bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergistic Effect in Au-Cu Bimetallic Catalysts for the Valorization of Lignin-Derived Compounds
Authors: Stucchi Marta , Capelli Sofia , Cardaci Simone , Cattaneo Stefano , Jouve Andrea , Beck Andrea , Sáfrán György , Evangelisti Claudio , Villa Alberto , Prati Laura
Published: March 2020

The selective oxidation of veratryl alcohol as lignin-derived compound was studied under mild conditions, using Au-Cu catalysts synthesized from pre-formed nanoparticles with different Au:Cu molar ratios. Bimetallic catalysts show higher activity compared to monometallic counterparts, highlighting a clear synergistic effect. By comparing the physico-chemical surface properties of catalysts supported on carbon and Al2O3, we were able to establish a strong support effect, with alumina-based catalysts being more active than carbon-supported ones. Moreover, TEM and X-ray photoelectron spectroscopy (XPS) analyses showed a different composition of nanoparticles (NPs) and metal exposure, and we established that Au is the active phase of the reaction. The co-presence of Au and Cu species, and their different interaction with the support, enabled obtaining more than 70% conversion of veratryl alcohol to veratryl aldehyde as a unique product. Moreover, the Au1Cu1 supported on alumina catalyst was recovered by filtration and reused without significant loss of activity and selectivity up to four times.
Substitution of Co with Ni in Co/Al2O3 Catalysts for Fischer–Tropsch Synthesis
Authors: Martinelli Michela , Karuturi Sai Charan , Garcia Richard , Watson Caleb D. , Shafer Wilson D. , Cronauer Donald C. , Kropf A. Jeremy , Marshall Christopher L. , Jacobs Gary
Published: March 2020

The effect of cobalt substitution with nickel was investigated for the Fischer–Tropsch synthesis reaction. Catalysts having different Ni/Co ratios were prepared by aqueous incipient wetness co-impregnation, characterized, and tested using a continuously stirred tank reactor (CSTR) for more than 200 h. The addition of nickel did not significantly modify the morphological properties measured. XRD, STEM, and TPR-XANES results showed intimate contact between nickel and cobalt, strongly suggesting the formation of a Co-Ni solid oxide solution in each case. Moreover, TPR-XANES indicated that nickel addition improves the cobalt reducibility. This may be due to H2 dissociation and spillover, but is more likely the results of a chemical effect of intimate contact between Co and Ni resulting in Co-Ni alloying after activation. FTS testing revealed a lower initial activity when nickel was added. However, CO conversion continuously increased with time on-stream until a steady-state value (34%–37% depending on Ni/Co ratio) was achieved, which was very close to the value observed for undoped Co/Al2O3. This trend suggests nickel can stabilize cobalt nanoparticles even at a lower weight percentage of Co. Currently, the cobalt price is 2.13 times the price of nickel. Thus, comparing the activity/price, the catalyst with a Ni/Co ratio of 25/75 has better performance than the unpromoted catalyst. Finally, nickel-promoted catalysts exhibited slightly higher initial selectivity for light hydrocarbons, but this difference typically diminished with time on-stream; once leveling off in conversion was achieved, the C5+ selectivities were similar (≈ 80%) for Ni/Co ratios up to 10/90, and only slightly lower (≈ 77%) at Ni/Co of 25/75.
Effects of a Need-Supportive Motor Skill Intervention on Children’s Motor Skill Competence and Physical Activity
Authors: Lee Joonyoung , Zhang Tao , Chu Tsz , Gu Xiangli
Published: March 2020

A need-supportive environment can provide various motivational benefits to impact children’s psychomotor developmental levels. However, very little is known about the effects of need-supportive motor skill intervention on children’s motor skill competence and physical activity by gender. Guided by self-determination theory (SDT), this study aimed to (a) investigate the effect of a need-supportive fundamental movement skill (FMS) program on children’s FMS competence and moderate-to-vigorous physical activity (MVPA), and (b) explore potential gender differences in these effects. Thirty-six children (63.8% girls; Mage = 6.52 ± 0.97) participated and were divided into two groups: an intervention group (24 need-supportive FMS sessions over eight weeks) and a control group. A repeated-measures multivariate analysis of variance (MANOVA) was used to examine the influence of the motor skill intervention on FMS competence and MVPA over time by group (intervention, control) and gender (boys, girls). The results showed (a) significant group differences between the intervention and control group in FMS competence and MVPA (p < 0.001), (b) non-significant gender differences between boys and girls in FMS competence and MVPA (p = 0.85), and (c) non-significant interaction effects over time (p = 0.52). The findings highlight that a need-supportive FMS program may enhance FMS development and daily physical activity for both genders during the early school years.
A Sensitivity Study of High-Resolution Climate Simulations for Greece
Authors: Politi Nadia , Sfetsos Athanasios , Vlachogiannis Diamando , Nastos Panagiotis T. , Karozis Stylianos
Published: March 2020

