bluuebunny/crossref_metadata_2025 huggingface dataset:
Educational Organizational and Leadership Analysis in Elementary School
Authors: Tamam Badrud , Sunaengsih Cucun , Safitri Noneng , Hotimah Rima Nurul , Mumtazah Wakhidah , Rahmadhani Gita
Published: June 2020

The aim of this research was to determine educational organization and leadership in elementary school in West Java, Indonesia by principals as the research informants. The method used was qualitative research method with analysis descriptive approach. This research qualitatively describes and analyzes principal leadership style and educational organization in improving teacher performance in elementary schools in West Java, Indonesia. The data collection technique was using interview and documentation study techniques. Results of the research show that 1. There is not too complex organizational structure seen from organizational horizontal differential aspect as well as the organizational structure is not standard; 2. Principal leadership greatly influences on teacher performance. From the findings, it is necessary for a visionary leader with ability to support the organization to be more dynamic one and influence positively on improvement of teacher performance.
Predicting species richness and abundance of tropical post-larval fish using machine learning
Authors: Jaonalison H , Durand JD , Mahafina J , Demarcq H , Teichert N , Ponton D
Published: June 2020

Post-larval prediction is important, as post-larval supply allows us to understand juvenile fish populations. No previous studies have predicted post-larval fish species richness and abundance combining molecular tools, machine learning, and past-days remotely sensed oceanic conditions (RSOCs) obtained in the days just prior to sampling at different scales. Previous studies aimed at modeling species richness and abundance of marine fishes have mainly used environmental variables recorded locally during sampling and have merely focused on juvenile and adult fishes due to the difficulty of obtaining accurate species richness estimates for post-larvae. The present work predicted post-larval species richness (identified using DNA barcoding) and abundance at 2 coastal sites in SW Madagascar using random forest (RF) models. RFs were fitted using combinations of local variables and RSOCs at a small-scale (8 d prior to fish sampling in a 50 × 120 km2 area), meso-scale (16 d prior; 100 × 200 km2), and large-scale (24 d prior; 200 × 300 km2). RF models combining local and small-scale RSOC variables predicted species richness and abundance best, with accuracy around 70 and 60%, respectively. We observed a small variation of RF model performance in predicting species richness and abundance among all sites, highlighting the consistency of the predictive RF model. Moreover, partial dependence plots showed that high species richness and abundance were predicted for sea surface temperatures <27.0°C and chlorophyll a concentrations <0.22 mg m-3. With respect to temporal changes, these thresholds were solely observed from November to December. Our results suggest that, in SW Madagascar, species richness and abundance of post-larval fish may only be predicted prior to the ecological impacts of tropical storms on larval settlement success.
Fatty acids and stable isotopes (δ13C, δ15N) in southern right whale Eubalaena australis calves in relation to age and mortality at Península Valdés, Argentina
Authors: Marón CF , Budge SM , Ward RE , Valenzuela LO , Di Martino M , Ricciardi M , Sironi M , Uhart M , Seger J , Rowntree VJ
Published: June 2020

Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whaleEubalaena australispopulation that calves off Península Valdés, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous studies found that the population’s reproductive success is influenced by prey availability. Mothers unable to build sufficient fat reserves or feeding on prey with different nutritional value may fail to meet the demands of lactation. Milk is the only source of nutrients and energy for calves at Valdés, so their fatty acids (FAs) and stable isotopes should reflect their mother’s diet and feeding-ground locations. Here, we compared FA profiles and C and N stable isotopes of dead calves with those of living calves to evaluate the potential impact of maternal nutrition on calf survival. We found no differences in the FA composition of blubber in dead and living calves, indicating similar maternal diets. Likewise, the isotopic values of living and dead calves imply that their mothers had similar foraging ranges. However, FA composition was greatly affected by calf length, indicating effects of calf age and duration of nursing. These findings suggest that mothers of dead calves did not feed on different diets or feeding grounds compared to mothers of living calves. Future research should further assess the overall health and body condition of the Valdés southern right whale calves.
Skapula Örneklerinin Morfometrik Değerlendirmesi ve Anatomik Varyasyonları
Authors: AYDEMİR Ahmet Nadir , YÜCENS Mehmet , ONUR Şule
Published: June 2020

