bluuebunny/crossref_metadata_2025 huggingface dataset:
Pro-Environmental Behaviour in the European Union Countries
Authors: Mikuła Aneta , Raczkowska Małgorzata , Utzig Monika
Published: September 2021

The purpose of the presented research is to assess pro-environmental behaviour (PEB) in European Union countries in 2009 and 2019. The study used a synthetic measure developed using the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) benchmark method. This method enables distinguishing classes and ranks of countries depending on the adopted characteristics. Basic measures of descriptive statistics, i.e., average, standard deviation and the coefficient of variation, were used in the analysis of the data set. The main research question addressed in this study concerns the relationship between the level of PEB and economic, demographic, and educational factors—not only on a micro scale but also from the macroeconomic perspective. The research has revealed a wide variety throughout the European Union (EU-27) countries in terms of pro-environmental behaviour. Sweden, Finland, and Denmark top the ranking, while Malta, Greece, Spain, and Romania are at the bottom of it. Northern European countries can therefore be identified as a group that represents a positive benchmark in terms of PEB across the European Union (EU-27). The correlation between PEB and selected economic, demographic, and education-related variables was also investigated. Country-level PEB is correlated with demographic and economic variables, but it is not correlated with education-related variables.
The Spatial Pattern of the Upper Limit of Montane Deciduous Broad-Leaved Forests and Its Geographical Interpretation in the East Monsoon Realm of China
Authors: Wang Jing , Zhang Baiping , Yao Yonghui
Published: September 2021

Montane deciduous broad-leaved forests (MDB) are mainly distributed in the east monsoon realm of China. The upper limit of MDB significantly varies from mountain to mountain. However, the spatial pattern of the upper limit of MDB and its underlying drivers are still unknown. In this study, we conducted hierarchical multiple regression to quantify the effect of climatic factors, peak elevation, and cold tolerance of dominant species on the geographical distribution of the upper limit of MDB on 75 mountains in the east monsoon realm of China. The results show that: (1) the upper limit of MDB in the east monsoon realm of China, 2800 m, is the highest in Taibai peak of the Qinling mountain ranges, from where it tends to decrease both northward and southward. (2) The upper limit of MDB on the mountains with climatic treeline is mainly affected by climatic factors, the minimum temperature of the coldest month (MinT), and the precipitation seasonality (PS), with an R2 of 0.733. (3) The upper limit of MDB on both temperate and subtropical mountains without climatic treeline is affected by MinT, PS, peak elevation, and cold tolerance of dominant species together, with an R2 of 0.793 and 0.748, respectively. (4) The dominant species of the upper limit of MDB significantly differ temperate and subtropical ranges, the former of which is mainly in the genus Betula, and the latter of which is in the genus Quercus. The upper limit of MDB with the genus Fagus as dominant species is only distributed in the mountains towards the south of the Qinling mountain ranges. (5) The warmth index (WI) at the upper limit of deciduous broad-leaved forest on the mountains with climatic treeline is about 60 °C month, which is lower than that at the northernmost boundary of the latitudinal distributed deciduous broad-leaved forest (90 °C month). Our study revealed the spatial pattern and geographical drivers of the upper limit of MDB, improved our understanding of differences in MDB vegetation among different mountain ranges, and provided climatic correlates for predicting the dynamics of the upper limit of MDB under climate change.
Site-Effects Dominate the Plant Availability of Nutrients under Salix Species during the First Cutting Cycle
Authors: Koczorski Piotr , Furtado Bliss , Hrynkiewicz Katarzyna , Breezmann Michelle , Weih Martin , Baum Christel
Published: September 2021

Fast-growing willows (Salix spp.) provide alternative sources of renewable energy generation, but need an adequate nutrient availability in the soil for high biomass production. In general, species mixtures can be more nutrient-efficient than pure cultures, but this is scarcely known for Salix spp. Therefore, this study evaluates the nutrient availability and P mobilization under two willow species, Salixdasyclados var. ‘Loden’ and S. schwerinii × viminalis var. ‘Tora’, grown as pure and mixed cultures at non-fertilized former arable sites in Germany (Stagnic Cambisol) and Sweden (Vertic Cambisol). The plant availability of potassium (K), magnesium (Mg) and phosphorus (P) and soil phosphatase activities in the topsoil were measured in spring of the year of planting (initial) and under 4 years-old stocks (one year after the first 3-year cutting cycle). The initial plant availability of the nutrients significantly differed between the sites and the two sampling dates at both sites. The plant availability of K and Mg was optimal to high at both sites and sampling dates, but rather low for P (after 4 years ≤5 mg P 100 g−1 soil). The plant-available P and K content in soil significantly decreased within the 4 years of willow growth at both sites. The acid and alkaline phosphatase activity in the soil of the German site (Rostock) was significantly lower after 4 years of willow growth, but differed not significantly between the two sampling dates at the Swedish site (Uppsala). Higher activity of acid phosphatase compared to alkaline phosphatase was recorded in the soils at both test sites based on the site-specific soil pH (<7). The slight decrease of plant availability of P after 4 years of Salix growth in pure culture differed not significantly between the different species. Mixed growth did not decrease the plant availability of P within this period, although no significant difference in the biomass production of pure and mixed growth was observed. This was valid at both sites, and therefore, seems independent of the site-specific differences in soil and climate conditions. The general validity of the assumptions should be tested also for other species mixtures and soil conditions in the future before site-adapted growth designs can be recommended in biomass production of Salix.
Evaluating the Influence of Climate Change on Sophora moorcroftiana (Benth.) Baker Habitat Distribution on the Tibetan Plateau Using Maximum Entropy Model
Authors: Xin Fumei , Liu Jiming , Chang Chen , Wang Yuting , Jia Liming
Published: September 2021

