A Tunable Microstrip Planar Antenna using Truncated Ground Plane for WiFi/LTE2500/WiMAX/5G/C, Ku, K-Band Wireless Applications

Reconfigurable antennas are key candidates for modern wireless communicating devices to perform multiple wireless operations on various frequencies. This paper is introducing a compact yet efficient design of frequency reconfigurable TX-Shaped monopole antenna with truncated ground plane. The substrate used is FR-4 having a height of 1.6mm. Optical reconfiguration technique enables proposed structure to tune to multiple resonant frequencies depending upon ON/OFF state of the switch. In switch ON state, antenna exhibit quad band characteristics in nature by operating at resonant frequencies ranging from (2282-2816MHz), (4525-5053MHz), (11946-14203MHz) and (16200-19180MHz). While in switch OFF state,proposed structure operates at triple bands having frequencies ranging from (2685MHz-3632MHz), (11985MHz-14234MHz) and (16014-19107MHz). VSWR is calculated less than 1.4 with efficiency ranging from 52.5% to 82.6%, while gain of antenna is calculated ranging (1.62dB-3.53dB). Proposed tunable TX-Shaped structure is able to serve wireless services that includes Wi-Fi (2400-2480MHz), LTE2500 (2500-2690MHz), WIMAX (3300-3800MHz), FCC allocated mid band for 5G (2500MHz/3500MHz) and Satellite Communication applications in IEEE bands that includes Cband (2000-4000MHz), Ku-band (12000-18000MHz) and K-band (18000MHz-27000MHz). Proposed frequency reconfigurable TX-Shaped antenna is low cost, low profile, lightweight and can be used in wireless devices i.e. IPADs, Mobile Phones, 5G device, Tablets, Wi-Fi routers etc. Design and evaluation of antennas’ parameters is observed and analyzed in CST Microwave Studio using Finite Integration Technique (FIT)

A Critical Review of the Objections of the Orientalists to Islamic Civilization and Values

Orientalism has been involved in spreading propaganda against Islam from its beginning. Orientalists (sometimes in the form of researchers, sometimes in the form of businessmen and sometimes in form of religious scholars) collect information about Islam, Prophet of Islam and the Islamic world. On the base of this information, they attack on different aspects of Islam with their fabricated and self-made propaganda. In this Article a critical analysis of Orientalists objections about Islamic Culture and civilization is presented. In the beginning, the Orientalists who researched the Islamic civilization have been reviewed.  Later, the objections of the Orientalists to the veiling of Muslim women, the misinterpretation of the veil, the attempts to associate the veil with the elite, the presentation of the veil as a custom instead of the order of the Islamic Sharia and the efforts of the Orientalists to disparage Islamic morals and dignity through painting has been reviewed.  The article discusses the spectacle of the snake charmer, the sale of naked women in slave markets, half-naked maids in Moroccan baths, and images of extrajudicial executions

Performance Enhancement of Wearable Antenna Using High Impedance Surfaces

This paper presents a novel textile wearable antenna that has been designed to operate at Wi-Fi bands of 2.4GHz & 5.8GHz. Antenna performance in free space environment showed Gain of 1.8dBi at 2.4GHz and 4.5dBi at 5.8GHz. However, performance deteriorated when antenna was operated near human body which is lossy and complex in nature. For mitigating the human body effect on antenna performance, high impedance surface (HIS) was designed and integrated with this textile antenna. Due to shielding effect of HIS, antenna Gain increased to 8dBi at 2.4GHz and 9dBi at 5.8GHz. The SAR values were also reduced to 0.682W/Kg at 2.4GHz and 0.0692W/Kg at 5.8GHz for 10g tissue. The proposed antenna was also tested under bending and crumpling conditions. It was observed that antenna performance was not significantly deteriorated. The proposed textile antenna can have exciting applications in emerging wearable technologies

Improvement in the Gain of UWB Antenna for GPR Applications by Using Frequency-Selective Surface

