bluuebunny/crossref_metadata_2025 huggingface dataset:
Three New Species, Two New Records and Four New Collections of Tubeufiaceae from Thailand and China
Authors: Tian Xingguo , Karunarathna Samantha C. , Xu Rongju , Lu Yongzhong , Suwannarach Nakarin , Mapook Ausana , Bao Danfeng , Xu Jianchu , Tibpromma Saowaluck
Published: February 2022

Tubeufiaceae, a cosmopolitan family with a worldwide distribution, is mostly reported as saprobic on decaying woody materials from both aquatic and terrestrial habitats. The family is commonly found as helicosporous hyphomycetes, while some are chlamydosporous and phragmosporous. In this study, thirteen helicosporous hyphomycetes were collected from Thailand and China. The phylogenetic analyses of combined ITS, LSU, TEF1-α, and RPB2 sequence data placed them in Dematiohelicomyces, Helicoma, Helicotruncatum, Neohelicosporium, Parahelicomyces, and Tubeufia within Tubeufiaceae. Three new species, Tubeufia cocois, Parahelicomyces chiangmaiensis, and Neohelicosporium bambusicola, one new host record, Tubeufia laxispora, and one new geographic record, T. longihelicospora, are introduced based on both morphological characteristics and phylogenetic analyses. In addition, Dematiohelicomyces helicosporus, Helicoma guttulatum, Helicotruncatum palmigenum, and Tubeufia cylindrothecia are described with detailed descriptions and color photo plates.
Pharmacogenomics and Pediatric Asthmatic Medications
Authors: Lim Christy , Priefer Ronny
Published: February 2022

Asthma is a respiratory condition often stemming from childhood, characterized by difficulty breathing and/or chest tightness. Current treatment options for both adults and children include beta-2 agonists, inhaled corticosteroids (ICS), and leukotriene modifiers (LTM). Despite recommendations by the Global Initiative for Asthma, a substantial number of patients are unresponsive to treatment and unable to control symptoms. Pharmacogenomics have increasingly become the front line of precision medicine, especially with the recent use of candidate gene and genome- wide association studies (GWAS). Screening patients preemptively could likely decrease adverse events and therapeutic failure. However, research in asthma, specifically in pediatrics, has been low. Although numerous adult trials have evaluated the impact of pharmacogenomics and treatment response, the lack of evidence in children has hindered progress towards clinical application. This review aims to discuss the impact of genetic variability and response to asthmatic medications in the pediatric population.
The Role of Robotic Visceral Surgery in Patients with Adhesions: A Systematic Review and Meta-Analysis
Authors: Milone Marco , Manigrasso Michele , Anoldo Pietro , D’Amore Anna , Elmore Ugo , Giglio Mariano Cesare , Rompianesi Gianluca , Vertaldi Sara , Troisi Roberto Ivan , Francis Nader K. , De Palma Giovanni Domenico
Published: February 2022

Abdominal adhesions are a risk factor for conversion to open surgery. An advantage of robotic surgery is the lower rate of unplanned conversions. A systematic review was conducted using the terms “laparoscopic” and “robotic”. Inclusion criteria were: comparative studies evaluating patients undergoing laparoscopic and robotic surgery; reporting data on conversion to open surgery for each group due to adhesions and studies including at least five patients in each group. The main outcomes were the conversion rates due to adhesions and surgeons’ expertise (novice vs. expert). The meta-analysis included 70 studies from different surgical specialities with 14,329 procedures (6472 robotic and 7857 laparoscopic). The robotic approach was associated with a reduced risk of conversion (OR 1.53, 95% CI 1.12–2.10, p = 0.007). The analysis of the procedures performed by “expert surgeons” showed a statistically significant difference in favour of robotic surgery (OR 1.48, 95% CI 1.03–2.12, p = 0.03). A reduced conversion rate due to adhesions with the robotic approach was observed in patients undergoing colorectal cancer surgery (OR 2.62, 95% CI 1.20–5.72, p = 0.02). The robotic approach could be a valid option in patients with abdominal adhesions, especially in the subgroup of those undergoing colorectal cancer resection performed by expert surgeons.
Comparison of Long-Term Pneumonia Risk between Spleen Injury and Non-Spleen Injury after Total Splenectomy—A Population-Based Study
Authors: Lin Chun-Cheng , Hsu Sheng-Der , Chien Wu-Chien , Chung Chi-Hsiang , Chen Cheng-Jueng , Liang Chia-Ming , Hong Zhi-Jie
Published: February 2022

Patients who undergo splenectomy are at a high risk of infection. We aimed to investigate the rate of pneumonia in patients who underwent splenectomy, specifically comparing those who had splenectomy due to spleen injury and those who had it for other reasons. A population-based cohort study was conducted. Overall, 17,498 patients who underwent splenectomy between 2000 and 2015 were enrolled, including 11,817 patients with a history of spleen injury and 5681 controls without spleen injury. The incidence of pneumonia was calculated at the end of 2016. A multivariable Cox proportional hazards regression model was used to compare the hazard ratio with 95% CI for pneumonia associated with the spleen injury-caused splenectomy and splenectomy due to other causes. The crude HR for patients with splenectomy due to spleen injury to develop pneumonia was 1.649. After adjusting for covariates, the adjusted hazard ratio was 1.567. There were statistically significant differences in all subgroups, except for the group with a tracking duration >10 years. We found an increase in pneumonia risk in the ‘spleen injury’ group when comparing it to that of the ‘other causes’ group, regardless of age, sex, and area of residence.
The Role of Radiation in Cancer Treatment: New Insights towards Personalized Therapies
Authors: Minafra Luigi , Cammarata Francesco P. , Calvaruso Marco
Published: February 2022