İskelet sisteminin en büyük yassı kemiklerinden olan skapula göğüs duvarının arkasında yer almaktadır. Skapulanın kendine has morfometrik özellikleri ve anatomik varyasyonları bulunmaktadır. Glenoid yapısı ve akromiyon tipi varyasyon gösteren yapılarındandır. Bu çalışmada skapulanın morfometrik özellikleri ile birlikte anatomik varyasyonlarının değişkenliği değerlendirilmiş, literatürde yapılan çalışmalar ile karşılaştırılıp sonuçları ortaya konmaya çalışılmıştır. Pamukkale Üniversitesi Tıp Fakültesi Anatomi Anabilim Dalı’nda mevcut olan 16 sağ ve 24 sol olmak üzere toplam 40 adet skapula, milimetrik hassasiyet gösteren dijital kumpas ile ölçülmüştür. Bunun yanında tüm skapulaların akromiyon ve glenoid yapıları değerlendirilip tiplendirilmesi yapılmıştır. Kırk skapulanın ortalama yüksekliği 14,7 mm, genişlik ortalaması 10,5 mm olarak bulunmuştur. Spina scapulae’nin uzunluk ortalaması 13,3 mm ölçülmüştür. Ortalama akromiyon uzunluğu ve genişliği sırasıyla 4,7 mm ve 2,3 mm olarak saptanmıştır. Akromiyon tiplendirilmesinde 10 akromiyonun düz, 15’inin konkav, 15’inin ise çengelli olduğu görülmüştür. Akromiyonlar şekillerine göre ayrıldığında 14’ü kobra şekilli, 13’ü ara, 13’ü de kare şekilli olduğu izlenmiştir. Glenoidlerin 18’i virgül şekilli, 13’ü oval, 9’u ise armut şekilli olarak bulunmuştur. Anatomi laboratuvarında bulunan kırk skapulanın uzunluk parametrelerini ve tiplerini ortaya koymaya çalıştığımız bu çalışmada ulaşılan sonuçları literatürdeki diğer araştırmalarla karşılaştırdığımızda biyolojik çeşitlilikler görülmüştür. Bu tip antropometrik çalışmaların daha geniş serilerde, çok merkezli ve karşılaştırmalı olarak yapılmasına ihtiyaç duyulmaktadır.
Geographies of Gender: Social Politics of the Partner Dance Venue
Authors: Kaminsky David
Published: June 2020

The typical partner dance venue will have a standardised layout conducive to the space's function as a marketplace in which attendees can display their own bodies as commodities. Dancers in the venue will have invested time and money in training, clothing, and grooming to demonstrate the value of their bodies according to the dance's typically heteronormative standards. The reward for successful marketing is physical access to other similarly well-marketed bodies. The social enforcement of this system occurs primarily at the moment between songs, when large numbers of attendees engage in a simultaneous process of partner selection.
Clinical experience with scleral lenses for correction
of induced ametropia
Authors: Stepanova Ludmila , Alekseeva Maria
Published: June 2020

We described clinical cases of scleral lenses fitting in patients with induced ametropia and have shown the efficiency of this optical correction. High functional results and comfortable use make scleral lenses the main optical correction method for patients with irregular corneas after refractive surgery procedures.
Turnover of Urea in a Soil from the North China Plain as Affected by the Urease Inhibitor NBPT and Wheat Straw
Authors: Hartmann Tobias Edward , Guzman-Bustamante Ivan , Ruser Reiner , Müller Torsten
Published: June 2020

In the North China Plain (NCP), urea is applied to predominantly high-pH soils and high gaseous losses of N are observed in the forms of ammonia (NH3) and nitrous oxide (N2O). The production of N2O and N2 is further stimulated by the addition of fresh organic materials. The urease inhibitor (UI) N-(n-butyl) thiophosphoric triamide (NBPT) restricts the loss of N by reducing the rate of urea hydrolysis and limiting the substrates for NH3 and N2O emission. We investigated the turnover of N—as well as the emissions of NH3, N2O and CO2—as affected by the addition of wheat straw and urea +NBPT in an incubation experiment using soil from a farmer’s field, typical for the NCP. Added wheat straw prolonged the persistence of NH4+ after the application of both urea and urea +NBPT, while reducing the formation of nitrate. Wheat straw may therefore either act as a stimulant of hydrolysis or as an inhibitor of nitrification. Urea increased soil respiration and the emission of N2O, possibly acting as a primer for microbial activity as described in earlier studies. In combination with the application of organic C sources, this effect of urea may be a main driver of gaseous N loss.
The AMP-Activated Protein Kinase Plays a Role in Antioxidant Defense and Regulation of Vascular Inflammation
Authors: Jansen Thomas , Kvandová Miroslava , Daiber Andreas , Stamm Paul , Frenis Katie , Schulz Eberhard , Münzel Thomas , Kröller-Schön Swenja
Published: June 2020

Cardiovascular diseases represent the leading cause of global deaths and life years spent with a severe disability. Endothelial dysfunction and vascular oxidative stress are early precursors of atherosclerotic processes in the vascular wall, all of which are hallmarks in the development of cardiovascular diseases and predictors of future cardiovascular events. There is growing evidence that inflammatory processes represent a major trigger for endothelial dysfunction, vascular oxidative stress and atherosclerosis and clinical data identified inflammation as a cardiovascular risk factor on its own. AMP-activated protein kinase (AMPK) is a central enzyme of cellular energy balance and metabolism that has been shown to confer cardio-protection and antioxidant defense which thereby contributes to vascular health. Interestingly, AMPK is also redox-regulated itself. We have previously shown that AMPK largely contributes to a healthy endothelium, confers potent antioxidant effects and prevents arterial hypertension. Recently, we provided deep mechanistic insights into the role of AMPK in cardiovascular protection and redox homeostasis by studies on arterial hypertension in endothelial and myelomonocytic cell-specific AMPK knockout (Cadh5CrexAMPKfl/fl and LysMCrexAMPKfl/fl) mice. Using these cell-specific knockout mice, we revealed the potent anti-inflammatory properties of AMPK representing the molecular basis of the antihypertensive effects of AMPK. Here, we discuss our own findings in the context of literature data with respect to the anti-inflammatory and antioxidant effects of AMPK in the specific setting of arterial hypertension as well as cardiovascular diseases in general.
Simultaneous Enhancement of Electrical and Optical Properties of Transparent Conducting RuO2 Nanosheet films by Facile Ultraviolet-Ozone Irradiation
Authors: Roh Jong Wook , Shin Weon Ho , Kim Hyun-Sik , Kim Se Yun , Kim Sang-il
Published: June 2020

