bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of corporate social responsibility on customer loyalty: A case for two global corporations in China
Authors: Lu Xiaoming , Liu Hoi Wan , Rahman Mizan
Published: May 2017

Corporate social responsibility (CSR) initiatives have differential impact on developing customer loyalty in the context of two leading international sportswear companies operating in China. Academic interest in CSR in China has grown over the years. The findings suggest a relatively strong impact of CSR dimensions (e.g., workplace, marketplace, and environment support) and other related attributes (e.g., price, product quality, and uniqueness) on developing customer loyalty in China. There are regional differences in China in relation to customers’ CSR perceptions and the likelihood of being influenced by a company’s CSR initiatives.
China’s economic growth and future prosperity
Authors: Tong Junie T. , McManus John
Published: May 2017

China has a population three times more than all other transition economies combined, and China’s economic development in the last two decades has been nothing short of phenomenal, having overtaken Japan as the world’s second‐largest economy. China’s future economic growth, social and political stability will undoubtedly have an unprecedented influence on the order and fiscal stability of the Chinese people.
Surgical considerations for papillary thyroid microcarcinomas
Authors: Boucai Laura , Bernet Victor , Shaha Ashok , Shindo Maisie L. , Stack Brendan C. , Tuttle Robert M.
Published: May 2017

We reevaluate current treatment recommendations of papillary thyroid microcarcinomas taking into account the indolent behavior of these tumors, and the potential morbidity that may result from an unnecessary surgery. The goals of this communication are to: 1) provide surgeons and endocrinologists with the most up‐to‐date evidence on management of microcarcinomas, 2) outline appropriate instances for active surveillance, and 3) describe the role of surgical interventions for microcarcinomas including lobectomy, total thyroidectomy, and central neck dissection.
Intervention for elevated intracranial pressure improves success rate after repair of spontaneous cerebrospinal fluid leaks
Authors: Teachey William , Grayson Jessica , Cho Do‐Yeon , Riley Kristen O. , Woodworth Bradford A.
Published: May 2017

Objectives/Hypothesis

Spontaneous cerebrospinal fluid (CSF) leaks are associated with increased intracranial pressure (ICP) and considered a manifestation of idiopathic intracranial hypertension. Although postoperative acetazolamide and placement of CSF shunt systems are considered valuable interventions for elevated ICP, the impact on recurrence rate remains unclear. The objective of this study was to systematically review evidence from reported literature to evaluate whether postoperative ICP management reduces recurrence rates after primary endoscopic repair.

Study Design

Prospective case series and systematic review.

Methods

Demographics, defect location, success rates, and ICP management in spontaneous CSF leak patients were prospectively collected over 8 years. A search was also conducted in PubMed to identify studies reporting cases of spontaneous CSF rhinorrhea.

Results

Fifty‐six articles with nonduplicated data were identified and combined with a prospective series of 108 patients for a total of 679 patients treated for spontaneous CSF rhinorrhea. Average age was 50.4 years with 77% female. Average body mass index was 35.8 kg/m2. Defects were most commonly located in the sphenoid sinus (n = 334) followed by the ethmoid (n = 318) and the frontal sinus (n = 46). Successful primary repair was 92.82% in patient cohorts where ICP evaluation and intervention with acetazolamide or CSF shunt systems was performed, but was significantly decreased to 81.87% in series with no active management of elevated ICP (P < .001).

Conclusions

Evaluation and intervention for elevated ICP in spontaneous CSF leaks is associated with significantly improved success rates following primary endoscopic repair.

Level of Evidence

4. Laryngoscope, 127:2011–2016, 2017
Simple Covalent Attachment of Redox‐Active Nitroxyl Radicals to Graphene via Diels‐Alder Cycloaddition
Authors: Lazar Ion‐Matei , Rostas Arpad M. , Straub Paula S. , Schleicher Erik , Weber Stefan , Mülhaupt Rolf
Published: May 2017

Here, this study reports a novel single‐step preparation of graphene functionalized by redox‐active nitroxyl radicals, a promising electrode material, without the requirement of graphite oxidation. Key feature of this concept is the Diels‐Alder [4+2] cycloaddition of dispersed graphene (DG), which has been obtained by shear‐induced solution exfoliation of graphite and functionalized maleimides as dienophiles. The redox‐active organic radical 2,2,6,6,‐tetramethylpiperdinyl‐1‐oxyl (TEMPO) is covalently attached by cycloaddition of DG with either N‐(1‐oxyl‐2,2,6,6,‐tetramethyl‐4‐piperidinyl)‐maleimide (TEMPO‐MI), or N‐(2,2,6,6‐tetramethyl‐piperidinyl)‐maleimide (TEMP‐MI), and subsequent oxidation. Successful product formation could be confirmed by high field Electron Paramagnetic Resonance (EPR) spectroscopy. Temperature‐dependent reaction monitoring by time‐resolved EPR in conjunction with Raman spectroscopy and elemental analysis results in an optimum cycloaddition temperature of 130 °C, at which 2.2 wt% TEMPO‐MI has been incorporated. However, owing to the limited thermal stability of TEMPO‐MI at temperatures above 100 °C, as again verified by EPR spectroscopy, the route via TEMP‐MI and subsequent oxidation is favored. Cyclovoltammetric evaluation of TEMPO‐functionalized graphene shows a reversible redox potential of +0.65 V as measured against Ag/AgCl, similar to that of TEMPO in solution. Hence, organic radical functionalized graphene derived by cycloaddition shows great potential for an easy production of electrodes that aim toward applications in organic energy storage devices.