The ecosystems across the Tibetan Plateau are changing rapidly in response to climate change, which poses unprecedented challenges for the control and mitigation of desertification on the Tibetan Plateau. Sophora moorcroftiana (Benth.) Baker is a drought-resistant plant species that has great potential to be used for desertification and soil degradation control on the Tibetan Plateau. In this study, using a maximum entropy (MaxEnt) niche model, we characterized the habitat distribution of S. moorcroftiana on the Tibetan Plateau under both current and future climate scenarios. To construct a robust model, 242 population occurrence records, gathered from our field surveys, historical data records, and a literature review, were used to calibrate the MaxEnt model. Our results showed that, under current environmental conditions, the habitat of S. moorcroftiana was concentrated in regions along the Yarlung Tsangpo, Lancang, and Jinsha rivers on the Tibetan Plateau. Elevation, isothermality, and minimal air temperature of the coldest month played a dominant role in determining the habitat distribution of S. moorcroftiana. Under future climate scenarios, the increased air temperature was likely to benefit the expansion of S. moorcroftiana over the short term, but, in the long run, continued warming may restrict the growth of S. moorcroftiana and lead to a contraction in its habitat. Importantly, the Yarlung Tsangpo River valley was found to be the core habitat of S. moorcroftiana, and this habitat moved westwards along the Yarlung Tsangpo River under future climate scenarios, but did not detach from it. This finding suggests that, with the current pace of climate change, an increase in efforts to protect and cultivate S. moorcroftiana is necessary and critical to control desertification on the Tibetan Plateau.
Controllability for Fuzzy Fractional Evolution Equations in Credibility Space
Authors: Niazi Azmat Ullah Khan , Iqbal Naveed , Shah Rasool , Wannalookkhee Fongchan , Nonlaopon Kamsing
Published: September 2021

This article addresses exact controllability for Caputo fuzzy fractional evolution equations in the credibility space from the perspective of the Liu process. The class or problems considered here are Caputo fuzzy differential equations with Caputo derivatives of order β∈(1,2), 0CDtβu(t,ζ)=Au(t,ζ)+f(t,u(t,ζ))dCt+Bx(t)Cx(t)dt with initial conditions u(0)=u0,u′(0)=u1, where u(t,ζ) takes values from U(⊂EN),V(⊂EN) is the other bounded space, and EN represents the set of all upper semi-continuously convex fuzzy numbers on R. In addition, several numerical solutions have been provided to verify the correctness and effectiveness of the main result. Finally, an example is given, which expresses the fuzzy fractional differential equations.
Analytic Fuzzy Formulation of a Time-Fractional Fornberg–Whitham Model with Power and Mittag–Leffler Kernels
Authors: Rashid Saima , Ashraf Rehana , Akdemir Ahmet Ocak , Alqudah Manar A. , Abdeljawad Thabet , Mohamed Mohamed S.
Published: September 2021

This manuscript assesses a semi-analytical method in connection with a new hybrid fuzzy integral transform and the Adomian decomposition method via the notion of fuzziness known as the Elzaki Adomian decomposition method (briefly, EADM). Moreover, we use the aforesaid strategy to address the time-fractional Fornberg–Whitham equation (FWE) under gH-differentiability by employing different initial conditions (IC). Several algebraic aspects of the fuzzy Caputo fractional derivative (CFD) and fuzzy Atangana–Baleanu (AB) fractional derivative operator in the Caputo sense, with respect to the Elzaki transform, are presented to validate their utilities. Apart from that, a general algorithm for fuzzy Caputo and AB fractional derivatives in the Caputo sense is proposed. Some illustrative cases are demonstrated to understand the algorithmic approach of FWE. Taking into consideration the uncertainty parameter ζ∈[0,1] and various fractional orders, the convergence and error analysis are reported by graphical representations of FWE that have close harmony with the closed form solutions. It is worth mentioning that the projected approach to fuzziness is to verify the supremacy and reliability of configuring numerical solutions to nonlinear fuzzy fractional partial differential equations arising in physical and complex structures.
Inadequate Cerebrospinal Fluid Concentrations of Available Salvage Agents Further Impedes the Optimal Treatment of Multidrug-Resistant Enterococcus faecium Meningitis and Bacteremia
Authors: Wenzler Eric , Adeel Alina , Wu Tiffany , Jurkovic Michele , Walder Jeremy , Ramasra Emily , Campion Maureen , Cerny Jan , Theodoropoulos Nicole M.
Published: September 2021

