bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Lung-Resident Macrophages Express and Are Targets of Thymic Stromal Lymphopoietin in the Tumor Microenvironment
Authors: Braile Mariantonia , Fiorelli Alfonso , Sorriento Daniela , Di Crescenzo Rosa Maria , Galdiero Maria Rosaria , Marone Gianni , Santini Mario , Varricchi Gilda , Loffredo Stefania
Published: August 2021

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine highly expressed by epithelial cells and several innate and adaptive immune cells. TSLP exerts its biological effects by binding to a heterodimeric complex composed of TSLP receptor (TSLPR) and IL-7Rα. In humans, there are two TSLP isoforms: the short form (sfTSLP), constitutively expressed, and the long form (lfTSLP), which is upregulated in inflammation. TSLP has been implicated in the induction and progression of several experimental and human cancers. Primary human lung macrophages (HLMs), monocyte-derived macrophages (MDMs), and peripheral blood monocytes consitutively expressed sfTSLP mRNA. Incubation of HLMs, MDMs, and monocytes with lipopolysaccharide (LPS) or IL-4, but not with IL-13, induced TSLP release from HLMs. LPS, but not IL-4 or IL-13, induced CXCL8 release from HLMs. LPS, IL-4 alone or in combination with IL-13, induced the expression of lfTSLP, but not of sfTSLP from HLMs. Preincubation of HLMs with IL-4, alone or in combination with IL-13, but not IL-13 alone, synergistically enhanced TSLP release from LPS-activated macrophages. By contrast, IL-4, alone or in combination with IL-13, inhibited LPS-induced CXCL8 release from HLMs. Immunoreactive TSLP was detected in lysates of HLMs, MDMs, and monocytes. Incubation of HLMs with TSLP induced the release of proinflammatory (TNF-α), angiogenic (VEGF-A, angiopoietin 2), and lymphangiogenic (VEGF-C) factors. TSLP, TSLPR, and IL-7Rα were expressed in intratumoral and peritumoral areas of human lung cancer. sfTSLP and lfTSLP mRNAs were differentially expressed in peritumoral and intratumoral lung cancer tissues. The TSLP system, expressed in HLMs, MDMs, and monocytes, could play a role in chronic inflammatory disorders including lung cancer.
Immunomodulation and Biomaterials: Key Players to Repair Volumetric Muscle Loss
Authors: Kiran Sonia , Dwivedi Pankaj , Kumar Vijay , Price Robert , Singh Udai
Published: August 2021

Volumetric muscle loss (VML) is defined as a condition in which a large volume of skeletal muscle is lost due to physical insult. VML often results in a heightened immune response, resulting in significant long-term functional impairment. Estimates indicate that ~250,000 fractures occur in the US alone that involve VML. Currently, there is no active treatment to fully recover or repair muscle loss in VML patients. The health economics burden due to VML is rapidly increasing around the world. Immunologists, developmental biologists, and muscle pathophysiologists are exploring both immune responses and biomaterials to meet this challenging situation. The inflammatory response in muscle injury involves a non-specific inflammatory response at the injured site that is coordination between the immune system, especially macrophages and muscle. The potential role of biomaterials in the regenerative process of skeletal muscle injury is currently an important topic. To this end, cell therapy holds great promise for the regeneration of damaged muscle following VML. However, the delivery of cells into the injured muscle site poses a major challenge as it might cause an adverse immune response or inflammation. To overcome this obstacle, in recent years various biomaterials with diverse physical and chemical nature have been developed and verified for the treatment of various muscle injuries. These biomaterials, with desired tunable physicochemical properties, can be used in combination with stem cells and growth factors to repair VML. In the current review, we focus on how various immune cells, in conjunction with biomaterials, can be used to promote muscle regeneration and, most importantly, suppress VML pathology.
Quantitative Proteomics Reveals Significant Differences between Mouse Brain Formations in Expression of Proteins Involved in Neuronal Plasticity during Aging
Authors: Drulis-Fajdasz Dominika , Gostomska-Pampuch Kinga , Duda Przemysław , Wiśniewski Jacek Roman , Rakus Dariusz
Published: August 2021

Aging is associated with a general decline in cognitive functions, which appears to be due to alterations in the amounts of proteins involved in the regulation of synaptic plasticity. Here, we present a quantitative analysis of proteins involved in neurotransmission in three brain regions, namely, the hippocampus, the cerebral cortex and the cerebellum, in mice aged 1 and 22 months, using the total protein approach technique. We demonstrate that although the titer of some proteins involved in neurotransmission and synaptic plasticity is affected by aging in a similar manner in all the studied brain formations, in fact, each of the formations represents its own mode of aging. Generally, the hippocampal and cortical proteomes are much more unstable during the lifetime than the cerebellar proteome. The data presented here provide a general picture of the effect of physiological aging on synaptic plasticity and might suggest potential drug targets for anti-aging therapies.
The Molecular Interplay between Human Coronaviruses and Autophagy
Authors: Shroff Ankit , Nazarko Taras Y.
Published: August 2021

