bluuebunny/crossref_metadata_2025 huggingface dataset:
Ergonomic Evaluation of Smart Navigation System for Riding on Motorcycle
Authors: Liu Po-Hsiang , Li Yong-Cheng , Tsai Yu-Jung
Published: September 2018

A smart navigation device could be provided to keep riders’ eyes safely on the road while riding on motorcycle. Present study surveyed the riding behaviors and examined the fifteen design factors about navigation device and determined the priority of each factor. Further, navigation device have been evaluated on road. A total of 550 questionnaires were dispatched, with a response rate of 89 % (n = 491). Results of factor analysis showed the six dimensions of prediction information, real-time information, brand and appearance, cost, functionality, efficacy and utility. Further, the highest priority design factors of smart navigation device are reminder for speeding camera, intersection name of next turn, distance of next turn, lane guide and map guide line. After navigation device have been evaluated on road, the smart device that effortlessly guides rider through the safest and most enjoyable riding routes with intuitive light patterns. Results of this study could provide the information for the design of the smart navigation device for riding on motorcycle.
None Operational Amplifier (OPA) Based: Design of Analogous Bandgap Reference Voltage
Authors: Chan Hao-Ping , Hung Yu-Cherng
Published: September 2018

By using 0.35-um CMOS process, this work achieves a design of analogous band-gap reference voltage circuit with low temperature coefficient. The proposed circuit operates at 3V and generates a reference current of 44 uA. The HSPICE simulation results show the temperature coefficient of this circuit is 23 ppm/°C at range of -10 °C to 100 °C, and the line regulation (the ratio of output current variation to supply voltage variation) is estimated as 1.95 uA/V from supply voltage variation of 3 V to 5 V. The experimental chip is fabricated and measured. The circuit provides adjustable capability for output voltage among temperature variation of -10 - 100 °C. The chip area is 534 × 695 um2. In this new design, the operational amplifier is not necessary. The chip design effort can be great reduced.
Design of a Low on Resistance High Voltage (120V) Novel 3D NLDMOS with Side Isolation Based on 0.35um BCD Process Technology
Authors: Yang Shao-Ming , Sheu Gene , Lee Tzu Chieh , Chien Ting Yao , Wu Chieh Chih , Lin Yun Jung
Published: September 2018

High performance power device is necessary for BCD power device. In this paper, we used 3D Synopsis TCAD simulation tool Sentaurus to develop 120V device and successfully simulated. We implemented in a conventional 0.35um BCDMOS process to present of a novel high side 120V LDMOS have reduced surface field (RESURF) and Liner p-top structure with side isolation technology. The device has been research to achieve a benchmark specific on-resistance of 189 mΩ-mm2 while maintaining horizontal breakdown voltage and vertical isolation voltage both to target breakdown voltage of 120V. In ESOA, we also proposed a better performance of both device without kirk effect.
120V Low Side LDMOS Device with Sided Isolation of 0.35μm CMOS Compatible Process
Authors: Deivasigamani Ravi , Sheu Gene , Aryadeep Chirag , Sai S. Krishna , Selvendran S. , Yang Shao-Ming
Published: September 2018

In this paper, a novel 120V multiple RESURF lateral double-diffused MOS (LDMOS) transistor with shallow trench isolation (STI) structure in low side is developed and successfully simulated. The proposed multiple RESURF LDMOS is able to achieve better ESOA performance while maintaining a benchmark specific on-resistance with breakdown voltage over 120 Volts. The key feature of this novel device is linear p-top rings which are located in the n-drift region. Optimization of p-top mask design and n-drift region concentration is performed in order to achieve the lowest on-resistance possible with the desired breakdown voltage.
Comparison of bulk FinFET and SOI FinFET
Authors: Chen Ying-Yu , Lin Yu-Hsien
Published: September 2018

In this study, we compare the differences and advantages between Bulk FinFET and SOI FinFET. The results are simulated by using the ISE TCAD software. By changing the parameters of the gate voltage, drain voltage and gate length to analysis which characteristic is better. Through the experiment results, we demonstrate that the SOI FinFET have the better characteristics than bulk FinFET[1].
A Quality Discriminaton within Ultra Violet Spectrum using Optical Sensor for Selected Commercial Oils
Authors: Ismail Khadijah , Abdul Razak Wardah
Published: September 2018

Nowadays ultra violet-visible (UV-Vis) spectrophotometers are widely used and is one of an important analytical instrument in modern day research. This work is conducted to determine oil quality discrimination of different selected oils using optical sensor, where the oil samples are analyzed within ultra violet (UV) spectrum, which ranges from 200nm to 400nm wavelengths. The oils extracted from five plants are analyzed based on the light absorption rate at different wavelengths. Different energy value is required for electron transition from lower level to the higher, due to different molecular structure of the main compound in the oil. The highest absorption rate at wavelength 393 nm is achieved from lemongrass oil, whereas the lowest absorption peak at 368 nm is observed from ginger oil.
A Novel Approach to Improve Quality Control by Comparing the Tagged Sequences of Product Traceability
Authors: Wang Jing-Doo
Published: September 2018

