Multi-band OFDM UWB receiver with narrowband interference suppression

A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system is limited to -41.3 dBm/MHz in order to not interfere existing narrowband systems. Moreover, it must operate even in the presence of unintentional radiation of FCC Class-B compatible devices. If this unintentional radiation resides in the UWB band, it can jam the communication. Since removing the interference in digital domain requires higher dynamic range of analog front-end than removing it in analog domain, a programmable analog notch filter is used to relax the receiver requirements in the presence of NBI. The baseband filter is placed before the variable gain amplifier (VGA) in order to reduce the signal swing at the VGA input. The frequency hopping period of MB-OFDM puts a lower limit on the settling time of the filter, which is inverse proportional to notch bandwidth. However, notch bandwidth should be low enough not to attenuate the adjacent OFDM tones. Since these requirements are contradictory, optimization is needed to maximize overall performance. Two different NBI suppression schemes are tested. In the first scheme, the notch filter is operating for all sub-bands. In the second scheme, the notch filter is turned on during the sub-band affected by NBI. Simulation results indicate that the UWB system with the first and the second suppression schemes can handle up to 6 dB and 14 dB more NBI power, respectively. The results of this work are not limited to MB-OFDM UWB system, and can be applied to other frequency hopping systems

Multi-band OFDM UWB receiver with narrowband interference suppression

A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system is limited to -41.3 dBm/MHz in order to not interfere existing narrowband systems. Moreover, it must operate even in the presence of unintentional radiation of FCC Class-B compatible devices. If this unintentional radiation resides in the UWB band, it can jam the communication. Since removing the interference in digital domain requires higher dynamic range of analog front-end than removing it in analog domain, a programmable analog notch filter is used to relax the receiver requirements in the presence of NBI. The baseband filter is placed before the variable gain amplifier (VGA) in order to reduce the signal swing at the VGA input. The frequency hopping period of MB-OFDM puts a lower limit on the settling time of the filter, which is inverse proportional to notch bandwidth. However, notch bandwidth should be low enough not to attenuate the adjacent OFDM tones. Since these requirements are contradictory, optimization is needed to maximize overall performance. Two different NBI suppression schemes are tested. In the first scheme, the notch filter is operating for all sub-bands. In the second scheme, the notch filter is turned on during the sub-band affected by NBI. Simulation results indicate that the UWB system with the first and the second suppression schemes can handle up to 6 dB and 14 dB more NBI power, respectively. The results of this work are not limited to MB-OFDM UWB system, and can be applied to other frequency hopping systems

Atmospheric Pressure Mass Spectrometry of Single Viruses and Nanoparticles by Nanoelectromechanical Systems

Mass spectrometry of intact nanoparticles and viruses can serve as a potent characterization tool for material science and biophysics. Inaccessible by widespread commercial techniques, the mass of single nanoparticles and viruses (>10MDa) can be readily measured by NEMS (Nanoelectromechanical Systems) based Mass Spectrometry, where charged and isolated analyte particles are generated by Electrospray Ionization (ESI) in air and transported onto the NEMS resonator for capture and detection. However, the applicability of NEMS as a practical solution is hindered by their miniscule surface area, which results in poor limit-of-detection and low capture efficiency values. Another hindrance is the necessity to house the NEMS inside complex vacuum systems, which is required in part to focus analytes towards the miniscule detection surface of the NEMS. Here, we overcome both limitations by integrating an ion lens onto the NEMS chip. The ion lens is composed of a polymer layer, which charges up by receiving part of the ions incoming from the ESI tip and consequently starts to focus the analytes towards an open window aligned with the active area of the NEMS electrostatically. With this integrated system, we have detected the mass of gold and polystyrene nanoparticles under ambient conditions and with two orders-of-magnitude improvement in capture efficiency compared to the state-of-the-art. We then applied this technology to obtain the mass spectrum of SARS-CoV-2 and BoHV-1 virions. With the increase in analytical throughput, the simplicity of the overall setup and the operation capability under ambient conditions, the technique demonstrates that NEMS Mass Spectrometry can be deployed for mass detection of engineered nanoparticles and biological samples efficiently.Comment: 38 pages, 6 figure

