bluuebunny/crossref_metadata_2025 huggingface dataset:
Clemastine improves electrophysiologic and histomorphometric changes through promoting myelin repair in a murine model of compression neuropathy
Authors: Lee Jung Il , Park Jong Woong , Lee Kyung Jun , Lee Duk Hee
Published: October 2021

Compression neuropathies are common and debilitating conditions that result in variable functional recovery after surgical decompression. Recent drug repurposing studies have verified that clemastine promotes functional recovery through enhancement of myelin repair in demyelinating disease. We investigated the utility of clemastine as a treatment for compression neuropathy using a validated murine model of compression neuropathy encircling the compression tube around the sciatic nerve. Mice received PBS or clemastine solution for 6 weeks of compression phase. Mice taken surgical decompression received PBS or clemastine solution for 2 weeks of decompression phase. Electrodiagnostic, histomorphometric, and Western immunoblotting analyses were performed to verify the effects of clemastine. During the compression phase, mice treated with clemastine had significantly decreased latency and increased amplitude compared to untreated mice that received PBS. Histomorphometric analyses revealed that mice treated with clemastine had significantly higher proportions of myelinated axons, thicker myelin, and a lower G-ratio. The expression levels of myelin proteins, including myelin protein zero and myelin associated glycoprotein, were higher in mice treated with clemastine. However, the electrophysiologic and histomorphometric improvements were observed regardless of clemastine treatment in mice taken surgical decompression. Mice treated with clemastine during compression of the sciatic nerve demonstrated that clemastine treatment attenuated electrophysiologic and histomorphometric changes caused by compression through promoting myelin repair.
Cumulative DNA damage by repeated low-dose cisplatin injection promotes the transition of acute to chronic kidney injury in mice
Authors: Yamashita Noriyuki , Nakai Kunihiro , Nakata Tomohiro , Nakamura Itaru , Kirita Yuhei , Matoba Satoaki , Humphreys Benjamin D. , Tamagaki Keiichi , Kusaba Tetsuro
Published: October 2021

Cisplatin is a commonly used anticancer drug, but nephrotoxicity is a dose-limiting adverse effect. Recent experimental and clinical observations have demonstrated that multiple injections of cisplatin induce the transition to chronic kidney disease; however, the underlying mechanisms remain unclear. We found that multiple injections of higher doses of cisplatin in a shorter interval affected the severity of kidney injury, causing kidney fibrosis to develop at a later time point. An additional injection of cisplatin during the recovery period after a prior injury, when proximal tubule epithelia are actively proliferating, induced substantial tubular injury by inducing more severe DNA damage than that induced by a single injection. Lineage tracing analysis of proximal tubular epithelia demonstrated that the tubular epithelia that underwent multiple rounds of cell division after multiple injections of cisplatin existed at the chronic phase, and these populations often expressed vcam1 + , suggesting the induction of proinflammatory failed-repair tubular epithelia. Our study revealed that as cisplatin exerts cytotoxic effects on actively proliferating cells, additional cisplatin injections before the completion of tubular repair exacerbates kidney injury through cumulative DNA damage. Appropriate both the setting of dosage and dosing intervals, with careful monitoring, are essential to prevent nephrotoxicity of repeated cisplatin treatment in cancer patients.
Paediatric Trauma Score as a non-imaging tool for predicting intracranial haemorrhage in patients with traumatic brain injury
Authors: Kim Heoung Jin , Eun Sohyun , Yoon Seo Hee , Kim Moon Kyu , Chung Hyun Soo , Koo Chungmo
Published: October 2021

To identify a useful non-imaging tool to screen paediatric patients with traumatic brain injury for intracranial haemorrhage (ICH). We retrospectively analysed patients aged < 15 years who visited the emergency department with head trauma between January 2015 and September 2020. We divided patients into two groups (ICH and non-ICH) and compared their demographic and clinical factors. Among 85 patients, 21 and 64 were in the ICH and non-ICH groups, respectively. Age (p = 0.002), Pediatric trauma score (PTS; p < 0.001), seizure (p = 0.042), and fracture (p < 0.001) differed significantly between the two groups. Factors differing significantly between the groups were as follows: age (odds ratio, 0.84, p = 0.004), seizure (4.83, p = 0.013), PTS (0.15, p < 0.001), and fracture (69.3, p < 0.001). Factors with meaningful cut-off values were age (cut-off [sensitivity, specificity], 6.5 [0.688, 0.714], p = 0.003) and PTS [10.5 (0.906, 0.81), p < 0.001]. Based on the previously known value for critical injury (≤ 8 points) and the cut-off value of the PTS identified in this study (≤ 10 points), we divided patients into low-risk, medium-risk, and high-risk groups; their probabilities of ICH (95% confidence intervals) were 0.16–12.74%, 35.86–89.14%, and 100%, respectively. PTS was the only factor that differed significantly between mild and severe ICH cases (p = 0.012). PTS is a useful screening tool with a high predictability for ICH and can help reduce radiation exposure when used to screen patient groups before performing imaging studies.
Non fourier heat transfer enhancement in power law fluid with mono and hybrid nanoparticles
Authors: Sadiq M. Adil
Published: October 2021