In this article, high-gain ultra-wideband (UWB) monopole antenna is presented. e UWB monopole antenna is a semicircular- shaped antenna with a semicircular slot at the top side. e bottom plane consists of partial ground with triangular and rectangular slotted structures to improve the impedance bandwidth of the proposed antenna. In order to enhance gain, a 6 × 6 metallic reector (FSS) is placed below the antenna. e performance of the oered design is validated experimentally. e simulated results show resemblance with the measured results. e antenna resonates for the UWB ranging from 3 to 11 GHz. Moreover, the integration of FSS improves the average gain by 4 dB, where peak gain obtained is 8.3 dB across the UWB. In addition, the reported unit cell having dimension of 0.11lambda × 0.11lambda gives wide bandwidth (7.2 GHz) from 3.3 GHz to 10.5 GHz. e performance of the proposed antenna determines its suitability for the modern day wireless UWB and GPR applications.Dr. Mohammad Alibakhshikenari acknowledges support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 801538

Passive control of base drag employing dimple in subsonic suddenly expanded flow

This paper presents an experimental and computational investigation to study the effectiveness of dimples to control the base pressure in Backward facing step (BFS) for various Nozzle pressure ratio (NPR) having Compressible flow to minimize the base drag. Two dimples of 3 mm diameter located at 1800 interval along pitch circle diameter of 23 mm in the base region was employed as passive controls. The test was conducted for NPR 1.27, 1.38, 1.52 and 1.69. The model is designed in such a way so as to provide four BFS with angle of incidence as 150 from which the flow suddenly expands to a square duct of 25 mm. The experimental investigation is carried out for different length of duct 4D≤L≤10D to see the influence of geometric parameter on base pressure. From the present investigation, it was found that dimples as passive control is very effective at higher NPR and the wall pressure distribution too was quite stable at higher NPR. Also the geometric parameter was found to influence the base pressure for a particular NPR. Computational investigation using commercial CFD tool shows pressure and velocity distribution profile for both dimple and non-dimple control. Tests are carried out by using Navier-stokes equation, Turbulence model as SST, Reynolds number (Re) =122.56×103. From this investigation it is clear that for a given nozzle pressure ratio one can find optimum L/D ratio which will result in maximum increase/decrease of base pressure and dimples can be effective passive controller for reducing base drag without disturbing the flow field

Optimization of accurate estimation of single diode solar photovoltaic parameters and extraction of maximum power point under different conditions

Introduction. With the snowballing requirement of renewable resources of energy, solar energy has been an area of key concern to the increasing demand for electricity. Solar photovoltaic has gotten a considerable amount of consideration from researchers in recent years. Purpose. For generating nearly realistic curves for the solar cell model it is needed to estimate unknown parameters with utmost precision. The five unknown parameters include diode-ideality factor, shunt-resistance, photon-current, diode dark saturation current, and series-resistance. Novelty. The proposed research method hybridizes flower pollination algorithm with least square method to better estimate the unknown parameters, and produce more realistic curves. Methodology. The proposed method shows many promising results that are more realistic in nature, as compared to other methods. Shunt-resistance and series-resistance are considered and diode constant is not neglected in this approach that previously has been in practice. The values of series-resistance and diode-ideality factor are found using flower pollination algorithm while shunt-resistance, diode dark saturation current and photon-current are found through least square method. Results. The combination of these techniques has achieved better results compared to other techniques. The simulation studies are carried on MATLAB/Simulink.Вступ. З огляду на величезну потребу у відновлюваних енергетичних ресурсах, сонячна енергія стала ключовою сферою розв’язання проблеми зростання попиту на електроенергію. За останні роки сонячна фотоелектрична техніка отримала значну увагу з боку дослідників. Мета. Для створення майже реалістичних кривих для моделі сонячних батарей необхідно оцінити невідомі параметри з максимальною точністю. П'ять невідомих параметрів включають коефіцієнт ідеальності діодів, опір шунту, фотонний струм, струм темного насичення діодів і послідовний опір. Новизна. Запропонований метод дослідження поєднує алгоритм запилення квітів із методом найменших квадратів для кращої оцінки невідомих параметрів та отримання більш реалістичних кривих. Методологія. Запропонований метод демонструє багато перспективних результатів, які є більш реалістичними за своєю природою, порівняно з іншими методами. Розглянуто опір шунта і послідовний опір, і в цьому підході, який раніше застосовувався на практиці, не нехтують постійною діода. Значення послідовного опору та коефіцієнта ідеальності діодів визначаються за допомогою алгоритму запилення квіток, тоді як опір шунту, струм темного насичення діодів і фотонний струм - методом найменших квадратів. Результати. Поєднання цих методів забезпечило кращі результати у порівнянні з іншими методами. Моделювання проводиться на MATLAB/Simulink

