bluuebunny/crossref_metadata_2025 huggingface dataset:
An efficient proline-based homogeneous organocatalyst with recyclability
Authors: Li Qiang , Li Yuan , Wang Jingdong , Lin Yingjie , Wei Zhonglin , Duan Haifeng , Yang Qingbiao , Bai Fuquan , Li Yaoxian
Published: December 2017

A homogeneous organocatalyst for asymmetric reduction of imines can be reused for several cycles through a self-assembly method using MNPs.
Modelling the surface of amorphous dehydroxylated silica: the influence of the potential on the nature and density of defects
Authors: Halbert Stéphanie , Ispas Simona , Raynaud Christophe , Eisenstein Odile
Published: December 2017

The nature and density of defects on the amorphous dehydroxylated silica surface are studied by molecular dynamics for information on the silanol groups of pretreated silica.
End-on cyanate or end-to-end thiocyanate bridged dinuclear copper(ii) complexes with a tridentate Schiff base blocking ligand: synthesis, structure and magnetic studies
Authors: Khan Samim , Sproules Stephen , Natrajan Louise S. , Harms Klaus , Chattopadhyay Shouvik
Published: December 2017

Two new dinuclear Schiff base copper(ii) complexes have been synthesized and characterized. Copper(ii) centres are ferromagnetically coupled in1and antiferromagnetically coupled in2.
One-step eco-friendly approach for the fabrication of synergistically engineered fluorescent copper nanoclusters: sensing of Hg2+ ion and cellular uptake and bioimaging properties
Authors: Bhamore Jigna R. , Deshmukh Balaji , Haran Varun , Jha Sanjay , Singhal Rakesh Kumar , Lenka Nibedita , Kailasa Suresh Kumar , Murthy Z. V. P.
Published: December 2017

Schematic illustration for one-step green synthetic approach for fabrication of synergistically engineered CuNCs.
Lighting retrofit and maintenance models with decay and adaptive control
Authors: Wu Zhou , Zhao Kai , Xia Xiaohua
Published: December 2017

In lighting retrofit projects, a lamp population is subject to decay, which results in significantly deteriorated energy efficiency (EE) and reduced cost saving. Incremental retrofit and maintenance are studied to overcome the decay in the population, so that EE performance can be sustained. Current models of natural decay cannot reflect the interactive dynamics of incremental retrofit and maintenance, so a new decay model is proposed for these interventions. Using a control approach, a multiple‐input and multiple‐output state equation is formulated. Adaptive control laws are designed to cope with unknown parameters of the proposed model, and to achieve stable performance improvement. This new model is verified, based on empirical data, and the results of adaptive control indicate that the number of working lamps can be maintained as a required value.
Hybrid image denoising method based on non‐subsampled contourlet transform and bandelet transform
Authors: Wang Xiaokai , Chen Wenchao , Gao Jinghuai , Wang Chao
Published: December 2017

The second generation bandelet transform uses the two‐dimensional (2D) separable wavelet transform to improve its image denoising and compression performance. However, the 2D separable wavelet transform is not a shift‐invariant transform and therefore cannot capture geometric information well. The authors propose a hybrid image denoising method in which the 2D separable wavelet transform in the second generation bandelet transform is replaced with the non‐subsampled contourlet transform. The results of the application of the proposed method to several greyscale and colour benchmark images contaminated with various levels of Gaussian white noise and Poisson noise indicate that the proposed method has good peak signal‐to‐noise ratio and visual quality performance.
Improved power allocation strategy of hybrid energy storage system in islanding DC micro‐grid
Authors: Chang Xiaoyong , Chen Fufeng , Li Yuping , Wang Yuting , Xu Chengji
Published: December 2017

In this study, the coordinated control method of a hybrid energy storage system (HESS) operated in an islanding DC micro‐grid (MG) is researched, based on which an improved power allocation strategy is proposed. In the proposed control strategy, the supercapacitor in the HESS is under voltage–power droop control to regulate the DC bus voltage directly. The battery in the HESS is controlled based on the droop characteristic of the DC bus voltage and is responsible for maintaining the state‐of‐charge (SOC) of the supercapacitor under control and compensating the instantaneous power fluctuations of the DC MG. A model of a simplified island‐mode DC MG is set up on the MATLAB/Simulink platform to verify the effectiveness of the presented control strategy. As a result, the transient response capability of the DC bus voltage is well guaranteed, and the current of the battery is efficaciously smoothed. The proposed control strategy is realised based on local information, and only the DC bus voltage is needed, which makes it convenient for application in reality.
Improvement of HVDC commutation failure response based on compound phase‐shifting control
Authors: Wang Shijia , Lu Shaoqi , Hou Yuqiang , Liu Fusuo , Xu Zheng
Published: December 2017

