bluuebunny/crossref_metadata_2025 huggingface dataset:
First-principles study of nitrogen-doped nanographene as an efficient charge transport and nonlinear optical material
Authors: Muhammad Shabbir , Chaudhry Aijaz Rasool , Irfan Ahmad , Al-Sehemi Abdullah G.
Published: July 2017

The prospective of nitrogen doped graphene (NDG) as useful nonlinear optical (NLO) and charge transport materials is explored using first principles methods.
A green approach to the synthesis of Ag doped nano magnetic γ-Fe2O3@SiO2-CD core–shell hollow spheres as an efficient and heterogeneous catalyst for ultrasonic-assisted A3 and KA2 coupling reactions
Authors: Sadjadi S. , Malmir M. , Heravi M. M.
Published: July 2017

Using a green approach and ultrasonic-assisted template-free five-step process, a novel heterogeneous catalyst, γ-Fe2O3@SiO2-CD/Ag hollow spheres (h-Fe2O3@SiO2-CD/Ag), was fabricated.
Intramolecular alkyne–dithiolium cycloaddition: a joint experimental and DFT mechanistic study
Authors: Wang Cheng , Flinn Christopher , Zhao Yuming
Published: July 2017

The intramolecular alkyne–dithiolium cycloaddition reactions were found to occur through either a concerted or stepwise pathway, depending on the conjugation degree of the alkynyl unit.
Influence of the ultrasonic surface rolling process on stress corrosion cracking susceptibility of high strength pipeline steel in neutral pH environment
Authors: Wang Bingying , Yin Yu , Gao Zhiwei , Hou Zhenbo , Jiang Wenchun
Published: July 2017

A developed surface enhancement technique, USRP, was applied on X80 pipeline steel and the stress corrosion cracking susceptibility was studied.
The value of pyrans as anticancer scaffolds in medicinal chemistry
Authors: Kumar Dinesh , Sharma Pooja , Singh Harmanpreet , Nepali Kunal , Gupta Girish Kumar , Jain Subheet Kumar , Ntie-Kang Fidele
Published: July 2017

Pyran-based heterocycles are promising for anticancer drug discovery.
A facile approach for photoelectrochemical performance enhancement of CdS QD-sensitized TiO2via decorating {001} facet-exposed nano-polyhedrons onto nanotubes
Authors: Ding Dong , Zhou Bo , Liu Shurong , Zhu Guijie , Meng Xianwei , Yang Jiandong , Fu Wuyou , Yang Haibin
Published: July 2017

We designed a novel TiO2 hybrid structure with enhanced PEC performance that combined a large amount of {001} facets exposed on nano-polyhedrons and nanotubes.
Upconversion luminescence enhancement and temperature sensing behavior of F− co-doped Ba3Lu4O9:Er3+/Yb3+ phosphors
Authors: Liu Songbin , Liu Shuifu , Zhou Ming , Ye Xinyu , Hou Dejian , You Weixiong
Published: July 2017

F− doping to enhance upconversion luminescence and temperature sensitivity of Ba3Lu4O9:Er3+/Yb3+ (EYBLO) phosphors is ascribed to the modification of local crystal field of activator ions and reduction of crystal site symmetry.
Preparation of an ultrathin 2D/2D rGO/g-C3N4 nanocomposite with enhanced visible-light-driven photocatalytic performance
Authors: Yu Kun , Hu Xiaofeng , Yao Kaiyuan , Luo Ping , Wang Xiuyuan , Wang Huihu
Published: July 2017

An ultrathin 2D/2D rGO/g-C3N4 nanocomposite was constructed using thermally exfoliated g-C3N4 nanosheets and graphene oxide (GO) as precursors by a simple solvent method.
Syntheses, crystal structures, and magnetic properties of cyclic dimer Ln2L2 complexes constructed from (3-pyridinylmethoxy)phenyl-substituted nitronyl nitroxide ligands
Authors: Zhu Mei , Li Yang , Jia Lingjie , Zhang Li , Zhang Wei
Published: July 2017

Herein, five lanthanide-radical cyclic dimer complexes have been obtained and complex Tb shows the relaxation behavior in zero dc field with an anisotropy barrier Δ/kB = 21.6 K.
Impeding phonon transport through superlattices of organic–inorganic halide perovskites
Authors: Singh Rahul , Balasubramanian Ganesh
Published: July 2017

Strong phonon incoherence in perovskite superlattices reduces the thermal conductivity.
A novel electron carrier molecule based on a viologen derivative for visible light-driven CO2 reduction to formic acid with the system of zinc porphyrin and formate dehydrogenase
Authors: Ikeyama S. , Amao Y.
Published: July 2017

An effective visible light-driven CO2 reduction to formic acid system was developed with zinc porphyrin, formate dehydrogenase and 1,1′-diaminoethyl-4,4′-bipyridinium salt.
Mechanical response of collagen networks to nonuniform microscale loads
Authors: Burkel Brian , Notbohm Jacob
Published: July 2017

Contractile particles are used to apply local forces within collagen networks, and the resulting displacement fields are quantified.
Dielectrophoretic assembly of dimpled colloids into open packing structures
Authors: Jia Zhuoqiang , Sacanna Stefano , Lee Stephanie S.
Published: July 2017