Background: Vancomycin-resistant Enterococcus faecium (VRE) in particular has evolved as an important cause of hospital acquired infection, especially in immunocompromised hosts. Methods: We present a complex case of a patient with relapsed acute myeloid leukemia who underwent allogenic hematopoietic stem cell transplantation complicated by persistent VRE bacteremia and meningitis. To optimize therapy, various blood and cerebrospinal fluid (CSF) samples were sent to a research laboratory for extensive susceptibility testing, pharmacokinetic analyses, and time-kill experiments. Results: In vitro testing revealed resistance to all first-line treatment options and CSF sampling demonstrated sub-optimal central nervous system concentrations achieved by each antimicrobial agent administered in relation to their respective MIC value. Time-kill analyses at observed CSF concentrations confirmed the lack of bactericidal activity despite use of a four-drug combination regimen. Conclusions: This work is the first to report CSF concentrations of oritavancin and tedizolid in humans and adds to the limited data regarding in vitro susceptibility of new antimicrobial agents such as eravacycline, omadacycline, and lefamulin against VRE. Our study provides new insights into various aspects of treatment of extensively drug-resistant Enterococcus faecium meningitis and bacteremia and supports the continued pursuit of precision medicine for these challenging cases.
Can Live Streaming Save the Tourism Industry from a Pandemic? A Study of Social Media
Authors: Qiu Qihang , Zuo Yifan , Zhang Mu
Published: September 2021

As a reflection of shifting and fluid experiences in time and space, live streaming can reduce losses in the tourism industry associated with travel restrictions during the COVID-19 pandemic. Compared with the use of live streaming activities in entertainment, shopping, sport, e-sport, religious, educational, and academic settings, the tourism context has yet to be explored. This study takes China as a case to examine tourism practices related to live streaming. Specifically, 48,114 social media posts were subjected to systematic content analysis. The dataset contained live streaming content related to 147 countries and 34 Chinese provincial administrative regions between 2010 and 2021. Findings revealed the following: (1) the development of tourism live streaming in China can be classified into germination, exploration, and opportunity stages; (2) live content mainly evoked positive emotions, whereas negative sentiment resulted from illegal or boring content; (3) users’ perceptions of tourism live streaming content involved institutions, live streaming tools, live streaming attractions, the live streaming economy, people, facilities and information, time, and regions; and (4) live streaming tools and attractions constituted the core of the identified semantic network and had the strongest regulation capabilities in tourism live streaming activities. Findings shed light on latent cultural meanings in social media communications, where tourism live streaming features high-frequency linguistic signs.
The Geranium Platform: A KG-Based System for Academic Publications
Authors: Garifo Giovanni , Futia Giuseppe , Vetrò Antonio , De Martin Juan Carlos
Published: September 2021

Knowledge Graphs (KGs) have emerged as a core technology for incorporating human knowledge because of their capability to capture the relational dimension of information and of its semantic properties. The nature of KGs meets one of the vocational pursuits of academic institutions, which is sharing their intellectual output, especially publications. In this paper, we describe and make available the Polito Knowledge Graph (PKG) –which semantically connects information on more than 23,000 publications and 34,000 authors– and Geranium, a semantic platform that leverages the properties of the PKG to offer advanced services for search and exploration. In particular, we describe the Geranium recommendation system, which exploits Graph Neural Networks (GNNs) to suggest collaboration opportunities between researchers of different disciplines. This work integrates the state of the art because we use data from a real application in the scholarly domain, while the current literature still explores the combination of KGs and GNNs in a prototypal context using synthetic data. The results shows that the fusion of these technologies represents a promising approach for recommendation and metadata inference in the scholarly domain.
Fatty Acids Present in Wheat Kernels Influence the Development of the Grain Weevil (Sitophilus granarius L.)
Authors: Nietupski Mariusz , Ludwiczak Emilia , Cabaj Robert , Purwin Cezary , Kordan Bożena
Published: September 2021

Sitophilus granarius (L.) is considered to be one of the major pests causing damage to cereal grain stored in silos and granaries. Using traditional methods (synthetic insecticides, mechanical, or physical methods) to control this pest is either ineffective or dangerous to people and nature. It is, therefore, necessary to develop new cultivars of cereals that will be distinguished by a high natural tolerance of the foraging by S. granarius. The aim of this study is expressed in the set research hypothesis, stating that the number of offspring of the grain weevil on stored wheat kernels can depend on the content of fatty acids in the kernels. Thus, the qualitative and quantitative composition of fatty acids was determined in kernels of 10 winter wheat cultivars, and the abundance of the beetle’s offspring generation of S. granarius that developed on the wheat grain, as well as the mass of produced dust and loss in the mass of wheat grain were determined. By applying statistical analyses (GLM, ANOVA, Pearson’s linear correlation coefficient, and analysis of redundancy), the presence and character of the dependence between the determined content of fatty acids in wheat grain and the factors describing the development of S. granarius were established. The research results indicate that fatty acids from the groups C 18:1 and C 20:1 probably play an important role as substances stimulating the increase in the number of the tested pest progeny. In contrast, fatty acids C 15:0, C 16:1, and C 18:3, which were determined in large amounts in the grain of wheat cultivars Speedway, KWS Livius, and Julius, can reduce the number of offspring of pest insect.
Assessing mPTC Progression during Active Surveillance: Volume or Diameter Increase?
Authors: Campopiano Maria Cristina , Matrone Antonio , Rago Teresa , Scutari Maria , Prete Alessandro , Agate Laura , Piaggi Paolo , Elisei Rossella , Molinaro Eleonora
Published: September 2021

