bluuebunny/crossref_metadata_2025 huggingface dataset:
Cobalt can fully recover the phenotypes related to zinc deficiency inSalmonellaTyphimurium
Authors: Ammendola Serena , Ciavardelli Domenico , Consalvo Ada , Battistoni Andrea
Published: October 2020

Cobalt is an essential element for living systems, which, however, make very limited use of this metal, using it mainly in cobalamin-containing enzymes. The reduced use of cobalt compared to other transition metals is generally attributed to the potential toxicity of this element. In this work, we demonstrate that cobalt not only does not have an obvious toxic effect on Salmonella Typhimurium, but that it can efficiently compensate for zinc deficiency in a znuABC deleted strain. In fact, cobalt, but not cobalamin supplementation, rescued all major phenotypic defects of the znuABC strain, including the reduced ability to grow and swim in zinc-deficient media and the high susceptibility to hydrogen peroxide stress. Growth in a cobalt-supplemented defined medium led to the accumulation of large amounts of cobalt both in the wild type and in the znuABC strain. These data suggest that atoms of cobalt may be incorporated in bacterial proteins in place of zinc, ensuring their functionality. In support of this hypothesis we have shown that, in vivo, cobalt can accumulate in ribosomes and replace zinc in a periplasmic Cu,Zn superoxide dismutase (SodCII). Finally, we provide evidence of the ability of cobalt to modulate the intracellular concentration of zinc-regulated proteins (ZnuA, ZinT, and SodCII). Although some observations suggest that in some proteins the replacement of zinc with cobalt can lead to subtle structural changes, the data reported in this study indicate that Salmonella has the ability to use cobalt instead of zinc, without evident harmful effects for cell physiology.
An insight into the molecular structures, theoretical calculation and catalytic activities of novel heterotrinuclear [CuII2CeIII] and heterohexanuclear [CuII4YIII2] bis(salamo)-based complexes
Authors: Chen Zhuang-Zhuang , Zhang Wen-Ze , Zhang Ting , Zhang Yang , Dong Wen-Kui
Published: October 2020

Two heteropolynuclear complexes, [CuII2CeIII] [Cu2(L)Ce(NO3)3] and [{Cu2(L)Y(NO3)2(μ-AcO)}{Cu2(L)Y(NO3)2(μ-NO3)(CH3OH)}]·4CH3OH, were synthesized. It was found that only the [CuII2CeIII] complex showed high catecholase and benzoxazinone synthase like catalytic activity.
Solid solution ZnW1−xMoxO4 for enhanced photocatalytic H2 evolution
Authors: Tang Liang , Zhu Min , Chen Wenqian , Tang Suwen , Feng Yuan , Wang Peng , Liu Xiaonan , Foo Mawlin , Wu Minghong
Published: October 2020

ZnW1−xMoxO4 and n–n heterojunction ZnW1−xMoxO4/CdS complexes exhibited photocatalytic hydrogen evolution activity superior to that of pristine ZnWO4.
Supramolecular nanomotors with “pH taxis” for active drug delivery in the tumor microenvironment
Authors: Mathesh Motilal , Sun Jiawei , van der Sandt Frans , Wilson Daniela A.
Published: October 2020

Supramolecular architecture-based truly “pH taxis” exhibiting nanomotors are fabricated byin-situgrown CaCO3particles, which can sense the endogenously present pH gradient in HeLa cells making them suitable for targeted drug delivery applications.
Gold-catalyzed homo- and cross-annulation of alkynyl carboxylic acids: a facile access to substituted 4-hydroxy 2H-pyrones and total synthesis of pseudopyronine A
Authors: Gayyur  , Choudhary Shivani , Saxena Anchal , Ghosh Nayan
Published: October 2020

A single-step protocol for the synthesis of 3,6-disubstituted 4-hydroxy 2H-pyrones under goldcatalyzed conditions is developed from alkynyl acids. The total synthesis of pseudopyronine A is achieved with an overall 24% yield.
“Double guarantee mechanism” of Ca2+-intercalation and rGO-integration ensures hydrated vanadium oxide with high performance for aqueous zinc-ion batteries
Authors: Hu Tao , Feng Ziyi , Zhang Yifu , Liu Yanyan , Sun Jingjing , Zheng Jiqi , Jiang Hanmei , Wang Peng , Dong Xueying , Meng Changgong
Published: October 2020

Ca2+-Intercalated hydrated V2O5/rGO (CaVOH/rGO) is synthesized via a facile hydrothermal process and applied as a cathode for ARZIBs with an admirable specific capacity (409 mA h g−1 at 0.05 A g−1) and excellent energy density (381 W h kg−1).
Luminescence response mode and chemical sensing mechanism for lanthanide-functionalized metal–organic framework hybrids
Authors: Yan Bing
Published: October 2020

This comprehensive review systematically summarizes the luminescence response mode and chemical sensing mechanism for lanthanide-functionalized MOF hybrids (abbreviated as LnFMOFH).
N-(2,3,5,6-Tetrafluoropyridyl)sulfoximines: synthesis, X-ray crystallography, and halogen bonding
Authors: Schumacher Christian , Fergen Hannah , Puttreddy Rakesh , Truong Khai-Nghi , Rinesch Torsten , Rissanen Kari , Bolm Carsten
Published: October 2020

