bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forward elastic scattering: dynamical gluon mass and semihard interactions
Authors: Broilo M. , Fagundes D. A. , Luna E. G. S. , Menon M. J. 
Published: December 2019

AbstractThe role of low-xparton dynamics in dictating the high-energy behavior of forward scattering observables at LHC energies is investigated using a QCD-based model with even-under-crossing amplitude dominance at high-energies. We explore the effects of different sets of pre- and post-LHC fine-tuned parton distributions on the forward quantities$$\sigma _{tot}$$σtotand$$\rho $$ρ, fromppand$${\bar{p}}p$$p¯pscattering in the interval 10 GeV–13 TeV. We also investigate the role of the leading soft contribution, the low-energy cuttoff, and the energy dependence of the semihard form factor on these observables. We show that in all cases investigated the highly restrictive data on$$\rho $$ρparameter at$$\sqrt{s}=13$$s=13TeV indicate that a crossing-odd component may play a crucial role in forward elastic scattering at the highest energies, namely the Odderon contribution.
Investigation of distributed generation units placement and sizing based on voltage stability condition indicator (VSCI)
Authors: Raj Arvind , Aziz Nur Fadilah Ab , Yasin Zuhaila Mat , Salim Nur Ashida 
Published: December 2019

Voltage instability in power distribution systems can result in voltage collapse throughout the grid. Today, with the advanced of power generation technology from renewable sources, concerns of utility companies are much being focused on the stability of the grid when there is an integration of distributed generation (DG) in the system. This paper presents a study on DG units placement and sizing in a radial distribution network by using a pre-developed index called Voltage Stability Condition Index (VSCI). In this paper, VSCI is used to determine DG placement candidates, while the value of power losses is used to identify the best DG placement. The proposed method is tested on a standard 33-bus radial distribution network and compared with existing Ettehadi and Aman methods. The effectiveness of the method is presented in terms of reduction in power system losses, maximization of system loadability and voltage quality improvement. Results show that VSCI can be utilized as the voltage stability indicator for DG placement in radial distribution power system. The integration of DG is found to improve voltage stability by increasing the system loadability and reducing the power losses of the network.
A comparative study of cascade H-bridge multilevel voltage source inverter and parallel inductor multilevel current source inverter
Authors: Nik Ismail Nik Fasdi , Hashim Norazlan , Johari Dalina 
Published: December 2019

This paper presents the analysis study between multilevel inverters that are often classified into multilevel voltage source and multilevel current source inverters. For multilevel voltage source inverter (MVSI), the specific topology studied for this work is the Cascaded H-Bridge MVSI. Whereas, the multilevel current source inverter (MCSI) is based on Paralleled Inductor Configuration MCSI. For this study, the analysis between these converters are done with respect to the number of components, the advantages and disadvantages of each converters during performing inverter operation. In term of output voltage and current quality, the percentage of the Total Harmonic Distortion (THD) are measured and compared for both topologies. MATLAB/Simulink software has been used in this research to design and simulate in order to study the performances of both inverters.
Review of AC-DC power electronic converter topologies for power factor correction
Authors: Sasikala Rajagopal , Seyezhai R. 
Published: December 2019

<p>Increased harmonic content and low power factor in power systems caused by power converters have been of great concern. To overcome this, several converter topologies employing advanced semiconductor devices and control schemes have been proposed. The aim of this paper is to identify a low cost, small size, efficient and reliable ac to dc converter to meet the input performance index of uninterrupted power supply. In this paper, comparison between three converters namely AC-DC Cuk rectifier, Fly back converter &amp; Interleaved SEPIC converter have been carried out. For the above converters both bridged and bridgeless topologies have been analysed. The working of all the three types of converter has been illustrated with relevant waveforms followed by the simulation results. Comparison of the three converters have been done based on the parameters namely Displacement Factor, Supply Power Factor&amp; supply THD. The results are verified.</p>
Power compensation for vector-based current control of a modular multilevel converter (MMC) based STATCOM
Authors: Lawan Abdurrahman Umar , Babani S. , Abdulkarim A. , Shehu G. S. , Jibril M Y. , Madugu I. S. 
Published: December 2019

<p>This paper studies the suitability of a vector based current control which is mostly employed for its faster response in the reactive current applications of static compnesators (STATCOMs). The current control is mostly achieved using proportional-integral (PI) controllers because of the advantage of their good tracking and small variations. However, due to the dependency of PI controllers on the modular multilevel converter (MMC) system dynamics, performance variations arise during steady-state STATCOM non-ideal operations. This paper presents an improved MMC based STATCOM control with a d-q compensation algorithm added to the vector based current control. The algorithm is derived to tackle the effects of the dynamics of the MMC and the STATCOM ideal variations without the use of any additional controller. The control is achieved by providing a power compensation in the d,q-axis which injects currents at the input of the PI controllers in order to improve the steady-state performance of the STATCOM control.</p>
Comparative analysis of cascaded fuzzy-PI controllers based-MPPT and perturb and observe MPPT in a grid-connected PV system operating under different weather and loading conditions
Authors: Otmane Harici , Mouloudi Youssef , Mokhtar Bendjebbar 
Published: December 2019

