In this paper, a new composite artificial magnetic conductor (AMC) surface with magneto-dielectric substrate is presented for wide band radar cross section (RCS) reduction. It is shown that magneto-dielectric substrate can increase the in-phase reflection bandwidth of AMC structure. In this structure, the composite surface consists of two AMC types that operate at two different resonance frequencies. The phase difference between these two AMC types is tuned to be close to ±180 over a wide bandwidth so that the reflections from them cancel each other. The results show with this technique, RCS reduction more than 13 dB was achieved with a 93% bandwidth.

In this paper, a wideband printed antenna over an artificial magnetic conductor (AMC) surface is introduced which can be utilized for wireless applications such as WLAN, WiMAX, and multiple-input multiple-output (MIMO) systems. In the proposed structure, a planar AMC surface as the antenna ground plane is used to direct the radiation pattern of the antenna, and enhancing the impedance bandwidth. The proposed antenna design is composed of a pair of printed microstrip elements fed by an E-shape feed line for coupling the elements. The bandwidth of the designed antenna includes from 4. 94 GHz to 6. 9 GHz with a return loss of less than-10dBforlinear polarization in C-band. The rhombic-shape AMC unit cell indicates the bandwidth of 5. 24-7. 15 GHz for the ± 90˚ reflection phase. By adding the AMC surface into the printed antenna, a wideband structure with acceptable miniaturization and gain enhancement to 7. 25 dBi is achieved. The simulated results of the antenna’ s impedance properties are performed by using full-wave simulators of HFSS and CST. Also, two-element array of the proposed design are investigated for different polarizations. Based on the obtained results, the operating bandwidth includes the frequency range from5. 18GHz to 6. 81 GHz and the isolation between the array elements is less than-22 dB. For this purpose, the antenna arrays can be applied for MIMO systems.

In this paper, a new scheme for completely reliable transmission of the information (with an error probability tends to zero) in a wireless communication link will be proposed in which to compensate the effects of fading and multipath, adaptive modulation and coding is used. Obviously, by the practical forward error correction it is impossible to achieve error free communication. Removing the residual error is by an auto-forwarding system. Of course, if error correction coding capability is weak, number of retransmissions will be increased to the much needed and it severely undermines the system throughput. On the other hands, strong error correction capability needs high block length codes and high transmission power which are limited in practice. In this paper, a method for optimum combination of error correction and auto forwarding is provided. In this paper, link adaptation is based on imperfect channel state information. Numerical results demonstrate efficiency of designed method.

A compact microstrip antenna by applying a parasitic artificial magnetic conductor (AMC), is proposed for facilitating 4G and 5G wireless communications. The antenna design includes microstrip dipoles fed by a T-shaped feedline. Notably, the antenna achieves a measured bandwidth of 5.32-6.73 GHz (with S11≤ -10 dB). To enhance performance, a proposed parasitic AMC reflector is integrated into the antenna structure. Incorporating an 8×8 AMC array, the antenna extends its -10 dB measured bandwidth from 4.55 to 6.83 GHz, catering to both 4G and 5G communication standards. Comparative analysis with an antenna lacking AMC reveals a reduced size of 34%, alongside a notable gain of 8 dBi and uni-directional radiation patterns. The efficiency and gain of all elements are approximately 90% and 8 dBi, respectively. Moreover, the introduction of an AMC unit cell, well-founded on a parasitic patch, resonates at 6.12 GHz with a bandwidth extending from 5.25 to 7.15 GHz. Furthermore, the offered equivalent transmission line model of the antenna with the AMC is demonstrated, yielding desirable results. This model accurately predicts the input impedance of the antenna with AMC across a broad frequency band ranging from 4.61 to 6.72 GHz. This comprehensive study demonstrates the effectiveness and versatility of the offered model in characterizing the operating band's behavior of the antenna across a wide frequency band to facilitate its design and optimization for various applications.

In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features.To more readily understand the operation mechanism of proposed feeding structure, an efficient circuit model has been also presented.It is known that proximity and aperture coupled feeding structures are sensitive to the transverse feed point location. In contrast, the proposed feeding architecture is very easy to fabricate and it overcomes the alignment difficulties arising from the proximity and aperture coupled feeding structures. The CST simulation results, analytic results and measurement ones show good agreement with each other. Moreover, a new miniaturization technique which is based on using High Impedance Wire (HIW) structures has been introduced. Due to their artificial high permeability properties, using proposed method, someone may miniaturize conventional patch antenna without bandwidth and efficiency corruption. Applying suggested method to the proposed antenna structure, two different feeding structures have been designed and compared. Finally, by using AMC structures to load HIW, more miniaturization factor has been achieved.