At present, the main control strategies for HVDC projects are derived from the ABB strategy and the SIEMENS strategy. In this paper, the difference between the two strategies in dealing with the inverter side ac fault is firstly analysed. It is pointed out that commutation failure (CF) with the SIEMENS strategy lasts longer than that with the ABB strategy, for the reason that the SIEMENS strategy still relies on PI regulation during the fault period and its response speed is relatively slow compared to the decreasing rate of the extinction angle. Then, a compound phase‐shifting control is proposed for the SIEMENS strategy, including control considering the rising rate and magnitude of dc current as well as control considering both unbalance and magnitude of ac voltage. The simulation results show that the application of the compound phase‐shifting control contributes to shortening the duration of CF, as well as improving power recovery and system response after fault cleared.
Output power smoothing of grid‐connected permanent‐magnet synchronous generator driven directly by variable speed wind turbine: a review
Authors: Qais Mohammed H. , Hasanien Hany M. , Alghuwainem Saad
Published: December 2017

The output power of wind farms is fluctuating as a result of the wind speed variation. These power fluctuations disturb the quality of voltage and frequency of the grid. The fluctuated power can be smoothed via many methods such as controlling the pitch angle of blades, the rotor inertia, and using the energy storage systems (ESSs). These ESSs are mostly installed in the renewable energy for load levelling with cost limitations. Owing to the high cost of ESSs, it is required to utilise and enhance different power control techniques. This study introduces different and recent proposed methods and enhancements to smoothen the output power of permanent‐magnet synchronous generator driven directly (gearless) by a variable‐speed wind turbine. Fuzzy logic control, sliding mode control, and evolutionary algorithms are used to enhance the control performance of pitch angle, machine‐side converter, and DC–DC converter of ESS.
Application of multi‐criteria decision analysis tool for design of a sustainable micro‐grid for a remote village in the Himalayas
Authors: Kumar Abhishek , Sah Bikash , Deng Yan , He Xiangning , Kumar Praveen , Bansal Ramesh C.
Published: December 2017

Decision analysis tool is utilised for the design and analysis of a microgrid with a perspective of sustainable development for a remote location in the hilly terrain of Himalayas. The microgrid design is based on the locally available energy resources, such as solar, wind, running water streams to meet the electrical load demand. The village selected has no access to electricity till date. A door‐to‐door survey is conducted to project the current and future load demand of the community. The complexity in designing sustainable energy system due to the inclusion of multiple criteria with multiple objectives and scenarios has increased to a great extent. Involvement of multiple stakeholders with differing views and various factors such as social, technical, environmental, economic and political/institutional, makes the process more tedious. For a successful design of the microgrid for such locations, a synergy needs to exist between differing viewpoints of stakeholder when multiple criteria with various scenarios are considered. Multiple criteria decision analysis tools are best suitable for such scenarios especially for energy planning based on renewable energy technologies. The process outlined in this paper will be helpful for successful design of sustainable microgrids for unelectrified and rural location in developing nations.
Dual Iminium- and Lewis Base Catalyzed Morita–Baylis–Hillman Reaction on Cyclopent-2-enone
Authors: Trabocchi Andrea , Innocenti Riccardo , Menchi Gloria
Published: December 2017

The application of iminium catalysis to the challenging Morita–Baylis–Hillman reaction on cyclopenten-2-one leads to the corresponding allylic alcohols in excellent yields. Experimental evidence shows that secondary amines act as co-catalysts activating the enone moiety towards the nucleophilic attack at the β-position by DABCO as the Lewis base catalyst, resulting in an augmented nucleophilic character towards the reaction with aldehydes.
Fe(BF4)2-Catalyzed Inter- and Intramolecular Carbonyl-Ene Reaction of Trifluoropyruvate
Authors: Ollevier Thierry , Meng Di
Published: December 2017

Inter- and intramolecular carbonyl-ene reactions have been developed using 5 mol% Fe(BF4)2 as catalyst, affording homoallylic alcohols in 36–87% isolated yields. This catalyst, prepared from FeCl2 and AgBF4, is the first FeII Lewis acid reported for the carbonyl-ene reaction using ethyl trifluoropyruvate. The method was successfully applied to the reaction of various 1,1-disubstituted alkenes with ethyl trifluoropyruvate and to the cyclization of citronellal.
Motion of a Janus particle very near a wall
Authors: Rashidi Aidin , Wirth Christopher L.
Published: December 2017

This article describes the simulated Brownian motion of a sphere comprising hemispheres of unequal zeta potential (i.e., “Janus” particle) very near a wall. The simulation tool was developed and used to assist in the methodology development for applying Total Internal Reflection Microscopy (TIRM) to anisotropic particles. Simulations of the trajectory of a Janus sphere with cap density matching that of the base particle very near a boundary were used to construct 3D potential energy landscapes that were subsequently used to infer particle and solution properties, as would be done in a TIRM measurement. Results showed that the potential energy landscape of a Janus sphere has a transition region at the location of the boundary between the two Janus halves, which depended on the relative zeta potential magnitude. The potential energy landscape was fit to accurately obtain the zeta potential of each hemisphere, particle size, minimum potential energy position and electrolyte concentration, or Debye length. We also determined the appropriate orientation bin size and regimes over which the potential energy landscape should be fit to obtain system properties. Our simulations showed that an experiment may require more than 106 observations to obtain a suitable potential energy landscape as a consequence of the multivariable nature of observations for an anisotropic particle. These results illustrate important considerations for conducting TIRM for anisotropic particles.
Characterizing the geometric and electronic structure of defects in the “29” copper surface oxide
Authors: Therrien Andrew J. , Hensley Alyssa J. R. , Zhang Renqin , Pronschinske Alex , Marcinkowski Matthew D. , McEwen Jean-Sabin , Sykes E. Charles H.
Published: December 2017

