A numerical study has been carried out on a new design of ejector diffuser (infrared suppression device). New design conceptualizes exploiting the shape of the slot openings. A circular arc is provided to guide the entrained fluid at the slot openings. Performance of guided-slot ejector diffuser (GED) has been compared with conventional (non-guided-slot) ejector diffuser (NGED) in terms of local and cumulative mass entrainment ratios, temperature distribution and static pressure recovery. Three slot-area variations are also studied, namely (i) increasing slot-area ranging 1 ≤ A0 ≤ 2. 02, ( 0A is area of 1st slot) (ii) constant slot-area A0 = 1 and (iii) decreasing slot-area ranging 0. 49 ≤ A0 ≤ 1. Simulations have been carried out at fixed Reynolds number Re = 1. 3  105. It is observed that GED has 3. 5% higher cumulative mass entrainment ratio than NGED. GED forms cold annulus region below ejector diffuser wall from 1st slot onwards which results in wall temperatures being close to ambient temperature (300 K). Higher mass entrainment rate and lower wall temperatures make GED a better infrared suppression device but static pressure recovery is better in NGED (Cp = 0. 79) compared to GED (Cp = 0. 43). Slot-area study reveals that the performance of increasing slot-area for GED and NGED is superior then constant and decreasing slot-area configurations. The cumulative mass entrainment is 20% higher while static pressure recovery is 45% more for the increasing slot-area GED when compared to the decreasing slot-area GED.

Brackets and various arch-wires are used in fixed orthodontic appliances to apply forces to the teeth. The amino-acid glutamate is one neurotransmitter that has been discussed in the context of pain processing and has been linked to a variety of pain syndromes. This study aims to evaluate pain between Double slot orthodontic brackets versus single slot with a visual scale and a saliva biomarker (glutamate testing) and CRP. This randomized clinical trial (double-blind) was conducted in Dentistry/Howler Medical University. 41 patients (26 females and 16 males) aged of 18-23 years old with class II malocclusion were selected from patients seeking orthodontic treatment after proper diagnosing using digital cephalometry, OPG. The patients who were chosen randomly received either a single arch-wire (0.014 NiTi) or a double arch-wire (one 0,014 NiTi and the second 0.012 NiTi). Two saliva samples were prepared and analysed to measure glutamate and CRP and evaluate pain using the visual analogue scale. The mean visual scale was 4.38 in the two-wire group compared to the single-wire cases, which was 2.80 showing a significant difference (P ≤ 0.001). There was a significant statistical difference between glutamate after and before treatment for single and double-slot bracket cases. There was a significant difference in mean pain scores between two group with less pain in single wire with a Visual analogue scale, but there is an insignificant difference with saliva glutamate measurement. However, the levels of glutamate before and after applying force were significant in both groups.

It has been proved that suitable slot structure of compressor slotted blade can generate high-momentum jet flow through pressure difference between the pressure and suction surface, the slot jet flow can reenergize the local low-momentum fluid to effectively eliminate the flow separation. In order to investigate and evaluate the impact of full-span slot and blade-end slot on the performance of the post-loaded blade, which has serious flow separation on the suction surface both near blade midspan and endwall, a diffusion stator cascade with large camber angle is selected as the research object. Firstly, the blade-end slotted scheme and the full-span slotted scheme are set up. Then the performance of datum cascade and two slotted cascades is computed in the wide incidence angle range of-8º to 6º at the Mach number of 0. 7, the corresponding blade-chord-based Reynolds number 〖Re〗_C is 7. 7×10^5. Finally, the performance of the three cascades is analyzed and compared. The results show that, in the computational incidence angle range, both of the two slotted schemes can reduce the total pressure loss for datum cascade and enhance its pressure diffusing capability. However, compared with the blade-end slot, the full-span slot has a better comprehensive control effect on the corner separation and the boundary layer separation near blade midspan, hence, compared with those of blade-end slotted cascade, the total pressure loss coefficients and the static pressure coefficients of full-span slotted cascade are respectively further decreased and increased. Under the blowing effect of full-span slot jet, the total pressure loss coefficients of datum cascade are significantly decreased, ranging as high as 21. 2%, 23. 1%, 24. 5% and 23. 4% under the incidence angles of 0°, 2°, 4° and 6°, respectively. The full-span slotted scheme has a better adaptability to wide incidence angle range, it can effectively broaden the available incidence angle range for datum cascade.

Numerical study of hyperthermia was performed using a microwave slot antenna in the treatment of liver cancer. The modeling of the problem in Comsol software is done symmetrically and two-dimensionally and the electromagnetic equation is coupled with the biothermal transfer equation. Temperature distribution, cancer tissue destruction, microwave absorption in liver tissue and specific absorption rate (SAR) are presented as results. The results showed that the two-hole antenna has a wider distribution of the amount of microwave absorbed than the single-slot antenna. The SAR distribution along the longitudinal axis of the antennas gradually increases and reaches its maximum point where the slot is located, and then the SAR distribution decreases rapidly and reaches its minimum at the end of the antenna. According to the results, changes in temperature in liver tissue also depend on the type of antenna and penetration depth, and temperature distribution and SAR distribution have a similar trend. Also, single-slot antenna is suitable for elliptical tumors and double-slot antenna is suitable for spherical tumors.

In this paper, a novel low-profile switchable narrow and wide band circular ring sector slot antenna is presented for wireless applications. Adjustable operating frequencies especially with the ability of switching between narrow and wide band modes could provide considerable immunity from jamming and noises. The combination of two wideband and six narrowband modes are provided using PIN diode switches inserted on the relatively wide slot. The slot is etched in the ground plane with the size of 33×36 mm2. The results show the operating frequency bands of 3. 47-5. 48 GHz for the first wideband operation and 5. 2-7. 37 GHz for the second wideband operation with S11<-10 dB. In narrowband modes, the operating frequencies can be adjusted from 2. 58-3 and 4. 88-5. 5 GHz for the first (f1) and second (f2) resonances, respectively. The proposed antenna is suitable for applications such as WLAN IEEE 802. 11a (5. 1 to 5. 8 GHz), WiMAX (2. 5– 2. 8 GHz), the ultra wideband (UWB) sub-band groups (3. 5– 5 GHz and 5– 6. 5 GHz) and also C-band radars.

The frequency bandwidth of microstrip patch antennas can be increased using both of U-slot and proximity feeding. Although some design rules have been already explained for the probe-fed U-slot antenna the proximity coupling causes to consider a lot of parameters for design procedure; consequently, to deal with all of them seems confusing. In this paper after investigating the effect of various parameters on the multiple resonant frequencies of the antenna and recognizing the most effective factors, some guidelines to design a proximity coupled U-slot microstrip antenna are proposed. In addition, an antenna element with 16% impedance bandwidth is designed at center frequency of 16.7GHz, and its broadband impedance and radiation characteristics are vastly considered. Also, 1×2 and 2×2 arrays of the antenna element are designed to use as subarrays for designing large arrays. The measurement results of return loss and radiation pattern, show good agreement with simulation results.