<p>In this paper, a comparison is carried out between MPPT technique using a hybrid cascaded Fuzzy-PI Controller and Perturb and Observe (P&amp;O) MPPT technique. The two techniques are compared in a system which consists of a photovoltaic system connected to a grid via a two-level three-phase inverter. The P&amp;O and Fuzzy-PI techniques are examined under different weather conditions, namely, ramp change in irradiation level and ramp change in temperature levels. Disturbances represented by fluctuations in power demand from the utility grid is generated to assess the robustness of each of the two controllers. The Fuzzy-PI based MPPT, has proved its excellent tracking and robustness against abrupt perturbations. Simulations of the system performances using the two regulators are performed to validate the conceptual standings.</p>
Smooth transition from grid to standalone solar diesel mode hybrid generation system with a battery
Authors: Elsherbiny Aya M , Nada Adel S. , Ahmed Mohammed Kamal 
Published: December 2019

This paper described a self-supply smart microgrid which may be a low voltage or medium voltage distribution network. It considered an efficient energy system in which different renewable sources as photo-voltaic array, wind, or conventional as diesel generator, and storage called distributed generators which organized to chance the load power demand at any time with reliability. It can operate either on-grid or off-grid configuration, especially limited areas far from the utility grid needed another backup power. By using Matlab/Simulink, a solar PV system is modeled, simulated, and determined the characteristic of a particular photovoltaic cell panel under the influence of different values of ambient conditions. Taking into consideration MPPT algorithm which increases the solar energy efficiency by Incremental conductance technique to track MPP correctly with fast response. Power electronic DC/DC converter and DC/AC inverter are used with PWM technique. To compensate the power fluctuations of the system under different possible transient cases, a high performance control based on an improved virtual synchronous generator is added to confirm smooth variants in voltage, frequency and active power during transient conditions. The results show the PV/Diesel generator/battery/power/frequency and voltage performance at two different conditions.
Experimental investigation of artificial intelligence applied in MPPT techniques
Authors: Krachai Saidia Della , Stambouli A. Boudghene , Krachai M. Della , Bekhti M. 
Published: December 2019

Nano-satellites are key features for sharing the space data and scientific researches. They embed subsystems that are fed from solar panels and batteries. Power generated from these panels is subject to environmental conditions, most important of them are irradiance and temperature. Optimizing the usage of this power versus environmental variations is a primary task. Synchronous DC-DC buck converter is used to control the power transferred from PV panels to the subsystems while maintaining operation at maximal power. <br />In this paper, artificial intelligence techniques: neural networks and adaptive neural fuzzy inference systems (ANFIS) are used to accomplish the tracking task. Simulation and experimental results demonstrate their efficiency, robustness and tracking quality. <br /><br />
Significant implication of unified power quality conditioner in power quality problems mitigation
Authors: Hasan Kamrul , Othman Muhammad Murtadha , Rahman Nor Farahaida Abdul , Hannan M. A. , Musirin Ismail 
Published: December 2019

<p>This paper presents an analysis of a three-phase unified power quality conditioner (UPQC) in terms of design and performance. A back to back connection of a series compensator and a shunt compensator with a common DC-bus is utilized to build the UPQC model. The series compensator compensates the power quality problems such as grid voltage sags/swells for the grid side. During sag and swell condition, the compensated voltage is injected by the series compensator in phase with the point of common coupling (PCC) or out of phase with PCC. The load current harmonics is compensated by using the shunt compensator. The dynamic performance and the steady state of the designed model are analyzed by using MATLAB-Simulink under several disturbances such as PCC voltage harmonics, voltage sags/swells and load unbalancing using a nonlinear load. </p>
Performance Measures of Positive Output Superlift Luo Converter Using Multitudinous Controller
Authors: Ponnalagarsamy Sivagami , Jothi Swaroopan N. M. 
Published: December 2019

In order to meet the increase in energy demand globally it is necessary to harness renewable energy at its maximum potential for the purpose of electric power generation. For the achievement of high output voltage and efficiency DC-DC converters plays a vital role in low voltage PV array and fuel cells. LUO converters are gaining importance because of geometric progression output. . LUO converters find its application because of high transient performance of the system, high power transfer gain, efficiency and reduced ripple .Because of load and line disturbances the output voltage of DC-DC converter must be operated in closed loop mode. This paper interpolates multitudinous controller for positive output elementary super lift LUO converter (POESLL). The pursuance of the converter under manifold such as variation in input, load are developed and compared for current mode controller and SMC.
Simulation Models of Energy Cables in SPICE
Authors: Balaji Uma 
Published: December 2019

