bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon-Free Solution-Based Doping for Silicon
Authors: Caccamo Sebastiano , Puglisi Rosaria Anna
Published: August 2021

Molecular doping is a method to dope semiconductors based on the use of liquid solutions as precursors of the dopant. The molecules are deposited on the material, forming a self-ordered monolayer that conforms to the surfaces, whether they are planar or structured. So far, molecular doping has been used with precursors of organic molecules, which also release the carbon in the semiconductor. The carbon atoms, acting as traps for charge carriers, deteriorate the doping efficiency. For rapid and extensive industrial exploitation, the need for a method that removes carbon has therefore been raised. In this paper, we use phosphoric acid as a precursor of the dopant. It does not contain carbon and has a smaller steric footprint than the molecules used in the literature, thus allowing a much higher predetermined surface density. We demonstrate doses of electrical carriers as high as 3 × 1015 #/cm2, with peaks of 1 × 1020 #/cm3, and high repeatability of the process, indicating an outstanding yield compared to traditional MD methods.
Jujube Powder Enhances Cyclophosphamide Efficiency against Murine Colon Cancer by Enriching CD8+ T Cells While Inhibiting Eosinophilia
Authors: Zhuang Huiren , Jing Nan , Wang Luoyang , Jiang Guoqiang , Liu Zheng
Published: August 2021

Cyclophosphamide (CTX) is widely applied in cancer treatment. However, the outcome is often compromised by lymphopenia, myelosuppression, and gut dysbiosis. Here, we used jujube powder to enhance CTX efficiency through nurturing gut microbiota in order to facilitate favorable metabolisms. It was observed that the oral administration of jujube powder enriched CD8+ T cells in mouse MC38 colon tumor microenvironment and increased the diversity of gut microbiota and the abundance of Bifidobacteriales, which is helpful to the production of butyrate in the cecum content. The application of jujube powder also stimulated the production of white blood cells, especially CD8+ T cells in peripheral and bone marrow, while inhibiting the growth of eosinophils in peripheral blood and the production of IL-7 and GM-CSF in serum. All these are conductive to the significant inhibition of the tumor growth, suggesting the high potential of nurturing gut microbiota with natural products for improving the efficiency of chemotherapy.
The “Epulis” Dilemma. Considerations from Provisional to Final Diagnosis. A Systematic Review
Authors: Costa Paola , Peditto Matteo , Marcianò Antonia , Barresi Antonio , Oteri Giacomo
Published: August 2021

“Epulis” is a widely used term to describe a localized gingival enlargement. However, a wide range of neoformations might present as localized, slow-growing, asymptomatic gingival masses. A systematic review was conducted to outline the pathological entities that were provisionally dignosed as “epulis” and whose final diagnosis was made after microscopic examination. An electronic search of PubMed, Google Scholar and Scopus databases from January 2000 to February 2021 was performed. An initial search of the databases identified a total of 864 documents, and after a careful process of screening and selection, 14 studies were included in this systematic review and processed for data extraction. The results show that histological examination, sometimes combined with immunohistochemistry, might reveal a wide spectrum of lesions, including hamartomatous lesions, non-neoplastic lesions, benign and malign neoplasms and metastases from distant cancers.
Antigenic Diversity of Human Norovirus Capsid Proteins Based on the Cross-Reactivities of Their Antisera
Authors: Gao Junshan , Zuo Yueting , Xue Liang , Wang Linping , Liang Yanhui , Jiang Yueting , Cai Weicheng , Meng Luobing , Zhang Jumei , Ye Qinghua , Wu Shi , Gu Qihui , Lei Tao , Wu Qingping
Published: August 2021

Human norovirus (HuNoV), which is the major causative agent of acute gastroenteritis, has broad antigenic diversity; thus, the development of a broad-spectrum vaccine is challenging. To establish the relationship between viral genetic diversity and antigenic diversity, capsid P proteins and antisera of seven GI and 16 GII HuNoV genotypes were analyzed. Enzyme-linked immunosorbent assays showed that HuNoV antisera strongly reacted with the homologous capsid P proteins (with titers > 5 × 104). However, 17 (73.9%) antisera had weak or no cross-reactivity with heterologous genotypes. Interestingly, the GII.5 antiserum cross-reacted with seven (30.4%) capsid P proteins (including pandemic genotypes GII.4 and GII.17), indicating its potential use for HuNoV vaccine development. Moreover, GI.2 and GI.6 antigens reacted widely with heterologous antisera (n ≥ 5). Sequence alignment and phylogenetic analyses of the P proteins revealed conserved regions, which may be responsible for the immune crossover reactivity observed. These findings may be helpful in identifying broad-spectrum epitopes with clinical value for the development of a future vaccine.
Synthesis, Biological Evaluation, and In Silico Modeling of N-Substituted Quinoxaline-2-Carboxamides
Authors: Bouz Ghada , Bouz Sarah , Janďourek Ondřej , Konečná Klára , Bárta Pavel , Vinšová Jarmila , Doležal Martin , Zitko Jan
Published: August 2021