N-(Tetrafluoropyridyl)sulfoximines are obtained fromNH-sulfoximines and pentafluoropyridine under solution-based or mechanochemical conditions, and the solid-state structures of 26 products have been determined by X-ray diffraction analysis.
A green synthesis of nanocatalysts based on reduced graphene oxide/magnetic nanoparticles for the degradation of Acid Red 1
Authors: Sadegh Fatemeh , Politakos Nikolaos , González de San Román Estibaliz , Sanz Oihane , Perez-Miqueo Iñigo , Moya Sergio Enrique , Tomovska Radmila
Published: October 2020

Fenton reaction nanocatalysts made of reduced graphene oxide–magnetic nanoparticle 3D composite aerogels for the elimination of organic dyes from aqueous solution.
Changes of pro-inflammatory and anti-inflammatory macrophages after peripheral nerve injury
Authors: Zhang Fuchao , Miao Yang , Liu Qianyan , Li Shiying , He Jianghong
Published: October 2020

The temporal patterns of pro-inflammatory and anti-inflammatory macrophages after peripheral nerve injury.
A DNA nanopillar as a scaffold to regulate the ratio and distance of mimic enzymes for an efficient cascade catalytic platform
Authors: Kou Bei-Bei , Chai Ya-Qin , Yuan Ya-Li , Yuan Ruo
Published: October 2020

A rigid 3D DNA nanopillar was used to investigate the influence of spatial organization on the cascade activity in multienzyme systems, realizing controllable regulation of the mimic enzyme ratio and spacing for efficient cascade catalytic platform.
Deep in blue with green chemistry: influence of solvent and chain length on the behaviour of N- and N,N′- alkyl indigo derivatives
Authors: Pinheiro Daniela , Pineiro Marta , Galvão Adelino M. , Seixas de Melo J. Sérgio
Published: October 2020

Using green chemistry procedures the synthesis of N- and N,N′-alkyl indigo derivatives was undertaken and the effect of the alkyl chain length on the spectral (including color) and photophysical properties of the compounds explored.
Cation recognition on a fullerene-based macrocycle
Authors: Hashikawa Yoshifumi , Murata Yasujiro
Published: October 2020

A fullerene-based Lewis-basic macrocyclic ligand underwent complexation with alkali-metal ions in 1 : 1 and 1 : 2 fashions, resulting in considerable perturbation to absorption properties as well as the potential surface inside the cage.
Asymmetric construction of pyrido[1,2-a]-1H-indole derivatives via a gold-catalyzed cycloisomerization
Authors: Jiang Feng , Fu Chunling , Ma Shengming
Published: October 2020

We reported an IPrAuCl/AgSbF6-catalyzed cycloisomerization of enantio-enriched N-1,3-disubstituted allenylindoles affording optically active pyrido[1,2-a]-1H-indoles in excellent yields and enantioselectivities.
A multicomponent interconnected composite paper for triple-mode sensors and flexible micro-supercapacitors
Authors: Wei Jing , Teng Youchao , Meng Taotao , Bu Xiangting , Du Hongbiao , Li Dagang
Published: October 2020

A multicomponent interconnected composite paper with mechanical robustness, reliable stimulus responsivity and brilliant electrochemical capacitance for human motion/healthcare monitoring.
Two-dimensional molybdenum carbides: active electrocatalysts for the nitrogen reduction reaction
Authors: Zhang Bikun , Zhou Jian , Elliott Stephen R. , Sun Zhimei
Published: October 2020

1T-Mo2C, 2H-Mo2C and MoC2 (edge) exhibit high nitrogen reduction reaction (NRR) catalytic activity.
Synergistically ultrahigh energy storage density and efficiency in designed sandwich-structured poly(vinylidene fluoride)-based flexible composite films induced by doping Na0.5Bi0.5TiO3 whiskers
Authors: Lin Ying , Zhang Yongjing , Zhan Shili , Sun Chuang , Hu Guangliang , Yang Haibo , Yuan Qibin
Published: October 2020

Newly designed sandwich-structured poly(vinylidene fluoride)-based composite films with Na0.5Bi0.5TiO3 whiskers give rise to ultrahigh discharged energy density and efficiency.
Dependence of phase transitions on halide ratio in inorganic CsPb(BrxI1−x)3 perovskite thin films obtained from high-throughput experimentation
Authors: Näsström H. , Becker P. , Márquez J. A. , Shargaieva O. , Mainz R. , Unger E. , Unold T.
Published: October 2020

The heating and cooling phase diagram of CsPb(BrxI1−x)3 is determined by combinatorial synthesis and high throughput X-ray characterization.
Reducing the surface defects of Ta3N5 photoanode towards enhanced photoelectrochemical water oxidation
Authors: Shao Chenyi , Chen Ruotian , Zhao Yongle , Li Zheng , Zong Xu , Li Can
Published: October 2020

Ta3N5 photoanodes with reduced surface defects were obtained through the nitridation of a two-step-flame-heating-derived Ta2O5 precursor and exhibited enhanced photoelectrochemical performance.
Black phosphorus quantum dots encapsulated in anionic waterborne polyurethane nanoparticles for enhancing stability and reactive oxygen species generation for cancer PDT/PTT therapy
Authors: Lu Fengying , Li Zhengjun , Kang Yong , Su Zhiguo , Yu Rong , Zhang Songping
Published: October 2020

