bluuebunny/crossref_metadata_2025 huggingface dataset:
A microfluidic-integrated lateral flow recombinase polymerase amplification (MI-IF-RPA) assay for rapid COVID-19 detection
Authors: Liu Dan , Shen Haicong , Zhang Yuqian , Shen Danyu , Zhu Mingyang , Song Yanling , Zhu Zhi , Yang Chaoyong
Published: March 2021

A simple microfluidic-integrated lateral flow recombinase polymerase amplification (MI-IF-RPA) assay was developed for rapid COVID-19 detection.
Mechanism of magnetization reduction in iron oxide nanoparticles
Authors: Köhler Tobias , Feoktystov Artem , Petracic Oleg , Kentzinger Emmanuel , Bhatnagar-Schöffmann Tanvi , Feygenson Mikhail , Nandakumaran Nileena , Landers Joachim , Wende Heiko , Cervellino Antonio , Rücker Ulrich , Kovács András , Dunin-Borkowski Rafal E. , Brückel Thomas
Published: March 2021

Antiphase boundaries in iron oxide nanoparticles with oleic acid coating were found to be a major contributor to the observed reduction in saturation magnetization.
Studies on chemoselective synthesis of 1,4- and 1,2-dihydropyridine derivatives by a Hantzsch-like reaction: a combined experimental and DFT study
Authors: Li Peng , Wang Shijie , Tian Nana , Yan Hong , Wang Juan , Song Xiuqing
Published: March 2021

In the experimental process of preparing 1,4-DHP by a Hantzsch-like reaction, it was found that a by-product named 1,2-DHP was produced.
Understanding the mechanism of the chiral phosphoric acid-catalyzed aza-Cope rearrangement
Authors: Falcone Bruno N. , Grayson Matthew N.
Published: March 2021

Using Density Functional Theory, the mechanism of the enantioselective phosphoric acid-catalyzed aza-Cope rearrangement was investigated. Stabilization of the preferred reaction pathway was rationalized by studying the non-bonding interactions between substrate and catalyst.
The effect of Cu dopants on electron transfer to O2 and the connection with acetone photocatalytic oxidations over nano-TiO2
Authors: Liu Baoshun , Wang Jiangyan , Parkin Ivan P. , Zhao Xiujian
Published: March 2021

Correlation between the electron transfer through Cu dopants and the effect on photocatalytic effect was revealed.
Bond switching is responsible for nanoductility in zeolitic imidazolate framework glasses
Authors: To Theany , Sørensen Søren S. , Yue Yuanzheng , Smedskjaer Morten M.
Published: March 2021

The fracture mechanism of zeolitic imidazolate framework (ZIF) glasses is revealed to be associated with bond switching of organic linkers around central Zn nodes. The bond switching is more pronounced for ZIF glasses with smaller organic linkers.
About the importance of purge time in molecular layer deposition of alucone films
Authors: Jain Hardik , Poodt Paul
Published: March 2021

In MLD of alucone using trimethylaluminum (TMA) and ethylene glycol (EG), TMA is known to infiltrate into the MLD film taking very long to outgas. An insufficient purge can then lead to an additional CVD component in the overall growth.
A hybrid bulk-heterojunction photoanode for direct solar-to-chemical conversion
Authors: Yao Liang , Liu Yongpeng , Cho Han-Hee , Xia Meng , Sekar Arvindh , Primera Darwich Barbara , Wells Rebekah A. , Yum Jun-Ho , Ren Dan , Grätzel Michael , Guijarro Néstor , Sivula Kevin
Published: March 2021

The development of efficient and stable organic semiconductor-based photoanodes for solar fuel production is advanced by using a robustin situ-formed covalent polymer network together with a mesoporous inorganic film in a hybrid bulk heterojunction.
Improving the photocatalytic H2 evolution activity of Keggin polyoxometalates anchoring copper-azole complexes
Authors: Shen Qingbo , Gómez-García Carlos J. , Sun Wenlong , Lai Xiaoyong , Pang Haijun , Ma Huiyuan
Published: March 2021

Two new polyoxometalate (POM)-based materials with a maximum photocatalytic H2 evolution rate of 3813 μmol g−1 h−1, show promising results for new-generation noble metal-free photocatalysts.
A novel high efficiency polar photocatalyst, Zn(IO3)2: synthesis, crystal structure and photocatalytic activity
Authors: Zhao Wenwu , Liu Jinqiang , Wang Xiuwen , Huang Yan , Zhou Haijing , Yu Jianyuan , Liu Jian , Hao Bin , Wang Xiaoliu , Li Yingna
Published: March 2021

For Zn(IO3)2, there is an internal polarization electric field along the positive b-axis. Under the action of polarization electric field, the photogenerated carriers will quickly migrate to the surface, thus improving the photocatalytic efficiency.
Ultrasensitive determination of chloramphenicol in pork and chicken meat samples using a portable electrochemical sensor: effects of 2D nanomaterials on the sensing performance and stability
Authors: Dinh Ngo Xuan , Pham Tuyet Nhung , Huy Tran Quang , Trung Do Quang , Tuan Pham Anh , Khue Vu Quang , Van Quy Nguyen , Le Van Phan , Lam Vu Dinh , Le Anh-Tuan
Published: March 2021