Despite all the recent pharmacological advances and the introduction of targeted therapies in clinical practice, cancer still remains one of the leading cause of death, accounting for 10 million deaths per year, based on the most recent reports [...]
Automatic Microaneurysms Detection for Early Diagnosis of Diabetic Retinopathy Using Improved Discrete Particle Swarm Optimization
Authors: Bhimavarapu Usharani , Battineni Gopi
Published: February 2022

Diabetic retinopathy (DR) is one of the most important microvascular complications associated with diabetes mellitus. The early signs of DR are microaneurysms, which can lead to complete vision loss. The detection of DR at an early stage can help to avoid non-reversible blindness. To do this, we incorporated fuzzy logic techniques into digital image processing to conduct effective detection. The digital fundus images were segmented using particle swarm optimization to identify microaneurysms. The particle swarm optimization clustering combined the membership functions by grouping the high similarity data into clusters. Model testing was conducted on the publicly available dataset called DIARETDB0, and image segmentation was done by probability-based (PBPSO) clustering algorithms. Different fuzzy models were applied and the outcomes were compared with our probability discrete particle swarm optimization algorithm. The results revealed that the proposed PSO algorithm achieved an accuracy of 99.9% in the early detection of DR.
Statistical Analysis Dow Jones Stock Index—Cumulative Return Gap and Finite Difference Method
Authors: Yan Kejia , Gupta Rakesh , Haddad Sama
Published: February 2022

This study was motivated by the poor performance of the current models used in stock return forecasting and aimed to improve the accuracy of the existing models in forecasting future stock returns. The current literature largely assumes that the residual term used in the existing model is white noise and, as such, has no valuable information. We exploit the valuable information contained in the residuals of the models in the context of cumulative return and construct a new cumulative return gap (CRG) model to overcome the weaknesses of the traditional cumulative abnormal returns (CAR) and buy-and-hold abnormal returns (BHAR) models. To deal with the residual items of the prediction model and improving the prediction accuracy, we also lead the finite difference (FD) method into the autoregressive (AR) model and autoregressive distributed lag (ARDL) model. The empirical results of the study show that the cumulative return (CR) model is better than the simple return model for stock return prediction. We found that the CRG model can improve prediction accuracy, the term of the residuals from the autoregressive analysis is very important in stock return prediction, and the FD model can improve prediction accuracy.
The Perception of the Vertical Dimension (3D) through the Lens of Different Stakeholders in the Property Market of China
Authors: Ying Yue , Koeva Mila , Kuffer Monika , Asiama Kwabena Obeng , Li Xia , Zevenbergen Jaap
Published: February 2022

China has experienced fast urbanization with a growing urban population, which has inevitably led to the adoption of a vertical housing style with high-rise buildings. However, how people subjectively perceive the vertical dimension (3D) in the property market is neither adequately documented nor well understood. The 3D perception helps us to understand a myriad of social and psychological effects of living in high-rise buildings. We organized and conducted semi-structured expert interviews, focus groups, and the circulation and compilation of questionnaires in Xi’an, China, to investigate how different stakeholders in the property market perceive 3D. The results show that: (1) real estate developers do not adjust property prices for specific 3D factors, and the local government does not consider 3D in housing policies; (2) the current status of 3D modeling in Xi’an is still in the embryonic state; (3) 3D factors are highly valued by buyers but not well-understood by real estate developers and local government. In addition, 3D factors score higher than horizontal (2D) factors (1.12 to 0.88). Gender and age groups do not influence housing preferences concerning 2D and 3D factors. These findings provide valuable insights for real estate developers concerning pricing policies and the local government concerning housing policies. In the future, 3D perceptions and factors should be prioritized in order to improve urban infrastructure and ensure the increased availability of, and fair public access to welfare related to 3D in urban areas.
Extracting Land Use Change Patterns of Rural Town Settlements with Sequence Alignment Method
Authors: Xie Senkai , Zhang Wenjia , Zhao Yi , Tong De
Published: February 2022