Encapsulation of BPQDs inside biocompatible anionic WPU nanoparticles improved both the stability and the ROS generation of BPQD due to special electrochemical double layer of WPU, thus enabled efficient PDT/PTT cancer treatments.
Correction: Biocompatible nitrogen-doped carbon dots: synthesis, characterization, and application
Authors: Park Yoonsang , Kim Yujin , Chang Heemin , Won Sungyeon , Kim Hyemin , Kwon Woosung
Published: October 2020

Correction for ‘Biocompatible nitrogen-doped carbon dots: synthesis, characterization, and application’ by Yoonsang Park et al., J. Mater. Chem. B, 2020, DOI: 10.1039/d0tb01334j.
High-performance near-infrared organic phototransistors based on diketopyrrolopyrrole conjugated polymers with partial removal of long branched alkyl side chains
Authors: Tang Yu , Ge Weijie , Deng Ping , Zhang Qiaoming , Liao Yingjie , Xiong Zuhong , Lan Weixia , Wei Bin , Lei Yanlian
Published: October 2020

Near-infrared (NIR) phototransistors based on diketopyrrolopyrrole polymers with partial removal of side chains are reported with improved NIR photoresponses, which take advantage of both strengthened NIR absorption and improved charge transport.
Gamma-ray irradiation-induced oxidation and disproportionation at the amorphous SiO2/Si interfaces
Authors: Meng Dechao , Lan Mu , Yang Zeng-hui , Hu Shouliang , Zhang Guanghui , Liang Chuanhui , Zhan Haoran , Liu Jiang , Li Ming , Zhou Hang , Zuo Xu , Song Yu , Wei Su-Huai
Published: October 2020

Distinct interfacial structure changes, including oxidation and disproportionation, have been found to be the main response to the Mrad dose gamma ray irradiation for SiO2/Si films.
Enhanced performance of near-infrared photodetectors based on InGaAs nanowires enabled by a two-step growth method
Authors: Zhang Heng , Wang Wei , Yip SenPo , Li Dapan , Li Fangzhou , Lan Changyong , Wang Fei , Liu Chuntai , Ho Johnny C.
Published: October 2020

Substantial performance enhancement of near-infrared photodetectors can be achieved by utilizing two-step chemical vapor deposition-grown InGaAs nanowires as device channels.
Freestanding single-crystal Ni0.5Zn0.5Fe2O4 ferrite membranes with controllable enhanced magnetic properties for flexible RF/microwave applications
Authors: Yao Mouteng , Li Yaojin , Tian Bian , Mao Qi , Dong Guohua , Cheng Yuxin , Hou Weixiao , Zhao Yanan , Wang Tian , Zhao Yifan , Jiang Zhuangde , Liu Ming , Zhou Ziyao
Published: October 2020

Flexible epitaxial ferrite thin films are crucial for flexible RF/microwave devices; however, they are difficult to be fabricated due to critical growth conditions.
Pillar[5]arene-based supramolecular assemblies with two-step sequential fluorescence enhancement for mitochondria-targeted cell imaging
Authors: Guo Hao , Yan Xin , Lu Bing , Wang Jin , Yuan Xiaolei , Han Ying , Ding Yue , Wang Yang , Yan Chaoguo , Yao Yong
Published: October 2020

Two-step sequential fluorescence emission enhanced supramolecular nanoparticles are constructed from pillar[5]arene based host–guest interaction and a linear amphiphile. These supramolecular nanoparticles can be applied in mitochondria-targeted live cell imaging.
Highly flexible dual-mode anti-counterfeiting designs based on tunable multi-band emissions and afterglow from chromium-doped aluminates
Authors: Yang Huanxin , Zhao Weiren , Song Enhai , Yun Rui , Huang Hao , Song Jingzhou , Zhong Jiyou , Zhang Hui , Nie Zhaogang , Li Yang
Published: October 2020

Dual-mode anti-counterfeiting design based on fluorescence and afterglow.
Progress in Education of Children With Disabilities in Zambia
Authors: Peele Muchinka Mbewe , Gill Cindy , Wainscott Sarah
Published: October 2020

Purpose

The purpose of this review article is to review the progress made in the treatment and education of persons with disabilities in Zambia, to identify barriers that have hindered change and initiatives that have facilitated positive changes in Zambia, and to highlight the initial steps toward the establishment of the profession of speech-language pathology in Zambia.

Conclusions

There have been remarkable strides in the education of children with disabilities and the establishment of support for persons with disabilities since the Republic of Zambia became an independent nation in 1964. Zambia's limited resources, understanding of disabilities, and cultural and social barriers have hampered efforts to provide special services to children. Despite these challenges, many policies have been adopted and laws passed to protect the rights of those with disabilities, including access to quality equitable and inclusive education programs. Though implementation of the stated ideals has been difficult, and poverty continues in many areas, preparation of special education teachers and inclusion practices has improved. One vital service for children with disabilities, speech/language therapy, remains outside the new provisions. Speech therapy is not currently provided in the schools and is rarely available elsewhere. Though there are currently no Zambian college or university preparation programs for speech therapists, plans to bring speech pathology to Zambia are underway.
Modelling large scale camera networks for identification and tracking: an abstract framework
Authors: Mohan Lakshmi , Menon Vivek
Published: October 2020