This work contributes to a deeper understanding of the effects of functional 2D nanomaterials on the electrochemical sensing performance of SPE-based portable sensors for the rapid, accurate, and on-site determination of CAP in food samples.
Cobalt-based metal–organic frameworks for the photocatalytic reduction of carbon dioxide
Authors: Zhang Wanxia , Huang Ruting , Song Liyan , Shi Xianyang
Published: March 2021

Metal–organic frameworks (MOFs) are porous materials composed of metal centers and organic connectors.
Lewis acid mediated cyclization: synthesis of 2 spirocyclohexylindolines
Authors: Kong Xiang-Kai , Xiong Zhi-Min , Zhi Xiang , Meng Xue-Ling , Zhao Jing-Feng , Chen Wen , Zhang Hongbin
Published: March 2021

Herein, we report the synthesis of 2-spirocyclohexylindolines based on a Lewis acid mediated cyclization.
Towards a unified understanding of the copper sites in particulate methane monooxygenase: an X-ray absorption spectroscopic investigation
Authors: Cutsail George E. , Ross Matthew O. , Rosenzweig Amy C. , DeBeer Serena
Published: March 2021

Extended X-ray absorption fine structure spectroscopic analysis of particulate methane monooxygenase reveals only monocopper sites and investigates the possible origins of the previous observed dicopper signals.
A review of smartphones‐based indoor positioning: Challenges and applications
Authors: Nguyen Khuong An , Luo Zhiyuan , Li Guang , Watkins Chris
Published: March 2021

The continual proliferation of mobile devices has encouraged much effort in using the smartphones for indoor positioning. This article is dedicated to review the most recent and interesting smartphones‐based indoor navigation systems, ranging from electromagnetic to inertia to visible light ones, with an emphasis on their unique challenges and potential real‐world applications. A taxonomy of smartphone sensors will be introduced, which serves as the basis to categorise different positioning systems for reviewing. A set of criteria to be used for the evaluation purpose will be devised. For each sensor category, the most recent, interesting, and practical systems will be examined, with detailed discussion on the open research questions for the academics, and the practicality for the potential clients.
A regression approach to zebra crossing detection based on convolutional neural networks
Authors: Wu Xue‐Hua , Hu Renjie , Bao Yu‐Qing
Published: March 2021

Zebra crossing detection is a fundamental function of the electronic travel aid. It can locate the zebra crossing and estimate its direction to help the visually impaired to cross the road safely. In contrast to the conventional methods, a regression approach is adopted to detect zebra crossing based on convolutional neural networks. Specifically, a fixed‐size window slides across the image captured at the intersection. The image patches are sequentially fed to the logistic regression model to identify the zebra crossing. Then the image patch of zebra crossing is fed to the regression model to predict the direction. The parameters of models are optimized by the backpropagation algorithm before predictions. Compared with existing methods, the proposed method can improve the precision‐recall performance of the zebra crossing identification and reduce the root mean square error of predicted directions.
Shock-heated radiation-driven outflows as a solution to the weak-wind problem of late O-type stars
Authors: Lagae C. , Driessen F. A. , Hennicker L. , Kee N. D. , Sundqvist J. O.
Published: March 2021

Context. Radiation-driven mass loss is key to our understanding of massive-star evolution. However, for low-luminosity O-type stars there are big discrepancies between theoretically predicted and empirically derived mass-loss rates (called the weak-wind problem).

Aims. We compute radiation-line-driven wind models of a typical weak-wind star to determine its temperature structure and the corresponding impact on ultra-violet (UV) line formation.

Methods. We carried out hydrodynamic simulations of the line-deshadowing instability (LDI) for a weak-wind star in the Galaxy. Subsequently, we used this LDI model as input in a short-characteristics radiative transfer code to compute synthetic UV line profiles.

Results. We find that the line-driven weak wind is significantly shock heated to high temperatures and is unable to cool down efficiently. This results in a complex temperature structure where more than half of the wind volume has temperatures significantly higher than the stellar effective temperature. Therefore, a substantial portion of the weak wind will be more ionised, resulting in a reduction of the UV line opacity and therefore in weaker line profiles for a given mass-loss rate. Quantifying this, we find that weak-wind mass-loss rates derived from unsaturated UV lines could be underestimated by a factor of between 10 and 100 if the high-temperature gas is not properly taken into account in the spectroscopic analysis. This offers a tentative basic explanation for the weak-wind problem: line-driven weak winds are not really weaker than theoretically expected, but rather a large portion of their wind volume is much hotter than the stellar effective temperature.
Evidence for differentiation of the most primitive small bodies
Authors: Carry B. , Vernazza P. , Vachier F. , Neveu M. , Berthier J. , Hanuš J. , Ferrais M. , Jorda L. , Marsset M. , Viikinkoski M. , Bartczak P. , Behrend R. , Benkhaldoun Z. , Birlan M. , Castillo-Rogez J. , Cipriani F. , Colas F. , Drouard A. , Dudziński G. P. , Desmars J. , Dumas C. , Ďurech J. , Fetick R. , Fusco T. , Grice J. , Jehin E. , Kaasalainen M. , Kryszczynska A. , Lamy P. , Marchis F. , Marciniak A. , Michalowski T. , Michel P. , Pajuelo M. , Podlewska-Gaca E. , Rambaux N. , Santana-Ros T. , Storrs A. , Tanga P. , Vigan A. , Warner B. , Wieczorek M. , Witasse O. , Yang B.
Published: March 2021

Context. Dynamical models of Solar System evolution have suggested that the so-called P- and D-type volatile-rich asteroids formed in the outer Solar System beyond Neptune’s orbit and may be genetically related to the Jupiter Trojans, comets, and small Kuiper belt objects (KBOs). Indeed, the spectral properties of P- and D-type asteroids resemble that of anhydrous cometary dust.

Aims. We aim to gain insights into the above classes of bodies by characterizing the internal structure of a large P- and D-type asteroid.

Methods. We report high-angular-resolution imaging observations of the P-type asteroid (87) Sylvia with the Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. These images were used to reconstruct the 3D shape of Sylvia. Our images together with those obtained in the past with large ground-based telescopes were used to study the dynamics of its two satellites. We also modeled Sylvia’s thermal evolution.

Results. The shape of Sylvia appears flattened and elongated (a/b ~1.45; a/c ~1.84). We derive a volume-equivalent diameter of 271 ± 5 km and a low density of 1378 ± 45 kg m−3. The two satellites orbit Sylvia on circular, equatorial orbits. The oblateness of Sylvia should imply a detectable nodal precession which contrasts with the fully-Keplerian dynamics of its two satellites. This reveals an inhomogeneous internal structure, suggesting that Sylvia is differentiated.

Conclusions. Sylvia’s low density and differentiated interior can be explained by partial melting and mass redistribution through water percolation. The outer shell should be composed of material similar to interplanetary dust particles (IDPs) and the core should be similar to aqueously altered IDPs or carbonaceous chondrite meteorites such as the Tagish Lake meteorite. Numerical simulations of the thermal evolution of Sylvia show that for a body of such a size, partial melting was unavoidable due to the decay of long-lived radionuclides. In addition, we show that bodies as small as 130–150 km in diameter should have followed a similar thermal evolution, while smaller objects, such as comets and the KBO Arrokoth, must have remained pristine, which is in agreement with in situ observations of these bodies. NASA Lucy mission target (617) Patroclus (diameter ≈140 km) may, however, be differentiated.
Star-disk interaction in the T Tauri star V2129 Ophiuchi: An evolving accretion-ejection structure
Authors: Sousa A. P. , Bouvier J. , Alencar S. H. P. , Donati J.-F. , Alecian E. , Roquette J. , Perraut K. , Dougados C. , Carmona A. , Covino S. , Fugazza D. , Molinari E. , Moutou C. , Santerne A. , Grankin K. , Artigau É. , Delfosse X. , Hebrard G. ,   the SPIRou consortium
Published: March 2021

Context. Classical T Tauri stars are young low-mass systems still accreting material from their disks. These systems are dynamic on timescales of hours to years. The observed variability can help us infer the physical processes that occur in the circumstellar environment.

Aims. In this work, we aim at understanding the dynamics of the magnetic interaction between the star and the inner accretion disk in young stellar objects. We present the case of the young stellar system V2129 Oph, which is a well-known T Tauri star with a K5 spectral type that is located in the ρ Oph star formation region at a distance of 130 ± 1 pc.

Methods. We performed a time series analysis of this star using high-resolution spectroscopic data at optical wavelengths from CFHT/ESPaDOnS and ESO/HARPS and at infrared wavelengths from CFHT/SPIRou. We also obtained simultaneous photometry from REM and ASAS-SN. The new data sets allowed us to characterize the accretion-ejection structure in this system and to investigate its evolution over a timescale of a decade via comparisons to previous observational campaigns.

Results. We measure radial velocity variations and recover a stellar rotation period of 6.53 days. However, we do not recover the stellar rotation period in the variability of various circumstellar lines, such as Hα and Hβ in the optical or HeI 10830 Å and Paβ in the infrared. Instead, we show that the optical and infrared line profile variations are consistent with a magnetospheric accretion scenario that shows variability with a period of about 6.0 days, shorter than the stellar rotation period. Additionally, we find a period of 8.5 days in Hα and Hβ lines, probably due to a structure located beyond the corotation radius, at a distance of ∼0.09 au. We investigate whether this could be accounted for by a wind component, twisted or multiple accretion funnel flows, or an external disturbance in the inner disk.

Conclusions. We conclude that the dynamics of the accretion-ejection process can vary significantly on a timescale of just a few years in this source, presumably reflecting the evolving magnetic field topology at the stellar surface.
X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
Authors: Sapienza V. , Miceli M. , Peres G. , Bocchino F. , Orlando S. , Greco E. , Combi J. A. , García F. , Sasaki M.
Published: March 2021

Context. The Vela supernova remnant (SNR) shows several ejecta fragments (or shrapnel) protruding beyond the forward shock, which are most likely relics of anisotropies that developed during the supernova (SN) explosion. Recent studies have revealed high Si abundance in two shrapnel (shrapnel A and G), located in opposite directions with respect to the SNR center. This suggests the possible existence of a Si-rich jet-counterjet structure, similar to that observed in the SNR Cassiopea A.

Aims. We analyzed an XMM-Newton observation of a bright clump, behind shrapnel G, which lies along the direction connecting shrapnel A and G. The aim is to study the physical and chemical properties of this clump to ascertain whether it is part of this putative jet-like structure.

Methods. We produced background-corrected and adaptively-smoothed count-rate images and median photon energy maps, and performed a spatially resolved spectral analysis.

Results. We identified two structures with different physical properties. The first one is remarkably elongated along the direction connecting shrapnel A and G. Its X-ray spectrum is much softer than that of the other two shrapnel, to the point of hindering the determination of the Si abundance; however, its physical and chemical properties are consistent with those of shrapnel A and shrapnel G. The second structure, running along the southeast-northwest direction, has a higher temperature and appears similar to a thin filament. By analyzing the ROSAT data, we have found that this filament is part of a very large and coherent structure that we identified in the western rim of the shell.

Conclusions. We obtained a thorough description of the collimated, jet-like tail of shrapnel G in Vela SNR. In addition we discovered a coherent and very extended feature roughly perpendicular to the jet-like structure that we interpret as a signature of an earlier interaction of the remnant with the stellar wind of its progenitor star. The peculiar Ne/O ratio we found in the wind residual may be suggestive of a Wolf-Rayet progenitor for Vela SNR, though further analysis is required to address this point.
Basement-involved thrusting, salt migration and intramontane conglomerates: a case from the Southern Pyrenees
Authors: Burrel Laura , Teixell Antonio , Gómez-Gras David , Coll Xavier
Published: March 2021

The northern margin of the Organyà basin (Southern Pyrenees) has a complex structure in which syn-rift Lower Cretaceous carbonates flank a wide Keuper evaporite province, featuring the leading edges of the basement-involved thrust sheets of the Pyrenean antiformal stack. Recent studies show that Keuper diapirs and salt walls grew during the Cretaceous extensional episode, conditioning the development of differentiated depocenters and minibasins. The role of salt tectonics during the Pyrenean orogeny has not been addressed in previous structural studies, but present-day cross-sections indicate a Keuper evaporite-bearing vertical thickness of up to 3000 m in the Senterada-Gerri de la Sal area. We infer that salt migration was a determinant mechanism in triggering a gentle northward tilting of the Organyà basin during the Eocene-Oligocene, recorded in the La Pobla de Segur and Gurp syn-tectonic conglomerates in a large north-directed onlap, opposite to the main sedimentary influx direction. Contemporaneously, we interpret that salt migration, promoted by conglomerate differential loading, enabled the sinking and rotation of the unrooted Nogueres thrust units (têtes plongeantes). We use new and published structural data for the Lower Cretaceous margin of the Organyà basin, combined with structural and clast provenance data from the Cenozoic alluvial fan conglomerates of La Pobla and Gurp, to understand the Lutetian to late Oligocene evolution of the northern margin of the Central South-Pyrenean Unit. The tectono-sedimentary evolution of this area and the salt evacuation patterns are closely related to the exhumation history of the stacked Paleozoic thrust sheets of the Pyrenean hinterland to the north. In this study, we correlate the movements over a mobile substratum and the paleogeographic changes of conglomeratic basins at the toe of an exhuming orogenic interior.
A decade of seismicity in metropolitan France (2010–2019): the CEA/LDG methodologies and observations
Authors: Duverger Clara , Mazet-Roux Gilles , Bollinger Laurent , Guilhem Trilla Aurélie , Vallage Amaury , Hernandez Bruno , Cansi Yves
Published: March 2021

We summarize ten years of the French seismicity recorded by the Geophysical and Detection Laboratory (LDG) of the French Alternative Energies and Atomic Energy Commission (CEA) network from 2010 to 2019. During this period, 25 265 natural earthquakes were detected by the LDG and located within metropolitan France and its immediate vicinity. This seismicity contributes to more than 47% of the natural earthquakes instrumentally recorded since 1962 (mainly due to the improvement of network capacity), and includes about 28% of the most significant earthquakes with a magnitude ML ≥ 4.0. Recent seismic events therefore significantly expand the available national catalogues. The spatial distribution of 2010–2019 earthquakes is broadly similar to the previously recorded instrumental pattern of seismicity, with most of the seismic activity concentrated in the French Alps, the Pyrenees, Brittany, the upper Rhine Graben and the Central Massif. A large part of the seismic activity is related to individual events. The largest earthquakes of the last ten years include the November 11, 2019 Le Teil earthquake with ML 5.4 and epicentral intensity VII–VIII, which occurred in the Rhone valley; the April 28, 2016 La Rochelle earthquake with ML 5.1 and epicentral intensity V, which occurred at the southernmost extremity of the Armorican Massif in the vicinity of the Oléron island; and the April 7, 2014 Barcelonnette earthquake with ML 5.1 and epicentral intensity V–VI, which occurred in the Ubaye valley in the Alps. In 2019, two other moderate earthquakes of ML 5.1 and ML 4.9 stroke the western part of France, in Charente-Maritime and Maine-et-Loire departments, respectively. The recent moderate earthquake occurrences and the large number of small earthquakes recorded give both the potential to revise some regional historical events and to determine more robust frequency-magnitude distributions, which are critical for seismic hazard assessment but complex due to low seismicity rates in France. The LDG seismic network installed since the early 1960s also allows a better characterization of the temporal structure of seismicity, partly diffused and in the form of mainshock-aftershocks sequences or transient swarms. These aspects are important in order to lower the uncertainties associated to seismogenic sources and improve the models in seismic hazard assessment for metropolitan France.
The Beni Bousera marbles, record of a Triassic-Early Jurassic hyperextended margin in the Alpujarrides-Sebtides units (Rif belt, Morocco)
Authors: Farah Aboubaker , Michard André , Saddiqi Omar , Chalouan Ahmed , Chopin Christian , Montero Pilar , Corsini Michel , Bea Fernando
Published: March 2021