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Clinical and molecular characterization of cystinuria in a French cohort: relevance of assessing large‐scale rearrangements and splicing variants
Authors: Gaildrat Pascaline , Lebbah Said , Tebani Abdellah , Sudrié‐Arnaud Bénédicte , Tostivint Isabelle , Bollee Guillaume , Tubeuf Hélène , Charles Thomas , Bertholet‐Thomas Aurelia , Goldenberg Alice , Barbey Frederic , Martins Alexandra , Saugier‐Veber Pascale , Frébourg Thierry , Knebelmann Bertrand , Bekri Soumeya
Published: May 2017

Background

Cystinuria is an autosomal recessive disorder of dibasic amino acid transport in the kidney and the intestine leading to increased urinary cystine excretion and nephrolithiasis. Two genes, SLC3A1 and SLC7A9, coding respectively for rBAT and b0,+AT, account for the genetic basis of cystinuria.

Methods

This study reports the clinical and molecular characterization of a French cohort including 112 cystinuria patients and 25 relatives from 99 families. Molecular screening was performed using sequencing and Quantitative Multiplex PCR of Short Fluorescent Fragments analyses. Functional minigene‐based assays have been used to characterize splicing variants.

Results

Eighty‐eight pathogenic nucleotide changes were identified in SLC3A1 (63) and SLC7A9 (25) genes, of which 42 were novel. Interestingly, 17% (15/88) and 11% (10/88) of the total number of variants correspond, respectively, to large‐scale rearrangements and splicing mutations. Functional minigene‐based assays were performed for six variants located outside the most conserved sequences of the splice sites; three variants affect splice sites, while three others modify exonic splicing regulatory elements (ESR), in good agreement with a new in silico prediction based on ΔtESRseq values.

Conclusion

This report expands the spectrum of SLC3A1 and SLC7A9 variants and supports that digenic inheritance is unlikely. Furthermore, it highlights the relevance of assessing large‐scale rearrangements and splicing mutations to fully characterize cystinuria patients at the molecular level.
Finding Relevant Parameters for the Thin‐film Photovoltaic Cells Production Process with the Application of Data Mining Methods
Authors: Ulaczyk Jan , Morawiec Krzysztof , Zabierowski Paweł , Drobiazg Tomasz , Barreau Nicolas
Published: May 2017

A data mining approach is proposed as a useful tool for the control parameters analysis of the 3‐stage CIGSe photovoltaic cell production process, in order to find variables that are the most relevant for cell electric parameters and efficiency. The analysed data set consists of stage duration times, heater power values as well as temperatures for the element sources and the substrate – there are 14 variables per sample in total. The most relevant variables of the process have been found based on the so‐called random forest analysis with the application of the Boruta algorithm. 118 CIGSe samples, prepared at Institut des Matériaux Jean Rouxel, were analysed. The results are close to experimental knowledge on the CIGSe cells production process. They bring new evidence to production parameters of new cells and further research.
Laplace transform: a new approach in solving linear quaternion differential equations
Authors: Cai Zhen‐Feng , Kou Kit Ian
Published: May 2017

The theory of real quaternion differential equations has recently received more attention, but significant challenges remain the non‐commutativity structure. They have numerous applications throughout engineering and physics. In the present investigation, the Laplace transform approach to solve the linear quaternion differential equations is achieved. Specifically, the process of solving a quaternion different equation is transformed to an algebraic quaternion problem. The Laplace transform makes solving linear ODEs and the related initial value problems much easier. It has two major advantages over the methods discussed in literature. The corresponding initial value problems can be solved without first determining a general solution. More importantly, a particularly powerful feature of this method is the use of the Heaviside functions. It is helpful in solving problems, which is represented by complicated quaternion periodic functions. Copyright © 2017 John Wiley & Sons, Ltd.
Gyroscopic signal smoothness assessment by geometric jolt estimation
Authors: Fiori Simone
Published: May 2017

The present contribution focuses on the estimation of the geometric acceleration and of the geometric jolt (namely, the derivative of the acceleration) of a multidimensional, structured gyroscopic signal. A gyroscopic signal encodes the instantaneous orientation of a rigid body during a full three‐dimensional rotation that is regarded as a trajectory in the curved space SO(3) of the special orthogonal matrices. The geometric acceleration and jolt associated to a gyroscopic signal are evaluated through the rules of calculus prescribed by differential geometry. Such an endeavor is motivated by recent studies on the smoothness of human body movement in biomechanical engineering, sports science, and rehabilitation neuroengineering. Two indexes of smoothness are compared, namely, a normalized proper geometric acceleration index and a normalized proper geometric jolt index. Our investigation concludes that, in the considered experiments with measured signals, for relatively low values of the acceleration and of the jolt indexes, such indexes are strongly positively correlated. Copyright © 2017 John Wiley & Sons, Ltd.
Microstrip Rotman lens design controlled by taper aperture
Authors: Ferreira Filho Ilidio L. , Mosso Marbey M.
Published: May 2017

This article presents a methodology for the design of a more reliable printed microstrip Rotman lens based on the taper aperture that excites the lens and with the support of electromagnetic simulation software. Prototypes are developed on dielectric substrates (ɛr = 10.2) for phased array applications in frequencies of defense systems and radar (4–6 GHz) and of future 5G mobile systems (27–29 GHz). Return loss, isolation, and radiation pattern are simulated and measured showing the good performance of this methodology.
A broadband half mode substrate integrated waveguide balun using composite right/left‐handed transmission line
Authors: Eom Dong‐Sik , Lee Hai‐Young
Published: May 2017