In this study, the authors discuss a novel approach for multi‐camera‐based unobtrusive identification and tracking of occupants in wide‐area, multi‐building scenarios. Considering the scalability issues in adopting a centralised approach to monitor wide‐area scenarios, they proposed a distributed approach to occupant identification and tracking. The key technical idea underlying their approach is to abstract a wide‐area indoor surveillance environment using a distributed state transition system (DSTS) model, which in turn is composed of independent building‐specific state transition systems, coordinating and collaborating with each other. This study presents the details of their DSTS model and examines the temporal ordering of recognition events within the DSTS for ensuring accurate state information and responses to spatio–temporal queries. They also provide an experimental evaluation of the performance of their model using precision‐recall metrics. Their conclusion is that the DSTS model serves as an efficient mechanism for tracking occupants in wide‐area, multi‐building scenarios monitored by camera networks.
Detection of power swing and prevention of mal‐operation of distance relay using compressed sensing theory
Authors: Taheri Behrooz , Sedighizadeh Mostafa
Published: October 2020

Power system protection has become an essential challenge with the development of the power system. This study presents a new method in detecting a power swing based on compressed sensing. The proposed method is tested on the IEEE 39‐bus network using MATLAB and DIgSILENT software. The simulation results show that the presented method is able to detect and differentiate between different types of power system conditions: stable, unstable, and multi‐mode power swings. In addition, this method has a high speed in detecting the simultaneous fault with the power swing phenomenon. Moreover, the proposed method is capable of operating correctly despite noise signal in the system. This study has proven that the suggested method outperforms most of the existing methods as shown in the comparison section.
Transient DC bias suppression of three‐port isolated DC–DC converter
Authors: Tu Chunming , Yu Xueping , Xiao Fan , Liu Bei , Guo Qi
Published: October 2020

Three‐port isolated dc–dc converter, as an active exploration and trial of photovoltaic access to dc distribution system, has the advantages of superior control flexibility and high reliability. Due to the changes in the phase‐shift (PS) angle, the conventional PS control method cause transient dc bias in inductor current and magnetisation current, further increasing the current stress of switches and threatening the safe operation of the converter. Based on superposition theorem analysis, this study discusses the formation mechanism of transient dc bias, constructs a mathematical model of drive signals, and proposes two typical combination strategies of drive signals. The proposed method can simultaneously suppress the dc bias of port inductor and transformer magnetisation inductor in one switching cycle by changing the duty ratio of square wave voltage or adding the zero‐voltage phase related to the PS angle. By simulating the PS angle change and output power fluctuation, the dynamic characteristics under conventional PS control and the proposed strategy are compared and discussed. The simulation and experimental waveforms show that the proposed method is not only suitable for the multi‐step step change of PS angle, but also sufficient for the continuous evolution of the PS angle.
Performance enhancement of IEEE 802.15.4 by employing RTS/CTS and frame concatenation
Authors: Barroca Norberto , Velez Fernando J. , Borges Luís M. , Chatzimisios Periklis
Published: October 2020

IEEE 802.15.4 has been widely accepted as the de facto standard for wireless sensor networks (WSNs). However, as in their current solutions for medium access control (MAC) sub‐layer protocols, channel efficiency has a margin for improvement, in this study, the authors evaluate the IEEE 802.15.4 MAC sub‐layer performance by proposing to use the request‐/clear‐to‐send (RTS/CTS) combined with frame concatenation and block acknowledgement (BACK) mechanism to optimise the channel use. The proposed solutions are studied in a distributed scenario with single‐destination and single‐rate frame aggregation. The throughput and delay performance is mathematically derived under channel environments without/with transmission errors for both the chirp spread spectrum and direct sequence spread spectrum physical layers for the 2.4 GHz Industrial, Scientific and Medical band. Simulation results successfully verify the authors’ proposed analytical model. For more than seven TX (aggregated frames) all the MAC sub‐layer protocols employing RTS/CTS with frame concatenation (including sensor BACK MAC) allow for optimising channel use in WSNs, corresponding to 18–74% improvement in the maximum average throughput and minimum average delay, together with 3.3–14.1% decrease in energy consumption.
Photoelectric properties of low temperature solution‐processed three‐dimensional Bi2S3 crystals
Authors: Yang Chunyan , Sun Yingying , Zhang Yaohua , Xiong Fei , Li Jianfeng , Zhang Peng , Tong Junfeng , Xia Yangjun
Published: October 2020

Three‐dimensional Bi2S3 with different morphology of flower‐like, waxberry like and hydrangea like on the tin‐doped indium oxide substrate has been produced from one‐step aqueous solution at low temperature (40–70°C) and fixed pH of 0.81 for 24 h. The UV–vis measurement showed that the absorption spectrums of obtained Bi2S3 crystals were occurred blue shift compared to the bulk orthorhombic Bi2S3(1.3 eV). With the increase in temperature, the crystallinity of Bi2S3 films was gradually improved. When the temperature went to 55°C, the best conductivity was obtained.
Onboard catalogue of known X-ray sources for SVOM/ECLAIRs
Authors: Dagoneau N. , Schanne S. , Rodriguez J. , Atteia J.-L. , Cordier B.
Published: October 2020