Quality control is an essential issue for manufacture, especially when the manufacture is towards intelligent manufacturing that is associated with “Internet of thing”(IOT) and “Artificial Intelligence”(AI) to speed up the rate of product line automatically nowadays. To monitor product quality automatically, it is necessary to collect and monitor the data generated by sensors, or to record parameters by machine operators, or to save the types (brands) of materials used when producing products. In this study, it is assumed that the sequences of the traceability of unqualified products are different from that of qualified ones, and these different values (or points) within the sequences result in these products qualified or unqualified. This approach extracts maximal repeats from the tagged sequences of product traceability, and meanwhile computes the class frequency distribution of these repeats, where the classes, e.g. “qualified” or “unqualified”, are derived from the tags. Instead of inspecting all of the sequences of product traceability aimlessly, quality control engineers can filter out those maximal repeats whose frequency distributions are unique to specific classes and then just check the corresponding processes of these repeats. However, from the practical point of view, it should be estimated as a big-data problem to extract these maximal repeats and meanwhile compute their corresponding class frequency distribution from a huge amount of tagged sequential data. To have this work practical, this study uses one previous work that is based on Hadoop MapReduce programming model. and has been applied for an U.S.A patent (US Patent App. 15/208,994). Therefore, it is expected to be able to handle a huge amount of sequences of product traceability. With this approach that can narrow down the range for identifying false points (processes) within product line, it is expected to improve quality control by comparing tagged sequences of product traceability in the future.
Early Failure in Medial Unicondylar Arthroplasty: Radiographic Analysis on the Importance of Joint Line Restoration
Authors: Lo Presti Mirco , Raspugli Giovanni Francesco , Reale Davide , Iacono Francesco , Zaffagnini Stefano , Filardo Giuseppe , Marcacci Maurilio
Published: September 2018

Survivorship of unicondylar knee arthroplasty (UKA) remains a drawback, especially compared with the outcome of total knee arthroplasty. This could be improved by identifying and correcting failure mechanisms. To this purpose, this study aimed at exploring failure modalities of UKA, with particular focus on the role of joint line (JL) position and alignment as variable to be optimized for a successful outcome. This study explored modes of failure in 266 medial UKAs. Radiological comparison was performed between 24 failures and 24 matched controls, to determine the importance of UKA positioning in terms of femorotibial angle (FTA), tibial plateau angle, and posterior tibial slope (PTS). Radiographic comparative analysis showed statistically significant differences in the failure group compared with the control group in terms of variation in FTA (p = 0.0222), PTS (p = 0.0025), and JL height (p = 0.0022). Variations not only in FTA but also PTS and JL height were correlated with failures observed in this series. Thus, based on the results of this study, it emerges that JL position should be carefully controlled in all planes while implanting a UKA. This is a Level III, case–control study.
Outcomes of Anterior Cruciate Ligament Reconstruction in Females Using Patellar–Tendon–Bone versus Hamstring Autografts: A Systematic Review and Meta-Analysis
Authors: Tan Si Heng Sharon , Lau Bernard Puang Huh , Krishna Lingaraj
Published: September 2018

The current review aims to compare the outcomes of anterior cruciate ligament (ACL) reconstruction in the female population after patellar–tendon–bone and hamstring grafts. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All original randomized controlled trials and prospective cohort studies that compared clinical outcomes after female ACL reconstruction using hamstring versus patellar–tendon–bone grafts were included. All clinical outcomes reported by three or more studies were included. Fifteen publications, with 948 female patients, were included. Most outcomes were reported to have no significant graft differences by all studies that reported the outcome. These included all the outcomes for objective knee scores (International Knee Documentation Committee [IKDC] objective knee score), neuromuscular testing (quadriceps strength, hamstring strength, and single hop test), graft rupture or failure, and subjective knee scores (Lysholm score and IKDC subjective knee score). The pivot shift test, flexion deficit, and presence of crepitus were also reported to have no significant graft differences by all studies. Some studies reported a significant difference in anteroposterior laxity (Lachman's test and instrumented laxity), range of motion deficits (extension deficit), and sports and activity level (Tegner score). However, these statistically significant differences were noted to be clinically insignificant due to the normal population variation or standard error of measurement of these tools of evaluation. Patients reconstructed with patellar-tendon–bone grafts have a higher risk of kneeling pain. There was no significant difference in the incidence of crepitus. Most of the outcomes following female ACL reconstructions showed no clinically and statistically significant difference when either patellar–tendon–bone or hamstring autograft was used. These included outcomes for anteroposterior laxity, objective knee scores, neuromuscular testing, graft rupture or failure, subjective knee scores, sports and activity level, and crepitus. This a level II study.
Note: Controlling the length of plasmonic tips obtained by pulsed electrochemical etching
Authors: Plathier J. , Pignolet A. , Ruediger A.
Published: September 2018

We present a method to control the length of plasmonic gold tips through pulsed electrochemical etching. This method uses a cut-off circuit to interrupt the etching when the desired length is achieved, paving the way to tune the plasmonic properties of these tips through their shape. The control of the tip length by monitoring the cell voltage is the result of a study of the etching dynamics. The resulting tips possess a low apex radius and a small opening angle, allowing for high spatial resolution both in topography and in near-field imaging. The plasmonic behavior was confirmed in tip-enhanced Raman spectroscopy.
The interaction of a walking droplet and a submerged pillar: From scattering to the logarithmic spiral
Authors: Harris Daniel M. , Brun P.-T. , Damiano Adam , Faria Luiz M. , Bush John W. M.
Published: September 2018

