bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of Methodologies for Managing Energy Flexibility Resources in Buildings
Authors: Pedram Omid , Asadi Ehsan , Chenari Behrang , Moura Pedro , Gameiro da Silva Manuel
Published: August 2023

The integration of renewable energy and flexible energy sources in buildings brings numerous benefits. However, the integration of new technologies has increased the complexity and despite the progress of optimization algorithms and technologies, new research challenges emerge. With the increasing availability of data and advanced modeling tools, stakeholders in the building sector are actively seeking a more comprehensive understanding of the implementation and potential benefits of energy optimization and an extensive up-to-date survey of optimization in the context of buildings and communities is missing in the literature. This study comprehensively reviews over 180 relevant publications on the management and optimization of energy flexibility resources in buildings. The primary objective was to examine and analyze prior research, with emphasis on the used methods, objectives, and scope. The method of content analysis was used to ensure a thorough examination of the existing literature on the subject. It was concluded that multi-objective optimization is crucial to enhance the utilization of flexible resources within individual buildings and communities. Moreover, the study successfully pinpointed key challenges and opportunities for future research, such as the need for accurate data, the complexity of the optimization process, and the potential trade-offs between different objectives.
Improved Analysis of Borehole Heat Exchanger Performance
Authors: Magdic Lucija , Zakula Tea , Boban Luka
Published: August 2023

This paper provides recommendations for improved analyses of the performance of ground-coupled heat pumps. Most research on ground-coupled heat pumps focuses on improving the performance of borehole heat exchangers (BHE) and reducing system costs. However, the potential improvements are mainly assessed at the BHE level rather than considering the entire system incorporating a heat pump, circulation pump, and building needs. This paper shows that such an approach can be misleading, and improvements in BHE are significantly overestimated if the operation of the entire system is not simulated. For instance, improvements in pipe thermal conductivity (from 0.4 to 3 W/(m K)) result in a 7.57% improvement in BHE performance when simulating only a BHE (constant inlet temperature assumed). However, a more realistic simulation of the entire system shows that improvements at a system level are only 0.15%. Other important simulation aspects are also investigated, focusing on different choices regarding the sensitivity analysis method, flow condition type, and optimization strategy. The results suggest that modifications to individual BHE parameters have a limited impact on the overall system performance, while modifying all parameters simultaneously can lead to more significant reductions in total system energy consumption (6% in this study). Furthermore, the research also shows that the potential savings in investment costs (by reducing the borehole depth) outweigh potential savings in operational costs.
Load, Electrification Adoption, and Behind-the-Meter Solar Forecasts for Alaska’s Railbelt Transmission System
Authors: Cicilio Phylicia , Francisco Alexis , Morelli Cameron , Wilber Michelle , Pike Christopher , VanderMeer Jeremy , Colt Steve , Pride Dominique , Helder Noelle K.
Published: August 2023

Load forecasting is an important component of power system and resource planning for electrical grids. The adoption of electric vehicles (EVs), behind-the-meter (BTM) solar, and heat pumps will significantly change the amount and variability of loads. Electrification adoption and load forecasting in arctic regions and Alaska is limited. This paper provides the first load and electrification adoption forecast for the Alaska Railbelt transmission system, including yearly adoption rates of EVs, BTM solar, and heat pumps and hourly load data for the forecasted year of 2050. The adoption rates were based on the available historical data and compared to other regional and national trends. Two forecasts were created: (1) a moderate adoption forecast based on projections from current adoption rates and comparisons to other regional and national projections and (2) an aggressive forecast, which provides an illustrative comparison of a high adoption rate of 90% for all technologies. The results of these forecasts demonstrate a significant increase in both energy, 80% and 116%, and peak load demand, 113% and 219%, for the moderate and aggressive electrification adoption scenarios, respectively. These findings highlight a need for resource planning and demand management in this region due to the adoption of EVs, BTM solar, and heat pumps.
Assessing Tourism Carrying Capacity Based on Visitors’ Experience Utility: A Case Study of Xian-Ren-Tai National Forest Park, China
Authors: Kang Nannan
Published: August 2023

Considering the majority of previous assessment perspectives on tourism carrying capacity are limited by “the number of visitors”, this paper develops an innovative approach from the “visitors’ experience utility” perspective. Using the choice experiment method, tourism carrying capacity is assessed by exploring the marginal utility and sensitivity of visitors to changes in recreational attributes. Xian-Ren-Tai National Forest Park in China is employed as the case park to demonstrate the application of this assessment method. The conclusions are as follows: the carrying capacity threshold of the crowding level in this urban forest park ranges from 20–35 people/100 m2, the threshold of “vegetation coverage” ranges from 70% to 80%, and the “number of garbage” is 3–10 pieces/200 m. The acceptable traffic accessibility level for visitors is within 3 h. At present, Xian-Ren-Tai National Forest Park as a whole is in a state of “low carrying capacity”, there are potential risks of underutilization in this park. In addition, this paper provides the carrying capacity state of 27 potential recreational attribute sets.
Characteristics and Concerns of Logging Businesses in the Southeastern United States: Results from a State-Wide Survey from Alabama
Authors: Bowman Troy , Jeffers Samuel , Naka Kozma
Published: August 2023

A mail survey of Alabama logging firms was conducted in collaboration with the Alabama Loggers Council (ALC) in the spring of 2023 to gather data for current and future assessments of the logging industry’s status and challenges. The response rate was 23.02% after two mailings. The average age of the business respondents was 56 and the average age of employees was 48. About 35% of owners expected to exit the industry within five years, with one-third of those reporting that their business would cease to operate. Most owners who plan to continue operating after five years expect to maintain the same production level. The primary challenges facing logging businesses are increasing operating and equipment costs, the lack of labor and truck drivers, and mill issues (including quotas, shutdowns, and slow operations). COVID-19 has had some effects on Alabama logging operations, including reducing production for a majority of businesses.
Tree Failure Assessment of London Plane (Platanus × acerifolia (Aiton) Willd.) Street Trees in Nanjing City
Authors: Wang Yunhan , Wu Youlv , Sun Qianting , Hu Chunxia , Liu Hao , Chen Chuyu , Xiao Pengfeng
Published: August 2023

The London plane (Platanus × acerifolia (Aiton) Willd.) street tree is a symbolic tree species in Nanjing City, which is known as the “city card”. However, accidents such as street trees falling over cars, affecting traffic, and hurting people have seriously affected the daily lives of citizens. Thus, it is of vital significance to accurately assess the potential for tree failure in London plane street trees in Nanjing City. This study comprehensively considers the growth condition of London plane street trees and their impact on traffic, establishes a scientific street tree failure assessment scheme that contains eight characteristics, creates a tree failure assessment database by thoroughly collecting data on trees, and develops a tree failure assessment model based on factor analysis and k-means clustering. The assessment results show that street trees that pose a high or medium potential for failure are present in proportions of 4.47% and 34.85%, respectively, and are mostly found in Gulou District, Xuanwu District, and Qinhuai District. The average tree failure score of London plane street trees on Changjiang Road in Xuanwu District is the highest, while the road with the lowest tree failure score is Mufu East Road in Gulou District. The results will provide a scientific basis for the maintenance of London plane street trees in Nanjing City and have reference significance for other street tree failure assessment studies.
The Wildfire Dataset: Enhancing Deep Learning-Based Forest Fire Detection with a Diverse Evolving Open-Source Dataset Focused on Data Representativeness and a Novel Multi-Task Learning Approach
Authors: El-Madafri Ismail , Peña Marta , Olmedo-Torre Noelia
Published: August 2023

This study explores the potential of RGB image data for forest fire detection using deep learning models, evaluating their advantages and limitations, and discussing potential integration within a multi-modal data context. The research introduces a uniquely comprehensive wildfire dataset, capturing a broad array of environmental conditions, forest types, geographical regions, and confounding elements, aiming to reduce high false alarm rates in fire detection systems. To ensure integrity, only public domain images were included, and a detailed description of the dataset’s attributes, URL sources, and image resolutions is provided. The study also introduces a novel multi-task learning approach, integrating multi-class confounding elements within the framework. A pioneering strategy in the field of forest fire detection, this method aims to enhance the model’s discriminatory ability and decrease false positives. When tested against the wildfire dataset, the multi-task learning approach demonstrated significantly superior performance in key metrics and lower false alarm rates compared to traditional binary classification methods. This emphasizes the effectiveness of the proposed methodology and the potential to address confounding elements. Recognizing the need for practical solutions, the study stresses the importance of future work to increase the representativeness of training and testing datasets. The evolving and publicly available wildfire dataset is anticipated to inspire innovative solutions, marking a substantial contribution to the field.
SMRT Sequencing Enables High-Throughput Identification of Novel AAVs from Capsid Shuffling and Directed Evolution
Authors: Casy Widler , Garza Irvin , Chen Xin , Dong Thomas , Hu Yuhui , Kanchwala Mohammed , Trygg Cynthia , Shyng Charles , Xing Chao , Bunnell Bruce , Braun Stephen , Gray Steven
Published: August 2023