Coronavirus disease 2019 (COVID-19), caused by a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has instantaneously emerged as a worldwide pandemic. However, humans encountered other coronaviruses in the past, and they caused a broad range of symptoms, from mild to life-threatening, depending on the virus and immunocompetence of the host. Most human coronaviruses interact with the proteins and/or double-membrane vesicles of autophagy, the membrane trafficking pathway that degrades and recycles the intracellular protein aggregates, organelles, and pathogens, including viruses. However, coronaviruses often neutralize and hijack this pathway to complete their life cycle. In this review, we discuss the interactions of human coronaviruses and autophagy, including recent data from SARS-CoV-2-related studies. Some of these interactions (for example, viral block of the autophagosome–lysosome fusion), while being conserved across multiple coronaviruses, are accomplished via different molecular mechanisms. Therefore, it is important to understand the molecular interplay between human coronaviruses and autophagy for developing efficient therapies against coronaviral diseases.
On the Radiolytic Stability of Potentiometric Sensors with Plasticized Polymeric Membranes
Authors: Savosina Julia , Agafonova-Moroz Marina , Khaydukova Maria , Legin Andrey , Babain Vasiliy , Tolstoy Peter , Kirsanov Dmitry
Published: August 2021

There is not much known on the stability of plasticized polymeric sensor membranes against ionizing radiation. While recent studies have indicated the applicability of potentiometric sensors with such membranes for quantification of actinides and lanthanides in spent nuclear fuel reprocessing solutions, the real industrial application of such sensors will require their stability in ionizing radiation fields. The present study explores this problem and evaluates the stability of potentiometric sensitivity towards lanthanides and actinides for a variety of plasticized polymeric membranes based on different neutral ligands. We demonstrate that most of the studied sensor compositions retain their sensitivity up to 50–100 kGy of the absorbed gamma radiation dose. The higher doses lead to the gradual loss of sensitivity due to the radiolysis of ligands and a polymer membrane matrix as confirmed by electrochemical impedance and nuclear magnetic resonance studies.
Numerical Modelling and Design of Aluminium Alloy Angles under Uniform Compression
Authors: Georgantzia Evangelia , Gkantou Michaela , Kamaris George S.
Published: August 2021

Research studies have been reported on aluminium alloy tubular and doubly symmetric open cross-sections, whilst studies on angle cross-sections remain limited. This paper presents a comprehensive numerical study on the response of aluminium alloy angle stub columns. Finite element models are developed following a series of modelling assumptions. Geometrically and materially nonlinear analyses with imperfections included are executed, and the obtained results are validated against experimental data available in the literature. Subsequently, a parametric study is carried out to investigate the local buckling behaviour of aluminium alloy angles. For this purpose, a broad range of cross-sectional aspect ratios, slenderness and two types of structural aluminium alloys are considered. Their effect on the cross-sectional behaviour and strength is discussed. Moreover, the numerically obtained ultimate strengths together with literature test data are utilised to assess the applicability of the European design standards, the American Aluminium Design Manual and the Continuous Strength Method to aluminium alloy angles. The suitability of the Direct Strength Method is also evaluated and a modified method is proposed to improve the accuracy of the strength predictions.
G-Doping-Based Metal-Semiconductor Junction
Authors: Tavkhelidze Avtandil , Jangidze Larissa , Taliashvili Zaza , Gorji Nima E.
Published: August 2021

Geometry-induced doping (G-doping) has been realized in semiconductors nanograting layers. G-doping-based p-p(v) junction has been fabricated and demonstrated with extremely low forward voltage and reduced reverse current. The formation mechanism of p-p(v) junction has been proposed. To obtain G-doping, the surfaces of p-type and p+-type silicon substrates were patterned with nanograting indents of depth d = 30 nm. The Ti/Ag contacts were deposited on top of G-doped layers to form metal-semiconductor junctions. The two-probe method has been used to record the I–V characteristics and the four-probe method has been deployed to exclude the contribution of metal-semiconductor interface. The collected data show a considerably lower reverse current in p-type substrates with nanograting pattern. In the case of p+-type substrate, nanograting reduced the reverse current dramatically (by 1–2 orders of magnitude). However, the forward currents are not affected in both substrates. We explained these unusual I–V characteristics with G-doping theory and p-p(v) junction formation mechanism. The decrease of reverse current is explained by the drop of carrier generation rate which resulted from reduced density of quantum states within the G-doped region. Analysis of energy-band diagrams suggested that the magnitude of reverse current reduction depends on the relationship between G-doping depth and depletion width.
Preparation and Characterization of (Al, Fe) Codoped ZnO Films Prepared by Sol–Gel
Authors: Wang Jiangang , Shen Wenjing , Zhang Xin , Li Jianhui , Ma Jing
Published: August 2021

In this research, Al-doped and (Al, Fe) codoped ZnO films were prepared on glass substrate by the sol–gel method. The surface morphology, structure, and optical property were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Ultraviolet-Visible-Near-infrared (UV-Vis-NIR) spectroscopy. The film surface morphologies all exhibited granular characteristics. With the Fe doping concentration increasing, the codoped films had smaller grain size and tended to be smoother. XRD analysis revealed that all films had a hexagonal wurtzite structure. The codoping can contribute to more Al and Fe ions entering the ZnO crystal structure, but result in the crystalline degree of the films decreasing. XPS results showed that the Al and Fe irons in the films exist in the form of trivalent. Moreover, the doped films had higher transmission, especially for codoped (Fe:Al = 3) film, but their absorption edge shifted to the short-wavelength direction.
Revisiting the Electronic Structures and Phonon Properties of Thermoelectric Antimonide-Tellurides: Spin–Orbit Coupling Induced Gap Opening in ZrSbTe and HfSbTe
Authors: Goumri-Said Souraya , Alrebdi Tahani A. , Deligoz Engin , Ozisik Haci , Kanoun Mohammed Benali
Published: August 2021

