bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of thermophilic anaerobic digesters using inoculum mixes with enhanced methanogenic diversity
Authors: Ghanimeh Sophia , El‐Fadel Mutasem , Saikaly Pascal E 
Published: May 2017

AbstractBACKGROUNDVarious mixes of seeds have been quasi‐randomly selected to startup anaerobic digesters. In contrast, this study examines the impact of inoculating thermophilic anaerobic digesters with a designed mix of non‐acclimated seeds based on their methanogen composition, using quantitative polymerase chain reaction (QPCR) of 16S rRNA gene, to achieve high abundance and diversity of methanogens.RESULTSBased on QPCR results, two seed mixes were selected to inoculate two anaerobic digesters: digester (A) was inoculated with a control seed consisting of digestate, manure, and activated sludge; and digester (B) was inoculated with a further methanogen‐enriched seed consisting of the control seed with added compost and leachate. Both seed combinations yielded a balanced microflora that is able to achieve a successful startup. However, upon reaching steady state, digester B exhibited lower propionate levels, resulting in lower volatile fatty acids (VFAs) concentration and increased buffering capacity, indicating greater stability. Acetotrophs and hydrogenotrophs were dominated by Methanosarcinaceae and Methanobacteriales, respectively, in both digesters, exhibiting an average ratio of 66‐to‐34% in A and 76‐to‐24% in B during steady‐state.CONCLUSIONThe inoculation strategy in digester B resulted in improved stability, lower propionate concentration and 10% higher relative abundance of acetotrophs. © 2017 Society of Chemical Industry
Modified cuckoo search algorithm in microscopic image segmentation of hippocampus
Authors: Chakraborty Shouvik , Chatterjee Sankhadeep , Dey Nilanjan , Ashour Amira S. , Ashour Ahmed S. , Shi Fuqian , Mali Kalyani 
Published: May 2017

AbstractMicroscopic image analysis is one of the challenging tasks due to the presence of weak correlation and different segments of interest that may lead to ambiguity. It is also valuable in foremost meadows of technology and medicine. Identification and counting of cells play a vital role in features extraction to diagnose particular diseases precisely. Different segments should be identified accurately in order to identify and to count cells in a microscope image. Consequently, in the current work, a novel method for cell segmentation and identification has been proposed that incorporated marking cells. Thus, a novel method based on cuckoo search after pre‐processing step is employed. The method is developed and evaluated on light microscope images of rats’ hippocampus which used as a sample for the brain cells. The proposed method can be applied on the color images directly. The proposed approach incorporates the McCulloch's method for lévy flight production in cuckoo search (CS) algorithm. Several objective functions, namely Otsu's method, Kapur entropy and Tsallis entropy are used for segmentation. In the cuckoo search process, the Otsu's between class variance, Kapur's entropy and Tsallis entropy are employed as the objective functions to be optimized. Experimental results are validated by different metrics, namely the peak signal to noise ratio (PSNR), mean square error, feature similarity index and CPU running time for all the test cases. The experimental results established that the Kapur's entropy segmentation method based on the modified CS required the least computational time compared to Otsu's between‐class variance segmentation method and the Tsallis entropy segmentation method. Nevertheless, Tsallis entropy method with optimized multi‐threshold levels achieved superior performance compared to the other two segmentation methods in terms of the PSNR.
Edge‐colorings avoiding rainbow stars
Authors: Hoppen Carlos , Lefmann Hanno , Odermann Knut , Sanches Juliana 
Published: May 2017

AbstractWe consider an extremal problem motivated by a article of Balogh [J. Balogh, A remark on the number of edge colorings of graphs, European Journal of Combinatorics 27, 2006, 565–573], who considered edge‐colorings of graphs avoiding fixed subgraphs with a prescribed coloring. More precisely, given , we look for n‐vertex graphs that admit the maximum number of r‐edge‐colorings such that at most colors appear in edges incident with each vertex, that is, r‐edge‐colorings avoiding rainbow‐colored stars with t edges. For large n, we show that, with the exception of the case , the complete graph is always the unique extremal graph. We also consider generalizations of this problem.
Automated high throughput analysis of antiretroviral drugs in dried blood spots
Authors: Duthaler U. , Berger B. , Erb S. , Battegay M. , Letang E. , Gaugler S. , Krähenbühl S. , Haschke M. 
Published: May 2017