Understanding land use change patterns of rural town settlements (RTSs) is crucial for rural and small-town planning; however, few studies have explored pattern mining approaches to RTS trajectory analysis. In this study, we adopted a novel method by building sequence alignment method (SAM) to detect representative trajectory clusters of land use change of 1158 RTSs in seven waves from 1980 to 2015 in Guangdong, China. The results suggest that there are 10 clusters of RTSs with varying trajectories of land use change, implying their differences in the development processes and underlying socioeconomic, demographical, and institutional factors. A spatial distribution map of RTSs shows that stable cultivated ecological and stable ecologically dominant RTSs are distributed in the northern, eastern, and western parts of Guangdong, whereas stable rural construction and stable mixed construction RTSs are mostly located around the provincial boundary. Notably, 73% of the RTSs that have undergone changes in land use types are located in the Pearl River Delta (PRD), including urbanized and agricultural upgraded RTSs. The analysis presented here summarizes the driving forces of the spatial evolution of RTSs, including the location, landforms, industries, and policy factors. This study provides dynamic policy implications to understand longitudinal and sequential spatial restructuring and regional coordinated development in the fast-growing PRD area.
The Application of the Environment Act 2021 Principles to Carbon Capture and Storage
Authors: Rutherford Angelica
Published: February 2022

Carbon Capture and Storage (CCS) is a new technology considered to have the potential to decarbonise economies. However, nationally and internationally the use of CCS has also been raising concerns about its potential global risks and adverse impacts on the environment. CCS was part of the discussions at the fourth United Nations Environment Assembly (UNEA) in March 2019 and in side-events in the 26th UN Climate Change Conference that took place in Glasgow in November 2021. The UK Government aims to deploy CCS at scale during the 2030s, subject to cost reduction. At the same time, the UK Government has recently enacted the Environment Act 2021, which provides a set of five environmental principles: the integration principle, the principle of preventative action, the precautionary principle, the rectification at source principle and the polluter pays principle. This work seeks to analyse the application of the UK environmental law principles to carbon capture and storage policies in the United Kingdom and its balance with other considerations. Given the concerns surrounding the use of CCS, the debate about its legality may arise in the United Kingdom and in other countries. To this end, this paper initially carries out a systematic review of CCS policy documents to discover the policy considerations that support the development of CCS. It then examines the application of the UK environmental law principles to CCS initiatives and its balance with other considerations, such as reduction of carbon emissions, security of energy supply, economic growth and technological leadership. In doing so, this paper aims at contributing to the debate surrounding recent technological developments that have been utilised to help address climate change and some of the legal challenges emerging through the use of CCS under UK environmental law.
Vitamin E: Where Are We Now in Vascular Diseases?
Authors: Garg Anahita , Lee Jetty Chung-Yung
Published: February 2022

Vitamin E is one of the most popular fat-soluble vitamins in pathological research and has been under scrutiny since the 1980s as a vital dietary component of food. The antioxidant effect of vitamin E has been widely studied due to its benefits in the prevention of various cardiovascular diseases. In recent years, alternative effects of vitamin E, in terms of anti-inflammatory pathways and gene regulation, have also been of interest to researchers. This review examines the role of dietary vitamin E (α-tocopherol) as an antioxidant and bioactive molecule in promoting vascular health. While the antioxidant effect of vitamin E is well established, knowledge about its capacity as a promising regulatory molecule in the control of the vascular system is limited. The aim of this review is to discuss some of these mechanisms and summarize their role in the prevention of cardiovascular diseases (CVD). Here, we also briefly discuss foods rich in vitamin E, and deliberate some potential toxicological effects of excessive supplemental vitamin E in the body.
Design of an Articulated Neck to Assess Impact Head-Neck Injuries
Authors: Rueda-Arreguín José Luis , Ceccarelli Marco , Torres-SanMiguel Christopher René
Published: February 2022

This paper describes a new solution for an articulated low-cost artificial neck with sensors to assess the effects of head impacts. This prototype is designed as a new solution to evaluate the neck’s response after suffering the head impact. An overview of existing solutions is reported to evaluate the advantages and disadvantages of each one briefly. Problems and requirements for prototype design are outlined to guide to a solution with commercial components. A prototype is developed, and its operating performance is evaluated through a lab test. Several tests are worked out considering the biomechanics involved in the most common accidents of head-neck impacts. Results show a response on the prototype similar to an actual human neck. Future improvements are also outlined for better accurate responses considering the results from the lab test.
Ghassan Chebaro’s 2022 and the Forgotten Climate Crisis in the Middle East. Book Review: Chebaro (2009). 2022. Beirut: Arab Scientific Publishers. ISBN: 978-9953875118
Authors: Ghashmari Ahmad A.
Published: February 2022

The article discusses Ghassan Chebaro’s novel 2022 and the importance of grassroots action in battling the impending climate disaster in the Middle East. The article contrasts the novel’s optimism with the disappointing reality of inaction that is exacerbating the climate crisis. It also addresses the interconnectedness of capitalism, the military industrial complex, and the climate crisis.
Micro-to-Nanometer Scale Patterning of Perovskite Inks via Controlled Self-Assemblies
Authors: Kang Misun , Choi Dooho , Bae Jae Young , Byun Myunghwan
Published: February 2022

