bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of SMES system with non‐linear dynamic evolution control approach for pulsed power load compensation
Authors: Penthia Trilochan , Panda Anup Kumar , Patnaik Nishant , Mohanty Pratap Ranjan
Published: February 2020

Superconducting magnetic energy storage (SMES) system is one of the efficient pulsed power compensators. Its response to the load fluctuations is faster and competent. This study proposes a non‐linear dynamic evolution control (NDEC) approach for SMES system. The control approach is implemented to regulate the error of three‐phase compensating current and DC‐link voltage. The control functions required for voltage source inverter (VSI) and bi‐directional DC–DC converter of the SMES system are derived using the NDEC control approach. A proportional–integral (PI) controller is replaced by the NDEC in the inner loop of a traditional pulse‐width‐modulation control strategy of VSI for the quick response and effective energy exchange. The elementary idea of implementing NDEC is to govern the system dynamics by maintaining a zero‐error state irrespective of load uncertainties quickly. Detrimental high rating stress on the system due to pulsed power load is substantially reduced with the proposed NDEC strategy. Source current is maintained almost balanced and harmonic‐free in order to ensure a quality and reliable supply to surrounding loads. The variation in source current is drastically reduced from 260 to 6% using the proposed system. Moreover, a comparative study between PI and NDEC‐based control scheme is presented using MATLAB simulation and experimental results.
Barium titanate/polydimethylsiloxane nano/microcomposites fabrication, morphology, dielectric response and functionality
Authors: Patsidis Anastasios C.
Published: February 2020

Polymer matrix composites with embedded ferroelectric and/or piezoelectric particles, constitute a novel and interesting class of engineering materials. The incorporation of ferroelectric and/or piezoelectric particles within a polymer matrix is expected to add functionality to the resulting composite, due to the variation of polarisation of the ceramic particles with temperature. In this work, an elastomeric matrix such as polydimethylsiloxane and BaTiO3 nano and microparticles were used for the fabrication of composites at various concentrations and sizes of the reinforcing phase. Morphological and structural characteristics were investigated via scanning electron microscopy images and X‐ray diffraction patterns. The dielectric behaviour of all fabricated specimens was investigated via broadband dielectric spectroscopy, in a wide frequency (10−1 Hz–10 MHz) and temperature (30–200°C) range. In the dielectric spectra, two relaxation processes were detected, namely cold crystallisation and interfacial polarisation. Values of dielectric permittivity enhance with filler content, and particles’ size, while diminishes significantly with frequency. Finally, the ability of the prepared systems to store energy was examined by calculating their energy density. The higher energy‐storing efficiency is exhibited by the micro‐BaTiO3 reinforced composites, while functional behaviour is induced via the thermally activated structural changes of ferroelectric particles.
The effect of artificial support material existence on removal of organic and nutrient in laboratory scale using plug flow reactor (PFR)
Authors: Aphirta Sarah , Soewondo Prayatni , Maisa Zakiyya Nida , Wulandari Putri Dyah , Setiani Muntalif Barti
Published: February 2020

Artificial support material was examined to determine the removal capacity of organic pollutants and nutrients on laboratory scale using PFR system. The experiment was performed using artificial water with similar characteristics to Cikapayang River in three PFRs of 10.78 L. The PFRs were made of PVC pipes filled with an inert chemical substrate as an artificial support material. The process of pollutants removal in the PFR relies on a biological layer (biofilm) grown on the surface of the material support. Three type of C:N:P ratio used in this study were 30:15:1, 75:25:2, and 180:35:3. The results showed that the maximum removal efficiency of TSS, TN, TP, and COD in the preliminary tests were 85%, 87%, 71% and 79%, respectively. Moreover, the maximum water absorption capacity result was up to 30.8%. Organic substrate removal rate compared with first order and Strover-Kincannon substrate removal models prediction. The best fit model for this experiment was Stover-Kincannon model, with the average correlation coefficient up to 90% for all of the three reactors. SEM analysis shown that the microorganisms shape is coccus with the average size of 5 µm.
Estimating Energy Consumption and Cost for the Electrocoagulation of Arsenic-laden Water (ECAR) Using Iron Electrodes
Authors: Balares Kathleen Louise , Nuevo Joniel , Chiong Meliton , Macasieb Reygie , Resurreccion Augustus , Orozco Christian
Published: February 2020

In some areas in Pampanga, arsenic concentration from handpumps reaches up to 300 μg/L, 10 times higher than the safe limit for drinking water. An efficient way of reducing elevated arsenic concentration is through electrocoagulation (EC) process with the use of iron electrodes. However due to several factors, the efficiency of the technique is decreased. This study focuses on determining the energy consumption and cost through time. The cost per cycle was estimated through the power consumption and projecting its growth with time. One 600 L cycle costs around $0.60 to $1.10 which is approximately $0.001 to $0.002 per liter of water. This value increases through each cycle until half of the electrode is consumed (500 cycles) and is to be replaced. The current processing time was set at 30 mins, charge dosage of 150 C/L, applied current of 16.67 mA, and an electrode area of 6.6 cm2. One factor examined which may have caused the increase is the formation of passivation layer on the electrode surface. It was described using linear sweep voltammetry (LSV) and Tafel extrapolation method. The resistance due to charge transfer was determined to be increasing per cycle.
Bioregeneration of saturated natural mordenite to reduce iron and manganese in groundwater
Authors: Noor Rifka , Septiyani Elda , Zevi Yuniati , Arifianingsih Nur Novilina
Published: February 2020

