bluuebunny/crossref_metadata_2025 huggingface dataset:
Positional and compositional analysis of saturated, monounsaturated, and polyunsaturated fatty acids in human adipose tissue triglyceride by 13C nuclear magnetic resonance
Authors: Torres Alejandra N. , Tavares Ludgero , Pereira Maria J. , Eriksson Jan W. , Jones John G.
Published: October 2021

The synthesis and turnover of triglyceride in adipose tissue involves enzymes with preferences for specific fatty acid classes and/or regioselectivity regarding the fatty acid position within the glycerol moiety. The focus of the current study was to characterize both the composition of fatty acids and their positional distribution in triglycerides of biopsied human subcutaneous adipose tissue, from subjects with wide ranges of body mass index (BMI) and insulin sensitivity, using 13C nuclear magnetic resonance (NMR) spectroscopy. The triglyceride sn2 position was significantly more enriched with monounsaturated fatty acids compared with that of sn1,3, while the abundance of saturated fatty acids was significantly lower in the sn2 position compared with that of sn1,3. Furthermore, the analysis revealed significant positive correlations between the total fraction of palmitoleic acid with both BMI and insulin sensitivity scores (homeostatic model assessment of insulin resistance index). Additionally, we established that 13C NMR chemical shifts for ω‐3 signals, centered at 31.9 ppm, provided superior resolution of the most abundant fatty acid species, including palmitoleate, compared with the ω‐2 signals that were used previously. 13C NMR spectroscopy reveals for the first time a highly nonhomogenous distribution of fatty acids in the glycerol sites of human adipose tissue triglyceride, and that these distributions are correlated with different phenotypes, such as BMI and insulin sensitivity.
Analgesic effects of medicinal plants and phytochemicals on chemotherapy‐induced neuropathic pain through glial modulation
Authors: Lee Ji Hwan , Kim Nari , Park Sangwon , Kim Sun Kwang
Published: October 2021

Chemotherapy‐induced peripheral neuropathy (CIPN) frequently occurs in cancer patients. This side effect lowers the quality of life of patients and may cause the patients to abandon chemotherapy. Several medications (e.g., duloxetine and gabapentin) are recommended as remedies to treat CIPN; however, usage of these drugs is limited because of low efficacy or side effects such as dizziness, nausea, somnolence, and vomiting. From ancient East Asia, the decoction of medicinal herbal formulas or single herbs have been used to treat pain and could serve as alternative therapeutic option. Recently, the analgesic potency of medicinal plants and their phytochemicals on CIPN has been reported, and a majority of their effects have been shown to be mediated by glial modulation. In this review, we summarize the analgesic efficacy of medicinal plants and their phytochemicals, and discuss their possible mechanisms focusing on glial modulation in animal studies.
Chemogenetic stimulation of the Gi pathway in astrocytes suppresses neuroinflammation
Authors: Kim Jae‐Hong , Rahman Md Habibur , Lee Won Ha , Suk Kyoungho
Published: October 2021

Engineered G protein‐coupled receptors (GPCRs) are commonly used in chemogenetics as designer receptors exclusively activated by designer drugs (DREADDs). Although several GPCRs have been studied in astrocytes using a chemogenetic approach, the functional role of the astrocytic Gi pathway is not clear, as the literature is conflicting depending on the brain regions or behaviors investigated. In this study, we evaluated the role of the astrocytic Gi pathway in neuroinflammation using a Gi‐coupled DREADD (hM4Di). Gi‐DREADD was expressed in hippocampal astrocytes of a lipopolysaccharide (LPS)‐induced neuroinflammation mouse model using adeno‐associated viruses. We found that astrocyte Gi‐DREADD stimulation using clozapine N‐oxide (CNO) inhibits neuroinflammation, as characterized by decreased levels of proinflammatory cytokines, glial activation, and cognitive impairment in mice. Subsequent experiments using primary astrocyte cultures revealed that Gi‐DREADD stimulation significantly downregulated LPS‐induced expression of Nos2 mRNA and nitric oxide production. Similarly, in vitro calcium imaging showed that activation of the astrocytic Gi pathway attenuated intracellular calcium transients triggered by LPS treatment, suggesting a positive correlation between enhanced calcium transients and the inflammatory phenotype of astrocytes observed in the inflamed brain. Taken together, our results indicate that the astrocytic Gi pathway plays an inhibitory role in neuroinflammation, providing an opportunity to identify potential cellular and molecular targets to control neuroinflammation.
Responses of the atmospheric boundary layer to a low‐latitude mesoscale SST front
Authors: Zhao Zhongkuo , Bi Xueyan , Dudhia Jimy , Luo Yali , Song Jinbao , Song Qingtao , Wu Naigeng
Published: October 2021