In the past decade, perovskite materials have gained intensive interest due to their remarkable material properties in optoelectronics and photodetectors. This review highlights recent advances in micro-to-nanometer scale patterning of perovskite inks, placing an undue emphasis on recently developed approaches to harness spatially ordered and crystallographically oriented structures with unprecedented regularity via controlled self-assemblies, including blade coating, inkjet printing, and nanoimprinting. Patterning of the perovskite elements at the micro- or nanometer scale might be a key parameter for their integration in a real system. Nowadays, unconventional approaches based on irreversible solution evaporation hold an important position in the structuring and integration of perovskite materials. Herein, easier type patterning techniques based on evaporations of polymer solutions and the coffee ring effect are systematically reviewed. The recent progress in the potential applications of the patterned perovskite inks is also introduced.
Significant Near-Field Enhancement over Large Volumes around Metal Nanorods via Strong Coupling of Surface Lattice Resonances and Fabry–Pérot Resonance
Authors: Shi Yunjie , Dong Yuming , Sun Degui , Li Guangyuan
Published: February 2022

Metal nanoparticles supporting plasmons are widely used to enhance electromagnetic fields, resulting in strong light–matter interactions at the nanoscale in a diverse range of applications. Recently, it has been shown that when metal nanorods are periodically arranged with proper lattice periods, surface lattice resonances (SLRs) can be excited and near fields can be greatly enhanced over extended volumes. In this work, we report significant near field enhancement over even larger volumes by placing the metal nanorod array within a Fabry–Pérot (F-P) microcavity. Simulation results show that by taking advantage of strong coupling between the SLR and the photonic F-P resonances, the electric field intensity of the bonding split mode can be enhanced by up to 1935 times, which is about three times of the enhancement of the SLR, and the greatly enhanced field can extend over most of the F-P microcavity. We further show that the F-P resonances of both odd and even orders can strongly couple to the SLR by varying the nanorods position from the middle of the microcavity. We expect that the proposed plasmonic-photonic coupling system will find promising applications in nanolasers, nonlinear optics and sensing.
Characterization and Comparison of Corrosion Layer Microstructure between Cement Mortar and Alkali-Activated Fly Ash/Slag Mortar Exposed to Sulfuric Acid and Acetic Acid
Authors: Zhao Wenjing , Fan Zirui , Li Xin , Kong Lijuan , Zhang Liying
Published: February 2022

In this study, we investigated the formation and evolution of the corrosion layers in alkali-activated mortar and ordinary Portland cement mortar exposed to sulfuric acid and acetic acid environments with different pH values, and explored the differences in the deterioration mechanisms. The experimental results indicated that ordinary Portland cement (OPC) mortars experienced more severe deterioration in terms of appearance, mass loss, and strength loss as compared with alkali-activated mortars exposed to an acetic acid environment, but their neutralization depths were smaller. Alkali-activated fly ash (AAF) mortar had a the relatively intact appearance but the greatest neutralization depth, which was due to its stable three-dimensional network but highly porous structure. To sum up, alkali-activated fly ash/slag (AFS) mortar had the best resistance to acid attack. In addition, the mortars exposed to acetic acid suffered greater deterioration than those exposed to sulfuric acid with the same pH values, which was mainly due to the highly porous corrosion layer formed in acetic acid, whereas crystallization of gypsum in sulfuric acid had a pore filling effect. However, for alkali-activated slag (AAS) and OPC mortars exposed to a sulfuric acid environment, extensive gypsum resulted in the formation of micro-cracks, and the corrosion layer of OPC mortar was more prone to fall off. OPC mortar also had the greatest resistance difference values of the continuously connected micro-pores before and after acid corrosion, followed by AAS, AAF, and AFS mortars, and these values for all the specimens were smaller in sulfuric acid. Furthermore, the gaps between acetic and sulfuric acid attacks increased with increased calcium content in binders, which were 7%, 13%, 21%, and 29% for AAF, AFS, AAS, and OPC mortars, respectively. Thus, it can be inferred that an appropriate amount of gypsum existed in the corrosion layer which could act as a barrier to some extent ina sulfuric acid environment.
Vibration Serviceability of Footbridges Made of the Sustainable and Eco Structural Material: Glued-Laminated Wood
Authors: Hawryszków Paweł , Biliszczuk Jan
Published: February 2022

In this paper, dynamic analyses of two untypical, modern footbridges made of glued-laminated timber are presented. One of them is among the longest cable-stayed bridges for pedestrians in the world, made of such a structural material. Both structures are qualified as having low sensitivity to vibrations. The results of numerical modal analysis using FEM and non-destructive experimental dynamic tests of investigated footbridges are compared. Important differences in obtained results are captured, which are identified as the positive effect in relation to design aspects. Moreover, the same in situ measurements confirm the high level of damping in footbridges made of glued-laminated wood, which is a very significant and distinguishing feature not commonly recognized. The study also calls attention to the choice of timber as an advisable material for footbridges. This is not only because of environmentally friendly and aesthetic reasons, but also due to providing highly satisfying vibration comfort for pedestrians.
Sustainable Alkaline Hydrolysis of Polyester Fabric at Low Temperature
Authors: Čorak Ivana , Tarbuk Anita , Đorđević Dragan , Višić Ksenija , Botteri Lea
Published: February 2022