Particle shape anisotropy enabled electric field-induced reversible solid-state phase transitions in two-dimensional colloidal crystals comprising dimpled spherical colloids.
Enhanced thermoelectric properties of screen-printed Bi0.5Sb1.5Te3 and Bi2Te2.7Se0.3 thick films using a post annealing process with mechanical pressure
Authors: Choi Hyeongdo , Kim Sun Jin , Kim Yongjun , We Ju Hyung , Oh Min-Wook , Cho Byung Jin
Published: July 2017

We report on a TE device composed of p-type Bi0.5Sb1.5Te3 and n-type Bi2Te2.7Se0.3 TE materials prepared using a screen-printing process.
1,4-Azaborine as a controller of triplet energy, exciton distribution, and aromaticity in [6]cycloparaphenylenes
Authors: Wu Jie , Kan Yuhe , Xue Zhenhua , Huang Jintian , Chen Peng , Yu Xiaofang , Guo Zeyu , Su Zhongmin
Published: July 2017

Introduction of 1,4-azaborine rings at different positions of the [6]CPP hoop can efficiently control distribution of triplet excitons, triplet-state aromaticity, and triplet energy in [6]CPP.
Oriented columnar films of a polar 1,2,3-triazole-based liquid crystal prepared by applying an electric field
Authors: Nguyen Manh Linh , Shin Tae Joo , Kim Ho-Joong , Cho Byoung-Ki
Published: July 2017

A polar liquid crystal based on the 1,2,3-triazolyl group forms high-quality oriented columnar films under an electric field.
The ‘Goldilocks zone’ of fatty acid metabolism; to ensure that the relationship with cardiac function is just right
Authors: Kerr Matthew , Dodd Michael S. , Heather Lisa C.
Published: July 2017

Fatty acids (FA) are the main fuel used by the healthy heart to power contraction, supplying 60–70% of the ATP required. FA generate more ATP per carbon molecule than glucose, but require more oxygen to produce the ATP, making them a more energy dense but less oxygen efficient fuel compared with glucose. The pathways involved in myocardial FA metabolism are regulated at various subcellular levels, and can be divided into sarcolemmal FA uptake, cytosolic activation and storage, mitochondrial uptake and β-oxidation. An understanding of the critical involvement of each of these steps has been amassed from genetic mouse models, where forcing the heart to metabolize too much or too little fat was accompanied by cardiac contractile dysfunction and hypertrophy. In cardiac pathologies, such as heart disease and diabetes, aberrations in FA metabolism occur concomitantly with changes in cardiac function. In heart failure, FA oxidation is decreased, correlating with systolic dysfunction and hypertrophy. In contrast, in type 2 diabetes, FA oxidation and triglyceride storage are increased, and correlate with diastolic dysfunction and insulin resistance. Therefore, too much FA metabolism is as detrimental as too little FA metabolism in these settings. Therapeutic compounds that rebalance FA metabolism may provide a mechanism to improve cardiac function in disease. Just like Goldilocks and her porridge, the heart needs to maintain FA metabolism in a zone that is ‘just right’ to support contractile function.
Fit-to-Targets for the Desired Sensation Level Version 5.0a Hearing Aid Prescription Method for Children
Authors: Moodie Sheila T. F. ,   The Network of Pediatric Audiologists of Canada, Scollie Susan D. , Bagatto Marlene P. , Keene Kelley
Published: July 2017

Purpose

The purpose of this study was to measure the range of fit to Desired Sensation Level version 5.0 (DSL v5.0) targets in pediatric practice environments. Results will be used in the future to develop clinical-aided speech intelligibility index typical performance data.

Method

Clinical partners collected data from 161 final hearing aid settings for children aged ≤ 10 years. Measured data were obtained by performing 2-cm
3
coupler-simulated real-ear measurements using the DSL v5.0 implementation on the Audioscan VF-1 (Etymonic Design Inc., Dorchester, ON, Canada) for soft, average, and loud speech inputs and maximum hearing aid output levels.

Results

Fittings were within ± 5-dB root-mean-square (RMS) error of target for 77%, 80%, and 82% of fittings for the soft, medium, and loud speech test levels, respectively. Aided maximum power output measures were within ± 5-dB RMS error in 72% of cases. Degree of hearing loss, test frequency, and frequency by test level were significant factors in deviation from target. The range of aided speech intelligibility index values exhibited a strong correlation with the hearing levels of the children tested.

Conclusion

This study provides evidence that typical hearing aid fittings for children can be achieved within ± 5-dB RMS error of the DSL v5.0 target. Greater target deviations were observed at extreme frequencies and as the severity of hearing loss increased.
Working Memory and Speech Recognition in Noise Under Ecologically Relevant Listening Conditions: Effects of Visual Cues and Noise Type Among Adults With Hearing Loss
Authors: Miller Christi W. , Stewart Erin K. , Wu Yu-Hsiang , Bishop Christopher , Bentler Ruth A. , Tremblay Kelly
Published: July 2017

Purpose

This study evaluated the relationship between working memory (WM) and speech recognition in noise with different noise types as well as in the presence of visual cues.

Method

Seventy-six adults with bilateral, mild to moderately severe sensorineural hearing loss (mean age: 69 years) participated. Using a cross-sectional design, 2 measures of WM were taken: a reading span measure, and Word Auditory Recognition and Recall Measure (Smith, Pichora-Fuller, & Alexander, 2016). Speech recognition was measured with the Multi-Modal Lexical Sentence Test for Adults (Kirk et al., 2012) in steady-state noise and 4-talker babble, with and without visual cues. Testing was under unaided conditions.