Several polymers like ethylene glycol exhibit non-Newtonian rheological behavior. Ethylene glycol is a world-widely used engine coolant and therefore, investigation of thermal enhancement by dispersing mono and hybrid nanoparticles in ethylene glycol is worthful. Since ethylene glycol has shear rate-dependent viscosity and it obeys the power-law rheological model. Therefore, based on these facts, the power-law rheological model with thermophysical properties is augmented with basic law of heat transfer in fluid for the modeling of the considered physical situation. $$Mo{S}_{2}$$

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o

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2

are taken as mono-nanoparticles where $$Mo{S}_{2}$$

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o

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2

and $$Si{O}_{2}$$

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i

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2

are taken as hybrid nanoparticles. Comparative study for the enhancement of thermal performance of MoS2 ethylene glycol and $$Mo{S}_{2}$$

M
o

S
2

−$$Si{O}_{2}$$

S
i

O
2

– ethylene glycol is done. For energy conservation, non-Fourier’s law of Cattaneo–Christov is used. The power-law fluid becomes more heat generative due to the dispersion of $$Mo{S}_{2}$$

M
o

S
2

and $$Si{O}_{2}$$

S
i

O
2

. However, $$Mo{S}_{2}$$

M
o

S
2

−power-law fluid is less heat generative relative to $$Mo{S}_{2}$$

M
o

S
2

− $$Si{O}_{2}$$

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i

O
2

-nanofluid. Thermal relaxation time is found proportional to the ability of the fluid to restore its thermal equilibrium.
Water deficit modifies C:N:P stoichiometry affecting sugarcane and energy cane yield and its relationships with silicon supply
Authors: de Oliveira Filho Antonio Santana Batista , de Mello Prado Renato , Teixeira Gelza Carliane Marques , de Cássia Piccolo Marisa , Rocha Antonio Márcio Souza
Published: October 2021

Climate change has increased the occurrence of water deficit in regions where sugarcane and energy cane are cultivated, jeopardizing dry matter production of stems. It was hypothesized that the reasons behind this fact relate to C:N:P stoichiometric modifications in these species that impair the conversion rates of accumulated nutrients in the stems, which could be attenuated by supplying silicon (Si) to the crops. Thus, the aims of this study were to evaluate the effects of water deficit in sugarcane and energy cane ratoons in the presence and absence of Si, in the C:N:P stoichiometry of stems, in the use efficiency of these nutrients and in the accumulation of dry matter in stems. Two experiments were carried out, using sugarcane (Saccharum officinarum) and energy cane (S. spontaneum), cultivated in pots filled with a Typic Quartzipisamment. The treatments for both experiments were arranged in a factorial scheme 2 × 2, without (70% of the soil’s water retention capacity) and with (30% of the capacity) water deficit, without and with the application of Si via fertirrigation, associated with foliar pulverization, both at a concentration of 2.5 mmol L−1, arranged in randomized blocks. The reduction in dry matter production of stems in both species caused by water deficit was due to modifications of the C, N and P stoichiometric homeostasis, but the benefit of Si in these plants when increasing dry matter production was not a reflection of the change in homeostasis, thus it may be involved in other mechanisms that remain unknown and should be further studied.
TBC1D10C is a cytoskeletal functional linker that modulates cell spreading and phagocytosis in macrophages
Authors: Villagomez Fabian R. , Diaz-Valencia Juan D. , Ovalle-García Erasmo , Antillón Armando , Ortega-Blake Iván , Romero-Ramírez Héctor , Cerna-Cortes Jorge F. , Rosales-Reyes Roberto , Santos-Argumedo Leopoldo , Patiño-López Genaro
Published: October 2021

Cell spreading and phagocytosis are notably regulated by small GTPases and GAP proteins. TBC1D10C is a dual inhibitory protein with GAP activity. In immune cells, TBC1D10C is one of the elements regulating lymphocyte activation. However, its specific role in macrophages remains unknown. Here, we show that TBC1D10C engages in functions dependent on the cytoskeleton and plasma membrane reorganization. Using ex vivo and in vitro assays, we found that elimination and overexpression of TBC1D10C modified the cytoskeletal architecture of macrophages by decreasing and increasing the spreading ability of these cells, respectively. In addition, TBC1D10C overexpression contributed to higher phagocytic activity against Burkholderia cenocepacia and to increased cell membrane tension. Furthermore, by performing in vitro and in silico analyses, we identified 27 TBC1D10C-interacting proteins, some of which were functionally classified as protein complexes involved in cytoskeletal dynamics. Interestingly, we identified one unreported TBC1D10C-intrinsically disordered region (IDR) with biological potential at the cytoskeleton level. Our results demonstrate that TBC1D10C shapes macrophage activity by inducing reorganization of the cytoskeleton-plasma membrane in cell spreading and phagocytosis. We anticipate our results will be the basis for further studies focused on TBC1D10C. For example, the specific molecular mechanism in Burkholderia cenocepacia phagocytosis and functional analysis of TBC1D10C-IDR are needed to further understand its role in health and disease.
Altered gene expression in slc4a11−/− mouse cornea highlights SLC4A11 roles
Authors: Alvarez Bernardo V. , Piché Marilyse , Aizouki Carolin , Rahman Fariha , Derry Jonathan M. J. , Brunette Isabelle , Casey Joseph R.
Published: October 2021

