bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality of Chatbot Information Related to Benign Prostatic Hyperplasia
Authors: Warren Christopher J. , Payne Nicolette G. , Edmonds Victoria S. , Voleti Sandeep S. , Choudry Mouneeb M. , Punjani Nahid , Abdul‐Muhsin Haider M. , Humphreys Mitchell R.
Published: November 2024

Background

Large language model (LLM) chatbots, a form of artificial intelligence (AI) that excels at prompt‐based interactions and mimics human conversation, have emerged as a tool for providing patients with information about urologic conditions. We aimed to examine the quality of information related to benign prostatic hyperplasia surgery from four chatbots and how they would respond to sample patient messages.

Methods

We identified the top three queries in Google Trends related to “treatment for enlarged prostate.” These were entered into ChatGPT (OpenAI), Bard (Google), Bing AI (Microsoft), and Doximity GPT (Doximity), both unprompted and prompted for specific criteria (optimized). The chatbot‐provided answers to each query were evaluated for overall quality by three urologists using the DISCERN instrument. Readability was measured with the built‐in Flesch–Kincaid reading level tool in Microsoft Word. To assess the ability of chatbots to answer patient questions, we prompted the chatbots with a clinical scenario related to holmium laser enucleation of the prostate, followed by 10 questions that the National Institutes of Health recommends patients ask before surgery. Accuracy and completeness of responses were graded with Likert scales.

Results

Without prompting, the quality of information was moderate across all chatbots but improved significantly with prompting (mean [SD], 3.3 [1.2] vs. 4.4 [0.7] out of 5; p < 0.001). When answering simulated patient messages, the chatbots were accurate (mean [SD], 5.6 [0.4] out of 6) and complete (mean [SD], 2.8 [0.3] out of 3). Additionally, 98% (39/40) had a median score of 5 or higher for accuracy, which corresponds to “nearly all correct.” The readability was poor, with a mean (SD) Flesch–Kincaid reading level grade of 12.1 (1.3) (unprompted).

Conclusions

LLM chatbots hold promise for patient education, but their effectiveness is limited by the need for careful prompting from the user and by responding at a reading level higher than that of most Americans (grade 8). Educating patients and physicians on optimal LLM interaction is crucial to unlock the full potential of chatbots.
Localized Amino Acid Enrichment Analysis as a Tool for Understanding Protein Extremophilicity
Authors: Hill Elliot , Hill Avery , Voisin Elena , Byrd Amber , Schoeffler Allyn
Published: November 2024

Sequence conservation analyses offer us a powerful glimpse of natural selection at work. Standard tools for measuring sequence conservation report conservation as a function of a specific location in a multiple sequence alignment and have proven indispensable in identifying highly constrained features such as active site residues. The advent of large‐scale genomic sequencing efforts allows researchers to expand this paradigm and investigate more nuanced relationships between sequence and function. Here, we present a simple tool (SWiLoDD: Sliding Window Localized Differentiation Detection) that allows researchers to analyze local, rather than site‐specific, conservation using a sliding window approach. Our tool accepts multiple sequence alignments partitioned based on a biological differentiator and returns alignment position‐based, localized differential enrichment metrics for amino acids of choice. We present two case studies of this analysis in action: local‐but‐diffuse glycine enrichments in the ATPase subunits of thermophilic and psychrophilic bacterial gyrase homologs, and ligand‐ and interface‐specific amino acid enrichments in halophilic bacterial crotonyl‐CoA carboxylases/reductases. Though we have described examples of extremophilic bacterial proteins in this study, our tool may be used to investigate any set of homologous sequences from which sub‐groups can be meaningfully partitioned. Our results suggest that investigating differential localized conservation in partitioned MSAs will expand our understanding of how sequence conservation and protein function are connected.
Experiences of Losing and Re‐Establishing a ‘Sense of Place’: Insights From Forced Resettlement in Myanmar
Authors: Cornish Gillian E.
Published: November 2024

Forced resettlement, the process of intentionally displacing and moving people from one location to another, increases impoverishment risks and creates severe and long‐lasting economic and psycho‐socio‐cultural impacts. While these impacts are well established, there is comparatively much less research about ‘loss of place’ after displacement when people are disconnected from a space or spaces that are meaningful to them. Therefore, this paper seeks to address this gap through empirical research on the experiences of residents who were displaced and relocated to an outer township in Yangon, Myanmar, 25 years after the resettlement event. The study examines what it means to lose a sense of place after forced resettlement, and how despite the disorientating impacts of displacement, individuals actively worked to re‐establish social and physical connections over time. The paper outlines how displaced residents developed and implemented strategies to re‐establish their sense of place and rebuild their community. It finds that multiple levels of strategies were developed—at individual, household, and community scales—to restore social connections and adapt to a new environment. These findings contribute to a deeper understanding of place attachment and community rebuilding, particularly in contexts where displacement is driven by urban development, climate change, or state interventions.
Quantitative pulmonary perfusion in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension
Authors: Hansen Jacob V. , Poulsen Mette W. , Nielsen‐Kudsk Jens E. , Kalra Mannudeep K. , Lyhne Mads D. , Andersen Asger
Published: November 2024