The responses of the atmospheric boundary layer at low latitudes (20°N) to forcing by an ocean‐mesoscale sea surface temperature (SST) front are investigated under the conditions that the background wind intersects with the SST front (i.e., there are cross‐frontal and along‐frontal wind components) through ideal numerical experiments. The simulation results show that the responses of the atmospheric boundary layer are sensitive to the background wind speed and its direction relative to the SST front. The type of convergence and divergence of Ekman transport and that of the background wind can be constructive or destructive, depending on the relative orientation of the background wind and the SST front. When the two kinds of convergence and divergence are constructive, they can cause strong convergence and divergence in the boundary layer near the SST front; further, the unbalanced state forced over the SST front will excite inertial gravity waves propagating into the free atmosphere. The vertical velocity excited in this case is much greater than that when there is only a cross‐frontal background wind component with an equivalent magnitude. On the contrary, when the two kinds of convergence and divergence are destructive, the resultants of convergence and divergence are reduced significantly, and the interaction between the boundary layer and the aloft atmosphere decays rapidly with height. The significance of the results obtained for the analysis of coastal precipitation are discussed.
The size effect and default risk: Evidence from the Vietnamese stock market
Authors: Quy Duong Le , Bertrand Philippe
Published: October 2021

The literature is inconclusive on the source of the size effect. Our paper contributes to extant studies by investigating the relationship between the size premium and default risk in Vietnam, an important frontier emerging market. The debt‐to‐equity ratio and distance‐to‐default of Merton (1974, The Journal of Finance, 29, 449) are used as distress‐risk proxies. Based on more than 300 listed stocks over 2009–2019, we discover that the small portfolio delivers the highest average return. The excess return on the small portfolio is concentrated in firms with high distress risk. Furthermore, neutral size factors are built to dissect returns on the Fama‐French size factor from the default‐risk premium. Empirical results prove that the explanatory power of the size factor is negatively affected when the default‐risk neutrality is applied. Given this backdrop, the size premium in Vietnam is likely to be compensation for distress risk, consistent with a risk‐based point of view.
Three‐Component Acylation/Peroxidation of Alkenes through Visible‐Light Photocatalysis
Authors: Zhao Dengyang , Pan Yingjie , Chen Xiaoyun , Han Ying , Yan Chaoguo , Shi Yaocheng , Hou Hong , Zhu Shaoqun
Published: October 2021

A three‐component acylation/peroxidation of alkenes through visible‐light photocatalysis was described. The acyl radical was generated by a hydrogen atom transfer process and enabled the radical addition and peroxidation. Various indole‐3‐carbaldehyde and styrene derivatives were subjected to the current visible light photochemical conditions, delivering β‐peroxy‐ketones in moderate to good isolated yields.
l‐cysteine‐modified Fe3O4 nanoparticles as a novel heterogeneous catalyst for persulfate activation on BTEX removal
Authors: Sun Xuecheng , Lyu Shuguang
Published: October 2021

l‐cysteine‐modified Fe3O4 nanoparticles (l‐cys@nFe3O4) were synthesized successfully and used as catalyst to activate persulfate (PS) for benzene, toluene, ethylbenzene, and xylenes (BTEX) degradation. The composite was fully characterized, and the l‐cys@nFe3O4 had more protrusions and l‐cys was combined on the surface of nFe3O4. The removals of BTEX were 78.2%, 85.1%, 85.3%, 81.2%, respectively, in PS/l‐cys@nFe3O4 system, while only 52.7% 57.8%, 60.8%, and 56.3% of BTEX removals reached under the same condition for nFe3O4 chelated with l‐cys in 48 h. Four successive cycles of BTEX degradation were completed in PS/l‐cys@nFe3O4 system. The synergistic mechanisms of BTEX degradation in PS/l‐cys@nFe3O4 system were investigated by electron paramagnetic resonance (EPR), benzoic acid (BA) probe and X‐ray photoelectron spectroscopy (XPS) tests. SFe bond in l‐cys‐Fe complexes promoted the electron transfer between nFe3O4 core and the solution, iron and iron at the interface, thereby promoting the Fe3+/Fe2+ cycle and the catalytic capacity of nFe3O4. The optimal pH of PS/l‐cys@nFe3O4 system was 3, while HCO3− and Cl− exhibited negative influences on BTEX degradation. Only 14.2%, 15.5%, 15.9%, and 15.6% BTEX had been removed in the presence of 0.12‐M PS and 8.0 g/L l‐cys@nFe3O4 under the actual groundwater condition. However, expanding the dosage of PS and l‐cys@nFe3O4 was an effective strategy to overcome the adverse effect.

Practitioner Points

L‐cys@nFe3O4 were synthesized successfully and used as catalyst to activate PS for BTEX degradation.

Four successive cycles of BTEX degradation were completed in PS/L‐cys@nFe3O4 system.

lS―Fe bond in L‐cys@nFe3O4 promoted the electron transfer between PS and nFe3O4 core.
Formal scheduling method for zero-defect manufacturing
Authors: Grobler-Dębska Katarzyna , Kucharska Edyta , Baranowski Jerzy
Published: October 2021

A defect prevention is a part of manufacturing company practice. Paper proposes a formal approach for solving scheduling problems with unexpected events as extension of general frameworks for Zero-Defect Manufacturing (ZDM) strategy. ZDM aims to improve the process efficiency and the product quality while eliminating defects and minimizing process errors. However, most of ZDM applications focus on using the technological achievements of Industry 4.0 to detect and predict defects, forgetting to optimize the schedule on the production line. We propose formal method to create predictive-reactive schedule for problems with defect detection and repair. Our proposal is based on the formal Algebraic-Logical Meta-Model (ALMM). In particular, it uses the model switching method and combines defect detection, heuristics construction and decision support containing predictions of disturbances in the production process and enabling their prevention. Production defects are detected and repaired, and consequently, production delivers components without defects, and in the shortest possible time. Moreover, the collection and analysis of data related to the occurrence of disturbances in the production process helps the management board in making decisions based on analysis gathered and stored data. Thus, the proposed method includes strategies such as detection, repair, prediction and prevention for defect-free production. We illustrate the proposed method on the example of a flow-shop system with different types of product defect problem.
Supervise me if you can. Relational feelings, incentive pays and supervisory violations
Authors: Dughera Stefano , Marciano Alain
Published: October 2021