Accurate modeling of cables is important to study the behavior of high frequency disturbances in power converter systems. This paper reviews and compares two popular methodologies to model energy cables – an improved per unit length parameters based model and a Laplace SPICE element based model. The two models presented take into account the frequency dependence of the parameters of the cable. A ladder network is used for this purpose in the per unit length based model. The Laplace SPICE element model is generated from from a rational function approximation for the admittance parameters that are frequency dependant. The rational function approximation is obtained using a well known vector fitting algorithm. The time and frequency domain solutions of a two wire energy cable, obtained from the two models, agree well.
Biomarkers of Inflammation and Fibrosis in Kawasaki Disease Patients Years After Initial Presentation With Low Ejection Fraction
Authors: Hoshino Shinsuke , Shimizu Chisato , Jain Sonia , He Feng , Tremoulet Adriana H. , Burns Jane C. 
Published: December 2019

Background

Coronary artery aneurysms and myocarditis are well‐recognized complications of Kawasaki disease (
KD
) but no systematic evaluation of the consequences of myocarditis has been performed in the subset presenting with low ejection fraction (
EF
). We postulated that more severe myocardial inflammation as evidenced by low
EF
during the acute phase could lead to late myocardial fibrosis.

Methods and Results

We measured the carboxyterminal propeptide of procollagen type I (
PIPC
), soluble suppressor of tumorigenicity 2, galectin‐3 (Gal‐3), growth‐differentiation factor‐15, and calprotectin by
ELISA
in late convalescent blood samples from 16
KD
patients who had an
EF
≤55% on their initial echocardiogram. Results were compared with samples from sex‐ and age‐matched
KD
patients with initial
EF
>60%. In the univariate analysis, the median Gal‐3 and
PIPC
levels in the low
EF
group were significantly higher than those in the normal
EF
group (Gal‐3: low
EF
6.216 versus normal
EF
4.976 mg/dL
P
=0.038,
PIPC
: low
EF
427.4 versus normal
EF
265.2 mg/dL,
P
=0.01). In a multivariable analysis, there were significant differences for Gal‐3 and
PIPC
levels between the low and normal
EF
groups, adjusting for age, sex, and worst z score.

Conclusions

Convalescent
KD
patients with a history of low
EF
during the acute illness had significantly elevated levels of Gal‐3 and
PIPC
when compared with matched‐control
KD
patients with normal
EF
. These findings raise concern for myocardial fibrosis as a potential late sequela of the more severe myocarditis experienced by a subset of
KD
patients during the acute phase.
Changing Probabilities of Days with Snow and Rain in the Atlantic Sector of the Arctic under the Current Warming Trend
Authors: Łupikasza E. B. , Cielecka-Nowak K. 
Published: December 2019

AbstractTrends in the probabilities of days with liquid, solid, and mixed precipitation are discussed on annual and intra-annual scales along with their relationship to air temperature in the Atlantic sector of the Arctic. Data on weather phenomena were used to identify precipitation phases. The data cover various periods but all series extend to 2017. Trends in the annual air temperature and probability of precipitation phases for various long-term periods are discussed and differences in the mean air temperature and probability of precipitation phases between 1979–97 (insignificant warming) and 1999–2017 (significant warming) on an intra-annual scale. In the studied region, the precipitation phases were sensitive to warming and atmospheric circulation to various degrees, depending on the phase, mean climate, month, and local conditions. The probability of days with rainfall increased (by +1% to +3% per decade), whereas the probability of days with snowfall decreased (by −1.5% to −2.4% per decade). The increasing trends in the probability of rainy days at all stations and decreasing trends in the probability of snowy days in the southern part of the region were warming induced. The most significant and widespread trends in snowy and rainy days were found in September. The probability of days with mixed precipitation exhibited no trends due to an inverse reaction to warming in the warmer and colder parts of the year. Temporal variability in the probability of precipitation phases was significantly linked to three teleconnection patterns playing a role in various parts of the year.
Investigation of Tipping-Bucket Rain Gauges Using Digital Photographic Technology
Authors: Liao Minhan , Liu Jiufu , Liao Aimin , Cai Zhao , Huang Yixin , Zhuo Peng , Li Xuegang 
Published: December 2019