A broadband half mode substrate integrated waveguide (HMSIW) balun using composite right/left‐handed transmission line is proposed. The proposed structure is consisted of a broadband microstrip Wilkinson power divider and two phase adjusted‐HMSIWs, new CRLH‐HMSIW and HMSIW thru. The broadband microstrip Wilkinson power divider is bridged with the HMSIW in/outputs. The new CRLH‐HMSIW is designed with surface mounted capacitors and printed circuit board (PCB) embedded inductors on the open edge of the HMSIW. The measured prototype shows a 1 dB amplitude imbalance and 180° ± 5° phase difference in a frequency band of 8–13.3 GHz, which has 50% fractional bandwidth. The simulation shows a good agreement with the measurement.
Reliable assessment of topological modifications in UWB antennas by means of multi‐objective optimization
Authors: Bekasiewicz Adrian , Koziel Slawomir
Published: May 2017

In this letter, the problem of systematic and rigorous assessment of effects of topological modifications on the performance of miniaturized UWB antennas has been addressed. The primary assessment tool is fast multi‐objective optimization, here, realized using a recent sequential domain patching algorithm. Identification of the Pareto front for an antenna structure, ie, the set of designs representing the best possible tradeoffs between conflicting objectives (here, reflection characteristic and the antenna footprint) allows for conclusive comparison of antenna performance and suitability for space‐limited applications. Here, we are interested in the effect of seemingly small topological modifications, the importance of which cannot be detected using parameters sweeps because of heavy interactions between such modifications and the remaining parameters of the structure. An UWB monopole case study demonstrates that small topological amendments may lead to considerable improvement of antenna performance and reduction of its size. Numerical results are supported by experimental validation of the fabricated antenna prototypes.
Design of a wideband loaded tapered slot antenna with broad beamwidth and enhanced front‐to‐back ratio
Authors: Chang Yu Lin , Cui Chao‐Yi , Zhang Li , Jiao Yong‐Chang
Published: May 2017

A loaded wideband tapered slot antenna (TSA) with broad beamwidth and enhanced front‐to‐back ratio (FBR) is proposed. The antenna is obtained by adding a series of loading structures to a traditional microstrip‐fed linearly TSA (LTSA). The performance of the antenna with different loading structures has been discussed. Finally, the antenna is manufactured and measured. The measured results show good performance of impendence bandwidth is approximately 82.2% (4.3–10.3 GHz) for VSWR ≤ 2, while a pattern bandwidth of 50.4% (4.3–7.2 GHz) for more than 100° 3‐dB beamwidth (HPBW) both in E‐plane and H‐plane is obtained. Moreover, a new method for FBR improvement is presented and a moderately high average FBR (AFBR) about 19 dB is obtained in the pattern band. The simulated results agree with the measured results. All above indicates that the proposed antenna cannot only be used in wireless communication, but also as antenna unit of wide‐scan phased array antennas (WSPAAs).
High performance terahertz slotted waveguide antenna based on electrically split ring resonator metasurface employing low epsilon medium for E‐plane beam focusing
Authors: Abdelrehim Adel A. A. , Ghafouri‐Shiraz Hooshang
Published: May 2017

In this article, a high performance terahertz slotted waveguide antenna incorporated with three dimension anisotropic low epsilon medium (LEM) is proposed, designed and theoretically investigated. The LEM is constructed from multilayer two dimension structure of electrically split ring resonator (eSRR) metasurface which exhibits anisotropic LEM medium in direction of propagation when it is placed in front of the slotted waveguide antenna at optimum distance. As a result, the E‐plane radiation beam of the slotted waveguide antenna is focused, and hence the directivity and the gain are improved, while the beam area is reduced. The proposed antenna as well as the LEM structure operating at 303 GHz are designed, optimized, and numerically simulated by using CST software. The effective parameters of the eSRR structure are extracted by Nicolson Ross Weir algorithm from the S‐parameters. The simulated results showed that, the E‐plane gain of the proposed slotted waveguide antenna is improved from 6.7 to 10.1 dB compared with the conventional slotted waveguide antenna. In addition, the E‐plane beam width is reduced from 94.1° to about 47°. The antenna return loss and the bandwidth are slightly changed. Furthermore, the proposed THz antenna offered easier fabrication processes with a high gain if it is compared with the horn antenna of the same size.
Wide‐band varactorless dual‐resonance divide‐by‐4 injection‐locked frequency divider
Authors: Jang Sheng‐Lyang , Hung Chih‐Ting , Huang Yi‐Ru , Lai Wen‐Cheng , Juang Miin‐Horng
Published: May 2017

A varactorless divide‐by‐4 injection‐locked frequency divider (ILFD) with LC resonator is designed. The ILFD uses the parasitic capacitors and the inductor architecture to construct a dual‐resonance resonator. The ILFD has two locking ranges associated with the dual‐resonance resonator. The locking range of the ÷4 ILFD is wider than conventional single‐band ÷4 LC‐tank ILFD because of overlapped locking ranges. The designed single‐stage ÷4 ILFD was fabricated in the TSMC 0.18 μm 1P6M CMOS process. At the incident power of 0 dBm, the locking range is 6.6 GHz from 7.3 to 13.9 GHz at the power consumption of 5.59 mW.
A new Laguerre‐based discontinuous Galerkin time‐domain method
Authors: Shi Yan , Tian Cheng‐Yi , Liu Zhi‐Qi , Liang Chang‐Hong
Published: May 2017