Significant improvement of technologies was developed to remove iron and manganese contamination from ground water. One of the technologies is the use of adsorbents but, recycling of used adsorbents is little to be done. Only a few researchers reported studies that highlighted on recovery of adsorbent through biological processes. In this study, bio-regeneration chosen as a technical approach to reduce the rate of waste generation from the saturated mordenite (adsorbent). The principle of bio-regeneration adopted the mechanism of desorption after the use of adsorbents by empowering single culture of microorganism. To determine its capacity, activated minerals mordenite were used to treat water containing 2.29 ppm of Iron and 2.47 ppm of manganese for the first stage (Pre bio-regeneration). This artificial iron and manganese contaminated solution was used as a representation of ground water in Bandung area. The reactor used have continuous stream with up-flow direction. Iron and manganese removal efficiency respectively in the 1st stage of adsorption (before bio-regeneration process) reaches 95% and 97%. After the 72 hour submergence process by cultivated Thiobacillus ferooxidan, ability of the adsorbent still fulfil the drinking water quality standard in Minister of Health Regulation No. 492 of 2010. The removal efficiency reached 85% for iron but not suitable for manganese which only reached 30% of removal. This bio-regeneration can be applied as much as 2 times rounds.
Performance of Bioplant for Municipal Solid Waste at Jatinangor Campus of Institut Teknologi Bandung
Authors: Chaerul Mochammad
Published: February 2020

Although Law No. 18 year of 2018 has mandated recycling to be prioritized in solid waste management, the municipality intend to collect and to dump the waste directly to landfill. By cooperating with National Gas Company (PT. PGN), bioplant was constructed at area of 200 m2 and operated at Jatinangor Campus of Institut Teknologi Bandung to treat organic waste generated from the campus and traditional market near the campus. The study aims to evaluate the performance of the bioplant in term of biogas generation and composition during the pilot project. Main treatment at the bioplant is anaerobic digestion (AD) using two units with single-stage and wet fermentation. Organic waste as feeding had 62%, 61% of water and volatile contents, respectively. Carbon organic and total Nitrogen contributed 8.19% and 0.22%, respectively. 200 kg of the organic waste daily was mixed with ratio of 1:1 with water. Total volume biogas generated daily from 2 units of AD was 2.1 m3 with composition of 45%, 15%, and 10% of CH4, CO2 and O2, respectively. Due to the waste reduction at source, various potential negative impacts due to open dumping commonly operated at landfill site in Indonesia could be avoided.
Role of Scientific Evidence in the Adjudication of Dispute for Restoration of Burned Forest and Land
Authors: Aminudin Cecep , Fakhriah Efa Laela , Nurlinda Ida , Ikhwansyah Isis
Published: February 2020

One of the objectives of the adjudication of forest and land fire dispute is to restore the burned forests and land. However, evidencing aspect of forest and land fire cases in the judicial settlement is often challenging and the scientific evidence is sought. This normative legal research analyses court verdicts in a forest and land fire case qualitatively. It aims to describes the role of scientific evidence to the proof process in the adjudication that lead to the court verdict for environmental recovery of burned forests and land. Scientific evidence in the form of scientific studies and expert opinion admitted by the court has a role in proving land and forest fire occurrence, environmental damage and loss, and the causality element of the case.
The Mixing Speed Effect and Mass of Adsorbent On Copper (Cu) Removal from Wastewater by Water Hyacinth Leaves
Authors: Oktaviyana Lussa Mala , Wijayanti Asih , Ayu Kusumadewi Riana , Hadisoebroto Rositayanti
Published: February 2020

This study aims to determine the role of water hyacinth leaves powder on wastewater adsorbed from Cu ion, which is one of the metals responsible for environmental pollution and analyzed using AAS. Cu-wastewater was conducted in bathes and used to optimized the sorption at 250 ml, with 10 grams of water hyacinth leaves adsorbents added at speeds of 100, 150, 200 rpm, with contact times arrangement of 30, 60, 90 minutes. A maximum adsorption rate of 10 grams at a maximum speed of 100rpm, led to a removal efficiency of 98.19% and 60 minutes contact time. The equilibrium data utilized was properly represented in the Freundlich adsorption isotherm model to analyze the mechanism using R2≈1. In addition, Cu adsorption kinetic models were analyzed using the pseudo-second-order model at an adsorption rate of R2≈1. The result showed that the Cu-wastewater used to activate the water hyacinth leaves powder was highly effective for the treatment.
Flood mapping under an extreme event in a large shallow lake influenced by flood pulse in Southeast Asia
Authors: Siev Sokly , Ann Vannak , Nakamura Takashi , Fujii Hideto , Yoshimura Chihiro
Published: February 2020

