Seven-band ultra-thin terahertz metamaterial absorber at 0.3-0.5 THz frequency

Circuit World ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Elakkiya A. ◽  
Radha Sankararajan ◽  
Sreeja B.S.
Keyword(s):  
Normal Incidence ◽  
Unit Cell ◽  
Planar Structure ◽  
Geometrical Parameters ◽  
Frequency Range ◽  
Content Type ◽  
Absorption Performance ◽  
Thz Range ◽  
High Level ◽  
First Time

Purpose The proposed structure consists of copper as a ground plane and 50 µm polyimide dielectric layer is placed in between the ground panel and top radiating patch. Octagon and pentagon shapes are combined to form a unit cell. This structure exhibits seven absorption peaks within the short frequency range 0.3–0.5 terahertz (THz) without any interference. Under normal incidence, this structure achieves the absorption of 96.9%, 95.3%, 98.7%, 91.7%, 96.5%, 95% and 97.8% at 0.3136 THz, 0.377 THz, 0.4060 THz, 0.4085 THz, 0.4240 THz, 0.4436 THz and 0.4648 THz, respectively. This study aims to provide a range of applications in THz dielectric sensing, thickness sensing, communications, wavelength selective radiation and detecting. Design/methodology/approach Multi-band THz metamaterial absorbers (MMA) from previous research are having a large unit size because of the presence of stacked layers and multiple resonators within a single unit cell. This leads to difficulty while implementing in practical applications. In this study, a new MMA has been presented at seven distinct frequencies without using stacked layers and multiple resonators. Findings This structure exhibits seven absorption peaks within the short frequency range 0.3–0.5 THz without any interference. Under normal incidence this structure achieves the absorption of 96.9%, 95.3%, 98.7%, 91.7%, 96.5%, 95% and 97.8% at 0.3136 THz, 0.377 THz, 0.4060 THz, 0.4085 THz, 0.4240 THz, 0.4436 THz and 0.4648 THz, respectively. The polarization and angle insensitivity of the design have been validated by numerical simulation up to 90° of oblique incidence. The effects of variation in geometrical parameters on absorption response are demonstrated. The physical mechanism of the structure is analysed by electric and magnetic field distributions. The resonant frequency ranges and the number of bands in this work are compared with previously reported papers. In THz range, this is the first time a single planar structure provides seven-band high-level absorption performance. Originality/value The highlights of the proposed seven-band THz MMA structure, in comparison with previous THz metamaterials, are as follows: this has a simple unit-cell structure and high resonant mechanism within the short frequency range 0.3–0.5 THz; this MMA can provide seven-band high-level absorption performance in a single planar structure for the first time in THz range; and this structure is polarization and incident angle independent in nature.

US charges designed to make Russia hacking irrefutable

2018 ◽  
Keyword(s):  
Democratic Party ◽  
Content Type ◽  
White House ◽  
Russian State ◽  
The Us ◽  
Us Government ◽  
Social Media Platforms ◽  
To Come ◽  
High Level ◽  
First Time

Subject The US indictment of Russian intelligence officers. Significance The latest indictment to come out of the investigation led by Special Counsel Robert Mueller is the most striking yet as it targets Russian state actors for the first time. It sets out charges of hacking into Democratic Party networks, stealing more than 50,000 documents and using them for disruptive purposes in the 2016 US presidential election. Despite the considerable level of detail in the evidence offered, the White House has yet to address publicly the issues raised or confronting Russia. Impacts US government, election software providers, parties and social media platforms will face pressure to prepare for the midterm elections. Detailed attribution of cyber interference will likely weaken the notion that perpetrators enjoy a high level of plausible deniability. Hackers will continue to employ 'spearphishing' for its simplicity, success rate and cost-effectiveness.

scholarly journals Innovative outcome through exploration and exploitation – Enablers, barriers and industrial property

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nancy Vargas ◽  
M. Begoña Lloria ◽  
Addisson Salazar ◽  
Luis Vergara
Keyword(s):  
Positive Impact ◽  
Exploration And Exploitation ◽  
Economic Sectors ◽  
Industrial Property ◽  
Content Type ◽  
Close Relationship ◽  
Relationship Model ◽  
High Level ◽  
First Time ◽  
Positive Effect

PurposeThis research aims to study the effect of R&D (research and development) enablers and barriers as well as industrial property on exploration, their influence on exploitation and finally the possible impact on innovative outcome (IO) as a result variable. The IO can be defined as the orientation towards new or improved products, services and processes, as well as towards penetration and greater market share, which the company has obtained as a result of innovative processes.Design/methodology/approachFor this purpose, a new relationship model is defined, which is empirically contrasted in a quantitative study. We use a sample of large firms from different economic sectors with a high level of investment in R&D.FindingsThe results indicate a close relationship between exploration and exploitation processes, as well as a positive impact on the innovative outcome. Moreover, the type of relationship that R&D enablers and barriers have with exploration is demonstrated and the lack of a positive effect of industrial property on exploration.Practical implicationsThese results may lead to new markets opening up and the creation or improvement of new products, services or processes in diverse sectors of highly innovative firms.Originality/valueThis research aims to study the effect of R&D enablers and barriers and industrial property on learning flows and, finally, the possible impact on the innovative outcome. A new theoretical model of relationships is defined, and it is the first time that it is empirically tested.研究目的本研究旨在探討研究與開發的推動者、研發的障礙和工業產權對探索與開發的影響，並最終探究出其可能對作為結果變項的創新成果帶來的影響。創新成果可解釋為邁向新的或改良的產品，服務和流程的定向，以及邁向滲透和更大的市場份額的定向，而這更大的市場份額是企業的創新流程所帶來的。研究的設計/方法/理念為達研究目的，我們解說了一個新的關聯模型, 並使用於一項量化研究，進行以實驗為依據的對比。我們使用的樣本，包括來自不同經濟領域，並於研發投放高水平投資的大企業。研究結果研究結果顯示，探索與開發是兩個關係密切的流程；研究結果亦顯示對創新成果的影響是正面的。而且，結果展示了研發推動者、研發障礙兩者與探索的關聯，以及工業產權對探索是欠缺正面作用的。實際的意義研究結果或會帶來新市場的開拓，以及在不同領域、高度創新的企業內，帶來新的產品，服務與流程的創造和改良。研究的原創性和價值本研究旨在探討研發推動者，研發障礙和工業產權對學習心流的影響，並最終探究出其對創新成果可能帶來的影響。研究解說了一個新的、純理論的關聯模型，而這個模型於此是首次憑實驗而被測試的。

Results of recording electrophysiological signals by nanosensors during tests on volunteers

Sensor Review ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 335-346
Author(s):  
Diana K. Аvdeeva ◽  
Wenjia Guo ◽  
Dang Quang Nguyen ◽  
Mikhail M. Yuzhakov ◽  
Ivan L. Ivanov ◽  
...  
Keyword(s):  
Real Time ◽  
Impulse Activity ◽  
High Sensitivity ◽  
Simultaneous Recording ◽  
P Wave ◽  
Frequency Range ◽  
Content Type ◽  
Software Complex ◽  
Electrophysiological Signals ◽  
First Time

Purpose The purpose of this paper is to analyze the results of recording electrophysiological signals by nanosensors during tests on volunteers using neutral questions and questions that cause excitement. Design/methodology/approach The nanosensor-based hardware and software complex (HSC) was used for simultaneous recording of electrocardiogram, electroencephalogram and galvanic skin response during tests on volunteers using neutral questions and questions that cause excitement. The recording was carried out in real time without averaging and filtering in the extended frequency range from 0 to 10,000 Hz, level of more than 1 µV and sampling frequency equal to 64 kHz. Findings For the first time, the following signals were recorded by nanosensors without filtering and averaging in the measuring channels: real-time micropotentials on an electrocardiogram with a duration of 0.2 ms and a level of 1 µV or more. Also, for the first time, changes in the shape and amplitude of the P wave, slow waves on the electroencephalography (EEG), high impulse activity of the EEG and impulse activity of short duration on the GSR were recorded in response to questions that cause excitement. Practical implications The obtained results will be used for high-resolution equipment to develop additional measuring channels in existing types of equipment for psychophysiological studies. Originality/value For the first time, new data undistorted by filters was obtained on the amplitude and time parameters of electrophysiological signals in the frequency range from 0 to 10,000 Hz in response to questions that cause excitement, which was due to high sensitivity and noise immunity of nanosensors in comparison with existing electrodes for biopotential recording.