Results

A linear mixed model revealed visual cues and pure-tone average as the only significant predictors of Multi-Modal Lexical Sentence Test outcomes. Neither WM measure nor noise type showed a significant effect.

Conclusion

The contribution of WM in explaining unaided speech recognition in noise was negligible and not influenced by noise type or visual cues. We anticipate that with audibility partially restored by hearing aids, the effects of WM will increase. For clinical practice to be affected, more significant effect sizes are needed.
Improved DOA estimation algorithm for co‐prime linear arrays using root‐MUSIC algorithm
Authors: Zhang Dong , Zhang Yongshun , Zheng Guimei , Feng Cunqian , Tang Jun
Published: July 2017

The problem of direction of arrival (DOA) estimation with co‐prime linear arrays is researched. An improved DOA estimation algorithm based on root‐multiple signal classification (MUSIC) is proposed. The method can solve the matching error problem in Sun's algorithm. In addition, it can make full use of signal space and noise space to improve the estimation accuracy with low complexity. Experimental results verify the validity of the proposed algorithm.
Spectral efficiency enhancement of multiresolution multiplexing
Authors: Alasti H.
Published: July 2017

A novel approach is proposed for spectral efficiency enhancement of multiresolution multiplexing (MM), when carrier to noise is low. MM is introduced as a baseband multiple‐input, multiple‐output system. The reliable capacity bound is discussed for MM, when successive interference cancellation algorithm is used as optimal detector at receiver. The spectral efficiency of the enhanced MM is evaluated and compared with the spectral efficiency of quadrature amplitude modulation of the same constellation size. A basic adaptive loading design towards spectral efficiency enhancement is presented.
Gate bias system for OTFT electrical characterisation and low‐frequency noise measurements
Authors: Ciofi C. , Scandurra G. , Giusi G.
Published: July 2017

It is shown how some photovoltaic MOSFET drivers can be used for the realisation of a low noise, programmable voltage source, with a dynamic range that can easily exceed several tens of volts starting from standard ± 12 V power supplies. Such a source can be useful in the investigation of the electrical properties, and particularly noise properties, of organic thin film transistors on plastic substrates, since relatively large gate voltage sweeps are required in order to obtain a significant change in the conduction properties of the channel.
Joint recovery of carrier frequency and symbol timing for extremely bandwidth‐efficient satellite links
Authors: Gappmair Wilfried , Plimon Karin , Ebert Johannes , Bergmann Michael
Published: July 2017

Efficient estimation and synchronisation of transmission parameters is key for any satellite receiver, which is especially true for the recovery of carrier frequency and symbol timing. In this respect, a joint feedback solution has been analysed and tested in some recent work conducted by the authors. However, it turned out that the capture range of the carrier frequency is limited by the selected roll‐off factor (excess bandwidth), which means that the synchroniser would not work properly for extremely bandwidth‐efficient transmission schemes. This motivated them to modify the feedback structure by introducing a different filter operated in parallel to the receiver matched filter. In the sequel, it could be verified by analytical and simulation results that the initial frequency offset synchronised successfully can reach up to ±50% of the symbol rate irrespective of the selected modulation scheme, the roll‐off factor, the signal‐to‐noise ratio value and the timing offset the satellite link is operated with. On top of that, a non‐linear modification of the timing error detector has been investigated in detail, since the output of the conventional solution is nullified in case of extremely small excess bandwidths.
Bidirectional satellite communication under same frequency transmission with non‐linear self‐interference reduction algorithm
Authors: Tang Chengkai , Zhang Lingling , Zhang Yi , Song Houbing
Published: July 2017

Two‐way (on‐frequency) relaying using simple amplify‐and‐forward processing at the satellite isan emerging technology that allows doubling of system spectral efficiency forcertain networking applications. However, the satellite channel is non‐linearand compensation for the self‐interfering signal is more difficult than onlinear channels, especially when memory effects are recognised. In this paper, we model two‐user, asynchronous, bidirectional relaying for uncodedtransmission, and proposed a bidirectional satellite communication algorithmunder same frequency transmission. First, we employ a table addressed byside‐information and the symbol to be detected to model the action of thechannel. Then, we employ a linear adaptive canceler followed by a smaller tablelookup process to cancel the self‐interference and to make decisions. In thesimulation part, we focus in the results section is upon 16‐amplitude phaseshift keying (APSK), widely employed in the DVB‐S2 standard forbandwidth‐efficient operation. Compared with the existing bidirectionalsatellite communication algorithm, our proposed algorithm have the far lesscomplexity and training time at the similar performance.
Sliding mode‐based active disturbance rejection control for vehicle steer‐by‐wire systems
Authors: Sun Zhe , Zheng Jinchuan , Man Zhihong , Wang Hai , Lu Renquan
Published: July 2017

This study presents a sliding mode‐based active disturbance rejection control (SMADRC) scheme for a steer‐by‐wire (SbW) system in road vehicles. First, a plant model that describes the mechanical dynamics of the SbW system is elaborated, where the viscous friction and the self‐aligning torque are regarded as external disturbances. Second, the design of SMADRC is exposited, in which a non‐linear extended state observer is utilised to estimate the non‐linearities existing in the plant model, and a sliding mode control component is used to cope with the effect of the non‐linearities and guarantee the control robustness against system uncertainties and varying road conditions. Finally, experimental results are shown to demonstrate the superiority of the designed SMADRC in comparison with a conventional sliding mode controller and a PD‐based active disturbance rejection controller (PDADRC).
Texture classification by multifractal spectrum and barycentric coordinates of bit planes of wavelet coefficients
Authors: Wang Shuli , Wang Guanxiang
Published: July 2017