For therapeutic drug monitoring in remote settings, dried blood spots (DBS) are particularly advantageous, as blood sample collection and handling is uncomplicated. The aim of this study was to develop and validate an automated extraction method for the analysis of nevirapine, efavirenz and lopinavir in DBS samples. Automated extraction was performed with methanol : water (70 : 30 v/v), using a DBS‐MS 500 autosampler coupled to a liquid chromatography tandem mass spectrometry system. The autosampler used digital images of each DBS to position the extraction head, sprayed 10 μl of internal standard onto each DBS and extracted a 4‐mm disc (Ø) from the centre of each spot by unilateral flow using 25‐μl extraction solvent. The analytes were baseline separated on a pentafluorophenyl column and analysed by using electrospray ionization with multiple reaction monitoring in positive polarity mode for nevirapine and lopinavir and in negative mode for efavirenz. The method was linear between 10 and 10 000 ng/ml for all analytes. Automated sample extraction resulted in consistent recoveries (nevirapine: 70 ± 6%, efavirenz: 63 ± 11% and lopinavir: 60 ± 10%) and matrix effects between different donors and concentration levels. Intra‐day and inter‐day accuracy and precision deviations were ≤15%. Manual and automated extractions of DBS samples collected within the framework of an adherence assessment study in rural Tanzania showed good agreements with deviations of less than 10%. Our study highlights that therapeutic drug monitoring samples obtained in the resource‐constrained setting of rural Africa can be reliably determined by automated extraction of DBS. Overall, automatization improved method sensitivity and facilitates analysis of large sample numbers. Copyright © 2017 John Wiley & Sons, Ltd.
The microbial habitat in soil: Scale, heterogeneity and functional consequences
Authors: Nunan Naoise 
Published: May 2017

AbstractThe microbial habitat is rarely studied in soil microbial ecology even though microbial cells are exposed and adapt to their local environmental conditions. The physical environment also constrains interactions among organisms. The nature of microbial communities and their functioning can only be fully understood if their habitat is accounted for. Here, I describe the soil microbial habitat and show how our understanding of microbial functioning has been shaped by this line of investigation.
Comparison of the prognostic values of selected inflammation based scores in patients with medullary thyroid carcinoma: A pilot study
Authors: Jiang Ke , Lei Jianyong , Li Canjun , Shu Kunpeng , Li Wenbin , Zhang Yuwei , Li Zhihui , Gong Rixiang , Zhu Jingqiang 
Published: May 2017

BackgroundThe significance of inflammation based scores including the neutrophil‐to‐lymphocyte ratio (NLR), derived neutrophil‐to‐lymphocyte ratio (dNLR), platelet‐to‐lymphocyte ratio (PLR), lymphocyte‐to‐monocyte ratio (LMR), prognostic nutritional index (PNI), and plasma fibrinogen remains unclear in medullary thyroid carcinoma (MTC). We aimed to compare the prognostic value of these scores.MethodsSeventy‐eight patients newly diagnosed as MTC with operation in our institution from May 2009 to September 2016 were retrospectively evaluated. Receiver operating characteristic (ROC) curves and Kaplan‐Meier analyses were calculated to compare the prognostic value of these scores.ResultsIncreased PLR was predictive of lymph node metastasis (AUC = 0.644, P = 0.022), capsule invasion (AUC = 0.666, P = 0.007), advanced tumor stages (AUC = 0.657, P = 0.011), and recurrence (AUC = 0.655, P = 0.049). Increased fibrinogen was predictive of lymph node metastasis (AUC = 0.669, P = 0.006) and capsule invasion (AUC = 0.631, P = 0.038). Reduced PNI was predictive of recurrence (AUC = 0.655, P = 0.049). Kaplan‐Meier analyses and Cox regression analysis revealed that PLR was a significant predictor for recurrence.ConclusionsPLR, fibrinogen, and PNI are all predictive. Specially, PLR is superior to other inflammation based scores in terms of prognostic ability.
High efficiency broadband GaN HEMT power amplifier based on three‐frequency point matching method
Authors: Cheng Zhiqun , Zhao Ziming , Ke Huajie , Liu Guohua , Dong Zhihua , Gao Steven 
Published: May 2017