The timing and process of exhumation of the subcontinental peridotites of the Gibraltar Arc (Ronda, Beni Bousera) have been discussed extensively over the last decades. In this work, we contribute to this debate through the first mapping, structural and petrological analyses, and SHRIMP U-Th-Pb dating of high-grade marbles that crop out around the Beni Bousera antiform of the Alpujarrides-Sebtides units of northern Rif (Morocco). These marbles, here termed the Beni Bousera marbles (BBMs), instead of being intercalations in the granulitic envelope (kinzigites) of the Beni Bousera peridotites, as previously described, form minor, dismembered units within a ∼30 to 300 m thick mylonitic contact between the kinzigites and the overlying gneisses of the Filali Unit (Filali–Beni Bousera Shear Zone, FBBSZ). They display silicate-rich dolomitic marbles, sandy-conglomeratic calcareous marbles and thinly bedded marble with interleaved biotite-rich schists. An unconformable contact, either of stratigraphic or tectonic origin, with the underlying kinzigites, is observed locally. Pebbles or detrital grains include K-feldspar, quartz, almandine garnet and zircon. Peak mineral assemblages consist of forsterite, Mg-Al-spinel, geikielite (MgTiO3), phlogopite and accessory zirconolite, baddeleyite and srilankite in dolomite marble, as well as K-feldspar, scapolite, diopside, titanite and accessory graphite and zircon in calcite marble. These assemblages characterize peak HT-LP metamorphic conditions close to 700–750 °C, ≤4.5 kbar. The FBBSZ includes minor ductile thrusts that determine kinzigite horses or slivers carried NW-ward over the marbles. Within the latter, NNE-trending folds are conspicuous. Brittle, northward-dipping normal faults crosscut the FBBSZ ductile structures. Detrital cores of zircon from the BBMs yield two U-Th-Pb age clusters of ∼270 Ma and ∼340 Ma, whereas their rims yield ∼21 Ma ages. Correlations with comparable settings in other West Mediterranean Alpine belts are discussed. The BBMs compare with the Triassic carbonates deposited over the crustal units of the Alpujarrides-Sebtides. The assumed Triassic protoliths may have been deposited onto the kinzigites or carried as extensional allochthons over a detachment in the Early Jurassic during the incipient formation of the Alboran Domain continental margin. Thus, it is concluded that the Beni Bousera mantle rocks were exhumed to a shallow depth during early rifting events responsible for the birth of the Maghrebian Tethys.
Regularity for the planar optimalp-compliance problem
Authors: Bulanyi Bohdan , Lemenant Antoine
Published: March 2021

In this paper we prove a partialC1,αregularity result in dimensionN= 2 for the optimalp-compliance problem, extending forp≠2 some of the results obtained by Chambolleet al.(2017). Because of the lack of good monotonicity estimates for thep-energy whenp≠2, we employ an alternative technique based on a compactness argument leading to ap-energy decay at any flat point. We finally obtain that every optimal set has no loop, is Ahlfors regular, and isC1,αatℌ1-a.e. point for everyp∈ (1, +∞).
Bioaccumulation and health risk assessment of trace elements inMytilus galloprovincialisas sea food in the Al Hoceima coasts (Morocco)
Authors: Azizi Ghizlane , Layachi Mostafa , Akodad Mustapha , Martín-García Antonio Ignacio , Yáñez-Ruiz David R. , Baghour Mourad , Ait Hmeid Hanane , Gueddari Hicham , Moumen Abdelmajid
Published: March 2021

The monthly variations in metal concentration of Cadmium (Cd), Zinc (Zn) and Chromium (Cr) were determined in tissues ofMytilus galloprovincialisand seawater obtained from the mussel farm installed along the Al Hoceima coasts, during the sampling period of 2018. The heavy metals encountered in the bivalves were higher than those observed in their environment with a decreasing order of Zn > Cr > Cd. The results also showed a decreasing trend for the metals studied during the summer sampling campaign. The maximum values were obtained during the wet periods. The monthly variations in trace metals observed in the mussel tissues were due to environmental parameters and the physiological state of the bivalves. Our results revealed that the average concentrations of pollutants found inM. galloprovincialiswere below the limits allowed by the Food and Agriculture Organization of the United Nations (FAO) which are 2.0, 1000 and 1.0 mg/kg, for Cd, Zn and Cr, respectively in molluscan shellfish for human consumption. Therefore, the trace elements present in the tissues of Al Hoceima shore mussels do not represent a risk to human health associated with their consumption, even during the period of their maximum bioaccumulation. Our work highlights the potential use ofMytilus galloprovincialisin the Biomonitoring of metallic pollutants in this region of the northern Moroccan coasts.
Assessment of groundwater quality using statistical methods in the Isly basin (Horst Belt, Morocco)
Authors: Ziani Soufiane , Khattach Driss , Abderbi Jamila , Nouayti Nordine , Makkaoui Mohamed
Published: March 2021