In this article, a Laguerre‐based discontinuous Galerkin time‐domain (DGTD) method using a new temporal basis function has been developed to solve transient electromagnetic problems. The new temporal basis function is a linear combination of weighted Laguerre polynomials, and can be easily implemented by adding some extra terms in the conventional Laguerre‐based DGTD method. With the proposed temporal basis function, initial condition of a general electromagnetic problem can be implicitly satisfied, and thus the resultant computational accuracy can be improved. Numerical results including a parallel‐plate waveguide, a dual‐mode circular waveguide filter, and a conducting ship demonstrate good performance of the proposed method.
Miniaturized antipodal tapered slot antenna with lower frequency band extension characteristic
Authors: Hong H. , Jeong J. G. , Ahn J. , Yoon I.‐J. , Yoon Y. J.
Published: May 2017

An antipodal tapered slot antenna (ATSA) is miniaturized by extending the lower operating frequency range using spidron‐shaped slots and additional impedance‐matching stubs at the tapered radiator. Simulation and measurement results show that the electrical size of the antenna, or the lowest matching frequency, is reduced by 56.4% when compared to a conventional ATSA with the same physical dimensions. The realized gain is also improved in the newly matched low‐end operating frequency.
Dual‐band circularly polarized modified circular aperture loaded cylindrical dielectric resonator antenna for wireless applications
Authors: Sharma Anand , Das Gourab , Gangwar Ravi Kumar
Published: May 2017

This communication inspects a dual‐band circularly polarized cylindrical dielectric resonator antenna (CDRA). CDRA is excited by using modified circular shaped aperture. Three attractive features of proposed radiator are as follow: (i) circular shaped aperture creates triple hybrid radiating modes in CDRA (i.e., HEM11δ, HEM12δ‐like and HEM12δ) which radiates in broadside direction; (ii) modified circular shaped aperture generates CP wave in both the frequency bands; (iii) LHCP/RHCP radiation of proposed radiator can be controlled by taking mirror image of modified circular aperture. Archetype of proposed radiator has been fabricated and tested in order to validate the simulated results. Good settlement is found between experimental and simulated outcomes. The experimental results display that the proposed radiator has usable fractional bandwidth of 18.04% (2.42–2.90 GHz) and 19.85% (4.9–5.98 GHz). 3‐dB axial ratio bandwidth (ARBW) of proposed radiator is about 6.45% (2.55–2.72 GHz) and 14.74% (4.9–5.68 GHz) in lower and upper frequency band respectively. The proposed radiator is fairly applicable for WLAN (2.4/5.2/5.8 GHz) and WiMAX (2.5/5.5 GHz) applications.
The striped rectangular patch antenna
Authors: Wang Yiying , Lu Yinghua
Published: May 2017

In this article, both the patch and the ground plane of the conventional rectangular patch antenna are sliced into 5 strips along its E‐plane, respectively. The strip widths of the sliced patch are the same, and the gaps between the neighboring strips are uniform. Considering the solder and the current distribution on the ground, the inner 3 strips of the sliced ground are kept the same widths and just change the widths of the outer strips and the gaps, and these gaps are the same as well in the designs. Then, the conventional and one‐sliced antenna prototypes are fabricated to be compared. They are excited by the coaxial probes and the substrates are Wangling F4BM220, where the height is 1.50 mm, the permittivity is 2.20, and its tangent loss is 0.001. The dimension of the substrate is 40 × 40 mm. The measured results agree well with those of the simulations. Both the impedance and realized gain bandwidths of the sliced antenna are wider than those of the conventional ones. However, the realized gain reduces after being sliced. Finally, the parametric study on different gaps of the ground plane is also investigated.
Investigations on the rectangular waveguide to SIW transition for terahertz applications
Authors: Cheng Hao Zhang , Wang Jia
Published: May 2017

In this paper, the performance of a terahertz rectangular waveguide to substrate integrated waveguide (SIW) transition using fin line coupling structure is investigated. Two prototypes working at 140 GHz and 180 GHz frequency bands are both designed, and fabricated by using the low‐cost printed‐circuit‐board (PCB) technology. Full‐wave simulations have been used to synthesize and optimize the transitions. In order to evaluate effectively the insertion loss of the transition, three different lengths of transitions are designed and measured for D‐band and G‐band, respectively. Measurement results show that from 110 GHz to 150 GHz and from 169 GHz to 193 GHz, the average insertion loss of the terahertz transition is around 0.54 dB and 0.89 dB, respectively. And their measured return losses are both larger than 10 dB. This work demonstrates that the investigated SIW to WR6/WR5 waveguide transitions can be used for developing future planar terahertz components by using the low cost PCB process.
Metamaterial‐inspired printed UWB antenna for short range RADAR applications
Authors: Boopathi Rani R. , Pandey S. K.
Published: May 2017

