of these resources are finite including fossil fuels such as coal and oil. For the 21st century, coal, gas and oil are no longer recommended as we’re moving towards infinite renewable resources such as solar and wind power. The electricity and heat energy derived from these resources is used in our homes for every day uses such as cooking, lighting, air conditioning, refrigeration etc (see…
Occassionally, this model will be applied to non-point source emitters, such as exhaust from automobiles in an urban area. Air pollution is represented by an idealized plume coming from the top of a stack of some height and diameter. One of the primary calculations is the effective stack height. As the gases are heated in the plant (from the burning of coal or other materials), the hot plume will be thrust upward some distance above the top…
Theoretical analysis for HPHX's performance by using dimension analysis theory. Assumptions Steady operation conditions exist. The surface temperature of the condenser section is equal to the temperature of Refrigerant R-22. Properties The exit temperature of air, and thus the mean temperature, is not known. We evaluate the air properties at the assumed mean temperature of 42OC (will be checked later) and 1 atm as following: K= 0.02722 (W/m.K)…
Two computation cases were introduced, one with a polyurethane graft and another with a silicon rubber graft. The computations were done under a pulsatile flow. Both cases were computed under maximum peak pressure as mentioned in the method section. The flow volume rate is expressed by integrating on surface as followed: Q=∬_A^ ▒v.dA (5) By integrating flow volume rate in time…
3.1.3. TGA analysis Thermal gravimetric analyses (TGA) were recorded under N2 atmosphere over the temperature range of 25- 800 oC at a heating rate of 15 oC/min, to evaluate both the composition and the thermal stability of f-silica and AgNPs/f-silica. As shown in Fig. 1D the mass loss noticed between 25 oC and 180 oC represents the physically adsorbed water. Adsorbed water accounted 7.4%, 6.43% and 2.2% for f-silica, AgNPs/f-silica sample using [Ag+] = 0.005 M, and AgNPs/f-silica sample using…
Introduction Variables exist in experiments and can be linked together in the form of an equation. Some equations have constants that link the variables together in a sort of relationship. Gravity is considered a constant in many formulae including equations of kinematics and projectiles. In this experiment, the simple pendulum apparatus can be used investigate the relationship between the time period and the length of the pendulum, with a constant value including the value of gravity. This is…
Rosseland Radiation Model The Rosseland Model (Diffusion approximation model) is applicable when the medium is optically thick i.e. the optical thickness is much greater than 1 where a is the absorption coefficient of the medium, σ is the scattering coefficient of the medium and L is the average path length. The radiative heat flux is approximated as [3], (2.13) where qr is the radiative heat flux, Γ is the radiative diffusivity and G is the incident radiation. In contrast to the P-1 model…
high temperature heat addition and low temperature heat rejection at Ericsson cycle. The performance was evaluated in terms of thermal efficiency, exergy losses and specific power output. Energy and exergy analysis was carried out on Braysson cycle and Brayton cycle. The analytical formula was derived for energy efficiency, specific power output, exergy losses of each component, and the exergy efficiency. The influence of various parameters on the performance of the Braysson cycle and Brayton…
Table 2.1: Parameters of tested water turbines (by Shionoet.al, 2002) Solidity (σ) Chord length (C) (mm) Blade inclination angle(ɸ)(°) Height (h) (mm) 0.20 62.8 43.7 300 0.30 94.2 43.7 300 0.40 125.7 43.7 300 0.50 157.1 43.7 300 0.40 125.7 50.0 374 0.40 125.7 60.0 544 Next, the effect of solidity σ on the water turbine characteristics was measured. Figure 2.1 shows a comparative analysis of torque characteristics for different solidity ratios at velocity 1.0 m/s, performed by Shionoet.…
Flexible nature and high surface-to-volume ratio makes monolayer-MoS2 a novel paradigm for tunable gas sensing devices. However, for further improvement in the performance of these devices, a new design strategy is essential to modulate the sensitivity of inert MoS2 basal plane. Here, we demonstrate from first-principles calculations that the gas adsorption properties of monolayer-MoS2 can be modulated through MoS antisite doping and strain. The antisite doped MoS defect with highly localized…