The enhancement of electrical and optical properties in transparent conducting electrodes has attracted significant interest for their application in flexible electronic devices. Herein, a method for the fabrication of transparent conducting films is proposed. In this approach, RuO2 nanosheets are synthesized by a simple chemical exfoliation method and deposited as conducting films by repeated Langmuir–Blodgett coating. For enhancing the electrical and optical properties of the films, ultraviolet-ozone irradiation is applied between the repeated coatings for the removal of residual organic materials from the chemically exfoliated nanosheets. We observe that by applying ultraviolet-ozone irradiation for 30 min, the sheet resistance of the films decreases by 10% and the optical transmittance is simultaneously enhanced. Facile ultraviolet-ozone irradiation is shown to be an effective and industrially friendly method for enhancing the electrical and optical properties of oxide nanosheets for their application as transparent conduction electrodes.
Shock Loading of Closed Cell Aluminum Foams in the Presence of an Air Cavity
Authors: Thorat Mahesh , Sahu Shiba , Menezes Viren , Gokhale Amol , Hosano Hamid
Published: June 2020

It is important to protect assets located within cavities vulnerable to incident shock waves generated by explosions. The aim of the present work is to explore if closed cell aluminum foams can mediate and attenuate incident shocks experienced by cavities. A small cavity of 9 mm diameter and 2 mm length was created within the steel end-wall of a shock tube and exposed to shocks, directly or after isolating by aluminum foam liners. Shock waves with incident pressure of 9–10 bar travelling at a velocity of 1000–1050 m/s were generated in the shock tube. Compared to the no-foam condition, the pressure induced in the cavity was either equal or lower, depending on whether the foam density was low (0.28 g/cc) or high (0.31 to 0.49 g/cc), respectively. Moreover, the rate of pressure rise, which was very high without and with the low density foam barrier, reduced substantially with increasing foam density. Foams deformed plastically under shock loading, with the extent of deformation decreasing with increasing foam density. Some interesting responses such as perforation of cell walls in the front side and densification in the far side of the foam were observed by a combination of scanning electron microscopy and X-ray microscopy. The present work conclusively shows that shocks in cavities within rigid walls can be attenuated by using foam liners of sufficiently high densities, which resist densification and extrusion into the cavities. Even such relatively high-density foams would be much lighter than fully dense materials capable of protecting cavities from shocks.
Municipal Solid Waste Incineration Bottom Ash as Sole Precursor in the Alkali-Activated Binder Formulation
Authors: Maldonado-Alameda Àlex , Giro-Paloma Jessica , Alfocea-Roig Anna , Formosa Joan , Chimenos Josep Maria
Published: June 2020

The concern about the large amount of weathered bottom ash (WBA) produced in waste-to-energy plants (WtE) has caused an increased search for alternatives to reduce their environmental impact. The present study aims to provide an added value through the WBA valorization from municipal solid waste incineration (MSWI) for its use as a sole precursor for developing alkali-activated binders (AABs). Alkali-activated weathered bottom ash binders (AA-WBA) were formulated with a liquid-to-solid ratio of 1.0 and using sodium silicate (80 wt.%) and NaOH (20 wt.%) at different concentrations (2, 4, 6, and 8M) as alkali-activator solutions. AA-WBA were cured at room temperature to extend their applicability. The effect of the alkali-activator solution molarity on the final properties of the AA-WBA was evaluated. The physicochemical characterization by XRD, FTIR, and SEM evidenced the presence of the typical phases (calcium silicate hydrate and gehlenite) of C-(A)-S-H gel. Leaching concentrations of As, Cu, and Mo exceed the acceptance in landfills for inert waste, while the leaching concentration of Sb exceeds the one for non-hazardous waste. The structure of the binders depends on the alkalinity of the activator, obtaining better results using NaOH 6M in terms of microstructure and compressive strength (6.7 MPa). The present study revealed that AA-WBA for non-structural purposes can be obtained. The AA-WBA formulation contributes to the WBA valorization and development of low-carbon cements; therefore, it is an encouraged alternative to ordinary Portland cement (OPC). Considering the amounts and costs of the WBA, sodium silicate, NaOH, and water, the total cost of the developed formulations is comprised in a range between 137.6 and 153.9 €/Tn.
Evaluation and Monitoring of Slope Stability in Cold Region: Case Study of Man-Made Slope at Øysand, Norway
Authors: Shin Yunsup , Choi Jung Chan , Quinteros Santiago , Svendsen Ida , L'Heureux Jean-Sebastien , Seong Joohyun
Published: June 2020