In the present study, the ability of the Advanced Weather Research and Forecasting numerical model (WRF-ARW) to perform climate regionalization studies in the topographically complex region of Greece, was examined in order to explore the possibility of a more reliable selection of physical schemes for the simulation of historical and future high resolution (5 km) climate model experiments to investigate the impact of climate change. This work is directly linked to a previous study investigating the performance of seven different model setups for one year, from which the need was derived for further examination of four different simulations to investigate the model sensitivity on the representation of surface variables statistics during a 5-year period. The results have been compared with observational data for maximum and minimum air temperature and daily precipitation through statistical analysis. Clear similarities were found in precipitation patterns among simulations and observations, yielding smoothly its inter-annual variability, especially during the wettest months and summer periods, with the lowest positive percentage BIAS calculated at about 19% for the selected combination of physics parameterizations (PP3). Regarding the maximum and minimum temperature, statistical analysis showed a high correlation above 0.9, and negative bias around 1−1.5 °C, and positive bias near 2 °C, respectively.
Study on the Growth and Properties of Electrolessly Deposited Thin Copper Coatings on Epoxy-Based CFRP
Authors: de Juan Sergio , Gordo Elena , Jiménez-Morales Antonia , Sirois Frédéric
Published: March 2020

In this study, copper coatings smaller than 3 µm were created by electroless deposition on epoxy-based carbon fiber-reinforced polymer (CFRP) laminates for enhancing their electrical properties. This well-known method of metallization was employed with a self-designed combination of reagents, and the coatings were studied to evaluate their physical and chemical properties. A five-stage plating strategy was applied to 40 mm × 40 mm samples, and three different coatings were produced during the work. The metal layers created were studied and characterized to evaluate their, electrical conductivity, thickness, and adhesion to substrates, among other properties. In addition, the growth mechanisms of the microstructure were analyzed in detail for a better understanding of the process. The results showed that the proposed metallization strategy presents good characteristics and is a strong candidate for enhancing the electrical performance of CFRP.
WC-Co and WC-Co-Cr Coatings for the Protection of API Pipeline Steel from Corrosion in 4% NaCl Solution
Authors: Sherif El-Sayed M. , El Rayes Magdy M. , Abdo Hany S.
Published: March 2020

Two inorganic coatings, namely 88%WC-12%Co (PSC1) and 86%WC-10%Co-4%Cr (PSC2), were deposited on the surface of an API-2H pipeline steel using high velocity oxy-fuel deposition. The corrosion of the uncoated and coated API-2H steel after their immersion in a solution of 4.0% NaCl for 1 h, 24 h, and 48 h has been studied. Various electrochemical measurements such cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and potentiostatic current versus time were employed. The surface morphology and analysis were carried out via the use of scanning electron microscopy and energy dispersive X-ray examinations. All experiments have revealed that the deposited coatings decreased the cathodic current, anodic current, corrosion current density (jCorr), absolute current versus time, and the corrosion rate (RCorr) compared to the uncoated API-2H steel. The value of jCorr decreased from 47 µA/cm2 for uncoated steel to 38 µA/cm2 for the PSC1-coated steel and 29 µA/cm2 for the PSC2-coated steel. Moreover, prolonging the time of exposure decreases the jCorr and RCorr values. The jCorr values obtained after 48 h recorded 32, 26, and 20 µA/cm2 for the uncoated, PSC1, and PSC2 samples, respectively. Moreover, applying these coatings also led to increasing the corrosion resistance (RP) after all the exposure periods of time. In addition, the PSC2 coating was found to be more protective against corrosion for the surface of the steel than the PSC1 coating.
Quantum-Heat Fluctuation Relations in Three-Level Systems Under Projective Measurements
Authors: Giachetti Guido , Gherardini Stefano , Trombettoni Andrea , Ruffo Stefano
Published: March 2020

We study the statistics of energy fluctuations in a three-level quantum system subject to a sequence of projective quantum measurements. We check that, as expected, the quantum Jarzynski equality holds provided that the initial state is thermal. The latter condition is trivially satisfied for two-level systems, while this is generally no longer true for N-level systems, with N > 2 . Focusing on three-level systems, we discuss the occurrence of a unique energy scale factor β eff that formally plays the role of an effective inverse temperature in the Jarzynski equality. To this aim, we introduce a suitable parametrization of the initial state in terms of a thermal and a non-thermal component. We determine the value of β eff for a large number of measurements and study its dependence on the initial state. Our predictions could be checked experimentally in quantum optics.
Stereoselective Crystallization of Chiral 3,4-Dimethylphenyl Glycerol Ether Complicated by Plurality of Crystalline Modifications
Authors: Bredikhin Alexander A. , Zakharychev Dmitry V. , Bredikhina Zemfira A. , Kurenkov Alexey V. , Samigullina Aida I. , Gubaidullin Aidar T.
Published: March 2020