Millimetric droplets may walk across the surface of a vibrating fluid bath, propelled forward by their own guiding or “pilot” wave field. We here consider the interaction of such walking droplets with a submerged circular pillar. While simple scattering events are the norm, as the waves become more pronounced, the drop departs the pillar along a path corresponding to a logarithmic spiral. The system behavior is explored both experimentally and theoretically, using a reduced numerical model in which the pillar is simply treated as a region of decreased wave speed. A trajectory equation valid in the limit of weak droplet acceleration is used to infer an effective force due to the presence of the pillar, which is found to be a lift force proportional to the product of the drop’s walking speed and its instantaneous angular speed around the post. This system presents a macroscopic example of pilot-wave-mediated forces giving rise to apparent action at a distance.
Bouncing droplet dynamics above the Faraday threshold
Authors: Tambasco L. D. , Pilgram J. J. , Bush J. W. M.
Published: September 2018

We present the results of an experimental investigation of the dynamics of droplets bouncing on a vibrating fluid bath for forcing accelerations above the Faraday threshold. Two distinct fluid viscosity and vibrational frequency combinations (20 cS–80 Hz and 50 cS–50 Hz) are considered, and the dependence of the system behavior on drop size and vibrational acceleration is characterized. A number of new dynamical regimes are reported, including meandering, zig-zagging, erratic bouncing, coalescing, and trapped regimes. Particular attention is given to the regime in which droplets change direction erratically and exhibit a dynamics akin to Brownian motion. We demonstrate that the effective diffusivity increases with vibrational acceleration and decreases with drop size, as suggested by simple scaling arguments.
Hydrodynamic spin states
Authors: Oza Anand U. , Rosales Rodolfo R. , Bush John W. M.
Published: September 2018

We present the results of a theoretical investigation of hydrodynamic spin states, wherein a droplet walking on a vertically vibrating fluid bath executes orbital motion despite the absence of an applied external field. In this regime, the walker’s self-generated wave force is sufficiently strong to confine the walker to a circular orbit. We use an integro-differential trajectory equation for the droplet’s horizontal motion to specify the parameter regimes for which the innermost spin state can be stabilized. Stable spin states are shown to exhibit an analog of the Zeeman effect from quantum mechanics when they are placed in a rotating frame.
Fast-framing camera based observations of spheromak-like plasmoid collision and merging process using two magnetized coaxial plasma guns
Authors: Matsumoto T. , Roche T. , Allfrey I. , Gota H. , Asai T. , Edo T. , Hosozawa A. , Tanaka F. ,   TAE Team
Published: September 2018

We have been conducting compact toroid (CT) collision and merging experiments by using two magnetized coaxial plasma guns. As is well known, an actual CT/plasmoid moves macroscopically in a confining magnetic field. Therefore, three-dimensional measurements are important in understanding the behavior of the CTs. To observe the macroscopic process, we adopted a fast-framing camera (ULTRA Cam HS-106E) developed by NAC Image Technology. The characteristics of this camera are as follows: a CCD color sensor, capable of capturing 120 images during one sequence with a frame rate of up to 1.25 MHz. Using this camera, we captured the global motion of a CT inside the magnetic field and the collision of two CTs at the mid-plane of the experimental device. Additionally, by using a color sensor, we captured the global change in the plasma emission of visible light during the CT collision/merging process. As a result of these measurements, we determined the CT’s global motion and the changes in the CT’s shape and visible emission. The detailed system setup and experimental results are presented and discussed.
A new generation of effective core potentials from correlated calculations: 2nd row elements
Authors: Bennett M. Chandler , Wang Guangming , Annaberdiyev Abdulgani , Melton Cody A. , Shulenburger Luke , Mitas Lubos
Published: September 2018

Very recently, we have introduced correlation consistent effective core potentials (ccECPs) derived from many-body approaches with the main target being their use in explicitly correlated methods, while still usable in mainstream approaches. The ccECPs are based on reproducing excitation energies for a subset of valence states, namely, achieving near-isospectrality between the original and pseudo Hamiltonians. In addition, binding curves of dimer molecules were used for refinement and overall improvement of transferability over a range of bond lengths. Here we apply similar ideas to the 2nd row elements and study several aspects of the constructions in order to find the high accuracy solutions within the chosen ccECP forms with 3s, 3p valence space (Ne-core). Our new constructions exhibit accurate low-lying atomic excitations and equilibrium molecular bonds (on average within ≈0.03 eV and 3 mÅ); however, the errors for Al and Si oxide molecules at short bond lengths are notably larger for both ours and existing effective core potentials. Assuming this limitation, our ccECPs show a systematic balance between the criteria of atomic spectra accuracy and transferability for molecular bonds. In order to provide another option with much higher uniform accuracy, we also construct He-core ccECPs for the whole 2nd row with typical discrepancies of ≈0.01 eV or smaller.
Millimeter-wave interferometry and far-forward scattering for density fluctuation measurements on LTX-β
Authors: Kubota S. , Majeski R. , Boyle D. P. , Kaita R. , Kozub T. , Lantsov R. , Merino E. , Nguyen X. V. , Peebles W. A. , Rhodes T. L.
Published: September 2018