Active surveillance (AS) is considered an alternative to immediate surgery in micropapillary thyroid carcinoma (mPTC). However, the definition of clinical mPTC progression during AS is controversial. We evaluated changes in tumor size using both tumor diameters and volume in 109 patients with mPTC followed in an AS protocol for a mean period of 31 ± 18 months. At the time of data lock, 19/109 (17.4%) mPTC reached and maintained a volume increase of ≥50%. However, only 3/19 (15.7%) showed progression, according to the diameter increase. The remaining 16 showed a slight diameter growth without reaching the original protocol progression criteria. The mean mPTC growth rate in stable cases was 0.37 mm3/month, while it was significantly greater in the mPTC, which achieved a volume change ≥50% with respect to the other. The two mPTC that developed a significant diameter increase had a growth rate of 41 and 18 mm3/month. Instead, the growth rates of the three mPTC that developed lymph node metastases were 0, 2.5 and 16 mm3/month. The ≥50% volume increase appears to be a too sensitive marker of disease progression, with a downstream higher surgery rate. The assessment of growth rate could distinguish mPTC with high and low growth rates, which would allow us to tailor the algorithm of the evaluations to a more appropriate timing.
Inter-Individual Variation and Cardioprotection in Anthracycline-Induced Heart Failure
Authors: Norton Nadine , Weil Raegan M. , Advani Pooja P.
Published: September 2021

Anthracyclines are one of the most widely used and effective chemotherapies in oncology, but their most important side effect is the cumulative, dose-related cardiotoxicity leading to congestive heart failure in ~5% of individuals. Methodology and pharmacogenetic studies for predicting which individuals are at high risk and subsequently the development of targeted and individualized cardioprotective plans are beginning to make progress. Here, we review current putative risk genes and variants, the strength of evidence for each genetic association and the interaction between risk genes, in the context of known clinical risk factors and potential novel cardioprotective strategies.
Evaluating Territorial Targets of European Integrated Urban Policy. The URBAN and URBANA Initiatives in Spain (1994–2013)
Authors: Fernández-García Manuel , Navarro Clemente J. , Gómez-Ramirez Irene
Published: September 2021

Since the 1990s, the EU has promoted urban integrated programmes in vulnerable urban areas, combining top-down and bottom-up approaches to select the target areas. The bottom-up approach refers to selecting disadvantaged areas by municipalities, and the top-down approach deals with the eligibility criteria established by programmes. However, the level of compliance with these criteria among the areas selected is not usually evaluated. This study proposes a research strategy and analyses the URBAN and URBANA Initiatives in Spain (1994–2013). The objective is to evaluate the adequacy of selected areas through a methodology (effect size analysis) that assesses the level of vulnerability of urban areas defined in each city according to the criteria specified by the calls for proposals of the different urban regeneration programmes. According to the existing literature on the subject, a good selection of territorial targets is a fundamental element in the success of area-based interventions. The principal findings are that selected areas meet eligibility criteria, especially as regards urban fabric and unemployment. This article’s main contribution is to show that effect size analysis is an easy method to evaluate target selection in area-based policies from a methodological perspective. Together with centred measures of eligibility criteria (indicators), this methodological approach allows for comparisons between and within programmes and can be helpful to both practitioners or policy analysis scholars.
Geodesign Experiments in Areas of Social Vulnerability in the Iron Quadrangle, Minas Gerais, Brazil
Authors: Moura Ana Clara Mourão , Zyngier Camila Marques , Sena Ítalo Sousa , Freitas Vanessa Tenuta
Published: September 2021

This paper presents and discusses the use of methodologies for shared and participatory planning through Geodesign, in areas of irregular occupation and social vulnerability in the urban areas of the Iron Quadrangle, Minas Gerais, Brazil. It is illustrated by the development of four case studies with varying degrees of complexity, participation, and impact as a support for opinion building or decision making. The work encompasses different applications of digital support platforms, from web-based to off-line, as well as their methodological variations, adopted according to the goals of each case study. They vary according to space, the profile of the participants (ages), technological platform, methodological steps, but they all share support for opinion making. We conclude by suggesting optimal methodological choices for different contexts of social vulnerability, regarding the evolution of urban planning processes. We argue in favor of Geodesign as a framework for the planning of irregular housing occupations, as it is flexible enough to deal with different scenarios.
Radiologist Checklist for Selecting Patients to Undergo PIPAC (Pressurized IntraPeritoneal Aerosol Chemotherapy)
Authors: Rodolfino Elena , Di Marco Margo’ , Ilot Alessia , Iezzi Roberto , Gui Benedetta , Avesani Giacomo , Panico Camilla , Strippoli Antonia , Di Giorgio Andrea , Pacelli Fabio , Manfredi Riccardo
Published: September 2021

Peritoneal carcinomatosis frequently occurs in advanced gastrointestinal and gynecological cancers. As factors such as poor drug uptake and distribution cause chemotherapy to be less effective, alternative therapies have been explored. Introduced in 2013, PIPAC (pressurized intraperitoneal aerosol chemotherapy) uses aerosolized chemotherapeutics sprayed into the patient’s peritoneal cavity using a laparoscopic approach. Despite the literature showing encouraging data regarding the tolerability and efficacy of PIPAC, there is a lack of articles on the role that imaging plays in selecting patients suitable for PIPAC. The aim of this study is to combine literature-based evidence and clinical experience to provide information able to support training radiologists, as well as experienced radiologists interested in innovative therapies.
Preparation and Properties of Waterborne Polypyrrole/Cement Composites
Authors: Feng Chao , Huang Jiaxing , Yan Peihui , Wan Fei , Zhu Yunfei , Cheng Hao
Published: September 2021