We report theoretical studies based on density functional theory within spin-orbit coupling to explore electronic structures, lattice dynamical properties of ZrSbTe and HfSbTe. With spin−orbit coupling included, our findings reveal that ZrSbTe and HfSbTe exhibit a semiconducting behavior with narrow indirect band gaps of 0.10 eV, and 0.15 eV, respectively. Besides, the lattice dynamical properties revealed that the explored materials based on antimonide−tellurides are dynamically stable. On the basis of electronic structures, the thermoelectric properties were computed using the Landauer-Buttiker formula by considering both electron and phonon contributions in the transport properties calculation. We employed Green’s-function method based on the Green-Kubo-Mori formula, where the thermoelectric properties such as the electrical conductivity σ and thermopower α were estimated in terms of the correlation functions. The present work could be viewed as a significant amendment of the electronic nature of ZrSbTe and HfSbTe that were reported to be metallic in literature.
Spin-Crossover in Iron(II) Complexes of N,N′-Disubstituted 2,6-Bis(Pyrazol-3-yl)Pyridines: An Effect of a Distal Substituent in the 2,6-Dibromophenyl Group
Authors: Nikovskiy Igor A. , Polezhaev Alexander V. , Novikov Valentin V. , Aleshin Dmitry Yu. , Aysin Rinat R. , Melnikova Elizaveta K. , Carrella Luca M. , Rentschler Eva , Nelyubina Yulia V.
Published: August 2021

A series of new bis(pyrazol-3-yl)pyridines (LR) N,N′-disubstituted by 4-functionalized 2,6-dibromophenyl groups have been synthesized to study the effect of a distal substituent on the spin-crossover (SCO) behaviour of the iron(II) complexes [Fe(LR)2](ClO4)2 by variable-temperature magnetometry, NMR spectroscopy, and X-ray diffraction. The SCO-assisting tendency of the substituents with different electronic and steric properties (i.e., the bromine atom and the methyl group) in the para-position of the 2,6-dibromophenyl group is discussed. Together with earlier reported SCO-active iron(II) complexes with N,N′-disubstituted bis(pyrazol-3-yl)pyridines, these new complexes open the way for this family of SCO compounds to emerge as an effective ‘tool’ in revealing structure–function relations, a prerequisite for successful molecular design of switchable materials for future breakthrough applications in sensing, switching, and memory devices.
An Integrated Perspective of Evolution and Development: From Genes to Function to Ear, Lateral Line and Electroreception
Authors: Fritzsch Bernd
Published: August 2021

Four sensory systems (vestibular, lateral line, electroreception, auditory) are unique and project exclusively to the brainstem of vertebrates. All sensory neurons depend on a common set of genes (Eya1, Sox2, Neurog1, Neurod1) that project to a dorsal nucleus and an intermediate nucleus, which differentiate into the vestibular ear, lateral line and electroreception in vertebrates. In tetrapods, a loss of two sensory systems (lateral line, electroreception) leads to the development of a unique ear and auditory system in amniotes. Lmx1a/b, Gdf7, Wnt1/3a, BMP4/7 and Atoh1 define the lateral line, electroreception and auditory nuclei. In contrast, vestibular nuclei depend on Neurog1/2, Ascl1, Ptf1a and Olig3, among others, to develop an independent origin of the vestibular nuclei. A common origin of hair cells depends on Eya1, Sox2 and Atoh1, which generate the mechanosensory cells. Several proteins define the polarity of hair cells in the ear and lateral line. A unique connection of stereocilia requires CDH23 and PCDH15 for connections and TMC1/2 proteins to perceive mechanosensory input. Electroreception has no polarity, and a different system is used to drive electroreceptors. All hair cells function by excitation via ribbons to activate neurons that innervate the distinct target areas. An integrated perspective is presented to understand the gain and loss of different sensory systems.
Assessing Spatial and Temporal Trends in a Mediterranean Fish Assemblage Structure
Authors: Marengo Michel , Iborra Laura , Leduc Michèle , Lejeune Pierre , Boissery Pierre , Gobert Sylvie
Published: August 2021