Spontaneous resolution of Pasteur’s salt was historically the first way to obtain pure enantiomers from the racemate. The current increase in interest in the direct racemates resolution during crystallization is largely due to the opened prospects for the industrial application of this approach. The chiral 3-(3,4-dimethylphenoxy) propane-1,2-diol 1 is a synthetic precursor of practically useful amino alcohols, the enantiomers of which exhibit different biological effects. In this work, it was first discovered that racemic diol 1 is prone to spontaneous resolution. However, the crystallization process is complicated by the existence, along with the conglomerate, of two other crystalline forms. Using the differential scanning calorimetry (DSC) approach, methods have been developed to obtain individual metastable phases, and all identified modifications ((R)-1, (R+S)-1, α-rac-1, β-rac-1) were ranked by energy. The IR spectroscopy and powder X-ray diffraction (PXRD) methods demonstrated the identity of the first two forms and their proximity to the third, while β-rac-1 is significantly different from the rest. The crystal structure of the forms (R)-1 and α-rac-1 was established by the single crystal X-ray diffraction (SC-XRD) method. Preliminary information on the structure of β-rac-1 phase was obtained by the PXRD approach. Based on the information received, the experimental conditions for a successful direct resolution of racemic 1 into individual enantiomers by a preferential crystallization procedure were selected.
High-grade B-cell Lymphoma with MYC and BCL2 Rearrangement Arising from Follicular Lymphoma: Presentation as a Large Peripancreatic Mass
Authors: Shestakova Anna , Rezk Sherif , Ghasemizadeh Dara , Nael Ali , Zhao Xiaohui
Published: March 2020

Follicular lymphoma, the second most common non-Hodgkin lymphoma (NHL), primarily affects adults and shows an indolent clinical course. Rare cases of follicular lymphoma transform to a high-grade B-cell lymphoma with MYC and BCL2 rearrangements or “double-hit lymphoma”. Transformation to a “double-hit lymphoma” portends a worse prognosis and requires aggressive treatment. We report a comprehensive clinical, pathologic and radiographic review of a patient with previously undiagnosed low-grade follicular lymphoma that transformed into a “double-hit lymphoma”. The patient presented with a large heterogeneous mass 16 x 19 cm involving pancreatic head and neck and a mildly enlarged inguinal lymph node. Positron emission tomography (PET) study demonstrated Fluorodeoxyglucose (18F) (FDG)-avid peripancreatic mass. Tissue biopsy demonstrated a high-grade B-cell lymphoma with rearrangements t(14;18) and MYC, leading to the diagnosis of high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Excisional biopsy of an inguinal lymph node demonstrated low-grade follicular lymphoma. Clonality studies demonstrated the same immunoglobulin clone V7-4 in inguinal lymph node and peripancreatic mass. Therefore, diagnosis of a high-grade B-cell lymphoma with MYC and BCL2 rearrangements that transformed from a low-grade follicular lymphoma was rendered. It is ultimately important to establish a tissue-based diagnosis at the different sites that are involved with lymphoma. Patient proceeded with the aggressive treatment with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (EPOCH-R) treatment.
Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes: Evaluation of Hepatic Fibrosis and Steatosis Using Fibroscan
Authors: Tuong Tran Thi Khanh , Tran Dang Khoa , Phu Pham Quang Thien , Hong Tong Nguyen Diem , Chu Dinh Thien , Chu Dinh Toi
Published: March 2020

Patients with type 2 diabetes mellitus (T2DM) are at increased risk of non-alcoholic fatty liver disease (NAFLD) and might eventually progress to advanced fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Recommendations on whether to screen for NAFLD in diabetic patients remains conflicted between major guidelines. Transient elastography using FibroScan with CAP (controlled attenuation parameter) can assess both liver steatosis and fibrosis simultaneously. This paper took a new look at the prevalence of NAFLD and the severity of fibrosis among T2DM patients in Vietnam. The study was conducted using a cross-sectional design in T2DM adults who attended Dai Phuoc Ho Chi Minh Polyclinic and Polyclinic of Pham Ngoc Thach University of Medicine. Liver steatosis and fibrosis was assessed by FibroScan. NAFLD was diagnosed if CAP > 233 dB/m (steatosis > 5%). Data were analyzed using STATA 12 software program. We found that a total of 307 type 2 diabetic patients qualified for the study’s criteria. The prevalence of NAFLD in T2DM patients based on FibroScan was 73.3%. Rates of mild, moderate and severe steatosis were 20.5%, 21.8% and 30.9%, respectively. The prevalence of significant fibrosis (≥ F2), advanced fibrosis (≥ F3) and cirrhosis (F4) was 13.0%, 5.9% and 3.6%, respectively. On multivariate analysis, aspartate aminotransferase (AST) (OR: 1.067; 95% CI: 1.017–1.119; p = 0.008) and platelet levels (OR: 0.985; 95% CI: 0.972–0.999; p = 0.034) were independent of risk factors of advanced fibrosis. Thus, our study supports screening for NAFLD and for evaluating the severity of liver fibrosis in T2DM patients.
Advanced Ankle and Foot Sonoanatomy: Imaging Beyond the Basics
Authors: Hung Chen-Yu , Chang Ke-Vin , Mezian Kamal , Naňka Ondřej , Wu Wei-Ting , Hsu Po-Cheng , Özçakar Levent
Published: March 2020

Ankle/foot pain is a common complaint encountered in clinical practice. Currently, due to the complex anatomy, the diagnosis and management of the underlying musculoskeletal disorders are extremely challenging. Nowadays, high-resolution ultrasound has emerged as the first-line tool to evaluate musculoskeletal disorders. There have been several existing protocols describing the fundamental sonoanatomy of ankle/foot joints. However, there are certain anatomic structures (e.g., Lisfranc ligament complex or Baxter nerve) which are also clinically important. As they are rarely elaborated in the available literature, a comprehensive review is necessary. In this regard, the present article aims to brief the regional anatomy, illustrate the scanning techniques, and emphasize the clinical relevance of the ankle/foot region.
Comparison of Night, Day and 24 h Motor Activity Data for the Classification of Depressive Episodes
Authors: Rodríguez-Ruiz Julieta G. , Galván-Tejada Carlos E. , Zanella-Calzada Laura A. , Celaya-Padilla José M. , Galván-Tejada Jorge I. , Gamboa-Rosales Hamurabi , Luna-García Huizilopoztli , Magallanes-Quintanar Rafael , Soto-Murillo Manuel A.
Published: March 2020