Despite the established treatment regimens, tuberculosis remains an alarming threat to public health according to WHO. Novel agents are needed to overcome the increasing rate of resistance and perhaps achieve eradication. As part of our long-term research on pyrazine derived compounds, we prepared a series of their ortho fused derivatives, N-phenyl- and N-benzyl quinoxaline-2-carboxamides, and evaluated their in vitro antimycobacterial activity. In vitro activity against Mycobacterium tuberculosis H37Ra (represented by minimum inhibitory concentration, MIC) ranged between 3.91–500 µg/mL, with most compounds having moderate to good activities (MIC < 15.625 µg/mL). The majority of the active compounds belonged to the N-benzyl group. In addition to antimycobacterial activity assessment, final compounds were screened for their in vitro cytotoxicity. N-(naphthalen-1-ylmethyl)quinoxaline-2-carboxamide (compound 29) was identified as a potential antineoplastic agent with selective cytotoxicity against hepatic (HepG2), ovarian (SK-OV-3), and prostate (PC-3) cancer cells lines. Molecular docking showed that human DNA topoisomerase and vascular endothelial growth factor receptor could be potential targets for 29.
G-Quadruplexes and Their Ligands: Biophysical Methods to Unravel G-Quadruplex/Ligand Interactions
Authors: Santos Tiago , Salgado Gilmar F. , Cabrita Eurico J. , Cruz Carla
Published: August 2021

Progress in the design of G-quadruplex (G4) binding ligands relies on the availability of approaches that assess the binding mode and nature of the interactions between G4 forming sequences and their putative ligands. The experimental approaches used to characterize G4/ligand interactions can be categorized into structure-based methods (circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography), affinity and apparent affinity-based methods (surface plasmon resonance (SPR), isothermal titration calorimetry (ITC) and mass spectrometry (MS)), and high-throughput methods (fluorescence resonance energy transfer (FRET)-melting, G4-fluorescent intercalator displacement assay (G4-FID), affinity chromatography and microarrays. Each method has unique advantages and drawbacks, which makes it essential to select the ideal strategies for the biological question being addressed. The structural- and affinity and apparent affinity-based methods are in several cases complex and/or time-consuming and can be combined with fast and cheap high-throughput approaches to improve the design and development of new potential G4 ligands. In recent years, the joint use of these techniques permitted the discovery of a huge number of G4 ligands investigated for diagnostic and therapeutic purposes. Overall, this review article highlights in detail the most commonly used approaches to characterize the G4/ligand interactions, as well as the applications and types of information that can be obtained from the use of each technique.
Creation of a Pharmacy Student Longitudinal Rotation to Expand the Scope of an Antimicrobial Stewardship Program
Authors: Ward Tiffany , Fredenrich Jaela
Published: August 2021

Allergy assessments and penicillin skin testing have emerged as a vital intervention for Antimicrobial Stewardship Programs (ASPs). Investment and involvement in such programs by ASPs, however, are often limited due to resources, time, and personnel constraints. Harnessing an underutilized resource, 4th-year advanced pharmacy practice experience (APPE) students, allows for expanded ASP involvement and scope of practice. We aim to outline and provide insight on how 4th-year APPE students serve as an asset to an ASP. Through our novel longitudinal rotation experience, APPE students complete penicillin allergy assessments, patient education, and work alongside a clinical pharmacist to refer patients for penicillin skin testing if appropriate. Students also achieve many of the education standards required by the Accreditation Counsel for Pharmacy Education (ACPE) for graduation within the Doctor of Pharmacy degree while developing a strong foundation in antimicrobial stewardship and gaining invaluable knowledge for their future. The addition of APPE pharmacy students to our ASP has also enabled our program to achieve its goals and expand involvement and reach within our facility.
Development of a 1 TW/35 fs Ti:sapphire Laser Amplifier and Generation of Intense THz Waves Using Two-Color Laser Filamentation
Authors: Phung Vanessa Ling Jen , Kang Keekon , Jeon Seongjin , Kim Jinju , Roh Kyungmin , Suk Hyyong
Published: August 2021

We developed a compact Ti:sapphire laser amplifier system in our laboratory, generating intense laser pulses with a peak power of >1 TW (terawatt), a pulse duration of 34 fs (femtosecond), a central wavelength of 800 nm, and a repetition rate of 10 Hz. The laser amplifier system consists of a mode-locked Ti:sapphire oscillator, a regenerative amplifier, and a single-side-pumped 4-pass amplifier. The chirped-pulse amplification (CPA)-based laser amplifier was found to provide an energy of 49.6 mJ after compression by gratings in air, where the pumping fluence of 1.88 J/cm2 was used. The amplified spontaneous emission (ASE) level was measured to be lower than 10−7, and ps-prepulses were in 10−4 or lower level. The developed laser amplifier system was used for the generation of intense THz (terahertz) waves by focusing the original (800 nm) and second harmonic (400 nm) laser pulses in air. The THz pulse energy was shown to be saturated in the high laser energy regime, and this phenomenon was confirmed by fully electromagnetic, relativistic, and self-consistent particle-in-cell (PIC) simulations.
Unusual Para-Substituent Effects on the Intramolecular Hydrogen Bond in Hydrazone-Based Switches: Insights from Chemical Landscape Analysis and DFT Calculations
Authors: Paskaleva Vesselina , Dobrev Stefan , Kochev Nikolay , Angelova Silvia , Antonov Liudmil
Published: August 2021