In today's world, quality improvement of basic medical education is a must for training physicians who are able to meet the growing health needs of our society. One way for quality assurance in higher education including medical education is to develop a system of accreditation which has been in medical education authorities' constant focus recently. This article is a review of national accreditation system of LCME, AMC, AMFEM and international accreditation system of WFME. In these systems an autonomous body conducts accreditation. The questionnaires, developed based on established standards, are sent to the institute requesting accreditation. The institute completes its database to fill the questionnaire and reports the results of self study and data analysis to the accreditation body. A team of experts from the accreditation body visits the institute educational facilities and clinical training centers and reports their assessment results to accreditation body. The accreditation body makes final decision on accreditation.

Background: Head and neck squamous cell carcinoma (HNSCC) is the 11th leading cancer by incidence worldwide. Surgery and radiotherapy have been the major treatment for patients with HNSCC while chemotherapy has become an important treatment option for locally advanced HNSCC. Understanding of the molecular mechanisms underlying HNSCC impelled the development of targeted therapeutic agents. The development and combinations of targeted therapies in different cellular pathways may be needed to fulfill the unmet needs of current HNSCC chemotherapy.Results: A series of N3-acyl-N5-aryl-3, 5-diaminoindazoles were synthesized and their anti-proliferative activities were evaluated against human cancer cell lines, Caki, A549, AMC-HN1, AMC-HN3, AMC-HN4, AMC-HN6, and SNU449. The cellular selectivity of compound was obtained by the modification of substituent at N5-aryl group of 3, 5-diaminoindazole.Compound 9a and 9b showed more than 7-fold selectivity for AMC-HN4 and AMC-HN3, respectively.Conclusions: N3-acyl-N5-aryl-3, 5-diaminoindazole analogues can be used as hits in the development of anticancer drug for HNSCC.

Background and Objectives: Splash erosion is recognized as the first stage in a soil erosion process and results from the soil surface bombing by rain drops. Splash erosion is a complex process including the detachment of soil particles by raindrops followed by splash transport of a part of the detached particles.Quantification of splash erosion in the soils with different textures for various combinations of rainfall intensities and antecedent moisture content (AMC) is essential to understand splash erosion processes.The investigation on the splash erosion in the field is often expensive and time-consuming. Rainfall simulation has been used extensively as a cost effective method for soil erosion prediction across a lot of related factors. This study was conducted to investigate splash erosion in relation to rainfall intensity and AMC in different soil textures using the simulated rainfalls.Materials and Methods: Splash erosion was measured in three soil textural classes (sand, silt and clay) and four AMC (from air-dried to saturation conditions) using the four simulated rainfalls (10, 20, 30 and 40 mm h-1 in intensity). Forty-eight experimental units were designed at three replicates and analyzed using the factorial experiment in the completely randomized design. The experimental units were splash boxes with 25 cm × 35 cm dimensions and 5-cm depth. Splash erosion was determined using the accumulation of splashed particles during each rainfall and accordingly drying in 105 °C for 24-h. The physicochemical soil properties were determined using the conventional methods in the laboratory.Splash erosion data were analyzed using the Duncan parametric test for comparison of the effects of soil texture, rainfall intensity and, AMC on the splash erosion. Data were analyzed using the SAS 9.4 software and the diagrams were delineated using the Sigma Plot software.Results: Significant differences were found in the splash erosion among the soil textures (P<0.001), AMC (P<0.001) and rainfall intensity (P<0.001). Silt showed the highest splash erosion (average value 257.2 g/m2) which was related to easy detachment of silt particles and readily transport by returned raindrops.Sand was the most resistant soil texture to splash erosion. Splash erosion in sand soil varied from 35.43 to 152.70 g per m2. There were significant differences interactions between soil texture and rainfall intensity (P<0.001), soil texture and AMC (P<0.001), rainfall intensity and AMC (P<0.001). Splash erosion was positively affected by the rainfall intensity. Silt showed the highest susceptibility the splash erosion with increasing rainfall intensity. Different results were observed for AMC among the soil textures in the splash erosion. With an increase in AMC, splash erosion in the silt significantly increased, while clay showed a negative trend with increasing AMC. Sand didn’t show an obvious difference in the splash erosion with increasing AMC. Splash erosion was significantly affected by the interactions of three variables (soil texture, rainfall intensity and AMC). The highest splash (441.20 g per m2) erosion was observed in Silt for AMC with 50% saturated point under the rainfall intensity of 40 mm h-1 Sand showed the lowest splash (35.43 g per m2) erosion for AMC with 5% saturated point under 10 mm h-1 rainfall intensity.Conclusion: Results of this study indicated that Silt is the most susceptible soil texture to splash erosion.Also, variations of splash erosion in silt texture were larger than other textures. Splash erosion of each soil could be reliably predicted based on the rainfall intensity and antecedent water content.