This research article presents a novel design of printed antenna for 24 GHz ultra‐wideband (UWB) applications. This research develops an antenna having dimension of 5 × 6 × 0.8 mm3 which operates from 24 to 30 GHz. This is achieved using techniques such as truncation of patch edges and inclusion of complementary split ring resonator metamaterial (MTM). This antenna can be used for short range RADAR application at 24 GHz UWB for automotive appliances. This article includes the detailed investigations such as surface current distribution on antenna, far field patterns, gain, group delay and radiation efficiency over frequency, as well as measurement details. Simulation and measurement data on return loss have shown good equality which proves the feasibility of the proposed antenna.
Empirical study of stirring conditions on emulating rayleigh fading channels in a reverberation chamber
Authors: Nguyen Tien Manh , Kwon Jong Hwa , Chung Jae‐Young
Published: May 2017

An empirical study was performed to understand the relationship of stirring conditions on emulating Rayleigh fading channel inside of a reverberation chamber. The latter has dimensions of 1.8 m × 2.4 m × 1.6 m and equipped with 3 stirrers for rapid over‐the‐air testing of mobile communication devices. The stirrers were selectively turned on and off, and then the generated Rayleigh fading channel was compared with the ideal one by calculating the mean‐squared error. The results indicate that the Rayleigh fading channel inside the chamber is mostly affected by the stirrer close to the transmitting antenna. It was also demonstrated that turning on all the 3 stirrers further reduces the build‐up time of a Rayleigh fading channel, resulting in faster over‐the‐air testing capability.
Wideband slotted substrate integrated waveguide cavity‐backed antenna for Ku – band application
Authors: Kumar Arvind , Raghavan Singaravelu
Published: May 2017

In this article, a wideband substrate integrated waveguide (SIW) cavity‐backed antenna with multi‐resonance slots for
band application is presented and experimentally investigated in terms of antenna performances including S‐parameter, optimized parameter values, gain, and radiation pattern. With the proper placement of multi‐resonant slots on the backside of the cavity, the hybrid modes are generate in the frequency band of interest. These modes can be tuned by varying the slot parameters which result the merging of different resonant frequencies, therefore the simulated impedance bandwidth is substantially enhanced to 1.46 GHz, ranging from 12.7 to 14.16 GHz with a gain of 6.0 to 8.0 dBi. The measured result showing the fractional bandwidth of the proposed antenna is 11.8% and 11% achieved at the resonant frequencies of 13 and 14 GHz, respectively. Moreover, the antenna has the features of simple‐single layer structure, resonant frequency flexibility with multi‐resonance characteristics over a wide impedance bandwidth.
Multi‐section branch‐line couplers for crossover application
Authors: Yeo S. P. , Deng N.
Published: May 2017

Other researchers have already designed 1‐, 2‐, 3‐, and 4‐section versions of the branch‐line coupler for crossover application. The focus of this article is on the 5‐, 6‐, and 7‐section versions. Laboratory tests show that the resulting crossovers have bandwidths of 49%, 54%, and 59% respectively.
Wideband bandstop filter using spurline and symmetric coupled open stubs
Authors: Lee Hyun‐Seung , Lim Jeong‐Taek , Jung Bang‐Chul , Woo Jong‐Myung , Kim Choul‐Young
Published: May 2017

In this article, we propose a structure that can extend the stopband of the bandstop filter (BSF). The bandwidth of the BSF can be extended by symmetrically combining the BSFs that electrically couple the ends of two open stubs located in parallel on a single microstrip transmission line containing a spurline. The bandwidth of the stopband of the BSF proposed in this article is increased to 3.5 GHz. We confirm that when compared to parallel open stubs without spurline filters, the stopband bandwidth is extended by approximately 289% (rejection depth: −20 dB).
Design of a novel compact microstrip diplexer with low insertion loss
Authors: Rezaei A. , Noori L. , Mohammadi H.
Published: May 2017

In this article, a microstrip diplexer is implemented based on a novel combination of the coupled lines and spiral structures in order to reduce the circuit size as well as insertion losses. This diplexer with an elliptic function frequency response operates at 2.4/2.79 GHz for wireless applications. Several transmission zeros on the both sides of two passbands are realized, which improve the selectivity. A theory method is presented that helps to miniaturization, control the resonance frequency, improve the insertion loss, and external quality factor simultaneously. The proposed diplexer has a compact size of 0.3λg × 0.25λg with low insertion losses of 0.18/0.39 dB at 2.4/2.79 GHz. The isolation between the two channels (S23) is better than 20.5 dB from DC up to 6 GHz. The designed diplexer is fabricated and measured. There is a good agreement between the simulated and measured results.
A wideband common‐gate CMOSLNA employing complementary MGTR technique
Authors: Guo Benqing , Chen Jun
Published: May 2017

A wideband capacitor cross‐coupled common‐gate low‐noise amplifier (CGLNA) featured with high gain, low noise, and enhanced linearity is proposed. The linearity is enhanced by complementary multi‐gated transistor (CMGTR) technique. The bulk voltage and scaling size of auxiliary transistors are tuned to shift the distortion coefficients, compensating the nonlinearity of main transistors. In addition, the current reuse by stacked PMOS/NMOS configuration reduces power consumption while guaranteeing the input matching. A prototype is implemented in a 0.18 μm RF CMOS process. The measurement shows a maximal voltage gain of 19.5 dB, an average noise figure (NF) of 2.1 dB, and an input‐referred third‐order intercept point (IIP3) of 8.3–10 dBm over a 3 dB bandwidth of 0.2–1.6 GHz, respectively. It consumes only 3.5 mA from a 2.2 V supply.
Dual‐band balun with high isolation and flexible implementation based on three‐section pi‐shaped coupled lines
Authors: Yao Lidan , Wu Yongle , Liu Yuanan
Published: May 2017