Тhe adequacy of chemical property predictions strongly depends on the structure representation, including the proper treatment of the tautomeric and isomeric forms. A combination of an in-house developed open-source tool for automatic generation of tautomers, Ambit-Tautomer, based on H-atom shift rules and standard quantum chemical (DFT) calculations is used for a detailed investigation of the possible geometric isomers, conformers and tautomers of unsubstituted and para-substituted phenylhydrazones, systems with experimentally observed unusual para-substituent effects on the intramolecular hydrogen bond (IMHB) for E-isomers of the compounds. The computational results show that the energetically preferred E-isomers are characterized by stronger IMHBs than the corresponding Z-isomers. The HN–N=C–C=N molecular fragment in the E-configurations is less sensitive to the substitution effect than the HN–N=C–C=O fragment in the isomers with Z-configuration. A probable reason for this decreased sensitivity of E-isomers to phenyl ring substitution is the more efficient conjugation and charge distribution in the HN–N=C–C=N fragment.
Oil-Based Polymer Coatings on CAN Fertilizer in Oilseed Rape (Brassica napus L.) Nutrition
Authors: Škarpa Petr , Mikušová Dominika , Antošovský Jiří , Kučera Milan , Ryant Pavel
Published: August 2021

Fertilizer coating can increase the efficiency of N fertilizers and reduce their negative impact on the environment. This may be achieved by the utilization of biodegradable natural coating materials instead of polyurethane-based polymers. The aim of this study was to detect the effect of calcium ammonium nitrate (CAN) fertilizer coated with modified conventional polyurethane enhanced with vegetable oils on the yield and quality of Brassica napus L. compared to CAN fertilizer with a vegetable oil-based polymer and to assess the risks of nitrogen loss. Three types of treatments were tested for both coated fertilizers: divided application (CAN, coated CAN), a single application of coated CAN, and a single application of CAN with coated CAN (1:2). A single application of coated CAN with both types of coating in the growth stage of the 9th true leaf significantly increased the yield, the thousand seed weight, and oil production compared to the uncoated CAN. The potential of using coated CAN may be seen in a slow nitrogen release ensuring the nitrogen demand for rapeseed plants throughout vegetation and eliminating the risk of its loss. The increased potential of NH4+ volatilization and NO3− leaching were determined using the uncoated CAN fertilizer compared to the coated variants. Oil-based polymer coatings on CAN fertilizer can be considered as an adequate replacement for partially modified conventional polyurethane.
Double Crystallization and Phase Separation in Polyethylene—Syndiotactic Polypropylene Di-Block Copolymers
Authors: De Rosa Claudio , Di Girolamo Rocco , Cicolella Alessandra , Talarico Giovanni , Scoti Miriam
Published: August 2021

Crystallization and phase separation in the melt in semicrystalline block copolymers (BCPs) compete in defining the final solid state structure and morphology. In crystalline–crystalline di-block copolymers the sequence of crystallization of the two blocks plays a definitive role. In this work we show that the use of epitaxial crystallization on selected crystalline substrates allows achieving of a control over the crystallization of the blocks by inducing crystal orientations of the different crystalline phases and a final control over the global morphology. A sample of polyethylene-block-syndiotactic polypropylene (PE-b-sPP) block copolymers has been synthesized with a stereoselective living organometallic catalyst and epitaxially crystallized onto crystals of two different crystalline substrates, p-terphenyl (3Ph) and benzoic acid (BA). The epitaxial crystallization on both substrates produces formation of highly ordered morphologies with crystalline lamellae of sPP and PE highly oriented along one direction. However, the epitaxial crystallization onto 3Ph should generate a single orientation of sPP crystalline lamellae highly aligned along one direction and a double orientation of PE lamellae, whereas BA crystals should induce high orientation of only PE crystalline lamellae. Thanks to the use of the two selective substrates, the final morphology reveals the sequence of crystallization events during cooling from the melt and what is the dominant event that drives the final morphology. The observed single orientation of both crystalline PE and sPP phases on both substrates, indeed, indicates that sPP crystallizes first onto 3Ph defining the overall morphology and PE crystallizes after sPP in the confined interlamellar sPP regions. Instead, PE crystallizes first onto BA defining the overall morphology and sPP crystallizes after PE in the confined interlamellar PE regions. This allows for discriminating between the different crystalline phases and defining the final morphology, which depends on which polymer block crystallizes first on the substrate. This work also shows that the use of epitaxial crystallization and the choice of suitable substrate offer a means to produce oriented nanostructures and morphologies of block copolymers depending on the composition and the substrates.
Impact Response and Damage Tolerance of Hybrid Glass/Kevlar-Fibre Epoxy Structural Composites
Authors: Alagumalai Vasudevan , Shanmugam Vigneshwaran , Balasubramanian Navin Kumar , Krishnamoorthy Yoganandam , Ganesan Velmurugan , Försth Michael , Sas Gabriel , Berto Filippo , Chanda Avishek , Das Oisik
Published: August 2021

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 3 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60°), whereas the E-glass fibre layers were maintained at 0° orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45° fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45° fibre orientation was 58.68 J, which was 14% and 22% higher than the 0° and 60° oriented composites.
Classification of Textile Polymer Composites: Recent Trends and Challenges
Authors: Amor Nesrine , Noman Muhammad Tayyab , Petru Michal
Published: August 2021