SLC4A11 is a H+/NH3/water transport protein, of corneal endothelial cells. SLC4A11 mutations cause congenital hereditary endothelial dystrophy and some cases of Fuchs endothelial corneal dystrophy. To probe SLC4A11’s roles, we compared gene expression in RNA from corneas of 17-week-old slc4a11−/− (n = 3) and slc4a11+/+ mice (n = 3) and subjected to RNA sequencing. mRNA levels for a subset of genes were also assessed by quantitative real-time reverse transcription PCR (qRT RT-PCR). Cornea expressed 13,173 genes, which were rank-ordered for their abundance. In slc4a11−/− corneas, 100 genes had significantly altered expression. Abundant slc14a1 expression, encoding the urea transporter UT-A, suggests a significant role in the cornea. The set of genes with altered expression was subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, revealing that alterations clustered into extracellular region, cytoskeleton, cell adhesion and plasma membrane functions. Gene expression changes further clustered into classes (with decreasing numbers of genes): cell fate and development, extracellular matrix and cell adhesion, cytoskeleton, ion homeostasis and energy metabolism. Together these gene changes confirm earlier suggestions of a role of SLC4A11 in ion homeostasis, energy metabolism, cell adhesion, and reveal an unrecognized SLC4A11 role in cytoskeletal organization.
Microstructure and properties evolution of Mg–2Y–0.6Nd–0.6Zr alloy rolled at room and liquid nitrogen temperature
Authors: Tan Yun , Li Wei , Li Aiwen , Shi Xiaofang
Published: October 2021

The microstructure evolution, texture, mechanical behavior and twin deformation of the ECAPed Mg–2Y–0.6Nd–0.6Zr alloy at room and liquid nitrogen temperature were investigated by rolling samples. The ECAP processed material appeared the texture of 45° to the extrusion direction and its yield strength reached 93.6 MPa. The results showed that cryorolling encourages twinning in Mg–2Y–0.6Nd–0.6Zr alloy, enhancing the tensile strength and texture. Activation of {10–12} twinning during rolling was found to be more pronounced in the cryorolled samples than in the cold rolled samples owing to a lower temperature. As a result, the cryorolled samples had more twins than and cold rolled ones, the proportion of twin areas of room temperature rolling and ultra-low temperature rolling were: 2.45% and 4.23%.
Quantitative analysis of size and regional distribution of corpora amylacea in the hippocampal formation of obstructive sleep apnoea patients
Authors: Xu Cuicui , Owen Jessica E. , Gislason Thorarinn , Benediktsdottir Bryndis , Robinson Stephen R.
Published: October 2021

Corpora amylacea (CoA) are spherical aggregates of glucose polymers and proteins within the periventricular, perivascular and subpial regions of the cerebral cortex and the hippocampal cornu ammonis (CA) subfields. The present study quantified the distribution of CoA in autopsied hippocampi of patients with obstructive sleep apnoea (OSA) using ethanolamine-induced fluorescence. CoA were observed in 29 of 30 patients (96.7%). They were most abundant in periventricular regions (wall of lateral ventricle, alveus, fimbria and CA4), rarely found in the CA3 and CA1, and undetectable in the CA2 or subiculum. A spatiotemporal sequence of CoA deposition was postulated, beginning in the fimbria and progressively spreading around the subpial layer until they extended medially to the wall of the lateral ventricle and laterally to the collateral sulcus. This ranked CoA sequence was positively correlated with CoA packing density (count and area fraction) and negatively correlated with CoA minimum diameters (p < 0.05). Although this sequence was not correlated with age or body mass index (BMI), age was positively correlated with the mean and maximum diameters of CoA. These findings support the view that the spatiotemporal sequence of CoA deposition is independent of age, and that CoA become larger due to the accretion of new material over time.
Binocular vision and the control of foot placement during walking in natural terrain
Authors: Bonnen Kathryn , Matthis Jonathan S. , Gibaldi Agostino , Banks Martin S. , Levi Dennis M. , Hayhoe Mary
Published: October 2021

Coordination between visual and motor processes is critical for the selection of stable footholds when walking in uneven terrains. While recent work (Matthis et al. in Curr Biol 8(28):1224–1233, 2018) demonstrates a tight link between gaze (visual) and gait (motor), it remains unclear which aspects of visual information play a role in this visuomotor control loop, and how the loss of this information affects that relationship. Here we examine the role of binocular information in the visuomotor control of walking over complex terrain. We recorded eye and body movements while normally-sighted participants walked over terrains of varying difficulty, with intact vision or with vision in one eye blurred to disrupt binocular vision. Gaze strategy was highly sensitive to the complexity of the terrain, with more fixations dedicated to foothold selection as the terrain became more difficult. The primary effect of increased sensory uncertainty due to disrupted binocular vision was a small bias in gaze towards closer footholds, indicating greater pressure on the visuomotor control process. Participants with binocular vision losses due to developmental disorders (i.e., amblyopia, strabismus), who have had the opportunity to develop alternative strategies, also biased their gaze towards closer footholds. Across all participants, we observed a relationship between an individual’s typical level of binocular visual function and the degree to which gaze is shifted toward the body. Thus the gaze–gait relationship is sensitive to the level of sensory uncertainty, and deficits in binocular visual function (whether transient or long-standing) have systematic effects on gaze strategy in complex terrains. We conclude that binocular vision provides useful information for locating footholds during locomotion. Furthermore, we have demonstrated that combined eye/body tracking in natural environments can be used to provide a more detailed understanding of the impact of a type of vision loss on the visuomotor control process of walking, a vital everyday task.
Aeciospore ejection in the rust pathogen Puccinia graminis is driven by moisture ingress
Authors: Bueno-Sancho Vanessa , Orton Elizabeth S. , Gerrity Morgan , Lewis Clare M. , Davey Phoebe , Findlay Kim C. , Barclay Elaine , Robinson Phil , Morris Richard J. , Blyth Mark , Saunders Diane G. O.
Published: October 2021