A novel planar dual‐band balun with high isolation and flexible implementation is proposed in this letter. Based on the design of a single‐band branch‐line balun, the ideal all‐port matching and output isolation are fulfilled. To achieve the dual‐band operation, innovative structures consisting of three‐section Pi‐shaped coupled lines in place of conventional branch lines with arbitrary impedances and phases are exploited. Moreover, expedient implementations can be regulated according to practical requirements while maintaining identical performance. Analytical closed‐form equations are obtained by even‐odd mode method and ABCD matrix. Analyses concerning the available frequency ratio are provided as well. For verification, a prototype working at 1.74 and 4.91 GHz is designed and fabricated. Both the simulation and measurement exhibit excellent properties and agree well with each other.
Spectroscopy of a Nd:YVO4 diode pumped solid state laser
Authors: Öztürk Oğuzhan Mete , Bayer Mustafa Mert , Anwar Muhammad Sohail , Zakwan Muhammad , Serpengüzel Ali
Published: May 2017

The 1 064 nm lasing, and 1 074 nm, and 1  084 nm luminescence are observed in a Nd:YVO4 DPSSL along with their corresponding SHG. Fundamental transitions are analyzed in terms of Stark effect. The relative intensity of the 1 064 nm laser line is an order of magnitude bigger than the luminescence lines.
SRR loaded CPW‐fed multiple band rose flower‐shaped fractal antenna
Authors: Elavarasi C. , Shanmuganantham T.
Published: May 2017

In this article, a compact coplanar waveguide (CPW) faded rose flower shaped fractal antenna is presented. The proposed design consists of a rose patch (top) and a split ring resonator loaded beneath the FR4, which are accountable for achieving multiple band characteristics, smallness, and fine impedance matching. The SRR rose antenna with a compacted dimension of 12 × 12 × 1.6 mm3 is fabricated and tested. The testing results show that the design proposed, having −10 dB for 1.031, 4.591, 8.284, 13.41, and 17.17 GHz, respectively, covers WLAN/IEEE 802.16/Wi‐MAX/ITU bands. It has fine radiation characteristics for both E field and H field in all the preferred operational bands and generates superior performances compared to the existing designed antenna in the reviews. The loaded rose fractal SRR structure recital is validated through negative permeability extraction and different parametric studies.
A designing method for band‐reject filter with high selectivity and tunable bandwidth
Authors: Liu Yu , Mu Chong , Xu Fang , Wang Zongjie , Li Yuenan
Published: May 2017

High selectivity band‐reject filters are usually demanded in applications such as removing QAM signals of digital cable TV network and removing interference signals in communication systems. In this letter, a filter design method which employ discontinuous meandered transmission line and isolated board is proposed. The experimental results show that the transient bandwidth (between −3 and −20 dB) of our filters is less than 1 MHz. Besides, the rejecting bandwidth of our filters can be tuned to fulfill the requirements of different applications.
Electron driven mobility model by light on the stacked metal–dielectric interfaces
Authors: Pornsuwancharoen N. , Youplao Pichai , Amiri I.S. , Ali Jalil , Yupapin Preecha
Published: May 2017

An electron mobility enhancement is the very important phenomenon of an electron in the electronic device, where the high electronic device performance has the good electron mobility, which is obtained by the overall electron drift velocity in the electronic material driven potential difference. The increase in electron mobility by the injected high group velocity pulse is proposed in this article. By using light pulse input into the nonlinear microring resonator, light pulse group velocity can be tuned and increased, from which the required output group velocity can be obtained, which can be used to drive electron within the plasmonic waveguide, where eventually, the relative electron mobility can be obtained, the increasing in the electron mobility after adding up by the driven optical fields can be connected to the external electronic devices and circuits, which can be useful for many applications.
Investigation of a notched UWB antenna with opening and shorting resonators
Authors: Gao Guoping , Hu Bin , Yang Chen , Wang Shaofei
Published: May 2017

In this article, a planar ring monopole UWB antenna with two kinds of resonators are presented and investigated. The half wavelength opening resonator and quarter wavelength shorting resonator are coupled with the feed line capacitive to obtain notched characteristic. The contrast of current distribution demonstrates this novel method, and experimental results show that the proposed antennas meet the requirement of ultra‐wide bandwidth (3.1–10.6 GHz), while avoiding the interference from WLAN band. Some important models and parameters, such as the transmission line model, equivalent circuit model, VSWR, radiation pattern antenna gain, and transfer function are also studied to evaluate notched characteristics.
A compact sixteenth‐mode substrate integrated waveguide bandpass filter with improved out‐of‐band performance
Authors: Azad Amit Ranjan , Mohan Akhilesh
Published: May 2017

This article presents a compact sixteenth‐mode substrate integrated waveguide (SMSIW) bandpass filter operating at fundamental mode TM01. The filter size is reduced by introducing SMSIW circular cavity. It occupies only 6.25% of the conventional substrate integrated waveguide (SIW) circular cavity with same resonant frequency. The higher‐order mode TM02 of the circular cavity is suppressed by etching two slots on the ground plane to improve out‐of‐band performance. Measured results show that an out‐of‐band rejection better than 18 dB is obtained from 2.5 GHz to 8 GHz. The in‐band and out‐of‐band performance obtained from simulation and measurement are presented and they are in good agreement. The filter exhibits good stopband performance and compact size.
Design of a C‐band miniaturized rectifying circuit with a multilayer structure
Authors: Feng Xiaoping , Huang Kama , Liu Yilin
Published: May 2017