scholarly journals First Report of Klebsiella oxytoca Strain Coproducing KPC-2 and IMP-8 Carbapenemases

2011 ◽  
Vol 55 (6) ◽  
pp. 2937-2941 ◽  
Author(s):  
Bin Li ◽  
Jing-Yong Sun ◽  
Qing-Zhong Liu ◽  
Li-Zhong Han ◽  
Xin-Hong Huang ◽  
...  
Keyword(s):  
Southern Hybridization ◽  
Klebsiella Oxytoca ◽  
Content Type ◽  
Genetic Environment ◽  
Carbapenem Resistant ◽  
Plasmid Analysis ◽  
High Level ◽  
Lactamase Gene ◽  
First Time ◽  
Level Resistance

ABSTRACTThe study shows for the first time the presence of theKlebsiella oxytocastrain fp10 coproducing plasmid-mediated KPC-2 and IMP-8 carbapenemases. The strain was obtained from the fecal sample of an inpatient and showed high-level resistance to imipenem and ertapenem (MICs > 32 μg/ml). Conjugation experiments demonstrated the transferability of the carbapenem-resistant determinants. The results of plasmid analysis and Southern hybridization revealed that theblaKPC-2gene was located on transferable plasmid pFP10-1 (∼54 kb), whereas theblaIMP-8gene was on transferable plasmid pFP10-2 (∼180 kb). Analysis of the genetic environment of these two genes has demonstrated that ISKpn6and ISKpn8are involved in the spread of theblaKPC-2gene, while the transposable elements IS26,intI1, andtniCmight contribute to the dissemination of theblaIMP-8gene. The chimera of several transposon-associated elements indicated a novel genetic environment of IMP-type metallo-β-lactamase gene inEnterobacteriaceaefrom China.

scholarly journals Emergence of Proteus mirabilis HarboringblaKPC-2andqnrDin a Chinese Hospital

2012 ◽  
Vol 56 (5) ◽  
pp. 2278-2282 ◽  
Author(s):  
Yan-yan Hu ◽  
Jia-chang Cai ◽  
Rong Zhang ◽  
Hong-wei Zhou ◽  
Qian Sun ◽  
...  
Keyword(s):  
Proteus Mirabilis ◽  
Dna Hybridization ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Quinolone Resistance ◽  
Pfge Analysis ◽  
Content Type ◽  
High Level ◽  
First Time ◽  
Conjugation Experiment

ABSTRACTNineteen carbapenem-nonsusceptibleProteus mirabilisisolates were recovered from intensive care units in the Second Affiliated Hospital of Zhejiang University during a 3-month period. The isolates showed a high level of resistance against ciprofloxacin, in addition to their resistance against the carbapenems. Pulsed-field gel electrophoresis (PFGE) analysis showed that these isolates belonged to three clonal strains. PCRs and DNA sequence analysis of the carbapenemase and other β-lactamase genes indicated that all the isolates harbored theblaKPC-2gene. Twelve of 19 isolates harbored the plasmid-mediated quinolone resistance (PMQR) genes, both theqnrDandaac(6′)-Ib-crgenes. Eight representative isolates with high levels of quinolone resistance carried the similar mutation profiles of S83I ingyrA, E466D ingyrB, and S80I inparC. Reduced carbapenem susceptibility was transferred toEscherichia coli(EC600) in a conjugation experiment, while the quinolone resistance was not. DNA hybridization showed thatqnrDwas located on a plasmid of approximately 4.5 kb. In summary, large clonally related isolates of KPC-2-producingP. mirabilisemerged in a Chinese hospital, andqnrDwas detected in KPC-producingP. mirabilisfor the first time.