Major Depression Disease has been increasing in the last few years, affecting around 7 percent of the world population, but nowadays techniques to diagnose it are outdated and inefficient. Motor activity data in the last decade is presented as a better way to diagnose, treat and monitor patients suffering from this illness, this is achieved through the use of machine learning algorithms. Disturbances in the circadian rhythm of mental illness patients increase the effectiveness of the data mining process. In this paper, a comparison of motor activity data from the night, day and full day is carried out through a data mining process using the Random Forest classifier to identified depressive and non-depressive episodes. Data from Depressjon dataset is split into three different subsets and 24 features in time and frequency domain are extracted to select the best model to be used in the classification of depression episodes. The results showed that the best dataset and model to realize the classification of depressive episodes is the night motor activity data with 99.37% of sensitivity and 99.91% of specificity.
Design and Practical Stability of a New Class of Impulsive Fractional-Like Neural Networks
Authors: Stamov Gani , Stamova Ivanka , Martynyuk Anatoliy , Stamov Trayan
Published: March 2020

In this paper, a new class of impulsive neural networks with fractional-like derivatives is defined, and the practical stability properties of the solutions are investigated. The stability analysis exploits a new type of Lyapunov-like functions and their derivatives. Furthermore, the obtained results are applied to a bidirectional associative memory (BAM) neural network model with fractional-like derivatives. Some new results for the introduced neural network models with uncertain values of the parameters are also obtained.
Analysis of Social Media Impact on Opportunity Recognition. A Social Networks and Entrepreneurial Alertness Mixed Approach
Authors: Ceptureanu Sebastian Ion , Ceptureanu Eduard Gabriel , Cristescu Marian Pompiliu , Dhesi Gurjeet
Published: March 2020

This paper investigates the effects of social media on entrepreneurial opportunity recognition. Combining the internal and external approaches of opportunity recognition, the study analyzes how social media influences the entrepreneurs in discovering new entrepreneurial opportunities. Structural equation modeling was used in this study, using the variance-based partial least squares (PLS)–structural equation modeling (SEM), on a sample of 354 entrepreneurs. We concluded that social media directly and positively influences entrepreneurial opportunity recognition while entrepreneurial alertness (internal approach) and social networks (external approach) partially mediates its indirect effects on entrepreneurial opportunity recognition. The study contributes to the existing literature by bringing new insights into the entrepreneurial opportunity recognition process by focusing on a poorly represented factor in the literature, social media.
Social Media University Branding
Authors: Maresova Petra , Hruska Jan , Kuca Kamil
Published: March 2020

Globalization has increased the demands placed on higher education and increased competition among universities. In response, institutions of higher education have started to consider their online presence as a potential competitive advantage. The aim of this article is to analyze and compare Facebook activity and content created by the world’s top ten universities. The professional social media analytics tool Socialbakers is used to monitor activity and collect data for analysis. The world’s top ten universities are determined based on the Quacquarelli Symonds (QS) University Rankings. The study results are divided into four categories: an analysis of the number of fans, of content, of style, and of post promotion. All of the studied universities upload a post at least once per day. Based on the study results, selected posts could be examples of best practice and serve to inspire other educational institutions to improve their brand image and communication on social networks. Social media provide a large amount of detailed data concerning the behavior of students and other stakeholders and on the effectiveness of promotional campaigns. To use social media effectively, it is necessary to collect the available data and evaluate them to gain insight on which to base an appropriate social media strategy
Low-Power RTL Code Generation for Advanced CNN Algorithms toward Object Detection in Autonomous Vehicles
Authors: Kim Youngbae , Kim Heekyung , Yadav Nandakishor , Li Shuai , Choi Kyuwon Ken
Published: March 2020

In the implementation process of a convolution neural network (CNN)-based object detection system, the primary issues are power dissipation and limited throughput. Even though we utilize ultra-low power dissipation devices, the dynamic power dissipation issue will be difficult to resolve. During the operation of the CNN algorithm, there are several factors such as the heating problem generated from the massive computational complexity, the bottleneck generated in data transformation and by the limited bandwidth, and the power dissipation generated from redundant data access. This article proposes the low-power techniques, applies them to the CNN accelerator on the FPGA and ASIC design flow, and evaluates them on the Xilinx ZCU-102 FPGA SoC hardware platform and 45 nm technology for ASIC, respectively. Our proposed low-power techniques are applied at the register-transfer-level (RT-level), targeting FPGA and ASIC. In this article, we achieve up to a 53.21% power reduction in the ASIC implementation and saved 32.72% of the dynamic power dissipation in the FPGA implementation. This shows that our RTL low-power schemes have a powerful possibility of dynamic power reduction when applied to the FPGA design flow and ASIC design flow for the implementation of the CNN-based object detection system.
An Energy Logger for Kinetic-Powered Wrist-Wearable Systems
Authors: Manjarres Jose , Pardo Mauricio
Published: March 2020