Recently, the road and railways infrastructure developments in Norway have led to renewed interests on the geotechnical challenges associated with slope stability under freezing-thawing cycles. Despite the amount of research available on the topic, there are few comprehensive studies involving laboratory testing, numerical analysis, and field monitoring of a slope during a freezing–thawing. In this case study, a critical slope was identified in a cold region based on field and laboratory tests, and a series of numerical simulations were carried out to evaluate the governing factor of slope stability using finite element methods. A remote monitoring system was installed on a real scale man-made slope to observe its behavior against the governing factors of slope stability. As a result, it was found that slope stability at the critical slope was significantly impacted by the freezing–thawing action, which was confirmed by the initial field observations from 2019 to 2020. Later, continuous monitoring data could be used to update soil parameters and to implement an early warning system for the high risky slope areas effected by freezing–thawing action in many cold regions.
CTELS: A Cell-Free System for the Analysis of Translation Termination Rate
Authors: Lashkevich Kseniya A. , Shlyk Valeriya I. , Kushchenko Artem S. , Gladyshev Vadim N. , Alkalaeva Elena Z. , Dmitriev Sergey E.
Published: June 2020

Translation termination is the final step in protein biosynthesis when the synthesized polypeptide is released from the ribosome. Understanding this complex process is important for treatment of many human disorders caused by nonsense mutations in important genes. Here, we present a new method for the analysis of translation termination rate in cell-free systems, CTELS (for C-terminally extended luciferase-based system). This approach was based on a continuously measured luciferase activity during in vitro translation reaction of two reporter mRNA, one of which encodes a C-terminally extended luciferase. This extension occupies a ribosomal polypeptide tunnel and lets the completely synthesized enzyme be active before translation termination occurs, i.e., when it is still on the ribosome. In contrast, luciferase molecule without the extension emits light only after its release. Comparing the translation dynamics of these two reporters allows visualization of a delay corresponding to the translation termination event. We demonstrated applicability of this approach for investigating the effects of cis- and trans-acting components, including small molecule inhibitors and read-through inducing sequences, on the translation termination rate. With CTELS, we systematically assessed negative effects of decreased 3′ UTR length, specifically on termination. We also showed that blasticidin S implements its inhibitory effect on eukaryotic translation system, mostly by affecting elongation, and that an excess of eRF1 termination factor (both the wild-type and a non-catalytic AGQ mutant) can interfere with elongation. Analysis of read-through mechanics with CTELS revealed a transient stalling event at a “leaky” stop codon context, which likely defines the basis of nonsense suppression.
The Potassium-Induced Decomposition Pathway of HCOOH on Rh(111)
Authors: Kovács Imre , Kiss János , Kónya Zoltán
Published: June 2020

Formic acid (FA) can be considered both a CO and a H2 carrier via selective dehydration and dehydrogenation pathways, respectively. The two processes can be influenced by the modification of the active components of the catalysts used. In the present study the adsorption of FA and the decomposition of the formed formate intermediate were investigated on potassium promoted Rh(111) surfaces. The preadsorbed potassium markedly increased the uptake of FA at 300 K, and influenced the decomposition of formate depending on the potassium coverage. The work function (Δϕ) is increased by the adsorption of FA on K/Rh(111) at 300 K suggesting a large negative charge on the chemisorbed molecule, which could be probably due to the enhanced back-donation of electrons from the K-promoted Rh into an empty π orbital of HCOOH. The binding energy of the formate species is therefore increased resulting in a greater concentration of irreversibly adsorbed formate species. Decomposition of the formate species led to the formation of H2, CO2, H2O, and CO, which desorbed at significantly higher temperatures from the K-promoted surface than from the K-free one as it was proven by thermal desorption studies. Transformation of surface formate to carbonate (evidenced by UPS) and its decomposition and desorption is responsible for the high temperature CO and CO2 formation.
Synthesis of Naphthoxazinones in a One-Pot Two-Step Manner by the Application of Propylphosphonic Anhydride (T3P®)
Authors: Varga Valentina , Ábrányi-Balogh Péter , Milen Mátyás
Published: June 2020

A sequential one-pot two-step protocol has been elaborated for the synthesis of naphthoxazinones from 2-naphthol, methyl carbamate, and aromatic aldehydes. First, a three-component reaction was optimized with the dehydrating additive propylphosphonic anhydride (T3P®), resulting in 1-carbamatoalkyl 2-naphthols in good to excellent yields. Following the successful multicomponent approach, intramolecular acylation was performed at high temperature, again with the contribution of T3P®, resulting in naphthoxazinone derivatives in moderate yields. These two steps were optimized together in one-pot as well, and the sequential rise in the requisite temperature eventuated the optimal procedure for the multistep cascade.
Managing the Performance of Asset Acquisition and Operation with Decision Support Tools
Authors: Lattanzio Susan , Newnes Linda , McManus Marcelle , Dunkley Derrick
Published: June 2020

Decision support tools (DSTs) are increasingly being used to assist with asset acquisition and management decisions. Whether these tools are “fit for purpose” will have both economic and non-economic implications. Despite this, the on-going governance of DST performance receives only limited attention within both the academic and industry literature. This work addresses that research gap. Within this paper a conceptual process for managing the operational performance of decision support tools is presented. The novelty of the approach is that it aligns with the ISO 5500x:2014 Asset Management Standard, therefore introducing consistency in the governance of DSTs with physical engineered assets. A case study of the UK’s National Grid Electricity Transmission (NGET) is used to inform the approach design. The evaluation demonstrates it to be both logical and useable within the context of NGET and they have expressed an intention to implement the approach within their business. A key finding of the research was that DSTs transcend functions and organisations. This is significant and can lead to a situation whereby performance and criticality are interpreted and measured differently. The introduction of a common approach for managing DST performance works towards improving consistency and creating a shared understanding.
Electroreforming of Glucose and Xylose in Alkaline Medium at Carbon Supported Alloyed Pd3Au7 Nanocatalysts: Effect of Aldose Concentration and Electrolysis Cell Voltage
Authors: Rafaïdeen Thibault , Neha Neha , Kouamé Bitty Roméo Serge , Baranton Stève , Coutanceau Christophe
Published: June 2020