The λ ≈ 1 mm (f = 288 GHz) interferometer for the Lithium Tokamak Experiment-β (LTX-β) will use a chirped-frequency source and a centerstack-mounted retro-reflector mirror to provide electron line density measurements along a single radial chord at the midplane. The interferometer is unique in the use of a single source (narrow-band chirped-frequency interferometry) and a single beam splitter for separating and recombining the probe and reference beams. The current work provides a documentation of the interferometry hardware and evaluates the capabilities of the system as a far-forward collective scattering diagnostic. As such, the current optical setup is estimated to have a detection range of 0.4 ≲ k⊥ ≲ 1.7 cm−1, while an improved layout will extend the upper k⊥ limit to ∼3 cm−1. Measurements with the diagnostic on LTX are presented, showing interferometry results and scattered signal data. These diagnostics are expected to provide routine measurements on LTX-β for high frequency coherent density oscillations (e.g., Alfvénic modes during neutral beam injection) as well as for broadband turbulence.
Ultra-low-density silver aerogels via freeze-substitution
Authors: Fears Tyler M. , Hammons Joshua A. , Sain John D. , Nielsen Michael H. , Braun Tom , Kucheyev Sergei O.
Published: September 2018

Herein is reported a method for fabricating <10 mg/cm3 silver aerogels via the freeze casting of aqueous nanowire suspensions followed by freeze substitution and supercritical drying. This method overcomes the limitations of traditional freeze drying and yields highly uniform, crack-free monoliths that undergo no measurable shrinkage with excellent mold reproduction. Significantly, freeze substitution enables the use of high concentrations of cryoprotectants to control the freezing process and, hence, the pore architecture of the resulting aerogels. Due to its physical nature, this method is applicable to the fabrication of materials with a broad range of compositions.
Direct simulation of sound generation by a two-dimensional flow past a wedge
Authors: Mahato Bikash , Ganta Naveen , Bhumkar Yogesh G.
Published: September 2018

Direct simulations of sound generation due to two-dimensional, unsteady, laminar flow past a wedge at several angles of incidence have been performed using a highly accurate, physical dispersion relation preserving scheme. We have considered a uniform flow past a wedge at a Mach number of M = 0.2 and a Reynolds number of Re = 100, at thirteen different angles of incidence 0° ≤ α ≤ 60°. Results show that the vortex shedding phenomena which in turn strongly depend on the angle of incidence are responsible for triggering negative and positive pressure pulses. We have in particular focused our attention on a special case α = 30° where the mean drag attains a lowest value among all angle of incidence cases and also reports a highest root mean square value for the lift coefficient. We have closely related the effects of the fluctuations in flow field parameters on the frequency and amplitudes of generated sound waves. The generated sound field displays dipolar nature. The lift dipole contributes more to the sound field as compared to the drag dipole. The dominating nature of the lift dipole has been confirmed by the proper orthogonal decomposition of the disturbance pressure field. Using Doak’s decomposition technique, the instantaneous flow field for different cases is decomposed into acoustic, entropic, and hydrodynamic modes. Doak’s decomposition further confirms that the amplitude and the frequency associated with lift and drag coefficient fluctuations characterize sound field generation and its propagation. It has been found that the generated sound field is greatly enhanced as α varies from 30° to 60°.
Peculiarities of the current-voltage and capacitance-voltage characteristics of plasma etched GaN and their relevance to n-GaN Schottky photodetectors
Authors: Chatterjee Abhishek , Agnihotri V. K. , Khamari Shailesh K. , Porwal S. , Bose A. , Joshi S. C. , Sharma T. K.
Published: September 2018

The impact of reactive ion etching (RIE) induced damage on the optoelectronic properties of GaN epitaxial layers and the photoresponse of Schottky detectors is investigated. Plasma induced surface damage in epitaxial layers is noticed which leads to a significant reduction of the intensity of the photoluminescence signal and also the photoresponse of detector devices post dry etching process. Electrical characterization of Au/Ni/GaN Schottky diodes along with secondary ion mass spectroscopy results indicate that the ion bombardment induced damage is mostly confined close to the surface of the GaN layer. It is found that the current-voltage characteristics of Schottky contacts on pristine n-GaN layers can be understood by considering a model based on the thermionic emission of carriers across the junction. However, the same is not possible in the case of plasma etched samples where the involvement of the thermionic field emission of carriers is essential. It is proposed that the RIE process leads to the generation of nitrogen vacancies in strongly localized domains near the surface. Such vacancies act as shallow donors shifting the Fermi level into the conduction band, thus enabling the tunnelling of carriers across the junction. However, this is not evident in capacitance-voltage characteristics since the damage is much prior to the depletion edge and is confined to extremely small domains. A method for the recovery of dry etch induced damage through O2 plasma treatment is demonstrated which is found to be very effective in improving the post-etch surface morphology and also the optoelectronic properties of etched GaN epitaxial layers. The spectral response of the Schottky photodetector is seen to degrade by 90% due to the plasma etching process. However, the same can be recovered along with an enhancement of the deep ultraviolet response of the detector after O2 plasma treatment of etched layers within the RIE chamber. The understanding developed here is crucial for the optimization of the RIE process and is found to be very helpful in recovery of damage caused by the dry etching process.
Behavior of numerical error in pore-scale lattice Boltzmann simulations with simple bounce-back rule: Analysis and highly accurate extrapolation
Authors: Khirevich Siarhei , Patzek Tadeusz W.
Published: September 2018