Polymer based textile composites have gained much attention in recent years and gradually transformed the growth of industries especially automobiles, construction, aerospace and composites. The inclusion of natural polymeric fibres as reinforcement in carbon fibre reinforced composites manufacturing delineates an economic way, enhances their surface, structural and mechanical properties by providing better bonding conditions. Almost all textile-based products are associated with quality, price and consumer’s satisfaction. Therefore, classification of textiles products and fibre reinforced polymer composites is a challenging task. This paper focuses on the classification of various problems in textile processes and fibre reinforced polymer composites by artificial neural networks, genetic algorithm and fuzzy logic. Moreover, their limitations associated with state-of-the-art processes and some relatively new and sequential classification methods are also proposed and discussed in detail in this paper.
Comparative Failure Study of Different Bonded Basalt Fiber-Reinforced Polymer (BFRP)-AL Joints in a Humid and Hot Environment
Authors: Fan Yisa , Guo Jinzhan , Wang Xiaopeng , Xia Yu , Han Peng , Shangguan Linjian , Zhang Mingyue
Published: August 2021

Fiber-reinforced polymer (FRP) materials are increasingly used in automotive industrial fields to achieve lightweight. In order to study the influence of high temperature and high humidity on the bonding structure between different materials, this paper selects basalt fiber-reinforced resin composite materials (BFRP) and aluminum alloy (Al), and uses Araldite® 2012 and Araldite® 2014, two adhesives, to make single lap joints (SLJs). The aging test was carried out for 0 (unaged), 10, 20, and 30 days under the environment of 80 °C/95% relative humidity (RH) and 80 °C/pure water. In this work, simple Fickian law was used to simulate the hygroscopic change law of dumbbell specimens of two adhesives and BFRP in a pure water environment. It was discovered that Araldite® 2012 is most affected by moisture, but the time to reach the maximum water absorption in Araldite® 2014 was shorter than in Araldite® 2012. The failure strength of the joint was obtained through a quasi-static tensile experiment, and it was found that the Araldite® 2014 adhesive joint first increased and then decreased in a high temperature environment. The strength increased by 11.63% after 20 days of aging under an 80 °C/95%RH environment, and increased by 16.66% after 10 days of aging under an 80 °C/pure water environment, which indicates that post-curing reaction occurred. The strength of Araldite® 2012 joints showed a downward trend. After 30 days of aging, it reduced by 40.38% under an 80 °C/95%RH environment and 41.11% under an 80 °C/pure water environment. By observing the load-displacement curve, it was found that, as time increased, the slope of the curve decreased, indicating that the stiffness of the bonded joint decreased with time. The failure modes of the joints were analyzed by macroscopic images and microscopic SEM methods, and the results showed that the surface failure transitions from a mixed failure to a complete tear failure over time. The failure of the basalt fiber/resin interface was because the interaction between the epoxy resin in the adhesive and the epoxy resin in BFRP was greater than the force between the basalt fiber layer and the epoxy resin layer in the BFRP sheet.
Introducing Deep Eutectic Solvents as a Water-Free Dyeing Medium for Poly (1,4-cYclohexane Dimethylene Isosorbide Terephthalate) PICT Nanofibers
Authors: Hussain Nadir , Hussain Sadam , Mehdi Mujahid , Khatri Muzamil , Ullah Sana , Khatri Zeeshan , Van Langenhove Lieva , Kim Ick Soo
Published: August 2021

Water, one of the most priceless sources of life, is becoming dangerously threatened and contaminated due to population growth, industrial development, and climatic variations. The drainage of industrial, farming, and municipal sewage into drinking water sources pollutes the water. The textile processing industry is one of the major consumers of water. Herein, the idea of water-free dyeing of electrospun poly (1, 4-cyclohexane dimethylene isosorbide terephthalate) PICT nanofibers is proposed. For this, two different deep eutectic solvents (DE solvents) were introduced as an alternative to water for the dyeing of PICT nanofibers in order to develop a water-free dyeing medium. For this, C.I. disperse red 167 was used as a model dye to improve the aesthetic properties of PICT nanofibers. PICT nanofibers were dyed by conventional batch dyeing and ultrasonic dyeing methods to investigate the effect of the dyeing technique on color buildup characteristics. Dyeing conditions such as dyeing time, temperature and, dye-concentration were optimized. Morphological and chemical characterization observations revealed a smooth morphology of dyed and undyed PICT nanofibers. The ultrasonically dyed nanofibers showed higher color strength and increased tensile strength compared to conventionally dyed nanofibers. Further, the consumption of electrical and thermal energy was also calculated for both processes. The results confirmed that the ultrasonic dyeing method can save 58% on electrical energy and 25% on thermal energy as compared to conventional dyeing.
A Brief Review on the Influence of Ionic Liquids on the Mechanical, Thermal, and Chemical Properties of Biodegradable Polymer Composites
Authors: Shamsuri Ahmad Adlie , Md. Jamil Siti Nurul Ain , Abdan Khalina
Published: August 2021