High crystallinity leads to low hydrophilicity of fabric made of (poly(ethylene terephthalate)) fibers (PET) causing problems in finishing, washing, and dyeing processes. To improve these properties, the surface of PET fibers is usually modified by hydrolysis. Alkaline hydrolysis is a conventional process usually performed at a temperature higher than 100 °C for more than 1 h. However, the use of strong alkali and high processing temperatures (>100 °C) can lead to fabric damage and a negative impact on the environment. Therefore, in this paper, the possibility of hydrolysis of the PET fibers in the fabric in a sustainable, energy-efficient process was researched. The influence of low temperature (60–100 °C) and an accelerator (a cationic surfactant HDTMAC) to PET alkaline hydrolysis was studied through weight loss, the loss in breaking force, and fiber morphology. The kinetics of PET dissolution in 1.5 mol cm−3 NaOH at low temperature with and without the addition of HDTMAC was determined and the activation energy was calculated according to the theoretical model. It has been confirmed that PET hydrolysis can be carried out in 1.5 mol cm−3 NaOH with the addition of HDTMAC as an accelerator at 80 °C for 10 min. This process is more economically and energetically acceptable than the conventional process, and is therefore more sustainable.
Milling Al520-MMC Reinforced with SiC Particles and Additive Elements Bi and Sn
Authors: Alipour Sougavabar Mahmoud , Niknam Seyed Ali , Davoodi Behnam , Songmene Victor
Published: February 2022

In recent years and due to advanced fabrication techniques of composites, many of these functional materials have been brought to the forefront with more benefits. Amongst composites, special attention has been paid to metal matrix composites (MMCs). Reinforced aluminum MMCs with nanoparticles are among the new MMCs with a wide range of industry applications. The combination of aluminum as a soft, lightweight, and low-strength material with silicon carbide (SiC), bismuth (Bi), and tin (Sn) particles, which are hard and high-strength materials, may lead to the generation of high-strength and lightweight material, which can be classified as difficult to cut material. According to literature, limited studies have been reported on the effects of various reinforcing elements on the machinability of Al-MMC, in principle tool wear morphology and size and surface quality. According to statistical analysis, the effect of cutting parameters and reinforcing particles on the surface quality attributes is not statistically significant. In contrast, the effect of cutting parameters and reinforcing particles on the tool flank wear is significant and reliable. In addition, it is observed that the reinforcing particles and cutting speed have the most significant effects, and the lubrication mode has a minor impact on the tool flank wear.
Analytical Methods for Causality Evaluation of Photonic Materials
Authors: Stefański Tomasz P. , Gulgowski Jacek , Tsakmakidis Kosmas L.
Published: February 2022

We comprehensively review several general methods and analytical tools used for causality evaluation of photonic materials. Our objective is to call to mind and then formulate, on a mathematically rigorous basis, a set of theorems which can answer the question whether a considered material model is causal or not. For this purpose, a set of various distributional theorems presented in literature is collected as the distributional version of the Titchmarsh theorem, allowing for evaluation of causality in complicated electromagnetic systems. Furthermore, we correct the existing material models with the use of distribution theory in order to obtain their causal formulations. In addition to the well-known Kramers–Krönig (K–K) relations, we overview four further methods which can be used to assess causality of given dispersion relations, when calculations of integrals involved in the K–K relations are challenging or even impossible. Depending on the given problem, optimal approaches allowing us to prove either the causality or lack thereof are pointed out. These methodologies should be useful for scientists and engineers analyzing causality problems in electrodynamics and optics, particularly with regard to photonic materials, when the involved mathematical distributions have to be invoked.
Hydrothermal Separation of Titanium Vanadium and Chromium from a Pregnant Oxalic Acid Leachate
Authors: Dong Zihui , Zhang Jie , Yan Baijun
Published: February 2022

The separation of titanium, vanadium and chromium in vanadium slag (VS) is a difficult problem restricting the comprehensive utilization of VS. This paper presents the first study on the separation of titanium, vanadium and chromium from oxalic acid leachate of VS. Firstly, the separation of titanium from the leachate by hydrothermal method was studied. The results show that more than 99% of titanium in the leachate was precipitated in the form of spherical anatase TiO2 with the purity of 95.7%. Then, the extraction separation of vanadium and chromium from the titanium-free filtrate by three-stage extraction of acidified N235 extractant and four-stage stripping of HCl solution was investigated. The extraction mechanism was identified as the anion exchange reaction between acidified N235 extractant and vanadium and chromium complex anions, which were further stripped by HCl solution in the stripping process. After obtaining the concentrated and purified stripping solution containing vanadium and chromium, the separation of vanadium and chromium from the stripping solution by hydrothermal method was studied, and the product was mainly composed of VO2 and Cr2O3. This process provides an idea for the comprehensive utilization of titanium, vanadium and chromium in oxalic acid system.
Porosity of a Fast-Setting Mortar with Crystallization Admixture and Effect of a SA-PA Modification
Authors: Cotini Oscar , Di Maggio Rosa , Tonelli Daniel , Nascimben Roger , Ataollahi Narges
Published: February 2022