The geometric and electronic structural characterization of thin film metal oxides is of fundamental importance to many fields such as catalysis, photovoltaics, and electrochemistry. Surface defects are also well known to impact a material’s performance in any such applications. Here, we focus on the “29” oxide Cu2O/Cu(111) surface and we observe two common structural defects which we characterize using scanning tunneling microscopy/spectroscopy and density functional theory. The defects are proposed to be O vacancies and Cu adatoms, which both show unique topographic and spectroscopic signatures. The spatially resolved electronic and charge state effects of the defects are investigated, and implications for their reactivity are given.
The discharge characteristics in nitrogen helicon plasma
Authors: Zhao Gao , Wang Huihui , Si Xinlu , Ouyang Jiting , Chen Qiang , Tan Chang
Published: December 2017

Discharge characteristics of helicon plasma in nitrogen and argon-nitrogen mixtures were investigated experimentally by using a Langmuir probe, a B-dot probe, and an optical emission spectrum. Helicon wave discharge is confirmed by the changes of electron density and electromagnetic signal amplitude with the increasing RF power, which shows three discharge stages in nitrogen, corresponding to E-mode, H-mode, and W-mode discharges in helicon plasma, respectively. Discharge images in the radial cross section at different discharge modes through an intensified charge coupled device (ICCD) show a rapid increase in luminous intensity along with the RF power. When the nitrogen discharge is in the W-mode, the images show that the strongest luminance locates near the plasma boundary and no blue core appears in the axial center of tube, which is always observed in argon W-mode discharge. The “big blue” or blue core is a special character in helicon plasma, but it has not been observed in nitrogen helicon plasma. In nitrogen-argon mixtures, a weak blue core is observed in ICCD images since the nitrogen content is increased. The electric field turns to the periphery in the distribution of the radial field and the electron temperature decreases with the increasing nitrogen content, especially when the blue core disappears. The different behaviors of the electron impact and the energy consumption in nitrogen helicon plasma are suggested to be responsible for the decrease in electron energy and the change in the electric field distribution.
Dielectric, magnetic, ferroelectric, and Mossbauer properties of bismuth substituted nanosized cobalt ferrites through glycine nitrate synthesis method
Authors: Routray Krutika L. , Sanyal Dirtha , Behera Dhrubananda
Published: December 2017

CoFe2-xBixO4 nanoferrites with x = 0, 0.05, 0.1, 0.5, and 1.0 have been synthesized by the glycine nitrate process. The present study investigates the effect of Bi3+ substitution on the microstructural, dielectric, ferroelectric, magnetic, and Mossbauer properties of CoFe2O4 nanoparticles. The X-ray diffraction technique was used to confirm the phase purity and estimate the crystallite size which revealed the formation of a secondary phase when Bi3+ concentration exceeds x = 0.5. Transmission electron microscopy indicated the formation of grains by aggregation of small crystallites with a reduction in grain size to 20 nm with an increase in Bi3+ content and also divulged the lattice parameter value to be 8.378 Å, confirming the crystalline nature of the synthesised sample. Dielectric properties performed in the frequency range of 100 Hz to 1 MHz determined that the dielectric behavior is attributed to the Maxwell-Wagner polarization and the activation energy of the specimens is calculated from the dielectric measurements. The hysteresis curve indicated the ferrimagnetic nature of the samples. The samples also exhibited a well saturated P-E loop with gradual lowering in remenant polarization, coercive field, and saturation polarization with an increase in bismuth concentration. Mössbauer spectroscopy analysis confirmed the changes in magnetic moment of ions, their coupling with neighbouring ions, and cation exchange interactions. Owing to the high physical, thermal, and chemical stabilities, these magnetic ceramics, CoFe2-xBixO4, possesses tremendous potential in major understanding of magnetism and in magnetic recording applications for high density information storage.
Spectrally resolved single-molecule electrometry
Authors: Ruggeri F. , Krishnan M.
Published: December 2017

Escape-time electrometry is a recently developed experimental technique that offers the ability to measure the effective electrical charge of a single biomolecule in solution with sub-elementary charge precision. The approach relies on measuring the average escape-time of a single charged macromolecule or molecular species transiently confined in an electrostatic fluidic trap. Comparing the experiments with the predictions of a mean-field model of molecular electrostatics, we have found that the measured effective charge even reports on molecular conformation, e.g., folded or disordered state, and non-uniform charge distribution in disordered proteins or polyelectrolytes. Here we demonstrate the ability to use the spectral dimension to distinguish minute differences in electrical charge between individual molecules or molecular species in a single simultaneous measurement, under identical experimental conditions. Using one spectral channel for referenced measurement, this kind of photophysical distinguishability essentially eliminates the need for accurate knowledge of key experimental parameters, otherwise obtained through intensive characterization of the experimental setup. As examples, we demonstrate the ability to detect small differences (∼5%) in the length of double-stranded DNA fragments as well as single amino acid exchange in an intrinsically disordered protein, prothymosin α.
Electrode erosion properties of gas spark switches for fast linear transformer drivers
Authors: Li Xiaoang , Pei Zhehao , Zhang Yuzhao , Liu Xuandong , Li Yongdong , Zhang Qiaogen
Published: December 2017