Ichthyofauna of Aksaray province (Turkey)

Özet Aksaray ili ihtiyofaunasını belirlemek amacıyla Eylül 2015-Ağustos 2018 tarihleri arasında yapılan arazi çalışmaları sonucunda Aksaray ilinde 11 familyaya ait 19 tür tespit edilmiştir. Bunlar; Anatolichthys anatoliae, Atherina boyeri, Capoeta mauricii, C. tinca, Cobitis turcica, Cyprinus carpio, Gambusia holbrooki, Gobio gymnostethus, Oxynoemacheilus eregliensis, O. angorae, Oncorhynchus mykiss, Paraphanius similis, Pseudophoxinus crassus, Sander lucioperca, Seminemacheilius ekmekciae, Silurus glanis, Squalius cappadocicus, S. pursakensis ve Tinca tinca. Bu türlerden A. anatoliae, P. similis, C. mauricii, C. tinca, C. turcica, G. gymnostethus, O. eregliensis, O. angorae, P. crassus, S. cappadocicus, S. pursakensis ve S. ekmekciae endemik türlerdir. Squalius pursakensis, C. tinca, O. mykiss, O. angorae ve G. holbrooki ise il için yeni kayıt niteliği taşımaktadır.As a result of the field studies carried out between September 2015 and August 2018, 19 species, including 11 families, were identified to determine the Ichthyofauna of Aksaray. These are Anatolichthys anatoliae, Atherina boyeri, Capoeta mauricii, C. tinca, Cobitis turcica, Cyprinus carpio, Gambusia holbrooki, Gobio gymnostethus, Oxynoemacheilus eregliensis, O. angorae, Oncorhynchus mykiss, Paraphanius similis, Pseudophoxinus crassus, Sander lucioperca, Seminemacheilius ekmekciae, Silurus glanis, Squalius cappadocicus, S. pursakensis, and Tinca tinca. Of these species, A. anatoliae, P. similis, C. mauricii, C. tinca, C. turcica, G. gymnostethus, O. eregliensis, O. angorae, P. crassus, S. cappadocicus, S. pursakensis, and S. ekmekciae are endemic species. Squalius pursakensis, C. tinca, O. mykiss, O. angorae, and G. holbrooki species are new records for the province

Freshwater fish fauna of Aksaray

This study was carried out from February and August 2016 in order to determine freshwater fish fauna of Aksaray. As a result of the systematic investigation of the samples obtained from the field studies 10 species belonging to 5 families were determined. The species are Aphanius anatoliae, Capoeta pestai, Cobitis turcica, Cyprinus carpio, Gobio gymnostethus, Gambusia holbrooki, Oxynoemacheilus angorae, Pseudophoxinus crassus, Tinca tinca, Squalius cappadocicus. According to the IUCN categories C. pestai, C. turcica and P. crassus are EN, S. cappadocicus and G. gymnostethus are CR, A. anatoliae are NT, O. angorae, T. tinca and G. holbrooki are LC

Determination of some population dynamical parameters of planiliza abu (heckel, 1843) from Ceyhan river basin