The SVOM mission currently under development will carry various instruments, and in particular the coded-mask telescope ECLAIRs, with a large field of view of about 2 sr, operating in the 4–150 keV energy band. The main goal of ECLAIRs is to detect high-energy transients such as gamma-ray bursts. Its onboard trigger software will search for new hard X-ray sources appearing in the sky, as well as peculiar behaviour (e.g. strong outbursts) from known sources, in order to repoint the satellite to perform follow-up observations with its onboard narrow-field-of-view instruments. The presence of known X-ray sources must be disentangled from the appearance of new sources. This is done with the help of an onboard source catalogue, which we present in this paper. As an input we use catalogues of X-ray sources detected by Swift/BAT and MAXI/GSC and we study the influence of the sources on ECLAIRs’ background level and on the quality of the sky-image reconstruction process. We show that the influence of the sources depends on the pointing direction on the sky, on the energy band, and on the exposure time. In the Galactic centre, the contribution from known sources largely dominates the cosmic X-ray background, which is, on the contrary, the main background in sky regions lacking strong sources. We also demonstrate the need to clean the contributions of these sources in order to maintain a low noise level in the sky images and to maintain a low threshold for the detection of new sources without introducing false triggers. We briefly describe one of our cleaning methods and its challenges. Finally, we present the overall structure of the onboard catalogue and the way it will be used to perform the source cleaning and disentangle detections of new sources from outbursts of known sources.
Wine traceability and authenticity: approaches for geographical origin, variety and vintage assessment
Authors: Zava Andrea , Sebastião Pedro J. , Catarino Sofia
Published: October 2020

The aim of this work is to identify and discuss physicochemical wine characteristics, to provide to some extent a link to the vintage, variety, and/or geographical origin. Bibliographic datasets were attempted to provide the main information for topic comprehension, identifying the sources of wine compositional variability and how these can be expressed in terms of the belonging categories. Since all the environmental and technological conditions which vineyard and wine are subjected are rarely known, different sources were inspected. Great importance was given to the study of isotopic composition because of its importance in food frauds detection history. The interaction of the plant genotype with the environmental conditions of the vintage is the main responsible for the wines organic and inorganic fraction variability in terms of both total and relative content. This phenotypical expression, together with human and abiotic variability sources, has been examined since it contains to some extent the information for the discrimination of wines according to their category. Recently, new proton nuclear magnetic resonance (1H NMR) spectroscopy techniques have been under study and, used concurrently to chemometric data management procedures, showed to be an interesting and promising tool for wine characterization according to both vintage and variety.
Heading Towards 100% of Renewable Energy Sources Fraction: a critical overview on Smart Energy Systems planning and flexibility measures
Authors: Pastore Lorenzo Mario , Lo Basso Gianluigi , Sforzini Matteo , de Santoli Livio
Published: October 2020

The growing penetration of non-programmable energy sources will largely contribute to intensify the renewable capacity firming issues. Providing a higher systems flexibility, i.e. the ability to match the supply and the demand sides as much as possible, is the main challenge to cope with, by adopting new energy planning paradigms. In this framework, different combined strategies, aiming at efficiently integrating that large amount of variable RES (VRES), have to be implemented. In the recent years, the Smart Energy Systems (SES) concept has been introduced to overcome the single-sector approach, promoting a holistic and integrated vision. By that approach, it is possible to exploit synergies between different energy sectors so as to identify the best technical options to globally reduce the primary fossil energy consumption. Starting from a quantitative and qualitative analysis of the most recent international studies dealing with the SES approach, the aim of this paper is to critically review and analyse the role of the main potential flexibility measures applied in the energy planning sector. In detail, Power-to-X and Demand Side Management (DSM) application have been considered, highlighting strengths and weaknesses of such strategies to accomplish the ambitious target of 100% renewable. From this literature review, it emerges how a single strategy adoption is not enough to guarantee the required flexibility level for the whole energy system. Indeed, the best configuration can be attained by integrating different options matching all the external constraints.
Optimal sizing of a distributed energy system with thermal load electrification
Authors: Lubello Pietro , Vaccaro Guglielmo , Carcasci Carlo
Published: October 2020

Renewable energy systems (RES) are currently being deployed on a large scale to meet the ambitious sustainable development goals for the next decades. A higher penetration of sustainable means of power production passes through the diffusion of RES-based distributed energy systems. The hybridization of such systems and their integration with Energy Storage Systems (ESS) can help improve reliability and level the mismatch between power production and consumption. In this paper, a novel modular tool for the simulation of distributed energy systems is presented by means of its application to a case study. The considered system is composed by PV modules, ESS and heat pumps. The optimal sizing of the components for self-consumption has been obtained through an electricity production cost minimization. A comparison between two different configurations has been conducted: in the first case, the thermal load is completely satisfied by a natural gas-fired boiler, while in the latter case, part of the thermal load is satisfied by a heat pump. The results have highlighted the impact of ESS on the economics of distributed energy systems and how the investment in such systems, in conditions similar to the case study, can be more easily sustained if a share of the total energy consumption of the unit is shifted from the thermal to the electrical part.
Minimalist RC network for building energy simulations: a case study based on OpenBPS
Authors: Colombo Paola , Scoccia Rossano , Aprile Marcello , Motta Mario , Mazzarella Livio
Published: October 2020