This article proposes a novel concept for constructing a microwave (MW) rectifying circuit by using a multilayer structure, aiming at reducing physical dimensions. Specifically, an embedded via‐hole with connection of conductor layers in the multilayer structure is designed. A full‐wave electromagnetic analysis is carried out to study the impacts of various via‐hole design parameters. Then, a C‐band rectifying circuit based on HSMS‐286C Schottky diode is fabricated with the proposed multilayer structure for demonstration. The maximum MW‐DC conversion efficiency of 61% has been measured. In comparison with the counterpart, namely a conventional microstrip rectifying circuit, the proposed multilayer circuit shows a great reduction of physical dimensions and a very similar efficiency, which validates that the proposed circuit can reduce physical dimensions significantly without sacrificing the MW‐DC conversion efficiency.
Compact power divider with improved isolation and bandpass response
Authors: He Zhaosheng , Jiang You Chang , Leng Supeng , Li Xiang
Published: May 2017

This article presents a compact power divider with band‐pass response and improved isolation by using substrate integrated waveguide (SIW) and defected ground structure (DGS) techniques. The band‐pass response is realized by combining the high‐pass characteristic of SIW and low‐pass feature of DGS. In order to achieve improved isolation performance, a slot which is terminated by four resistors is etched on the top plane of the SIW to balance the three input/output ports. The size of the proposed power divider is relatively small because of the slow‐wave characteristic of DGS. To verify the proposed concept, a prototype power divider with equal power division is fabricated and measured. Measured results show that it has a 3‐dB pass‐band from 8 GHz to 10 GHz and the isolation is higher than 20 dB within the pass‐band.
A novel dual polarized waveguide fed circular patch antenna for Ku band applications
Authors: Kumar P. , Masa‐Campos José Luis
Published: May 2017

This article presents the design of a novel dual polarized waveguide fed circular microstrip patch antenna for Ku band applications. The circular microstrip patch is fed by using a square waveguide and a cross slot. The cross slot consists two orthogonal slots for coupling the energy associated with two orthogonal modes propagated in the square waveguide, i.e. TE10 and TE01 mode in order to achieve dual polarization. The orthomode transducer is designed for the frequency range of interest in order to separate and combine two orthogonal modes and to connect with two standard WR‐51 rectangular waveguides. The design is optimized using the electromagnetic software CST Microwave Studio and the structure with optimized dimensions is fabricated and measured. The measured along with simulated antenna parameters are presented. The designed and developed dual polarized waveguide fed circular patch antenna can be used for Ku band applications.
Transmission characteristics of a two dimensional antiscatter grid prototype for CBCT
Authors: Altunbas Cem , Kavanagh Brian , Alexeev Timur , Miften Moyed
Published: May 2017

Aim

High fraction of scattered radiation in cone‐beam CT (CBCT) imaging degrades CT number accuracy and visualization of low contrast objects. To suppress scatter in CBCT projections, we developed a focused, two‐dimensional antiscatter grid (2DASG) prototype. In this work, we report on the primary and scatter transmission characteristics of the 2DASG prototype aimed for linac mounted, offset detector geometry CBCT systems in radiation therapy, and compared its performance to a conventional one‐dimensional ASG (1DASG).

Methods

The 2DASG is an array of through‐holes separated by 0.1 mm septa that was fabricated from tungsten using additive manufacturing techniques. Through‐holes’ focusing geometry was designed for offset detector CBCT in Varian TrueBeam system. Two types of ASGs were evaluated: (a) a conventional 1DASG with a grid ratio of 10, (b) the 2DASG prototype with a grid ratio of 8.2. To assess the scatter suppression performance of both ASGs, Scatter‐to‐primary ratio (SPR) and scatter transmission fraction (Ts) were measured using the beam stop method. Scatter and primary intensities were modulated by varying the phantom thickness between 10 and 40 cm. Additionally, the effect of air gap and bow tie (BT) filter on SPR and Ts were evaluated. Average primary transmission fraction (TP) and pixel specific primary transmission were also measured for both ASGs. To assess the effect of transmission characteristics on projection image signal‐to‐noise ratio (SNR), SNR improvement factor was calculated. Improvement in contrast to noise ratio (CNR) was demonstrated using a low contrast object.

Results

In comparison to 1DASG, 2DASG reduced SPRs by a factor of 3 to 6 across the range of phantom setups investigated. Ts values for 1D and 2DASGs were in the range of 21 to 29%, and 5 to 14% respectively. 2DASG continued to provide lower SPR and Ts at increased air gap and with BT filter. Tp of 1D and 2DASGs were 70.6% and 84.7% respectively. Due to the septal shadow of the 2DASG, its pixel specific primary transmission values varied between 32.5% and 99.1%. With respect to 1DASG, 2DASG provided up to factor of 1.7 more improvement in SNR across the SPR range investigated. Moreover, 2DASG provided improved visualization of low contrast objects with respect to 1DASG and NOASG setups.