Kinetic energy harvesting is a promising technology towards the development of alternative battery-charging schemes or even self-powered wearable devices that obtain their power supply from human motion. Although there are many developments with schemes that leverage piezoelectric materials and human motion to power devices especially from footsteps, some other body locations like the wrist still need assessment with piezoelectric generators to evaluate their potential of limitations. In this work, we present the results of logging the energy transference from a wrist-worn piezoelectric harvester to a battery in a wearable device. This system is the continuation of our previous work where we implemented the harvester with a resistive load previously tuned to obtain maximum power and assessed the energy harvested during physical activities. Now, we replace the linear load with a charge controller and a Li-ion battery in the same wearable set-up. These new conditions are not optimal for the piezoelectric generator but present a more realistic environment for the kinetic harvester and allows a more precise study of the feasibility of a self-powered system. Tests show that five minutes of activities that involve arm motion can provide between 1.75 mJ and 2.98 mJ of energy, which can represent between 3.6 seconds and 6.2 seconds of additional battery duration. Hence, these results provide an insight of the limitations and challenges remaining in the piezoelectric-based kinetic harvesting field for wearable devices.
Development of Enabling Technologies for Ku-Band Airborne SATCOM Phased-Arrays
Authors: Catalani Alfredo , Toso Giovanni , Angeletti Piero , Albertini Mario , Russo Pasquale
Published: March 2020

In the paper the development of a fully electronic transmit-receive phased-array antenna system in Ku-band for aircraft communications via satellite is presented. Particular emphasis has been placed in the improvement of the following key elements: a dual-polarization self-diplexing radiating element, a transmit/receive active module with full polarization agility based on a digital vector modulator and a SiGe multinode MMIC. The optimized antenna elements enable a significant improvement towards the realization of a future affordable commercial product for satellite communications.
Sensitive, Linear, Robust Current-To-Time Converter Circuit for Vehicle Automation Application
Authors: Yadav Nandakishor , Kim Youngbae , Alashi Mahmoud , Choi Kyuwon Ken
Published: March 2020

Voltage-to-time and current-to-time converters have been used in many recent works as a voltage-to-digital converter for artificial intelligence applications. In general, most of the previous designs use the current-starved technique or a capacitor-based delay unit, which is non-linear, expensive, and requires a large area. In this paper, we propose a highly linear current-to-digital converter. An optimization method is also proposed to generate the optimal converter design containing the smallest number of PMOS and sensitive circuits such as a differential amplifier. This enabled our design to be more stable and robust toward negative bias temperature instability (NBTI) and process variation. The proposed converter circuit implements the point-wise conversion from current-to-time, and it can be used directly for a variety of applications, such as analog-to-digital converters (ADC), used in built-in computational random access (C-RAM) memory. The conversion gain of the proposed circuit is 3.86 ms/A, which is 52 times greater than the conversion gains of state-of-the-art designs. Further, various time-to-digital converter (TDC) circuits are reviewed for the proposed current-to-time converter, and we recommend one circuit for a complete ADC design.
A Cloud-to-Edge Approach to Support Predictive Analytics in Robotics Industry
Authors: Panicucci Simone , Nikolakis Nikolaos , Cerquitelli Tania , Ventura Francesco , Proto Stefano , Macii Enrico , Makris Sotiris , Bowden David , Becker Paul , O’Mahony Niamh , Morabito Lucrezia , Napione Chiara , Marguglio Angelo , Coppo Guido , Andolina Salvatore
Published: March 2020

Data management and processing to enable predictive analytics in cyber physical systems holds the promise of creating insight over underlying processes, discovering anomalous behaviours and predicting imminent failures threatening a normal and smooth production process. In this context, proactive strategies can be adopted, as enabled by predictive analytics. Predictive analytics in turn can make a shift in traditional maintenance approaches to more effective optimising their cost and transforming maintenance from a necessary evil to a strategic business factor. Empowered by the aforementioned points, this paper discusses a novel methodology for remaining useful life (RUL) estimation enabling predictive maintenance of industrial equipment using partial knowledge over its degradation function and the parameters that are affecting it. Moreover, the design and prototype implementation of a plug-n-play end-to-end cloud architecture, supporting predictive maintenance of industrial equipment is presented integrating the aforementioned concept as a service. This is achieved by integrating edge gateways, data stores at both the edge and the cloud, and various applications, such as predictive analytics, visualization and scheduling, integrated as services in the cloud system. The proposed approach has been implemented into a prototype and tested in an industrial use case related to the maintenance of a robotic arm. Obtained results show the effectiveness and the efficiency of the proposed methodology in supporting predictive analytics in the era of Industry 4.0.
Design and Control of a DC Collection System for Modular-Based Direct Electromechanical Drive Turbines in High Voltage Direct Current Transmission
Authors: Bin Mohamad Saifuddin Muhammad Ramadan , Ramasamy Thaiyal Naayagi , Qi Tong Wesley Poh
Published: March 2020