Fast linear transformer drivers (FLTDs) are a popular and potential route for high-power devices employing multiple “bricks” in series and parallel, but they put extremely stringent demands on gas switches. Electrode erosion of FLTD gas switches is a restrictive and unavoidable factor that degrades performance and limits stability. In this paper, we systematically investigated the electrode erosion characteristics of a three-electrode field distortion gas switch under the typical working conditions of FLTD switches, and the discharge current was 7–46 kA with 46–300 ns rise time. A high speed frame camera and a spectrograph were used to capture the expansion process and the spectral emission of the spark channel was used to estimate the current density and the spark temperature, and then the energy fluxes and the external forces on the electrode surface were calculated. A tens of kilo-ampere nanosecond pulse could generate a 1011 W/m2 energy flux injection and 1.3–3.5 MPa external pressure on the electrode surface, resulting in a millimeter-sized erosion crater with the maximum peak height Rz reaching 100 μm magnitude. According to the morphological images by a laser scanning confocal microscope, the erosion crater of a FLTD switch contained three kinds of local morphologies, namely a center boiling region, an overflow region and a sputtering region. In addition, the crater size, the surface roughness, and the mass loss were highly dependent on the current amplitude and the transferred charge. We also observed Morphology Type I and Type II, respectively, with different pulse parameters, which had an obvious influence on surface roughness and mass loss. Finally, the quantitative relationship between the electrode mass loss and the pulse parameter was clarified. The transferred charge and the current amplitude were proved to be the main factors determining the electrode mass loss of a FLTD switch, and a least squares fitting expression for mass loss was also obtained.
Current control of time-averaged magnetization in superparamagnetic tunnel junctions
Authors: Bapna Mukund , Majetich Sara A.
Published: December 2017

This work investigates spin transfer torque control of time-averaged magnetization in a small 20 nm × 60 nm nanomagnet with a low thermal stability factor, Δ ∼ 11. Here, the nanomagnet is a part of a magnetic tunnel junction and fluctuates between parallel and anti-parallel magnetization states with respect to the magnetization of the reference layer generating a telegraph signal in the current versus time measurements. The response of the nanomagnet to an external field is first analyzed to characterize the magnetic properties. We then show that the time-averaged magnetization in the telegraph signal can be fully controlled between +1 and −1 by voltage over a small range of 0.25 V. NIST Statistical Test Suite analysis is performed for testing true randomness of the telegraph signal that the device generates when operated at near critical current values for spin transfer torque. Utilizing the probabilistic nature of the telegraph signal generated at two different voltages, a prototype demonstration is shown for multiplication of two numbers using an artificial AND logic gate.
Improved perovskite morphology and crystallinity using porous PbI2 layers for efficient planar heterojunction solar cells
Authors: Jia Xianyu , Hu Ziyang , Xu Jie , Huang Like , Zhang Jing , Zhang Jianjun , Zhu Yuejin
Published: December 2017

We demonstrate the flexible and facile use of porous PbI2 layers to fabricate high quality perovskite films with a dense surface and without residual PbI2. PbI2 precursor solutions by adding polystyrene pore-forming agents are first spin-coated to fabricate the wet film. A porous PbI2 layer is formed by washing off polystyrene using organic solvents. The porous PbI2 layer not only serves as a channel for transporting the CH3NH3I solution but also offers extremely enlarged contact areas, facilitating interfacial reaction with CH3NH3I. Shiny smooth perovskite films with excellent electronic quality and solar cells with an efficiency up to 17% are obtained.
Irreversible metal-insulator transition in thin film VO2 induced by soft X-ray irradiation
Authors: Singh V. R. , Jovic V. , Valmianski I. , Ramirez J. G. , Lamoureux B. , Schuller Ivan K. , Smith K. E.
Published: December 2017

In this study, we show the ability of soft x-ray irradiation to induce room temperature metal-insulator transitions (MITs) in VO2 thin films grown on R-plane sapphire. The ability of soft x-rays to induce MIT in VO2 thin films is confirmed by photoemission spectroscopy and soft x-ray spectroscopy measurements. When irradiation was discontinued, the systems do not return to the insulating phase. Analysis of valence band photoemission spectra revealed that the density of states (DOSs) of the V 3d band increased with irradiation time, while the DOS of the O 2p band decreased. We use these results to propose a model in which the MIT is driven by oxygen desorption from thin films during irradiation.
Reforms in Morocco: monitoring the orbit and reading the trajectory
Authors: al-Akhssassi Mohamad
Published: December 2017

Since 2011, Morocco has been undergoing a series of political, constitutional and institutional reforms, including the issue of rights. These reforms were a response to the February 20 movement that emerged against the background of the Arab Spring. Prompted by this movement and its nationwide protests, the King of Morocco delivered a speech in March 2011 on reform and modernization, resulting in the rapid drafting and adoption of a new Moroccan constitution in June 2011. After a referendum on the constitutional reforms in July 2011, parliamentary elections were held in which a coalition government led by the Justice and Development Party (JDP) came to power. This paper analyzes the context of the 2011 constitution and assesses the trajectory of the constitutional reforms up to 2015.
Foreign trade statistics of Arab countries: selected indicators
Authors: El-Khoury Gabi
Published: December 2017