A new texture classification method based on wavelet transform is presented. The elements of the signature vector, FDBC, of an image are the fractal dimensions and barycentric coordinates of the bit planes of the wavelet coefficients in both the three‐level high‐frequency domains and the third low‐frequency domain. The pretreatment is done with SVD decomposition and reconstruction by dropping half singular values. The one‐nearest‐neighbour classifier (1NN) with distance is used to make the classification. Furthermore, to improve classification result, the classifier 1NN is strengthened with weighted distance. The proposed method is tested on five subsets from Brodatz database and UMD database and is experimentally proved more efficient and more promising.
High voltage gain interleaved DC–DC converter with minimum current ripple
Authors: Fekri Mahmoud , Molavi Navid , Adib Ehsan , Farzanehfard Hosein
Published: July 2017

A new interleaved high step‐up DC–DC converter is presented in this study which integrates coupled inductors and voltage multipliers techniques into interleaved structure to provide high voltage gain without extreme duty cycle. The voltage stress across power metal–oxide–semiconductor field‐effect transistors is very low, so low voltage rating switches with lower Rds(on) can be used. A modified version of winding cross‐coupled inductors technique is employed to minimise the input current ripple, and also the reverse recovery problem of the output diodes is alleviated because of the leakage inductance of the coupled inductors. Also, the leakage energy is absorbed and recycled to the output by the passive clamp scheme. In addition, automatic current sharing performance between the interleaved phases is established without any extra circuit. The operating principles of the proposed converter are explained and the theoretical analysis is provided, and in order to verify the effectiveness of the proposed converter, a 170 W, 30–360 V laboratory prototype is implemented.
Six‐phase interleaved boost dc/dc converter with high‐voltage gain and reduced voltage stress
Authors: Maalandish Mohammad , Hosseini Seyed Hossein , Ghasemzadeh Saeed , Babaei Ebrahim , Shalchi Alishah Rasoul , Jalilzadeh Tohid
Published: July 2017

In this study, a new non‐isolated six‐phase interleaved boost dc–dc converter is presented for photovoltaic (PV) applications. The suggested structure consists of two symmetric three‐phase interleaved boost dc–dc converters along with two switched‐capacitor cells, in order to obtain high conversion ratio. For different values of duty‐cycles, the voltage conversion ratio of the proposed topology is high. Also, the voltage stress of switches for various duty cycles is low and the efficiency of proposed topology is high. Moreover, the value of input current ripple is low with the utilisation of interleaving techniques. These advantages cause the proposed topology to be a good candidate for PV systems. The operation modes and mathematical analysis of the presented converter is introduced. In order to show the merits of presented converter, comparison results with other boost dc/dc converters are provided. Both experimental and simulation works based 453 W are presented to verify the operation of recommended converter. PSCAD/EMTDC software is used for simulation work.
Challenges, advances and future directions in protection of hybrid AC/DC microgrids
Authors: Mirsaeidi Sohrab , Dong Xinzhou , Shi Shenxing , Tzelepis Dimitrios
Published: July 2017

Hybrid microgrids which consist of AC and DC subgrids interconnected by power electronic interfaces have attracted much attention in recent years. They not only can integrate the main benefits of both AC and DC configurations, but also can reduce the number of converters in connection of distributed generation sources, energy storage systems and loads to AC or DC buses. In this study, the structure of hybrid microgrids is discussed, and then a broad overview of the available protection devices and approaches for AC and DC subgrids is presented. After description, analysis and classification of the existing schemes, some research directions including communication infrastructures, combined control and protection schemes, and promising devices for the realisation of future hybrid AC/DC microgrids are pointed out.
Performance and economic analysis of a 27 kW grid‐connected photovoltaic system in Suriname
Authors: Raghoebarsing Amrita , Kalpoe Anand
Published: July 2017

The performance of a grid‐connected photovoltaic (PV) system, under the Surinamese weather conditions, is monitored and reported. A measurement and data‐logging system provides inputs for the calculation of selected standard key performance indicators (KPI). Calculated KPI's are compared to expected values obtained from modelling the system using the PVSyst software. In addition, results from selected comparable studies are also used to compare the computed KPI's. Using one year data, the annual energy yield (Eac) totalled 37 MWh. This value is 6% higher than the one obtained from the modelling software. The calculated performance ratio (PR) and capacity factor (CF) of 74.5 and 15.5%, respectively, are also higher than the ones obtained from PVSyst. The difference can be attributed to the irradiance data (satellite data, monthly averages) used for input in the PVSyst software. The above mentioned calculated values for the PR and CF compared favourably with internationally reported values for systems located in regions with similar weather patterns. Using a total investment cost of 109,000 USD the levelised cost of energy (LCOE) calculated with the RETScreen software equals USD 0.36 /kWh. This LCOE is three times the current energy price in Suriname.
Inertial response from wind power plants during a frequency disturbance on the Hydro‐Quebec system – event analysis and validation
Authors: Asmine Mohamed , Langlois Charles‐Éric , Aubut Noël
Published: July 2017