The effects of cell voltage and of concentration of sugars (glucose and xylose) on the performances of their electro-reforming have been evaluated at a Pd3Au7/C anode in 0.10 mol L−1 NaOH solution. The catalyst synthesized by a wet chemistry route is first comprehensively characterized by physicochemical and electrochemical techniques. The supported catalyst consists in alloyed Pd3Au7 nanoparticles of circa 6 nm mean diameter deposited on a Vulcan XC72 carbon support, with a metal loading close to 40 wt%. Six-hour chronoamperometry measurements are performed at 293 K in a 25 cm2 electrolysis cell for the electro-conversion of 0.10 mol L−1 and 0.50 mol L−1 glucose and xylose at cell voltages of +0.4 V, +0.6 V and +0.8 V. Reaction products are analyzed every hour by high performance liquid chromatography. The main products are gluconate and xylonate for glucose and xylose electro-reforming, respectively, but the faradaic yield, the selectivity and the formation rate of gluconate/xylonate decrease with the increase of aldose concentration, whereas lower faradaic yields and higher formation rates of gluconate/xylonate are observed at +0.8 V than at +0.4 V (higher chemical yields).
Delivery Systems for Hydroxytyrosol Supplementation: State of the Art
Authors: De Leonardis Antonella , Macciola Vincenzo , Iacovino Silvio
Published: June 2020

This review aims to highlight the benefits and limitations of the main colloid-based available delivery systems for hydroxytyrosol. Hydroxytyrosol is a phenolic compound with clear biological activities for human wellness. Olive fruits, leaves and extra-virgin oil are the main food sources of hydroxytyrosol. Moreover, olive oil mill wastewaters are considered a potential source to obtain hydroxytyrosol to use in the food industry. However, recovered hydroxytyrosol needs adequate formulations and delivery systems to increase its chemical stability and bioavailability. Therefore, the application of hydroxytyrosol delivery systems in food sector is still a fascinating challenge. Principal delivery systems are based on the use of colloids, polymers able to perform gelling, thickening and stabilizing functions in various industrial sectors, including food manufacturing. Here, we review the recipes for the available hydroxytyrosol systems and their relative production methods, as well as aspects relative to system characteristics and hydroxytyrosol effectiveness.
Quadruplicate Synchronous Adenocarcinoma of the Colon with Distant Metastases—Long-Term Molecular Follow-Up by KRAS and TP53 Mutational Profiling
Authors: Bádon Emese Sarolta , Mokánszki Attila , Mónus Anikó , András Csilla , Damjanovich László , Méhes Gábor
Published: June 2020

Anatomically independent tumor foci represent biologically distinct neoplasias, potentially featured by different progressivity and treatment responsiveness. To demonstrate the biological complexity, a metastatic colon adenocarcinoma patient originally presenting with four independent primary tumors of the right colon half and altogether eight distant metastases was followed by molecular testing. Next-generation sequencing results highlighted the mutational profile of the individual primaries and the dynamics of the different gene variants observed during follow-up. The four primary colon tumors presented with four different KRAS genotypes, one of them with a wild-type and three with pathogenic variants, without overlap. These were the following: c.35G > A; p.Gly12Asp with 40.6% variant allele frequency (VAF); c.34G > T; p.Gly12Cys with 16.2% VAF and c.35G > T; p.Gly12Val with 15.1% VAF. In metastatic tumors, with one exception where no mutation was detected, only the KRAS c.34G > T; p.Gly12Cys mutation could be detected. TP53 gene variants were variable in the primary tumors, with a single dominant variant evolving in the follow-up metastases (c.820G > T; p.Val274Phe). Genetic profiling of individually developing synchronous malignancies uncovers the clonal relations of metastatic tumors. NGS gene panels provide a solution to follow the dynamics of key oncogene variants during the course of the disease and greatly contribute to therapy optimization.
Maximum Varma Entropy Distribution with Conditional Value at Risk Constraints
Authors: Liu Chang , Chang Chuo , Chang Zhe
Published: June 2020

It is well known that Markowitz’s mean-variance model is the pioneer portfolio selection model. The mean-variance model assumes that the probability density distribution of returns is normal. However, empirical observations on financial markets show that the tails of the distribution decay slower than the log-normal distribution. The distribution shows a power law at tail. The variance of a portfolio may also be a random variable. In recent years, the maximum entropy method has been widely used to investigate the distribution of return of portfolios. However, the mean and variance constraints were still used to obtain Lagrangian multipliers. In this paper, we use Conditional Value at Risk constraints instead of the variance constraint to maximize the entropy of portfolios. Value at Risk is a financial metric that estimates the risk of an investment. Value at Risk measures the level of financial risk within a portfolio. The metric is most commonly used by investment bank to determine the extent and occurrence ratio of potential losses in portfolios. Value at Risk is a single number that indicates the extent of risk in a given portfolio. This makes the risk management relatively simple. The Value at Risk is widely used in investment bank and commercial bank. It has already become an accepted standard in buying and selling assets. We show that the maximum entropy distribution with Conditional Value at Risk constraints is a power law. Algebraic relations between the Lagrangian multipliers and Value at Risk constraints are presented explicitly. The Lagrangian multipliers can be fixed exactly by the Conditional Value at Risk constraints.
Special Characteristics and Synchronizations of Multi Hybrid-Order Chaotic Systems
Authors: Liu Jiaxun , Wang Zuoxun , Zhang Fangfang , Yin Yankai , Ma Fengying
Published: June 2020