We study a bonus pay setting where a principal hires a supervisor to evaluate a group of potentially shirking workers. The supervisor and her workers develop relational feelings (either positive or negative) after interacting with each other. We analyze a novel class of organizational infractions where the supervisor provides false evaluations of the workers’ performance to accommodate her other-regarding preferences. We show that the workers’ reaction to these supervisory violations and their decision to provide effort depend on their relational concerns. The implication is that incentive pays can be ineffective due to the distortion of relational concerns.
Bayesian dynamic network actor models with application to South Korean COVID-19 patient movement data
Authors: Arrizza Antonio Mario , Caimo Alberto
Published: October 2021

Motivated by the ongoing COVID-19 pandemic, this article introduces Bayesian dynamic network actor models for the analysis of infected individuals’ movements in South Korea during the first three months of 2020. The relational event data modelling framework makes use of network statistics capturing the structure of movement events from and to several country’s municipalities. The fully probabilistic Bayesian approach allows to quantify the uncertainty associated to the relational tendencies explaining where and when movement events are established and where they are directed. The observed patient movements’ patterns at an early stage of the pandemic can provide interesting insights about the spread of the disease in the Asian country.
A case of esophageal granular cell tumor diagnosed by mucosal incision-assisted biopsy
Authors: Inokuchi Yasuhiro , Watanabe Mamoru , Hayashi Kei , Kaneta Yoshihiro , Furuta Mitsuhiro , Machida Nozomu , Maeda Shin
Published: October 2021

For an esophageal submucosal mass suspicious of granular cell tumor (GCT) based on gross appearance and endoscopic ultrasound findings, a sufficient number of biopsy specimens is required for a definite diagnosis using immunohistochemical examination. When the specimen obtained by forceps biopsy is insufficient, endoscopic ultrasound-fine needle aspiration (EUS-FNA) is believed to be an useful alternative. However, it may be difficult to obtain an adequate amount of tumor material using EUS-FNA. Mucosal incision-assisted biopsy (MIAB) is a simple method that can collect larger amounts of specimens. This procedure is helpful for physicians who encounter the problem of obtaining an adequate amount of biopsy material from esophageal tumors suspicious for GCT. We present a case of esophageal GCT that was successfully diagnosed through MIAB.
New Adult Fiction
Authors: McAlister Jodi
Published: October 2021

The term 'new adult' was coined in 2009 by St Martin's Press, when they sought submissions for a contest for 'fiction similar to YA that can be published and marketed as adult – a sort of 'older YA' or 'new adult'.' However, the literary category that later emerged bore less resemblance to young adult fiction and instead became a sub-genre of another major popular genre: romance. This Element uses new adult fiction as a case study to explore how genres develop in the twenty-first-century literary marketplace. It traces new adult's evolution through three key stages in order to demonstrate the fluidity that characterises contemporary genres. It argues for greater consideration of paratextual factors in studies of genre. Using a genre worlds approach, it contends that in order to productively examine genre, we must consider industrial and social factors as well as texts.
When the Complexity of the Large-Scale Development Project Becomes a Roadblock to Access to Justice
Authors: HWANG Pillkyu , PARK Yae-Ahn
Published: October 2021

On 23 July 2018, when the villagers gathered around the porch to wrap up the day with a good chat, one of the five auxiliary dams of the Xe-Pian Xe-Namnoy hydropower dam in Attapeu province, the southeastern state of Laos, collapsed. Four days before the collapse, reports of cracks and subsidence started to come through. It should have been enough to prompt evacuation warning issuance by the Xe-Pian Xe-Namnoy Power Co. Ltd (PNPC), a consortium of South Korean companies SK Engineering and Construction (SK E&C) and Korea Western Power Company (KOWEPO), Thailand-based RATCH Group, and Lao Holding State Enterprise (LHSE). PNPC has a Concession Agreement with the Laos government ‘to plan, design, finance, construct, own, operate and maintain’ the Xe-Pian Xe-Namnoy hydropower dam. The warning was issued, but it came too late.
Gefahr einer Mangelernährung älterer Patient_innen im Akutspital
Authors: Brunner Silvia , Mayer Hanna , Dietrich Michael , Breidert Matthias , Blum Karin , Müller-Staub Maria
Published: October 2021

Zusammenfassung. Hintergrund: Die Gefahr einer Mangelernährung ist bei hohem Alter und akuter Erkrankung erhöht und deren Erfassung sowie bedarfsgerechte Unterstützung gehören zum Verantwortungsbereich der Pflege. Fragestellung / Ziel: Mit der folgenden Forschungsfrage sollen Ernährungszustand sowie mögliche Zusammenhänge zu Pflegediagnosen und weiteren Patient_innen-Merkmalen von Personen (80-jährig und älter) analysiert werden: Welche Muster im Sinne von Zusammenhängen lassen sich in Bezug auf Kalorien- und Proteinbedarfsdeckungsgrade und weiteren Patient_innen-Merkmalen erkennen? Methoden: Explorative Querschnittsstudie mit Clusteranalyse auf Grundlage von Essprotokollen und Pflegedokumentationen. In die Gelegenheitsstichprobe eingeschlossen wurden Patient_innen der Behandlungsbereiche Chirurgie, inneren Medizin und universitäre Akutgeriatrie. Ergebnisse: Aus Daten von 135 Patient_innen wurden vier Gruppen gebildet (Proteinbedarfsdeckungsgrad): Gut-Ernährte (116 %), Genügend-Ernährte (77 %), Ungenügend-Ernährte (59 %) und Schlecht-Ernährte (40 %). Ein signifikanter Zusammenhang von Kalorien-und Proteinbedarfsdeckungsgrad und Behandlungsbereich konnte gezeigt werden. Schlussfolgerungen: Protein- und Kalorienbedarfsdeckungsgrade hängen mit dem Behandlungsbereich und folglich mit dessen Teamkultur und Behandlungskonzept zusammen. Aufgrund der Eigenschaften der Gut-Ernährten kann auf eine positive Wirkung der interprofessionellen Zusammenarbeit und der systematischen Erfassung der Gefahr einer Mangelernährung, wie es im Bereich Akutgeriatrie umgesetzt wird, geschlossen werden.
How Are Under Ice Phytoplankton Related to Sea Ice in the Southern Ocean?
Authors: Bisson K. M. , Cael B. B.
Published: October 2021

Little is known about Southern Ocean under‐ice phytoplankton, despite their suspected potential—ice and stratification conditions permitting—to produce blooms. We use a distributional approach to ask how Southern Ocean sea ice and under‐ice phytoplankton characteristics are related, circumventing the dearth of co‐located ice and phytoplankton data. We leverage all available Argo float profiles, together with freeboard (height of sea ice above sea level) and lead (ice fractures yielding open water) data from ICESat‐2, to describe co‐variations over time. We calculate moments of the probability distributions of maximum chlorophyll, particulate backscatter, the depths of these maxima, freeboard, and ice thickness. Argo moments correlate significantly with freeboard variance, lead fraction, and mixed layer depth, implying that sea ice dynamics drive plankton by modulating how much light they receive. We discuss ecological implications in the context of data limitations and advocate for diagnostic models and field studies to test additional processes influencing under‐ice phytoplankton.
Development, implementation and feedback for an online speciality membership examination in orthodontics during the COVID-19 pandemic
Authors: Eckhardt Charlotte E. , Seehra Jadbinder , Chadwick Stephen M. , Voerman Kim , Landau Alex , Ryan Fiona S. , Fleming Padhraig S. , Garrett Matthew , Cobourne Martyn T.
Published: October 2021

Introduction The Royal College of Surgeons of England (RCSEng) and the Royal College of Physicians and Surgeons of Glasgow (RCPSG) offer the bi-collegiate Membership in Orthodontics (MOrth) examination, a summative assessment of specialist knowledge, skill and behaviour in orthodontics. The COVID-19 pandemic has had a profound global effect on almost every facet of normal life, including the conduct of face-to-face examinations. We highlight development, implementation and feedback for the bi-collegiate MOrth Part 2 examination delivered remotely to a cohort of candidates in September 2020 by RCSEng/RCPSG.

Methods Two anonymised online surveys (Google Forms) were distributed via electronic mail following completion of the examination diet. Forty-two candidates were sent a survey covering four domains and comprising a total of 31 questions. The 20 examiners were sent a survey containing eight questions. In both surveys, free-text responses were also collected. A rating system was used to categorise responses. All survey responses were summarised in an online data collection sheet.

Results The response rate was 78.5% (33/42) and 75% (15/20) for candidates and examiners, respectively. Overall, favourable responses in relation to all sections of the assessment were elicited from candidates with the majority (mean 79.8%; 75.8-81.9%) reporting that the online examination format worked well. Equally, favourable responses were reported by examiners. Notably, 80% of examiners felt that the online exam style did not affect the mark a candidate would receive, and 100% were confident that the marks the candidates received were a reflection of their ability and were not affected by the online delivery of the assessment.

Conclusions The feedback from both candidates and examiners relating to an online remote assessment of the bi-collegiate MOrth Part 2 was generally positive. Based on the survey responses, this format of a high-stakes examination was acceptable to all stakeholders, and demonstrated a high level of perceived validity and reliability in terms of content.
Bar-cas12a, a novel and rapid method for plant species authentication in case of Phyllanthus amarus Schumach. & Thonn
Authors: Buddhachat Kittisak , Paenkaew Suphaporn , Sripairoj Nattaporn , Gupta Yash Munnalal , Pradit Waranee , Chomdej Siriwadee
Published: October 2021