Fungi have evolved an array of spore discharge and dispersal processes. Here, we developed a theoretical model that explains the ejection mechanics of aeciospore liberation in the stem rust pathogen Puccinia graminis. Aeciospores are released from cluster cups formed on its Berberis host, spreading early-season inoculum into neighboring small-grain crops. Our model illustrates that during dew or rainfall, changes in aeciospore turgidity exerts substantial force on neighboring aeciospores in cluster cups whilst gaps between spores become perfused with water. This perfusion coats aeciospores with a lubrication film that facilitates expulsion, with single aeciospores reaching speeds of 0.053 to 0.754 m·s−1. We also used aeciospore source strength estimates to simulate the aeciospore dispersal gradient and incorporated this into a publicly available web interface. This aids farmers and legislators to assess current local risk of dispersal and facilitates development of sophisticated epidemiological models to potentially curtail stem rust epidemics originating on Berberis.
The underexposed effect of elastic electron collisions in dusty plasmas
Authors: Staps Tim Jacobus Adrianus , van de Ketterij Marvin Igor , Platier Bart , Beckers Job
Published: October 2021

Dusty plasmas comprise a complex mixture of neutrals, electrons, ions and dust grains, which are found throughout the universe and in many technologies. The complexity resides in the chemical and charging processes involving dust grains and plasma species, both of which impact the collective plasma behavior. For decades, the orbital-motion-limited theory is used to describe the plasma charging of dust grains, in which the electron current is considered collisionless. Here we show that the electron (momentum transfer) collision frequency exceeds the electron plasma frequency in a powder-forming plasma. This indicates that the electron current is no longer collisionless, and the orbital-motion-limited theory may need corrections to account for elastic electron collisions. This implication is especially relevant for higher gas pressure, lower plasma density, and larger dust grain size and density.
Plasmalogens improve swimming performance by modulating the expression of genes involved in amino acid and lipid metabolism, oxidative stress, and ferroptosis in an Alzheimer's disease zebrafish model
Authors: Feng Junli , Song Gongshuai , Wu Yuanyuan , Chen Xi , Pang Jie , Xu Yaxi , Shen Qing , Guo Shunyuan , Zhang Manman
Published: October 2021

Plasmalogens (PLs) are critical to human health.
Cholesterol-lowering activity of protocatechuic acid is mediated by increasing the excretion of bile acids and modulating gut microbiota and producing short-chain fatty acids
Authors: Zhao Yimin , He Zouyan , Hao Wangjun , Zhu Hanyue , Liu Jianhui , Ma Ka Ying , He Wen-Sen , Chen Zhen-Yu
Published: October 2021

The present study aimed to investigate the effects of protocatechuic acid (PCA) on plasma lipid profiles and associated mechanisms with a focus on reshaping gut microbiota.
Synthesis, characterization, and investigation of capacitance and redox properties of self-assembled Phe–Phe with ferrocene conjugates
Authors: Tiwari Om Shanker
Published: October 2021

Conjugated hybrid-peptides of diphenylalanine (Phe–Phe) with ferrocene, a nucleoside and PNA were prepared. The effects of ferrocene conjugation on C-/N-termini on the Phe–Phe motif were explored towards self-assembly and electrochemical properties.
Singlet fission and triplet pair recombination in bipentacenes with a twist
Authors: Yablon Lauren M. , Sanders Samuel N. , Miyazaki Ken , Kumarasamy Elango , He Guiying , Choi Bonnie , Ananth Nandini , Sfeir Matthew Y. , Campos Luis M.
Published: October 2021

We investigate triplet pair dynamics in pentacene dimers that have varying degrees of coplanarity (pentacene–pentacene twist angle).
π–π conjugation promoted nanocatalysis for cancer therapy based on a covalent organic framework
Authors: Yao Shuncheng , Zhao Xingru , Wan Xingyi , Wang Xueyu , Huang Tian , Zhang Jiaming , Li Linlin
Published: October 2021

A π-conjugated structure was designed for triggering efficient catalytic and self-oxygen-supplying PDT activity and realizing complete eradication of cancer. This strategy provides a new way to trigger efficient ROS generation.
Self-supported efficient hydrogen evolution catalysts with a core–shell structure designed via phase separation
Authors: Li Zhibin , Wu Ruoyu , Wen Yuren , Chiang Fu-Kuo , Liu Xiong-Jun , Wang Jing , Li Rui , Wang Hui , Wu Yuan , Jiang Suihe , Wang Xianzhen , Lu Zhao-Ping
Published: October 2021

A physical-metallurgy-based structural design strategy to develop self-supported nanoporous alloy catalysts for efficient hydrogen evolution reaction with a core–shell-like structure is reported in this work.
Double-shell microcapsules with spatially arranged Au nanoparticles and single Zn atoms for tandem synthesis of cyclic carbonates
Authors: Hou Yueming , Wang Xiaomei , Guo Yingchun , Zhang Xu
Published: October 2021

Single-atom Zn catalytic sites and ultrafine Au nanoparticles were orderly encapsulated in mesoporous SiO2, forming double-shell microcapsules for one-pot tandem transforming olefins into cyclic carbonates under mild conditions.
Stimuli-responsive temporary adhesives: enabling debonding on demand through strategic molecular design
Authors: Blelloch Nicholas D. , Yarbrough Hana J. , Mirica Katherine A.
Published: October 2021

Stimuli-responsive temporary adhesives emerge as next-generation multifunctional materials with advantages that include strong temporary adhesion, debonding on demand, and tunable reactivity.
N–H⋯X interactions stabilize intra-residue C5 hydrogen bonded conformations in heterocyclic α-amino acid derivatives
Authors: Mundlapati Venkateswara Rao , Imani Zeynab , D'mello Viola C. , Brenner Valérie , Gloaguen Eric , Baltaze Jean-Pierre , Robin Sylvie , Mons Michel , Aitken David J.
Published: October 2021

In 4-membered ring heterocyclic α-amino acid derivatives, extended conformations based on intraresidue C5 H-bonds can be stabilized by N–H⋯X H-bonds, making the combined C5–C6γ structures prominent in both gas phase and in weakly polar solutions.
Atomic-scale investigation of cation doping and defect clustering in the anti-perovskite Na3OCl sodium-ion conductor
Authors: Goldmann Benedek A. , Clarke Matt J. , Dawson James A. , Islam M. Saiful
Published: October 2021

We reveal the effects of cation doping and dopant-vacancy clustering on Na-ion conductivity in the anti-perovskite Na3OCl solid electrolyte through atomistic simulations.
Long-term cell culture and electrically in situ monitoring of living cells based on a polyaniline hydrogel sensor
Authors: Wu Rong , Li Lanlan , Pan Lijia , Yan Ke , Shi Yi , Jiang Liping , Zhu Jun-Jie
Published: October 2021

Polyaniline hydrogel sensor with carbon cloth was developed for long-term cell culture and monitoring. H2O2 released from cells can be detected to differentiate the physiological states of cells and imitate the different stimuli-responsive behavior.
Efficient green fluorescent organic light-emitting diodes with extended lifetimes by exploiting an iridium complex as a sensitizer
Authors: Cui Rongzhen , Zhou Liang , Zhao Xuesen , Wang Qilin , Liu Fenggang , Wang Jiahai
Published: October 2021

Carriers and excitons in fluorescent organic light-emitting diodes (OLEDs) are modulated by utilizing a phosphorescent material as a sensitizer.
Measurement of relative phase for 5G NR digitally modulated signal using cumulative distribution function
Authors: Kim Dong‐Woo , Kim Kangwook , Jung Young‐Bae , Lim Jong‐Hyuk , Oh Soon‐Soo
Published: October 2021

This letter proposes a measurement technique for the relative phase of a 5G new radio (NR) signal. The total radiated power (TRP) is measured to evaluate wireless equipment. However, this cannot be implemented using the near‐field measurement system owing to the digitally modulated signal. The relative phase detected by using a vector network analyser (VNA) changes significantly owing to the fast change in the signal in the time domain and the imperfect synchronisation of internal receivers of VNA. This study calculated the cumulative distribution function and medium value for the signal from the multi‐probe measurement system. The detected phase agreed well with the exact value obtained from the continuous wave signal. The proposed technique can be used for TRP calculations using the near‐to‐far field transformation.
Design, analysis and implementation of a new three‐port DC‐DC converter with bidirectional capability
Authors: Jalilzadeh Tohid , Rostami Naghi , Babaei Ebrahim , Hosseini Seyed Hossein
Published: October 2021

The proposed converter here is a dual‐input DC‐DC converter with bidirectional power flow. One of the inputs is unidirectional, while the other is a bidirectional port for a battery. The proposed converter can combine two alternating sources with different characteristics. The demanded power of the load can be provided by each input source individually or simultaneously. What is more, the unidirectional port can charge the battery as well as power the output load. Due to the bidirectional capability, the energy returned from the output can be stored in the battery which is suitable for electric vehicle (EV) applications. Step‐up capability, the low voltage stress on semiconductors, and the smaller number of passive elements are the other advantages of the converter. Depending on the battery usage status, four different operation scenarios are defined in the proposed converter. The converter operation is described in each scenario and the mathematical analysis is presented. Based on these, the experimental prototype is conducted to verify the characteristics and feasibilities of the converter.
Modelling method of microgrid system based on multi‐modal dimensions in islanding mode
Authors: Wang Xiaohuan , Huang Peng , Min Fan , Liu Tingwei , Zhao Xiaojun
Published: October 2021

Due to the diverse features of source‐network‐load‐storage for a microgrid, the operation mode of grid‐tied inverter is complicated. The grid net model would be cumbersome and difficult to carry out effective analysis based on uniform model of inverter in accordance with the traditional method. To meet the new IEC/TS 62989 microgrid standard, considering charging and discharging modes of storage unit, a benchmark equivalent model is proposed here by the simplification principle of cluster analysis. Then the microgrid can be divided into multiple source‐network‐load‐storage subsystems based on the model, that helps to carry out the energy independence and modular control of the distributed power generation systems. The simplification of the microgrid module is designed according to the principle of cluster analysis. The simulation and experimental results are given to verify the validity of the model.
Analysis of the impact of Combined Cycle in the energy transition
Authors: Vannoni Alberto , Belotti Daria , Sorce Alessandro , Massardo Aristide Fausto
Published: October 2021

The energy transition of the Italian electrical sector is balancing the objective of renewable energy sources generation increase and the need of maintaining a proper electrical system stability. In the next years, the phase-out of the coal will be covered by an increase of the renewable energy source exploitation supported by natural gas and biogas backup production. In this context, the production of electricity from natural gas, mainly produced by Combined Cycles Gas Turbines (CCGT) plants, that in 2019 covered 48.2% of the Italian electricity generation, will maintain its relevance at national level, even if a more flexible operating profile is envisaged. The use of Combined Cycles as backup power plants will further increase the frequency of transient operating conditions (i.e. start and stop), reducing their load factor and increasing the weight of the emissions related to transient operation with respect to those related to normal operation. In this paper, the operating profile of 45 Italian power-oriented CCGTs are analyzed showing the similarities of management in the different market zones and identifying the main operating patterns. Then a statistical analysis of the emission during normal and transient operation is performed basing on the public available yearly emission statement and highlighting the effect of the CO catalyzer during the transient. Finally, the yearly environmental impact of the flexible operation was assessed and compared to the yearly emission considered during the Environmental Impact Assessment, the Italian VIA (Valutazione di Impatto Ambientale).
Estimation of the Radiative Sky Cooling Potential through Meteorological Data: A Case Study in Tropical Climate
Authors: Merchant Irvin , Chen Austin Miguel , Mora Dafni
Published: October 2021

In search of thermal comfort, over the years, various techniques have been developed to adapt to the conditions of the enclosures, depending on the region and the activity carried out. Thus, this project seeks to evaluate the radiative sky cooling potential for various areas of Panama. This evaluation will be carried out by developing a simplified mathematical model based on meteorological data. An uncertainty-sensibility analysis of the model was also carried out to highlight the critical parameters. Radiative sky cooling systems have been shown to be susceptible to cloudiness and humidity. With a tropical climate, Panama is critical to consider these two variables when developing the simplified mathematical model. Another aspect to consider when estimating the cooling potential will be the hours of the day when there is no solar radiation.
Halving of consumption and energy efficiency of the “Mario Pagano” National boarding school in Campobasso
Authors: Romano Giada , Lallo Francesco Cesare , Mancini Francesco
Published: October 2021

In the national context, Italy with the Integrated National Plan for Energy and Climate (PNIEC) intends to achieve an indicative target of reducing consumption by 2030 equal to 43% of primary energy and 39.7% of final energy compared to the reference scenario of 2007 while with the National Recovery and Resilience Plan (PNRR), the ecological transition will have to be the basis of the new development model on a global scale. To start it up, it will be necessary to drastically reduce emissions of climate-altering gases in line with the objectives of the European Green Deal. Secondly, it will be necessary to improve the energy efficiency of production chains, civil settlements and public buildings and the quality of air in urban centres and water. In light of these ambitious objectives, particular attention is paid to existing buildings: this research has been focused on the is the National Boarding School “Mario Pagano”, an 8,700 m2 school built in 1899, located in the historical centre of Campobasso (Molise).

The effects of the intervention proposals have been simulated in order to evaluate energy savings and the reduction of CO2 emissions. The research is also supported by an economic evaluation that prove the economic sustainability within a period of about 15 years.
CFD Simulation of a Post-Compensated Load Sensing Directional Control Valve
Authors: Fresia Paola , Rundo Massimo
Published: October 2021

The paper presents the CFD model of a load sensing directional control valve. The model was validated experimentally in terms of pressure drop and flow force at different positions of the spool. The spool position was imposed manually by means of a micrometric screw and a load cell was used for measuring the flow force. The CFD model was developed with the CAD-embedded tool FloEFD®. The model has been proved to be very reliable in estimating the pressure drop, moreover quite good results were obtained also in the evaluation of the flow force. The CFD simulations were used to tune the coefficients of a lumped parameter model of the valve, so that such a model can be efficiently used for the simulation of an entire hydraulic circuit. Moreover, the CFD model has been used as design tool for attenuating the detrimental effect of the flow force. In particular, the width of the land upstream of the metering edge has an influence on the resultant force on the spool. If was found that it is possible to significantly reduce the flow force at maximum opening with a relatively small increment of the pressure drop across the valve.
Lumped parameter model of vane pumps developed in OpenModelica environment
Authors: Zardin Barbara , Cillo Giovanni , Rizzoli Marco , Borghi Massimo
Published: October 2021

In this paper, the authors present a 0D fluid dynamic model of a vane pump used to refill tanks with fuel. The model is entirely developed in OpenModelica environment, where the authors have created specific libraries of elements suitable for the physical modelling of fluid power components and systems.

Among the different approaches, the zero-dimension (0D) fluid-dynamic modelling of positive displacement machines is suitable to study many aspects as: the instantaneous flow rate, pressure and torque transients, the fluid borne noise related to the flow rate and pressure irregularity, the dynamic behaviour of the variable displacement control. Overall, this approach in modelling allows to link the geometrical features of the machine with its dynamic behaviour and for this reason is particularly useful in guiding the design.

The model of the vane pump is described together with the main design features that can be analysed in terms of their influence on the pump behaviour.

