This article describes the CPW-feed ultra wideband tree type monopole fractal antenna and it’s backscattering. The prototype antenna is fabricated with optimized dimension. The experimental result of this antenna exhibits the ultra wideband characteristics from 5.0 GHz to 14.0 GHz. The experimental and simulated results are in good agreement. The effects of various design parameters on impedance bandwidth have also been studied in detail using EM simulator. The nature of H and E - plane radiation patterns are omni-directional and bidirectional respectively. The measured group delay is almost constant throughout band. This indicates the phase linearity. The monostatic RCS of antenna is also simulated iteration-wise for antenna and structural scattering mode. This antenna can be useful for UWB system, Microwave Imaging and vehicular radar and military high data rate wireless communications.

This paper presents the design of notched-band antenna with CPW - feed. The notched - band has been achieved by using the W-shape slot in ground plane. The antenna has been simulated using a 3D - Electromagnetic simulator. The experimental results of proposed antenna exhibit ultra wideband characteristics from 2.0 - 15.0 GHz except the notched-band frequency from 5.0 - 6.0 GHz. The slot is optimized with respect to width, length and position for a detailed study of notched-band characteristics. It is observed that the centre frequency and bandwidth of notched-band depend on the length and width of slot respectively. The experimental radiation patterns of this antenna are omni-directional in H-plane and bidirectional in E-plane. This antenna can be useful for UWB system, medical imaging and vehicular radar.

This paper presents the design of a nano-arm fractal antenna suitable for ultra wide band applications. The CPW-feed and fractal concept have been used to achieve the ultra wide bandwidth. The shape of the fractal geometry, the number of iterations and the number of nano-arms are the deciding factors for achieving wider impedance bandwidth. The experimental result of the fractal antenna exhibits ultra wideband characteristics in the frequency range of 2.55 GHz to 11.84 GHz corresponding to an impedance bandwidth of 131.77%. The measured radiation patterns of the proposed antenna are nearly omni-directional in the H - plane and bidirectional in the E-plane. The antenna can be useful for modern wireless communication, medical imaging and ground penetrating radar.

In this paper, single and dual band EBG structures for wider bandwidth are proposed. In each of the discussed EBGs, a metallic patch of regular geometry is chosen for the unit element. The patch is further modified by cutting slots to get extra inductance and capacitance which results into lower cut-off frequency and larger bandwidth. The proposed EBG structures are compared with the standard mushroom type EBG with respect to surface wave attenuation. The -20 dB cut-off frequencies and bandwidths of the various EBGs are compared. The effect of unit element size, gap between unit elements and via diameter on the transmission response is presented. Among the discussed EBGs, the swastika type structure is compact, single band and has wider bandwidth. The square patch with a single disconnected loop type slot EBG and the Fractal EBG are dual band. While square patch is more compact, the fractal EBG has wider bandwidth. All the EBGs can be useful in the design of antenna and other microwave circuits.

AbstractA compact (20 x 20 mm2 size), coplanar waveguide (CPW) fed, octagonal slotted, dual-band antenna is presented in this paper. The proposed antenna has a simple structure consisting of an octagonal slot, L-shape stub, and a two stepped rectangular patch. The introduction of the L-shaped metallic stubs in the ground plane generates a lower resonance frequency at 2.42 GHz. The proposed antenna is fabricated on a low cost FR4 substrate having thickness of 1.6 mm. The measured impedance bandwidth of the proposed antenna is from 2.40 to 2.46 GHz and 3.2 to 6.2 GHz. It is also shown that the proposed antenna has stable radiation patterns of almost dumb-bell shape in the E-plane and omni-directional shape in the H-plane. The effects of various design parameters on the impedance bandwidth are also studied and presented in detail. The proposed antenna can be used for 3.5/5.5 GHz worldwide interoperability for microwave access (WiMAX), 2.4/5.2/5.8 GHz wireless local area network (WLAN) and 3.1-6.0 GHz Direct-Sequence Code Division Multiple Access (DS-CDMA) / Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) ultra wideband (UWB) applications.

Residual solvents in pharmaceutical samples are monitored using gas chromatography with head space. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients (API). The analysis of residual organic solvents (methanol, acetone, cyclohexane, dichloromethane, toluene) in Omeprazole, an active pharmaceutical ingredient was investigated. Omeprazole is a potent reversible inhibitor of the gastric proton pump H+/K+-ATPase. The Head space gas chromatography (HSGC) method described in this investigation utilized a SPB TM-624, Supelco, 30 m long x 0.25 mm internal diameter, 1.4µm-thick column. Since Omeprazole is a thermally labile compound, the selection of the proper injector temperature is critical to the success of the analysis. The injector temperature was set at 170ºC to prevent degradation. The initial oven temperature was set at 40ºC for 12 min and programmed at a rate of 10ºC min-1 to a final temperature of 220ºC for 5 min. Nitrogen was used as a carrier gas. The sample solvent selected was N,N-dimethylacetamide. The method was validated to be specific, linear, precise, sensitive, rugged and showed excellent recovery.

Abstract DBW222 is characterized by potential yield of 8210 kg ha-1 under high fertility when sown in timely conditions in North India. It possesses better agronomic attributes and has better adaption to sowing time, high rust resistance, quality attributes, and lodging tolerance because of a shorter 2nd internode and wider diameter.

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion.