bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in white matter microstructure and MRI-derived cerebral blood flow after 1-week of exercise training
Authors: Steventon J. J. , Chandler H. L. , Foster C. , Dingsdale H. , Germuska M. , Massey T. , Parker G. , Wise R. G. , Murphy K.
Published: November 2021

Exercise is beneficial for brain health, inducing neuroplasticity and vascular plasticity in the hippocampus, which is possibly mediated by brain-derived neurotrophic factor (BDNF) levels. Here we investigated the short-term effects of exercise, to determine if a 1-week intervention is sufficient to induce brain changes. Fifteen healthy young males completed five supervised exercise training sessions over seven days. This was preceded and followed by a multi-modal magnetic resonance imaging (MRI) scan (diffusion-weighted MRI, perfusion-weighted MRI, dual-calibrated functional MRI) acquired 1 week apart, and blood sampling for BDNF. A diffusion tractography analysis showed, after exercise, a significant reduction relative to baseline in restricted fraction—an axon-specific metric—in the corpus callosum, uncinate fasciculus, and parahippocampal cingulum. A voxel-based approach found an increase in fractional anisotropy and reduction in radial diffusivity symmetrically, in voxels predominantly localised in the corpus callosum. A selective increase in hippocampal blood flow was found following exercise, with no change in vascular reactivity. BDNF levels were not altered. Thus, we demonstrate that 1 week of exercise is sufficient to induce microstructural and vascular brain changes on a group level, independent of BDNF, providing new insight into the temporal dynamics of plasticity, necessary to exploit the therapeutic potential of exercise.
Factors that influence the quality of metabolomics data in in vitro cell toxicity studies: a systematic survey
Authors: Moreno-Torres Marta , García-Llorens Guillem , Moro Erika , Méndez Rebeca , Quintás Guillermo , Castell José Vicente
Published: November 2021

REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) is a global strategy and regulation policy of the EU that aims to improve the protection of human health and the environment through the better and earlier identification of the intrinsic properties of chemical substances. It entered into force on 1st June 2007 (EC 1907/2006). REACH and EU policies plead for the use of robust high-throughput "omic" techniques for the in vitro investigation of the toxicity of chemicals that can provide an estimation of their hazards as well as information regarding the underlying mechanisms of toxicity. In agreement with the 3R’s principles, cultured cells are nowadays widely used for this purpose, where metabolomics can provide a real-time picture of the metabolic effects caused by exposure of cells to xenobiotics, enabling the estimations about their toxicological hazards. High quality and robust metabolomics data sets are essential for precise and accurate hazard predictions. Currently, the acquisition of consistent and representative metabolomic data is hampered by experimental drawbacks that hinder reproducibility and difficult robust hazard interpretation. Using the differentiated human liver HepG2 cells as model system, and incubating with hepatotoxic (acetaminophen and valproic acid) and non-hepatotoxic compounds (citric acid), we evaluated in-depth the impact of several key experimental factors (namely, cell passage, processing day and storage time, and compound treatment) and instrumental factors (batch effect) on the outcome of an UPLC-MS metabolomic analysis data set. Results showed that processing day and storage time had a significant impact on the retrieved cell's metabolome, while the effect of cell passage was minor. Meta-analysis of results from pathway analysis showed that batch effect corrections and quality control (QC) measures are critical to enable consistent and meaningful estimations of the effects caused by compounds on cells. The quantitative analysis of the changes in metabolic pathways upon bioactive compound treatment remained consistent despite the concurrent causes of metabolomic data variation. Thus, upon appropriate data retrieval and correction and by an innovative metabolic pathway analysis, the metabolic alteration predictions remained conclusive despite the acknowledged sources of variability.
Southern Ocean contribution to both steps in deglacial atmospheric CO2 rise
Authors: Ronge Thomas A. , Frische Matthias , Fietzke Jan , Stephens Alyssa L. , Bostock Helen , Tiedemann Ralf
Published: November 2021

The transfer of vast amounts of carbon from a deep oceanic reservoir to the atmosphere is considered to be a dominant driver of the deglacial rise in atmospheric CO2. Paleoceanographic reconstructions reveal evidence for the existence of CO2-rich waters in the mid to deep Southern Ocean. These water masses ventilate to the atmosphere south of the Polar Front, releasing CO2 prior to the formation and subduction of intermediate-waters. Changes in the amount of CO2 in the sea water directly affect the oceanic carbon chemistry system. Here we present B/Ca ratios, a proxy for delta carbonate ion concentrations Δ[CO32−], and stable isotopes (δ13C) from benthic foraminifera from a sediment core bathed in Antarctic Intermediate Water (AAIW), offshore New Zealand in the Southwest Pacific. We find two transient intervals of rising [CO32−] and δ13C that that are consistent with the release of CO2 via the Southern Ocean. These intervals coincide with the two pulses in rising atmospheric CO2 at ~ 17.5–14.3 ka and 12.9–11.1 ka. Our results lend support for the release of sequestered CO2 from the deep ocean to surface and atmospheric reservoirs during the last deglaciation, although further work is required to pin down the detailed carbon transfer pathways.
A multimode metamaterial for a compact and robust dualband wireless power transfer system
Authors: Jiang Xin , Pokharel Ramesh K. , Barakat Adel , Yoshitomi Kuniaki
Published: November 2021

To release more flexibility for users to charge their portable devices, researchers have increasingly developed compact wireless power transfer (WPT) systems in recent years. Also, a dual-band WPT system is proposed to transfer power and signal simultaneously, enriching the system’s functionality. Moreover, a stacked metasurface has recently been proposed for a single band near-field WPT system. In this study, a novel multimode self-resonance-enhanced wideband metasurface is proposed for a robust dual-band WPT system, which significantly improves the performance of both bands. The size of the transmitter (Tx) and the receiver (Rx) are both 15 mm × 15 mm only. The proposed metasurface can improve efficiency from 0.04 up to 39% in the best case. The measured figure of merit (FoM) is 2.09 at 390 MHz and 2.16 at 770 MHz, respectively, in the balanced mode. Especially, the FoM can reach up to 4.34 in the lower mode. Compared to the previous state-of-the-art for similar applications, the WPT performance has significantly been improved.
Cuticle deposition duration in the uterus is correlated with eggshell cuticle quality in White Leghorn laying hens
Authors: Chen Xia , He Zhaoxiang , Li Xingzheng , Song Jianlou , Huang Mingyi , Shi Xuefeng , Li Xianyu , Li Junying , Xu Guiyun , Zheng Jiangxia
Published: November 2021

The cuticle formed in the uterus is the outermost layer as the first defense line of eggshell against microbial invasions in most avian species, and analyzing its genetic regulation and influencing factors are of great importance to egg biosecurity in poultry production worldwide. The current study compared the uterine transcriptome and proteome of laying hens producing eggs with good and poor cuticle quality (GC and PC, the top and tail of the cuticle quality distribution), and identified several genes involved with eggshell cuticle quality (ESCQ). Overall, transcriptomic analysis identified 53 differentially expressed genes (DEGs) between PC versus GC group hens, among which 25 were up-regulated and 28 were down-regulated. No differences were found in the uterine proteome. Several DEGs, including PTGDS, PLCG2, ADM and PRLR related to uterine functions and reproductive hormones, were validated by qPCR analysis. Egg quality measurements between GC and PC hens showed GC hens had longer laying interval between two consecutive ovipositions (25.64 ± 1.23 vs 24.94 ± 1.12 h) and thicker eggshell thickness (352.01 ± 23.04 vs 316.20 ± 30.58 μm) (P < 0.05). Apart from eggshell traits, other egg quality traits didn’t differ. The result demonstrated eggshell and cuticle deposition duration in the uterus is one of the major factors affecting ESCQ in laying hens. PTGDS, PLCG2, ADM and PRLR genes were discovered and might play crucial roles in cuticle deposition by regulating the uterine muscular activities and secretion function. The findings in the present study provide new insights into the genetic regulation of cuticle deposition in laying hens and establish a foundation for further investigations.
Metabolomic credentialing of murine carcinogen-induced urothelial cancer
Authors: Afify Hesham , Ghoneum Alia , Almousa Sameh , Abdulfattah Ammar Yasser , Warren Bailey , Langsten Kendall , Gonzalez Daniela , Casals Randy , Bharadwaj Manish , Kridel Steven , Said Neveen
Published: November 2021

Bladder cancer (BCa) is the most common malignancy of the urinary system with increasing incidence, mortality, and limited treatment options. Therefore, it is imperative to validate preclinical models that faithfully represent BCa cellular, molecular, and metabolic heterogeneity to develop new therapeutics. We performed metabolomic profiling of premalignant and non-muscle invasive bladder cancer (NMIBC) that ensued in the chemical carcinogenesis N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) mouse model. We identified the enriched metabolic signatures that associate with premalignant and NMIBC. We found that enrichment of lipid metabolism is the forerunner of carcinogen-induced premalignant and NMIBC lesions. Cross-species analysis revealed the prognostic value of the enzymes associated with carcinogen-induced enriched metabolic in human disease. To date, this is the first study describing the global metabolomic profiles associated with early premalignant and NMIBC and provide evidence that these metabolomic signatures can be used for prognostication of human disease.
Spin excitations in metallic kagome lattice FeSn and CoSn
Authors: Xie Yaofeng , Chen Lebing , Chen Tong , Wang Qi , Yin Qiangwei , Stewart J. Ross , Stone Matthew B. , Daemen Luke L. , Feng Erxi , Cao Huibo , Lei Hechang , Yin Zhiping , MacDonald Allan H. , Dai Pengcheng
Published: November 2021

In two-dimensional (2D) metallic kagome lattice materials, destructive interference of electronic hopping pathways around the kagome bracket can produce nearly localized electrons, and thus electronic bands that are flat in momentum space. When ferromagnetic order breaks the degeneracy of the electronic bands and splits them into the spin-up majority and spin-down minority electronic bands, quasiparticle excitations between the spin-up and spin-down flat bands should form a narrow localized spin-excitation Stoner continuum coexisting with well-defined spin waves in the long wavelengths. Here we report inelastic neutron scattering studies of spin excitations in 2D metallic kagome lattice antiferromagnetic FeSn and paramagnetic CoSn, where angle resolved photoemission spectroscopy experiments found spin-polarized and nonpolarized flat bands, respectively, below the Fermi level. Our measurements on FeSn and CoSn reveal well-defined spin waves extending above 140 meV and correlated paramagnetic scattering around Γ point below 90 meV, respectively. In addition, we observed non-dispersive excitations at ~170 meV and ~360 meV arising mostly from hydrocarbon scattering of the CYTOP-M used to glue the samples to aluminum holder. Therefore, our results established the evolution of spin excitations in FeSn and CoSn, and identified anomalous flat modes overlooked by the neutron scattering community for many years.
Long-term prognosis and educational determinants of brain network decline in older adult individuals
Authors: Chan Micaela Y. , Han Liang , Carreno Claudia A. , Zhang Ziwei , Rodriguez Rebekah M. , LaRose Megan , Hassenstab Jason , Wig Gagan S.
Published: November 2021

Older adults with lower education are at greater risk for dementia. It is unclear which brain changes lead to these outcomes. Longitudinal imaging-based measures of brain structure and function were examined in adult individuals (baseline age, 45–86 years; two to five visits per participant over 1–9 years). College degree completion differentiates individual-based and neighborhood-based measures of socioeconomic status and disadvantage. Older adults (~65 years and over) without a college degree exhibit a pattern of declining large-scale functional brain network organization (resting-state system segregation) that is less evident in their college-educated peers. Declining brain system segregation predicts impending changes in dementia severity, measured up to 10 years past the last scan date. The prognostic value of brain network change is independent of Alzheimer’s disease (AD)-related genetic risk (APOE status), the presence of AD-associated pathology (cerebrospinal fluid phosphorylated tau, cortical amyloid) and cortical thinning. These results demonstrate that the trajectory of an individual’s brain network organization varies in relation to their educational attainment and, more broadly, is a unique indicator of individual brain health during older age.
Reversible structure transformation between protein nanocages and nanorods controlled by small molecules
Authors: Zhang Xiaorong , Zhang Tuo , Wang Yingjie , Liu Yu , Zang Jiachen , Zhao Guanghua
Published: November 2021

Protein nanocages and nanorods were constructed by using identical building blocks and reversible structure transformation was achieved.
Recent advances in luminescent metal–organic frameworks and their photonic applications
Authors: Li Penghao , Zhou Zhonghao , Zhao Yong Sheng , Yan Yongli
Published: November 2021

In this feature article, we summarise the recent developments in luminescent metal–organic frameworks, including their emission mechanisms and photonic applications ranging from photonic barcodes to miniaturized lasers.
Enzymatic noncovalent synthesis of peptide assemblies generates multimolecular crowding in cells for biomedical applications
Authors: Yi Meihui , Tan Weiyi , Guo Jiaqi , Xu Bing
Published: November 2021

This article highlights the unique features of enzymatic noncovalent synthesis (ENS) for generating multimolecular crowding in cells and the relevant applications for biomedicines.
A new I3O93− group constructed from IO3− and IO55− anion units in Cs3[Ga2O(I3O9)(IO3)4(HIO3)]
Authors: Wang Dandan , Jiang Xiaoqing , Gong Pifu , Zhang Xinyuan , Lin Zheshuai , Hu Zhanggui , Wu Yicheng
Published: November 2021

Cs3[Ga2O(I3O9)(IO3)4(HIO3)] with a novel I3O93− fundamental building block (FBB) constituted by two IO3 and one IO5 polyhedra exhibited a wide band gap.
Electrostatic interactions contribute to the control of intramolecular thiol–disulfide isomerization in a protein
Authors: Maag Denis , Putzu Marina , Gómez-Flores Claudia L. , Gräter Frauke , Elstner Marcus , Kubař Tomáš
Published: November 2021

The roles of structural factors and of electrostatic interactions with the environment on the outcome of thiol–disulfide exchange reactions were investigated in a mutated immunoglobulin domain (I27*) under mechanical stress.
Dissociation of HCl in water nanoclusters: an energy decomposition analysis perspective
Authors: Zech Alexander , Head-Gordon Martin
Published: November 2021

Analysis of the effect of EDA components on the cluster geometry reveals a synergy between the dominant backward-donating (ctb) and forward-donating (ctf) charge-transfer interaction for the destabilization of the HCl bond.
Unprecedented observation and characterization of sulfur-centred bifurcated hydrogen bonds
Authors: Ma Xiantao , Zhu Yingying , Yu Jing , Zhao Geng , Duanmu Jiaxin , Yuan Yiyun , Chang Xue-Ping , Xu Dongli , Zhou Qiuju
Published: November 2021

It is observed that the sulfur atom can unprecedentedly serve as a good acceptor to form the O–H⋯S⋯H–O bifurcated H-bond.
Comparative sustainability assessment of a hydrogen supply network for hydrogen refueling stations in Korea – a techno-economic and lifecycle assessment perspective
Authors: Akhtar Malik Sajawal , Dickson Rofice , Niaz Haider , Hwang Dong Won , Jay Liu J.
Published: November 2021

Economical and environmental sustainability of hydrogen supply routes is evaluated for hydrogen refueling stations.
Automatic and multi-channel detection of bacteria on a slidable centrifugal disc based on FTA card nucleic acid extraction and recombinase aided amplification
Authors: Wang Siyuan , Cai Gaozhe , Duan Hong , Qi Wuzhen , Lin Jianhan
Published: November 2021

This study developed a slidable centrifugal disc for automatic and multi-channel detection of Salmonella using FTA card for DNA extraction and RAA for DNA detection and verified it could detect 10 CFU mL−1 in chicken meat supernatant in 1 h.
Na+ diffusion mechanism and transition metal substitution in tunnel-type manganese-based oxides for Na-ion rechargeable batteries
Authors: Quinzeni Irene , Fujii Kotaro , Bini Marcella , Yashima Masatomo , Tealdi Cristina
Published: November 2021

Structural, computational and electrochemical investigations are combined to study the intercalation properties of tunnel-type Na0.44MnO2 and Cu-substituted Na0.44MnO2.
Medicines for millions of patients
Authors: Rees David C.
Published: November 2021

Three drugs, millions of patients. Sugammadex, erdafitinib, and ribociclib have been used to provide transformative treatments.
Concise synthesis and biological activity evaluation of novel pyrazinyl–aryl urea derivatives against several cancer cell lines, which can especially induce T24 apoptotic and necroptotic cell death
Authors: Chen Jia-Nian , Chen Chu-Ting , He Yue-Zhen , Qin Tai-Sheng , Cheng Li , Sun Ye-Xiang , Yang Kang-Jian , Chen Qi , Yang Chao , Wei Ying
Published: November 2021

Based on structural modification of regorafenib, 28 pyrazinyl–aryl urea derivatives were synthesized and thein vitroanti-cancer effects were evaluated. Compound 5-23 possessed the strongest inhibitory activity against bladder cancer T24 cell line.
Rationally designed foldameric adjuvants enhance antibiotic efficacy via promoting membrane hyperpolarization
Authors: Bhaumik Kaushik Nath , Hetényi Anasztázia , Olajos Gábor , Martins Ana , Spohn Réka , Németh Lukács , Jojart Balázs , Szili Petra , Dunai Anett , Jangir Pramod K. , Daruka Lejla , Földesi Imre , Kata Diána , Pál Csaba , Martinek Tamás A.
Published: November 2021

Antimicrobial foldamers reduce the antibiotic resistance in multi-drug resistant Gram-negative bacteria. They hyperpolarize the membrane at low concentrations by acting as selective ionophores, enhancing the GHK-potential across the membrane.
Enhancing of broadband sound absorption through soft matter
Authors: Ma Fuyin , Wang Chang , Du Yang , Zhu Zicai , Wu Jiu Hui
Published: November 2021

An artificial acoustic soft boundary on the inner wall of an absorber is constructed by an extremely soft PVC gel, and excellent sound absorption enhancement in the broadband frequency range is obtained.
Synthesis of a new 1,3,4-thiadiazole-substituted phenanthroimidazole derivative, its growth on glass/ITO as a thin film and analysis of some surface and optoelectronic properties
Authors: Zurnacı Merve , Ünal Fatih , Demir Serkan , Gür Mahmut , Şener Nesrin , Şener İzzet
Published: November 2021

A novel phenanthroimidazole derivative with p-type conductivity was prepared and fabricated as a heterostructure, exhibiting a negative differential resistance and photodiode properties.
Tuning of spin-crossover behavior in two cyano-bridged mixed-valence FeIII2FeIItrinuclear complexes based on a TpRligand
Authors: Sulaiman Arshia , Jiang Yi-Zhan , Javed Mohammad Khurram , Wu Shu-Qi , Li Zhao-Yang , Bu Xian-He
Published: November 2021

With the use of TpRderivatives, we have demonstrated the modulation in the SCO behavior in two analogous trinuclear complexes. Moreover, a change in the spin transition temperatureviasolvent loss is observed.
In situ phosphonium-containing Lewis base-catalyzed 1,6-cyanation reaction: a facile way to obtain α-diaryl and α-triaryl acetonitriles
Authors: Tan Jian-Ping , Chen Yuan , Ren Xiaoyu , Guo Yumeng , Yi Bing , Zhang Hongkui , Gao Guowei , Wang Tianli
Published: November 2021

A in situ phosphonium-containing catalyst and its successful application in promoting remote 1,6-cyanation reaction of p-QMs and fuchsones have been disclosed, providing a facile and direct access to both α-diaryl and α-triaryl acetonitriles.
Dual functional sp2 carbon-conjugated covalent organic frameworks for fluorescence sensing and effective removal and recovery of Pd2+ ions
Authors: Yue Jie-Yu , Ding Xiu-Li , Wang Yu-Tong , Wen Yang-Xin , Yang Peng , Ma Yu , Tang Bo
Published: November 2021

The effective detection and simultaneous removal of Pd2+ is beneficial to environmental protection as well as human health, and owing to its high consumption and cost, the recovery of Pd2+ is important to ensure sustainability.
Recent progress of inert anodes for carbon-free aluminium electrolysis: a review and outlook
Authors: He Yong , Zhou Ke-chao , Zhang Yan , Xiong Hui-wen , Zhang Lei
Published: November 2021

This review introduces the latest research progress of inert anodes for aluminium electrolysis and compares the comprehensive performances of different kinds of materials, including metals, ceramics and cermets.
Do Flexible Silicone Tubes Immersed in Water Combined With Vocalise Improve the Immediate Effect on Voice?
Authors: Cardoso Nathália Suellen Valeriano , Lucena Jonia Alves , de Lira Zulina Souza , de Vasconcelos Silvio José , Lopes Leonardo Wanderley , Gomes Adriana de Oliveira Camargo
Published: November 2021

Purpose:

This study aimed to analyze the immediate effect on a singer's voice of a flexible silicone tube immersed in water combined with ascending and descending vocalise scales compared with ascending and descending vocalise scales alone.

Method:

A pre- and post-intervention quasi-experimental study was conducted. Thirty adult singers between 18 and 45 years old with no laryngeal disorders performed the two techniques for 3 min each on different days. Acoustic measurements of frequency, jitter, shimmer, glottal-to-noise excitation ratio, noise, smoothed cepstral peak prominence (CPPS), maximum phonation time (MPT), voice range profile, and self-perceived vocal effort (Borg Category Ratio 10-BR Scale adapted for vocal effort) were assessed before and after performing the techniques.

Results:

The results indicated an increase in singers' CPPS and MPT values and a decrease in shimmer and noise when performing with a flexible silicone tube immersed in water combined with vocalise. The singers reported a perception of decreased vocal effort after both methods. However, the diminished perceived vocal effort became more pronounced with the tube phonation technique combined with vocalise.

Conclusions:

Phonation in tubes combined with vocalise improved the vocal acoustic parameters (including cepstral measurements), increased MPT, and diminished perceived vocal effort. Although using vocalise alone diminished perceived vocal effort, this decrease was more pronounced in the tube phonation technique combined with vocalise.
Grammatical Verb Errors: Differences Between English Learners With and Without Diagnosed Language-Based Learning Disabilities
Authors: Fumero Keisey , Wood Carla
Published: November 2021

Purpose:

This study examines the written language samples of fifth grade English learner (EL) students with and without diagnosed language-based learning disabilities (LLDs) in an effort to explore the utility of such supplemental materials for aiding in differential diagnosis of ELs with and without LLDs.

Method:

This sample of 127 fifth grade students consisted of ELs without identified disabilities (
n
= 89) and ELs diagnosed with LLDs (
n
= 38). Written language samples from a classroom-based expository writing task were coded for grammaticality and specific verb type of errors. An analysis of variance (ANOVA) between the groups that differed by language abilities was conducted at two time points to compare the frequency of errors and the average change in grammaticality from the beginning of the school year to the end of the school year.

Results:

EL students with and without LLDs performed similarly at the beginning of the school year. ELs without LLDs showed greater average change in accuracy across the school year. Significantly, higher proportions of verb tense and verb omission errors were demonstrated by ELs with LLDs when compared with their EL peers at the end of the school year. Overall grammatical accuracy was also lower for ELs with LLDs.

Conclusions:

Group differences at the end of the school year were confirmed in types and rate of verb errors. Results support the potential clinical utility of monitoring verb errors in writing samples over time as a supplemental tool in diagnostic evaluations and assessments for progress monitoring.
Ecosystem services and disservices associated with pastoral systems from Patagonia, Argentina – A review
Authors: Tittonell Pablo , Hara Sofía M. , Álvarez Valeria E. , Aramayo Valeria M. , Bruzzone Octavio A. , Easdale Marcos H. , Enriquez Andrea S. , Laborda Luciana , Trinco Fabio D. , Villagra Sebastián E. , El Mujtar Verónica
Published: November 2021

Pastoral systems worldwide secure rural livelihoods in the harshest environments on Earth. Their low productivity per area unit or head makes them the subject of much criticism with regard to their environmental impact, particularly in relation to global warming, desertification and land degradation. Such is the case of the traditional pastoral systems of Patagonia, a vast and isolated region where sedentary and mobile pastoralism coexist and contribute to shape landscapes and cultures. We argue that pastoral systems provide a wide range of ecosystem services that may compensate for their negative impact on the environment. We review the scarcely available evidence from Patagonia to identify ecosystem services and disservices associated with pastoralism, and pay special attention to the carbon balance: with C footprints between 10 to 40 kg CO2-eq.kg−1 carcass, pastoral systems in dry Patagonia are below or within the range of semi-extensive livestock systems worldwide (35–45 CO2-eq. kg−1 carcass). To inform development and policy, the assessment of trade-offs and synergies between ecosystem services needs to incorporate the intertwined social and ecological dynamics of complex pastoral systems, along resource regenerative trajectories.
Services écosystémiques et riziculture autour du lac de Tonle Sap, Cambodge
Authors: Neang Malyne , Méral Philippe
Published: November 2021

Cet article vise à analyser les services (et dis-services) écosystémiques que la population cambodgienne retire de l’écosystème formé par le lac Tonle Sap et sa grande plaine d’inondation. Caractérisé par un phénomène de flux et de reflux du fleuve Mékong selon la saison des pluies, ce lac, dont la taille varie de un à cinq, est le lieu de la culture du riz, principale activité agricole du pays et denrée alimentaire de sa population. L’étude de cet agroécosystème, réalisé par des enquêtes dans six villages, montre une complexité dans la compréhension de ces services écosystémiques. Certains sont positifs, d’autres négatifs. Certains sont positifs jusqu’à un certain niveau, mais deviennent négatifs par la suite. Certains sont coproduits par la riziculture, qui au fil du temps a façonné l’écosystème. Nous montrons également, à partir d’une analyse des systèmes agraires, que les systèmes de production sont plus ou moins compatibles avec le maintien de ces services.
Numerical analysis of pulverized biomass combustion
Authors: Deniz Canal Cansu , Böke Erhan , Benim Ali Cemal
Published: November 2021

Combustion of pulverized biomass in a laboratory swirl burner is computationally investigated. The two-phase flow is modelled by an Eulerian-Lagrangian approach. The particle size distribution and turbulent particle dispersion are considered. The radiative heat transfer is modelled by the P1 method. For modelling turbulence, different RANS modelling approaches are applied. The pyrolysis of the solid fuel is modelled by a single step mechanism. For the combustion of the volatiles a two-step reaction mechanism is applied. The gas-phase conversion rate is modelled by the Eddy Dissipation Model, combined with kinetics control. The results are compared with measurements.
Modeling of chemical composition in the melt pool during laser welding of Aluminum / Magnesium alloys
Authors: Ben Halim Sabrine , kriaa Wassim , Autric Michel
Published: November 2021

Joining dissimilar metals is very difficult due to the formation of brittle intermetallic phases which may be detrimental to mechanical properties. The present work aims to investigate the transport phenomenon in the weld bead and to understand the materials mixing during laser welding process of dissimilar Aluminum-Magnesium alloys. A three-dimensional transient model based on fluid flow, heat and mass transfer has been developed to predict the formation of the weld and to study numerically and experimentally the diffusion of alloying elements in the melted zone. SEM analysis of chemical composition has been realized to map elements distribution in the melted zone. The results of simulation show the formation of a heterogeneous mixture in the melt pool. The elements distribution map and the presence of brittle intermetallic phases in the fusion zone were analysed. The formation of intermetallic compounds, comprising Al3Mg2 and Al12Mg17 phases were predicted by studying the chemical elements distribution in the weld pool. A good tendency between experimental and numerical results is noticed for the weld.
Lattice Boltzmann simulation of liquid falling on horizontal rectangular pillar arrays
Authors: Sugimoto Makoto , Miyazaki Tatsuya , Li Zelin , Kaneda Masayuki , Suga Kazuhiko
Published: November 2021

Stator coils of automobiles in operation generate heat and are cooled by a coolant poured from above. Since the behavior characteristic of the coolant poured on the coils is not clarified yet due to its complexity, the three-dimensional two-phase flow simulation is conducted. In this study, as a steppingstone to the simulation of the liquid falling on the actual coils, the coils are modelled with horizontal rectangular pillar arrays whose governing parameters can be easily changed. The two-phase flows are simulated using the lattice Boltzmann method and the phase-field model, and the effects of the governing parameters, such as the physical properties of the cooling liquid, the wettability, and the gap between the pillars, on the wetting area are investigated. The results show that the oil tends to spread across the pillars because of its high viscosity. Moreover, the liquid spreads quickly when the contact angle is small. In the case that the pillars are stacked, the wetting area of the inner pillars is larger than that of the exposed pillars.
Numerical Assesment of a Small-Scale and Very Low Tip Speed Ratio Wind Turbine
Authors: Bourhis Martin , Pereira Michaël , Ravelet Florent , Dobrev Ivan
Published: November 2021

The aim of this paper is to study by CFD the performance and to characterize the velocity fields in the wake of an horizontal axis wind turbine. The design of this wind turbine is far from classical as it has been designed to work at very low angular velocity to promote torque. The 8 blades are not isolated but form a high solidity blade cascade. The numerical simulation compares well to experimental data regarding the power coefficients. The analysis of the wake does show that high tangential velocities, close to the order of magnitude that was used as a design requirement, are generated and form a stable rotating wake. This rotating kinetic energy in the wake may be used to rotate a second rotor in a counter-rotating arrangment.
Impact of Integrating Solar Technique On Buildings'thermal Comfort and Energy Consumption: A Numerical Study
Authors: Ben Romdhane Sahar , Younsi Zohir , Naji Hassan , Mahjoub Said Nejla , Jemni Abdelmajid
Published: November 2021

In the context of shrinking non-renewable energy resources and reducing greenhouse gas emissions, it turns out necessary to drop energy consumption and move towards renewable energy sources. In this regard, solar energy being an abundant source of energy, it can play an important role in the building energy supply. This energy supplement can come from passive solar technologies, of which the Trombe wall is one of the passive models most used in the building envelope, whose main role is to ensure net gains. Thereby, the main aim of this study is to highlight the use of a simple method to reduce the buildings heating demand. For this, a 3-D model was developed through scSTREAM V2020 software to investigate the thermal performance of a classical Trombe wall in winter while targeting desirable indoor thermal comfort conditions. In addition, studies have been performed to optimize the energy consumption It turned out that, in the presence (respectively absence) of solar irradiation, the Trombe wall acts as a solar absorber (respectively a heat source).
Modeling dynamics of pressure fluctuations in a microchannel heat exchanger covered with a wire mesh membrane
Authors: Czarnecki Jerry , Mosdorf Romuald , Grzybowski Hubert , Dzienis Paweł
Published: November 2021

Pressure and mass flow fluctuations in a system consisting of a microchannel two-phase heat exchanger with wire mesh covering and overflow chamber were modelled by employing mass, momentum, and energy balances on the fluid in mesh volume. These fluctuations are a result of the alternate wetting and drying of the mesh membrane driven by a combination of evaporation and capillary pressure-driven flow into the mesh. Experiments using a system of eleven parallel microchannels, each of dimension 32 x 0.25 x 0.5 mm, slotted into a copper substrate and covered with a stainless steel mesh of 0.025 mm wire and 0.026 mm aperture, confirm the occurrence of these high frequency pressure and mass flow fluctuations. The use of non-linear methods that included attractor reconstruction and recurrence plotting to enhance predictive capabilities is also explored.
Development of a Virtual Metering System Application for High Water Cut Wells with Electric Submersible Pumps (ESPS) – a Case Study for Quifa Field
Authors: Asuaje Miguel , Zapata Julieth , Arcos Wilmer
Published: November 2021

Well surveillance is a mandatory requirement for reservoir characterization and production optimization that every asset must aim for. To guarantee constant monitoring of a single well, installing conventional multi-phases flow meters systems is necessary. As an alternative way, this paper presents a Virtual Metering System (VMS) developed to estimate flow rates in oil wells with high water cut operating with electric submersible pumps as artificial lift systems. The VMS starts from a mathematical model based on production variables, well data, and pump performance curves to estimate fluids flow rates and water cut using a Newton Raphson Multivariate Method. The VMS was implemented in 11 wells in Quifa Field, Colombia. The VMS is constantly feeding by data from the PI System. The VMS results show a deviation of less than 3% in calculating the fluid flow rate and less than 5% in estimating the water cut.
Optimization of Air-cooling System for a Lithium-ion Battery Pack
Authors: Jin Sungwook , Youn Min-Sik , Kim Youn-Jea
Published: November 2021

Lithium-ion batteries have been used as energy storage technologies for electric vehicles or power plants due to their high energy density, low self-discharge rate, and long lifespan. Since the temperature of the batteries are directly related with their durability, distributing the temperature uniformly and efficiently is critically important. In this study, a technology using forced convection with air was implemented to remove heat of the battery cells inside a package. The performance of the cooling system was evaluated by changing the gap distance between the battery cells and the configurations of the air channel. In order to improve the cooling performance of the battery, the shape of the battery module was optimized. To begin the optimization process, a sensitivity analysis was conducted to analyze the influence of the design parameters on the battery performance. Based on the result from the analysis, an optimization process was performed to determine an optimum channel design. As a result of the optimization, a battery cell package with the lowest maximum temperature and a minimum deviation between the temperature in between each cell was selected.
Behaviour of hydrodynamic journal bearing under the combined influence of textured surface and Non-Newtonian Rabinowitsch
fluid model
Authors: Manser Belkacem , Khelladi Sofiane , Deligant Michael , Ragueb Haroun , Belaidi Idir , Bakir Farid
Published: November 2021

In the present study, the static characteristics of hydrodynamic circular journal bearings of finite length are highlighted, using the combined influences of textured surface and non-Newtonian lubricants behavior, obeying to the Rabinowitsch fluid model. The associated nonlinear Rabinowitsch-Reynolds equation has been discretized using finite differences scheme and solved by the mean of Elrod’s algorithm taking into account the presence of cylindrical textures on full/optimum bearing surface. Following to the absence of textures on the bearing surface or the non-Newtonian fluid behavior, the obtained results are in good agreement with the reference ones. The hydrodynamic lubrication static performances are computed for various parameters such as textures location; eccentricity ratio and the rheological coeffcient. The results suggest that texturing the bearing’s convergent zone enhances significantly the load carrying capacity and reduces the friction coeffcient, whereas texturing the full bearing surface may leads to bad performances. It is also noticed that the pseudoplastic lubricant coeffcient decreases the bearing performances (load capacity and pressure) compared to Newtonian fluid cases. Considering the optimal arrangement of textures on the contact surface, a significant improvement in terms of load capacity and friction can be achieved, especially at low pseudoplasticity effect.
Numerical study of shear-based hemolysis in aorta with left ventricular assistance device
Authors: Song Jianfei , Marcel Louis , Specklin Mathieu , Kouidri Smaine
Published: November 2021

Ventricular assistance devices (VADs) for heart failure treatment have been paid high attention among researchers for decades. However, the follow-up complications such as hemolysis and thrombosis require further optimization for this technique. Shear stress has been demonstrated to be significantly related to the hemolysis because of the rupture of red blood cells membrane with a leaking of hemoglobin in the plasma. This issue has already been investigated inside the pump of VAD, but estimations are still lacking regarding hemolysis generation in the aorta itself after VAD implantaion. Thus, the present study aims to evaluate the hemolysis in aorta through establishing the 3D numerical model of aorta with left ventricular assistance device (LVAD). Non-Newtonian Carreau model has been adopted. Comparisons of hemolysis evaluation have been made with two different mathematical models existing in literature. Moreover, the flow topology and hemodynamic variations have been studied. Different working conditions of LVAD have been considered corresponding to different heart failure severities. The results reveal a relatively low level of hemolysis risks in aorta. The thrombosis is more prone to occur in the case of severe heart failure condition.
Numerical prediction of drug release from polyurethane samples combining kinetic model developed by experimental data
Authors: Song Jianfei , Abbasnezhad Navideh , Specklin Mathieu , Shirinbayan Mohammadali , Kouidri Smaine , Bakir Farid
Published: November 2021

With the aim of optimizing Drug Eluting Stents (DES), particular attention has been laid on computational methods of controlling the drug release profile among researchers. Consequently, various models and simulations are available in the literature. Nevertheless, validations based on biorelevant
in-vitro trials are lacking. In the present study, a comparison of drug release from polyurethane samples between calculated results and experimental-data has been carried out. The calculation results are from a numerical simulation and a newly established mathematical model for reproducing the liberation kinetic. Different fluid flow rates and initial drug concentrations in polymer have been taken into account.
Mathematical modeling and numerical investigation of density wave instability of supercritical natural circulation loop
Authors: Rai Santosh Kumar , Ahlawat Neha , Kumar Pardeep , Panwar Vinay
Published: November 2021

In present paper, a mathematical model based on the one dimensional nonlinear mass, momentum and energy conservation equations has been developed to study the density wave instability (DWI) in horizontal heater and horizontal cooler supercritical water natural circulation loop (HHHC-SCWNCL). The one dimensional nonlinear mass, momentum and energy conservation equations are discretized by using finite difference method (FDM). The numerical model is validated with the benchmark results (NOLSTA model). Numerical simulations are performed to find the threshold stability zone (TSZ) and draw the stability map for natural circulation loop. Further, effect of change in diameter and riser height on the density wave instability of SCWNCL has been investigated.
Assessment of a mathematical model considering the effect of flow rate on in-vitro drug-release from PLGA films
Authors: Abbasnezhad Navideh , Bakir Farid , Champmartin Stéphane , Shirinbayan Mohammadali
Published: November 2021