AbstractTo cover the working frequency bands of the three mobile carriers of China Mobile, China Telecom, and China Unicom, power amplifiers (PAs) are required to own broadband. A PA with bandwidth 1.3–2.7 GHz is designed (fully covers the operating bands of the three mobile carriers). Measured results show that greater than 68% efficiency is attained over a 75% bandwidth from 1.3 to 2.7 GHz. The output power is larger than 40.2 dBm with gain varying from 10 to 13 dB across the band. In this article, three‐frequency point matching method is applied in order for broadband matching. High‐efficiency is achieved by a specially designed impedance matching topology which realizes short‐circuits of the second harmonics and open‐circuits of the third harmonics at different frequencies. The designed broadband high‐efficiency GaN PA provides a new approach and method for the development of PAs in 4G base stations.
A tri‐band monopole filtering antenna using multimode resonators
Authors: Yao Yue , Tu Zhi‐Hong , Gan Zheng 
Published: May 2017

AbstractA simple tri‐band monopole filtering antenna using multimode resonators is proposed. Two novel microstrip open‐loop multimode resonators and a monopole ring antenna with an open stub are integrated together on the same layer of the substrate. Compared with the traditional monopole antenna, the integration makes the proposed antenna operate at 2.4/5.2/6.5 GHz and realize two radiation zeroes at 2 and 3.3 GHz. It leads to the high selectivity for 2.4 GHz. The measured results, including the reflection coefficient, peak realized gain and radiation pattern agree well with the simulated results.
A ultrawideband antenna with dual‐band band‐notch filters
Authors: Tsai Lin‐Chuan 
Published: May 2017

AbstractThe heptagonal‐shaped monopole antenna design for ultrawideband (UWB) applications is proposed. This antenna is designed on PCB FR4 substrate with relative permittivity ɛr = 4.4, loss tangent tan δ = 0.0245, and thickness h = 1.6 mm. The antenna consists of a radiated patch, a feed line, and a ground plane. With the different geometrical parameters, simulated and experimental results of the antenna are suitable for UWB operations. The bandwidth VSWR < 2 of the UWB antennas from measurement is ∼122.02% (2.63–10.86 GHz). To decrease the interference with the wireless local area networks (WLANs) at 5.2/5.8 GHz and worldwide interoperability for microwave access (WiMAX) at 3.5/5.5 GHz, two band‐notched filters covering from 3.4 to 3.69 and 5.15 to 5.85 GHz was design. Two L‐shaped slots on the patch and two slot‐type split ring resonators (SRRs) on the ground plane were used to produce two band‐notched frequency bands. The results for VSWR, far‐field H‐ and E‐plane radiation patterns and gain of the proposed antennas are presented and discussed. The radiation area of the design antenna is 26 × 16.38 mm2. The measured results show a good agreement with the simulated results.
Flexible microstrip grid array polymer‐conductive rubber antenna for 5G mobile communication applications
Authors: Ramli M. R. , Rahim S. K. A. , Rahman H. A. , Sabran M. I. , Samingan M. L. 
Published: May 2017

AbstractA flexible microstrip grid array antenna (MGAA) fabricated by printing the patch and the ground plane using a 0.25‐mm‐thick conductive rubber layer onto a 1.9 mm thick Polydimethylsiloxane (PDMS) substrate layer is presented in this article. The proposed antenna was designed to operate at 14 GHz frequency band. It is composed of 24 radiating elements to achieve a high gain and compact size characteristics. The measurement results shows that the antenna exhibits wideband characteristics in return loss (S11) covered from 12 to 18 GHz and it can works at bending state without sacrificing the performance. The measured radiation pattern results also present good agreement with the simulated results. All the criteria of this proposed antenna make it as a suitable candidate to be applied for future flexible and conformal‐5G mobile communication applications.
Improved chipless tag based on multifilters
Authors: Ni Yi‐Zhan , Huang Xiao‐Dong , Cheng Chong‐Hu 
Published: May 2017

AbstractIn this study, a novel compact chipless RFID transponder is presented. The coding information is based on spectral signature using three types of multiresonator: spiral, slot, and U‐shaped defected ground structure (DGS). Each resonator can be seen as a band‐stop filter which contributes to a particular resonance frequency. The previous spiral resonator based barcodes have only 1 bit information on each resonator which result in a large quantity of resonators relatively and a long microstrip line. In our design, the slot is cutting on the spiral resonator so more bits can be stored. The combination of slot and spiral resonators together provides an efficient decrease in resonator numbers. The DGS structure takes use of ground plane of the tag which further increases the capacity without expanding the size. The method of using these three types of resonators presents a clear improvement in miniaturizing the transponder which leads to a compact size of the tag. By applying frequency shift coding (FSC) coding technique, a coding density of 0.946 bit/cm2 is achieved. Improvement in two cross‐polarized transmitting and receiving antennas is also considered in the design. Corresponding experiments on realized prototypes are provided to validate the effectiveness of the proposed design.
Three‐dimensional‐folded annular slot antenna‐package
Authors: Shamsinejad Souren , Monavar Fatemeh M. , De Flaviis Franco , Moradi Gholamreza , Mousavi Pedram 
Published: May 2017