The identification of potential sources of groundwater pollution in the Isly basin (North-East Morocco) and the understanding of their spatial variability, in response to certain natural and anthropogenic forcings, were approached through the combined study of ionic ratios and statistical analyses of hydro-chemical data. The results of the Principal Component Analysis (PCA) show that two factors explain nearly 78% of the variance. Factor 1 is mineral salts (Cl and Na), and factor 2 is related to alkaline earth metals (Ca and Mg). The typological structure of the F1 x F2 plan analysis shows four regions according to the nature of pollutants. The contaminations observed for most of the water points could be related to anthropogenic, geological and atmospheric pollution sources.
The ISO 14001 environmental management system, a lever for performance and competitiveness of the Moroccan industrial company
Authors: Gazoulit Sarra , Oubal Khadija
Published: March 2021

For some years now, Moroccan industrial companies have begun to integrate the environment into their management and to set up an environmental management system, in compliance with international standards, in order to meet the requirements of stakeholders. The fact remains that this management tool has enabled companies to control the impact of their activity on the environment by promoting manufacturing excellence. On a sample of twenty-two large industrial companies with a response rate of 55%, we conducted a quantitative and qualitative study, which allowed us to show the importance of EMS iso 14001 on the performance and competitiveness of the Moroccan industrial company.
Valorisation of food waste as new raw materials in broiler feed
Authors: Mechkirrou Latifa , Ouhssine Mohammed , Afilal Mohamed El Amine
Published: March 2021

In Morocco, the food waste fraction constitutes a large part of the total municipal solid waste generated. In order to promote this fraction as a feed source for poultry, a study was carried out to evaluate its digestive and metabolic effects, as well as its nutritional value on broilers. Indeed, comparative tests were carried out on two separate batches of small broilers fed, successively, with a commercial compound feed (CCF), and a feed prepared in the laboratory using kitchen waste as a substitute (LPF). The results obtained throughout the rearing period revealed the feasibility of the valorization of food waste as a substitute promoted in the poultry feed sector. In addition, the prefabricated feeds gave the same feed consumption index (1.03), compared to the commercial compound feed applied in the same rearing farm, while the weight gain index results were more advantageous for FPL. The study demonstrates the valorisation of feed waste as a new substitute for poultry feed.
Valorisation of cold-pressed almond oil’s cake as raw material for the preparation of naturally gluten-free flour for specific food applications
Authors: Houmy Nadia , Melhaoui Reda , Kodad Souhayla , Zantar Said , Elamrani Ahmed
Published: March 2021

Almond cake is a by-product of mechanical press extraction of almond oil intended mainly for the cosmetics industry. According to the circular economy for zero waste, the purpose is to reuse this byproduct to prepare natural gluten-free flour to replace part or all of the whole soft wheat flour (SWF) in specific foods. The almond by-product after grinding was sifted on a sieving shaker equipped with 4 mesh sieves 1mm, 500µm, 250µm, and 100µm. The obtained fractions were compared with SWF, based on analysis’s results for ash and colour (L*, a*, b*), contents of proteins, fibres, total sugars, reducing sugars and bulk density. Significant difference was detected between the gluten free fractions of almond meal and SWF, particularly for protein content and colour. The flour obtained from the almond cake is naturally gluten-free; therefore, it cannot have the properties of a baker’s flour of soft Wheat. This naturally gluten free flour would be suitable for gluten free specific baked goods, like cookies, biscuits and crackers, particularly intended to celiac people who cannot consume bakery products made from flour of certain cereals (wheat, barley, rye, oats), or their derivatives.
Sedimentological and lithostratigraphic study of the Foum El Kous Senonian, Central Hight Atlas of Morocco
Authors: Farah Abdelouhed , Algouti Ahmed , Algouti Abdellah , Hadach Fatiha , Mourabit zahra
Published: March 2021

The study area belongs to the southern edge of the central High Atlas. It is limited to the North by the Sub-atlasic accident and to the South by the extension of the Eastern Anti Atlas formations. To determine the depositional environments of the Senonian series, a sedimentological analysis of the facies was carried out based on field observations by the recognition of sedimentary structures and textures. An exoscopic analysis of the quartz grains was also carried out by a systematic prospecting of the grain relief and of all the characters that will appear on the surface of the grain after the formation of the mother rock at the origin place, during transport, immobilization phases and deposition. It seems very interesting to prospect for the clayey side in these Upper Cretaceous reddish formations because the evolution of the clayey and non-clayey assemblages in this central basin of the High Atlas will depend mainly on the combination of tectonic, eustatic, climatic and other influences. The Senonian of Foum El Kous which has a less important thickness corresponds to continental deposits that act the role of a natural barrier that separates on both sides the two sub-basins: Sidi Ali Oubork in the East and Ait youl in the West.
Lithological mapping and automatic lineament extraction using Aster and Gdem data in the Imini-Ounilla-Asfalou district, South High Atlas of Marrakech, Morocco
Authors: Farah Abdelouhed , Algouti Ahmed , Algouti Abdellah , El badaoui Kamal , Errami Maryam , Ifkirne Mohammed
Published: March 2021