Biodegradable polymers are an exceptional class of polymers that can be decomposed by bacteria. They have received significant interest from researchers in several fields. Besides this, biodegradable polymers can also be incorporated with fillers to fabricate biodegradable polymer composites. Recently, a variety of ionic liquids have also been applied in the fabrication of the polymer composites. In this brief review, two types of fillers that are utilized for the fabrication of biodegradable polymer composites, specifically organic fillers and inorganic fillers, are described. Three types of synthetic biodegradable polymers that are commonly used in biodegradable polymer composites, namely polylactic acid (PLA), polybutylene succinate (PBS), and polycaprolactone (PCL), are reviewed as well. Additionally, the influence of two types of ionic liquid, namely alkylimidazolium- and alkylphosphonium-based ionic liquids, on the mechanical, thermal, and chemical properties of the polymer composites, is also briefly reviewed. This review may be beneficial in providing insights into polymer composite investigators by enhancing the properties of biodegradable polymer composites via the employment of ionic liquids.
Composite Slow-Release Fouling Release Coating Inspired by Synergistic Anti-Fouling Effect of Scaly Fish
Authors: Mo Yanqiang , Xue Peihong , Yang Qiang , Liu Hao , Zhao Xu , Wang Jiaqi , Jin Meihua , Qi Yuhong
Published: August 2021

Inspired by the antifouling properties of scaly fish, the conventional silicone coating with phenylmethylsilicone oil (PSO/PDMS) composite coating was fabricated and modified with single layer polystyrene (PS) microsphere (PSO/PDMS-PS) arrays. The fish scale like micro-nano structures were fabricated on the surface of bio-inspired coating, which can reduce the contact area with the secreted protein membrane of fouling organisms effectively and prevent further adhesion between fouling organisms and bio-inspired coating. Meanwhile, PSO exuded to the coating surface has the similar function with mucus secreted by fish epidermis, which make the coating surface slithery and will be polished with the fouling organisms in turbulent waters. Compared to PSO/PDMS coating without any structure and conventional silicone coating, PSO/PDMS-PS showed better antiadhesion activity against both marine bacteria and benthic diatom (Navicula sp.). Additionally, the existence of PS microspheres can reduce the release rate of PSO greatly, which will extend the service life of coating. Compared to PSO/PDMS coating, the sustained release efficiency of PSO/PDMS-PS coating can reach 23.2%. This facile method for fabricating the bio-inspired composite slow-release antifouling coating shows a widely fabricating path for the development of synergistic anti-fouling coating.
Towards the Circular Economy of Rare Earth Elements: Lanthanum Leaching from Spent FCC Catalyst by Acids
Authors: Sposato Corradino , Catizzone Enrico , Blasi Alessandro , Forte Marilena , Romanelli Assunta , Morgana Massimo , Braccio Giacobbe , Giordano Girolamo , Migliori Massimo
Published: August 2021

Rare earth elements (REEs) are strategic materials widely used in different applications from Information and Communication Technologies (ICT) to catalysis, which are expected to grow more in the future. In order to reduce the impact of market price and reduce the environmental effect from soil extraction, recovery/purification strategies should be exploited. This paper presents a combined acid-leaching/oxalate precipitation process to recover lanthanum from spent FCC catalyst using nitric acid. Preferred to hydrochloric and sulphuric acid (preliminary assessed), HNO3 showed a good capability to completely leach lanthanum. The combination with an oxalate precipitation step allowed demonstrating that a highly pure (>98% w/w) lanthanum solid can be recovered, with a neglectable amount of poisoning metals (Ni, V) contained into the spent catalyst. This could open a reliable industrial perspective to recover and purify REE in the view of a sustainable recycling strategy.
Integrating Pyrolysis or Combustion with Scrubbing to Maximize the Nutrient and Energy Recovery from Municipal Sewage Sludge
Authors: Saud Ali , Havukainen Jouni , Peltola Petteri , Horttanainen Mika
Published: August 2021

Based on mass and energy balance calculations, this work investigates the possibility of recovering heat and nutrients (nitrogen and phosphorus) from municipal sewage sludge using pyrolysis or combustion in combination with a gas scrubbing technology. Considering a wastewater treatment plant (WWTP) with 65,000 t/a of mechanically dewatered digestate (29% total solids), 550 t/a nitrogen and 500 t/a phosphorus were recovered from the 4900 t/a total nitrogen and 600 t/a total phosphorus that entered the WWTP. Overall, 3600 t/a (73%) of total nitrogen was lost to the air (as N2) and clean water, while 90 t/a (15%) of total phosphorus was lost to clean water released by the WWTP. Both in combustion and in pyrolysis, the nitrogen (3%) released within thermal drying fumes was recovered through condensate stripping and subsequent gas scrubbing, and together with the recovery of nitrogen from WWTP reject water, a total of 3500 t/a of ammonium sulfate fertilizer can be produced. Furthermore, 120 GWh/a of district heat and 9700 t/a of ash with 500 t/a phosphorus were obtained in the combustion scenario and 12,000 t/a of biochar with 500 t/a phosphorus was obtained in the pyrolysis scenario. The addition of a stripper and a scrubber for nitrogen recovery increases the total electricity consumption in both scenarios. According to an approximate cost estimation, combustion and pyrolysis require annual investment costs of 2–4 M EUR/a and 2–3 M EUR/a, respectively, while 3–5 M EUR/a and 3–3.5 M EUR/a will be generated as revenues from the products.
Retooling Medievalism for Early Modern Painting in Annibale Carracci’s Pietà with Saints in Parma
Authors: Stoenescu Livia
Published: August 2021