We perform the viscosity-independent Stokes flow simulations in regular sphere packings using the two-relaxation-times (TRT) lattice Boltzmann method (LBM) with the simple bounce-back (BB) rule. Our special discretization procedure reduces the scatter in integral quantities, such as drag force, and quantifies the solution convergence error. We assume transition to linear (−1) convergence rate for different sets of TRT parameters and use this assumption to provide a simple extrapolation scheme. After establishing the accurate reference values of drag for a wide range of porosities, 0.26–0.78, we show a ten-fold decrease in the drag error using the suggested extrapolations. This error decrease allows the simple LBM/BB scheme to reach an accuracy of the high-order interpolated boundary schemes. The suggested extrapolation approach is straightforward to apply in porous media, whose pore space can be discretized at several resolutions.
Reflectance determination of optical spectral emissivity of metal surfaces at ambient conditions
Authors: Hartsfield T. M. , Iverson A. J. , Baldwin J. K.
Published: September 2018

Optical pyrometry requires knowledge of both spectral radiance and spectral emissivity to accurately measure temperature. No reliable compendium of spectral emissivity data currently exists for common metals in the optical and near-infrared spectral regions where pyrometry is typically performed. Here, we measure the spectral reflectivity of numerous common metals, with known surface finishes, between 400 and 1100 nm. The measurements are carried out under ambient conditions, near 300 K at an atmospheric pressure of ∼0.78 bar. We then calculate the emissivity as a function of the wavelength for each sample. We define and use the illumination and collection geometries most practical for applying these measurements to radiometric thermometry. We also examine the effect of surface finish upon the relative spectral emissivity of a given material and find qualitative guidelines for predicting the increase in emissivity with increasing surface roughness. These measurements can both improve the accuracy and precision of optical pyrometry and provide the necessary reference value for converting emerging diagnostic measurements of relative spectral emissivity under extreme dynamic conditions into absolute dynamic spectral emissivity.
Vacuum ultraviolet photodissociation dynamics of N2O via the C1Π state: The N(2Dj=5/2, 3/2) + NO(X2Π) product channels
Authors: Yu Shengrui , Yuan Daofu , Chen Wentao , Xie Ting , Zhou Jiami , Wang Tao , Chen Zhichao , Yuan Kaijun , Yang Xueming , Wang Xingan
Published: September 2018

We study the vacuum ultraviolet photodissociation dynamics of N2O via the C1Π state by using the time-sliced velocity map ion imaging technique. Images of N(2Dj=5/2, 3/2) products from the N atom elimination channels were acquired at a set of photolysis wavelengths from 142.55 to 148.19 nm. Vibrational states of the NO(X2Π) co-fragments were partially resolved in experimental images. From these images, the product total kinetic energy release distributions (TKERs), branching ratios of the vibrational states of NO(X2Π) co-fragments, and the vibrational state specific angular anisotropy parameters (β) have been determined. Notable features were found in the experimental results: the TKERs show that the NO(X2Π) co-fragments are highly vibrationally excited. For the highly vibrationally excited state of NO(X2Π), a bimodal rotational structure is found at all the studied photolysis wavelengths. Furthermore, the vibrational state specific β values of both spin-orbit channels (j = 3/2, 5/2) clearly show a monotonic decrease as the vibrational quantum number of NO(X2Π) increases. These observations suggest that multiple dissociation pathways play a role in the formation of the N(2Dj=5/2, 3/2) + NO(X2Π) products: one corresponds to a fast dissociation pathway through the linear state (the C1Π state) following the initial excitation to a slightly bent geometry in the vicinity of the linear C1Π configuration, leading to the low rotationally excited components with relatively large β values; the other corresponds to a relatively slow dissociation pathway through the bent C(31A′) or C(31A″) state, leading to moderately rotationally excited NO(X2Π) products with smaller β values.
Multiband light emission and nanoscale chemical analyses of carbonized fumed silica
Authors: Vasin A. V. , Kysil D. V. , Lajaunie L. , Rudko G. Yu. , Lysenko V. S. , Sevostianov S. V. , Tertykh V. A. , Piryatinski Yu. P. , Cannas M. , Vaccaro L. , Arenal R. , Nazarov A. N.
Published: September 2018