Tonle Sap Lake (TSL) in Cambodia is the largest shallow lake in Southeast Asia. Influenced by flood pulse system of the Mekong River, TSL provides diverse benefits including ecosystem services, ecological functioning, and flood water storage in the floodplains. However, extreme events (e.g., flooding) due to rising water level caused by dam break and/or heavy rainfall in the Mekong River Basin could threaten the ecosystems of the lake, community health and economic growth in the region. Flood mapping under such extreme event could be informative in the flood risk and emergency management. In this study, we aim to develop a flood risk boundary map in TSL using an existing 2D hydrodynamic model (Caesar-Lisflood, CL) with rising water levels estimated by Gumbel distribution. As a result, the extreme water level of 1% chance (or 100-year flood return period) exceeding the annual maximum water level at Prek Kdam station was approximately 11.38 m resulting in the largest inundation area of 15193 km2. Overall, the employed method and flood risk mapping are useful for the decision makers to manage flood risks and emergency in the lake. This is to anticipate the consequences of a possible rising water level by an extreme event.
Quantification of Environmental Flow Requirement for some Rivers in West Java
Authors: Hatmoko Waluyo , Levina  , Radhika  , Amirwandi  , Rendy
Published: February 2020

Sustainable Development Goal (SDG). Water management is making a balance between water for livelihood and water as a resource. Environmental Flow Requirement (EFR) is water conservation, on the side of the water for livelihood, to sustain the river ecosystem. In Indonesia, the common quantification of EFR is dependable flow Q95%. However, there are alternative quantities: a) Guideline of irrigation states that 5% from the available water in the river is for environmental purposes; b) Adoption of the Tennant Method of using 10% of the mean flow; and recently Food and Agriculture Organization (FAO) in the framework of SDG proposed that in Java Island the EFR is from 40% to 50% of the mean annual flow. This paper discusses several ways of quantification of the EFR in Indonesia, and apply the different EFR quantities to Citarum, Cimanuk, and Cimandiri Rivers in West Java. It is concluded that EFR quantity according to FAO that might be suitable for the rivers in the pristine catchments in the southern part of West Java is too high for the rivers in the northern part of West Java which is heavily populated and maturely developed. Furthermore, the dependable flow of Q95% is found to be close to the quantity of FAO, but in the dry season, Q95% is more suitable. It is recommended using a modified FAO that combine with Q95% during the dry season.
Fate and spatial distribution of Pb, Cd, Cu and Zn in the water column and in the surface sediment of Indonesian Estuary (Citarum River Estuary)
Authors: Fahimah Nurul , Oginawati Katharina , Suharyanto
Published: February 2020

The Citarum River Estuary is an area where mixing among seawater and freshwater occurs since directly connected with the Java Sea. The different condition in estuary will affect heavy metal concentrations in the dissolved phase and suspended/deposited in sediment phase. In this study, fates and distributions from Pb, Cd, Cu and Zn were analyzed along 2 km from estuary mouth. Samples were analyzed by Flame AAS. The study began with water/sediment quality assessments, and fate and distribution analyses with Adsorption Capacity Indices (ACI), Dissolved Transport Indice (DTI), Koc, Kow, spatial distribution in water (3D) and sediment (2D) using MATLAB, and statistical analysis (ANOVA/Kruskal-Wallis). In conclusion, heavy metals sequence from the highest pollution level in water were: Zn > Pb > Cu > Cd, and in sediment were: Cd > Pb > Zn > Cu. Pb, Cd, Cu, and Zn had a tendency to be in sediment compared to water (ACI = 99.69% – 99.89%; DTI = 0.109% – 0.309%), slightly mobile (log Koc= 3.11 – 3.58), and hydrophobic (log Kow= 3.35 – 3.87). Pb and Cd showed significantly different concentrations in water columns (surface/midst/base) (p<0.05), in contrast to Cu and Zn. Pb, Cd, Cu, and Zn had insignificant concentration difference based on zone division from estuary mouth, both in water and sediment.
One-Dimensional Pollutant Transport Modelling of Cadmium (Cd), Chromium (Cr) and Lead (Pb) in Saguling Reservoir
Authors: Gede Adi Wiguna Sudiartha , Katharina Oginawati , Asep Sofyan , Ardiwinata  , Asep Kurnia , Sukarjo  , Cici Handayani , Sulaeman
Published: February 2020

The existing conditions of the Saguling Reservoir are reported to have suffered severe heavy metal pollution due to the presence of wastewater inputs from various types of industries flowing into Citarum River and then accumulating in the Saguling Reservoir. From the results of calibration tests of heavy metal models on water using the Root Mean Square Error (RMSE) analysis and Relative Error (RE) analysis, obtained dispersion coefficients on Cadmium, Chromium, and Lead metals sequentially 1 m2 / second (with RMSE 0,00515 and 34% relative error); 1 m2 / second (with RMSE 0.00595 and relative error 26%); and 2.5 m2 / second (with RMSE 0.028205 and relative error 41.25%) which shows that the model has good capability to simulate the concentration of heavy metals approaching the actual data both in the dry and wet seasons. From the results of the verification test models of concentration of cadmium, lead and chromium in sediments using the Root Mean Square Error (RMSE) analysis and Relative Error (RE) analysis, obtained sequentially 18.53 and 77%; 10.43 and 47.15%; 2.789 and 33%. Error values in sediment concentrations are quite large because of the difficulty of making assumptions that are close to natural conditions.
Solar pond as a low grade energy source for water desalination and power generation: a short review
Authors: AL-Musawi Osamah A.H. , Khadom Anees A. , Manhood Hammed B. , Mahdi Mustafa S.
Published: February 2020