Air permeability measurements according to the Hagen–Poiseuille equation, Scanning Electron Microscopy (SEM) and mercury intrusion porosimetry (MIP) tests were conducted on samples of cementitious mortar at different curing times to study the correlation between the increased crystallization and their microstructure. The mortar samples were prepared with a commercial fast-setting premix containing calcium silicates and quartz. The average permeability coefficient (K) was 2.96 × 10−15 m2 after 3 days and decreased to 3.07 × 10−17 m2 after about one month. The continuous C-S-H nucleation in the capillary pores of the cement mortar changes their shape and improves the mortar’s impermeability. The SEM images showed the development of crystals that refine the pore size distribution of the cement paste, with more of the smallest pores, and fewer of the largest, as demonstrated by the MIP measurements. Adding a superabsorbent polyacrylate (SA-PA) in the amount of 0.5% wt of dry powder, without adding any extra water, makes a mortar less fluid but not faster-setting. Twenty-four hours after mixing and casting, it is still plastic and, with time, the pore size distribution differs from that of standard mortar. Over time in air, permeability remains high, but in water it could be low due to swelling of SA-PA residues.
Interfacial Polarization Phenomena in Compressed Nanowires of SbSI
Authors: Starczewska Anna , Mistewicz Krystian , Kozioł Mateusz , Zubko Maciej , Stróż Danuta , Dec Jan
Published: February 2022

The systematic studies of the extrinsic Maxwell–Wagner–Sillars polarization process in compressed antimony sulfoiodide (SbSI) nanowires are carried out by dielectric spectroscopy. The dielectric response is studied in temperature (100≤T≤350) K and frequency (10−3≤f≤106) Hz ranges. Dielectric functions commonly used for the analysis of dielectric spectra related to intrinsic polarization processes were applied in the elaboration of experimental data. It was found that the respective “semi-circles” in the Cole–Cole-type plots display a characteristic pear-like shape for the ferroelectric phase. On the other hand, the data for the paraelectric phase form symmetrical arcs. This response is effectively parametrized using the experimental Cole–Davidson and Cole–Cole functions fitted to the data obtained for the ferroelectric and paraelectric phases, respectively. It is deduced that the particular shape of spectra in the ferroelectric phase is due to spontaneous polarization, which is responsible for an asymmetric broadening of relaxation functions related to the interfacial polarization.
Influence of Cement Replacement with Sewage Sludge Ash (SSA) on the Heat of Hydration of Cement Mortar
Authors: Haustein Elżbieta , Kuryłowicz-Cudowska Aleksandra , Łuczkiewicz Aneta , Fudala-Książek Sylwia , Cieślik Bartłomiej Michał
Published: February 2022

The amount of fly ash from the incineration of sewage sludge is increasing all over the world, and its utilization is becoming a serious environmental problem. In the study, a type of sewage sludge ash (SSA) collected directly from the municipal sewage treatment plant was used. Five levels of cement replacement (2.5%, 5%, 7.5%, 10% and 20%) and unchanged water-to-binder (w/b) ratio (0.55) were used. The purpose of the study was to evaluate the effect of sewage sludge ash (SSA) on the hydration heat process of cement mortars. The heat of the hydration of cement mortars was monitored by the isothermal calorimetric method for 7 days at 23 °C. The analysis of chemical composition and particle size distribution was performed on the tested material. The tests carried out have shown that SSA particles have irregular grain morphology and, taking into account the chemical composition consists mainly of oxides such as CaO, P2O5, SiO2 and Al2O3. The concentration of these compounds affects the hydration process of cement mortars doped with SSA. In turn, the content of selected heavy metals in the tested ash should not pose a threat to the environment. Calorimetric studies proved that the hydration process is influenced by the presence of SSA in cement mortars. The studies showed that the rate of heat generation decreased (especially in the initial setting period) with the increasing replacement of cement by SSA, which also reduced the amount of total heat compared to the control cement mortar. With increasing mass of the replacement of cement with SSA up to 20%, the 7-day compressive strength of the mortar samples decreases.
Effect of Radiofrequency Plasma Spheroidization Treatment on the Laser Directed Energy Deposited Properties of Low-Cost Hydrogenated-Dehydrogenated Titanium Powder
Authors: Liu Min , Huang Liufei , Ren Congcong , Wang Dou , Li Qiang , Li Jinfeng
Published: February 2022

Titanium for additive manufacturing presents a challenge in the control of costs in the fabrication of products with expanding applications compared with cast titanium. In this study, hydrogenated–dehydrogenated (HDH) titanium powder with a low cost was employed to produce spherical Ti powder using the radiofrequency plasma (RF) technique. The spherical Ti powder was used as the raw material for laser directed energy deposition (LDED) to produce commercially pure titanium (CP-Ti). Microstructural analyses of the powder revealed that RF treatment, not only optimized the shape of the titanium powder, but also benefited in the removal of the residual hydride phase of the powder. Furthermore, the LDED-HDH-RF-produced samples showed an excellent combination of tensile strength and tensile ductility compared to the cast and the LDED-HDH-produced samples. Such an enhancement in the mechanical properties was attributed to the refinement of the α grain size and the dense microstructure. The present work provides an approach for LDED-produced CP-Ti to address the economic and mechanical properties of the materials, while also providing insights into the expanding application of HDH titanium powder.
Effect of Different Types of “Dry Way” Additions in Porous Asphalt Mixtures
Authors: Lastra-González Pedro , Rodriguez-Hernandez Jorge , Real-Gutiérrez Carlos , Castro-Fresno Daniel , Vega-Zamanillo Ángel
Published: February 2022