Fumed silica with a specific area of 295 m2/g was carbonized by successive phenyltrimethoxysilane treatments followed by annealing in inert atmosphere up to 650 °C. Emission, excitation, kinetics, and photo-induced bleaching effects were investigated by steady state and time-resolved photoluminescence spectroscopies. The local chemistry was also studied by infrared transmission spectroscopy. Strong ultraviolet and visible photoluminescence was observed in the samples after the chemical treatments/modifications and thermal annealing. It has been shown that ultraviolet photoluminescence in chemically modified fumed silica is associated with phenyl groups, while near ultraviolet and visible emission in annealed samples originated from inorganic pyrolytic carbon precipitates dispersed in the silica host matrix. Two types of emission bands were identified as a function of the annealing temperature: one is in the near UV and the other is in the visible range. Based on the emission/excitation analysis of these two bands, as well as on correlations with the synthesis conditions, a structural-energy concept of light-emitting centers has been proposed. According to this model, the light-emitting centers are associated with carbon clusters that can be bonded or adsorbed on the silica surface. This has been validated by a detailed (S)TEM-electron energy-loss spectroscopy study, confirming the inhomogeneous distribution of nanoscale carbon precipitates at the surface of the silica nanoparticles. These carbon precipitates are mostly amorphous although they possess some degree of graphitization and local order. Finally, the fraction of sp2 carbon in these nanoclusters has been estimated to be close to 80%.
Relating Franck-Condon blockade to redox chemistry in the single-particle picture
Authors: Bevan Kirk H. , Roy-Gobeil Antoine , Miyahara Yoichi , Grutter Peter
Published: September 2018

In this work, we explore Franck-Condon blockade in the “redox limit,” where nuclear relaxation processes occur much faster than the rate of electron transfer. To this end, the quantized rate expressions for electron transfer are recast in terms of a quantized redox density of states (DOS) within a single phonon mode model. In the high temperature regime, this single-particle picture formulation of electron transfer is shown to agree well with the semi-classical rate and DOS expressions developed by Gerischer and Hopfield. Upon incorporation into a two electrode formulation, utilizing the master equation approach, the low temperature quantized conductance features of Franck-Condon blockade are reproduced. Moreover, at sufficiently large reorganization energies, it is argued that Franck-Condon blockade should also be observable in room temperature systems. In general, this work aims to further bridge descriptions of electron transfer and transport in the single-particle picture.
Melts of CrCoNi-based high-entropy alloys: Atomic diffusion and electronic/atomic structure from ab initio simulation
Authors: Ding Jun , Asta Mark , Ritchie Robert O.
Published: September 2018

High-entropy alloys (HEAs) are an emerging class of advanced structural alloys under extensive research; yet, the properties of the liquid states of these materials, which are relevant to their processing, have been far less explored. In this work, we utilize ab initio molecular dynamics simulations to investigate the melt properties of a representative HEA—the Cantor alloy—and its derivatives: CrMnFeCoNi, CrFeCoNi, and CrCoNi. The atomic dynamics of these melts at various temperatures are investigated, specifically to analyze their electronic and atomic structures, including charge transfer, pair distribution functions, and short-range order. Results are compared with existing information for the liquids of metallic glasses, which also typically contain multiple principal elements, but retain the amorphous state under moderate to fast cooling rates. The present results provide insights into the structural and bonding factors favoring solidification to single-phase solid solutions in HEAs.
Predictive modeling of misfit dislocation induced strain relaxation effect on self-rolling of strain-engineered nanomembranes
Authors: Chen Cheng , Song Pengfei , Meng Fanchao , Ou Pengfei , Liu Xinyu , Song Jun
Published: September 2018

Combining atomistic simulations and continuum modeling, the effects of misfit dislocations on strain relaxation and subsequently self-rolling of strain-engineered nanomembranes have been investigated. Two representative material systems including (GaN/In0.5Ga0.5N) of wurtzite lattice and II–VI materials (CdTe/CdTe0.5S0.5) of zinc-blend lattice were considered. The atomistic characteristics of dislocation and the resulting lattice distorting were first determined by generalized-stacking-fault energy profile and disregistry function obtained through Peierls-Nabarro model. Those properties were then used to calculate the accurate mismatch strain of those nanomembranes with the presence of dislocations, and as inputs into von-Karman shell theory to quantitatively evaluate the effects on self-rolling curvature and anisotropy. The theoretical results were further confirmed by atomistic simulations of different crystal geometries and dislocation configurations. Our results provide essential theoretical insights towards prediction and design of rollup configurations for strain-engineered nanomembranes containing crystalline defects.
GaN surface as the source of non-radiative defects in InGaN/GaN quantum wells
Authors: Haller C. , Carlin J.-F. , Jacopin G. , Liu W. , Martin D. , Butté R. , Grandjean N.
Published: September 2018

Blue light-emitting diodes based on III-nitride semiconductors are nowadays widely used for solid-state lighting. They exhibit impressive figures of merit like an internal quantum efficiency close to 100%. This value is intriguing when considering the high dislocation density running throughout the InGaN/GaN quantum well (QW) active region. This striking feature is currently ascribed to carrier localization occurring in the InGaN alloy, which hinders their diffusion toward dislocations. However, it was recently reported that another source of defects, disconnected from dislocations, dramatically decreases the radiative efficiency of InGaN/GaN QWs. Those defects, present at the surface, are usually trapped in an InGaN underlayer (UL), which is grown before the QW active region. To get insight into the trapping mechanism, we varied the UL thickness, In content, and materials system (InGaN or InAlN) and studied the photoluminescence decay time at 300 K of a single InGaN/GaN QW. Our data demonstrate that defects are incorporated proportionally to the indium content in the UL. In addition, we show that those defects are created during the high-temperature growth of GaN and that they segregate at the surface even at low-temperature. Eventually, we propose an intrinsic origin for these surface defects.
A neutral wind instrument for nano-satellite platforms
Authors: Kordella L. J. , Earle G. D. , Roth G. , Noel S. , Robertson R. V. , Davidson R. L. , Holland C. E. , Garg V.
Published: September 2018