Coastal fishes are not only valuable elements of marine biodiversity, but they also play an important ecological role in the functioning of coastal ecosystems: food resource, transfer of nutrients, predators. Therefore, data on the compositions of fish assemblages are of great importance. The objectives of the present study were to (i) define the faunistic characteristics of a typical fish community on the Mediterranean coast; (ii) investigate spatiotemporal changes in fish assemblages. Based on a set of indices (Fast protocol) and a long-term data set (6 years, 612 visual counts, 154 h of diving), changes in coastal fish communities were analyzed. Our results indicated that there was a significant shift in fish community structure, with a general decline of the calculated indices. In our study, part of the observed variability in fish assemblage structure could be due to different factors as site location and sampled year. The changes in the fish assemblages associated with inter-annual fluctuations observed in this study also provide important insights into how fish communities may change under environmental and anthropogenic influences.
The Role of Fine Needle Aspiration Cytology in the Diagnosis of Gallbladder Cancer: A Systematic Review
Authors: Koimtzis Georgios D. , Chalklin Christopher G. , Carrington-Windo Eliot , Ramsden Mark , Stefanopoulos Leandros , Kosmidis Christoforos S.
Published: August 2021

Gallbladder cancer is the most common malignancy of the biliary tract. When diagnosed in an advanced stage it has a very poor prognosis. Therefore, early diagnosis and thorough assessment of a suspicious gallbladder polyp is essential to improve survival rate. The aim of this systematic review is to assess the role of fine needle aspiration cytology (FNAC) in the management of gallbladder cancer. For that purpose, a systematic review was carried out in the MEDLINE, EMBASE, Cochrane, Scopus and Google Scholar databases between 1 July 2004 and 22 April 2021. Six studies with 283 patients in total were included. Pooled sensitivity and specificity of FNAC were 0.85 and 0.94, respectively, while the area under the calculated summary receiver operating characteristic (SROC curve (AUC) was 0.98. No complications were reported. Based on the high diagnostic performance of FNAC in the assessment of gallbladder masses, we suggest that every suspicious mass should be evaluated further with FNAC to facilitate the most appropriate management.
Comparison of Supervised and Unsupervised Approaches for the Generation of Synthetic CT from Cone-Beam CT
Authors: Rossi Matteo , Cerveri Pietro
Published: August 2021

Due to major artifacts and uncalibrated Hounsfield units (HU), cone-beam computed tomography (CBCT) cannot be used readily for diagnostics and therapy planning purposes. This study addresses image-to-image translation by convolutional neural networks (CNNs) to convert CBCT to CT-like scans, comparing supervised to unsupervised training techniques, exploiting a pelvic CT/CBCT publicly available dataset. Interestingly, quantitative results were in favor of supervised against unsupervised approach showing improvements in the HU accuracy (62% vs. 50%), structural similarity index (2.5% vs. 1.1%) and peak signal-to-noise ratio (15% vs. 8%). Qualitative results conversely showcased higher anatomical artifacts in the synthetic CBCT generated by the supervised techniques. This was motivated by the higher sensitivity of the supervised training technique to the pixel-wise correspondence contained in the loss function. The unsupervised technique does not require correspondence and mitigates this drawback as it combines adversarial, cycle consistency, and identity loss functions. Overall, two main impacts qualify the paper: (a) the feasibility of CNN to generate accurate synthetic CT from CBCT images, which is fast and easy to use compared to traditional techniques applied in clinics; (b) the proposal of guidelines to drive the selection of the better training technique, which can be shifted to more general image-to-image translation.
Mors Gaudet Succurrere Vitae. The Role of Clinical Autopsy in Preventing Litigation Related to the Management of Liver and Digestive Disorders
Authors: D’Errico Stefano , Zanon Martina , Peruch Michela , Concato Monica , Padovano Martina , Santurro Alessandro , Scopetti Matteo , Fineschi Vittorio
Published: August 2021

Over the last 50 years, the number of clinical autopsies has decreased, but their role in assessing cause of death and clinical performance is still acknowledged. Few publications have studied their role in malpractice claim prevention. The paper aims to highlight the role of clinical autopsy in preventing errors and improve healthcare quality. A retrospective study was conducted on 28 clinical autopsies performed between 2015 and 2021 on patients dead unexpectedly after procedures for the diagnosis and treatment of digestive and hepatic diseases. After an accurate analysis of medical records and consultation with healthcare professionals, all cases were subjected to autopsy and histopathology. The data obtained were analyzed and shared with the risk-management team to identify pitfalls and preventive strategies. Post-mortem evaluations confirmed the clinical diagnosis only in six cases (21.4%). Discordances were observed in 10 cases (35.7%). In the remaining 12 cases (42.9%) the clinical diagnosis was labeled as “unknown” and post-mortem examinations made it possible to document the cause of death. Post-mortem examinations can concretely enrich hospital prevention systems and improve patient safety. The methodological approach outlined certainly demonstrates that, even in the risk-management field, “mors gaudet succurrere vitae” (“death delights in helping life”).
Dynamic Time Warping Algorithm in Modeling Systemic Risk in the European Insurance Sector
Authors: Denkowska Anna , Wanat Stanisław
Published: August 2021

We are looking for tools to identify, model, and measure systemic risk in the insurance sector. To this aim, we investigated the possibilities of using the Dynamic Time Warping (DTW) algorithm in two ways. The first way of using DTW is to assess the suitability of the Minimum Spanning Trees’ (MST) topological indicators, which were constructed based on the tail dependence coefficients determined by the copula-DCC-GARCH model in order to establish the links between insurance companies in the context of potential shock contagion. The second way consists of using the DTW algorithm to group institutions by the similarity of their contribution to systemic risk, as expressed by DeltaCoVaR, in the periods distinguished. For the crises and the normal states identified during the period 2005–2019 in Europe, we analyzed the similarity of the time series of the topological indicators of MST, constructed for 38 European insurance institutions. The results obtained confirm the effectiveness of MST topological indicators for systemic risk identification and the evaluation of indirect links between insurance institutions.
Design and Implementation of RF Front-End Module Based on 3D Heterogenous-Integrated Wafer-Level Packaging
Authors: Yu Faxin , Zhou Qi , Wang Zhiyu , Mo Jiongjiong , Chen Hua
Published: August 2021