Robust and fast dynamic simulation tools are crucial for the sizing of the components of complex HVAC system and for the definition of the optimal control strategy. In this work, a first step towards the extension of OpenBPS, a new building energy performance simulation tool, to the dynamic simulation of HVAC systems is presented. In particular, the building model has been reduced to a Resistors-Capacitors (RC) network and OpenBPS has been used for the identification of the parameters of the grey-box model. Indeed, the reduction and identification of the building energy model is the fundamental step for extension of the tool to perform dynamic simulations of complex HVAC systems with the advantage of low computational load, thus suitable for parametric yearly simulations and control strategy analyses. The toolkit of identification and cross validation of a minimalist RC network is presented in this paper, discussing the results obtained for a case study building under study in the European project Heat4Cool founded by Horizon 2020 programme. The identified model demonstrated a good accuracy in the estimation of the room temperature under different tests settings representative of the actual operating conditions.
Urban Abacus of Building Energy Performances: a methodological approach
Authors: Pili Stefano , Fois Valeria , Loria Eusebio , Frau Caterina , Orrù Pier Francesco
Published: October 2020

This paper presents a methodological approach to develop the tool “Urban Abacus of Building Energy performances (Abaco URbano Energetico degli Edifci – AUREE)” for supporting the renovation and energy efficiency enhancement of urban building heritage. The AUREE tool will be based on a Web – GIS GeoBlog portal with some customized interfaces aimed to share the knowledge on urban building heritage and promote the participation of the stakeholders of the urban community. The tool improves citizen and stakeholders awareness on building energy efficiency issues and facilitates the linkage between demand and offer for building companies services via the integration of two main elements: the first is a knowledge layer that represents the actual state of the energy performance of urban building heritage and the second is a spatial based Abacus of the more common building characteristics (structures, plants, uses, ..) and energy retrofitting and renovation technologies. After a touch on the theoretical context, this paper presents a summary of the AUREE general framework and focuses on the methodological approach of the Urban Abacus. The data structure integrates an Urban Building Energy Model (UBEM) in order to support on the energy retrofitting scenario analysis at the level of single building and also for a group of them (city block, district, city). At the end of the paper the furthers research steps have been pointed
Using natural fibre insulators on green roofs: some considerations
Authors: Fabbri Kristian , Barbieri Fabrizio , Merli Francesca
Published: October 2020

This study focuses on the application of coconut fibre insulators, an insulating material rarely utilized in the Mediterranean context. Despite its undoubted thermal performance, some queries are related with of his thermo-hygrometric behavior. More precisely, during the use of coconut for covering building for realizing green roofs, which represent a technological solution often adopted in the case of sustainable buildings or nearly zero energy building. Green roofs represent a valid constructive solution with high thermal performances, adopted in existing and new buildings. This paper investigates the thermo-hygrometric behavior of the concrete and Cross Laminated Timbre slabs, insulated with coconut fibreboards (CF) such as an alternative synthetic insulator, referred to a series of different green roofs scenarios. The results show that coconut fibre insulations are equally comparable to natural and synthetic materials. Therefore, coconut fibre could represent a good chance for realization of green roof having high thermal performance and hygrothermal behavior in the same time. This material could be an alternative solution to the normal synthetic materials actually used, in a perspective of sustainable architecture.
Energy flexibility in residential buildings clusters
Authors: Mugnini Alice , Polonara Fabio , Arteconi Alessia
Published: October 2020

The building sector represents one of the most energy-consuming worldwide and a great part of its consumption is accounted for residential demand for space heating and cooling. Although it is necessary to promote the buildings energy efficiency, energy flexibility is also of paramount importance to optimize the balance between demand and supply. In fact, an energy flexible building is defined as able to change, in a planned manner, the shape of its energy demand curve, electrical and thermal, while the comfort of the end-users is still guaranteed. Objective of this work is to exploit the energy demand management ability of different buildings composing a cluster, when their aggregated demand derived from electric heating systems (i.e. heat pumps) is subject to demand response (DR) strategies. Users with different occupancy profile are considered. By supposing to be able to activate the energy flexibility of the single building with thermostatic load control, different scenarios of cluster composition are evaluated in order to provide guidelines to implement optimal strategies for energy flexibility exploitation without drawback effects connected to the event.
A multiple linear regression approach to correlate the Indoor Environmental Factors to the global comfort in a Zero-Energy building
Authors: Danza Ludovico , Belussi Lorenzo , Salamone Francesco
Published: October 2020

The quality of the indoor environment, in terms of thermal, lighting, air and acoustic quality, grouped in the Indoor Environmental Quality (IEQ) concept, plays a key role in occupants’ wellbeing and satisfaction. Only in recent years IEQ has been investigated as a whole. Today, IEQ occupies the same place of energy efficiency in the design of buildings, especially those with high performance level as the Zero-Energy Buildings (ZEB). The research deals with an experimental campaign during the cooling season carried out in a ZEB laboratory that involved 100 participants aimed at evaluating the IEQ and the indoor environments (e.g. thermal and air quality). The test consists in a survey, during which each participant is required to answer a questionnaire about how he feels the indoor environment. The experimental campaign was completed with a monitoring activity aimed at detecting the main environmental variables that can affect the participants’ answers. Collected data were treated with regression techniques to highlight possible relationships between them. The results show how in a building with high levels of energy performances the air quality plays a key role on occupants’ evaluation.
Performance analysis of an on-site hydrogen facility for fuel cell trains
Authors: Piraino Francesco , Genovese Matteo , Fragiacomo Petronilla
Published: October 2020

Fuel cell technologies and hydrogen can represent a potential and powerful enabler for replacing traditional diesel vehicles, especially in railways. In this train of thought, the present paper aims to investigate a fuel cell hybrid powertrain for a regional route. The main powertrain components are numerically modeled and the railway operations are simulated. The results achieved, in terms of power demand, efficiency and hydrogen consumption, are discussed and they are useful for properly sizing the refueling system. As a matter of fact, the train will be fueled with compressed hydrogen, produced on-site at a hydrogen central depot, where a hydrogen refueling station is thought to be installed. The hydrogen generation unit is considered to be a PEM unit, operating at 353 K and 20 bar. The produced hydrogen is then compressed by mean of a volumetric compressor and then stored in hydrogen tank type II, at 350 bar. The dispensing scheduling is based on the daily hydrogen demand required by the fuel cell-based train route, according to the railway timetable.

