China
Africa
Explore chapters and articles related to this topic
Mensuration
Published in W. Bolton, Mathematics for Engineering, 2012
The frustum of pyramid is the portion cut off between the base and a plane parallel to it; it is sometimes called a truncated pyramid. Figure 2.22 illustrates this for a square-based pyramid with the frustum cutting off an upper pyramid from the original pyramid of vertical height H to leave a height h. Let A be the base area of the original pyramid and a the area of the cut surface. The areas are equal to the squares of the lengths of the corresponding sides, hence: aA=(ab)2(AB)2
Compact Corner Truncated Fractal Slot Antenna for Cognitive Radio Sensor Network
Published in IETE Journal of Research, 2023
The combinational effects of fractal slots, corner truncation and EBG pattern generate field correlation in EM distribution. The varying distribution on the top surface indicates the relative change of impedance over the path of current from feed strip to broad edges. The mutual coupling is conceptual orientation of the electrical equivalences of inductive-capacitive (LC) network arrays of slot structures. Eventually, truncated corner reflects the overall geometry by inserting orthogonality in the E-M field generation. Based on the effects of self, cross and mutual coupling on radiating structure, the antenna offers net radiation resistance to maximize the radiation efficiency within the permissible trade-off. This radiation efficiency justifies the tolerance against noise immunity and offers high SNR values of scanning network, as shown in Figure 17. The proposed antenna offers approximately 79.9% average radiation efficiency with a peak of 92% for higher frequency range (7–12 GHz). The recorded efficiency of the antenna is found suitable to sustain permissible limits of SNR under the transmission control protocols for both narrow and wideband scanning.
In situ preparation, structure, photophysical properties of a novel zinc complex
Published in Inorganic and Nano-Metal Chemistry, 2022
Yang-Qing Chen, Hai-Qi Peng, Qiong Ji, Xuan-Xuan Wang, Lijun Wei, Qiu-Yue Zhong, Wen-Tong Chen
To better understand the essence of the photoluminescence of complex 1, theoretical computations have been carried out. In order to avoid the complexity, complex 1 was truncated into a ZnI3(N-benzyl-4,4′-bipy) moiety with the methanol molecules and water being omitted. The ground state geometry was adapted from the single crystal X-ray data of the truncated moiety. Based on this ground state geometry, a TDDFT (time-dependent DFT) calculation was carried out. The characteristics of the highest occupied molecular orbital (HOMO with the energy being of −0.175337 Hartrees) and the lowest unoccupied molecular orbital (LUMO with the energy being of −0.160652 Hartrees) of complex 1 is depicted in Figure 7. The energy difference is 0.014685 Hartrees between the HOMO and LUMO. The electron distribution of the singlet state of the HOMO mainly locates at the pyridyl ring that is coordinated to the zinc ion, while that of the LUMO mainly resides at the benzyl group. As a result, the charge is transferred from one of the pyridyl rings to the benzyl group. This suggests that the photoluminescence emission spectrum of complex 1 can be attributed to an intraligand charge transfer (ILCT) that is similar to the cases documented in the references.[42,43]
The Effects of Turbulence on Jet Stability and the Flame Transfer Function in a Lean-burn Combustor
Published in Combustion Science and Technology, 2020
N. C. W. Treleaven, A. Garmory, G. J. Page
In order to obtain the FTF of this injector the computational domain was truncated to only include the rig geometry downstream of the three flow passage exits of the fuel injector. These three injector exits then become the inlets to the truncated simulation geometry. This was previously done in Treleaven, Garmory, and Page (2019) and this study uses the same computational mesh. This truncated domain was run assuming incompressible flow with the three PODFS models obtained from the auxiliary URANS simulation providing the fluctuating velocity field to the three inlets that represent the outlets of the fuel injector. The simulation was first run for 4000 iterations with only the mean components of the velocity field imposed at the inlets with a time step of to obtain a pseudo-steady solution. Dodecane fuel was injected as Lagrangian parcels from the first time step at 100 equidistant points around the circumference of the main flame atomizer and at 50 points around the circumference of the pilot atomizer. The fuel parcel diameters were chosen at random according to a Rosin-Rammler distribution with a mean SMD (Sauter mean diameter) of . The evaporation of the fuel droplets is assumed to follow the work of Lefebvre and Chin (1983). The flow was ignited after 100 iterations by heating a small portion of the flow to a high enough temperature to initialize the reaction.