Water and energy are thoroughly linked: water is required to generate, transfer, and use the lot characteristics of energy; and energy is demanded to extract, treat, and distribute water. Shortage in clean water deems as the main challenge facing the world as a result of the escalating in the energy consumption required for desalinating the sea/brackish water which increases costs and provokes on the marine life and environment due to the high concentrate solute produced from desalination plants. Solar pond is a reservoir of water with different salt concentration implements to gather and store the incident solar energy which it can be employed later on in different thermal energy applications, such as industrialized heating process, electricity power generation, farming crop drying and cooling of houses. In this paper a short but concentrated review of the literatures that dealt with the implemented of the solar pond to illustrate succinctly the historical background for the solar ponds as well as the most word-wide established solar ponds. In addition to the theoretical background of heat and mass transfer which governed the solar pond operation is presented and discussed.
Endoscopic submucosal dissection with double clip and rubber band traction for residual or locally recurrent colonic lesions after previous endoscopic mucosal resection
Authors: Faller Julien , Jacques Jérémie , Oung Borathchakra , Legros Romain , Rivory Jérôme , Subtil Fabien , Saurin Jean-Christophe , Robinson Philip , Ponchon Thierry , Pioche Mathieu
Published: February 2020

Background Endoscopic submucosal dissection (ESD) of residual or locally recurrent (RLR) colonic lesions after previous endoscopic mucosal resection (EMR) is an attractive but challenging technique. The present study aimed to evaluate the effectiveness and safety of ESD with double clip and rubber band traction (DCT-ESD) of RLR colonic lesions.

Methods We retrospectively analyzed all consecutive DCT-ESD procedures for RLR colonic lesions (rectum excluded) performed in two French centers. The frequency of en bloc and R0 resections, procedure speed, additional surgery, and complications were evaluated. R0 resection was also used to investigate the learning curve.

Results Among the 53 resections, 49 (92.5 %) were performed en bloc and 42 (79.2 %) achieved R0. The median procedure speed was 21 mm2/min. There were four (7.5 %) intraoperative perforations and one delayed bleeding; these were successfully treated endoscopically. There was no salvage surgery for complications. The R0 rate increased from 16/26 (61.5 %) for the first 26 procedures to 26/27 (96.3 %, P = 0.002) for the last 27 procedures.

Conclusions DCT-ESD appears to be a safe and effective treatment for RLR colonic lesions after EMR.
Analysis of Correlation and Agreement between the Uroflowmetry and the International Prostate Symptom Score in Patients after retropubic Radical Prostatectomy: A Multicenter Prospective Study
Authors: Torres Lynda , Puerto Angie , Bravo Alejandra , Acuña Miguel , Sánchez Juan , Bejarano Olga , Peña Paula , Cataño Juan Guillermo
Published: February 2020

Objectives Patients undergoing retropubic radical prostatectomy (RRP) may suffer from lower urinary tract symptoms (LUTS). We aim to characterize LUTS and to evaluate the correlation and agreement between uroflowmetry and the International Prostate Symptom Score (IPSS) in patients after RRP in two reference centers.

Methods An observational multicenter prospective study was conducted between December 2015 and September 2016. Patients with at least 12-months of follow-up after RRP were included; these were evaluated with uroflowmetry and the IPSS.

Results A total of 90 patients were included. The mean follow-up was of 54.6 months (standard deviation [SD] = 27.52), and the mean age was 65 (SD = 6.85) years old. The mean IPSS was 7.41 (SD = 6.29), with 33.3% (n = 54) of the patients with moderate symptoms and 6.7% (n = 6) with severe symptoms. A total of 50% (n = 45) of the patients had normal uroflowmetry. Patients with an abnormal/equivocal result in the uroflowmetry had a mean of 9.31 (SD = 7.03) points in the IPSS versus 5.51 (SD = 4.82) in patients with a normal uroflowmetry result (p < 0.01). The level of agreement between mild versus moderate-to-severe LUTS and normal uroflowmetry versus abnormal/equivocal was 61.1% (k = 0.22, p = 0.04). We found that a score ≥ 10 in the IPSS had a level of agreement of 65.6% (k = 0.31, p = 0.0004).

Conclusions We consider that although the IPSS cannot replace uroflowmetry and vice versa, these tests are complementary and may be useful tools in the evaluation of patients with LUTS after RRP.
Transitional Cell Carcinoma of the Bladder in Pediatric Patients: Where Do We Stand?
Authors: Perez Jaime , Chavarriaga Julián , Peña Paula , Ramos Gustavo , Torres Lynda , Bravo Alejandra , Orrego Paola , Fernandez Nicolás
Published: February 2020

Introduction Transitional cell carcinoma of the bladder (TCCB) is uncommon in the pediatric population, and its etiology, natural history and epigenetics remain poorly understood. We aim to describe six cases of TCCB in pediatric patients and discuss the state of the art in the management and follow-up of the patients with this uncommon early presentation.

Methods The clinicopathological data of 6 patients with TCCB who underwent transurethral resection of bladder tumor (TURBT) were obtained from our institutional database. The patient data were collected retrospectively. A review of the literature was performed, and the most relevant and trending data were analyzed.

Results A total of 6 patients (4 female, 2 male) were treated at our institution between 2004 and 2019. The mean age of the sample was 12 years, and the presenting symptoms were macroscopic hematuria (3 cases), suprapubic pain (2 cases), and 1 case was an incidental finding during pelvic ultrasonography. The long-term follow-up (median follow-up of 61 months) did not reveal recurrence.