This statistical file is mainly concerned with the external merchandise trade of Arab countries, which accounts for approximately 77% of the total trade of Arab goods and services due to the large share of oil and gas in the Arab foreign trade.
Theology of perception
Authors: Andretta Marilisa
Published: December 2017

Communication science and art confront one another especially in research on the interdependence between eye and mind, in assessing how what is visually perceived relates to the true nature of the human being and the real world. Surely, though, in the Jewish-Christian theological sphere, the ear plays an extremely important part too. G. Ravasi defined Jews, Christians and Muslims as ‘people of speech and listening’. The great monotheistic religions are religions of listening.
Cilia loss sensitizes cells to transformation by activating the mevalonate pathway
Authors: Deng Yue-Zhen , Cai Zhen , Shi Shuo , Jiang Hao , Shang Yu-Rong , Ma Ning , Wang Jing-Jing , Guan Dong-Xian , Chen Tian-Wei , Rong Ye-Fei , Qian Zhen-Yu , Zhang Er-Bin , Feng Dan , Zhou Quan-Li , Du Yi-Nan , Liu Dong-Ping , Huang Xing-Xu , Liu Lu-Ming , Chin Eugene , Li Dang-Sheng , Wang Xiao-Fan , Zhang Xue-Li , Xie Dong
Published: December 2017

Although cilia loss and cell transformation are frequently observed in the early stage of tumorigenesis, the roles of cilia in cell transformation are unknown. In this study, disrupted ciliogenesis was observed in cancer cells and pancreatic cancer tissues, which facilitated oncogene-induced transformation of normal pancreatic cells (HPDE6C7) and NIH3T3 cells through activating the mevalonate (MVA) pathway. Disruption of ciliogenesis up-regulated MVA enzymes through β catenin–T cell factor (TCF) signaling, which synchronized with sterol regulatory element binding transcription factor 2 (SREBP2), and the regulation of MVA by β-catenin–TCF signaling was recapitulated in a mouse model of pancreatic ductal adenocarcinoma (PDAC) and human PDAC samples. Moreover, disruption of ciliogenesis by depleting Tg737 dramatically promoted tumorigenesis in the PDAC mouse model, driven by KrasG12D, which was inhibited by statin, an inhibitor of the MVA pathway. Collectively, this study emphasizes the crucial roles of cilia in governing the early steps of the transformation by activating the MVA pathway, suggesting that statin has therapeutic potential for pancreatic cancer treatment.
The prokaryotic Na+/Ca2+ exchanger NCX_Mj transports Na+ and Ca2+ in a 3:1 stoichiometry
Authors: Shlosman Irina , Marinelli Fabrizio , Faraldo-Gómez José D. , Mindell Joseph A.
Published: December 2017

Intracellular Ca2+ signals control a wide array of cellular processes. These signals require spatial and temporal regulation of the intracellular Ca2+ concentration, which is achieved in part by a class of ubiquitous membrane proteins known as sodium–calcium exchangers (NCXs). NCXs are secondary-active antiporters that power the translocation of Ca2+ across the cell membrane by coupling it to the flux of Na+ in the opposite direction, down an electrochemical gradient. Na+ and Ca2+ are translocated in separate steps of the antiport cycle, each of which is thought to entail a mechanism whereby ion-binding sites within the protein become alternately exposed to either side of the membrane. The prokaryotic exchanger NCX_Mj, the only member of this family with known structure, has been proposed to be a good functional and structural model of mammalian NCXs; yet our understanding of the functional properties of this protein remains incomplete. Here, we study purified NCX_Mj reconstituted into liposomes under well-controlled experimental conditions and demonstrate that this homologue indeed shares key functional features of the NCX family. Transport assays and reversal-potential measurements enable us to delineate the essential characteristics of this antiporter and establish that its ion-exchange stoichiometry is 3Na+:1Ca2+. Together with previous studies, this work confirms that NCX_Mj is a valid model system to investigate the mechanism of ion recognition and membrane transport in sodium–calcium exchangers.
CscoreTool: fast Hi-C compartment analysis at high resolution
Authors: Zheng Xiaobin , Zheng Yixian
Published: December 2017

The genome-wide chromosome conformation capture (Hi-C) has revealed that the eukaryotic genome can be partitioned into A and B compartments that have distinctive chromatin and transcription features. Current Principle Component Analyses (PCA)-based method for the A/B compartment prediction based on Hi-C data requires substantial CPU time and memory. We report the development of a method, CscoreTool, which enables fast and memory-efficient determination of A/B compartments at high resolution even in datasets with low sequencing depth.