Rapid and accurate species diagnosis accelerates performance in numerous biological fields and associated areas. However, morphology-based species taxonomy/identification might hinder study and lead to ambiguous results. DNA barcodes (Bar) has been employed extensively for plant species identification. Recently, CRISPR-cas system can be applied for diagnostic tool to detect pathogen’s DNA based on the collateral activity of cas12a or cas13. Here, we developed barcode-coupled with cas12a assay, “Bar-cas12a” for species authentication using Phyllanthus amarus as a model. The gRNAs were designed from trnL region, namely gRNA-A and gRNA-B. As a result, gRNA-A was highly specific to P. amarus amplified by RPA in contrast to gRNA-B even in contaminated condition. Apart from the large variation of gRNA-A binding in DNA target, cas12a- specific PAM’s gRNA-A as TTTN can be found only in P. amarus. PAM site may be recognized one of the potential regions for increasing specificity to authenticate species. In addition, the sensitivity of Bar-cas12a using both gRNAs gave the same detection limit at 0.8 fg and it was 1,000 times more sensitive compared to agarose gel electrophoresis. This approach displayed the accuracy degree of 90% for species authentication. Overall, Bar-cas12a using trnL-designed gRNA offer a highly specific, sensitive, speed, and simple approach for plant species authentication. Therefore, the current method serves as a promising tool for species determination which is likely to be implemented for onsite testing.
A modular strategy for the synthesis of marine originated meroterpenoid-type natural products
Authors: Wang Hong-Shuang , Nan Xiang , Li Hui-Jing , Cao Zhong-Yan , Wu Yan-Chao
Published: October 2021

Chemoselective formal synthesis of (−)-pelorol and 9-epi-pelorol was achieved by controlling the reaction sequence of hydrogenation and cyclization. Synthesis of (+)-yahazunone and (+)-yahazunol was also accomplished using palladium-catalyzed tandem carbene migratory insertion.
Characterisation and heterologous biosynthesis of burnettiene A, a new polyene-decalin polyketide from Aspergillus burnettii
Authors: Roux Indra , Bowles Simon , Kalaitzis John A. , Vuong Daniel , Lacey Ernest , Chooi Yit-Heng , Piggott Andrew M.
Published: October 2021

Burnettiene A is a novel cytotoxic tridecaketide decalin polyketide from Aspergillus burnettii. Its biosynthesis was elucidated by heterologous expression in fungi.
Lamellar-to-MLV transformation in SDS/octanol/brine examined by microfluidic-SANS and polarised microscopy
Authors: Donina Liva , Rafique Aysha , Khodaparast Sepideh , Porcar Lionel , Cabral João T.
Published: October 2021

The lamellar-to-multilamellar vesicle (MLV) transformation in a model surfactant system, SDS/octanol/brine, is investigated under continuous and oscillatory microfluidic contraction–expansion flows, employing polarised optical microscopy and SANS.
A parametric study of implementing green roofs to improve building energy performance in tropical climate
Authors: Moreno Agnieszka , Austin Miguel Chen , Mora Dafni
Published: October 2021

Energy is one of the most involving issues, its use, the way to spread it, and how to reduce its consumption. Because of this, it is important to opt for solutions that determine the final use of energy. The feasibility study of vegetation applied to green roofs for buildings would be a favorable solution to stop absorbing the heat that we consume daily, and at the same time, we produce. Thus, this research aims to evaluate the implementation of generic vegetation on the roof of buildings in Panama, in terms of electricity consumption for cooling, through dynamic simulation. For this, a parametric analysis was performed through the DesignBuilder program, where four plants suitable for the climate of Panama and resistant to solar radiation, high temperatures, and humidity were chosen, which were Tradescantia spathacea Sw., Sansevieria sp., Aloe Vera, and Arachis hypogaea. Employing passive and mechanical mode simulations with 24-hour irrigation systems, it was possible to observe how the temperature inside the building and the heat gains through the roof decrease. This led us to determine the most important parameters of the vegetation layer: plant height, leaf area index (LAI), leaf reflectivity, and stomatal resistance.
Achieving near Zero Energy Building in Albania: An Approach for the Retrofit of a Public-School Building
Authors: Belussi Lorenzo , Danza Ludovico , Ghellere Matteo , Meroni Italo , Salamone Francesco , Shtylla Arben , Dobjani Etleva , Shtylla Saimir
Published: October 2021

Since its introduction in 2010, the nearly Zero Energy Building (nZEB) concept has known a large diffusion in European countries. Albania, an aspiring candidate country to join the European Union EU, is paving the way towards its introduction by transposing EU directives in the fields of energy efficiency into the national legislation. Most of the national building stock includes buildings with low thermal and energy performance but with high refurbishment potential, too. The country can become an important contributor in the EU decarbonization strategy due to the high percentage of electricity produced by hydropower stations, making it one of the least carbon-intensity countries in the electricity production point of view. The article focuses on the evaluation of the energy performance of an existing school located in Tirana and the potentialities to reach the nZEB target, analysing both the suitable technological solutions and the energy market situation. The Primary Energy Factors PEF for the local electricity market are estimated referring to statistical data and in comparison, with neighbouring countries, Italy and Greece, in order to investigate the potential of the achievement of the nZEB target in Albania.
Application of hourly dynamic method for nZEB buildings in Italian context: analysis and comparisons in national calculation procedure framework
Authors: Palladino Domenico , Iatauro Domenico , Signoretti Paolo
Published: October 2021

The Energy Performance of Buildings Directive (EPBD 2018/844/EU) requires to Member States to upgrade the methodology for the energy performance assessment of buildings. The current calculation method, based on the monthly quasi steady state calculation procedure, could be replaced in the next years by an hourly dynamic calculation procedure (EN ISO 52016), in which a resistance-capacity (RC) model is implemented to consider with more accuracy the heat exchange through the building envelope. In this framework, the present work aims at analysing and comparing the energy needs of three reference case studies of nearly Zero Energy Buildings (nZEB), applying both calculation procedures in order to investigate the main difference of the two approaches. Two residential buildings and one office, compliant with Italian minimum requirements for nZEB, were defined, and several energy simulations were carried out for all different climatic zones of Italian territory. Preliminary results highlighted significant differences of energy need mainly due to different weight of heat loss and heat gains obtained with the two considered calculation methods. This paper represents a preliminary study, but further analysis are recommended in order to evaluate the overall energy use for different type and different operation profile of buildings.
Energy optimization analysis of archetype public buildings – Results from SHERPA European Project
Authors: de Rubeis Tullio , Nardi Iole , Paoletti Domenica , Ambrosini Dario
Published: October 2021

In this paper, the main results obtained for the identification of energy efficiency measures (EEMs) in archetype public buildings selected by the Abruzzo Region within the European Project SHERPA (SHared knowledge for Energy Renovation in buildings by Public Administration), a three-year project involving 12 partners from the Mediterranean area, are presented.The analysis presented in this work was carried out on 12 public buildings, with different intended use, located in the four provinces of the Abruzzo Region characterized by different climate conditions. For each building, a complex work of documents acquisition has been carried out together with the regional coordinators of the Project. These documents have allowed the energy assessment of the selected buildings in their current condition. The second phase of the study has instead focused on the effects resulting from the application of EEMs on both passive and active components, in terms of energy savings and greenhouse gas (GHG) emissions reduction. The results obtained have permitted to compare different public buildings, in different climate conditions, identifying EEMs and achievable results that may be useful to policy makers for the identification of appropriate energy optimization strategies and financial instruments for their implementation.
The hybrid method for the plate-finned tube evaporator design process
Authors: Starace Giuseppe , Macchitella Silvia , Colangelo Gianpiero
Published: October 2021

The plate-finned tube evaporator performance, in terms of heat transfer rate and refrigerant pressure drops, is influenced by several choices done during the design process to be carried out complying with different constraints. In this paper different refrigerant circuitry layout options together with other parameters variations were investigated with the purpose of supporting designers. Performance predictions were calculated using the hybrid method as well as appropriate Performance Evaluation Criteria (PEC) were adopted to select the best layout. The hybrid method has been here revised and improved aiming at modelling heat exchangers with an approach closer to real configurations that include complex circuit layouts. The method was chosen as its main advantage (high accuracy in the results with low computational costs) allowed to easily perform operating conditions modifications to be compared.
Field study on heat pump monitoring: challenges and opportunities
Authors: Nardi Iole , Lavinia Carmen , Iatauro Domenico , Calabrese Nicolandrea
Published: October 2021

In view of the decarbonisation targets in the building sector, heat pump can play a key role, marking the shift towards all-electric buildings. Although the heat pump technology is well known, and its use is ever increasing, some issues (practical and operative) are still open in the assessment of the main aspects that influence the efficiency. These complexities emerge when heat pump monitoring is carried out, allowing to assess the real performance. Therefore, in this work, the challenges and opportunities of heat pump monitoring are presented, from a field study of the tertiary sector. The monitoring of an air-to-water heat pump allowed to: (i) assess its real operating performance; (ii) compare the correlations of results with climate data and load profile; (iii) highlight some critical points, as the importance of data mining and data cleaning phase for the reliability of the results; (iv) assess and identify which is the temporal scale needed for a proper data elaboration.
Dynamic behaviour and stability analysis of a compensated aerostatic pad
Authors: Colombo Federico , Lentini Luigi , Raparelli Terenziano , Trivella Andrea , Viktorov Vladimir
Published: October 2021

Thanks to their low friction, aerostatic pads have important applications in precision positioning systems and linear guides. A simple and cheap solution to increase the static stiffness of aerostatic pads is to add a proper designed pneumatic valve to regulate the air flow supplied to the bearing. However, integrating aerostatic pads with additional devices can reduce its dynamic performance. This paper presents a numerical study on the dynamic behaviour and stability a commercial aerostatic pad controlled by a custom-built diaphragm valve. The bearing performance is studied by means of a lumped parameters model. Air bearing stiffness and damping are analysed in the frequency domain. Subsequently, the lumped model is linearized to investigate the stability of the system by means of Routh-Hurwitz method. The performance of the controlled air pad is compared to that of a simple commercial air pad.
Evaluation of the energy performance of Zero Energy residential Buildings: complexity of dynamic simulations and results variability
Authors: Di Turi Silvia , Falcone Ilaria , Nardi Iole , Ronchetti Laura , Calabrese Nicolandrea
Published: October 2021

Due to its energy and environmental impact, the building sector has become a challenging field in order to fulfil the need for energy renovation and obtain low-consumption buildings. The main issue, for those who approach the feasible design of a Zero Energy Building (ZEB), is to assess, in the most realistic way possible, the thermal and energy needs and the energy production of the building, properly considering all the possible variables. Through the analysis of a newly built residential building case study, this work aims at showing the complexity of the ZEB design, analysing the energy performance as the design choices vary. After characterizing envelope and systems components, potential variations in the model are highlighted by applying a set of updated climatic data, varying occupancy, shading systems and natural ventilation functioning, often neglected. It leads to a wide and differentiated range of results, consequently influenced by the design phase. The work aims at providing, in the definition of the energy performance of the building, an evaluation of the variations obtained from the variables analysed that in the modelling phase are normally considered as a boundary but which instead play a key role for achieving the ZEB objective.
A Numerical Exploration of Engine Combustion Using Toluene Reference Fuel and Hydrogen Mixtures
Authors: Barbato Alessio , Pessina Valentina , Borghi Massimo
Published: October 2021

Hydrogen-fueled internal combustion engines (H2ICEs) are capable of operating over a wide range of equivalence ratios: from ultra-lean mode to stoichiometric conditions. However, they provide maximum thermal efficiency and minimum NOx emissions if operated lean. Although NOx is produced, H2ICEs generate little or no CO, CO2, SO2, HC, or PM emissions. The main limitation to pure hydrogen fueling is power density. To overcome such an issue, mixtures of gasoline and hydrogen can be exploited, with small modifications to the engine feeding system. Due to the peculiar characteristics of hydrogen (in terms of thermophysical properties, molecular weight and propagating flame characteristics) care must be adopted when trying to address combustion using computational fluid dynamics (CFD) tools. In this work, we simulate the combustion of mixtures of toluene reference fuel (TRF) and hydrogen under largely different ratios. To simplify the problem, liquid and gaseous injections are neglected, and a premixed mixture at the inlet of the CFD domain is imposed. Due to the different laminar flame speeds of the mixture components, mass-fraction weighted in-house correlations based on chemical kinetics simulations are adopted. Outcomes are compared with those obtained using standard correlations and mixing rules available in most commercial CFD packages.
Investigation of the wake energy recovery of cross-flow turbines in paired configuration by means of 3d-CFD and analysis of the streamwise momentum budget
Authors: Zanforlin Stefania , Lupi Paola
Published: October 2021

Literature suggests that cross-flow turbines (CFTs) could be suitable for off-shore wind farms because of the high power-density achievable by shortening the distance between arrays as allowed by a fast wake energy recovery experimentally detectable. By means of 3d-CFD, we analysed the effect of the rotation verse of CFTs in counter-rotating paired configuration on the wake behaviour. Then, we applied the momentum-budget approach to identify the fluid dynamic mechanisms which are more effective in supporting the streamwise momentum recovery. The following results are found. (A) The counter-rotating vortices occurring in the near-wake as a consequence of the vortex shedding at the blade tip are responsible for the vertical advection that enters high momentum flow inside the wake. (B) The turbulent transport contribution is less important, yet it becomes significant starting from the medium wake. (C) For the inner-downwind layout the wake shape appears similar to that of a single turbine, whereas for the inner-upwind layout it is greatly contracted in horizontal direction and enlarged in vertical direction (D). The momentum recovery appears slightly more delayed than in case of a single turbine, yet the velocity deficit appears less extensive for the inner upwind layout that, especially thanks to the wake lateral contraction, could be the preferable in farms consisting in staggered arrays, allowing to shorten the lateral distance between adjacent pairs.
A strategy for the robust forecasting of gas turbine health subjected to fouling
Authors: Aldi Nicola , Casari Nicola , Fadiga Ettore , Friso Riccardo , Oliani Stefano , Pinelli Michele , Spina Pier Ruggero , Suman Alessio , Vulpio Alessandro
Published: October 2021

Fouling represents a major problem for Gas Turbines (GTs) in both heavy-duty and aero-propulsion applications. Solid particles entering the engine can stick to the internal surfaces and form deposits. Components' lifetime and performance can dramatically vary as a consequence of this phenomenon. These effects impact the whole engine in terms of residual life, operating stability, and maintenance costs. In the High-Pressure Turbine (HPT), in particular, the high temperatures soft the particles and promote their adhesion, especially in the short term. Unfortunately, predicting the GT response to this detrimental issue is still an open problem for scientists. Furthermore, the stochastic variations of the components operating conditions increase the uncertainty of the forecasting results. In this work, a strategy to predict the effects of turbine fouling on the whole engine is proposed. A stationary Gas Path Analysis (GPA) has been performed for this scope to predict the GT health parameters. Their alteration as a consequence of fouling has been evaluated by scaling the turbine map. The scaling factor has been found by performing Computational Fluid Dynamic (CFD) simulations of a HPT nozzle with particle injection. Being its operating conditions strongly uncertain, a stochastic analysis has been conducted. The uncertainty sources considered are the circumferential hot core location and the turbulence level at the inlet. The study enables to build of confidence intervals on the GT health parameters predictions and represents a step forward towards a robust forecasting tool.
Evaluation of water washing efficiency and erosion risk in an axial compressor for different water injection conditions
Authors: Agati Giuliano , Di Gruttola Francesca , Gabriele Serena , Simone Domenico , Venturini Paolo , Borello Domenico
Published: October 2021

Gas turbines performance losses are mainly due to the deposition of dirt on the compressor blades that needs to be periodically removed. This is the reason motivating the presence of water washing systems (WWS) in most of the compressor gas turbines. Water washing is generally achieved by installing a number of nozzles on the compressor casing and spraying water that clean the dirty surfaces of the compressor. The side effect of such a technique is the rising risk of erosion due to the impact of water droplets on the compressor blades which is even more pronounced when dealing with online water washing systems that is done while the unit is at normal load. The design of these systems must balance benefits and disadvantages associated to the process itself. The benefits can be measured in terms of water washing efficiency that is a quantity not uniquely defined. In previous works, the authors introduced some indices useful to evaluate the spatial cleaning coverage (the wet to the total surface) and the quantity of water mass actually impacting the dirty surfaces (the impacted to injected mass). On the other hand, water washing erosion is a complex phenomenon depending on several parameters, such as the mechanical properties of the blade material, the impact velocity and angle and the droplet diameter. For this reason, the WWS are strongly influenced by the adopted nozzles and by the injection conditions. The present paper aims at assessing water washing for six different injection conditions in the first stage of a real axial compressor. Two-phase CFD simulations are carried out with Ansys Fluent where a User Defined Function implemented by the authors is used to properly model water droplet erosion mechanism and to obtain all the quantities needed to evaluate the washing quality. Results confirm the strong influence of the injection conditions on the main features of the washing system. The study is part of an ongoing partnership between Baker Hughes and Sapienza University of Rome aiming at maximizing the washing of the compressor blades while maintaining the erosion under specific thresholds.
Failures and Reliability in Hawts Operating in Mountainous Areas, Open Sea and in Harsch Climate Sites
Authors: Maria De Pratti Giovanni
Published: October 2021

Recently, offshore wind plants, as Horn’s Riv one, have reached a remarkable interest and development. In these sites, HAWT’s blades experiment corrosion, erosion and fouling and, at higher latitudes, icing conditions too, as in mountainous areas and in harsch climate sites. The operative conditions may influence the machine damages and they may occur as consequence of erosion, corrosion, fouling, icing, exfoliation caused by the above mentioned environmental conditions. The paper reports about data collection about failures occurred to HAWTS operating in offshore, mountainous and harsch climate sites in last ten years. Particularly, the damage occurred to blades, gears and bearings have been examined and the consequences analysed. The occurred failures are examined and the reliability of WTGs is assessed by appropriate models and analysis. The results are com pared to literature data and they may be very useful in programmable maintenance and in predictable one. Reliability analysis may be also useful to increase energy production.
Assessment of Indoor Environmental Quality in schools by combining survey and modelling: a case study in Albania
Authors: Salamone Francesco , Belussi Lorenzo , Danza Ludovico , Ghellere Matteo , Meroni Italo , Shtylla Arben , Dobjani Etleva , Shtylla Saimir
Published: October 2021

The article describes the outcomes of the monitoring campaign carried out in an educational building nearby Tirana, capital of Albania. Performed under the bilateral agreement between the National Research Council of Italy and the Ministry of Education and Sport of the Republic of Albania, the study proposes a combined approach for the assessment of the IEQ, not limiting only in the collection of objective data through the environmental monitoring of indoor variables but it also includes the subjective perception of indoor environment by the students through the compilation of a specific questionnaire. The classrooms were also modelled using a parametric model combining the functionalities of Honeybee plugin with OpenStudio and Radiance. The results are illustrated by maps of the indoor microclimate and illuminance with spatial resolution of 0.5 meters and one-hour temporal resolution step. Aggregated index and environmental data derived from models are compared to those monitored with nEMoS. This hybrid method overcomes the drawback caused by a low resolution of the monitoring steps and allows the comparison of the objective and subjective perception of the considered environmental factors, as well as the identification of discrepancies in terms of objective evidence and subjective perception related to the considered environmental factors.
Lifetime testing of a flexure based natural gas fired 1 kW thermoacoustic genset
Authors: Steiner Thomas W. , Hoy M. , Antonelli K. B. , Malekian M. , Archibald G. D. S. , Kanemaru T. , Aitchison W. , De Chardon B. , Gottfried K. T. , Elferink M. , Henthorne T. , O’Rourke B. , Kostka P.
Published: October 2021

Etalim has developed and lifetime tested a flexure-based thermoacoustic (TAC) genset operating at high pressure and frequency. It is an efficient and practical 1 kWe genset ready for deployment as a genset or a micro-cogeneration system when integrated with a recuperated natural gas burner and stroke controlling power electronics. It is a maintenancefree, extreme reliability genset particularly suited for remote power applications. The genset is fully costed and designed for manufacturing. Fuel-to-electric efficiency of 22% has been achieved, and one remaining avenue for significant improvement identified. A test TAC has been run for a cumulative time of about 8000 hours to date without any component failures.
Performance analysis of free piston Stirling engine based on the phasor notation method
Authors: Chen Pengfan , Wang Ying , Ding Wenhao , Niu Yafeng , Lin Zibo , Liu Yingwen
Published: October 2021

The free piston Stirling engine (FPSE) is a couple system of dynamics and thermodynamics. Due to the complicated and interactive relationships between the dynamic parameters and thermodynamic parameters, the performance of the FPSE is always difficult to predict and evaluate. The phasor notation method is proposed based on a thermodynamic-dynamic coupled model of a beta-type FPSE in this paper. The output power and efficiency under the different heating temperature and charging pressure are analysed and compared. In addition, based on the Sage numerical model, the influences of heating temperature and charging pressure on the pistons’ displacement amplitudes, power work and efficiency are revealed. This study can provide the assistance for the performance analysis, prediction and optimization of the FPSE.