Here we describe the first neutral wind sensor developed specifically for use on resource limited nano-satellite platforms. The instrument is a next generation redesign of the ram wind sensor flown on the Communications/Navigation Outage Forecasting System satellite for measurements of neutral velocity, temperature, and composition. Results of subsystem tests in vacuum conditions show low-power operation, promising design, and good resolution of measured parameters over the operational pressure and energy ranges expected in the low Earth orbit environment.
Aggregation recovers developmental plasticity in mouse polyploid embryos
Authors: Imai Hiroyuki , Fujii Wataru , Kusakabe Ken Takeshi , Kiso Yasuo , Kano Kiyoshi
Published: September 2018

Tetraploid embryos normally develop into blastocysts and embryonic stem cells can be established from tetraploid blastocysts in mice. Thus, polyploidisation does not seem to be so harmful during preimplantation development. However, the mechanisms by which early mammalian development accepts polyploidisation are poorly understood. In this study, we aimed to elucidate the effect of polyploidisation on early mammalian development and to further comprehend its tolerance using hyperpolyploid embryos produced by repetitive whole genome duplication. We successfully established several types of polyploid embryos (tetraploid, octaploid and hexadecaploid) and studied their developmental potential invitro. We demonstrated that all types of these polyploid embryos maintained the ability to develop to the blastocyst stage, which implies that mammalian cells might have basic cellular functions in implanted embryos, despite polyploidisation. However, the inner cell mass was absent in hexadecaploid blastocysts. To complement the total number of cells in blastocysts, a fused hexadecaploid embryo was produced by aggregating several hexadecaploid embryos. The results indicated that the fused hexadecaploid embryo finally recovered pluripotent cells in the blastocyst. Thus, our findings suggest that early mammalian embryos may have the tolerance and higher plasticity to adapt to hyperpolyploidisation for blastocyst formation, despite intense alteration of the genome volume.
Improving mesocarnivore detectability with lures in camera-trapping studies
Authors: Ferreras Pablo , Díaz-Ruiz Francisco , Monterroso Pedro
Published: September 2018

Context
Camera trapping is commonly employed for studying carnivores because it provides better data than do other methods, and with lower costs. Increasing the probability of detecting the target species can reduce parameter uncertainty and survey effort required to estimate density and occurrence. Different methods, including attractants and baits, can be used to increase detectability. However, their efficacy has rarely been quantitatively assessed.

Aims
To quantify the efficacy of scent and bait attractants to increase the detection probability of mesocarnivores by camera trapping.

Methods
We tested two scent lures, valerian extract (Val) and lynx urine (LU), their combination (Val–LU), and a non-reward bait (i.e. not accessible to the animal), raw chicken, as carnivore attractants in two protected areas of central Spain. We used camera-trapping records under an occupancy-modelling framework to estimate attractant-specific detection probabilities for six mesocarnivore species, and quantified their effects by comparing these estimates with the baseline (i.e. no attractant) detectability.

Key results
The weekly detection probability of four mesocarnivore species (red fox, Vulpes vulpes, stone marten, Martes foina, common genet, Genetta genetta, and Eurasian badger, Meles meles) significantly increased when Val–LU (between 0.11 ± 0.07 and 0.67 ± 0.05) or chicken (between 0.31 ± 0.02 and 0.77 ± 0.22) were used as attractant, when compared with baseline detectability (between 0.01 ± 0.02 and 0.29 ± 0.05). Although rarely, wildcats (Felis silvestris) were mostly detected with Val–LU. The probability of detecting a species after k sampling occasions (7 days each) where it was present was highly improved with both Val–LU and chicken for all species (e.g. from 0.20 to 0.98 after four sampling occasions with chicken for the stone marten). Both attractants reduced the sampling time required to ascertain that a species was absent to between 42% and 15% of baseline values.

Conclusions
The tested attractants greatly improved the detectability of most Iberian mesocarnivores. Although chicken was preferable for some species such as stone marten, Val–LU is most efficient for detecting the whole mesocarnivore community, including rare species such as wildcats.