The electrical properties of cement are gaining importance for the application in building construction. Polypyrrole (PPy) has been widely applied in most fields because of its excellent conductivity performance, environmental friendliness, easy fabrication, and other specialties. These features made them useful for self-sensing applications. In this work, waterborne polypyrrole (WPPy) was prepared via the chemical oxidative polymerization with three kinds of hydrophilic agents: sodium lignosulfonate (LGS), sodium dodecyl sulfonate (SDS), and sodium dodecyl sulfate (SLS), and then WPPy/cement composites were prepared by mixing cement with it. The contact angle, conductivity, and microstructure of WPPy were characterized by contact angle tester, four-point probes, and SEM. The composition, microstructure, and properties of WPPy/cement composites were characterized by FTIR, TGA, XRD, and SEM. The content of LGS was 40 wt%, WPPy got the optimal comprehensive performance, the conductivity was 15.06 times of the control sample and the contact angle was reduced by 69.95%. SEM analysis showed that hydrophilic agent content had great effect on the particle size of WPPy, the average diameter of WPPy particles decreased from 200 nm to 50 nm with the increase of LGS content. The results also showed that the adding of WPPy in WPPy/cement composites can significantly improve the conductivity and compactness, optimize the microstructure of cement composite. When the content of WPPy was 1.25 wt%, WPPy/cement composite showed the lowest resistivity and saturated water content of cement composite was 8 wt%. In addition, it could also inhibit the formation of Ca(OH)2 in the early hydration process.
The Influence of Zero Shear Viscosity of TLA-Modified Binder and Mastic Composition on the Permanent Deformation Resistance of Mastic Asphalt Mixture
Authors: Kołodziej Krzysztof , Bichajło Lesław , Siwowski Tomasz
Published: September 2021

Mastic asphalt (MA) has been particularly popular in recent years for bridge pavements due to many advantages such as easy application, good waterproofing properties, and high durability. However, the drawback of mastic asphalt in comparison to other asphalt mixtures is its lower resistance to permanent deformation. Trinidad Lake Asphalt (TLA) is often applied to make mastic asphalt resistant to permanent deformation. Practical experience demonstrates that serious failures may occur if MA pavement design and materials selection is not taken into account sufficiently. Therefore in this study, the influence of two parameters: zero shear viscosity (ZSV) of TLA-modified binder and mastic composition described by the filler–binder ratio, on the permanent deformation resistance of the MA mixture was evaluated. The primary purpose of determining the ZSV of the TLA-modified binders was to evaluate the rutting potential of the binders. The permanent deformation (rutting) resistance of the MA mixtures was evaluated based on static and dynamic indentation tests. The optimum content of TLA in the base bitumen and the optimum filler–binder ratio in the MA mixture were obtained based on multiple performance evaluations for modified binder, mastic and MA mixtures, i.e., 20% and 4.0, respectively.
Flame Retardancy Properties and Physicochemical Characteristics of Polyurea-Based Coatings Containing Flame Retardants Based on Aluminum Hydroxide, Resorcinol Bis(Diphenyl Phosphate), and Tris Chloropropyl Phosphate
Authors: Dukarski Wojciech , Krzyżanowski Piotr , Gonsior Marcin , Rykowska Iwona
Published: September 2021

Polyurea is a synthetic material made by the reaction of isocyanate and polymer blend-containing amines. Due to its outstanding mechanical properties and fast curing, polyurea-based coatings have found dozens of applications, including waterproofing and anti-corrosion coatings. Further development of this material can create a flame-retardant product, a good alternative for common products available on the market, such as intumescent coatings. To improve the flame retardancy of polyurea, several flame retardants were investigated. The influence of aluminum hydroxide, resorcinol bis(diphenyl phosphate) (RDP), and tris chloropropyl phosphate (TCPP) on flame retardancy and morphology was studied. The following methods were used: infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, limiting oxygen index, and tensile strength. The examinations mentioned above showed the improvement of flame-retardancy of polyurea for two products: chlorinated organophosphate and organophosphate. Nevertheless, using the chlorinated organophosphate additive caused a rapid deterioration of mechanical properties.
Compatibility Tests between Three Commercially Available Organic PCMs and Metals Typically Used in Fin-and-Tube Heat Exchangers
Authors: Rolka Paulina , Karwacki Jaroslaw , Jaworski Maciej
Published: September 2021