Current methods for quantifying perfusion from computed tomography pulmonary angiography (CTPA) often rely on semi‐quantitative scoring systems and requires an experienced evaluator. Few studies report on absolute quantitative variables derived from the images, and the methods are varied with mixed results. Dual‐energy CTPA (DE‐CTPA) enables automatic quantification of lung and lobar perfusion with minimal user interaction by utilizing machine learning based software. We aimed to evaluate differences in DE‐CTPA derived quantitative perfusion variables between patients with acute pulmonary embolism (PE) and chronic thromboembolic pulmonary hypertension (CTEPH). This retrospective, single‐center, observational study included 162 adult patients diagnosed with PE (n = 81) or CTEPH (n = 81) and scanned using dual‐energy CT between 2020 and 2023. Mann–Whitney U tests and permutational analysis of variance (PERMANOVA) were used for comparative analyses. We found whole lung perfusion blood volume to be lower (p < 0.001) in PE patients (median 3399 mL [2554, 4284]) than in CTEPH patients (median 4094 mL [3397, 4818]). The same was observed at single lung and lobar level. PERMANOVA encompassing all perfusion variables showed a difference between the two groups (F‐statistic = 13.3, p = 0.002). Utilizing logistic regression, right and left lower lobe perfusion blood volume showed some ability to differentiate between PE and CTEPH with area under the receiver operation characteristics curve values of 0.71 (95% CI: 0.56; 0.84) and 0.72 (95% CI: 0.56; 0.86). Pulmonary perfusion is lower in patients with PE than patients with CTEPH, highlighted by differences in DECT‐derived perfusion blood volume. Quantitative perfusion variables might be useful to differentiate between the two diseases.
Delta‐like ligand 4 inhibitor drug treatment induces pulmonary hypertension in cancer clinical trials
Authors: Besse Casandra E. , Winicki Nolan M. , Puerta Cristian , Hernandez Moises , Yuan Jason X.‐J. , Thistlethwaite Patricia A.
Published: November 2024

Delta‐like ligand 4 (DLL‐4) inhibitor drugs are an emerging cancer treatment. In clinical trials for solid organ malignancies, intravenous administration of monoclonal antibodies that inhibit DLL‐4 is associated with development of pulmonary hypertension, in the absence of left ventricular dysfunction. Analysis of 13 clinical trials showed that pulmonary hypertension is a complication of DLL‐4 inhibition.
Robust Shared Control With Stable Contact Servoing for Enhanced Object Transportation by Telerobotic Bimanual Mobile Manipulators
Authors: Teng Tao , Wu Xi , Li Zhihao , Caldwell Darwin , Chen Fei
Published: November 2024

Bimanual mobile manipulation significantly enhances the capabilities of field robots that interact with diverse dynamic environments and expands the range of possible manipulation actions. This paper introduces a robust shared control architecture for remote manipulation of the Collaborative Dual‐arm Robot Manipulator (CURI), aimed at stable object transportation. Given that stable contact is pivotal for successful object transportation, our focus is on stabilizing the contact between the robot end‐effectors and the object using a contact servoing strategy. To maintain stable contact, it is essential that the contact wrenches consistently stay within the predefined friction cones throughout the task. We propose a novel shared control strategy to stabilize the contact using the contact parameterization model. This model formulates the contact stability manifold using a set of unconstrained reparameterized variables through a bijective mapping function, ensuring that the controller derived from these unconstrained reparameterized variables consistently maintains contact stability. The efficacy of the proposed approach is convincingly demonstrated through a series of experiments involving representative bimanual transportation tasks within a logistics context. Both theoretical analysis and experimental validations confirm that our proposed control strategy not only ensures the stable transportation of objects by CURI but also substantially enhances the overall robustness of the shared control system.
Near real‐time monitoring of wading birds using uncrewed aircraft systems and computer vision
Authors: White Ethan P. , Garner Lindsey , Weinstein Ben G. , Senyondo Henry , Ortega Andrew , Steinkraus Ashley , Yenni Glenda M. , Frederick Peter , Ernest S. K. Morgan
Published: November 2024

Wildlife population monitoring over large geographic areas is increasingly feasible due to developments in aerial survey methods coupled with the use of computer vision models for identifying and classifying individual organisms. However, aerial surveys still occur infrequently, and there are often long delays between the acquisition of airborne imagery and its conversion into population monitoring data. Near real‐time monitoring is increasingly important for active management decisions and ecological forecasting. Accomplishing this over large scales requires a combination of airborne imagery, computer vision models to process imagery into information on individual organisms, and automated workflows to ensure that imagery is quickly processed into data following acquisition. Here we present our end‐to‐end workflow for conducting near real‐time monitoring of wading birds in the Everglades, Florida, USA. Imagery is acquired as frequently as weekly using uncrewed aircraft systems (aka drones), processed into orthomosaics (using Agisoft metashape), converted into individual‐level species data using a Retinanet‐50 object detector, post‐processed, archived, and presented on a web‐based visualization platform (using Shiny). The main components of the workflow are automated using Snakemake. The underlying computer vision model provides accurate object detection, species classification, and both total and species‐level counts for five out of six target species (White Ibis, Great Egret, Great Blue Heron, Wood Stork, and Roseate Spoonbill). The model performed poorly for Snowy Egrets due to the small number of labels and difficulty distinguishing them from White Ibis (the most abundant species). By automating the post‐survey processing, data on the populations of these species is available in near real‐time (<1 week from the date of the survey) providing information at the time scales needed for ecological forecasting and active management.
Estimation and analysis of vegetation parameters for the water cloud model
Authors: Qin Xiangdong , Pang Zhiguo , Lu Jingxuan
Published: November 2024

The Water Cloud Model (WCM) plays a crucial role in active microwave soil moisture inversion applications. Empirical parameters are important factors affecting the accuracy of WCM simulation, but the current evaluation of empirical parameters only considers the forward simulation process, and insufficient consideration is given to the model inversion problem. This study proposes a new estimation method for vegetation parameters in the WCM by combining the soil backscattering model and the objective function. The effectiveness of the method is then verified using measured data. Simultaneously, this study also analyzes the factors influencing the evaluation of vegetation parameters in the WCM, resulting in the following conclusions. First, blindly utilizing vegetation parameters recommended by previous model studies is not advisable. To ensure the accuracy of the simulation, it is necessary to adjust the vegetation parameters appropriately. Second, to ensure the ability of the WCM solving both forward and inverse problems, it is advisable to consider both soil backscatter and surface backscatter simulations in the construction of the cost function. Third, soil backscatter simulations have an impact on the solution of vegetation parameters, and more accurate soil scattering models provide a better representation of the modeled vegetation. This study presents a dependable method for resolving the vegetation parameters of the WCM, thereby offering a valuable reference for the application of the model in surface parameter inversion research.
Integrating social vulnerability to flood risk assessment in Metro Manila
Authors: Dulawan Judy Marie T. , Imamura Yoshiyuki , Amaguchi Hideo
Published: November 2024

This study applied the interaction of social vulnerability and hazard to assess flood risk in three urbanized areas within the Pasig‐Marikina‐Laguna‐Lake catchment: Manila, Marikina, and Parañaque in Metro Manila, Philippines. This study examined risk patterns across different flood return periods (5, 50, and 100 years) in these urban river environments and provided both city‐wide and localized risk assessments. The social vulnerability to flood index (SVFI) was calculated using socioeconomic indicators, while the hazard index was derived from flood depth categories. Results show that city‐level risk indices are low to moderate, with Marikina consistently having the highest risk, followed by Manila and Parañaque. However, localized assessments reveal high‐risk areas within cities, with Manila being the most vulnerable to frequent floods (5‐year return period) and Marikina to less frequent but extreme events (50‐ and 100‐year return periods). Parañaque maintains the lowest risk profile across all scenarios. This study highlights the importance of considering both citywide trends and localized high‐risk areas in flood risk management. It provides valuable insights for disaster management planners and policymakers, enabling the development of targeted strategies for sustainable urban river management and flood risk reduction in rapidly urbanizing river systems. The methodology presented applies to other urban areas that face similar flood risks.
Folic Acid‐Mediated Reduction‐Sensitive Curcumin Prodrug Enhances the Delivery Performance of Curcumin in Liver Cancer Cells
Authors: Lin Yang , Liang Ju , Wu Wenlan , Zhang Yunyun , Yan Fuqing
Published: November 2024

In order to improve the delivery performance of curcumin (CUR) in liver cancer cells, we prepared a targeted and reduction‐sensitive prodrug, folic acid‐polyethylene glycol‐disulfide bond‐curcumin (FA‐PEG‐SS‐CUR). The synthesis involved the conjugation of CUR with NH2‐PEG‐NH2 through a disulfide bond, followed by the connection of CUR‐SS‐PEG‐NH2 to FA‐COOH via acylation. The resultant FA‐PEG‐SS‐CUR prodrug self‐assembled into nano micelles in aqueous solutions, displaying excellent dispersibility with an approximate particle size of 119 nm. In vitro drug release studies demonstrated the sensitivity of FA‐PEG‐SS‐CUR to glutathione (GSH), displaying sustained release performance. After 72 h, FA‐PEG‐SS‐CUR exhibited a drug release rate of 38% at low GSH concentration and 59% at high GSH concentration. Notably, FA‐PEG‐SS‐CUR micelles exhibited favorable biocompatibility. The hemolysis rate resulting from co‐incubation with red blood cells remained below 3%. Furthermore, cytotoxicity experiments unveiled the substantial cytotoxicity of FA‐PEG‐SS‐CUR micelles against HepG2 tumor cells. Cellular uptake studies confirmed the greater internalization of FA‐PEG‐SS‐CUR by HepG2 cells compared to the non‐targeted PEG‐SS‐CUR. The findings highlight the potential of FA‐PEG‐SS‐CUR as an ideal drug delivery system for CUR due to its facile synthesis and strong self‐assembly performance.
Ferrocenyl Aminocresols Display Multimodal Activity Against Triple‐Negative Breast Cancer Cells In Vitro
Authors: Mhlanga Richwell , Mbaba Mziyanda , Tonui Ronald , Edkins Adrienne L. , Khanye Setshaba D. , de la Mare Jo‐Anne
Published: November 2024

Triple‐negative breast cancer (TNBC) lacks expression of the oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu), has an aggressive tumor phenotype, shows only a partial response to chemotherapy, and lacks clinically established targeted therapies. Therefore, there is a need to develop more effective drugs for the treatment of TNBC. The ferrocenyl benzoxazine and α‐aminocresols class of compounds gave a potential source of multimodal inhibitors of cancer based on previous studies. In this study, a set of ferrocenyl benzoxazines and α‐aminocresols were screened and characterized as potential inhibitors of TNBC in vitro. A panel of 11 compounds was screened for selective cytotoxicity to cancer cells over normal cell equivalents. Focusing on the previously proposed modes of action of their building blocks, α‐aminocresols 3a and 3b exhibited significant DNA binding capabilities and caused robust DNA damage in TNBC cells. In addition, both compounds exhibited significant ROS generation capability; however, introducing a ROS quencher in a cell viability assay only partially rescued the cells from the cytotoxicity effects of the α‐aminocresols. This, together with the observation that compounds 3a and 3b triggered significant protein aggregation in HCC1806 cells, supports a mixed mode of action for these compounds.
A Mixed‐Pure Planar Heterojunction Structure of Active Layers for Efficient Sequential Blade‐Coating Organic Solar Cells
Authors: Wang Yilin , Tang Yabing , Ouyang Yanni , Wu Weiwei , Patterson Acacia , Alqahtani Obaid , Melody Tanner , Zhou Ke , Lu Guanghao , Min Jie , Zhang Chunfeng , Yan Han , Fan Qunping , Jiang Long , Collins Brian A. , Ma Wei
Published: November 2024

Precise modulating the vertical structure of active layers to boost charge transfer is an effective way to achieve high power conversion efficiencies (PCEs) in organic solar cells (OSCs). Herein, efficient OSCs with a well‐controlled vertical structure are realized by a rapid film‐forming method combining low boiling point solvent and the sequential blade‐coating (SBC) technology. The results of grazing incident wide‐angle X‐ray scattering measurement show that the vertical component distribution is varied by changing the processing solvent. Novel characterization technique such as tilt resonant soft X‐ray scattering is used to test the vertical structure of the films, demonstrating the dichloromethane (DCM)‐processed film is truly planar heterojunction. The devices with chloroform (CF) processed upper layer show an increased mixed phase region compared to these devices with toluene (TL) or ‐DCM‐, which is beneficial for improving charge generation and achieving a superior PCE of 17.36%. Despite significant morphological varies, the DCM‐processed devices perform slightly lower PCE of 16.66%, which is the highest value in truly planar heterojunction devices, demonstrating higher morphological tolerance. This work proposes a solvent‐regulating method to optimize the vertical structure of active layers through SBC technology, and provides a practical guidance for the optimization of the active‐layer microstructure.
Interfacial Electric Field Enhanced Free‐Standing VO2/rGO Aerogel Anode with Ultra High Mass Energy Density for Aqueous Ammonium Ion Battery
Authors: Gong Jia'ni , Bai Pengfei , Zhang Yifu , Zhou Zhenhua , Wang Qiushi , Lv Haifeng , Hu Tao , Wu Xiaojun , Meng Changgong
Published: November 2024

Aqueous batteries have become a promising means of energy storage due to its environmental friendliness. Nevertheless, it often exhibits limited energy density that hinder their application. Considering that ammonium ion (NH4+) has a low mass and a small hydration radius, aqueous ammonium ion batteries (AAIBs) are expected to solve the problem of low energy density. Herein, we obtain Vanadium dioxide/reduced graphene oxide aerogel (VOGA) by in‐situ growth of VO2 on the graphene surface for interfacial electric field enhanced AAIBs to achieve high mass energy density. The VOGA free‐standing electrode achieves a specific capacity of up to 655 mA g−1 at a current density of 0.5 A g−1. And the mass energy density of the VOGA.
Effect of Nb Content on the Abnormal Grain Growth in 20MnCr5 Hot‐Rolled Bar
Authors: Dai Zhipeng , Yang Jian , Zhang Qingsong , Bai Yun , Lu Mingxia , Wang Xuhui , Zhang Yuqi
Published: November 2024

In the present article, the abnormal grain growth behavior of 20MnCr5 hot‐rolled bars with microalloying of 0.0198 wt% niobium low‐Nb steel (LNb) and 0.0241 wt% niobium high‐Nb steel (HNb) are investigated after heat treatment at 960 °C for 4 h. The radius of the hot‐rolled bars is 22.5 mm and the results show that the mixed grain region in LNb hot‐rolled bar is with a radius ranging from 9.5 to 22.5 mm, while the mixed grain region in HNb hot‐rolled bar is with a radius of 20 to 22.5 mm. The main precipitates are AlN and NbC, particles, and their composite precipitates. In LNb and HNb, the precipitates in outer region 1 are larger than those in inner region 3, and the number density is less. In the same region, the particle size of precipitates in LNb is larger than that in HNb, and the number density is much lower. Therefore, the mixed grains appear near the outer region of the experimental steels, and the mixed grain phenomenon of LNb is more serious than that of HNb.
Fe3O4@Pectin@Acetamide for Magnetic Solid Phase Extraction of Some Parabens in Cosmetic Samples and Their Quantification by High‐Performance Liquid Chromatography‐Ultraviolet Detection
Authors: Nikbakhsh Naghmeh , Ghani Milad , Maleki Behrooz
Published: November 2024