To better assess the contribution of wind power plants (WPPs) during disturbances, Hydro‐Québec TransÉnergie (HQT), the main transmission system operator in the Quebec Interconnection, uses on‐line monitoring to record data at the point of common coupling of each WPP. This data is used to analyse their performance during voltage and frequency disturbances. Until recently, very few WPPs were able to provide an inertial response (IR) for under‐frequency events. On 28 December 2015, a generation loss of 1700 MW caused a frequency nadir of 59.08 Hz on the system, to which most WPPs required to provide IR contributed significantly. The analysis of the event showed that the behaviour of the WPPs had a significant effect on the recovery of the system frequency. This study presents the performance analysis of WPPs during this under‐frequency event. The analysis is based on data collected from 25 large‐scale WPPs in operation and equipped with the IR feature as required by HQT. Field measurements and simulation results are used to emphasise the effect of the active power reduction during the recovery phase. Impacts of the IR from the WPPs as used on the Hydro‐Quebec system are discussed.
Underdetermined passive localisation of emitters based on multi‐dimensional spectrum estimation techniques
Authors: Chen Minqiu , Mao Xingpeng , Xin Liang
Published: July 2017

One‐step passive localisation methods are verified to outperform the conventional two‐step methods in terms of estimation accuracy and identifiability. However, the existing one‐step algorithms still cannot work in the scenario where the number of emitters exceeds the total number of sensors from all the base stations. Based on a spatio‐temporal processing procedure, the authors propose a novel localisation model, which has the form of multi‐dimensional harmonic retrieval. By utilising multi‐dimensional spectrum estimation techniques, the underdetermined localisation problem can be handled thanks to the increase of model's degree of freedom. To further improve the identifiability, a nested‐array‐based localisation model is also given based on the multi‐dimensional processing framework. Simulation results demonstrate that the novel‐model‐based Capon algorithm can achieve higher localisation accuracy without the prior knowledge about the number of emitters, and is robust to the correlated noise.
Metallicity effect on stellar granulation detected from oscillating red giants in open clusters
Authors: Corsaro E. , Mathur S. , García R. A. , Gaulme P. , Pinsonneault M. , Stassun K. , Stello D. , Tayar J. , Trampedach R. , Jiang C. , Nitschelm C. , Salabert D.
Published: July 2017

Context. The effect of metallicity on the granulation activity in stars, and hence on the convective motions in general, is still poorly understood. Available spectroscopic parameters from the updated APOGEE-Kepler catalog, coupled with high-precision photometric observations from NASA’s Kepler mission spanning more than four years of observation, make oscillating red giant stars in open clusters crucial testbeds.

Aims. We aim to determine the role of metallicity on the stellar granulation activity by discriminating its effect from that of different stellar properties such as surface gravity, mass, and temperature. We analyze 60 known red giant stars belonging to the open clusters NGC 6791, NGC 6819, and NGC 6811, spanning a metallicity range from [Fe/H] ≃ − 0.09 to 0.32. The parameters describing the granulation activity of these stars and their frequency of maximum oscillation power, νmax, are studied while taking into account different masses, metallicities, and stellar evolutionary stages. We derive new scaling relations for the granulation activity, re-calibrate existing ones, and identify the best scaling relations from the available set of observations.

Methods. We adopted the Bayesian code Diamonds for the analysis of the background signal in the Fourier spectra of the stars. We performed a Bayesian parameter estimation and model comparison to test the different model hypotheses proposed in this work and in the literature.

Results. Metallicity causes a statistically significant change in the amplitude of the granulation activity, with a dependency stronger than that induced by both stellar mass and surface gravity. We also find that the metallicity has a significant impact on the corresponding time scales of the phenomenon. The effect of metallicity on the time scale is stronger than that of mass.

Conclusions. A higher metallicity increases the amplitude of granulation and meso-granulation signals and slows down their characteristic time scales toward longer periods. The trend in amplitude is in qualitative agreement with predictions from existing 3D hydrodynamical simulations of stellar atmospheres from main sequence to red giant stars. We confirm that the granulation activity is not sensitive to changes in the stellar core and that it only depends on the atmospheric parameters of stars.
On-Water Silver(I)-Catalyzed Cycloisomerization of Acetylenic Free Amines/Amides towards 7-Azaindole/Indole/Isoquinolone Derivatives
Authors: Xie Qiong , Shao Liming , Sun Hongpeng , Xiao Li , Li Wei
Published: July 2017

Silver-catalyzed on-water intramolecular cyclization of acetylenic free amines is reported, which affords 7-azaindoles in good to excellent yields. Neither strong base/acid catalysts nor N-substituted substrates are required to achieve this cycloisomerization. Hydrogen bonds between water medium and the substrates play an important role in improving chemical reactivity and regioselectivity. Furthermore, the on-water reaction is extendable to acetylenic amides for isoquinolone synthesis.
Appendiceal Intussusception: A Diagnostic Challenge
Authors: Nica Adriana , Lakovski Yaniv , Freud Enrique , Samuk Inbal
Published: July 2017

Introduction Appendiceal intussusception is a rare condition in children characterized by an invagination of the appendix into the cecum to various degrees. The treatment is appendectomy; however since symptoms are not specific, clinical diagnosis is challenging and frequently only intraoperative. We present a series of five patients with appendiceal intussusception and discuss features that may direct the pediatric surgeon to achieve early recognition and provide optimal treatment.

Materials and Methods The database of a tertiary medical center was retrospectively reviewed for all patients treated for appendiceal intussusception during the period from January 1995 to January 2016. Data collected by chart review included demographics, clinical characteristics, imaging studies, surgical technique, and outcome. The findings were analyzed by descriptive statistics.