In response to an increasing demand for offshore turbine-based technology installations, this paper proposes to design a DC collection system for multi-connected direct drive turbines. Using tidal stream farm as the testbed model, inverter design and turbine control features were modelled in compliance with high voltage ride-through capabilities that operate in isochronous mode suggested by IEEE1547-2018. The aim of the paper is twofold. Firstly, operation analyses in engaging a single-stage impedance source inverter as an AC-link busbar aggregator to pilot a parallel-connected electromechanical drive system. It uses a closed-loop voltage controller to secure voltage-active power (Volt/Watt) dynamics in correspondence with turbine’s arbitrary output voltage level. It also aspires to truncate active rectification stages at generation-side as opposed to a traditional back-to-back converter. Secondly, a proposition for a torque-controlled blade pitching system is modelled to render a close to maximum power point tracking using blade elevation and mechanical speed manipulations. The reserve active power generation aids with compensating an over-voltage crisis as a substitute for typical reactive power absorption. The proposed Testbed system was modelled in PSCAD, adopting industrial related specifications and real-time ocean current profiles for HVDC transmission operations. Analytical results have shown a positive performance index and transient responses at respective tidal steam turbine clusters that observe fault ride-through criterion despite assertive operating conditions.
Low-Power CMOS Complex Bandpass Filter with Passband Flatness Tunability
Authors: Kim Jungah , Lee Yongho , Chang Shinil , Shin Hyunchol
Published: March 2020

We present a low-power CMOS active-resistance-capacitance (active-RC) complex bandpass filter (BPF) with tunable gain, bandwidth, center frequency, quality factor, and passband flatness for Bluetooth applications. A transfer function analysis for a cross-coupled Tow-Thomas biquad structure is presented to prove that the flatness profile of the passband gain can be effectively controlled by independently tuning two cross-coupling resistors. The proposed biquad-based complex BPF was employed to realize a fourth-order baseband analog processor for a low intermediate frequency (low-IF) RF receiver. The baseband analog processor was composed of two complex biquad filters and three first-order variable-gain amplifiers. It was fabricated in a 65-nm RF CMOS and achieved wide tuning capabilities, such as a gain of −15.6 to 50.6 dB, a bandwidth of 1.4–3.9 MHz, a center frequency of 1.5–4.1 MHz, and a passband flatness of −1 to 1 dB. It also achieved an image rejection ratio of 40.3–53.3 dB across the entire gain tuning range. It consumed 1.4 mA from a 1 V supply and occupied an area of 0.19 mm2 on the silicon substrate. The implementation results prove that the proposed complex BPF was able to effectively enhance the signal processing performances through the flexible and wide-range tunability of the passband flatness, as well as that of the gain, bandwidth, center frequency, and quality factor.
Role of m6A in Embryonic Stem Cell Differentiation and in Gametogenesis
Authors: Lasman Lior , Hanna Jacob H , Novershtern Noa
Published: March 2020

The rising field of RNA modifications is stimulating massive research nowadays. m6A, the most abundant mRNA modification is highly conserved during evolution. Through the last decade, the essential components of this dynamic mRNA modification machinery were found and classified into writer, eraser and reader proteins. m6A modification is now known to take part in diverse biological processes such as embryonic development, cell circadian rhythms and cancer stem cell proliferation. In addition, there is already firm evidence for the importance of m6A modification in stem cell differentiation and gametogenesis, both in males and females. This review attempts to summarize the important results of recent years studying the mechanism underlying stem cell differentiation and gametogenesis processes.
Full-Span Flying Wing Wind Tunnel Test: A Body Freedom Flutter Study
Authors: Shi Pengtao , Liu Jihai , Gu Yingsong , Yang Zhichun , Marzocca Pier
Published: March 2020

Aiming at the experimental test of the body freedom flutter for modern high aspect ratio flexible flying wing, this paper conducts a body freedom flutter wind tunnel test on a full-span flying wing flutter model. The research content is summarized as follows: (1) The full-span finite element model and aeroelastic model of an unmanned aerial vehicle for body freedom flutter wind tunnel test are established, and the structural dynamics and flutter characteristics of this vehicle are obtained through theoretical analysis. (2) Based on the preliminary theoretical analysis results, the design and manufacturing of this vehicle are completed, and the structural dynamic characteristics of the vehicle are identified through ground vibration test. Finally, the theoretical analysis model is updated and the corresponding flutter characteristics are obtained. (3) A novel quasi-free flying suspension system capable of releasing pitch, plunge and yaw degrees of freedom is designed and implemented in the wind tunnel flutter test. The influence of the nose mass balance on the flutter results is explored. The study shows that: (1) The test vehicle can exhibit body freedom flutter at low airspeeds, and the obtained flutter speed and damping characteristics are favorable for conducting the body freedom flutter wind tunnel test. (2) The designed suspension system can effectively release the degrees of freedom of pitch, plunge, and yaw. The flutter speed measured in the wind tunnel test is 9.72 m/s, and the flutter frequency is 2.18 Hz, which agree well with the theoretical results (with flutter speed of 9.49 m/s and flutter frequency of 2.03 Hz). (3) With the increasing of the mass balance at the nose, critical speed of body freedom flutter rises up and the flutter frequency gradually decreases, which also agree well with corresponding theoretical results.
Writing Lifestories: A Methodology Introducing Students to Multicultural Education Utilizing Creative Writing and Genealogy
Authors: Cross Paulette T.
Published: March 2020