Conclusion Transitional cell carcinoma of the bladder rarely presents in the pediatric population. Genetic and epigenetic anomalies have been proposed as causes, as well as carcinogenic exposure. The reported cases tend to have a good prognosis, and most are non-invasive at the diagnosis. Follow-up protocols are still lacking, as well as molecular insights on tumor development and prognostic markers.
Tracheoesophageal Voice Prosthesis Use and Maintenance in Laryngectomees
Authors: Brook Itzhak , Goodman Joseph F
Published: February 2020

Tracheoesophageal speech is the most common voicing method used by laryngectomees. This method requires the installation of tracheoesophageal prosthesis (TEP), which requires continuous maintenance to achieve optimal speaking abilities and prevent fluid leakage from the esophagus to the trachea. The present manuscript describes the available types of TEPs, the procedures used to maintain them, the causes for their failure due to fluid leakage, and the methods used for their prevention. Knowledge and understanding of these issues can assist the otolaryngologist in caring for laryngectomees who use tracheoesophageal speech.
The Role of Allopregnanolone Levels in Traumatic Brain Injury in Children and Adults and the Correlation of Its Levels with Computerized Tomography Images of the Brain
Authors: Coskun Göker , Beceren Nesrin Gökben , Bedel Cihan
Published: February 2020

Aim Allopregnanolone (AP) is a steroid of progesterone origin and it can readily pass through the blood–brain barrier. The aim of this study was to determine the AP levels occurring after head trauma in children and adults and to compare these results to the findings observed in the computed tomography (CT) of the respective individuals.

Materials and Methods  This study was conducted in the period from April 2018 to December 2018 on 92 patients admitted with isolated head trauma and on 80 healthy individuals in similar gender and age groups. The age, gender, and Glasgow Coma Scores of the patients; the cause of the head trauma; and the findings from CT imaging were recorded.

Results The levels of AP were significantly lower in the head trauma patients both in the adult and pediatric groups compared with the healthy control groups of respective ages (p < 0.001). Furthermore, the levels of AP were significantly lower in both the pediatric and adult patients with identified pathologies in the CT images compared with their counterpart control groups (p < 0.001). In predicting an existing pathology in the CT, an AP level of > 138.5 was found to be 85.7% sensitive and 85.3% specific in the pediatric patients, and an AP level of >118.3 was 75% sensitive and 83.5% specific in the adult patients.

Conclusion The levels of AP in head trauma patients were reduced in both the pediatric and adult patients and these low levels increase the likelihood of detecting pathology in CT images.
A simple vacuum suitcase for enabling plasma facing component characterization in fusion devices
Authors: Maan A. , Kaita R. , Ostrowski E. T. , Majeski R. , Boyle D. P. , Donovan D. C. , Ellis R. A. , Koel B. E. , Biewer T. M.
Published: February 2020

We have demonstrated a vacuum suitcase to transport samples in vacuo to a surface analysis station for characterization of tokamak plasma facing components (PFCs). This technique enables surface analysis at powerful, dedicated stations that are not encumbered by design constraints imposed on them by a tokamak. The vacuum suitcase is an alternative solution to characterizing PFCs using diagnostics that are designed and built around a tokamak. The vacuum suitcase, called the Sample Exposure Probe (SEP), features mobile ultra-high vacuum pumping. Active pumping under high vacuum enables sample transfer between the Lithium Tokamak eXperiment-β (LTX-β) and a high resolution X-ray Photoelectron Spectroscopy (XPS) system that is situated close by. A thermocouple inserted in the back of the sample head measures heat flux from the plasma during exposure, and together with a button heater, allows the sample to match the LTX-β PFCs in high temperature operations. As vacuum conditions are better during transfer and analysis than in the tokamak, less contamination is introduced to the samples. XPS scans on a dedicated analysis station enable peak identification due to higher resolution and signal to noise ratio. A similar probe could be implemented for other fusion devices. The SEP is the first vacuum suitcase implementation for fusion applications that incorporates active pumping.
Elucidating plasma dynamics in Hasegawa–Wakatani turbulence by information geometry
Authors: Anderson Johan , Kim Eun-jin , Hnat Bogdan , Rafiq Tariq
Published: February 2020

The impact of adiabatic electrons on drift-wave turbulence, modeled by the Hasegawa–Wakatani equations, is studied using information length. Information length is a novel theoretical method for measuring distances between statistical states represented by different probability distribution functions (PDFs) along the path of a system and represents the total number of statistically different states that a system evolves through in time. Specifically, the time-dependent PDFs of turbulent fluctuations for a given adiabatic index A are computed. The changes in fluctuation statistics are then quantified in time by using information length. The numerical results provide time traces exhibiting intermittent plasma dynamics, and such behavior is identified by a rapid change in the information length. The effects of A are discussed.
Highly (001) oriented MnAl thin film fabricated on CoGa buffer layer
Authors: Oshima Daiki , Kato Takeshi , Iwata Satoshi
Published: February 2020

5 nm- and 15 nm-thick (001) oriented MnAl films were fabricated on CoGa buffer layers with various thermal treatments. The insertion of the CoGa layer was effective to obtain the square out-of-plane hysteresis loop even in the MnAl thickness of 5 nm. Highly (001) oriented MnAl film was obtained by depositing Mn and Al on CoGa at a substrate temperature of 200°C followed by annealing at 500°C. The perpendicular magnetic anisotropy was estimated to be 7.4±0.2 and 8.5±0.4 Merg/cc for 5 nm- and 15 nm-thick MnAl, respectively. Lower anisotropy in 5 nm-thick MnAl may be due to the interdiffusion between the MnAl and CoGa layers.
Metaheuristic optimization approach and computational study on advanced mathematical modeling of solar cell
Authors: Mallick Subha Prakash
Published: February 2020