Based on advantages of integer and fractional chaotic systems, hybrid chaotic systems and their definitions and some fundamental concepts are proposed, such as hybrid degree (HD), the lowest order (LO) and the total dimension order (TDO). The preliminary properties of hybrid Lorenz systems and hybrid forms of some classic chaotic systems are studied. Then, the relations between HD, LO and TDO with different parameters is investigated in chaotic systems. To be specific, HD is associated with fractional order. It is a directional method to search LO and TDO in chaotic systems. Finally, based on the incommensurate fractional stability theory, we accomplish combination synchronization for three different hybrid order chaotic systems. The simulation results verify the effectiveness of the synchronization controller.
Power-Law Distributions of Dynamic Cascade Failures in Power-Grid Models
Authors: Ódor Géza , Hartmann Bálint
Published: June 2020

Power-law distributed cascade failures are well known in power-grid systems. Understanding this phenomena has been done by various DC threshold models, self-tuned at their critical point. Here, we attempt to describe it using an AC threshold model, with a second-order Kuramoto type equation of motion of the power-flow. We have focused on the exploration of network heterogeneity effects, starting from homogeneous two-dimensional (2D) square lattices to the US power-grid, possessing identical nodes and links, to a realistic electric power-grid obtained from the Hungarian electrical database. The last one exhibits node dependent parameters, topologically marginally on the verge of robust networks. We show that too weak quenched heterogeneity, coming solely from the probabilistic self-frequencies of nodes (2D square lattice), is not sufficient for finding power-law distributed cascades. On the other hand, too strong heterogeneity destroys the synchronization of the system. We found agreement with the empirically observed power-law failure size distributions on the US grid, as well as on the Hungarian networks near the synchronization transition point. We have also investigated the consequence of replacing the usual Gaussian self-frequencies to exponential distributed ones, describing renewable energy sources. We found a drop in the steady state synchronization averages, but the cascade size distribution, both for the US and Hungarian systems, remained insensitive and have kept the universal tails, being characterized by the exponent τ ≃ 1.8 . We have also investigated the effect of an instantaneous feedback mechanism in case of the Hungarian power-grid.
Performance Analysis of Cooperative Sensing over Time-Correlated Rayleigh Channels in Vehicular Environments
Authors: Qian Xiaomin , Hao Li
Published: June 2020

Spectrum starvation is a key challenge for wireless services and applications in vehicular networks with serious negative implications for traffic safety and transportation efficiency. As a promising solution, cognitive radio (CR) allows CR-enabled vehicles to access the spectrum holes of primary users (PUs) in an opportunistic manner, but requires a robust sensing mechanism to provide adequate protection for PUs. However, highly dynamic environments make spectrum sensing an increasingly difficult problem. For example, vehicular communications are subject to multipath fading due to vehicle mobility. In this paper, the wireless channels in vehicular environments are considered to be subject to time-correlated Rayleigh fading. To facilitate the analysis, temporal correlation could be classified into complete correlation, partial correlation and complete independence according to the degree of correlation. The performance of cooperative sensing scheme is investigated for soft fusion (SF) and hard fusion (HF) approaches. The simulation results are presented to verify our theoretical analysis for varying conditions and scenarios. The results indicate that the detecting performance could be importantly influenced by channel correlation, which can be improved by vehicles’ cooperation.
Partial Discharge Behaviour of a Protrusion in Gas-Insulated Systems under DC Voltage Stress
Authors: Götz Thomas , Kirchner Hannah , Backhaus Karsten
Published: June 2020

High reliability, independence from environmental conditions, and the compact design of gas-insulated systems will lead to a wide application in future high voltage direct current (HVDC) transmission systems. Reliable operation of these assets can be ensured by applying meaningful and robust partial discharge diagnosis during development tests, acceptance tests, or operation. Therefore, the discharge behavior must be well understood. This paper aims to contribute to this understanding by investigating the partial discharge behavior of a distorted weakly inhomogeneous electrode arrangement in sulfur hexafluoride (SF6) and synthetic air under high DC voltage stress. In order to get a better understanding, the partial discharge current is measured under the variation of the insulation gas pressure, the gas type, the electric field strength, and the voltage polarity. Derived from this, a classification of the different discharge types is performed. As a result, four different discharge types can be categorized depending on the experimental parameters: discharge impulses, discharge impulses with superimposed pulseless discharges, discharge impulses with superimposed pulseless discharges, and subsequent smaller discharges and pulseless discharges. Concluding suggestions for partial discharge measurements under DC voltage stress are given: recommendations for the necessary measurement time, the applied voltage and polarity, and useful measurement techniques.
High-Speed Imaging of Spray Formation and Combustion in an Optical Engine: Effects of Injector Aging and TPGME as a Fuel Additive
Authors: Zhu Xinda , Mannazhi Manu , Palazzo Natascia , Bengtsson Per-Erik , Andersson Öivind
Published: June 2020