In this project, the in‐situ formation of magnetic nanoparticles modified with pectin and acetamide was presented and used as a sorbent in the magnetic solid‐phase extraction method. The synthesis of the magnetic sorbent was studied by various characterization methods. The sorbent was employed for the microextraction of four model analytes including methyl paraben, ethyl paraben, propyl paraben, and butyl paraben. The separation and measurement of the extracted compounds were done by high‐performance liquid chromatography‐ultraviolet detection. In order to achieve the best extraction condition, factors affecting the extraction efficiency were investigated and optimized using response surface methodology. In the obtained optimized condition, the following parameters were achieved: limits of detection: 0.16–0.28 µg/L, limits of quantification: 0.49–0.92 µg/L, and intra‐ and inter‐day relative standard deviations: 1.2%–6.6% and 1.6%–4.8%, respectively. The linear dynamic ranges of the method for methyl paraben, ethyl paraben, butyl paraben, and propyl paraben were 1–200, 0.5–500, 1–500, and 1–500 µg/L, respectively. In order to investigate the effectiveness of the method, the proposed magnetic nanosorbent was used to measure the desired parabens in cosmetic samples. The results showed good accuracy and precision of the developed method for the determination of trace amounts of target analytes.
Ultrasound assessment of lymph nodes for staging of gynecological cancer: consensus opinion on terminology and examination technique
Authors: Fischerova D. , Gatti E. , Culcasi C. , Ng Z. , Szabó G. , Zanchi L. , Burgetova A. , Nanka O. , Gambino G. , Kadajari M. R. , Garganese G. ,   Collaborators
Published: November 2024

The lymphatic pathway is an important route of metastasis in gynecological malignancy. Therefore, the examination of lymph nodes is an essential part of the ultrasound evaluation in patients with known or suspected gynecological malignancy. The lymph nodes most frequently involved in gynecological malignancy (apart from vulvar cancer) are parietal (retroperitoneal) and visceral abdominopelvic lymph nodes. In advanced disease, more distant lymph‐node regions, such as the inguinal, axillary and supraclavicular lymph nodes, can also be involved. The standardized description of lymph nodes has been published previously by the Vulvar International Tumor Analysis (VITA) collaborative group. Herein, a collaborative group of gynecologists and gynecological oncologists with extensive ultrasound experience presents a systematic methodology for ultrasonographic lymph‐node assessment performed as part of the locoregional and distant work‐up to assess the extent of gynecological malignancy. The aim of this consensus opinion is also to describe the anatomical classification and drainage pathways of the lymphatic system as relevant to the gynecological organs. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Factors affecting marriage and pregnancy/childbirth among women physicians in Japan
Authors: Kawase Kazumi , Adachi Tomoko , Nagoshi Sumiko , Kido Michiko , Nomura Kyoko
Published: November 2024

Background

Previous studies have not elucidated the factors affecting marriage and pregnancy/childbirth. This study identifies whether work characteristics and conditions affect marriage and pregnancy/childbirth among women physicians.

Methods

This nationwide survey was conducted on women members of three major Japanese medical societies: internal medicine, obstetrics and gynecology, and surgery.

Results

A total of 7747 women participated in this study. Although the mean age at marriage was the same, the age at the first childbirth in all specialties, especially in surgery, was significantly higher than that for the general Japanese population. In addition, being in a junior position, being board‐certified, and working in a workplace other than a university hospital were positively associated with the experience of pregnancy/childbirth, whereas working hours showed no impact.

Conclusions

We should change the mindset regarding pregnancy/childbirth and build effective strategies in academic institutions to improve the environment for safer pregnancy/childbirth while advancing careers.
Properties of Eco-Cement Blocks Made with Polymer Wastes and Graphene
Authors: Calderón Verónica , Arroyo Raquel , Alía Cristina , Garijo Lucía , González-Moreno Sara
Published: November 2024

The inclusion of polyurethane wastes as recycled and reusable materials to replace variable amounts of aggregates is interesting in the production of new construction materials due to their final properties. In this research, the effects of waste polymer replace by sand (25%) and graphene oxide on mortars (0.5, 1, 1.5, 2, 2.5 y 3% with respect to the cement) have been investigated. To maintain and even improve the final properties, graphene oxide modify aspect as thermal conductivity and electrical properties, water behavior, mechanical properties and final contribution to fire.
Optimization of Tire Rubber-Concrete Core Materials for Application in New Sandwich-Structured Cementitious Composites
Authors: Sambucci Matteo , Gullo Giulia , Valente Marco
Published: November 2024