Besides the specific results obtained regarding the design of the pump, the paper also demonstrates the use of OpenModelica language and environment, and its efficacy, into the applications of fluid power modelling and simulation.
Simulation of a high frequency on/off valve actuated by a piezo-ring stack for digital hydraulics
Authors: Tamburrano Paolo , De Palma Pietro , Plummer Andrew R. , Distaso Elia , Sciatti Francesco , Amirante Riccardo
Published: October 2021

Despite being widely used in several applications, commercially available spool valves, both servovalves and proportional valves, are inefficient components because they cause high power consumption due to the large pressure drops across the metering orifices. A recent research field aims at substituting spool valves with on/off valves having high switching frequency (changing state between open and closed in a few milliseconds or less) and producing low pressure drops, in order to make the so-called digital hydraulics possible. In spite of the advantages that it could provide, digital hydraulics does not have significative industrial applications yet, because of the difficulty in manufacturing such high frequency on/off valves. Hence, this paper performs a feasibility study of an on/off poppet-type valve actuated directly by a commercially available ring stack, which is a multilayer piezo-actuator capable of generating very high actuation forces needed for this application. Modulation of the average flow can be achieved by changing the duty cycle of the pulse width modulation (PWM) signal driving the piezostack. An inertance tube could also be used to smooth flow pulsation. The simulations obtained using a detailed Simulink model show that high switching frequency and very effective flow modulation can be obtained with this valve architecture along with low pressure drops and high flow rates, thus making it potentially suitable for digital hydraulics. The disadvantages of this single stage architecture are the large dimensions of the piezo stacks, and the high current generated because of both the high capacitance of the piezo stack and the high frequency switching. However, large-scale production of these components could help to reduce the costs, and the simulations show that limiting the maximum current to 10 A still provides good regulation.
A 3D-CFD numerical framework for the simulation of both light- and heavy-duty Diesel injectors
Authors: Sparacino Simone , Borghi Massimo
Published: October 2021

In spite of the effort of the engine manufacturers to improve exhaust aftertreatment efficiency, thus reducing tailpipe pollutants, the unaffordable tightening of the laws dealing with emissions puts a strain on the use of Diesel engines for passenger cars in the next decades. However, for trucks and marine applications, such technology may remain the predominant solution all over the world. For this reason, development of heavy-duty Diesel engines goes on and Computational Fluid Dynamics (CFD) can play a crucial role in supporting designers. Among the different goals of the numerical analyses on Diesel engines, 3D-CFD Lagrangian simulations can be adopted to optimize fuel injection, which is a crucial aspects as able to affect both combustion efficiency and emissions. For this purpose, a robust numerical framework is needed. The present work aims at proving that models suitable for the simulation of light-duty Diesel injectors can be proficiently extended for heavy-duty ones. In particular, attention is here focused on droplet break-up. An alternative secondary break-up model is proposed. It is purposely calibrated on the well-known Spray A injector provided by the Engine Combustion Network (ECN), which can be assumed as representative of injectors for light-duty applications. 3D-CFD simulations are validated against experimental data in terms of both liquid and vapour penetrations and imaging. Then, the numerical set-up adopted for the Spray A is employed without any further adhoc tuning to investigate Spray C and Spray D which can be considered, instead, representative of heavy-duty nozzles. The proposed model proves to be effective for the prediction of the break-up rate. All the injectors are tested via vessel simulations characterized by the same ambient pressure and temperature, equal to 6 MPa and 900 K respectively. Even the adopted fuel is common, namely n-Dodecane, whose injection pressure and temperature are fixed to 150 MPa and 363 K, respectively.
Development of a 0D multi-zone model for fast and accurate prediction of homogeneous charge compression ignition (HCCI) engine
Authors: Fasulo Giovanni , Bozza Fabio , Malfi Enrica , Teodosio Luigi
Published: October 2021

Homogeneous Charge Compression Ignition (HCCI) is a promising advanced combustion mode, featured by both high thermal efficiency and low emissions. In this context, a 0D multi-zone model has been developed, where the thermal stratification in the combustion chamber has been taken into account. The model is based on a control mass Lagrangian multi-zone approach. In addition, a procedure based on a tabulated approach (Tabulated Kinetic of Ignition - TKI) has been developed, to perform an accurate and fast prediction of the air/fuel mixture auto-ignition. This methodology allows combining the accuracy of detailed chemistry with a negligible computational effort. The tabulated procedure has been preliminarily verified through the comparison with the results of a commercial software (GT-Power™). In this assessment, single zone simulations have been performed comparing the TKI strategy to a conventional chemical kinetics one, in four different cases at varying the intake temperature and the equivalence ratio. Then, the proposed 0D multi-zone model has been validated against experimental data available in the literature. The analyses are carried out with reference to an HCCI engine fuelled with pure hydrogen and working in a single operating point, namely 1500 rpm, 2.2 bar IMEP and with a fuel/air equivalence ratio of 0.24. Three different temperatures, i.e., 373, 383, and 393 K, have been considered for the intake air. The experimental/numerical comparisons of pressure cycles and burn rates proved that the proposed numerical approach can reproduce the experiments with good accuracy, without the need for case-by-case tuning.
Effect of Lagrangian-phase Modelling on Charge Stratification and Spatial Distribution of Threshold Soot Index for Toluene Reference Fuel Surrogates
Authors: Pessina Valentina , Borghi Massimo
Published: October 2021