Availability and implementation

https://github.com/scoutzxb/CscoreTool

Supplementary information

Supplementary data are available at Bioinformatics online.
An industrial security system for human-robot coexistence
Authors: Long Philip , Chevallereau Christine , Chablat Damien , Girin Alexis
Published: December 2017

Purpose

The installation of industrial robots requires security barriers, a costly, time-consuming exercise. Collaborative robots may offer a solution; however, these systems only comply with safety standards if operating at reduced speeds. The purpose of this paper is to describe the development and implementation of a novel security system that allows human–robot coexistence while permitting the robot to execute much of its task at nominal speed.

Design/methodology/approach

The security system is defined by three modes: a nominal mode, a coexistence mode and a gravity compensation mode. Mode transition is triggered by three lasers, two of which are mechanically linked to the robot. These scanners create a dynamic envelope around the robot and allow the detection of operator presence or environmental changes. To avoid velocity discontinuities between transitions, the authors propose a novel time scaling method.

Findings

The paper describes the system’s mechanical, software and control architecture. The system is demonstrated experimentally on a collaborative robot and is compared with the performance of a state-of-art security system. Both a qualitative and quantitative analysis of the new system is carried out.

Practical implications

The mode transition method is easily implemented, requires little computing power and leaves the trajectories unchanged. As velocity discontinuities are avoided, motor wear is reduced. The execution time is substantially less than a commercial alternative. These advantages can lead to economic benefits in high-volume manufacturing environments.

Originality/value

This paper proposes a novel system that is based on industrial material but can generate dynamic safety zones for a collaborative robot.
The Pransky interview: Mel Torrie, Founder, CEO and President of Autonomous Solutions, Inc.
Authors: Pransky Joanne
Published: December 2017

Purpose

The following paper is a “Q&A interview” conducted by Joanne Pransky of Industrial Robot Journal as a method to impart the combined technological, business and personal experience of a prominent, robotic industry engineer-turned successful innovator and leader, regarding the challenges of bringing technological discoveries to fruition. This paper aims to discuss these issues.

Design/methodology/approach

The interviewee is Mel Torrie, CEO and President of Autonomous Solutions, Inc. (ASI). ASI manufactures an OEM/vendor independent software and hardware solution retrofitted to existing equipment to create a wide variety of fully autonomous vehicles spanning agriculture, mining, automotive, industrial cleaning, security and government/military applications. In this interview, Torrie shares how he first got started in the robotics field along with his experiences in running his ground-breaking startup.

Findings

In 1999, Torrie received a Master’s Degree in Electrical Engineering at Utah State University (USU) where he worked on two National Aeronautics and Space Administration (NASA) space shuttle payloads. After his work at USU, he managed robotics development programs for John Deere, the US Department of Defense and the US Department of Energy. He founded ASI, a spin-off of the Center of Self Organizing and Intelligent Systems (CSOIS) at USU, in 2000.

Originality/value

Torrie was a pioneer and visionary who bootstrapped ASI from the beginning. Under Torrie’s leadership, ASI raised over $85m in a unique business model where there is no equity but only strategic partners. These foremost companies are given exclusive rights to their vertical market and jointly own their industry’s driverless vehicle’s intellectual property (IP) with ASI. The vehicles are developed and tested at ASI’s 100-acre proving ground facility in Utah. To date, ASI’s more than 100 employees and their business partners have automated 75 different vehicle types and ASI continues to create new markets. Some of ASI’s notable installations include the Bingham Canyon Mine clean-up effort; BatCat, the teleoperated CAT telehandler for the Los Angeles Police Department; and the robotic durability testing program with Ford Motors, Toyota, Fiat Chrysler Automotive, Hyundai, General Motors as well as other private proving grounds.
Evaluation of dry port implementation in Ghana
Authors: Owusu Kwateng Kwame , Donkoh Archibald , Muntaka Abdul Samed
Published: December 2017

Purpose

Congestion at Ghana’s main seaports is a problem that has received much attention recently. This is as a result of continuous increase in containerized cargo. To increase the capacity of Ghana’ seaport, the Ministry of Transport through the Ghana Shippers Council initiated the Boankra Inland Port Project. The aim of this paper is to assess the feasibility and economic effects of implementing the Boankra Inland Port as a solution to reduce congestion at the main seaports, as well as reduce transportation cost.

Design/methodology/approach

The location of the inland port was assessed using the gravitational model. Data for the gravitational model are distances from the main seaports in Ghana and Boankra Inland Port to major hinterland destinations and population of the destinations. Also, 210 respondents were selected and interviewed on contribution of the dry port concept to the economy and transportation management in Ghana.

Findings

The results of the gravitational model support the location of Boankra as an inland port. A further comparison between Tema and Takoradi shows that Tema has a better location as a distribution center than Takoradi.

Practical implications

Although Tema and Takoradi are the main seaports in Ghana, the implementation of the Boankra inland port will reduce the transportation cost for cargo with hinterland destinations, therefore making it a rational and cost-efficient location for transit transportation.

Originality/value

This paper is among the first significant attempts to evaluate the suitability of inland port implementation in Ghana.
Trade‐offs between water loss and gas exchange influence habitat suitability of a woodland salamander
Authors: Riddell Eric A. , McPhail Jared , Damm Jason D. , Sears Michael W.
Published: December 2017

Reversible acclimation increases resilience to environmental stress, but acclimation may have hidden costs due to underlying linkages between related physiological traits. These linkages might result in trade‐offs that undermine whole‐organism performance if the change in a related trait reduces the net benefits of acclimation or increases susceptibility to alternative environmental stressors.