Lithological and lineament mapping using remote sensing is a fundamental step in various geological studies, as it forms the basis for the interpretation and validation of the results obtained. There were two objectives for this study, applied in the Imini-Ounilla-Asfalou district, South High Atlas of Marrakech region: first, lithological mapping by satellite image processing techniques such as ASTER L1B (hight spectral and spatial resolution), namely Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), as well as the application of three types of supervised classification, namely Spectral Angle Mapper (SAM), Maximum Likelihood (ML) and Minimum Distance (MD), on the visible/near-infrared (VNIR) and short-wave infrared (SWIR) spectral bands of our ASTER image; second, an analysis of the distribution of lineaments by automatic extraction using a Global Digital Elevation Model (GDEM) and the PC1 image derived from the PCA transformation applied to the satellite image. The best results are highlighted by the delineation of new facies in relation to the existing map; after confirmation in the field, all of these facies, which include Eocene, Triassic and Jurassic formations, are represented on the new map. The results of lineaments showed that each of them systematically shows a similarity in terms of concentration and orientation, with four preferential oriented systems: NE-SW, E-W, NNE-SSW and NW-SE. The lineaments mainly follow those of the major fault zones, with high concentrations in the northeast and southwest parts of the study area.
NZEB and market-based renovation case study of an existing office building
Authors: Kuivjõgi Helena , Kurnitski Jarek , Uutar Aivar , Thalfeldt Martin
Published: March 2021

The goal of decarbonizing the building stock in the EU requires a multi-fold increase of the current renovation rates. In Estonia, the non-residential building sector has had little or no public support to improve the energy efficiency. Therefore, it is essential to study the energy efficient and cost-optimal measures for non-residential building renovation to give guidance to real estate companies and other stakeholders about the renovation alternatives. Furthermore, crucial is to provide input to the government to develop the renovation grant and incentives for renovation. In this study, energy renovation measures and savings to improve the energy performance to NZEB level were identified in a large (16 990 m2heated area) office building. For that purpose, energy use was measured, simulation model developed and calibrated, feasible and more comprehensive energy improvements and costs analysed. The improvement of lighting, AHU, heating, installation of a 69 kW PV system, and window replacement was needed to achieve the goal with a primary energy use of 163 kWh/m2. However, some of the applied measures had long payback times of 40-70 years and are not realistic to be implemented without renovation incentives.
Assessing the performance and cost-competitiveness of a dual-source solar assisted heat pump in cold climates
Authors: Sager Jeremy , Poirier Jean-Philippe
Published: March 2021

In many cold climates, the coincidence of long heating seasons as well as relatively high levels of solar insolation offer an opportunity to explore the potential for solar-assisted air source heat pumps to meet greenhouse gas reduction objectives for space and water heating systems. This paper presents the results of a detailed performance analysis based on 6 months of field test data of a pre-commercial, dual source solar-assisted heat pump. The data gathered during field-testing as well as the functionality of the system were studied extensively to develop and calibrate an hourly energy model. The model replicates the performance and operating modes of the solar-assisted air source heat pump. It allows for an hourly assessment of the energy savings, greenhouse gas reduction potential and cost competitiveness of this system as compared to other high performance HVAC systems in a variety of climate locations and archetype house loads. A parametric analysis is undertaken to assess the impact of key components on system viability. Results indicate that for some regions and archetype house loads, the dual-source solar-assisted heat pump can lead to significant energy savings and GHG emissions reductions when compared to high performing HVAC systems. These savings may enable a favorable payback period when a competitive capital cost is considered. The objective of the study was to identify locations and archetypes in which this solar-assisted heat pump topology may make sense for further development and demonstration.
Investigation of the impacts of design parameters on thermal performance of buildings in cold climate
Authors: Gaitov Rashid , Tokbolat Serik , Zhong Hua , Mustafa Mohamad
Published: March 2021

While design optimization of buildings seeks to improve energy efficiency and, thus, leads to greenhouse gas emissions reduction, the thermal performance of buildings can be compromised. Thermal performance is an important aspect as it directly affects the health and well-being of occupants. This study aims to investigate using a simple simulation tool to examine the correlation between a set of building physical design parameters such as orientation, shading and shape, optimization of which helps to make a positive impact on the thermal performance of the building in a cold climate zone. The thermal performance simulation tool Passive Design Assistant (PDA) was used to build a simulation model and test the interdependence between the design parameters and thermal performance. The results indicate that modifications of building’s parameters such as orientation and shape or the addition of shadings lead to improvements of the internal thermal temperature, heat gain and loss, hence the optimal parameters should prevail. A case study for cold climate is analyzed, in Nur-Sultan, Kazakhstan, the optimal orientation for the squared building is 30° from East to South (building rotated 120°) and the optimal building’s shape is rectangular, which attracts up to 2.6 times higher solar gains than the square one. Moreover, the use of shadings can regulate the internal temperature of the building by 2 °C. General recommendations based on the findings are made and could be considered in the earlier stage of building design and construction processes.
Impact of internal heat gain profiles on the design cooling capacity of landscaped offices
Authors: Seyed Salehi Seyed Shahabaldin , Ferrantelli Andrea , Aljas Hans Kristjan , Kurnitski Jarek , Thalfeldt Martin
Published: March 2021