Drug-eluting stents implanted in blood vessels are subject to various dynamics of blood flow. In this study, we present the evaluation of a mathematical model considering the effect of flow rate, to simulate the kinetic profiles of drug release (Diclofenac Sodium (DS)) from in-vitro from PLGA films. This model solves a set of non-linear equation for modeling simultaneously the burst, diffusion, swelling and erosion involved in the mechanisms of liberation. The release parameters depending on the flow rate are determined using the corresponding mathematical equations. For the evaluation of the proposed model, test data obtained in our laboratory are used. To quantify DS release from drug-carrier PLGA films, we used the flow-through cell apparatus in a closed-loop. Four flow rate values are applied. For each value, the model-substance liberation kinetics showed an increase in drug released with the flow rate. The simulated release profiles show good agreement with the experimental results. Therefore, the use of this model could provide a practical tool to assess in-vitro drug release profiles from polymer matrices under continuous flow rate constraint, and could help improve the design of drug eluting stents.
Modeling the Evaporation of Drying Sessile Droplets with Buoyancy Driven Internal Convection
Authors: Akdag Osman , Akkus Yigit , Çetin Barbaros , Dursunkaya Zafer
Published: November 2021

Droplet evaporation is a fundamental phenomenon encountered in diverse applications such as inkjet printing, DNA mapping, film coating, and electronics cooling. Modeling the evaporation process of a sessile droplet is complicated because of the coupling of several physical phenomena occurring in different phases and various magnitudes such as the buoyant convection of the liquid in millimeter size droplets and that of the surrounding air/water vapor mixture, in the order of meters. In this study, the theoretical framework presented previously for the steadily fed droplets [Int J Therm Sci, 158 (2020) 106529] is extended to resolve the evaporation of drying droplets with a pinned contact line. Based on the quasi-steady-state assumption, buoyant convection inside the droplet and diffusive-convective transport of vapor in the gas domain are modeled. As a test case, drying process of a water droplet with a 68° initial contact angle on a heated substrate is simulated and the predictions of the model are interpreted.
Numerical modeling of a flat air solar collector fitted with obstacles
Authors: Amraoui Mohammed Amine , Benosman Fayssal
Published: November 2021

The weakness of the solution of flat-air solar collectors in the absence of a turbulence promoter has led researchers to seek other means to improve the performance of the collector. to improve the heat exchange in the air stream from the flat solar collector to the air is the creation of baffles or obstacles to give the longest possible flow path and create a large possible turbulence network. In this article, we studied an air flow around an obstacle field in a flat air solar collector, using the Ansys CFX calculator software, we make a digital 3 D similarity and we give results on the heat exchange in the flat air solar collector and the aim of this study is to show the effect of the obstacles for the fluid flow and the heat transfer in the fluid flow of the flat air solar collector.
Analysis of heat exchanger in an air handling unit – A case study
Authors: Borowski Marek , Zwolińska Klaudia , Czerwiński Marcin
Published: November 2021

Ventilation plays an important role in providing comfortable conditions for users and is also one of the most energy-consuming systems in the building. Due to successive regulations aimed at reducing the energy load of buildings towards zero-energy buildings, energy recovery systems in air handling units have become an indispensable element. The high effectiveness of the entire system guarantees a reduction in energy demand. At very low or very high external temperatures, appropriate comfort conditions are provided by additional heaters or coolers. The subject of the paper is a ventilation system in a hotel located in southern Poland. The building is a faithful reconstruction of the historical saltworks adapted for the needs of the hotel. The air handling unit equipped with a rotary exchanger supplies air to hotel rooms located on two floors. The analysis includes the effectiveness of the air-handling unit operation under various external conditions, as well as the temperature changes during heat exchange. The results show the actual operation of the air-handling unit, which is particularly important in terms of reducing the energy consumption of the hotel.
Aquatic physical and chemical characteristics of reservation and prohibited areas of mahseer (Tor douronensisValenciennes, 1842) in Muara Bungo and Kerinci Regencies, Jambi Province of Indonesia
Authors: Safitri Febri Ria , Sulistiono  , Hariyadi Sigid
Published: November 2021

Masheer (Tor douronensis) is one of the important commodities, has long been known as one of the fish with a high enough value, and is loved by many people in Jambi Province and several other provinces in Indonesia. However, the ecological information of this fish is not widely known. This study examines the characteristics of aquatic physical and chemical of the reserved and prohibited area for fish in Muara Bungo and Kerinci Regencies in Jambi Province. The study was carried out from December 2018 to October 2019 at four locations, i.e., Lubuk Alai, Senamat River, and Tarutung Village, and the river outside the protected area. Aquatic physical and chemical parameters data were collected in-situ and ex-situ. The Aquatic parameters observed were temperature 25.7-30.1oC, pH 6-7, DO 5.3-7.8, transparency 15-125 cm, depth 25-207 cm, turbidity 1.4-158.3 ppm, TSS 3.0-62.9 ppm, ammonia 0.08-0.76 ppm, nitrite 0.03-0.31 ppm, nitrate 0.00-0.68 ppm, and total phosphate 0.00-1.31 ppm, which were suitable for aquatic life. Based on habitat condition grouping, Lubuk Alai and Tarutung Village tend to have a higher similarity, which ammonia, transparency, depth, and total phosphate were the main components.