scholarly journals Requirements for future digital visitor flow management

2019 ◽  
Vol 5 (3) ◽  
pp. 241-258 ◽  
Author(s):  
Marcel Huettermann ◽  
Tatjana Thimm ◽  
Frank Hannich ◽  
Christine Bild
Keyword(s):  
Research Area ◽  
Lake Constance ◽  
Content Type ◽  
Personal Mobility ◽  
Visitor Management ◽  
Activity Schedule ◽  
Customer Perspective ◽  
High Level ◽  
First Time ◽  
Practical Implications

Purpose The purpose of this paper is to examine visitor management in the German-Swiss border area of the Lake Constance region. Taking a customer perspective, it determines the requirements for an application with the ability to optimize personal mobility. Design/methodology/approach A quantitative study and a survey of focus groups were conducted to identify movement patterns of different types of visitors and their requirements concerning the development of a visitor management application. Findings Visitors want an application that provides real-time forecasts of issues such as traffic, parking and queues and, at the same time, enables them to create a personal activity schedule based on this information. Research limitations/implications Not every subsample reached a sufficient number of cases to yield representative results. Practical implications The results may lead to an optimization and management separation of mobility flows in the research area and be helpful to municipal planners, destination marketing organizations and visitors. Originality/value The German border cities of Konstanz, Radolfzell and Singen in the Lake Constance region need improved visitor management, mainly because of a high level of shopping tourism by Swiss visitors to Germany. In the Summer months, Lake Constance is also a popular destination for leisure tourists, which causes overtourism. For the first time, the results of this research presented here offer possible solutions, in particular by showing how a mobile application for visitors could defuse the situation.

A wideband, single layer reflectarray antenna with cross loop and square ring slot loaded patch elements

2019 ◽  
Vol 11 (7) ◽  
pp. 703-710 ◽  
Author(s):  
Lingasamy Veluchamy ◽  
Gulam Nabi Alsath Mohammed ◽  
T. Selvan Krishnasamy ◽  
Rajeev Jyoti
Keyword(s):  
Ground Plane ◽  
Single Layer ◽  
Unit Cell ◽  
Operating Frequency ◽  
Geometrical Parameters ◽  
Frequency Range ◽  
Operating Frequency Range ◽  
Cell Element ◽  
Phase Range ◽  
Reflectarray Antenna

AbstractThis paper presents the design and analysis of a wideband X/Ku and Ku band reflectarray antenna. The proposed unit cell of the reflectarray antenna comprises a patch loaded with two distinct slots, viz. a square ring and a cross loop, printed on a low loss substrate, which is backed by a foam-loaded ground plane. The unit cell element offers a linear and large dynamic reflection phase range, which is achieved by optimizing the shape, location, and geometrical parameters of the two slots loaded on the patch. A 324 element microstrip reflectarray antenna of size 200 × 200 mm2 is constructed and analyzed for its radiation characteristics by simulation and measurement. The reflectarray offers a 3 dB gain bandwidth of 50.75% with the operating frequency range of 10–16.8 GHz. It offers a peak gain and aperture efficiency of 25.4 dB and 40% at 12.6 GHz, respectively. The cross-polarization level is below −40 dB over the entire operating frequency range.

Transmission and reflection characteristics of normal incidence on silicon-metal-silicon interface

2020 ◽  
Vol 34 (13) ◽  
pp. 2050135
Author(s):  
Xu Sun ◽  
Pengfei Zhu ◽  
Yunxia Ping ◽  
Kun Zhu ◽  
Chaomin Zhang ◽  
...  
Keyword(s):  
Normal Incidence ◽  
Waveguide Structure ◽  
Frequency Range ◽  
Potential Applications ◽  
Broadband Pulse ◽  
Two Peaks ◽  
Silicon Interface ◽  
First Time ◽  
Reflection Characteristics ◽  
Transmission And Reflection

We investigate transmission and reflection properties of a broadband pulse with normal incidence on silicon-metal-silicon (SMS) for the first time, to the best of our knowledge. The results show that in lower frequency range, the transmission is close to zero, and the reflection and loss are in the range 0.50–0.90, 0.10 to 0.50, respectively. In higher frequency range, the transmission spectrum has two peaks, with transmittance 0.69, 0.90, and at same frequencies as the transmission peaks, the reflection spectrum has two troughs with reflectance 0.00, 0.02 and corresponding losses are 0.10, 0.29, respectively. This simple waveguide structure may have potential applications in silicon photonics, such as filters and laser oscillation cavities.