Conclusions

When compared to a conventional 1DASG, 2DASG prototype provided noticeably lower SPR and Ts values, indicating its superior scatter suppression performance. 2DASG also provided 19% higher average primary transmission that was attributed to the absence of interseptal spacers and optimized grid geometry. Our results indicate that the combined effect of lower scatter and higher primary transmission provided by 2DASG may potentially translate into more accurate CT numbers and improved contrast resolution in CBCT images.
Technical Note: System for evaluating local hypothermia as a radioprotector of the rectum in a small animal model
Authors: Hrycushko Brian A. , Bing Chenchen , Futch Cecil , Wodzak Michelle , Stojadinovic Strahinja , Medin Paul M. , Chopra Rajiv
Published: May 2017

Purpose

The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single‐fraction doses common to stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) treatments. This work describes the development of a system to evaluate local hypothermia for a radioprotective effect of the rat rectum during a large dose of radiation relevant to prostate SBRT. This includes the evaluation of a 3D‐printed small animal rectal cooling device and the integration with a small animal irradiator.

Methods

A 3‐cm long, dual‐lumen rectal temperature control apparatus (RTCA) was designed in SOLIDWORKS CAD for 3D printing. The RTCA was capable of recirculating flow in a device small enough for insertion into the rat rectum, with a metal support rod for strength as well as visibility during radiation treatment planning. The outer walls of the RTCA comprised of thin heat shrink plastic, achieving efficient heat transfer into adjacent tissues. Following leak‐proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within the rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. Integration with an image‐guided small animal irradiator and associated treatment planning system included evaluation for imaging artifacts and effect of brass tubing on dose calculation.

Results

The rectal temperature adjacent to the cooling device decreased from body temperature to 15°C within 10–20 min from device insertion and was maintained at 15 ± 3°C during active cooling for the evaluated time of one hour. MR thermometry revealed a steep temperature gradient with increasing distance from the cooling device with the desired temperature range maintained within the surrounding few millimeters.

Conclusions

A 3D‐printed rectal cooling device was fabricated for the purpose of inducing local hypothermia in the rat rectum. The RTCA was simply integrated with an image‐guided small animal irradiator and Monte Carlo‐based treatment planning system to facilitate an in vivo investigation of the radioprotective effect of hypothermia for late rectal toxicity following a single large dose of radiation.
Error modeling for surrogates of dynamical systems using machine learning
Authors: Trehan Sumeet , Carlberg Kevin T. , Durlofsky Louis J.
Published: May 2017

A machine learning–based framework for modeling the error introduced by surrogate models of parameterized dynamical systems is proposed. The framework entails the use of high‐dimensional regression techniques (eg, random forests, and LASSO) to map a large set of inexpensively computed “error indicators” (ie, features) produced by the surrogate model at a given time instance to a prediction of the surrogate‐model error in a quantity of interest (QoI). This eliminates the need for the user to hand‐select a small number of informative features. The methodology requires a training set of parameter instances at which the time‐dependent surrogate‐model error is computed by simulating both the high‐fidelity and surrogate models. Using these training data, the method first determines regression‐model locality (via classification or clustering) and subsequently constructs a “local” regression model to predict the time‐instantaneous error within each identified region of feature space. We consider 2 uses for the resulting error model: (1) as a correction to the surrogate‐model QoI prediction at each time instance and (2) as a way to statistically model arbitrary functions of the time‐dependent surrogate‐model error (eg, time‐integrated errors). We apply the proposed framework to model errors in reduced‐order models of nonlinear oil‐water subsurface flow simulations, with time‐varying well‐control (bottom‐hole pressure) parameters. The reduced‐order models used in this work entail application of trajectory piecewise linearization in conjunction with proper orthogonal decomposition. When the first use of the method is considered, numerical experiments demonstrate consistent improvement in accuracy in the time‐instantaneous QoI prediction relative to the original surrogate model, across a large number of test cases. When the second use is considered, results show that the proposed method provides accurate statistical predictions of the time‐ and well‐averaged errors.
A qualitative study of women's experiences of living with COPD
Authors: Steindal Simen A. , Österlind Jane , Halvorsen Kristin , Schjelderup Therese , Kive Ellen , Sørbye Liv Wergeland , Dihle Alfhild
Published: May 2017

Aim

To explore women's experiences of living with chronic obstructive pulmonary disease (COPD) at home.

Design

An explorative and descriptive qualitative design.

Methods

A consecutive sample of nine women with COPD living at home. Data were collected in 2014 using semi‐structured interviews and analysed using a qualitative content analysis.

Results

Three main themes were identified: having a good life with COPD despite limitations; predictability and confidence in getting help; and the struggle to achieve a balance between insight and compliance with management of COPD. These women experienced limitations related to the traditional female role and felt unable to fulfil their own expectations. They experienced a good life despite limitations arising from adaptation and coping strategies. To feel safe, they needed to feel confident that they would receive the necessary help in case of exacerbation of their disease. To enhance compliance with COPD management, the women wanted education that provided specific suggestions.
Polymeric nanocarriers for cancer theranostics
Authors: Vijayan Vineeth M. , Muthu Jayabalalan
Published: May 2017

Theranostics is an emerging area in nanomedicine where therapeutic and diagnostic platforms are integrated together to perform multiple functions such as disease diagnostic and therapy, noninvasive method to determine the targeted delivery of drugs, and evaluation of drug efficacy. This review gives an overview of the different therapeutic and diagnostic strategies used to construct a theranostic system. The importance of polymer‐based theranostic carriers is presented. The different types of polymeric carriers such as micelles, liposomes, dendrimers, and nanogels explored for theranostic applications are also presented. Copyright © 2017 John Wiley & Sons, Ltd.