Potential application of Conyza canadensis (L) Cronquist in the management of diabetes: In vitro and in vivo evaluation

Purpose: To investigate the antihyperglycemic activity of Conyza canadensis via α-glucosidase inhibition in alloxan-induced diabetic mice.Methods: In vitro antidiabetic activity was investigated using α-glucosidase inhibition assay with acarbose (62.5, 125, 500 and 1000 μg/ml) as the standard drug. Conyza canadensis crude extract (Cc.Cr) in doses of 10, 30, 100 and 300 mg/kg were administered daily as a single dose to alloxaninduced (200 mg/kg) diabetic mice (Balb/c), and its effect on fasting blood glucose levels and body weight were evaluated for 15 consecutive days; oral glucose tolerance test was conducted. Metformin (500 mg/kg) was used as a standard antidiabetic drug for comparison. Acute toxicity of Cc.Cr was also evaluated at doses of 3 and 5 g/kg.Results: Conyza canadensis crude extract (Cc.Cr) exhibited strong enzyme inhibition at concentrations (μg/ml) of 1000 (74.78 ± 0.92), 500 (65.11 ± 0.07), 250 (57.55 ± 0.41), 125 (51.55 ± 0.67) and 62.5 ( 44.00 ± 0.57), with a median inhibitory concentration (IC50) of 107 μg/ml. Cc.Cr at all test doses (10 - 300 mg / kg) reduced fasting blood glucose levels in alloxan (200 mg/kg) - induced diabetic mice on days 5, 10 and 15 compared to the diabetic control group (p < 0. 001). These effects were similar to those caused by the standard antidiabetic drug, metformin. Cc.Cr at all test doses also increased body weight of treated animals. The extract (300 mg/kg) significantly improved tolerance of oral glucose overload in mice, like metformin. The extract did not cause any mortality up to the maximum dose of 5 g/kg.Conclusion: The results reveal that Conyza canadensis possesses potent secondary metabolites which can cause inhibition of α-glucosidase. Moreover, the plant extract has the ability to reduce blood glucose level in diabetic animals and significantly improves oral glucose overload tolerance.Keywords: Conyza canadensis, α-Glucosidase, Blood glucose, Alloxan, Diabetes, Glucose toleranc

Wideband and High Gain Array Antenna for 5G Smart Phone Applications Using Frequency Selective Surface

This work presents an eight element array antenna with single layer frequency selective surface (FSS) to obtain high gain. The eight elements are fed by single port. The FSS consists of 14 × 6 unit cells with one unit cell size is 5 × 5 mm2 having wideband behavior. The antenna uses Rogers RT Duroid 5880 substrate and giving very wide bandwidth from 20 GHz to 65 GHz, covering millimeter wave 5G bands (including 28 GHz, 38 GHz and 60 GHz). The designed FSS is showing stop band transmission characteristics below −10 dB threshold from 25 GHz to 42 GHz and 59 GHz to 61 GHz. The eight element antenna integrated with the FSS reflector, which results an improvement in the gain level from 12 dB to 15 dB at 28 GHz, from 10 dB to 12 dB at 38 GHz, and from 9.5 to 11 dB at 60 GHz. The dimensions of the antenna are 65 × 27 × 0.857 mm3. The proposed antenna shows stable gain and directional radiation patterns. The simulation findings are experimentally confirmed, by testing the fabricated prototypes of the proposed antenna system

Patch antenna directivity analysis using an equi-area method

The widespread exploitation of mobile cellular phones and use of wireless devices such as PDAs, in-vehicle Global Positioning System (GPS) receivers, and the future deployment of mobile satellite digital audio and video has developed a re-energized interest in efficient and accurate measurement techniques for antennas. This paper demonstrates directivity analysis of a patch antenna using a new fast, rotation-invariant spherical near-field antenna measurement technique. The method is based on an equi-area surface partitioning algorithm. The paper evaluates the sampling technique’s performance when compared with a normal spherical near-field measurement technique using equal angle sampling