High-speed imaging of fuel sprays and combustion is conducted on a light-duty optical engine to investigate the effects of injector aging, with a focus on soot. The spray behaviors of one new and one aged injector are compared using Mie-scattering. In addition to this, the combustion process of a baseline diesel fuel and a blend with TPGME (tripropylene glycol monomethyl ether) are compared using natural luminosity (NL) imaging. TPGME is an oxygenated additive which can be used to reduce soot emissions. X-ray tomography of the two injectors demonstrates that the aging does not lead to significant geometry differences, nor to formation of dense internal nozzle deposits. Both injectors show similar liquid penetration and spreading angle. However, the aged injector shows a prolonged injection and more fuel dribbling after the injection events, leading to a higher injection quantity. The fuel quantity difference shows a larger impact on the NL at low load than the TPGME additive, indicating that the in-cylinder temperature is more important for soot oxidation than oxygen concentration under these conditions. At medium load, the NL is much less sensitive to small temperature variations, while the TPGME is more effective for soot reduction.
Non-Intrusive Load Monitoring (NILM) for Energy Disaggregation Using Soft Computing Techniques
Authors: Puente Cristina , Palacios Rafael , González-Arechavala Yolanda , Sánchez-Úbeda Eugenio Francisco
Published: June 2020

Non-intrusive load monitoring (NILM) has become an important subject of study, since it provides benefits to both consumers and utility companies. The analysis of smart meter signals is useful for identifying consumption patterns and user behaviors, in order to make predictions and optimizations to anticipate the use of electrical appliances at home. However, the problem with this kind of analysis rests in how to isolate individual appliances from an aggregated consumption signal. In this work, we propose an unsupervised disaggregation method based on a controlled dataset obtained using smart meters in a standard household. By using soft computing techniques, the proposed methodology can identify the behavior of each of the devices from aggregated consumption records. In the approach developed in this work, it is possible to detect changes in power levels and to build a box model, consisting of a sequence of rectangles of different heights (power) and widths (time), which is highly adaptable to the real-life working conditions of household appliances. The system was developed and tested using data collected at households in France and the UK (UK-domestic appliance-level electricity (DALE) dataset). The proposed analysis method serves as a basis to be applied to large amounts of data collected by distribution companies with smart meters.
Digging Trajectory Optimization for Cable Shovel Robotic Excavation Based on a Multi-Objective Genetic Algorithm
Authors: Bi Qiushi , Wang Guoqiang , Wang Yongpeng , Yao Zongwei , Hall Robert
Published: June 2020

As one of the most essential earth-moving equipment, cable shovels significantly influence the efficiency and economy in the open-pit mining industry. The optimal digging trajectory planning for each cycle is the base for achieving effective and energy-saving operation, especially for robotic excavation, in which case, the digging trajectory can be precisely tracked. In this paper, to serve the vision of cable shovel automation, a two-phase multi-objective genetic algorithm was established for optimal digging trajectory planning. To be more specific, the optimization took digging time and energy consumption per payload as objects with the constraints of the limitations of the driving system and geometrical conditions. The WK-55-type cable shovel was applied for the validation of the effectiveness of the multi-objective optimization method for digging trajectories. The digging performance of the WK-55 cable shovel was tested in the Anjialing mining site to establish the constraints. Besides, the digging parameters of the material were selected based on the tested data to make the optimization in line with the condition of the real digging operations. The optimization results for different digging conditions indicate that the digging time decreased from an average of 20   s to 10   s after the first phase optimization, and the energy consumption per payload reduced by 13.28% after the second phase optimization, which validated the effectiveness and adaptivity of the optimization algorithm established in this paper.
Ultra-Lightweight Cement Slurry to Seal Wellbore of Poor Wellbore Stability
Authors: Kremieniewski Marcin
Published: June 2020

The article presents the recipe for ultra-lightweight cement slurry for wellbore sealing. In ordinary lightweight cement slurries, the addition of microspheres and a large amount of water are used to maintain rheological parameters. This is a problem because the light particles of microspheres segregate. The cement sheath from such a cement slurry has an anisotropic microstructure and does not stabilize the casing column. In the new ultra-light cement slurry, 60% aluminosilicate microspheres and a large amount of water were used. The ultra-light weight slurry has a density below 1.2 g/cm3. This cement slurry does not segregates and in the sedimentation stability test has the same density at all measuring points. The cement slurry, despite the larger amount of water, has the same filtration as the control sample. The technological parameters of the slurry are adapted to the borehole conditions. Cement slurry is a ready-made application to seal a borehole with poor wellbore stability under conditions of 40 °C and 10 MPa pressure. The cement sheath structure in the wellbore after binding is homogeneous. The use of such slurry allows to reduce the risk of wall damage in wellbores of poor stability.
Allergenicity of Fermented Foods: Emphasis on Seeds Protein-Based Products
Authors: El Mecherfi Kamel-Eddine , Todorov Svetoslav Dimitrov , Cavalcanti de Albuquerque Marcela Albuquerque , Denery-Papini Sandra , Lupi Roberta , Haertlé Thomas , Dora Gombossy de Melo Franco Bernadette , Larré Colette
Published: June 2020