Nowadays, soot emissions are one of the major concerns in Direct Injection Spark Ignition engines. Soot prediction models can be computationally expensive, especially when particle mass, number, and size distribution are to be forecast. While soot formation heavily depends on the chemical and physical characteristics of the fuel, the simulation of the exact composition of a real gasoline is computationally unfeasible. Thus, it is essential to find simplified yet representative pathways to reduce the computational cost of the simulations. On the one hand, the a-priori investigation of the factors influencing particulate onset can be a simplified approach to compare different solutions and strategies with much cheaper costs than the modelling of soot formation and oxidation mechanisms. On the other hand, the use of surrogate fuels is a practical approach to cope with the fuel chemical nature. Although they poorly mimic the evaporation properties of a real gasoline, Toluene Reference Fuels are broadly adopted to match combustion relevant properties of the real fuels. In this study, the spatial distribution of the Threshold Soot Index in the fluid domain is investigated for three surrogates characterized by an increasing content of toluene (0 mol%, 30 mol%, 60 mol%). The correlation between the sooting tendency and the fuel distribution in the combustion chamber before spark ignition time can provide useful preliminary indications, without spending the computational effort of the whole soot model multicycle resolution. In particular, two approaches for the lagrangian description of the injected fuel are investigated: a multicomponent approach and a single component one, this last driven by a high-fidelity lumped modelling of the surrogate properties for both liquid and vapor phase.
Preliminary study on the influence of Octane Sensitivity on knock statistics in a GDI engine
Authors: Cicci Francesco , Cantore Giuseppe
Published: October 2021

In the 3D-CFD practice, actual gasoline fuels are usually replaced by surrogate blends composed of Iso-Octane, n-Heptane and Toluene (Toluene Reference Fuels, TRFs). In this work, the impact of surrogate formulation on the probability of end-gas auto-ignition is investigated in a single cylinder engine. CFD simulations are run on equal charge stratification to discern the effect of fuel reactivity from that of evaporation and mixing. Blends are formulated using an internal methodology, coupled with a proprietary method to predict knock statistical occurrence within a RANS framework. Chemical kinetics calculations of Ignition delay times are performed in a 0D constant pressure reactor using a mechanism for gasoline surrogates, proposed by the Clean Combustion Research Center of King Abdullah University of Science and Technology (KAUST), consisting of 2406 species and 9633 reactions. Surrogates mimic a commercial European gasoline (ULG95). Five different formulations are presented. Three are characterised by equal RON (95) with progressively decreasing Octane Sensitivity S. The fourth and the fifth have a sensitivity of 10 but with lower RON (92.5 and 90). The combinations allow the reader to separate the effects of octane sensitivity from those of RON quality of the tested fuels. Applying the different surrogates, changes in each of autoignition phasing, magnitude and statistical probability are investigated. Results confirm the dependency of knock occurrence on the Octane Sensitivity, as well as the need to include engine-specific and operation-specific characteristics in the analysis of knock. The Octane Index (OI) formulation developed by Kalghatgi is discussed.
Triple-screw pumps for ICE cooling systems in the transportation sector
Authors: Di Giovine Giammarco , Mariani Luigi , Di Bartolomeo Marco , Di Battista Davide , Cipollone Roberto
Published: October 2021

Recent EU Regulations have been pushing the transportation sector increasingly towards the reduction of primary harmful pollutants and CO2 emissions. In this context, the Internal Combustion Engine (ICE) cooling system is gaining a new technological interest. In fact, improvements on pump efficiency can significantly reduce its absorbed energy during real on-the-road operation. Typically, centrifugal pumps are adopted, but their efficiency is highly dependent on rotational speed, wasting energy during real operation, even if they are designed to have a very high efficiency at the design point. This study investigates the three screws pumps potentiality to substitute traditional centrifugal pumps in engine cooling applications. In fact, triple-screw pumps belong to positive displacement pumps, which have an efficiency ideally independent on rotational speed.

A zero-dimensional mathematical model of this pump previously developed by the authors was improved, giving a specific focus on the mechanical efficiency of the pump. The validation of the model resulted in a good agreement with experimental results. The model has been used to design a pump for an IVECO F1C diesel engine. The energy requested to drive the pump over a Worldwide Harmonized Light Vehicles Test Cycle (WLTC) has been calculated and compared with that of the traditional existing centrifugal pump. Results show that the electrically actuated triple screw pump allows to reduce the energy of about 14 %.
Combined Heat and Power generation exploiting the biogas production from urban wastewaters treatment: the Genoa case study
Authors: Borelli Davide , Devia Francesco , Schenone Corrado , Silenzi Federico , Tagliafico Luca
Published: October 2021

Wastewaters treatment with biological processes is widely applied as a reliable solution to water pollution in urban areas. This process produces sludges and process waters. Sludges can be furtherly threated in dedicated plants to produce biogas, that can then be used to produce heat in specific plants, but it is sometimes simply burned using flares. A possible alternative use of biogas is the coupling with a CHP generator which can be used to produce electrical energy and heat. In the present paper, it is investigated the possible exploitation of the sludges produced by a wastewater treatment plant for feeding a sludge treatment plant, both in Genoa (Italy), in order to produce biogas. This work is based on the analysis of available data (2009-2018) provided by the sludge treatment plant technical staff, which showed strong variations in sludge flow rates as a result of the variation of incoming wastewater load. Since the available data is not always correlated with wastewater incoming flows and biogas production, starting from data provided for similar plants operating in Italy, it was possible to estimate a theoretical biogas production which was considered as the reference trend.