A solar cell current usually depends on bandgap, carrier lifetime, diffusion length, diffusion constant, ideality factor, and so on. This article proposes a model that shows direct dependency of bandgap in the solar cell current equation. It is based on foundation principles satisfactory of a single junction being extended to multi-junction solar cell applications with different bandgaps. Different proven optimization techniques such as the Gauss–Newton optimization, Levenberg–Marquardt optimization, differential evolution algorithm, and whale optimization algorithm (WOA) were used for parameter extraction and optimization. To demonstrate the better optimization of model data with experimental data, further analysis of results was carried out on the basis of percentage deviation and error comparison. Complete comprehensive and comparative analysis of results of error and percentage deviation from different standard iterative optimization techniques proves the WOA as one of the best optimization techniques among all. As a result, the WOA offers a better optimal solution of model parameters with the best convergence of model data with the experimental data that shows the smallest possible value of error and minimum percentage deviation.
Theoretical analysis of two-layered electro-osmotic peristaltic flow of FENE-P fluid in an axisymmetric tube
Authors: Ali N. , Hussain S. , Ullah K.
Published: February 2020

This article presents the theoretical analysis of two-dimensional peristaltic transport of two-fluids in a flexible tube under the influence of electro-osmotic force. The flow domain is composed of two regions, namely, the core region and the peripheral region. The Newtonian and the FENE-P models are used to describe the rheology of fluids in the peripheral and the core regions, respectively. Governing flow equations corresponding to each region are developed under the assumption of long wavelength and low-Reynolds number. The interface between the two regions is computed numerically by employing a system of non-linear algebraic equations. The influence of relevant controlling parameters on pressure gradient, interface, trapping, and reflux is highlighted graphically and explained in detail. Special attention is given to estimate the effects of viscoelastic parameter of the core region fluid in the presence of electro-osmotic environment. Our investigation indicates an augmentation in the pressure loss at a zero volumetric flow rate with growing the viscoelastic and occlusion parameters. Moreover, trapping, reflux, and pumping efficiency are found to increase by increasing the electro-osmotic and viscoelastic parameters. The analysis presented here may be helpful in controlling the micro-vascular flow during the fractionation of blood into plasma (in the peripheral layer) and erythrocytes (core layer). This study may also have potential applications in areas such as electrophoresis, hematology, design, and improvement of bio-mimetic electro-osmotic pumps.
On reference solutions for ship waves
Authors: Gnevyshev Vladimir G. , Badulin Sergei I.
Published: February 2020

The classic problem of ship waves of infinitely small amplitudes is studied within the recently developed approach of reference solutions [V. G. Gnevyshev and S. I. Badulin, Moscow Univ. Phys. Bull. 72, 415 (2017)]. The evolution of narrow-banded Gaussian wavetrains of a finite volume is considered as an alternative to the conventional inherently point-wise tracking of wavetrains within the asymptotic methods of the stationary phase or the steepest descent. The approach allows for avoiding general problems of the methods: occurrence of singularities of wave fields. The non-singular solutions for a stationary ship wake are presented in an analytical form in terms of two key dimensionless quantities: the Froude number and the aspect ratio of the initial (boundary) domain of wave generation. Systems of transverse and diverging ship waves as well as amplitude and phase effects of their transformation can be analyzed separately within this approach for small Froude numbers. The essential role of dispersion of three-dimensional water waves is emphasized and detailed.
Defective HIV-1 proviruses produce viral proteins
Authors: Imamichi Hiromi , Smith Mindy , Adelsberger Joseph W. , Izumi Taisuke , Scrimieri Francesca , Sherman Brad T. , Rehm Catherine A. , Imamichi Tomozumi , Pau Alice , Catalfamo Marta , Fauci Anthony S. , Lane H. Clifford
Published: February 2020

HIV-1 proviruses persist in the CD4
+
T cells of HIV-infected individuals despite years of combination antiretroviral therapy (cART) with suppression of HIV-1 RNA levels <40 copies/mL. Greater than 95% of these proviruses detected in circulating peripheral blood mononuclear cells (PBMCs) are referred to as “defective” by virtue of having large internal deletions and lethal genetic mutations. As these defective proviruses are unable to encode intact and replication-competent viruses, they have long been thought of as biologically irrelevant “graveyard” of viruses with little significance to HIV-1 pathogenesis. Contrary to this notion, we have recently demonstrated that these defective proviruses are not silent, are capable of transcribing novel unspliced forms of HIV-RNA transcripts with competent open reading frames (ORFs), and can be found in the peripheral blood CD4
+
T cells of patients at all stages of HIV-1 infection. In the present study, by an approach of combining serial dilutions of CD4
+
T cells and T cell–cloning technologies, we are able to demonstrate that defective proviruses that persist in HIV-infected individuals during suppressive cART are translationally competent and produce the HIV-1 Gag and Nef proteins. The HIV-RNA transcripts expressed from these defective proviruses may trigger an element of innate immunity. Likewise, the viral proteins coded in the defective proviruses may form extracellular virus-like particles and may trigger immune responses. The persistent production of HIV-1 proteins in the absence of viral replication helps explain persistent immune activation despite HIV-1 levels below detection, and also presents new challenges to HIV-1 eradication.
Exploring the interplay between fibrillization and amorphous aggregation channels on the energy landscapes of tau repeat isoforms
Authors: Chen Xun , Chen Mingchen , Schafer Nicholas P. , Wolynes Peter G.
Published: February 2020