Annibale Carracci (1560–1609) drew on the Italian Renaissance tradition of the Man of Sorrows to advance the Christological message within the altarpiece context of his Pietà with Saints (1585). From its location at the high altar of the Capuchin church of St. Mary Magdalene in Parma, the work commemorates the life of Duke Alessandro Farnese (1586–1592), who is interred right in front of Annibale’s painted image. The narrative development of the Pietà with Saints transformed the late medieval Lamentation altarpiece focused on the dead Christ into a riveting manifestation of the beautiful and sleeping Christ worshipped by saints and angels in a nocturnal landscape. Thus eschewing historical context, the pictorial thrust of Annibale’s interpretation of the Man of Sorrows attached to the Pietà with Saints was to heighten Eucharistic meaning while allowing for sixteenth-century theological and poetic thought of Mary’s body as the tomb of Christ to cast discriminating devotional overtones on the resting place of the deceased Farnese Duke.
Phytoplankton Bloom Dynamics in the Baltic Sea Using a Consistently Reprocessed Time Series of Multi-Sensor Reflectance and Novel Chlorophyll-a Retrievals
Authors: Brando Vittorio E. , Sammartino Michela , Colella Simone , Bracaglia Marco , Di Cicco Annalisa , D’Alimonte Davide , Kajiyama Tamito , Kaitala Seppo , Attila Jenni
Published: August 2021

A relevant indicator for the eutrophication status in the Baltic Sea is the Chlorophyll-a concentration (Chl-a). Alas, ocean color remote sensing applications to estimate Chl-a in this brackish basin, characterized by large gradients in salinity and dissolved organic matter, are hampered by its optical complexity and atmospheric correction limits. This study presents Chl-a retrieval improvements for a fully reprocessed multi-sensor time series of remote-sensing reflectances (Rrs) at ~1 km spatial resolution for the Baltic Sea. A new ensemble scheme based on multilayer perceptron neural net (MLP) bio-optical algorithms has been implemented to this end. The study documents that this approach outperforms band-ratio algorithms when compared to in situ datasets, reducing the gross overestimates of Chl-a observed in the literature for this basin. The Rrs and Chl-a time series were then exploited for eutrophication monitoring, providing a quantitative description of spring and summer phytoplankton blooms in the Baltic Sea over 1998–2019. The analysis of the phytoplankton dynamics enabled the identification of the latitudinal variations in the spring bloom phenology across the basin, the early blooming in spring in the last two decades, and the description of the spatiotemporal coverage of summer cyanobacterial blooms in the central and southern Baltic Sea.
Evaluation of GRACE/GRACE Follow-On Time-Variable Gravity Field Models for Earthquake Detection above Mw8.0s in Spectral Domain
Authors: Xu Ming , Wan Xiaoyun , Chen Runjing , Wu Yunlong , Wang Wenbing
Published: August 2021

This study compares the Gravity Recovery And Climate Experiment (GRACE)/GRACE Follow-On (GFO) errors with the coseismic gravity variations generated by earthquakes above Mw8.0s that occurred during April 2002~June 2017 and evaluates the influence of monthly model errors on the coseismic signal detection. The results show that the precision of GFO monthly models is approximately 38% higher than that of the GRACE monthly model and all the detected earthquakes have signal-to-noise ratio (SNR) larger than 1.8. The study concludes that the precision of the time-variable gravity fields should be improved by at least one order in order to detect all the coseismic gravity signals of earthquakes with M ≥ 8.0. By comparing the spectral intensity distribution of the GFO stack errors and the 2019 Mw8.0 Peru earthquake, it is found that the precision of the current GFO monthly model meets the requirement to detect the coseismic signal of the earthquake. However, due to the limited time length of the observations and the interference of the hydrological signal, the coseismic signals are, in practice, difficult to extract currently.
Measuring Gas Flaring in Russia with Multispectral VIIRS Nightfire
Authors: Zhizhin Mikhail , Matveev Alexey , Ghosh Tilottama , Hsu Feng-Chi , Howells Martyn , Elvidge Christopher
Published: August 2021

According to the data reported by the international and governmental agencies, the Russian Federation remains one of the world’s major associated petroleum gas (APG) flaring nations. In the past decade, numerous studies have shown the applicability of satellite-based methods to estimate gas flaring. New satellite-based observations might offer an insight in region-, company-, and site-specific gas flaring patterns, as the reported data are often incomplete. We provide a detailed catalog of the upstream and downstream gas flares and an in-depth analysis at the country, region, company and site level of the satellite monitoring results of flaring in Russia from 2012 to 2020. Our analysis is based on the VIIRS Nightfire data and validated against high-resolution daytime satellite images and geographical and geological metadata published by the oil and gas companies and the Russian government. Gas flaring volumes in Russia are estimated to average at 23 billion cubic meters (BCM) annually (15% of global flaring), with 19 BCM (82% on national scale) corresponding to the oil upstream flaring, which has been subject to heavy government regulations since 2013. Despite initially dropping, observed flaring volumes have been on the climb since 2018. We are able to monitor seasonal variations, accidents in gas processing and to track the activities to reduce gas flaring. An effect of gas composition on the flare temperature is reported for oil and gas fields in Russia.
A Forest Monitoring System for Tanzania
Authors: John Elikana , Bunting Pete , Hardy Andy , Silayo Dos Santos , Masunga Edgar
Published: August 2021