The system is indeed investigated from a technical point of view, proving the integration of such systems to represent a clean, sustainable, and flexible option.
A Practical Design Approach to Improve the Charging Efficiency of a Small Two-Stroke High Speed Engine Based on Basic CFD
Authors: Masi Massimo , Pregrasso Matteo , Gobbato Paolo
Published: October 2020

The paper deals with the optimisation of the charging efficiency in a small two-stroke high-speed engine according to well-established design guidelines. The aim is to present the method successfully used in the preliminary screening of the performance improvement attainable in a crank-case-compression engine by design modifications to the transfer ports and manifolds. The method applies a basic CFD model of the steady-state flow across the cylinder block validated against experimental tests at the discharge flow bench. This model is used to approximate the actual scavenging process through a transient simulation of the cold flow across the cylinder inside which the piston is fixed at the bottom centre. A fast assessment of the charging efficiency is permitted by a transported passive scalar implemented in the model to easily estimate all the parameters needed for monitoring the effectiveness of the scavenging process at each crankangle. This practical design approach has been applied to the geometry of a Schnürle-type loop-scavenged 125cc single-cylinder engine compliant with the 2018 FIA homologation form for the KF2 karting competition category. The maximum increase of indicated mean effective pressure expected according to the comparison between the CFD simulations of the original and the modified design of the transfer ports is approximately equal to 4%. This result demonstrates that the CFD analyses are sensitive to the limited modifications commonly needed to tune two-stroke racing-engines and confirms that the suggested design approach can be profitably employed by engineers and technicians involved in the design of small two-stroke highspeed engines.
An appraisal of the application of open-cell foams in automotive SCR systems
Authors: Vespertini Andrea , Della Torre Augusto , Montenegro Gianluca , Onorati Angelo , Tronconi Enrico , Nova Isabella
Published: October 2020

This work aims to investigate the possibility to apply open-cell foams as catalytic substrates in SCR systems for Diesel engines, as a replacement of traditional honeycombs. In the literature, many studies compare the performance of foams and honeycombs as catalytic substrates, showing, in general, a better mass transfer behavior in foams, compensated on the other hand by a higher pressure drop. In this work, we consider the low-pressure injection of Ad-Blue and we evaluate the performance of the open-cell foam in enhancing the mixing and the evaporation of the spray. A Eulerian-Lagrangian CFD model has been adopted to simulate the spray evolution and its interaction with the microstructure of the open-cell foam. The model has been applied to evaluate the spray evaporation and the uniformity of the ammonia distribution in different sections of the substrate. Different operating conditions were tested comparing substrates with different geometrical properties. The results of this preliminary analysis can be regarded as promising, showing the capability of the foam to enhance the mixing of the spray and to achieve a uniform distribution of the ammonia over all the catalyst substrate.
Comparison Between Experimental and Simulated Knock Statistics Using an Advanced Fuel Surrogate Model
Authors: Cicci Francesco , Pessina Valentina , Iacovano Clara , Sparacino Simone , Barbato Alessio
Published: October 2020

The statistical tendency of a GDI spark-ignition engine to undergo knocking combustion as a consequence of spark timing variation is numerically investigated. In particular, attention is focused on the importance to match combustion-relevant and knock-relevant fuel properties to ensure consistency with the experimental evidence. An inhouse surrogate formulation methodology is used to emulate real gasoline properties, comparing fuel models of increasing complexity. Knock is investigated using a proprietary statistical knock model (GruMo Knock Model, GK-PDF). The model can infer a log-normal distribution of knock intensity within a RANS formalism, by means of transport equations for variances and turbulence-derived probability density functions (PDFs) for physical quantities. The calculated distributions are compared to measured statistical distributions. The proposed numerical/experimental comparison constitutes an advancement in synthetic chemistry integration into 3D-CFD combustion simulations.
Early Stage Calibration of a Formula SAE Engine 1-D Fluid Dynamic Model with Limited Experimental Data
Authors: Ammendola Francesco , Giardiello Giovanni , Gimelli Alfredo , Muccillo Massimiliano , Riccio Davide , Tufano Francesco , Zeppa Giuseppe
Published: October 2020