AbstractIn this letter, a novel 3D conformal annular slot antenna is proposed and patterned over a 3D printed cubic package with conductive surface in order to achieve a horizontally polarized omnidirectional radiation pattern in the azimuth plane. To verify the concept, a cubic antenna‐package at 2.4 GHz has been designed and fabricated for wireless sensor network applications application. The cube is printed by Objet 3D printer from Verogray material with thickness of 1.55 mm and covered with copper tape with slots being cut out of its surface at appropriate locations. The measurements are in good agreement with simulations. A maximum measured gain of 2.53 dBi at the azimuth plane and a bandwidth of 11% are achieved.
A compact dual‐band hook‐shaped antenna for wireless applications
Authors: Yeo Wei Long , Lai Koon Chun , Yeap Kim Ho , Teh Peh Chiong , Nisar Humaira 
Published: May 2017

AbstractIn this article, a dual‐band coplanar waveguide‐fed antenna is proposed for wireless local network. The dimensions of the antenna are 18 × 17 × 1.6mm3 fabricated on FR‐4 substrate. It comprises narrow hook shaped slits on left‐hand side and two separated ground planes. The measured results show that the proposed antenna has impedance bandwidth from 2.0 to 2.56 GHz and 4.59 to 6.0 GHz for 10 dB return loss. It can cover several wireless communication bands like UMTS 2100 MHz, Bluetooth 2400 MHz, WLAN 2400/5200/5800 MHz, and LTE 2300–2400 MHz bands. To validate the results of simulation, an inexpensive FR‐4 substrate is used for the fabrication of the prototypes of the proposed antenna and tested. Experimental and simulated results obtained indicate that the proposed antenna has good radiation efficiencies and near omnidirectional radiation patterns.
Wideband dual circularly polarized beam‐scanning array for Ka‐band satellite communications
Authors: Zhang Long , Gao Steven , Luo Qi , Li Wenting , Li Qingxia 
Published: May 2017

AbstractThis article presents a wideband dual circularly polarized (CP) array which has two independent beams in orthogonal circular polarizations and the two beams can scan to ±23° individually. The proposed array consists of stacked patches fed by 90° hybrid couplers. To achieve two independent beams, the beam‐forming networks (BFNs) for the left‐hand circular polarization (LHCP) beam and right‐hand circular polarization (RHCP) beam are printed on two separate layers with ground plane between them. This arrangement facilitates the integration of the BFNs and reduces the fabrication complexity. Two prototypes with different beam‐scanning angles are fabricated and measured. The measured results confirm that the array achieves good impedance matching, larger than 20 dB isolation and smaller than 3 dB axial ratio (AR) from 27 to 30 GHz when the array scans to ±23°. Due to the independent beam‐scanning ability, high isolation between the LHCP and RHCP beams and the wide bandwidth, the proposed array is promising for high data‐rate Ka‐band satellite communications which utilize polarization diversity.
Closed‐form expression to optimize the fiber Bragg grating sensor apodization performance
Authors: Chaoui Fahd , Aghzout Otman , Alejos Ana Vazquez , Falcone Francisco , Naghar Azzeddin , El Yakhloufi Mounir 
Published: May 2017

AbstractIn this article, a new closed‐form apodization expression, which describes the light propagation in fiber Bragg grating sensor (FBGS) according to the design setting of the sensor application, is developed and presented. The main goal of the proposed approach is to optimize the FBGS apodization to enhance the reflected power as long as side lobes are kept in a low level. For this purpose, the coupled mode equations (CME) method has been used with the new apodization formula to customize the light propagation in the FBGS. The new apodization algorithm is processed based on side lobe level (SLL) and full width at half maximum (FWHM) of the FBGS grating spectrum. Further, the developed method has been compared with other apodization profiles presented by other authors. All results show very satisfactory performance of the proposed method.
Non‐Foster immittance observed in the full‐range frequency response
Authors: Zhu Anjie , Wang Chun , Xu Kuiwen , Wang Zhiyu , Ye Dexin , Sun Yongzhi , Qiao Shan , Li Changzhi , Ran Lixin 
Published: May 2017