Tropical forests provide essential ecosystem services related to human livelihoods. However, the distribution and condition of tropical forests are under significant pressure, causing shrinkage and risking biodiversity loss across the tropics. Tanzania is currently undergoing significant forest cover changes, but monitoring is limited, in part due to a lack of remote sensing knowledge, tools and methods. This study has demonstrated a comprehensive approach to creating a national-scale forest monitoring system using Earth Observation data to inform decision making, policy formulation, and combat biodiversity loss. A systematically wall-to-wall forest baseline was created for 2018 through the application of Landsat 8 imagery. The classification was developed using the extreme gradient boosting (XGBoost) machine-learning algorithm, and achieved an accuracy of 89% and identified 45.76% of the country’s area to be covered with forest. Of those forested areas, 45% was found within nationally protected areas. Utilising an innovative methodology based on a forest habitat suitability analysis, the forest baseline was classified into forest types, with an overall accuracy of 85%. Woodlands (open and closed) were found to make up 79% of Tanzania’s forests. To map changes in forest extent, an automated system for downloading and processing of the Landsat imagery was used along with the XGBoost classifiers trained to define the national forest extent, where Landsat 8 scenes were individually downloaded and processed and the identified changes summarised on an annual basis. Forest loss identified for 2019 was found to be 157,204 hectares, with an overall accuracy of 82%. These forest losses within Tanzania have already triggered ecological problems and alterations in ecosystem types and species loss. Therefore, a forest monitoring system, such as the one presented in this study, will enhance conservation programmes and support efforts to save the last remnants of Tanzania’s pristine forests.
Facile and Electrically Reliable Electroplated Gold Contacts to p-Type InAsSb Bulk-Like Epilayers
Authors: Złotnik Sebastian , Wróbel Jarosław , Boguski Jacek , Nyga Małgorzata , Kojdecki Marek Andrzej , Wróbel Jerzy
Published: August 2021

Narrow band-gap semiconductors, namely ternary InAsSb alloys, find substantial technological importance for mid-infrared application as photodetectors in medical diagnostics or environmental monitoring. Thus, it is crucial to develop electrical contacts for these materials because they are the fundamental blocks of all semiconductor devices. This study demonstrates that electroplated gold contacts can be considered as a simple and reliable metallization technology for the electrical-response examination of a test structure. Unalloyed electroplated Au contacts to InAsSb exhibit specific contact resistivity even lower than vacuum-deposited standard Ti–Au. Moreover, temperature-dependent transport properties, such as Hall carrier concentration and mobility, show similar trends, with a minor shift in the transition temperature. It can be associated with a difference in metallization technology, mainly the presence of a Ti interlayer in vacuum-deposited contacts. Such a transition may give insight into not only the gentle balance changes between conductivity channels but also an impression of changing the dominance of carrier type from p- to n-type. The magnetotransport experiments assisted with mobility spectrum analysis clearly show that such an interpretation is incorrect. InAsSb layers are strongly p-type dominant, with a clear contribution from valence band carriers observed at the whole analyzed temperature range. Furthermore, the presence of thermally activated band electrons is detected at temperatures higher than 220 K.
Wearable Urban Mobility Assistive Device for Visually Impaired Pedestrians Using a Smartphone and a Tactile-Foot Interface
Authors: Tachiquin Ricardo , Velázquez Ramiro , Del-Valle-Soto Carolina , Gutiérrez Carlos A. , Carrasco Miguel , De Fazio Roberto , Trujillo-León Andrés , Visconti Paolo , Vidal-Verdú Fernando
Published: August 2021

This paper reports on the progress of a wearable assistive technology (AT) device designed to enhance the independent, safe, and efficient mobility of blind and visually impaired pedestrians in outdoor environments. Such device exploits the smartphone’s positioning and computing capabilities to locate and guide users along urban settings. The necessary navigation instructions to reach a destination are encoded as vibrating patterns which are conveyed to the user via a foot-placed tactile interface. To determine the performance of the proposed AT device, two user experiments were conducted. The first one requested a group of 20 voluntary normally sighted subjects to recognize the feedback provided by the tactile-foot interface. The results showed recognition rates over 93%. The second experiment involved two blind voluntary subjects which were assisted to find target destinations along public urban pathways. Results show that the subjects successfully accomplished the task and suggest that blind and visually impaired pedestrians might find the AT device and its concept approach useful, friendly, fast to master, and easy to use.
A Soft Haptic Glove Actuated with Shape Memory Alloy and Flexible Stretch Sensors
Authors: Terrile Silvia , Miguelañez Jesus , Barrientos Antonio
Published: August 2021