In this paper, a three-dimensional heterogenous-integrated (3DHI) wafer-level packaging (WLP) process is proposed, and a radio frequency (RF) front-end module with two independent ultra-high frequency (UHF) receiving channels are designed and implemented, which covers 400 MHz–600 MHz and 2050 MHz–2200 MHz respectively for unmanned aerial vehicle (UAV) applications. The module is formed by wafer-to-wafer (W2W) bonding of two high-resistivity silicon (HR-Si) interposers with embedded bare dies and through silicon via (TSV) interconnections. Double-sided deep reactive ion etching (DRIE) and conformal electroplating process are introduced to realize the high-aspect-ratio TSV connection within 290 µm-thick cap interposer. Co-plane waveguide (CPW) transmission lines are fabricated as the process control monitor (PCM), the measured insertion loss of which is less than 0.18 dB/mm at 35 GHz. The designed RF front-end module is fabricated and measured. The measured return loss and gain of each RF channel is better than 13 dB and 21 dB, and the noise figure is less than 1.5 dB. In order to evaluate the capability of the 3DHI process for multi-layer interposers, the module is re-designed and fabricated with four stacked high-resistivity silicon interposers. After W2W bonding of two pairs of interposers and wafer slicing, chip-to chip (C2C) bonding is applied to form a four-layer module with operable temperature gradient.
Ferroelectric Induced UV Light-Responsive Memory Devices with Low Dark Current
Authors: Lee Hanleem , Chun Young Tea
Published: August 2021

We developed solution-processed hybrid photodetectors with a poly (9-vinylcarbazole)/zinc oxide nanoparticle photoactive layer and a poly (vinylidene fluoride-co-trifluoroethylene) ferroelectric copolymer buffer layer on flexible plastic substrates. The presence of a ferroelectric-poling interface layer significantly enhanced the charge transfer and responsivity of the photodetectors under ultraviolet (UV, 365 nm) light exposure. The responsivity of the device reached 250 mA/W at a reverse bias of 5 V and incident light intensity of 27.5 μW/cm2. This responsivity was four times higher than that of a device without the ferroelectric copolymer layer (64 mA/W) under the same conditions. The response time of the device to incident UV light also improved from 322 to 34 ms with the addition of the ferroelectric copolymer layer. In addition, the flexible device exhibited a stable performance in an air environment up to a maximum strain of 0.3 under bending stress. Finally, a UV-light-responsive memory device was successfully fabricated by using the developed hybrid photodetector and liquid crystals. This device showed a colour change from white to black upon UV illumination, and the on-state of the device was maintained for 30 s without light exposure owing to the polarization of poly (vinylidene fluoride-co-trifluoroethylene).
Impact of Process-Induced Variations on Negative Capacitance Junctionless Nanowire FET
Authors: Choi Yejoo , Lee Jinwoong , Lim Jaehyuk , Moon Seungjun , Shin Changhwan
Published: August 2021

In this study, the impact of the negative capacitance (NC) effect on process-induced variations, such as work function variation (WFV), random dopant fluctuation (RDF), and line edge roughness (LER), was investigated and compared to those of the baseline junctionless nanowire FET (JL-NWFET) in both linear (Vds = 0.05 V) and saturation (Vds = 0.5 V) modes. Sentaurus TCAD and MATLAB were used for the simulation of the baseline JL-NWFET and negative capacitance JL-NWFET (NC-JL-NWFET). Owing to the NC effect, the NC-JL-NWFET showed less variation in terms of device performance, such as σ[Vt], σ[SS], σ[Ion/Ioff], σ[Vt]/µ[Vt], σ[SS]/µ[SS], and σ[Ion/Ioff]/µ[Ion/Ioff], and enhanced device performance, which implies that the NC effect can successfully control the variation-induced degradation.
A Low-Power CMOS Bandgap Voltage Reference for Supply Voltages Down to 0.5 V
Authors: Ria Andrea , Catania Alessandro , Bruschi Paolo , Piotto Massimo
Published: August 2021

A voltage reference is strictly required for sensor interfaces that need to perform nonratiometric data acquisition. In this work, a voltage reference capable of working with supply voltages down to 0.5 V is presented. The voltage reference was based on a classic CMOS bandgap core, properly modified to be compatible with low-threshold or zero-threshold MOSFETs. The advantages of the proposed circuit are illustrated with theoretical analysis and supported by numerical simulations. The core was combined with a recently proposed switched capacitor, inverter-like integrator implementing offset cancellation and low-frequency noise reduction techniques. Experimental results performed on a prototype designed and fabricated using a commercial 0.18 μm CMOS process are presented. The prototype produces a reference voltage of 220 mV with a temperature sensitivity of 45 ppm/°C across a 10–50 °C temperature range. The proposed voltage reference can be used to source currents up to 100 μA with a quiescent current consumption of only 630 nA.
Toward a Scalable Fabrication of Perovskite Solar Cells under Fully Ambient Air Atmosphere: From Spin-Coating to Inkjet-Printing of Perovskite Absorbent Layer
Authors: Karavioti Aggeliki , Chalkias Dimitris A. , Katsagounos Giannis , Mourtzikou Argyroula , Kalarakis Alexandros N. , Stathatos Elias
Published: August 2021