This work addresses the early stage calibration of a Formula SAE engine 1-D fluid dynamic model starting from limited experimental data. The availability of an engine model since the early stages of the development of a new Formula SAE vehicle allows to carry out preliminary analyses or ECU calibration. A few experimental tests have been executed at wide open throttle and variable engine speed. Then, a 1D thermo-fluid dynamic engine model has been developed starting from the geometry data of the engine. A vector optimization problem has been then solved to calibrate the engine model. In particular, the error minimization between numerical and experimental values of the torque in different engine operating conditions has been set as objective of the optimization process. Finally, starting from the results of the proposed calibration methodology, a decision-making criterion allowed the identification of a single optimal solution within the Pareto optimal front together with the related values for the set of calibration parameters. The results highlight how the proposed calibration procedure could be usefully adopted to set an early stage engine model which could be properly adopted to preliminarily detect the effects of geometric changes or control parameters variations on the main engine performance.
Real time estimation of emissions in a diesel vehicle with neural networks
Authors: Donateo Teresa , Filomena Riccardo
Published: October 2020

Several studies in literature have shown how real-world emissions strongly depend on driving condition, driving style, ambient temperature and humidity, etc. so that they are significantly different from the values measured on test benches over standard driving cycles. This concern, together with the so-called Diesel-gate, has caused the introduction in Europe of an innovative procedure for the registration of vehicle based on real driving emissions (RDE) measured with a portable emission measurement system (PEMS). PEMS devices are bulky and very expensive, therefore they cannot be extensively for an actual real time monitoring of emissions. To solve this problem, the present work proposes a Neural Network model based on the interpolation of the time-histories of driving conditions (speed, altitude, ambient temperature, humidity and pressure) and emissions measured on a diesel start-and-stop vehicle while performing a series of RDE tests. Two different approaches are proposed. The first one calculates the emissions on the basis of the vehicle motion (speed and altitude profile, ambient conditions). The second one models the engine block using as input the ambient conditions, the load and the rpm of the engine as derived from the OBD-II scanner. The output of both models are the flow rates and cumulated values of CO2 and NOx. Note that the inputs of the two models are signal that can easily obtained on-board without additional sensors.
Lumped parameter model and experimental tests on a pressure limiter for variable displacement pumps
Authors: Fresia Paola , Rundo Massimo
Published: October 2020

The paper presents the lumped parameter model of a pressure limiter for axial piston pumps developed in the Simcenter Amesim®environment. The control includes both the absolute and differential (load sensing) pressure limiter in a single body. The continuous position valve was tested experimentally alone on a test rig in order to estimate the discharge coefficients required for tuning the model. The tests were performed at imposed positions of the spool and the corresponding modulated pressure and control flow through the valve were measured. A contactless transducer was used for measuring with a very high accuracy the spool position. The influence of the bleed orifice on the pressure gain was also measured experimentally. It was found that the discharge coefficients have a significant influence on the hydraulic characteristic of the valve with also a consequence on the dynamic behavior of the entire displacement control.
A Numerical Analysis on a Solar Chimney with an Integrated Thermal Energy Storage with Phase Change Material in Metal Foam
Authors: Buonomo Bernardo , Capasso Lucia , Manca Oronzio , Menale Ferdinando , Nardini Sergio
Published: October 2020

In this paper, a two-dimensional numerical investigation on a prototypal solar chimney system integrated with an absorbing capacity wall in a south facade of a building is presented. The capacity wall is composed of a high absorbing plate and an assigned thickness of phase change material in metal foam. The chimney consists of a converging channel with one vertical absorbing wall and the glass plate inclined of 2°. The channel height inside the chimney is equal to 4.0 m, whereas the channel gap is at the inlet equal to 0.34 m and at the outlet it is 0.20 m. The thermal energy storage system is 4.0 m high. The numerical analysis was intended to evaluate the thermal and fluid dynamic behaviors of the solar chimney integrated with a latent thermal energy storage system. The investigation has shown that in all cases PCM has not fully melted during the day and the presence of aluminum foam inside the box attenuates the variation of temperatures during the day. The results show that the three different thickness of the thermal storage system present very similar fluid dynamic and thermal behaviors. For the analyzed configurations, the phase change material does not reach a total melting during the considered day.
Fluid dynamic-based Engineering design of a Full-Scale Device for the improvement of Extra Virgin Olive Oil Yield and Quality by means of Combined Acoustic Cavitation and Thermal Conditioning
Authors: Amirante Riccardo , Distaso Elia , Tamburrano Paolo , Corbo Filomena Faustina Rina , Calò Giuseppe , Clodoveo Maria Lisa
Published: October 2020

After some hesitations, the scientific community is jointly converging on the benefits due to the ultrasound treatment by means of mechanical effects generated by acoustic cavitation phenomena occurring into the olive oil paste proposed initially by Amirante and Clodoveo. In recent works, many authors have now confirmed that this promising emerging technology produces relevant beneficial effects if applied to the extraction process under well-controlled conditions. In the last years, the industrial applications of ultrasound (US) in the Extra-Virgin Olive Oil (EVOO) extraction process are changing the paradigm of the knowledge in this field of interest due to a great effort of the research activity. In the present work, the design of the device by means a Three-Dimensional (3D) Multiphase Computational Fluid Dynamic (CFD) analysis was performed, which describes the ultrasound effects in the olive paste, necessary to control the US waves propagation. Thus, fluid dynamic analysis allowed to predict the flow path in the ultrasound devices, to evaluate the flow parameters of the olive paste inside the SHE and the cavitation phenomenon, with the aim to find an optimal design, capable to ensure the best ultrasounds and mixing effects. Moreover, experimental results demonstrated that the machine can guarantee an actual simultaneous improvement of the olive oil extraction yield, as well as of the product quality. Finally, the results from sensory evaluations are summarized confirming the goodness of EVOO obtained by means of US.