AbstractWe investigate a non‐Foster element implemented with a radio‐frequency operational amplifier theoretically and experimentally, showing that its full‐range frequency response exhibits an inverted Lorentzian resonance, and thus a high‐frequency non‐Foster response can be observed on the right side of the resonance region. This can be used to overcome the technical difficulty in achieving high‐frequency non‐Foster elements.
Experimental research on vehicle‐borne SAR imaging with THz radar
Authors: Yang Qi , Qin Yuliang , Zhang Ke , Deng Bin , Wang Xinyun , Wang Hongqiang 
Published: May 2017

AbstractVehicle‐borne SAR is one of the most important applications of radar systems, playing a more and more major role in civilian and military fields. Vehicle‐borne SAR imaging experiments with a 0.22‐THz radar system are introduced in this letter and the imaging processing based on practical problems is presented. High quality imaging results are obtained after a series of processing such as optimum parameters estimation, harmonic interference correction and vibration compensation. Finally, analyses of the imaging results verify the validity of the imaging processing, which provide support to the practical application of terahertz vehicle‐borne SAR imaging systems.
A novel design of ultra‐high impedance transforming ratio quad‐band matching network
Authors: Barik Rusan Kumar , Karthikeyan S. S. 
Published: May 2017

AbstractIn this article, a novel design of quad‐band matching network (QBMN) with ultra‐high impedance transforming ratios (UHTRs) is proposed and designed based on ABCD matrix method. The QBMN is capable of matching a very large real load impedance at four different frequencies simultaneously. The quad‐band structure is composed of π‐section with series connected coupled lines at each port. The design formulas of QBMN are derived analytically to obtain the quad‐band operation. In order to validate the proposed idea, three examples of QBMN for different load impedances (500, 1000, and 1500 Ω) are considered. Finally, two QBMNs with transforming ratios of 10 and 20 are fabricated and demonstrated. For both the prototypes, the measured S11 is better than 15 dB at all working frequencies. The experimental performances are consistent with the simulated results.
Multi‐optical carrier generation using a microring resonator to enhance the number of serviceable channels in radio over free space optic
Authors: Amiri I. S. , Alavi S. E. , Punthawanunt S. , Yupapin P. , Youplao P. 
Published: May 2017

AbstractA system of radio over free space optic (RoFSO) system using the multi‐optical carriers has been generated by the microring resonators integrating an add/drop filter. These obtained carriers have shown sufficiently stable for propagating in free space channels while experiencing very low dispersion. Moreover, this technique is appropriated for higher capacity that can be serviced in a system of wavelength‐division multiplexing (WDM) RoFSO, where there are 16 carriers created, where each carrier has 12.5 GHz free spectral range (FSR) and 220 MHz full‐width at half‐maximum (FWHM) and 8 orthogonal frequency division multiplex (OFDM) signals, then they separately modulated with 8 out of these 16 carriers. After the modulation, by utilizing an free space optic (FSO) antenna, all carriers have the optical multiplexing and transmission to a FSO channel. On the receiver side, the demultiplexing is performed and finally the performance of the system subsequently is analyzed by calculation of the constellation diagram and error vector magnitude (EVM).
A quad‐band bandpass filter using split‐ring based on T‐shaped stub‐loaded step‐impedance resonators
Authors: Gan Decheng , He Songbai , Dai Zhijiang , Wang Jinchen 
Published: May 2017

AbstractIn this article, a novel design method of multiband bandpass filters (BPFs) which have flexibly tunable center frequencies is presented by using T‐shaped stub‐loaded step‐impedance resonators (SLSIRs)’ multimode characteristics. By controlling the impedance ratios and the length ratios of the T‐shaped open stubs, the center frequencies of a multiband BPF can be decided. To verify the effectiveness of the proposed method, a 1.34/2.2/3.3/4.5 GHz quad‐band filter using split‐ring based on SLSIRs is designed, fabricated, and measured. The proposed filter is composed of a pair of tri‐section T‐shaped open stubs transmission lines, which form a folded split‐ring. By controlling the impedance ratios, the length ratios of the open stubs and the width of the gap of the folded split resonance loop, the quad‐band center frequencies are flexibly tunable. Owing to the 0° feed structure, seven transmission zeros can be realized near the pass‐band for enhancing the selectivity. The measured results show good agreement with the theory and the EM simulation.