Up until now, the vast majority of perovskite solar cells (PSCs) have relied on the spin-coating of perovskite precursor solution under inert fully controlled conditions, with the performance of solar cells that are developed by alternative techniques and under an ambient atmosphere to lag far behind. This impedes the technology transfer from the laboratory to industrial large-scale production; thus, the investigation of new scalable techniques should be thoroughly considered. The present work constitutes one of the few investigations on the application of inkjet-printing as an advanced alternative technique to the conventional spin-coating technique used for the fabrication of fully ambient air-processed perovskite absorbent layers for carbon-based hole transport layer-free PSCs. A systematic study of the characteristics of the perovskite material and solar cells indicated that the coffee-ring effect combined with poor ink penetration into the mesoporous network of the anode semiconductor were the main reasons for obtaining poor perovskite structure morphology and lower PSC performance by inkjet-printing, which arises from a lower internal quantum efficiency and an increased charge transfer and recombination rate. On the other hand, the crystallinity and optical characteristics of the materials obtained by the compared techniques did not differ considerably, while small differences were observed in the hysteretic behavior and long-term stability of the solar cells.
Recommendations for Running a Tandem of Adsorption Chillers Connected in Series and Powered by Low-Temperature Heat from District Heating Network
Authors: Nalepa Bartlomiej , Halon Tomasz
Published: August 2021

In this paper, we investigate implications of running a cooling system of two silicagel/water adsorption chillers powered by a district heating network. The devices are connected in series, i.e., the heating water output from the primary chiller is directed to the secondary one. In consequence, the secondary device must deal with an even lower driving temperature and with temperature fluctuations caused by the primary device. We have evaluated three factors that influence the operation of those coupled devices: synchronization of their operating cycles, selection of their cycle time allocations (CTAs), and changing the heating water mass flow rate. Numerical analyses indicate that the performance of the secondary chiller drops significantly if the coupled devices that use the same CTA run asynchronously. The decrease is largest if the shift between the operating cycles is x=0.375 and x=0.875. We found that it is possible to reduce the negative influence of the asynchronous operation by implementing different CTA in each chiller. The best performance is achieved if the primary chiller uses an adsorption time to desorption time ratio f=1.0 and the secondary chiller uses f = 0.6–0.7.
Load Frequency Active Disturbance Rejection Control for Multi-Source Power System Based on Soft Actor-Critic
Authors: Zheng Yuemin , Tao Jin , Sun Hao , Sun Qinglin , Chen Zengqiang , Dehmer Matthias , Zhou Quan
Published: August 2021

To ensure the safe operation of an interconnected power system, it is necessary to maintain the stability of the frequency and the tie-line exchanged power. This is one of the hottest issues in the power system field and is usually called load frequency control. To overcome the influences of load disturbances on multi-source power systems containing thermal power plants, hydropower plants, and gas turbine plants, we design a linear active disturbance rejection control (LADRC) based on the tie-line bias control mode. For LADRC, the parameter selection of the controller directly affects the response performance of the entire system, and it is usually not feasible to manually adjust parameters. Therefore, to obtain the optimal controller parameters, we use the Soft Actor-Critic algorithm in reinforcement learning to obtain the controller parameters in real time, and we design the reward function according to the needs of the power system. We carry out simulation experiments to verify the effectiveness of the proposed method. Compared with the results of other proportional–integral–derivative control techniques using optimization algorithms and LADRC with constant parameters, the proposed method shows significant advantages in terms of overshoot, undershoot, and settling time. In addition, by adding different disturbances to different areas of the multi-source power system, we demonstrate the robustness of the proposed control strategy.
Performance and Durability of the Zr-Doped CaO Sorbent under Cyclic Carbonation–Decarbonation at Different Operating Parameters
Authors: Rodaev Vyacheslav V. , Razlivalova Svetlana S.
Published: August 2021

The effect of cyclic carbonation–decarbonation operating parameters on Zr-doped CaO sorbent CO2 uptake capacity evolution is examined. It is revealed that the capacity steady state value increases with the decrease in the carbonation temperature, CO2 concentration in the gas flow upon carbonation and with the increase in the heating rate from the carbonation to the decarbonation stages. The rise in decarbonation temperature leads to a dramatic decrease in the sorbent performance. It is found that if carbonation occurs at 630 °C in the gas flow containing 15 vol.% CO2 and decarbonation is carried out at 742 °C, the sorbent shows the highest values of the initial and steady state CO2 uptake capacity, namely, 10.7 mmol/g and 9.4 mmol/g, respectively.
Addressing the Effect of Social Acceptance on the Distribution of Wind Energy Plants and the Transmission Grid in Germany
Authors: Flachsbarth Franziska , Wingenbach Marion , Koch Matthias
Published: August 2021