Energy storage is one of the most effective ways to increase energy savings and efficiency of heating and air conditioning systems. Phase change materials (PCMs) are increasingly used in latent heat thermal energy storage (LHTES) systems to increase their capacity. In such systems, costs are a very important factor of viability so the typical heat transfer elements like fin-and-tube heat exchangers are used to construct the LHTES. The problem of this approach is a possibility of corrosion of metals in contact with PCM that shortens the life cycle of LHTES. Therefore, the main objective of this work is an experimental study of the compatibility of metals typically used in fin-and-tube heat exchangers (copper and aluminum) with three commercially available organic PCMs (RT15, RT18HC, and RT22HC). Compatibility of PCMs with copper and aluminum was tested for a period of approximately two months, during which a total of 35 heating and cooling cycles were carried out, each with a complete phase transition of the tested materials. In the course of the tests it was assessed whether the PCM caused corrosion of the tested metals. The evaluation was based on the gravimetric method, calculation of corrosion rate, and visual observations and measurements of the features on the metal sample’s surface using optical microscope. It was determined that RT15, RT18 HC, and RT22 HC show low corrosion rates for aluminum and copper samples. The visual tests indicate that there was no change in the PCM solutions during the tests, only a sediment was observed for the samples with the combination of copper and aluminum. Microscopic examination of the surface of the samples did not show any significant surface changes, except for the aluminum samples, on the surface of which local microdefects were observed. It follows from the present results that copper and aluminum can be used to design the heat transfer surface in contact with the chosen PCMs.
Therapeutic Efficacy of Artificial Skin Produced by 3D Bioprinting
Authors: Jang Kwang-Sik , Park Soon-Jung , Choi Jong-Jin , Kim Ha-Na , Shim Kyung-Mi , Kim Mi-Jeong , Jang Il-Ho , Jin Song-Wan , Kang Seong-Soo , Kim Se-Eun , Moon Sung-Hwan
Published: September 2021

The skin protects the body from external barriers. Certain limitations exist in the development of technologies to rapidly prepare skin substitutes that are therapeutically effective in surgeries involving extensive burns and skin transplantation. Herein, we fabricated a structure similar to the skin layer by using skin-derived decellularized extracellular matrix (dECM) with bioink, keratinocytes, and fibroblasts using 3D-printing technology. The therapeutic effects of the produced skin were analyzed using a chimney model that mimicked the human wound-healing process. The 3D-printed skin substitutes exhibited rapid re-epithelialization and superior tissue regeneration effects compared to the control group. These results are expected to aid the development of technologies that can provide customized skin-replacement tissues produced easily and quickly via 3D-printing technology to patients.
Experimental Investigation on the Shear Behaviour of Stud-Bolt Connectors of Steel-Concrete-Steel Fibre-Reinforced Recycled Aggregates Sandwich Panels
Authors: Karimipour Arash , Ghalehnovi Mansour , Golmohammadi Mohammad , de Brito Jorge
Published: September 2021

Steel-concrete-steel (SCS) sandwich panels are manufactured with two thin high-strength steel plates and a moderately low-density and low-strength thick concrete core. In this study, 24 specimens were produced and tested. In these specimens, a new stud-bolt connector was used to regulate its shear behaviour in sandwich panels. The bolts’ diameter, concrete core’s thickness and bolts’ spacing were the parameters under analysis. Furthermore, the concrete core was manufactured with normal-strength concrete and steel fibres concrete (SFC). Steel fibres were added at 1% by volume. In addition, the recycled coarse aggregate was used at 100% in terms of mass instead of natural coarse aggregate. Therefore, the ultimate bearing capability and slip of the sandwich panels were recorded, and the failure mode and ductility index of the specimens were evaluated. A new formula was also established to determine the shear strength of SCS panels with this kind of connectors. According to this study, increasing the diameter of the stud-bolts or using SFC in sandwich panels improve their shear strength and ductility ratio.
Modification of Mechanical Properties in Directed Energy Deposition by a Static Magnetic Field: Experimental and Theoretical Analysis
Authors: Filimonov Aleksandr M. , Rogozin Oleg A. , Dubinin Oleg N. , Kuzminova Yulia O. , Shibalova Anastasia A. , Okulov Ilya V. , Akhatov Iskander S. , Evlashin Stanislav A.
Published: September 2021

The superimposed magnetic field affects the microstructure and mechanical properties of additively manufactured metal parts. In this work, the samples were fabricated from Inconel 718 superalloy by directed energy deposition under a 0.2 T static field. The magnetohydrodynamic 1D model is proposed for the estimation of a fluid flow inside a molten pool. According to the theoretical predictions, the fluid flow is slightly decreased by an applied field. The estimated thermoelectric magnetic convection in the mushy zone is shown to be negligible to change in subgrain size, but enough to reduce the hard-to-dissolve Nb-rich phase, thereby improving the average ultimate elongation from 23% to 27%. The obtained results confirm that an external static magnetic field can modify and enhance the mechanical properties of additively manufactured materials.
Precision Rock Excavation: Beyond Controlled Blasting and Line Drilling
Authors: Cardu Marilena , Saltarin Simone , Todaro Carmine , Deangeli Chiara
Published: September 2021

The strictness of the result of an excavation, whether mechanical or by means of explosives, is naturally conditioned by its objective and, therefore, by the type of technique applied to achieve it. To attain the best results in terms of rock breakage, and with respect to the final profile, it is important to evaluate the specific excavation energy and its optimization. This study, being a revision of different techniques to achieve good quality of the final walls, focuses on evaluating the effects of those techniques on the quality of the result, in both open-pit and underground operations. Different geometries and configurations can be applied to both quarrying and tunneling blasts. This study aims to push contour blasts to their limits, and the main aspects are discussed in order to improve the blast parameters in daily practice.
NLIP and HAD-like Domains of Pah1 and Lipin 1 Phosphatidate Phosphatases Are Essential for Their Catalytic Activities
Authors: Hsu Wei-Hsin , Huang Yi-Hao , Chen Pin-Ru , Hsieh Lu-Sheng
Published: September 2021