In this article, the author describes how she used a university course book assignment to produce a family history book to: (1) Raise consciousness and deepen understandings of other cultures, (2) assist students’ understanding of how intersecting cultures become part of the complex American cultural landscape, and (3) introduce students to research utilizing genealogical tools. The assignment aims to provide freshmen and preservice teacher education students an opportunity to recover personal memories and retell family stories, meld personal fragments into context by researching the historical and cultural backgrounds of their ancestors and produce a work that captures the interior life of a culture where each of us came. This calls for using “historical memory” to recover personal memories and retell family stories. Lastly, the knowledge gained from the Writing Lifestories: Exploring Cultural Heritages’ (2019) course will help students understand and heighten an awareness of multiculturalism/multicultural education through creative writing and immersion into research.
Estimation of Crop Water Deficit in Lower Bari Doab, Pakistan Using Reflection-Based Crop Coefficient
Authors: Javed Muhammad Asif , Rashid Ahmad Sajid , Awan Wakas Karim , Munir Bilal Ahmed
Published: March 2020

There is a global realization in all governmental setups of the need to provoke the efficient appraisal of crop water budgeting in order to manage water resources efficiently. This study aims to use the satellite remote sensing techniques to determine the water deficit in the crop rich Lower Bari Doab Canal (LBDC) command area. Crop classification was performed using multi-temporal NDVI profiles of Landsat-8 imagery by distinguishing the crop cycles based on reflectance curves. The reflectance-based crop coefficients (Kc) were derived by linear regression between normalized difference vegetation index (NDVI) cycles of the Moderate Resolution Imaging Spectroradiometer (MODIS) MOD13Q1 and MYD13Q1 products and Food and Agriculture Organization (FAO) defined crop coefficients. A MODIS 250 m NDVI product of the last 10 years (2004-2013) was used to identify the best performing crop cycle using Fourier filter method. The meteorological parameters including rainfall and temperature substantiated the reference evapotranspiration (ET0) calculated using the Hargreaves method. The difference of potential ET and actual ET, derived from the reflectance-based Kc calculated using reference NDVI and current NDVI, generates the water deficit. Results depict the strong correlation between ET, temperature and rainfall, as the regions having maximum temperature resulted in high ET and low rainfall and vice versa. The derived Kc values were observed to be accurate when compared with the crop calendar. Results revealed maximum water deficit at middle stage of the crops, which were observed to be particularly higher at the tail of the canal command. Moreover, results also depicted that kharif (summer) crops suffer higher deficit in comparison to rabi (winter) crops due to higher ET demand caused by higher temperature. Results of the research can be utilized for rational allocation of canal supplies and guiding farmers towards usage of alternate sources to avoid crop water stress.
Online Education Program in Operational Meteorology and a Case Study about a Product for Decision Making
Authors: Garbanzo-Salas Marcial , Jimenez-Robles Diana
Published: March 2020

An online program developed at the University of Costa Rica provides the professionals working in meteorology a new way to pursue graduate level degrees. The focus of this graduate program is Operational Meteorology and the students need to complete the research and development process of an operational product to graduate. The products created during the program are a solution to operational institutions in need of innovation and can later be incorporated into institutional activities including advisories, warnings and emergency management. A case study included here shows an example of the need that led to the product, the methodologies used for the development and the final operational product created.
Accessibility in Web Development Courses: A Case Study
Authors: Ferati Mexhid , Vogel Bahtijar
Published: March 2020

Web accessibility is becoming a relevant topic with an increased number of people with disabilities and the elderly using the web. Numerous legislations are being passed that require the web to be universally accessible to all people, regardless of their abilities and age. Despite this trend, university curricula still teach traditional web development without addressing accessibility as a topic. To investigate this matter closely, we studied the syllabi of web development courses at one university to evaluate whether the topic of accessibility was taught there. Additionally, we conducted a survey with nineteen students who were enrolled in a web development course, and we interviewed three lecturers from the same university. Our findings suggest that the topic of accessibility is not covered in web development courses, although both students and lecturers think that it should. This generates lack of competence in accessibility. The findings also confirm the finding of previous studies that, among web developers, there is a low familiarity with accessibility guidelines and policies. An interesting finding we uncovered was that gender affects the motivation to learn about accessibility. Females were driven by personal reasons, which we attribute to females having an increased sense of empathy. Finally, our participants were divided in their opinions whether accessibility contributes to usability.
Gene Expression Profiling Indicated Diverse Functions and Characteristics of Core Genes in Pea Aphid
Authors: Tian Ruizheng , Huang Yixiao , Balakrishnan Balachandar , Chen Maohua
Published: March 2020

The pea aphid is a global insect pest, and variable phenotypes can be produced by pea aphids in the same genotype in response to changes in external environmental factors. However, detailed dynamic gene regulation networks and the core markers involved in different biological processes of pea aphids have not yet been reported. In this study, we obtained the published genomic and transcriptomic data, and performed transcriptome profiling of five pea aphid morphs (winged asexual female, wingless asexual female, wingless sexual female, winged male and wingless male) from each of three pea aphid genotypes, i.e., the transcriptomes from a total of 15 types of pea aphids were analyzed and the type-specific expression of genes in five different morphs was identified. The expression profiling was verified by quantitative real-time PCR (qPCR) analysis. Moreover, we determined the expression features and co-expression networks of highly variable genes. We also used the ARACNe method to obtain 263 core genes related to different biological pathways. Additionally, eight of the identified genes were aligned with transcription factor families, indicating that they act as transcription factors and regulate downstream genes. Furthermore, we found reliable markers using random forest methodology to distinguish different morphs of pea aphids. Our study provides a systematic and comprehensive approach for analyzing the core genes that may play important roles in a multitude of biological processes from the insect transcriptomes.
Analysis of Dynamical Heat Conductivity of the Reservoir and Fluid Evacuation Zone on the Gas Condensate Well Flow Rate
Authors: Anzian Kouadio Fabrice , Fyk Mykhailo Illich , Bassam Al-Sultan Mohammed , Abbood Mohammed Khaleel , Abdullatif Haval Mohammed , Shapchenko Yevhen Alexender
Published: March 2020