AbstractWhen studying the tipping-bucket rain gauge (TBR), it is rather difficult to make an objective and sophisticated measurement of the duration of bucket rotation. From the perspective of digital photographic technology, however, the problem can be easily solved. The primary interest of this research has been to use digital photographic technology to study the TBR under laboratory conditions. In this study, the interframe difference algorithm and a camera recording device were used. Based on three types of JDZ TBRs, the time variation characteristics of bucket rotation were obtained. The time from the beginning of a tip to the time that the bucket is horizontal T1 and the time for a complete tip T2 were analyzed in detail. The results showed that T1 and T2 were functions of rainfall intensity, and T1 and T2 decrease as the rain intensity increases significantly (P < 0.001). Moreover, excellent evidence shows that the averages of T1 and T2 were positively correlated with bucket mass. It took more time for the bucket to tip as the mass of the bucket increased. Furthermore, the error of each TBR was calculated by the new proposed error calculation formula, and the new method was compared with the traditional method. The results from the two methods were very close, which demonstrates the correctness and feasibility of the new formula. However, the traditional calibration cannot acquire the variation characteristics of the tipping time, but the proposed approach can achieve this.
Sea Level Anomaly Forecasts on a Coastal Waveguide
Authors: Taylor Andy , Brassington Gary B. 
Published: December 2019

Abstract
An approach to reduce forecast data to coastal waveguide coordinates is described and demonstrated, informed by the literature on coastally trapped waves (CTWs). All discussion is limited to the Australian mainland but the approach is generally relevant to regions where CTWs influence sea level, including the Americas and Africa. The approach does not produce new forecasts, but aims to focus forecaster attention on aspects of sea level forecasts prominent on the long Australian coast. The approach also explicitly addresses spatial issues associated with measuring coastal paths. Coastal paths are scale dependent and forecast models discretize the coastal boundary differently. A well-defined coastal path is required for the quantitative application of CTW concepts such as propagation distance and offshore direction. The relevance of coastally trapped signals and remote forcing is documented in the oceanographic literature, but is effectively unknown to the general public and rarely mentioned in press reports of sea level events such as nuisance flooding. Routine presentation of forecast guidance in waveguide coordinates could contribute to the transfer of oceanographic research understanding into forecast narratives. In addition, the approach can facilitate quantitative forecast evaluations that target CTW properties. Two ocean forecast systems are contrasted in this framework for the Australian mainland. One year of daily forecasts are compared, with indications that model baroclinicity is of practical relevance.
Effects of olive oil on physical and mechanical properties of ceramic waste-based geopolymer foam
Authors: Lertcumfu Narumon , Kaewapai Kannikar , Jaita Pharatree , Tunkasiri Tawee , Sirisoonthorn Somnuk , Rujijanagul Gobwute 
Published: December 2019

The present study concentrated on porous geopolymer composites (between calcined clay and metakaolin) using hydrogen peroxide as a pore generation agent. To reduce as well as recycle the waste from a factory, calcined clay waste was used as starting material. The geopolymer was synthesized via a geopolymerization method by a reaction with an alkaline solution, using the ceramic waste and metakaolin as raw materials. Different amount of olive oil (0–15 wt%) were added to the samples. The olive oil affected the pore formation of the geopolymers. The effects of olive oil, a surfactant, on the properties of the geopolymer composites were investigated. Apparent density and compressive strength of the samples tended to decrease with the additive, while water absorption and total porosity had the opposite effect. However, a variation in the apparent density and water absorption values was observed, due to the formation of closed pores in the samples. The trend of compressive strength value was related with total porosity. A model for pore formation was proposed in this work. The results suggest that this material can be used as a geopolymer foam.
Understanding International Space Law and the Liability Mechanism for Commercial Outer Space Activities—Unravelling the Sources
Authors: Gupta Biswanath , Raju KD  
Published: December 2019

The status and liability of non-governmental entities for commercial use of outer space activities on behalf of space launching states are not very clear under the existing space law regimes. Non-governmental entities are those who carry private space activities such as commercial launching, supplying different equipment or parts to space agencies and manufacturing spacecraft and satellite. The possible litigation relating to the commercial activities are mainly the financial consequence of damage caused and also the technical complications that private entities face in case of supply of defaulted parts to the space agencies. According to Article VI of the Outer Space Treaty 1967 and Articles II and III of Liability Convention 1972, launching country is liable for any activities in outer space. Even in the case of non-governmental activities, the launching state is liable. Therefore, in the event of any commercial activity from any sovereign states, the state is liable for any accidents and consequential damages. This article focusses on specific issues such as liability for commercial outer space activities of nongovernmental entities in the existing international space law regimes. It explores the applicable principle of space law and international law in outer space activities. The work also focusses on the impact on space liability regime as well as on the legal efficiency of the links between private entities and state liability. This exercise is important in the background of the increasing number of private spacecrafts scheduled for launching in the future.