Metabolic rate and water loss rate are two fundamental physiological traits that could interact due to their dependence on gas exchange across shared physical surfaces. Reductions in water loss rate in response to dehydration stress might reduce metabolic rate by constraining the flux of both water and oxygen.

We examined acclimation of metabolic rate and water loss rate using a species of woodland salamander (Plethodon metcalfi) in response to temperature and humidity using a full factorial experimental design. We controlled the evaporative demand of the air across temperatures to assess temperature and humidity as independent cues for acclimation. We predicted that reductions in water loss rate would coincide with reductions in metabolic rate in response to temperature due to shared physical and chemical pathways. We also assessed acclimation of heart rates as a potential compensatory mechanism used to promote oxygen delivery. We integrated these responses into a biophysical model developed from first principles to demonstrate the potential for these interactions to influence habitat suitability.

We found that reductions in water loss rates during thermal acclimation were associated with simultaneous reductions in metabolic rates, and we did not find a compensatory response in heart rates. We suggest that these linkages underlie whole‐organism strategies (e.g. physiological dormancy or arousal) for reducing the energetic costs imposed by warm temperatures. The biophysical model suggested that the interaction between these two traits potentially structures phenotypic variation in our population because certain combinations of trait values were incapable of reaching positive energy balance.

Trade‐offs between linked physiological traits potentially structure whole‐organism strategies for responding to environmental stressors and constrain phenotypic variation. Therefore, predictions of the benefits of acclimation must be interpreted cautiously without knowledge of the underlying trade‐offs among linked physiological traits.

A plain language summary is available for this article.
The mechanistic basis of demographic Allee effects: The search for mates
Authors: Kuparinen Anna
Published: December 2017

In Focus: Berec, L., Kremer, A.M., Bernhauverova, V., & Drake, J.M. (2017). . Journal of Animal Ecology, 87, 24–35. https://doi.org/10.1111/1365-2656.12662

In Focus: Shaw, A.K., Kokko, H., & Neubert, M.G. (2017). . Journal of Animal Ecology, 87, 36–46. https://doi.org/10.1111/1365-2656.12658

Lowered population growth ability at low abundances is called the demographic Allee effect. The difficulty of finding mates in a sparse population is the best documented pathway through which a demographic Allee effect might arise. The articles in focus here aim to establish the mechanistic links between mate search component Allee effects and the emergent demographic Allee effect manifested at the level of population growth rate. The authors discover that limitations in the time invested in mate searching generates demographic Allee effects and that the population level adaptations of mate search time are likely to be dependent on the prevailing population density. Trade‐offs between mate search, survival and reproductive outputs are key in understanding optimal mate search strategies and their fitness consequences. The present studies provide guidelines to identify populations at risk of experiencing demographic Allee effects at low abundances.
Dynamic environments of fungus‐farming termite mounds exert growth‐modulating effects on fungal crop parasites
Authors: Katariya Lakshya , Ramesh Priya B. , Borges Renee M.
Published: December 2017

This study investigated for the first time the impact of the internal mound environment of fungus‐growing termites on the growth of fungal crop parasites. Mounds of the termite Odontotermes obesus acted as (i) temperature and relative humidity (RH) ‘stabilisers’ showing dampened daily variation and (ii) ‘extreme environments’ exhibiting elevated RH and CO2 levels, compared to the outside. Yet, internal temperatures exhibited seasonal dynamics as did daily and seasonal CO2 levels. During in situ experiments under termite‐excluded conditions within the mound, the growth of the crop parasite Pseudoxylaria was greater inside than outside the mound, i.e., Pseudoxylaria is ‘termitariophilic’. Also, ex situ experiments on parasite isolates differing in growth rates and examined under controlled conditions in the absence of termites revealed a variable effect with fungal growth decreasing only under high CO2 and low temperature conditions, reflecting the in situ parasite growth fluctuations. In essence, the parasite appears to be adapted to survive in the termite mound. Thus the mound microclimate does not inhibit the parasite but the dynamic environmental conditions of the mound affect its growth to varying extents. These results shed light on the impact of animal‐engineered structures on parasite ecology, independent of any direct role of animal engineers.
Improving quit rates of web‐delivered interventions for smoking cessation: full‐scale randomized trial of WebQuit.org versus Smokefree.gov
Authors: Bricker Jonathan B. , Mull Kristin E. , McClure Jennifer B. , Watson Noreen L. , Heffner Jaimee L.
Published: December 2017

Background and aims

Millions of people world‐wide use websites to help them quit smoking, but effectiveness trials have an average 34% follow‐up data retention rate and an average 9% quit rate. We compared the quit rates of a website using a new behavioral approach called Acceptance and Commitment Therapy (ACT; WebQuit.org) with the current standard of the National Cancer Institute's (NCI) Smokefree.gov website.

Design

A two‐arm stratified double‐blind individually randomized trial (n = 1319 for WebQuit; n = 1318 for Smokefree.gov) with 12‐month follow‐up.

Setting

United States.