Haptic technology allows us to experience tactile and force sensations without the need to expose ourselves to specific environments. It also allows a more immersive experience with virtual reality devices. This paper presents the development of a soft haptic glove for kinesthetic perception. It is lightweight and soft to allow for a more natural hand movement. This prototype actuates two fingers with two shape memory alloy (SMA) springs. Finite element (FE) simulations of the spring have been carried out to set the dimensions of the actuators. Flexible stretch sensors provide feedback to the system to calculate the tension of the cables attached to the fingers. The control can generate several recognizable levels of force for any hand position since the objects to be picked up can vary in weight and dimension. The glove can generate three levels of force (100, 200 and 300 g) to evaluate more easily the proper functioning. We realized tests on 15 volunteers simulating forces in various order after a quick training. We also asked volunteers about the experience for comfort, global experience and simplicity). Results were satisfactory in both aspects: the glove fulfilled its function, and the users were comfortable with it.
A Dictionary Optimization Method for Reconstruction of ECG Signals after Compressed Sensing
Authors: De Vito Luca , Picariello Enrico , Picariello Francesco , Rapuano Sergio , Tudosa Ioan
Published: August 2021

This paper presents a new approach for the optimization of a dictionary used in ECG signal compression and reconstruction systems, based on Compressed Sensing (CS). Alternatively to fully data driven methods, which learn the dictionary from the training data, the proposed approach uses an over complete wavelet dictionary, which is then reduced by means of a training phase. Moreover, the alignment of the frames according to the position of the R-peak is proposed, such that the dictionary optimization can exploit the different scaling features of the ECG waves. Therefore, at first, a training phase is performed in order to optimize the overcomplete dictionary matrix by reducing its number of columns. Then, the optimized matrix is used in combination with a dynamic sensing matrix to compress and reconstruct the ECG waveform. In this paper, the mathematical formulation of the patient-specific optimization is presented and three optimization algorithms have been evaluated. For each of them, an experimental tuning of the convergence parameter is carried out, in order to ensure that the algorithm can work in its most suitable conditions. The performance of each considered algorithm is evaluated by assessing the Percentage of Root-mean-squared Difference (PRD) and compared with the state of the art techniques. The obtained experimental results demonstrate that: (i) the utilization of an optimized dictionary matrix allows a better performance to be reached in the reconstruction quality of the ECG signals when compared with other methods, (ii) the regularization parameters of the optimization algorithms should be properly tuned to achieve the best reconstruction results, and (iii) the Multiple Orthogonal Matching Pursuit (M-OMP) algorithm is the better suited algorithm among those examined.
Detection of Diabetic Eye Disease from Retinal Images Using a Deep Learning Based CenterNet Model
Authors: Nazir Tahira , Nawaz Marriam , Rashid Junaid , Mahum Rabbia , Masood Momina , Mehmood Awais , Ali Farooq , Kim Jungeun , Kwon Hyuk-Yoon , Hussain Amir
Published: August 2021

Diabetic retinopathy (DR) is an eye disease that alters the blood vessels of a person suffering from diabetes. Diabetic macular edema (DME) occurs when DR affects the macula, which causes fluid accumulation in the macula. Efficient screening systems require experts to manually analyze images to recognize diseases. However, due to the challenging nature of the screening method and lack of trained human resources, devising effective screening-oriented treatment is an expensive task. Automated systems are trying to cope with these challenges; however, these methods do not generalize well to multiple diseases and real-world scenarios. To solve the aforementioned issues, we propose a new method comprising two main steps. The first involves dataset preparation and feature extraction and the other relates to improving a custom deep learning based CenterNet model trained for eye disease classification. Initially, we generate annotations for suspected samples to locate the precise region of interest, while the other part of the proposed solution trains the Center Net model over annotated images. Specifically, we use DenseNet-100 as a feature extraction method on which the one-stage detector, CenterNet, is employed to localize and classify the disease lesions. We evaluated our method over challenging datasets, namely, APTOS-2019 and IDRiD, and attained average accuracy of 97.93% and 98.10%, respectively. We also performed cross-dataset validation with benchmark EYEPACS and Diaretdb1 datasets. Both qualitative and quantitative results demonstrate that our proposed approach outperforms state-of-the-art methods due to more effective localization power of CenterNet, as it can easily recognize small lesions and deal with over-fitted training data. Our proposed framework is proficient in correctly locating and classifying disease lesions. In comparison to existing DR and DME classification approaches, our method can extract representative key points from low-intensity and noisy images and accurately classify them. Hence our approach can play an important role in automated detection and recognition of DR and DME lesions.
Design of Smart Steering Wheel for Unobtrusive Health and Drowsiness Monitoring
Authors: Babusiak Branko , Hajducik Adrian , Medvecky Stefan , Lukac Michal , Klarak Jaromir
Published: August 2021

This article describes the design of a smart steering wheel intended for use in unobtrusive health and drowsiness monitoring. The aging population, cardiovascular disease, personalized medicine, and driver fatigue were significant motivations for developing a monitoring platform in cars because people spent much time in cars. The purpose was to create a unique, comprehensive monitoring system for the driver. The crucial parameters in health or drowsiness monitoring, such as heart rate, heart rate variability, and blood oxygenation, are measured by an electrocardiograph and oximeter integrated into the steering wheel. In addition, an inertial unit was integrated into the steering wheel to record and analyze the movement patterns performed by the driver while driving. The developed steering wheel was tested under laboratory and real-life conditions. The measured signals were verified by commercial devices to confirm data correctness and accuracy. The resulting signals show the applicability of the developed platform in further detecting specific cardiovascular diseases (especially atrial fibrillation) and drowsiness.