A Confrontation between Two Doctrines: The Birth of Struggle for Hegemony in Hebrew Children's Literature during the 1930s and 1940s

2008 ◽  
Vol 1 (2) ◽  
pp. 139-155 ◽  
Author(s):  
YAEL DARR
Keyword(s):  
Children's Literature ◽  
Educational System ◽  
Single Channel ◽  
Children’S Literature ◽  
The Political ◽  
Literary Creation ◽  
History Of ◽  
High Level ◽  
First Time ◽  
Literary Quality

This article describes a crucial and fundamental stage in the transformation of Hebrew children's literature, during the late 1930s and 1940s, from a single channel of expression to a multi-layered polyphony of models and voices. It claims that for the first time in the history of Hebrew children's literature there took place a doctrinal confrontation between two groups of taste-makers. The article outlines the pedagogical and ideological designs of traditionalist Zionist educators, and suggests how these were challenged by a group of prominent writers of adult poetry, members of the Modernist movement. These writers, it is argued, advocated autonomous literary creation, and insisted on a high level of literary quality. Their intervention not only dramatically changed the repertoire of Hebrew children's literature, but also the rules of literary discourse. The article suggests that, through the Modernists’ polemical efforts, Hebrew children's literature was able to free itself from its position as an apparatus controlled by the political-educational system and to become a dynamic and multi-layered field.

scholarly journals Mutations in fbiD (Rv2983) as a Novel Determinant of Resistance to Pretomanid and Delamanid in Mycobacterium tuberculosis

2020 ◽  
Vol 65 (1) ◽  
pp. e01948-20
Author(s):  
Dalin Rifat ◽  
Si-Yang Li ◽  
Thomas Ioerger ◽  
Keshav Shah ◽  
Jean-Philippe Lanoix ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Evidence ◽  
Clinical Samples ◽  
Loss Of Function ◽  
Wild Type ◽  
Content Type ◽  
Solid Media ◽  
High Level ◽  
Level Resistance

ABSTRACTThe nitroimidazole prodrugs delamanid and pretomanid comprise one of only two new antimicrobial classes approved to treat tuberculosis (TB) in 50 years. Prior in vitro studies suggest a relatively low barrier to nitroimidazole resistance in Mycobacterium tuberculosis, but clinical evidence is limited to date. We selected pretomanid-resistant M. tuberculosis mutants in two mouse models of TB using a range of pretomanid doses. The frequency of spontaneous resistance was approximately 10−5 CFU. Whole-genome sequencing of 161 resistant isolates from 47 mice revealed 99 unique mutations, of which 91% occurred in 1 of 5 genes previously associated with nitroimidazole activation and resistance, namely, fbiC (56%), fbiA (15%), ddn (12%), fgd (4%), and fbiB (4%). Nearly all mutations were unique to a single mouse and not previously identified. The remaining 9% of resistant mutants harbored mutations in Rv2983 (fbiD), a gene not previously associated with nitroimidazole resistance but recently shown to be a guanylyltransferase necessary for cofactor F420 synthesis. Most mutants exhibited high-level resistance to pretomanid and delamanid, although Rv2983 and fbiB mutants exhibited high-level pretomanid resistance but relatively small changes in delamanid susceptibility. Complementing an Rv2983 mutant with wild-type Rv2983 restored susceptibility to pretomanid and delamanid. By quantifying intracellular F420 and its precursor Fo in overexpressing and loss-of-function mutants, we provide further evidence that Rv2983 is necessary for F420 biosynthesis. Finally, Rv2983 mutants and other F420H2-deficient mutants displayed hypersusceptibility to some antibiotics and to concentrations of malachite green found in solid media used to isolate and propagate mycobacteria from clinical samples.

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