Social acceptance is increasingly becoming a limiting factor in implementing the energy transition in Germany. From today’s perspective, the expansion of wind energy and future transmission grids is only somewhat a technical or economic challenge rather than a social one. Since political decisions on the energy system transformation are often derived from findings of energy system modeling, it seems necessary to increasingly integrate the effects of socio-ecological aspects, such as acceptance issues in energy models. In this paper, an approach is introduced to address effects of social acceptance in energy system models by comparing the influence of different distribution scenarios of wind energy in Germany on the expansion need for future transmission lines. The results show that a socio-ecologic distribution of onshore wind installations according to a balanced burden of the German society does not reduce the grid expansion need significantly compared to an economic siting. An actual reduction of planned transmission grids could just be achieved by a more decentral scenario, including decentral market design. The sensitivity of regionalization is an opportunity to consider local acceptance issues within energy system models and should move more into focus inside the procedure of the current grid development process in Germany.
Longwall Top-Coal Caving Mechanism and Cavability Optimization with Hydraulic Fracturing in Thick Coal Seam: A Case Study
Authors: Wang Zhaohui , Tang Yuesong , Gong Hao
Published: August 2021

Longwall top-coal caving mechanisms and cavability optimization with hydraulic fracturing are analysed in this study. Based on the geological and geotechnical conditions of the Dongzhouyao coal mine, it is revealed that top-coal failure mechanisms are dominated by both compressive and tensile stresses. Ahead of the face line, shear failure initiates at the lower level of the top-coal and propagates to the upper level. Compressive stress-induced damage leads to obvious deterioration in tensile strength, causing the onset of tensile failure in the top-coal behind the face line. Accumulated plastic strain (APS) is selected as a top-coal cavability indicator. The cavability degrades gradually at the higher elevation of the top-coal while it is greatly strengthened as the top-coal approaches closer to the face line. In a thick coal seam without hydraulic fractures, the maximum APS occurs at the middle section of the face length in the Longwall top-coal caving (LTCC) panel. After hydraulic fracturing, top-coal cavability is significantly enhanced. But the spatial distribution of the APS transitions from uniform to non-uniform type due to the existence of hydraulic fractures, causing great variety in the cavability along the panel width. With increasing fracture intensity and fracture size, the failure zone expands significantly ahead of the longwall face, which means the cavability becomes increasingly favourable.
Passivation Strategies through Surface Reconstruction toward Highly Efficient and Stable Perovskite Solar Cells on n-i-p Architecture
Authors: Suo Jiajia , Yang Bowen , Hagfeldt Anders
Published: August 2021

Perovskite solar cells have achieved remarkable enhancement in their performance in recent years. However, to get an entrance to the photovoltaic market, great effort is still necessary to further improve their efficiency as well as their long-term stability under various conditions. Among various types of approaches (including compositional engineering, dopant engineering, self-assembled monolayers (SAMs), et al.), interfacial engineering through passivation treatment has been considered as one of the most effective strategies to reduce the non-radiative recombination within the PSCs. Thus, this short review summaries recent efforts on chemical interfacial passivation strategies from a different perspective owing to their common phenomena of reconstructing the perovskite surface via the formation of three-dimensional perovskite, low-dimensional perovskite and synergistic effect provided by a mixed-salt passivation system, respectively.
Exergy and Energy Analyses of Microwave Dryer for Cantaloupe Slice and Prediction of Thermodynamic Parameters Using ANN and ANFIS Algorithms
Authors: Zadhossein Safoura , Abbaspour-Gilandeh Yousef , Kaveh Mohammad , Szymanek Mariusz , Khalife Esmail , D. Samuel Olusegun , Amiri Milad , Dziwulski Jacek
Published: August 2021

The study targeted towards drying of cantaloupe slices with various thicknesses in a microwave dryer. The experiments were carried out at three microwave powers of 180, 360, and 540 W and three thicknesses of 2, 4, and 6 mm for cantaloupe drying, and the weight variations were determined. Artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS) were exploited to investigate energy and exergy indices of cantaloupe drying using various afore-mentioned input parameters. The results indicated that a rise in microwave power and a decline in sample thickness can significantly decrease the specific energy consumption (SEC), energy loss, exergy loss, and improvement potential (probability level of 5%). The mean SEC, energy efficiency, energy loss, thermal efficiency, dryer efficiency, exergy efficiency, exergy loss, improvement potential, and sustainability index ranged in 10.48–25.92 MJ/kg water, 16.11–47.24%, 2.65–11.24 MJ/kg water, 7.02–36.46%, 12.36–42.70%, 11.25–38.89%, 3–12.2 MJ/kg water, 1.88–10.83 MJ/kg water, and 1.12–1.63, respectively. Based on the results, the use of higher microwave powers for drying thinner samples can improve the thermodynamic performance of the process. The ANFIS model offers a more accurate forecast of energy and exergy indices of cantaloupe drying compare to ANN model.
Intelligent Dynamic Pricing Scheme for Demand Response in Brazil Considering the Integration of Renewable Energy Sources
Authors: Vilar Diego B. , Affonso Carolina M.
Published: August 2021