Saccharomyces cerevisiae Pah1 phosphatidate phosphatase (PAP) catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, controlling phospholipids and triacylglycerol metabolisms. Pah1 and human Lipin 1 are intrinsically disordered proteins with 56% and 43% unfolded regions, respectively. Truncation analysis of the conserved and non-conserved regions showed that N- and C-conserved regions are essential for the catalytic activity of Pah1. PAP activities can be detected in the conserved N-terminal Lipin (NLIP) domain and C-terminal Lipin (CLIP)/haloacid dehalogenase (HAD)-like domain of Pah1 and Lipin 1, suggesting that the evolutionarily conserved domains are essential for the catalytic activity. The removal of disordered hydrophilic regions drastically reduced the protein solubility of Pah1. Thioredoxin is an efficient fusion protein for production of soluble NLIP–HAD recombinant proteins in Escherichia coli.
Advancing Cave Detection Using Terrain Analysis and Thermal Imagery
Authors: Wynne J. Judson , Jenness Jeff , Sonderegger Derek L. , Titus Timothy N. , Jhabvala Murzy D. , Cabrol Nathalie A.
Published: September 2021

Since the initial experiments nearly 50 years ago, techniques for detecting caves using airborne and spacecraft acquired thermal imagery have improved markedly. These advances are largely due to a combination of higher instrument sensitivity, modern computing systems, and processor-intensive analytical techniques. Through applying these advancements, our goals were to: (1) Determine the efficacy of methods designed for terrain analysis and applied to thermal imagery; (2) evaluate the usefulness of predawn and midday imagery for detecting caves; and (3) ascertain which imagery type (predawn, midday, or the difference between those two times) was most informative. Using forward stepwise logistic (FSL) and Least Absolute Shrinkage and Selection Operator (LASSO) regression analyses for model selection, and a thermal imagery dataset acquired from the Mojave Desert, California, we examined the efficacy of three well-known terrain descriptors (i.e., slope, topographic position index (TPI), and curvature) on thermal imagery for cave detection. We also included the actual, untransformed thermal DN values (hereafter “unenhanced thermal”) as a fourth dataset. Thereafter, we compared the thermal signatures of known cave entrances to all non-cave surface locations. We determined these terrain-based analytical methods, which described the “shape” of the thermal landscape, hold significant promise for cave detection. All imagery types produced similar results. Down-selected covariates per imagery type, based upon the FSL models, were: Predawn— slope, TPI, curvature at 0 m from cave entrance, as well as slope at 1 m from cave entrance; midday— slope, TPI, and unenhanced thermal at 0 m from cave entrance; and difference— TPI and slope at 0 m from cave entrance, as well as unenhanced thermal and TPI at 3.5 m from cave entrance. We provide recommendations for future research directions in terrestrial and planetary cave detection using thermal imagery.
A Comparison of the Different Stages of Dust Events over Beijing in March 2021: The Effects of the Vertical Structure on Near-Surface Particle Concentration
Authors: Wang Futing , Yang Ting , Wang Zifa , Cao Jie , Liu Benli , Liu Jianbao , Chen Shengqian , Liu Shulin , Jia Binghao
Published: September 2021

Mineral dust is of great importance to climate change, air quality, and human health. In this study, multisource data, including the reanalysis data and remote sensing data, were used to compare the three dust events that occurred in the March of 2021 over Beijing and reveal the effects of atmospheric vertical structure on near-surface dust concentration. The combined effect of the Mongolian cyclone and a wide persistent cold-front induced two events (E1: from March 15 to 16 and E3: from March 28 to 29). E1 was more intense, more extensive, and longer-lasting than E3 due to the combination of the stronger Mongolian cyclone, slower high/cold surface pressure, and the low-level jet. However, under the appropriate configurations of temperature and pressure fields between high and low altitudes, weak updrafts were still induced and could elevate dust up to 850 hPa, as occurred during E2 on March 22 and 23. The dust emission was inferior to E1 and E3, which contributes to the low dust concentration near the surface in E2. On the other hand, the downdraft strength directly affected both the vertical distribution of dust and the concentration of surface particles. There was a strong temporal consistency between the occurrence of the downdraft and the dust touchdown. In E1, the continuous strong downdraft caused the maximum dust concentration to be above 4000 μg/m3 at around 200 m. In contrast, the maximum height of the dust mass concentration in E3 occurred at about 800 m due to the transient downdraft, which weakened its effect on surface visibility. Besides, the weak vertical motion in E2 caused most of the dust to become suspended in the air. Overall, the large dust emission resulted from active updrafts in the source region, and the lengthy strong downdrafts led to the ultrahigh particle concentration near the surface.
Remote Sensing-Based Quantification of the Summer Maize Yield Gap Induced by Suboptimum Sowing Dates over North China Plain
Authors: Zhang Sha , Bai Yun , Zhang Jiahua
Published: September 2021