This study was carried out in order to determine population parameters of Planiliza abu in August 2014, May and July 2015 in Azaplı Lake and Kartalkaya Dam Lake, Ceyhan River Basin. A total of 370 specimens were analyzed. Age of the specimens ranged from 0 to VI. age groups and dominant age group was III (30.81%). Total length varied from 4.0-23.1 cm with the mean of 14.17±3.11 cm and total weight ranged from 1.06 to 160.10 with the mean of 39.49±24.95 g. Length-weight relationship were estimated W=0.0114L . Estimated population parameters were calculated as L ∞ : 27.87 cm, k: 0.189 year -1 , t : -1.09 year, Φꞌ: 2.89 and K: 1.13 for the population. Mortality and exploitation rates were also estimated as Z: 0.40, M: 0.33, F: 0.07 and E: 0.17, respectively. In the light of these values there were no over fishing pressure on the population. o 3.022Bu çalışma Ağustos 2014, Mayıs ve Temmuz 2015 tarihlerinden Ceyhan Havzasında yer alan Azaplı Gölü ve Kartalya Barajındaki Planiliza abu populasyonuna ait parametrelerin belirlenmesi amacıyla yapılmıştır. Örneklenen 370 bireyin yaşlarının 0 ile VI. yaş grupları arasında değişim gösterdiği ve baskın olan yaş grubunun III. yaş grubu (%30,81) olduğu belirlenmiştir, Çalışmada kullanılan bireylerin 4,0-23,1 cm total boya ve 1,06-160,10g total ağırlığa sahip oldukları belirlenmiş olup ortalama boy ve ağırlık değerleri ise sırasıyla 14,17±3,11 cm ve 39,49±24,95 g olarak hesaplanmıştır. Boy-ağırlık ilişkisi W=0,0114L 3,022 ve bazı populasyon parametreleri ise L∞: 27,87 cm, k: 0,189 yıl-1 , to : -1,09 yıl, Φꞌ: 2,89 ve K: 1,13 olarak tahmin edilmiştir. Ölüm oranları ve sömürülme düzeyi ise Z: 0,40, M: 0,33, F: 0,07 ve E: 0,17 olarak hesaplanmış olup bu veriler ışığında populasyon üzerinde herhangi bir av baskısının söz konusu olmadığı ortaya çıkmaktadır

SEPIC Converter with an LC Regenerative Snubber for EV Applications

A Single-Ended Primary-Inductor Converter (SEPIC) converter with an Inductor-Capacitor (LC) regenerative snubber is proposed to reduce Electromagnetic Interference (EMI) for Electric Vehicle (EV) applications. The switching energy is transferred through a capacitor to an inductor which is coupled to SEPIC inductors. This technique reduces the number of components and also returns some of switching energy to SEPIC converter. The mathematical analysis and optimization of LC snubber with respect to number of turns is also presented. Spice simulations and experimental results are provided to verify its performance. The proposed LC regenerative snubber reduces the peak voltage by 16 V on the switching transistor during the switching transient. It is also indicated that 8 dB reduction is achieved in the EMI measurements at ringing frequency and 10 dB reduction at high frequency band

Atmospheric pressure mass spectrometry of single viruses and nanoparticles by nanoelectromechanical systems

Mass spectrometry of intact nanoparticles and viruses can serve as a potent characterization tool for material science and biophysics. Inaccessible by widespread commercial techniques, the mass of single nanoparticles and viruses (>10MDa) can be readily measured by nanoelectromechanical systems (NEMS)-based mass spectrometry, where charged and isolated analyte particles are generated by electrospray ionization (ESI) in air and transported onto the NEMS resonator for capture and detection. However, the applicability of NEMS as a practical solution is hindered by their miniscule surface area, which results in poor limit-of-detection and low capture efficiency values. Another hindrance is the necessity to house the NEMS inside complex vacuum systems, which is required in part to focus analytes toward the miniscule detection surface of the NEMS. Here, we overcome both limitations by integrating an ion lens onto the NEMS chip. The ion lens is composed of a polymer layer, which charges up by receiving part of the ions incoming from the ESI tip and consequently starts to focus the analytes toward an open window aligned with the active area of the NEMS electrostatically. With this integrated system, we have detected the mass of gold and polystyrene nanoparticles under ambient conditions and with two orders-of-magnitude improvement in capture efficiency compared to the state-of-the-art. We then applied this technology to obtain the mass spectrum of SARS-CoV-2 and BoHV-1 virions. With the increase in analytical throughput, the simplicity of the overall setup, and the operation capability under ambient conditions, the technique demonstrates that NEMS mass spectrometry can be deployed for mass detection of engineered nanoparticles and biological samples efficiently