Implementing tire rubber-concrete mixtures to produce sandwich-structured cementitious composites can represent an attractive route in the perspective of lightweight design, energy efficiency, and sustainability for the building and construction industry. This work deals with a DOE multi-response optimization study on rubber-concrete mixes designed with different proportions of fine and coarse rubber aggregates to achieve the best formulation to be applied in the manufacturing of cementitious sandwich composites. The “sand-free” concrete mixture made up of 70% of rubber powder and 30% of rubber granules was optimal in terms of mechanical properties, physical characteristics, and thermo-acoustic insulation behavior. Sandwich-structured composite incorporating the optimum mix as a core layer showed significant improvement in terms of flexural performance over the monolithic rubberized materials and strength value in the range of RILEM “class II” lightweight construction materials.
Carbon Footprint and CO2 Emissions in the Concrete-Polymer Composites Technology
Authors: Sokołowska Joanna Julia , Chmielewska Bogumiła
Published: November 2024

In the building materials industry, similarly to other industry sectors, the quantification of greenhouse gas emissions is undertaken, enabling the identification of GHG sources both for individual production processes and in total – for specific material solutions and products. While recently a lot of attention is paid to analyze carbon footprint of ordinary concrete and development of low-emission cements with significantly reduced Portland clinker content, the issue of GHG quantification in the context of concrete-like polymer composites (including concretes with polymer binders e.g. PCC or PC and concretes with significant amounts of polymer modifiers) is not recognized. This article attempts to make a preliminary assessment of the impact of the presence of polymers on the carbon footprint of such composites.
The Role of Polymer in Calcium Sulfoaluminate Cement-Based Materials
Authors: Wang Ru
Published: November 2024

In order to realize sustainable development, new types of cements were paid more attention. Calcium sulfoaluminate (CSA) cement is a kind of eco-friendly cement that has the characteristics of low carbon emission, low energy consumption, fast setting and hardening, and so on. But the main hydration product ettringite (AFt) is quite sensitive to curing conditions that makes CSA cement-based materials sensitive to temperature and ageing. Polymer plays a key role in improving the properties of CSA cement mortar. Our researches showed that styrene-butadiene copolymer (SB) could result in a big reduction of zeta potential and conductivity of the CSA cement paste, retard the very initial hydration of CSA cement but not after 3 h, and lead to the generation of more AFt and aluminium hydroxide (AH3). With SB addition increasing, the yield stress, viscosity, thixotropy, fluidity and thus workability of CSA cement mortar were significantly improved. The mechanical strength of CSA cement mortar showed a reduction after a certain age, but when SB was added there was no reduction anymore under various curing conditions. SEM observation of the morphology accounts well for the changes in mechanical properties. The shrinkage, water capillary adsorption, and durability such as resistance to freezing and thawing cycle, carbonization and sulfate attack were also investigated. This paper reviewed the role of polymer in CSA cement-based materials taking SB as an example based on recent research work of our group.
Study and Characterization of Gypsum Mortars Made with Phenolic Melamine Polymer Wastes from the Decorative Paper Industry
Authors: Santamaría-Vicario Isabel , Zurro-García Belén , Paredes-Núñez Ana María , Petrement Carlos Junco , Saiz Ángel Rodríguez
Published: November 2024

The proposed research studies the properties of gypsum mortars made with polymeric waste from the manufacturing process of high pressure laminated (HPL) thermosetting decorative panels, composed of cellulose paper layers impregnated with phenolic resins and melamine resins. The waste generated in the cutting, profiling and milling of the decorative panels is discarded and sent to landfill without a defined use. This research aims to contribute to the Circular Economy of Waste by recovering it as a raw material. Gypsum mortars are designed by adding different amounts of melamine waste. Subsequently, the properties of the mortars are studied following the technical prescriptions established in the European regulations. Firstly, the properties of the mortars in their fresh state are studied, such as the water/gypsum ratio, consistency, apparent density of the fresh mortar and setting time. Then, the properties of the hardened mortars are determined, such as the apparent density of the hardened mortar, mechanical resistance to bending and compression, adhesion, Shore C surface hardness and capillary absorption. Based on the results obtained in the tests, the viability of this type of waste is assessed for its use as a mineral aggregate to replace traditional aggregates, in order to obtain commercial gypsum mortars for use in masonry work, cladding, walls, or as a raw material for the manufacture of prefabricated materials. The results obtained show that the limit of gypsum substitution by melamine waste could be a maximum of 25%. New mortar formulations with lower substitutions would provide significant advantages in this type of ecological materials, in accordance with the technical requirements established by the applicable European regulations.
Valorisation of Polyurethane Waste in Gypsum Mortar to Improve Its Circular Economy
Authors: Rodrigo-Bravo Alba , Gutiérrez-González Sara , Carpintero Verónica Calderón , Cuenca-Romero Lourdes Alameda
Published: November 2024

The study of the behaviour of polymeric waste in building materials is of great interest. Both sectors are important and have a significant impact on the environment, so more sustainable alternatives that drive the circular economy are needed. A multi-criteria assessment on gypsum mortar with polyurethane waste from eight different industries has been carried out to analyse in depth the influence of this polymer on building materials. The methodology used studies the physico-mechanical properties of the mixtures. A “cradle to gate” Life Cycle Assessment at laboratory level is also included to evaluate and compare their environmental performance. The dosage evaluated is the one that recovers the greatest amount of waste possible while maintaining its performance above the values established in the regulation. The results of the study show that the incorporation of polyurethane waste in gypsum mortars decreases their bulk density by 2–22% in the fresh state and 7–24% in the hardened state, while flexural and compressive strengths are reduced by about one third. The environmental impact assessment of the innovative materials shows that some samples are 15–22% more environmentally friendly than the conventional one. It is concluded that the incorporation of polyurethane waste in gypsum mortar products is a viable alternative to landfill disposal or incineration, given its good technical and environmental performance.
Construction Versus Circular Economy
Authors: Tomaszewska-Krygicz Justyna
Published: November 2024