Results This series included five patients (two females and three males) with ages ranging between 27 and 42 months (mean: 35.2). Patients presented with intermittent abdominal pain (IAP, all five patients), alternate vomiting (three of five patients), alternate diarrhea (two of five patients), fever (two of five patients), and rectal bleeding (one of five patients). The average length of symptoms was 22.6 days. Eighteen diagnostic studies were performed, including abdominal ultrasound for all patients, barium enema for three patients with secondary ileocolic intussusception, and abdominal computed tomography (CT) for one patient. The average number of studies per patient was 3.6. In surgery, the appendiceal intussusception was found to be complete in four patients, whereas it was partial in the remaining patient. In all patients, appendectomy was performed with resection of a small rim of cecal wall due to marked congestion and edema in an attempt to decrease recurrence.

Conclusion The mainstay of clinical presentation is intermittent abdominal pain while patients may be completely asymptomatic between attacks. Appendiceal intussusception may act as a leading point to ileocolic intussusception and is frequently concealed by it. The treatment is appendectomy. Both pediatric surgeons and radiologists should be aware of this occurrence to provide adequate management and avoid complications.
A Comparison of Rollback Ratio between Bicruciate Substituting Total Knee Arthroplasty and Oxford Unicompartmental Knee Arthroplasty
Authors: Iriuchishima Takanori , Ryu Keinosuke
Published: July 2017

The purpose of this study was to compare the rollback ratio in bicruciate substituting (BCS) total knee arthroplasty (TKA) and bicruciate-retaining Oxford unicompartmental knee arthroplasty (UKA). In this study, 64 subjects (64 knees) undergoing BCS-TKA (Journey II: Smith and Nephew) and 50 subjects (50 knees) undergoing Oxford UKA (Zimmer-Biomet holdings, Inc., IN) were included. Approximately 6 months after surgery, and when the subjects had recovered their knee range of motion, following the Laidlow's method, lateral radiographic imaging of the knee was performed with active full knee flexion. The most posterior tibiofemoral contact point was measured for the evaluation of femoral rollback (rollback ratio). Flexion angle was also measured using the same radiograph and the correlation of rollback and flexion angle was analyzed. As a control, radiographs of the asymptomatic contralateral knees of subjects undergoing Oxford UKA were evaluated (50 knees). The rollback ratios of the BCS-TKA, Oxford UKA, and control knees were 37.9 ± 4.9, 35.7 ± 4.2, and 35.3 ± 4.8% respectively. No significant difference in rollback ratio was observed among the three groups. The flexion angles of the BCS-TKA, Oxford UKA, and control knees were 123.8 ± 8.4, 125.4 ± 7.5, and 127 ± 10.3 degrees, respectively. No significant difference in knee flexion angle was observed among the three groups. Significant correlation between rollback ratio and knee flexion angle was observed (p = 0.002; Pearson's correlation coefficient = − 0.384). BCS-TKA showed no significant difference in rollback ratio when compared with control knees and Oxford UKA knees. The BCS-TKA design is likely to reproduce native anterior cruciate ligament and posterior cruciate ligament function, and native knee rollback.
Infrapatellar Fat Pad Impingement: A Systematic Review
Authors: Genin Jason , Faour Mhamad , Ramkumar Prem , Yakubek George , Khlopas Anton , Chughtai Morad , King Dominic , Mont Michael
Published: July 2017

Infrapatellar fat pad impingement represents a source of anterior knee pain that is often overlooked. Due to the scarcity of reports related to this disorder, we conducted a systematic review of the literature related to infrapatellar fat pad impingement in evaluating the following: (1) clinical presentation, (2) imaging, (3) management, and (4) clinical outcomes. A systematic review was conducted investigating all available primary literature related to the clinical presentation, imaging, management, and outcomes of infrapatellar fat pad impingement syndrome. A total of 15 studies (9 case reports, 1 case series, and 5 retrospective studies) comprising 167 patients met eligibility criteria for this review. Patients with infrapatellar fat pad impingement were found to most often present with anterior knee pain that worsened with activity, and was frequently associated with trauma. Anterior knee pain, tenderness to palpation over the patellar tendon, loss in terminal extension, and pain with direct pressure on the medial or lateral side of the patella with the knee extended was often found on examination. Although patients may have classic imaging findings on magnetic resonance imaging (localized edema of the infrapatellar fat pad, deep fluid-filled infrapatellar bursa, nonvisualization of clefts, fibrosis, and calcifications), not all patients had positive imaging findings, thus making infrapatellar fat pad impingement a clinical diagnosis. Treatment begins with nonoperative management, but in recalcitrant cases, patients can be surgically treated with arthroscopic fat pad resection. Most patients who undergo operative treatment report improvement or complete resolution of symptoms in terms of pain and range of motion, and are able to return to work. To the best of our knowledge, this is the first comprehensive review on infrapatellar fat pad impingement to better aid the orthopaedic surgeons in diagnosing, treating, and managing patient expectations for this often overlooked knee pathology.
Auf der Suche
Authors: Höffken Dirk
Published: July 2017