Food allergy is an IgE-mediated abnormal response to otherwise harmless food proteins, affecting between 5% and 10% of the world preschool children population and 1% to 5% adults. Several physical, chemical, and biotechnological approaches have been used to reduce the allergenicity of food allergens. Fermentation processes that contribute to technological and desirable changes in taste, flavor, digestibility, and texture of food products constitute one of these approaches. Lactic acid bacteria (LAB), used as starter cultures in dairy products, are a subject of increasing interest in fermentation of plant proteins. However, the studies designed to assess the impact of LAB on reduction of allergenicity of seed proteins are at an early stage. This review presents the current knowledge on food fermentation, with a focus on seed proteins that are increasingly used as ingredients, and its impacts on food potential allergenicity.
A Pea (Pisum sativum L.) Seed Vicilins Hydrolysate Exhibits PPARγ Ligand Activity and Modulates Adipocyte Differentiation in a 3T3-L1 Cell Culture Model
Authors: Ruiz Raquel , Olías Raquel , Clemente Alfonso , Rubio Luis A.
Published: June 2020

Legume consumption has been reported to induce beneficial effects on obesity-associated metabolic disorders, but the underlying mechanisms have not been fully clarified. In the current work, pea (Pisum sativum L.) seed meal proteins (albumins, legumins and vicilins) were isolated, submitted to a simulated gastrointestinal digestion, and the effects of their hydrolysates (pea albumins hydrolysates (PAH), pea legumins hydrolysates (PLH) and pea vicilin hydrolysates (PVH), respectively) on 3T3-L1 murine pre-adipocytes were investigated. The pea vicilin hydrolysate (PVH), but not native pea vicilins, increased lipid accumulation during adipocyte differentiation. PVH also increased the mRNA expression levels of the adipocyte fatty acid-binding protein (aP2) and decreased that of pre-adipocyte factor-1 (Pref-1) (a pre-adipocyte marker gene), suggesting that PVH promotes adipocyte differentiation. Moreover, PVH induced adiponectin and insulin-responsive glucose transporter 4 (GLUT4) and stimulated glucose uptake. The expression levels of peroxisome proliferator-activated receptor γ (PPARγ), a key regulator of adipocyte differentiation, were up-regulated in 3T3-L1 cells treated with PVH during adipocyte differentiation. Finally, PVH exhibited PPARγ ligand activity. Lactalbumin or other pea hydrolysates (PAH, PLH) did not exhibit such effects. These findings show that PVH stimulates adipocyte differentiation via, at least in part, the up-regulation of PPARγ expression levels and ligand activity. These effects of PVH might be relevant in the context of the beneficial health effects of legume consumption in obesity-associated metabolic disorders.
Natural Phenolic Compounds for the Control of Oxidation, Bacterial Spoilage, and Foodborne Pathogens in Meat
Authors: Kalogianni Aphrodite I. , Lazou Thomai , Bossis Ioannis , Gelasakis Athanasios I.
Published: June 2020

Alternative technologies for long-term preservation, quality assurance, and safety of meat are continuously pursued by the food industry to satisfy the demands of modern consumers for nutritious and healthy meat-based products. Naturally occurring phenolic compounds are considered promising substances by the meat industry for their antioxidant and antimicrobial properties, while consumers seem to embrace them for their claimed health benefits. Despite the numerous in vitro and in situ studies demonstrating their beneficial effects against meat oxidation, spoilage, and foodborne pathogens, wide application and commercialization has not been yet achieved. Major obstacles are still the scarcity of legislative framework, the large variety of meat-based products and targeted pathogens, the limited number of case-specific application protocols and the questionable universal efficiency of the applied ones. The objectives of the present review are (i) to summarize the current knowledge about the applications of naturally occurring phenols in meat and meat-based products, emphasizing the mechanisms, determinants, and spectrum of their antioxidant and antimicrobial activity; (ii) to present state-of-the-art technologies utilized for the application of phenolic compounds in meat systems; and (iii) to discuss relevant regulation, limitations, perspectives, and future challenges for their mass industrial use.
Investigation of Geological Anomalies at Pile Foundation Location in Urban Karst Areas Using Single Borehole Radar
Authors: Liu Liu , Shi Zhenming , Peng Ming , Tsoflias Georgios P.
Published: June 2020

Karst geological anomalies at pile locations significantly affect the bearing capacity and construction safety of the piles, posing a significant challenge for urbanization. Borehole geophysical methods are required to extend the detection range and identify karst voids that are at pole locations and near drilled boreholes. In this paper, we developed a near offset and small diameter single borehole ground penetration radar (GPR) prototype. A signal processing method combining complex signal analysis by Hilbert transform (HT) and medium filtering was suggested to differentiate the weak backscattered wave from borehole background noise. A controlled horizontal borehole experiment was used to demonstrate the applicability of the prototype and the advantages of the signal analysis method prior to application in a real project. The controlled test presented three typical wave events corresponding to a soil–rock interface, rock fractures, and karst voids. Field tests were conducted at a freeway bridge extension project in an urban karst area. Multiple karst voids, sinkholes, rock fractures, and integrated bedrock were identified by analysis of four typical detection scenarios. The remediation of the karst voids and a rotary bored piling with real-time steel casing construction strategy were designed based on the investigation results. The construction feedback demonstrates that single borehole radar detection is effective for the investigation of anomalies at pile locations in urban karst areas.