Polymers are widely used to improve the mechanical performance of asphalt mixtures. Among them, styrene butadiene styrene (SBS) is the most commonly used, especially in the wet modification of virgin bitumen. This method, which is extensively utilized, has several advantages, but also some disadvantages, concerning its performance (such as the risk of instability or a lack of homogeneity) and logistical management (such as the need for special equipment, the transport of materials, and the dependence on the refinery that modifies the bitumen). This paper analyses the use of the most conventional types of polymers (two types of SBS, one type of BS, and rubber from end-of-life tires), dry added, as an alternative method. They have been used in porous asphalt mixtures. This type of bituminous mixture is usually designed with commercial polymer-modified bitumen, due to the mechanical requirements, and it is very sensitive to the properties of the binder used. The mechanical behavior of experimental porous asphalt mixtures has been significantly improved, especially in the case of SBS, although the performance did not reach that of commercial polymer-modified bitumen. The results have shown that the dry method is a suitable and feasible option to manufacture modified mixtures, especially considering its advantages, from a logistical viewpoint, in comparison with the wet method.
Effect of Equal Volume Replacement of Fine Aggregate with Fly Ash on Carbonation Resistance of Concrete
Authors: Zhang Dongsheng , Wang Yafan , Ma Mingxiao , Guo Xiangjun , Zhao Shuangquan , Zhang Shuxiang , Yang Qiuning
Published: February 2022

Concrete is prepared by substituting an equal volume of fly ash for fine aggregate, and the effect of substitution rate on its carbonation resistance is studied. Using a rapid carbonation test, the distribution law of the internal pH value of concrete with fly ash as fine aggregate (CFA) along the carbonation depth under different substitution rates (10%, 20%, 30%, and 40%) after carbonation is studied and compared with the test results of phenolphthalein solution. Then, to further clarify the damage mechanism of fly ash replacing fine aggregate on concrete carbonation, the changes in the pore structure and micromorphology of CFA after carbonation are studied by means of mercury intrusion pressure and electron microscope scanning tests. The results indicate that the carbonation depth of CFA increases gradually with increasing carbonation time. In particular, in the later stage of carbonation, the carbonation rate of concrete decreases significantly with an increase in the substitution rate. The carbonation depth XC of CFA measured by phenolphthalein solution is approximately 0.24–0.39 times of the complete noncarbonation depth measured by the pH method. The pH value test is a reliable test method that can reveal the carbonation mechanism of CFA. Carbonation can significantly reduce the proportion of more harmful holes in concrete with a large amount of fly ash, but it can also increase the proportion of less harmful and harmful holes. In general, the pore size distribution and micromorphology of concrete can be improved by replacing fine aggregates with fly ash.
Effect of the Biodegradable Component Addition to the Molding Sand on the Microstructure and Properties of Ductile Iron Castings
Authors: Major-Gabryś Katarzyna , Hosadyna-Kondracka Małgorzata , Polkowska Adelajda , Warmuzek Małgorzata
Published: February 2022

In this work, the results of the examinations of the effect of the mold material and mold technology on the microstructure and properties of the casts parts of ductile cast iron have been presented. Four different self-hardening molding sands based on fresh silica sand from Grudzen Las, with organic binders (no-bake process), were used to prepare molds for tested castings. A novelty is the use of molding sand with a two-component binder: furfuryl resin-polycaprolactone PCL biomaterial. The molds were poured with ductile iron according to standard PN-EN 1563:2018-10. The microstructure of the experimental castings was examined on metallographic cross-sections with PN-EN ISO 945-1:2019-09 standard. Observations were made in the area at the casting/mold boundary and in a zone approximately 10 mm from the surface of the casting with a light microscope. The tensile test at room temperature was conducted according to standard PN-EN ISO 6892-1:2016-09. Circular cross-section test pieces, machined from samples taken from castings, were used. In the present experiment, it was stated that interactions between the mold material of different compositions and liquid cast iron at the stage of casting solidification led to some evolution of casting’s microstructure in the superficial layer, such as a pearlite rim observed for acidic mold sand, a ferritic rim for alkaline sand, and graphite spheroids degeneration, especially spectacular for the acidic mold with polycaprolactone (PCL) addition. These microstructural effects may point to the interference of the direct chemical interactions between liquid alloy and the components released from the mold sand, such as sulfur and oxygen. Particularly noteworthy is the observation that the use of molding sand with furfuryl resin with the addition of biodegradable PCL material does not lead to an unfavorable modification of the mechanical properties in the casting. The samples taken from Casting No. 2, made on the acidic molding sand with the participation of biodegradable material, had an average strength of 672 MPa, the highest average strength UTS-among all tested molding sands. However, the elongation after fracture was 48% lower compared to the reference samples from Casting No. 1 from the sand without the addition of PCL.
Surface Cleaning Effect of Bare Aluminum Micro-Sized Powder by Low Oxygen Induction Thermal Plasma
Authors: Kim Dasom , Hirayama Yusuke , Takagi Kenta , Kwon Hansang
Published: February 2022