Menschenbilder in der psychiatrischen Pflege Beeinflusst das Menschenbild
die Beziehungsarbeit in der psychiatrischen Pflege? Auf jeden Fall, findet unser
Autor und plädiert dafür, Patienten nicht als defekte Maschine, sondern als
Suchende zu betrachten. Denn dann macht es wenig Sinn, Symptome ausschließlich
medikamentös zu unterdrücken. Stattdessen ermöglicht es den Pflegenden, die
Rolle des reflektierenden und reflektierten Begleiters einzunehmen und den
Patienten bei der Suche nach seinem eigenen Weg zu unterstützen.
Analysis of the reverse I-V characteristics of diamond-based PIN diodes
Authors: Saremi Mehdi , Hathwar Raghuraj , Dutta Maitreya , Koeck Franz A. M. , Nemanich Robert J. , Chowdhury Srabanti , Goodnick Stephen M.
Published: July 2017

Diamond is one of the most promising candidates for high power and high temperature applications, due to its large bandgap and high thermal conductivity. As a result of the growth and fabrication process of diamond-based devices, structural defects such as threading dislocations (TDs) may degrade the electrical properties of such devices. Understanding and control of such defects are important for improving device technology, particularly the reverse breakdown characteristics. Here, we show that the reverse bias current-voltage characteristics in diamond PIN diodes can be described by hopping conduction and Poole-Frenkel emission through TDs over the temperature (T) range of 323 K < T < 423 K, for typical values of the TD density found in epitaxially grown materials.
Assessment of distribution networks performance considering residential photovoltaic systems with demand response applications
Authors: Shamshiri Meysam , Gan Chin Kim , Omar Rosli
Published: July 2017

The large penetration of solar photovoltaic (PV) systems at low voltage (LV) networks has started to introduce new challenges to distribution network operators. With the emergence of smart grid technology, the demand response (DR) has been identified as one of the promising approaches for network operators to increase operational flexibility, particularly in the presence of renewable energy resources. Therefore, it is important to investigate how DR applications at a LV consumer level can help to improve network performance. However, so far, only a limited number of works have addressed the implications of DR at LV networks with a PV system. The parametric analysis of the benefits of DR has not been adequately addressed for LV networks with multiple DR-PV interaction scenarios. In this regard, three case studies have been considered in this work, namely, consumers who respond to their own demand profile, consumers who respond to the PV generation profile, and the optimized demand response from consumers. The fractal-based approach has been utilized to model a large number of urban LV networks. Subsequently, the particle swarm optimization technique is utilized to model individual consumers' optimized DR profiles. Comprehensive network case studies are performed considering 100 urban LV network samples under the influence of different DR-PV scenarios. The results suggest that with 100% PV penetration, DR applications at a residential consumer level can achieve 32% peak reduction, reduce network losses by 42%, and achieve 12% load factor increment for the optimized demand response case.
Effect of strain on band alignment of GaAsSb/GaAs quantum wells
Authors: Jones Christina M. , Kioupakis Emmanouil
Published: July 2017

GaAsSb/GaAs quantum wells are of great interest for optical communications; however, their band alignment properties are not fully understood, particularly at 35% Sb alloy concentration used for emission at 1.3 μm. We use device simulation methods based on the 8 × 8 k·p theory to explore the effects of GaAsSb/GaAs quantum well composition, width, and strain on the band alignment. Strain-relaxed wells demonstrate type-I alignment and pseudomorphic wells demonstrate type-II alignment, regardless of quantum-well composition or thickness for wells wider than 3 nm. For partially strain-relaxed wells, we determine the band alignment as a function of the interplay of composition, width, and strain. Our calculated results at various strain conditions agree well with published experimental data. This work provides insight on band alignment of GaAsSb/GaAs quantum wells, as well as of embedded quantum dots with strong confinement along the out-of-plane direction.
Effects of magnetic field profile near anode on ion acceleration characteristics of a diverging magnetic field electrostatic thruster
Authors: Ichihara D. , Iwakawa A. , Sasoh A.
Published: July 2017

In this study, we investigated the effects of the magnetic field profile near a ring anode on the ion acceleration characteristics of a diverging magnetic field electrostatic thruster. In an examined electrostatic thruster, a diverging magnetic field is applied in the ion acceleration region, which comprises a ring anode and an insulating plate in the upstream and an off-axis hollow cathode in the downstream. The ionization near the ring anode inner surface is enhanced by increasing the axial magnetic field in the interior of the ring anode to 250 mT, thereby increasing the effective voltage for the ion acceleration. By supplying 0.41 mg/s argon gas as the working gas through a circular slit between the ring anode and the insulating plate, with a discharge voltage of 200 V, the working gas is almost fully ionized and accelerated to an average energy of 190 eV with a beam diverging angle of 39°.
Broadband sound transmission loss of a large-scale membrane-type acoustic metamaterial for low-frequency noise control
Authors: Ang Linus Yinn Leng , Koh Yong Khiang , Lee Heow Pueh
Published: July 2017

Recent works have demonstrated the potential of small-scale membrane-type acoustic metamaterials for low-frequency (<500 Hz) noise control. Such a phenomenon is attributed to the resonant behavior of the overhanging membrane in each unit cell. Considering industrial applications, large-scale designs may be preferred. This study presents a large-scale (0.8 × 0.8 m2) membrane-type acoustic metamaterial (or the meta-panel), which was evaluated experimentally and verified numerically. Experimental results showed that a broadband sound transmission loss (STL) improvement could be achieved by the incorporated membrane (up to 7.4 dB at 380 Hz). Numerically, parametric studies showed that the broadband STL performance of the meta-panel was due to not only the resonant behavior of the overhanging membrane but also the resonant behavior of the sandwiched membrane along the boundaries of the unit cells. If properly designed, this resonant behavior of the sandwiched membrane could complement membrane-type acoustic metamaterials to achieve an extended good STL performance across a broader frequency bandwidth.
Broadband conversion of microwaves into propagating spin waves in patterned magnetic structures
Authors: Mushenok F. B. , Dost R. , Davies C. S. , Allwood D. A. , Inkson B. J. , Hrkac G. , Kruglyak V. V.
Published: July 2017