Closing the loop of materials circulation is certainly the right way to decrease the pressure humans place on the environment. Although many efforts have been made toward effective mitigation of anthropogenic impacts, mostly on the policy dimension, there is still much more to do. The transformation affects every phase of the building’s lifecycle, which therefore requires the engagement of all value chain actors and suppliers, often assigning them new roles and responsibilities. The experiences gained from over a decade of the EU’s journey towards CE clearly indicate that, regardless of how good the legal regulations are and how effective the educational efforts are, achieving the goals of maintaining resources in the economy is not possible without the implementation of innovation and proper business models. Considering that materials and resources marketplaces are among the most common areas of Contech investment, it is worth considering what role polymer concrete composites (CPC) may play in the sector's quest for circularity. This article will try to find an answer to this dilemma by discussing the meaning of CE for the sector, its main drivers, and implications for the supply chain.
Chloride Diffusion and Mechanical Performances of Geopolymer Concrete with Blended Precursor
Authors: Duży Patrycja , Hager Izabela , Choińska-Colombel Marta , Amiri Ouali
Published: November 2024

Geopolymer concrete is an environment-friendly material and is presently accepted as an alternative to conventional concrete. It utilizes industrial by-products like fly ash and slag to reduce CO2 emissions associated with cement production. Despite being investigated over the decades, the application of geopolymers in construction is still very limited. Most of the research data refer to geopolymer pastes and mortars and their properties, performances, and durability. Although geopolymer concretes are well-accepted in the research community owing to their comparable or even better performances as a cement substitution.

In this paper, the precursors for geopolymer concrete preparations are blends of fly ash (FA) and ground granulated blast-furnace slag (GGBFS) in three slag proportions: 5%, 20%, and 35% expressed as a percent of FA mass. The concretes were denominated AAC5, AAC20, and AAC35, respectively. Their basic physical and mechanical characteristics were investigated, as were their transport properties of chloride ions. The ASTM C1556 test was applied to determine the chloride ions’ penetration of the geopolymers. The measurements revealed a strong dependence between chloride penetration through the concrete and the precursor composition.
The Effects of Calcium and Phosphate Compounds on the Mechanical and Microstructural Properties of Fly Ash Geopolymer Mortars
Authors: Prochoń Piotr , Piotrowski Tomasz , Courard Luc , Zhao Zengfeng
Published: November 2024

Phosphorus and calcium compounds are present in the chemical composition of byproducts from coal and biomass combustion. They may have an influence on the microstructure and the mechanical properties through the specific bonds in polymeric aluminosilicates - geopolymers. Results proved that the 5% of CaO added to high-silica fly ash geopolymer increases material density and mechanical properties. Phosphate compounds available in the biomass fly ash have a negative effect on geopolymer mortars by increasing porosity and decreasing their compressive strength.
Effect of Polymer Mortar Modification Using Eco-friendly Biochar on Microstructure
Authors: Załęgowski Kamil , Kępniak Maja
Published: November 2024

The construction sector should have much to offer in terms of helping to achieve circular economy goals, among others the use of waste materials. The example of such materials is biochar, a black porous and carbon-rich matter that could be converted from various waste biomass. A biochar could be utilized as microfiller in polymer concretes. This application of biochar is promising due to good interfacial bonding with polymer, no reactivity between surrounding polymer matrix and filler particles and fact that even fillers with irregular particles and large specific surface area could be utilized in polymer matrix. These create real opportunity to effectively dispose waste materials as a replacement of natural aggregates in polymer concrete technology. The presented paper is a second part of the research concerning the utilization of ecofriendly biochar in polymer composites conducted by authors. To better understand the impact of modification by biochar, already performed tests were supplemented by measurements of ultrasonic pulse velocity and quantitative analysis of microstructure.
Effect of Polymer Content on Properties of Polymer Cement Mortar
Authors: Demura Katsunori , Saito Toshikatsu
Published: November 2024

In this paper, the volume fraction of polymer as a solid in the polymer cement mortar (PCM) is defined as the polymer content. The effect of the polymer content on the properties such as the flexural and compressive strengths, water permeability, carbonation and chloride ion penetration of PCM is discussed. As a result, the equation of the effective factor (F) for the properties of the PCM by using the water-cement ratio (W/C), polymer content (Vp), and volume fractions of air (Va) and sand (Vs) is established as “F = (1-W/C)(1 + AVp)(1-Va)(1 + 5Vs)”. The empirical constant (A) is the 4, -6, -8, -6 and -4 for the flexural strength, compressive strength, water permeability, carbonation depth and chloride ion penetration depth of PCM, respectively. The equation for estimating the properties of PCM by using the effective factor and the properties of cement mortar (Plain) is established as “P