Estimating yield potential (Yp) and quantifying the contribution of suboptimum field managements to the yield gap (Yg) of crops are important for improving crop yield effectively. However, achieving this goal on a regional scale remains difficult because of challenges in collecting field management information. In this study, we retrieved crop management information (i.e., emerging stage information and a surrogate of sowing date (SDT)) from a remote sensing (RS) vegetation index time series. Then, we developed a new approach to quantify maize Yp, total Yg, and the suboptimum SDT-induced Yg (Yg0) using a process-based RS-driven crop yield model for maize (PRYM–Maize), which was developed in our previous study. PRYM–Maize and the newly developed method were used over the North China Plain (NCP) to estimate Ya, Yp, Yg, and Yg0 of summer maize. Results showed that PRYM–Maize outputs reasonable estimates for maize yield over the NCP, with correlations and root mean standard deviation of 0.49 ± 0.24 and 0.88 ± 0.14 t hm−2, respectively, for modeled annual maize yields versus the reference value for each year over the period 2010 to 2015 on a city level. Yp estimated using our new method can reasonably capture the spatial variations in site-level estimates from crop growth models in previous literature. The mean annual regional Yp of 2010–2015 was estimated to be 11.99 t hm−2, and a Yg value of 5.4 t hm−2 was found between Yp and Ya on a regional scale. An estimated 29–42% of regional Yg in each year (2010–2015) was induced by suboptimum SDT. Results also show that not all Yg0 was persistent over time. Future studies using high spatial-resolution RS images to disaggregate Yg0 into persistent and non-persistent components on a small scale are required to increase maize yield over the NCP.
Adapting Semi-Active Prostheses to Real-World Movements: Sensing and Controlling the Dynamic Mean Ankle Moment Arm with a Variable-Stiffness Foot on Ramps and Stairs
Authors: Leestma Jennifer K. , Fehr Katherine Heidi , Adamczyk Peter G.
Published: September 2021

(1) Background: Semi-active prosthetic feet can provide adaptation in different circumstances, enabling greater function with less weight and complexity than fully powered prostheses. However, determining how to control semi-active devices is still a challenge. The dynamic mean ankle moment arm (DMAMA) provides a suitable biomechanical metric, as its simplicity matches that of a semi-active device. However, it is unknown how stiffness and locomotion modes affect DMAMA, which is necessary to create closed-loop controllers for semi-active devices. In this work, we develop a method to use only a prosthesis-embedded load sensor to measure DMAMA and classify locomotion modes, with the goal of achieving mode-dependent, closed-loop control of DMAMA using a variable-stiffness prosthesis. We study how stiffness and ground incline affect the DMAMA, and we establish the feasibility of classifying locomotion modes based exclusively on the load sensor. (2) Methods: Human subjects walked on level ground, ramps, and stairs while wearing a variable-stiffness prosthesis in low-, medium-, and high-stiffness settings. We computed DMAMA from sagittal load sensor data and prosthesis geometric measurements. We used linear mixed-effects models to determine subject-independent and subject-dependent sensitivity of DMAMA to incline and stiffness. We also used a machine learning model to classify locomotion modes using only the load sensor. (3) Results: We found a positive linear sensitivity of DMAMA to stiffness on ramps and level ground. Additionally, we found a positive linear sensitivity of DMAMA to ground slope in the low- and medium-stiffness conditions and a negative interaction effect between slope and stiffness. Considerable variability suggests that applications of DMAMA as a control input should look at the running average over several strides. To examine the efficacy of real-time DMAMA-based control systems, we used a machine learning model to classify locomotion modes using only the load sensor. The classifier achieved over 95% accuracy. (4) Conclusions: Based on these findings, DMAMA has potential for use as a closed-loop control input to adapt semi-active prostheses to different locomotion modes.
Acoustic Emission-Based Condition Monitoring and Remaining Useful Life Prediction of Hydraulic Cylinder Rod Seals
Authors: Pedersen Jørgen F. , Schlanbusch Rune , Meyer Thomas J. J. , Caspers Leo W. , Shanbhag Vignesh V.
Published: September 2021

The foremost reason for unscheduled maintenance of hydraulic cylinders in industry is caused by wear of the hydraulic seals. Therefore, condition monitoring and subsequent estimation of remaining useful life (RUL) methods are highly sought after by the maintenance professionals. This study aimed at investigating the use of acoustic emission (AE) sensors to identify the early stages of external leakage initiation in hydraulic cylinders through run to failure studies (RTF) in a test rig. In this study, the impact of sensor location and rod speeds on the AE signal were investigated using both time- and frequency-based features. Furthermore, a frequency domain analysis was conducted to investigate the power spectral density (PSD) of the AE signal. An accelerated leakage initiation process was performed by creating longitudinal scratches on the piston rod. In addition, the effect on the AE signal from pausing the test rig for a prolonged duration during the RTF tests was investigated. From the extracted features of the AE signal, the root mean square (RMS) feature was observed to be a potent condition indicator (CI) to understand the leakage initiation. In this study, the AE signal showed a large drop in the RMS value caused by the pause in the RTF test operations. However, the RMS value at leakage initiation is seen to be a promising CI because it appears to be linearly scalable to operational conditions such as pressure and speed, with good accuracy, for predicting the leakage threshold.