We have used time-resolved scanning Kerr microscopy and micromagnetic simulations to demonstrate that, when driven by the spatially uniform microwave field, the edges of patterned magnetic samples represent both efficient and highly tunable sources of propagating spin waves. The excitation is due to the local enhancement of the resonance frequency induced by the non-uniform dynamic demagnetizing field generated by precessing magnetization aligned with the edges. Our findings represent a crucial step forward in the design of nanoscale spin-wave sources for magnonic architectures and are also highly relevant to the understanding and interpretation of magnetization dynamics driven by spatially uniform magnetic fields in patterned magnetic samples.
Non-destructive measurement and monitoring of separation of charged particle micro-bunches
Authors: Zhang H. , Konoplev I. V. , Lancaster A. J. , Harrison H. , Doucas G. , Aryshev A. , Shevelev M. , Terunuma N. , Urakawa J.
Published: July 2017

Micro-bunched particle beams are used for a wide range of research including wakefield-based particle acceleration and tunable sources of radiation. In all applications, accurate and non-destructive monitoring of the bunch-to-bunch separation is required. With the development of femtosecond lasers, the generation of micro-bunched beams directly from a photocathode becomes routine; however, non-destructive monitoring of the separation is still a challenge. We present the results of proof-of-principle experiments conducted at the Laser Undulator Compact X-ray accelerator measuring the distance between micro-bunches via the amplitude modulation analysis of a monochromatic radiation signal. Good agreement with theoretical predictions is shown; limitations and further improvements are discussed.
Enhanced model accurately captures extremes in stock market performance
Authors: Bello Mark
Published: July 2017

Researchers find long-term stock market efficiency is the counterbalancing of short-term inefficiencies.
Global animal production and nitrogen and phosphorus flows
Authors: Liu Qian , Wang Jingmeng , Bai Zhaohai , Ma Lin , Oenema Oene
Published: July 2017

Animal production systems provide nutritious food for humans, income and survivability for numerous smallholder farms and transform residues to valuable products. However, animal production is implicated in human health issues (diet-related diseases, zoonosis, antimicrobial resistance) and environmental burdens (ammonia and greenhouse gas emissions, eutrophication of surface waters, biodiversity loss). This paper reviews changes in global animal production and associated nitrogen (N) and phosphorus (P) flows over the past 50 years, during which time total animal production roughly tripled. Cattle still dominate the world in terms of animal biomass, but the number and total production of pigs and poultry have increased faster. Animal production systems are highly diverse and respond to changes in markets. Specialised systems have become more dominant, especially in developed and rapidly developing countries. The annual production of N and P in manure is similar to the amounts of N and P in synthetic fertiliser produced annually, but manure nutrients are often not recycled effectively and used efficiently by plants. Nutrient losses greatly depend on the system, management and regulations. Nitrogen and P use efficiency (NUE and PUE respectively) at the animal level is in the range 5–45%, depending on animal category, feeding and management. NUE of mixed crop-animal systems may range from 5% to 65% depending on NUE at the animal level, and the utilisation of manure nitrogen and new nitrogen inputs. Potentially, values for PUE are higher than those for NUE. Solutions for improving NUE and PUE in animal production are based on a coherent set of activities in the whole chain of ‘feed production–animal production–manure management’. A high efficiency at the system level is achieved through combination of high NUE and PUE at the animal level and effective recycling and utilisation of manure N and P in crop production. Specific regional regulations (low-emission manure storage and application, proper application limits and timing) greatly contribute to high efficiency at a system level.
Coevolution of cultural intelligence, extended life history, sociality, and brain size in primates
Authors: Street Sally E. , Navarrete Ana F. , Reader Simon M. , Laland Kevin N.
Published: July 2017

Explanations for primate brain expansion and the evolution of human cognition and culture remain contentious despite extensive research. While multiple comparative analyses have investigated variation in brain size across primate species, very few have addressed why primates vary in how much they use social learning. Here, we evaluate the hypothesis that the enhanced reliance on socially transmitted behavior observed in some primates has coevolved with enlarged brains, complex sociality, and extended lifespans. Using recently developed phylogenetic comparative methods we show that, across primate species, a measure of social learning proclivity increases with absolute and relative brain volume, longevity (specifically reproductive lifespan), and social group size, correcting for research effort. We also confirm relationships of absolute and relative brain volume with longevity (both juvenile period and reproductive lifespan) and social group size, although longevity is generally the stronger predictor. Relationships between social learning, brain volume, and longevity remain when controlling for maternal investment and are therefore not simply explained as a by-product of the generally slower life history expected for larger brained species. Our findings suggest that both brain expansion and high reliance on culturally transmitted behavior coevolved with sociality and extended lifespan in primates. This coevolution is consistent with the hypothesis that the evolution of large brains, sociality, and long lifespans has promoted reliance on culture, with reliance on culture in turn driving further increases in brain volume, cognitive abilities, and lifespans in some primate lineages.