive current due to near wall conductivity is much less. The situation is vice verse for the channel wall material with high SEE coefficient. The simulation results are qualitatively in accordance with the experiments. The results can help to choose and design the wall material of the Hall Thrusters with a high performance.

Deformation and fragmentation behaviour of exploded metal cylinders and the effects of wall materials, configuration, explosive energy and initiated locations

Tubular metal specimens are explosively expanded to fragmentation, and the effects of wall materials, thicknesses, notches in walls, explosive driver diameters and the initiated locations are investigated on the deformation and fracture behavior of the cylinders experimentally and numerically. In the standard tests, the driver is a column of low density powder of high explosive PETN, inserted coaxially into the bore of a smooth-walled cylinder and initiated by exploding a bundle of fine copper wires at the column axis using a discharge current from a high-voltage capacitor bank. Notched cylinders with single axial slit, various grooves in the walls, and smooth cylinders with varied wall thicknesses were tested. Low-carbon steels and an aluminum alloy A5052 were provided in addition to the standard smooth-walled 304 stainless steel cylinder, and they were fully or partially charged with varying explosive column diameters. The initiated locations in the explosive column are changed for comparison, placing the bundle of fine copper wires eccentrically from the central axis or replacing the fine wire bundle into a bold wire line except the middle portion at the central axis for central point initiation. Additionally an explosive-filled cylindrical vessel with welded endplate at the one end is initiated at the other end explosive surface exploding wire-rows and expanded by axially propagating explosive detonation to fracture for comparison with the uniform expansion. Deformation and crack initiation of expanding cylinders are observed with high speed camera, and most of the fragments have been recovered successfully. Recovered fragments have been measured and investigated using a fragmentation model. The effects of test parameters on the deformation and fracture behavior of metallic cylinders are discussed with use of numerical simulations, indicating applicability of the fragmentation model and suggesting future necessary studies.