The development of bare metal powder is desirable for obtaining conductive interfaces by low-temperature sintering to be applied in various industries of 3D printing, conductive ink or paste. In our previous study, bulk Al made from Al nanopowder that was prepared with low-oxygen thermal plasma (LO-ITP), which is the original metal powder production technique, showed high electrical conductivity comparable to Al casting material. This study discusses the surface cleaning effect of Al particles expected to be obtained by peeling the surface of Al particles using the LO-ITP method. Bare metal micro-sized powders were prepared using LO-ITP by controlling the power supply rate and preferentially vaporizing the oxidized surface of the Al powder. Electrical conductivity was evaluated to confirm if there was an oxide layer at the Al/Al interface. The Al compact at room temperature produced from LO-ITP-processed Al powder showed an electrical conductivity of 2.9 · 107 S/m, which is comparable to that of cast Al bulk. According to the microstructure observation, especially for the interfaces between bare Al powder, direct contact was achieved at 450 °C sintering. This process temperature is lower than the conventional sintering temperature (550 °C) of commercial Al powder without any surface cleaning. Therefore, surface cleaning using LO-ITP is the key to opening a new gate to the powder metallurgy process.
Experimental Investigation on the Effect of Dry Ice Compression on the Poisson Ratio
Authors: Biszczanik Aleksandra , Górecki Jan , Kukla Mateusz , Wałęsa Krzysztof , Wojtkowiak Dominik
Published: February 2022

In the processing of waste materials, attention must be given to the efficient use of energy. The pelletization of dry ice is a good example of such processes. A literature review shows that in the pelletizers available on the market, the force applied in the process is excessive. As a result, the efficiency of the utilization of inputs, including electricity and carbon dioxide, is at a very low level. This article presents the results of experimental research on the effect of the degree of dry ice compression on the value of the Poisson ratio. The first part of this article presents the research methodology and a description of the test stand, developed specifically for this research, bearing in mind the unique properties of carbon dioxide in the solid state. The results presented show the behavior of dry ice during compression in a rectangular chamber for different final densities of the finished product. As a result, it is possible to determine the values of the Poisson ratio as a function of density, using for this purpose four mathematical models. The findings of this research may be useful for research work focused on the further development of this process, such as by using the Drucker–Prager/Cap numerical model to optimize the geometric parameters of the parts and components of the main unit of the machine used in the extrusion process of dry ice.
Environmental STEM Study of the Oxidation Mechanism for Iron and Iron Carbide Nanoparticles
Authors: LaGrow Alec P. , Famiani Simone , Sergides Andreas , Lari Leonardo , Lloyd David C. , Takahashi Mari , Maenosono Shinya , Boyes Edward D. , Gai Pratibha L. , Thanh Nguyen Thi Kim
Published: February 2022

The oxidation of solution-synthesized iron (Fe) and iron carbide (Fe2C) nanoparticles was studied in an environmental scanning transmission electron microscope (ESTEM) at elevated temperatures under oxygen gas. The nanoparticles studied had a native oxide shell present, that formed after synthesis, an ~3 nm iron oxide (FexOy) shell for the Fe nanoparticles and ~2 nm for the Fe2C nanoparticles, with small void areas seen in several places between the core and shell for the Fe and an ~0.8 nm space between the core and shell for the Fe2C. The iron nanoparticles oxidized asymmetrically, with voids on the borders between the Fe core and FexOy shell increasing in size until the void coalesced, and finally the Fe core disappeared. In comparison, the oxidation of the Fe2C progressed symmetrically, with the core shrinking in the center and the outer oxide shell growing until the iron carbide had fully disappeared. Small bridges of iron oxide formed during oxidation, indicating that the Fe transitioned to the oxide shell surface across the channels, while leaving the carbon behind in the hollow core. The carbon in the carbide is hypothesized to suppress the formation of larger crystallites of iron oxide during oxidation, and alter the diffusion rates of the Fe and O during the reaction, which explains the lower sensitivity to oxidation of the Fe2C nanoparticles.
Effects of Geometry and Loading Mode on the Stress State in Asphalt Mixture Cracking Tests
Authors: Li Yan , Xuan Weian , Rahman Ali , Ding Haibo , Yusupov Bekhzad
Published: February 2022

Currently, a variety of asphalt mixture cracking characterization tests are available as screening tools for the better selection of high-quality raw materials and also for the optimization of mixture design for different applications. However, for a same evaluation index, using different sample geometries and loading modes might lead to obtaining different values, which prevents the application of the evaluation index as a fundamental parameter in pavement design. In this paper, the effects of geometry and loading mode on the stress state in the experimental characterization of asphalt mixture cracking were discussed using numerical simulation. The results showed that applying thermally-induced load in restrained uniaxial test configuration should be considered when performing an asphalt mixture cracking test. Compared with direct tensile configuration, compressive stress clearly existed in other common test configurations, which may prevent the initiation and propagation of cracks. Moreover, it was revealed that nonuniform stress state exists in the dog-bone geometry, which makes it possible to know the failure plane in advance and place gauges at the failure plane for measuring fundamental deformation-related properties.