Participants

Adults (n = 2637) who currently smoked at least five cigarettes per day were recruited from March 2014 to August 2015. At baseline, participants were mean [standard deviation (SD)] age 46.2 years (13.4), 79% women and 73% white.

Interventions

WebQuit.org website (experimental) provided ACT for smoking cessation; Smokefree.gov website (comparison) followed US Clinical Practice Guidelines for smoking cessation.

Measurements

The primary outcome was self‐reported 30‐day point prevalence abstinence at 12 months.

Findings

The 12‐month follow‐up data retention rate was 88% (2309 of 2637). The 30‐day point prevalence abstinence rates at the 12‐month follow‐up were 24% (278 of 1141) for WebQuit.org and 26% (305 of 1168) for Smokefree.gov [odds ratio (OR) = 0.91; 95% confidence interval (CI) = 0.76, 1.10; P = 0.334] in the a priori complete case analysis. Abstinence rates were 21% (278 of 1319) for WebQuit.org and 23% (305 of 1318) for Smokefree.gov (OR = 0.89 (0.74, 1.07; P = 0.200) when missing cases were imputed as smokers. The Bayes factor comparing the primary abstinence outcome was 0.17, indicating ‘substantial’ evidence of no difference between groups.

Conclusions

WebQuit.org and Smokefree.gov had similar 30‐day point prevalence abstinence rates at 12 months that were descriptively higher than those of prior published website‐delivered interventions and telephone counselor‐delivered interventions.
Stalagmites from western Thailand: preliminary investigations and challenges for palaeoenvironmental research
Authors: Chawchai Sakonvan , Liu Guangxin , Bissen Raphael , Jankham Kampanart , Paisonjumlongsri Warisa , Kanjanapayont Pitsanupong , Chutakositkanon Vichai , Choowong Montri , Pailoplee Santi , Wang Xianfeng
Published: December 2017

Locating suitable caves and stalagmites for palaeoenvironmental and palaeoclimatic studies can be challenging. Isotopic geochemical analyses, albeit commonly performed for palaeoclimatic reconstruction, are also time consuming and costly. Therefore, petrographic and non‐destructive morphological studies on speleothems are desirable to facilitate sample selection for further analysis. In this study, 20 caves were surveyed in Ban Rai district, Uthai Thani province in western Thailand. After external physical observations in the field, three stalagmite samples were collected from Tham Nam Cave to test their potential for palaeoclimatic research. Firstly, the stalagmites were scanned by X‐ray computed tomography (CT scanning) and subsequently the CT images were compared with petrographic inspections. Columnar fabrics show the highest density, whereas closed and open dendritic fabrics have medium and the lowest densities, respectively. Layers near the top and bottom of the three stalagmites were dated by U‐Th mass spectrometric techniques. All three samples were deposited between c. 87 and c. 105 ka ago; therefore, they are probably the oldest stalagmites that have been reported so far from mainland Southeast Asia. However, their physical features indicate that all the samples have suffered from postdepositional dissolution, and are unlikely to be suitable for palaeoclimatic research. The internal dissolution feature of stalagmites, however, cannot be identified by visual inspection of uncut samples. We hereby argue that CT images are useful to characterize stalagmite petrography, in particular fabric, porosity and density. Such features can be used to select the ideal plane of a stalagmite for sectioning, to maximize the chances of robust climatic reconstruction.
Relationship between reticular pseudodrusen and choroidal thickness in intermediate age‐related macular degeneration
Authors: Ho Chi YD , Lek Jia J , Aung Khin Z , McGuinness Myra B , Luu Chi D , Guymer Robyn H
Published: December 2017

Importance

Reticular pseudodrusen (RPD) is strongly associated with late age‐related macular degeneration (AMD) but their aetiology remains unknown. RPD have been associated with reduced choroidal thickness (ChT) but most studies are limited by small sample size and varying severity of AMD.

Background

To investigate the relationship between choroidal thickness and RPD in eyes with intermediate AMD (iAMD), controlling for variables known to influence ChT.

Design

Retrospective cohort study.

Participants

Participants were recruited from Centre for Eye Research Australia.

Methods

Colour fundus photographs, fundus auto fluorescence, near‐infrared and spectral‐domain ocular coherence tomography (OCT) were graded for RPD. ChT was measured from enhanced‐depth imaging OCT scans at the centre of fovea, 1500 and 3000 μm nasal, temporal, superior and inferior from centre of fovea.

Main Outcome Measures

ChT between RPD and non‐RPD group.

Results

A total of 297 eyes from 152 subjects were included. A total of 84 (28%) had RPD and were older than non‐RPD group (75.1 ± 5.4 years and 68.7 ± 6.9 years, respectively; P < 0.001). In unadjusted analysis, the RPD group was significantly associated with thinner choroids across all measured locations (P ≤ 0.022). After adjustment for variables, the presence of RPD was no longer associated with ChT (P ≥ 0.132 for all locations) but age (P < 0.001) and refractive error (P = 0.002) remained significantly associated with ChT.

Conclusions and Relevance

Age and refractive error, rather than RPD, was significantly associated with reduced ChT in eyes with iAMD. Choroidal insufficiency may be a less important variable in RPD aetiology than previously considered.