P
 = B(FP

0
) + C”. Where, P

P
, F, and P

0
are the properties of PCM, the effective factor and the properties of Plain with the same W/C, sand-cement ratio and curing condition as the PCM. The empirical constants B and C in this equation are depending on the type of polymer used and curing condition.
Effect of Polymer Paste Content on the Porosity and Strength of Pervious Polymer Concrete
Authors: Yeon Jung Heum , Choi Yeoung-Geun , Yang Cheol-Jae , Yeon Kyu-Seok
Published: November 2024

This study investigates the effect of polymer paste content on the porosity and strength of pervious polymer concrete made of unsaturated polyester resin, fly ash filler, and crushed coarse aggregate. The porosity (total porosity and connected porosity) and strength (compressive and flexural strengths) for different polymer paste contents were investigated. The polymer paste content was chosen as an experimental variable because it determines the cost-effectiveness and has a significant impact on various material properties. The results showed that the total and connected porosity fell between 37.5–8.8% and 34.2–7.2%, respectively, when the polymer paste content increased from 7 to 19.5 wt.%. The porosity tended to decrease as the polymer paste content increased. The compressive and flexural strengths ranged from 14.5 to 41.5 MPa and 4.3 to 16.1 MPa, and the strengths increased as the paste content increased. In particular, the strengths were much higher than those of many existing studies on conventional portland cement concrete due to the enhanced adhesion of the polymer binder upon the addition of the cross-linking agent.
Study on the Use of Glass By-Products for Sustainable Polymer-Modified Mortars
Authors: Žižková Nikol , Hodul Jakub , Drochytka Rostislav
Published: November 2024

This investigation is focused on the observation of changes in the properties of polymer-modified cement mortars caused by the addition of recycled glass. The current requirements for reducing CO2 emissions in the production of cement composites, are also forcing the producers of polymer-modified mortars (PMMs) to use alternative materials, such as silica-rich supplementary materials. Selected types of recycled glass with pozzolanic behavior were specifically ground (particle size below 63 μm) and used as a partial cement substitute (10 wt.%, 20 wt.% and 30 wt.% substitution of Portland cement). In order to explain the obtained results and garner new knowledge of the microstructure of the mixtures being studied, the following tests were performed: scanning electron microscopy (SEM) observation, differential thermal analysis (DTA) and high-pressure mercury intrusion porosimetry. The findings show that the finely ground recycled glass has high potential to be used as an effective cement replacement for PMM materials, that are currently used in large amounts, mainly in the rehabilitation of concrete structures.
Effects of Polymers and Other Material Components on Electrical Resistivity of Cement Mortar
Authors: Wakasugi Mikio , Fukui Takuya , Kanda Toshiyuki , Demura Katsunori
Published: November 2024

In the repair of the reinforced concrete structures deteriorated due to the chloride corrosion of rebars, it is desirable that the electrical resistivity of the patching repair mortar is equal to or lower than that of the existing concrete, considering the case of adopting the cathodic protection in the future. In general, cementitious patching repair mortars contain polymer components, which are thought to increase the resistivity, but there are also components other than polymer components that affect the resistivity. Such components without polymer include admixture components such as ground granulated blast furnace slag and fly ash, cement components such as ultra rapid hardening cement, and corrosion inhibitor components such as lithium nitrite. In this study, the effects of those components on the resistivity of cementitious patching repair mortars up to the age of 26 weeks are clarified. As a result, the electrical resistivity of cementitious patching repair mortar depends greatly on the types and amounts of their components.
Condition of Circular Economy in Poland
Authors: Falaciński Paweł , Machowska Agnieszka
Published: November 2024

The article covers the state of circular economy implementation in Poland. The consumption of raw materials is presented, as well as indicators of monitoring the transformation of the CE in EU and Poland acc. to the COM/EC, OECD and oto-GOZ project. Poland’s priorities within the circular economy are also presented. They include innovations, markets for secondary raw materials as well as ensuring their high quality and service. The main financial, organizational, social and technological barriers defined. There are a few examples presenting technical solutions implementing the CE in Poland (e.g. building materials, hydraulic binders). The public authorities are recognized as leaders in the implementation of the CE also in the construction sector. Introducing the circular business models is also necessary.
Influence of Aging Condition on the Hydration and Setting Performance of Cement Paste in the Presence of Triethanolamine
Authors: Lu Zichen , Liu Zhiwei , Zhang Liheng , Sun Zhenping
Published: November 2024

Effect of aging conditions on the hydration and setting performance of cement paste with the addition of TEA were investigated through the combined techniques of calorimetry, Vicat test, XRD and TGA. It is found that, along with the increased aging time and RH, an obvious formation of AFt, AFm and CH can be found due to the pre-hydration of clinker. Besides, under the RH of 90%, the pre-hydration within the first day was significantly improved, and this process was continuously developed in the next 7 days through the strong carbonation of CH. Further analysis indicates that the pre-hydration can retard the cement hydration and increase the setting time of cement paste. Compared to the reference, a prolonged induction period and an increased setting time were observed for the aged samples with the addition of TEA. Besides, the commonly observed flash setting performance under the TEA dosage of 0.5 wt.-% was eliminated when the samples were pre-hydrated under 90% RH, which indicates the pre-hydration can alleviate the strongly accelerated aluminate phase hydration caused by TEA.