This study shows that the thermal conductivity of the rock borehole adjacent to the wells varies depending on the operation of the well. This is due to the fact that the actual temperature and temperature difference affect the humidity and other thermal properties of the rocks, which in turn affect the heat transfer coefficient across the section between the moving gas and the rocks. The static temperature field of primitive geothermal gradients acquires changes in a dynamic form. Theoretical consideration of changes in the thermal conductivity of rocks near the face and the wells is proposed to improve the prediction of gas condensate wells production. The result is achieved by introducing the specified equations of the thermal energy balance in the radial filtration and lifting of well products, which contain the coefficients of heat exchange and throttling. The refinement bias estimation of the 10%–15% level of gas condensate well extraction is shown using proposed methodological approach to relatively well-known (traditional in the field development practice) methods for estimating the extraction of a “medium well” from a particular oil and gas field evaluation. The results of this work demonstrate important scientific, applied, educational and methodological significance of using the methodology presented by the authors.
Baseline Chest Computed Tomography as Standard of Care in High-Risk Hematology Patients
Authors: Stemler Jannik , Bruns Caroline , Mellinghoff Sibylle C. , Alakel Nael , Akan Hamdi , Ananda-Rajah Michelle , Auberger Jutta , Bojko Peter , Chandrasekar Pranatharthi H. , Chayakulkeeree Methee , Cozzi José A. , de Kort Elizabeth A. , Groll Andreas H. , Heath Christopher H. , Henze Larissa , Hernandez Jimenez Marcos , Kanj Souha S. , Khanna Nina , Koldehoff Michael , Lee Dong-Gun , Mager Alina , Marchesi Francesco , Martino-Bufarull Rodrigo , Nucci Marcio , Oksi Jarmo , Pagano Livio , Phillips Bob , Prattes Juergen , Pyrpasopoulou Athina , Rabitsch Werner , Schalk Enrico , Schmidt-Hieber Martin , Sidharthan Neeraj , Soler-Palacín Pere , Stern Anat , Weinbergerová Barbora , El Zakhem Aline , Cornely Oliver A. , Koehler Philipp
Published: March 2020

Baseline chest computed tomography (BCT) in high-risk hematology patients allows for the early diagnosis of invasive pulmonary aspergillosis (IPA). The distribution of BCT implementation in hematology departments and impact on outcome is unknown. A web-based questionnaire was designed. International scientific bodies were invited. The estimated numbers of annually treated hematology patients, chest imaging timepoints and techniques, IPA rates, and follow-up imaging were assessed. In total, 142 physicians from 43 countries participated. The specialties included infectious diseases (n = 69; 49%), hematology (n = 68; 48%), and others (n = 41; 29%). BCT was performed in 57% (n = 54) of 92 hospitals. Upon the diagnosis of malignancy or admission, 48% and 24% performed BCT, respectively, and X-ray was performed in 48% and 69%, respectively. BCT was more often used in hematopoietic cell transplantation and in relapsed acute leukemia. European centers performed BCT in 59% and non-European centers in 53%. Median estimated IPA rate was 8% and did not differ between BCT (9%; IQR 5–15%) and non-BCT centers (7%; IQR 5–10%) (p = 0.69). Follow-up computed tomography (CT) for IPA was performed in 98% (n = 90) of centers. In high-risk hematology patients, baseline CT is becoming a standard-of-care. Chest X-ray, while inferior, is still widely used. Randomized, controlled trials are needed to investigate the impact of BCT on patient outcome.
Suspending Classes Without Stopping Learning: China’s Education Emergency Management Policy in the COVID-19 Outbreak
Authors: Zhang Wunong , Wang Yuxin , Yang Lili , Wang Chuanyi
Published: March 2020

Against the backdrop of the COVID-19 outbreak, an emergency policy initiative called “Suspending Classes Without Stopping Learning” was launched by the Chinese government to continue teaching activities as schools across the country were closed to contain the virus. However, there is ambiguity and disagreement about what to teach, how to teach, the workload of teachers and students, the teaching environment, and the implications for education equity. Possible difficulties that the policy faces include: the weakness of the online teaching infrastructure, the inexperience of teachers (including unequal learning outcomes caused by teachers’ varied experience), the information gap, the complex environment at home, and so forth. To tackle the problems, we suggest that the government needs to further promote the construction of the educational information superhighway, consider equipping teachers and students with standardized home-based teaching/learning equipment, conduct online teacher training, include the development of massive online education in the national strategic plan, and support academic research into online education, especially education to help students with online learning difficulties.