This paper proposes a novel dynamic pricing scheme for demand response with individualized tariffs by consumption profile, aiming to benefit both customers and utility. The proposed method is based on the genetic algorithm, and a novel operator called mutagenic agent is proposed to improve algorithm performance. The demand response model is set by using price elasticity theory, and simulations are conducted based on elasticity, demand, and photovoltaic generation data from Brazil. Results are evaluated considering the integration effects of renewable energy sources and compared with other two pricing strategies currently adopted by Brazilian utilities: flat tariff and time-of-use tariff. Simulation results show the proposed dynamic tariff brings benefits to both utilities and consumers. It reduces the peak load and average cost of electricity and increases utility profit and load factor without the undesirable rebound effect.
Sequential Capacitor-Based Closed-Loop Precharge Control during the Single-Phase MMC Start-Up Process
Authors: Ghoneim Walid Ahmed Maher , Aziz Ahmed Alaa
Published: August 2021

Modularity, flexible scalability, and high efficiency are some of the aspects that have paved the way toward the modular multilevel converter (MMC) being regarded as one of the most encouraging converter technologies for medium-/high-power applications; however, the precharging process of all the distributed submodules’ capacitors during the MMC’s start-up is considered to be a very challenging technical problem, which has been the center of attention since the emergence of the MMC back in 2002. In this paper, a new start-up method based on the sequential capacitors’ charging method is introduced for precharging the single-phase MMC from the DC grid while drastically reducing the charging (start-up) time. A detailed design algorithm for the proposed start-up method is presented. The findings of the simulation of the proposed method are provided to illustrate the capability of the suggested method.
Energy and Local Safety: How the Administration Limits Energy Security
Authors: Dobrowolski Zbysław
Published: August 2021

Energy safety is multifaceted and is not limited only to nuclear plants. The research on local energy safety is not considerable. This article creates new ground by analysing the Polish local energy safety system in the cause–effect context. Consistent with an abductive approach, this paper’s insights have emerged iteratively based on the theory reviewed and the empirical case. The research aimed to determine whether the local administration negatively affected energy security and proposed preventive measures increased limited energy security. The findings show that flawed local government operations reduce local energy safety. Moreover, the State authorities did not recognise the weaknesses of the local energy safety system properly. The findings make two main contributions: first, they contribute to developing energy safety theory; and second, this article contributes to a further contextual diagnosis of the comprehensive energy system and can, in turn, be relevant for its further studies in worldwide context.
An Algorithm for Calculation and Extraction of the Grid Voltage Component
Authors: Gwóźdź Michał , Ciepliński Łukasz
Published: August 2021

Calculating the values of the parameters of distorted periodic signals in real-time is important for the control of many processes. In particular, this information is necessary for the proper operation of power electronics devices that cooperate with the power grid. In such cases, it is necessary to determine the phase, frequency, and amplitude of the fundamental component of the voltage in the power grid node. Also, in many cases, the control process needs a signal which is synchronised with the power grid voltage. Both processes should be realised in real-time. A number of solutions to the problem of calculating the values of the voltage parameters have been described in the literature. However, these methods generally introduce significant time delays and have several restrictions regarding the variability in the values of these parameters. They also often require the significant computational power of a unit that performs the task of identification. The algorithm presented in this work is based on the properties of a pair of orthogonal signals, generated by a two-dimensional finite impulse response filter, which has a certain transfer function resulting from the needs of the algorithm, what is the innovation of the algorithm. These signals are then used in the program module, which both, calculates, in the time domain, the instantaneous values of the frequency and the amplitude of the fundamental component of the power grid voltage, and generates a signal, being in-phase with this component. The presented algorithm is fast, accurate, and relatively simple; therefore, it does not require a high computational power processor. This algorithm was experimentally verified by implementation in microcomputer-based units, which were then applied in the control systems of the power electronic devices, as well as in analysers of the energy quality.
Gas Engine-Driven Heat Pumps for Small-Scale Applications: State-of-the-Art and Future Perspectives
Authors: Roselli Carlo , Marrasso Elisa , Sasso Maurizio
Published: August 2021

Gas engine-driven heat pumps are an interesting option to satisfy space heating and cooling demands aiming at energy saving, environmental impact and operating costs’ reduction. This work presents (i) a comprehensive review updated on gas engine-driven heat pumps research activities, (ii) the investigation of the central role of this technology in the air conditioning sector and (iii) the future perspectives regarding gas engine heat pumps’ diffusion in the context of the energy sector decarbonisation. The outcomes highlight that gas engine heat pumps could have better environmental performance compared to electric heat pumps both in heating and cooling operations. Moreover, they could play a pivotal role in the fight against climate change and energy security since they can guarantee an energy mix differentiation moving from electricity to natural gas and renewable gases’ usage. Indeed, by 2030, a lower-carbon gas grid could be supported by renewable gases. A further investigation has concerned diffusion of gas heat pumps activated from biofuels produced by local biomass in an energy community scenario based on a low-temperature energy district network. A novel biomass-based GEHP interacting with a low-temperature district heating network is proposed here. This system could save more than 30% of primary energy compared to biomass-fuelled boilers.