Filaments made up of different isoforms of tau protein are associated with a variety of neurodegenerative diseases. Filaments made up of the 4R-tau isoform, which has four repeat regions (R1 to R4), are found in patients suffering from Alzheimer’s disease, while filaments made of the 3R-tau isoform, which contains only three repeat units (R1, R3, and R4), are found in patients with Pick’s disease (frontotemporal dementia). In this work, a predictive coarse-grained protein force field, the associative memory water-mediated structure and energy model (AWSEM), is used to study the energy landscapes of nucleation of the two different fibrils derived from patients with Pick’s and Alzheimer’s diseases. The landscapes for nucleating both fibril types contain amorphous oligomers leading to branched structures as well as prefibrillar oligomers. These two classes of oligomers differ in their structural details: The prefibrillar oligomers have more parallel in-register

β

-strands, which ultimately lead to amyloid fibrils, while the amorphous oligomers are characterized by a near random

β

-strand stacking, leading to a distinct amorphous phase. The landscape topography suggests that there must be significant structural reordering, or “backtracking,” to transit from the amorphous aggregation channel to the fibrillization channel. Statistical mechanical perturbation theory allows us to evaluate the effects of changing concentration on the aggregation free-energy landscapes and to predict the effects of phosphorylation, which is known to facilitate the aggregation of tau repeats.
Fusarium
wilt: a threat to banana cultivation and its management.
Authors: Thangavelu R. , Loganathan M. , Arthee R. , Prabakaran M. , Uma S.
Published: February 2020

Banana is affected by a wide number of diseases, of which,
Fusarium
wilt caused by
Fusarium oxysporum
f. sp.
cubense
(
Foc
) race 1 has played a major role in devastating Gros Michel banana plantations. Since 1960s, the pathogen
Foc
race 4 has threatened the survival and existence of the Cavendish group of bananas, which has necessitated detailed study on
Fusarium
wilt, the causal organism
Foc
, its biology, dispersal, pathogenicity, diversity and detection at a molecular level (especially in soils) and its management. The recently developed technique of transferring the gene encoding green fluorescent protein into
Foc
has assisted in visualizing and analysing the colonization and infection of banana plants by the pathogen. Studies on the pathogenicity secreted in xylem genes have helped in rapid detection of the pathogen
in planta
and techniques such as real-time fluorescence loop-mediated isothermal amplification assay have facilitated rapid and direct quantitative detection of
Foc
in soil. Several management practices, especially resistant varieties/transgenics and biological control methods are available for the effective management of this deadly disease. Strict quarantine procedures and reduction of
Foc
inoculum are the methods undertaken to limit the spread of the disease to other un-infected regions. This review summarizes the recent developments of
Fusarium
wilt in banana and its management.
Structural, optical and magnetic properties of Y3−0.02−xEr0.02Yb
x
Al5O12 (0 < x < 0.20) nanocrystals: effect of Yb content
Authors: Kamińska Izabela , Jankowski Dawid , Sikora Bożena , Kowalik Przemysław , Minikayev Roman , Wojciechowski Tomasz , Chojnacki Michał , Sobczak Kamil , Rybusiński Jarosław , Szczytko Jacek , Zajdel Karolina , Suchocki Andrzej , Paszkowicz Wojciech , Frontczak-Baniewicz Małgorzata , Fronc Krzysztof
Published: February 2020

The paramagnetic Y3−0.02−x
Er0.02Yb
x
Al5O12 (x = 0.02, 0.06, 0.10, 0.12, 0.18, 0.20) nanocrystals (NCs) were synthesized by the microwave-induced solution combustion method. The XRD, TEM and SEM techniques were applied to determine the NCs’ structures and sizes. The XRD patterns confirmed that the NCs have for the most part a regular structure of the Y3Al5O12 (YAG) phase. The changes of the distance between donor Yb3+ (sensitizer) and acceptor Er3+ (activator) were realized by changing the donor’s concentration with a constant amount of acceptor. Under 980 nm excitation, at room temperature, the NCs exhibited strong red emission near 660 and 675 nm, and green upconversion emission at 550 nm, corresponding to the intra 4f transitions of Er3+ (4F9/2,
2H11/2, 4S3/2) → Er3+ (4I15/2). The strongest emission was observed in a sample containing 18% Yb3+ ions. The red and green emission intensities are respectively about 5 and 12 times higher as compared to NCs doped with 2% of Yb3+. In order to prove that the main factor responsible for the increase of the upconversion luminescence efficiency is reduction of the distance between Yb3+ and Er3+, we examined, for the first time the influence of hydrostatic pressure on luminescence and luminescence decay time of the radiative transitions inside donor ion. The decrease of both luminescence intensity and luminescence decay times, with increasing hydrostatic pressure was observed. After applying hydrostatic pressure to samples with e.g. 2% and 6% Yb3+, the distance between the donor and acceptor decreases. However, for higher concentrations of the donor, this distance is smaller, and this leads to the effective energy transfer to Er3+ ions. With increasing pressure, the maximum intensity of near infrared emission is observed at 1029, 1038 and 1047 nm, what corresponds to 2F5/2 → 2F7/2 transition of Yb3+.
Electroactive actuator based on polyurethane nanofibers coated with polypyrrole through electrochemical polymerization: a competent method for developing artificial muscles
Authors: Ebadi Seyed Vahid , Fashandi Hossein , Semnani Dariush , Rezaei Behzad , Fakhrali Aref
Published: February 2020