Implications
Attractant selection in studies using non-invasive detection methods must be supported by quantitative assessment of the detection probability associated to each attractant. Researchers must choose those attractants best fitting target species and study aims.
Functional diversification of the NleG effector family in enterohemorrhagic
Escherichia coli
Authors: Valleau Dylan , Little Dustin J. , Borek Dominika , Skarina Tatiana , Quaile Andrew T. , Di Leo Rosa , Houliston Scott , Lemak Alexander , Arrowsmith Cheryl H. , Coombes Brian K. , Savchenko Alexei
Published: September 2018

The pathogenic strategy of
Escherichia coli
and many other gram-negative pathogens relies on the translocation of a specific set of proteins, called effectors, into the eukaryotic host cell during infection. These effectors act in concert to modulate host cell processes in favor of the invading pathogen. Injected by the type III secretion system (T3SS), the effector arsenal of enterohemorrhagic
E. coli
(EHEC) O157:H7 features at least eight individual NleG effectors, which are also found across diverse attaching and effacing pathogens. NleG effectors share a conserved C-terminal U-box E3 ubiquitin ligase domain that engages with host ubiquitination machinery. However, their specific functions and ubiquitination targets have remained uncharacterized. Here, we identify host proteins targeted for ubiquitination-mediated degradation by two EHEC NleG family members, NleG5-1 and NleG2-3. NleG5-1 localizes to the host cell nucleus and targets the MED15 subunit of the Mediator complex, while NleG2-3 resides in the host cytosol and triggers degradation of Hexokinase-2 and SNAP29. Our structural studies of NleG5-1 reveal a distinct N-terminal α/β domain that is responsible for interacting with host protein targets. The core of this domain is conserved across the NleG family, suggesting this domain is present in functionally distinct NleG effectors, which evolved diversified surface residues to interact with specific host proteins. This is a demonstration of the functional diversification and the range of host proteins targeted by the most expanded effector family in the pathogenic arsenal of
E. coli
.
Developmental stage-specific proliferation and retinoblastoma genesis in RB-deficient human but not mouse cone precursors
Authors: Singh Hardeep P. , Wang Sijia , Stachelek Kevin , Lee Sunhye , Reid Mark W. , Thornton Matthew E. , Craft Cheryl Mae , Grubbs Brendan H. , Cobrinik David
Published: September 2018

Significance

Retinoblastoma is a childhood tumor that forms in response to mutations in the
RB1
gene and loss of functional RB protein. Prior studies suggested that retinoblastomas arise from cone photoreceptor precursors, whereas mouse models yield tumors deriving from other retinal cell types and lacking human retinoblastoma features. We show that in cultured human retinae, retinoblastomas initiate from RB-depleted cone precursors that are in a specific maturation state and form premalignant retinomas prior to retinoblastoma lesions, as is believed to occur in retinoblastoma patients. In contrast, Rb-deficient mouse cone precursors of similar maturation state and supplemented with human cone precursor-specific oncoproteins fail to proliferate. Thus, human species-specific developmental features underlie retinoblastoma genesis and may challenge the production of accurate retinoblastoma models.
High-resolution structures of HIV-1 Gag cleavage mutants determine structural switch for virus maturation
Authors: Mattei Simone , Tan Aaron , Glass Bärbel , Müller Barbara , Kräusslich Hans-Georg , Briggs John A. G.
Published: September 2018

HIV-1 maturation occurs via multiple proteolytic cleavages of the Gag polyprotein, causing rearrangement of the virus particle required for infectivity. Cleavage results in beta-hairpin formation at the N terminus of the CA (capsid) protein and loss of a six-helix bundle formed by the C terminus of CA and the neighboring SP1 peptide. How individual cleavages contribute to changes in protein structure and interactions, and how the mature, conical capsid forms, are poorly understood. Here, we employed cryoelectron tomography to determine morphology and high-resolution CA lattice structures for HIV-1 derivatives in which Gag cleavage sites are mutated. These analyses prompt us to revise current models for the crucial maturation switch. Unlike previously proposed, cleavage on either terminus of CA was sufficient, in principle, for lattice maturation, while complete processing was needed for conical capsid formation. We conclude that destabilization of the six-helix bundle, rather than beta-hairpin formation, represents the main determinant of structural maturation.
Interleukin-22 promotes phagolysosomal fusion to induce protection against
Salmonella enterica
Typhimurium in human epithelial cells
Authors: Forbester Jessica L. , Lees Emily A. , Goulding David , Forrest Sally , Yeung Amy , Speak Anneliese , Clare Simon , Coomber Eve L. , Mukhopadhyay Subhankar , Kraiczy Judith , Schreiber Fernanda , Lawley Trevor D. , Hancock Robert E. W. , Uhlig Holm H. , Zilbauer Matthias , Powrie Fiona , Dougan Gordon
Published: September 2018

Intestinal epithelial cells (IECs) play a key role in regulating immune responses and controlling infection. However, the direct role of IECs in restricting pathogens remains incompletely understood. Here, we provide evidence that IL-22 primed intestinal organoids derived from healthy human induced pluripotent stem cells (hIPSCs) to restrict
Salmonella enterica
serovar Typhimurium SL1344 infection. A combination of transcriptomics, bacterial invasion assays, and imaging suggests that IL-22–induced antimicrobial activity is driven by increased phagolysosomal fusion in IL-22–pretreated cells. The antimicrobial phenotype was absent in hIPSCs derived from a patient harboring a homozygous mutation in the
IL10RB
gene that inactivates the IL-22 receptor but was restored by genetically complementing the IL10RB deficiency. This study highlights a mechanism through which the IL-22 pathway facilitates the human intestinal epithelium to control microbial infection.
The exquisitely cooperative nature of Orai1 channel activation
Authors: Yeung Priscilla See-Wai , Prakriya Murali
Published: September 2018

Yeung and Prakriya highlight new research showing that STIM1 must bind to all six Orai1 subunits to effectively activate the channel.