Using passive methods in façade design for controlling heating and cooling needs is an important prerequisite for constructing cost-effective nearly zero-energy buildings. Optimal control of solar heat gains reduces the cooling demand and the size of the active cooling systems. However, applying such methods increases the impact of internal heat gains on the heat balance of the buildings, and accordingly also the dimensions of cooling systems. Therefore, a good model of internal heat gains is needed for a reliable and optimal sizing of the cooling sources. This paper aims to bring understanding to developing internal heat gains models for sizing the cooling systems. For this purpose, several weekly internal heat gain profiles were selected from a large set of tenant-based electricity use measured in 4 office buildings in Tallinn. The selection was based on maximum daily or weekly peak loads of an office space per floor area. The selected profiles and the schedule of EN 16798-1 were used to dimension ideal coolers in the zones of a generic floor model with landscaped offices developed in IDA-ICE 4.8. The model had variable window sizes and thermal mass of the building materials. Finally, the internal heat gains models resulting in the largest cooling capacity were identified. We found that utilizing thermal mass can reduce the cooling system size by up to 7% on average and the models with big windows and light structure need the largest cooling systems. The cooling loads obtained with the profile of EN 16798-1 did not significantly differ from the average of other profiles’ results. This paper focused mainly on the zonal dimensioning of cooling systems, therefore a more in-depth analysis of the different occupancy patterns as well as developing models for dimensioning the cooling system at the building level, is needed.
Identifying Heating Technologies suitable for Historic Churches, Taking into Account Heating Strategy and Conservation through Pairwise Analysis
Authors: Talbot Robin , Hashemi Arman , Ashton Philip , Picco Marco
Published: March 2021

As a result of difficulty meeting energy efficiency through fabric alteration, historic churches must focus on heating systems and operational strategy as key to reducing carbon emissions. Strategies can be defined as local or central heating. Local heating strives to heat occupants, while central heating aims to heat the building fabric and therefore the occupants. Each strategy requires a different approach to control and technology in response to priorities such as conservation, comfort and cost. This paper reviews current and emerging technologies in the context of church heating. The fuel source, heat generation technology and heat emitter are arranged in a matrix, with pairwise analysis undertaken to create weightings for each assessment criteria. The process of constructing the matrix and undertaking pairwise analysis using personas is discussed. The result is a ranking of fuels and technologies appropriate to the main priorities and individual preferences. Some desirable technologies are inherently more damaging to historic church environments due to invasive installation. These technologies score poorly when the aim is fabric preservation. Greener fuels, like biomass, may rank lower than fossil fuels, due in part to operational differences.
Parameters for Thermal Energy Systems Resilience
Authors: Zhivov Alexander M.
Published: March 2021

To provide a building design that is robust, adaptable, and affordable, one must understand the aspects of the building’s geographic location that will impact equipment selections, operating hours, and maintenance needs. One must also consider the building’s “thermal resilience,” i.e., its ability to withstand a heating plant outage. Designing for resilience is of growing importance, especially for military and government installations that must maintain critical functions even during outages. Buildings with a fast rate of temperature degradation with the loss of heating system function have low resiliency; buildings with a slower rate of temperature degradation have higher resiliency. In extreme cold climates, resiliency can play an integral role in protecting property during an outage. A drop in indoor temperature can pose a risk of freezing plumbing, which can lead to burst pipes and interior flooding that can cause enormous and costly damage, and which can effect a loss of workspace in an office building. More resilient designs must consider not only building HVAC installations, but also building envelope and the whole energy infrastructure, including thermal capacity of concrete and brick walls, internal water pipes, critical system redundancy, outside insulation without weak points, and a centrally controlled, low carbon hot water heat supply. This paper describes a quantitative approach to evaluate a system’s resiliency based on analytical and experimental studies conducted under IEA EBC Annex 73 and the Environmental Security Technology Certification Program (ESTCP) project Technologies Integration to Achieve Resilient, Low-Energy Military Installations, to evaluate building energy performance in extreme climate conditions. This work recommends that more thermally resilient designs for buildings in cold climates include consideration of increased thermal resistance of the building envelope, improved whole-building airtightness, and higher thermal mass.
Estimation of energy-saving potential and indoor thermal comfort by the central control of the heating curve in old apartment buildings
Authors: Hajian Hatef , Ahmed Kaiser , Kurnitski Jarek
Published: March 2021

In this research, an existing building calibrated simulation model from 1981 was built based on measured energy and indoor temperature data. The model was used to study the central control's energy-saving potential. With parametric simulations, DHW circulation internal heat gain and ventilation airflow rate was determined as 85% and 0.29 l/s/m², respectively. DHW circulation heat loss has been found almost as high as DHW use. Dropping the heating curve from 70/40 °C to 65/35 °C resulted in a saving of 0.6 kWh/m²a (0.8% of space heating energy) on the cost of thermal comfort as yearly hours of the mean air temperature below 21 °C rose from 2.7% to 9.0%. It was necessary to reduce the heating curve to 55/25 °C in a hypothetical scenario with fully open thermostats, indicating heat redistribution from warmer to colder rooms, leading to higher heating energy. The findings indicate no energy saving potential due to compromising thermal comfort even by 5 °C heating curve reduction. It was revealed that the building average indoor temperature is not a factor to estimate energy-saving potential because of too low temperature in the coldest apartments.