In the present study, the electrochemical polymerization was carried out to coat the surface of electrospun polyurethane (PU) nanofibers with conductive electroactive polypyrrole (PPy) towards production of Faradaic bending actuators. For this purpose, the surface of electrospun nanofibers was first coated with a thin layer of gold using physical vapor deposition (PVD). PPy was then coated on the surface of prepared nanofibers using different consumed electric charges ranging from 0.5 to 5 C. The produced samples were characterized with respect to surface morphology, electrical properties, electrochemical properties and finally bending actuation performance of the produced actuators. The synthesis of PPy on the surface of nanofibers by the electrochemical polymerization process as well as preservation of the fibrous and porous structure of the samples was confirmed by SEM images. In the polymerization process, the amount of PPy coating on the surface of PU nanofibers increased dramatically with increasing the consumed electric charge. The results of the electrical properties of the produced nanofibrous layers showed that the surface resistivity of the produced PU/PPy nanofibrous layer was decreased from 719.5 to 51.3 Ω/sq for samples produced with the consumed charges of 0.5 and 5.0 C, respectively. Moreover, the electroactive properties of produced actuators were evaluated by cyclic voltammetry technique in a 0.1 M aqueous electrolyte solution of LiClO4 between potentials of −0.6 to 0.8 V. The results revealed that the electroactive properties of produced actuators were improved with increasing the amount of PPy coating. The evaluation of the bending actuation performance of the actuators showed that the angular displacement of the samples produced with consumed charges of 2, 3, 4 and 5 C in a potential cycle was 48°, 153°, 190° and 225°, respectively. These actuators have the potential to be applied in the fields of medicine, robotics and smart textiles.
Sample caching Markov chain Monte Carlo approach to boson sampling simulation
Authors: Liu Yong , Xiong Min , Wu Chunqing , Wang Dongyang , Liu Yingwen , Ding Jiangfang , Huang Anqi , Fu Xiang , Qiang Xiaogang , Xu Ping , Deng Mingtang , Yang Xuejun , Wu Junjie
Published: February 2020

Boson sampling is a promising candidate for quantum supremacy. It requires to sample from a complicated distribution, and is trusted to be intractable on classical computers. Among the various classical sampling methods, the Markov chain Monte Carlo method is an important approach to the simulation and validation of boson sampling. This method however suffers from the severe sample loss issue caused by the autocorrelation of the sample sequence. Addressing this, we propose the sample caching Markov chain Monte Carlo method that eliminates the correlations among the samples, and prevents the sample loss at the meantime, allowing more efficient simulation of boson sampling. Moreover, our method can be used as a general sampling framework that can benefit a wide range of sampling tasks, and is particularly suitable for applications where a large number of samples are taken.
Coriolis compensation via gravity in a matter-wave interferometer
Authors: Fein Yaakov Y , Kiałka Filip , Geyer Philipp , Gerlich Stefan , Arndt Markus
Published: February 2020

Matter-wave interferometry offers insights into fundamental physics and provides a precise tool for sensing. Improving the sensitivity of such experiments requires increasing the time particles spend in the interferometer, which can lead to dephasing in the presence of velocity-dependent phase shifts such as those produced by the Earth’s rotation. Here we present a technique to passively compensate for the Coriolis effect using gravity, without the need for any moving components. We demonstrate the technique with fullerenes in a long-baseline molecule interferometer by measuring the gravitational and Coriolis phase shifts and obtaining the maximum visibility one would expect in the absence of the Coriolis effect.
Progress in the conceptual design of the CFETR toroidal field coil with rectangular conductors
Authors: Liu Xiaogang , Wu Fan , Wang Zhaoliang , Li Guoqiang , Liu Xiaoju , Li Hang , Li Junjun , Ren Yong , Wu Yu , Gao Xiang
Published: February 2020

A comprehensive research facility project was approved in December 2018 with funding of 345 million EUR, to support the research and development of the China Fusion Engineering Test Reactor (CFETR). As part of this project, a full-size CFETR toroidal field (TF) coil will be designed, manufactured and tested by the Institute of Plasma Physics Chinese Academy of Sciences. Two options are being explored in parallel for the TF coil design, using either circle-in-square or rectangular cable-in-conduit conductors (CICCs). The rectangular CICC has been reported to have some merits for a DEMO TF coil, as reported in designs of the EU-DEMO and K-DEMO. First this paper presents the progress in the conceptual design of the CFETR TF coil with rectangular CICCs, according to the most recent reference single-null configuration and radial build of CFETR. Then, electromagnetic analyses are performed to give the magnetic field distributions, toroidal field ripple, in-plane and out-of-plane Lorentz loads. Finally, 3D global and 2D local mechanical analyses are conducted, and the detailed mechanical behavior of the TF coil is illustrated and discussed. Our analyses indicate that the present TF design is reasonable, considering the ITER criteria, and provides valuable insight into the mechanical behavior of the CFETR TF coil system.