The use of AAV capsid libraries coupled with various selection strategies has proven to be a remarkable approach for generating novel AAVs with enhanced and desired features. The inability to reliably sequence the complete capsid gene in a high-throughput manner has been the bottleneck of capsid engineering. As a result, many library strategies are confined to localized and modest alterations in the capsid, such as peptide insertions or single variable region (VR) alterations. The caveat of short reads by means of next-generation sequencing (NGS) hinders the diversity of capsid library construction, shifting the field away from whole-capsid modifications. We generated AAV capsid shuffled libraries of naturally occurring AAVs and applied directed evolution in both mice and non-human primates (NHPs), with the goal of yielding AAVs that are compatible across both species for translational applications. We recovered DNA from the tissues of injected animal and used single molecule real-time (SMRT) sequencing to identify variants enriched in the central nervous system (CNS). We provide insights and considerations for variant identification by comparing bulk tissue sequencing to that of isolated nuclei. Our work highlights the potential advantages of whole-capsid engineering, as well as indispensable methodological improvements for the analysis of recovered capsids, including the nuclei-enrichment step and SMRT sequencing.
The Betel Nut Intervention Trial (BENIT)—A Randomized Clinical Trial for Areca Nut and Betel Quid Cessation: Primary Outcomes
Authors: Herzog Thaddeus A. , Wilkens Lynne R. , Badowski Grazyna , Mendez Ana Joy Pacilan , Franke Adrian A. , Pokhrel Pallav , Chennaux Jade S. N. , Tenorio Lynnette F. , Sotto Patrick P. , Kawamoto Crissy T. , Paulino Yvette C.
Published: August 2023

Background: Areca nut and betel quid (ANBQ) chewing is a widespread carcinogenic habit. The BENIT (ClinicalTrials—NCT02942745) is the first known randomized trial designed for ANBQ chewers. Methods: We compared the intensive behavioral treatment intervention condition (IC) with the control condition (CC) in the BENIT and included a 5-stage early stopping rule. We report the primary analysis at stage 3. English-literate adults in Guam and Saipan who self-identified as ANBQ chewers with tobacco were enrolled between August 2016 and August 2020. IC participants (n = 88) received five in-person sessions over 22 days and a brochure containing quitting advice. CC participants (n = 88) received only the brochure. Participants were assessed at baseline and on day 22 of follow-up. Self-reported chewing status at day 22 was determined by a composite of two survey items with disparate wording and response options for cross-verification. Results: Cessation rates were 38.6% (IC) and 9.1% (CC). Proportional hazards regression revealed a p = 0.0058, which met the Stage 3 criteria for significance, and an estimated reduction in ANBQ chewing for IC compared to the CC of 71% (95% CI: 41%–88%). Conclusions: Robust self-reported intervention effects at day 22 suggest that intensive cessation programs such as BENIT should be further developed and implemented on a larger scale.
Insight into the Molecular Mechanism of Diabetic Kidney Disease and the Role of Metformin in Its Pathogenesis
Authors: Kleibert Marcin , Zygmunciak Przemysław , Łakomska Klaudia , Mila Klaudia , Zgliczyński Wojciech , Mrozikiewicz-Rakowska Beata
Published: August 2023

Diabetic kidney disease (DKD) is one of the leading causes of death among patients diagnosed with diabetes mellitus. Despite the growing knowledge about the pathogenesis of DKD, we still do not have effective direct pharmacotherapy. Accurate blood sugar control is essential in slowing down DKD. It seems that metformin has a positive impact on kidneys and this effect is not only mediated by its hypoglycemic action, but also by direct molecular regulation of pathways involved in DKD. The molecular mechanism of DKD is complex and we can distinguish polyol, hexosamine, PKC, and AGE pathways which play key roles in the development and progression of this disease. Each of these pathways is overactivated in a hyperglycemic environment and it seems that most of them may be regulated by metformin. In this article, we summarize the knowledge about DKD pathogenesis and the potential mechanism of the nephroprotective effect of metformin. Additionally, we describe the impact of metformin on glomerular endothelial cells and podocytes, which are harmed in DKD.
Lipid Mediators and Cytokines/Chemokines Display Differential Profiles in Severe versus Mild/Moderate COVID-19 Patients
Authors: Ravindran Resmi , O’Connor Ellen , Gupta Ajay , Luciw Paul A. , Khan Aleena I. , Dorreh Nasrin , Chiang Kate , Ikram Aamer , Reddy Srinivasa
Published: August 2023

Host immune responses play a key role in COVID-19 pathogenesis. The underlying phenomena are orchestrated by signaling molecules such as cytokines/chemokines and lipid mediators. These immune molecules, including anti-SARS-CoV-2 antibodies, interact with immune cells and regulate host responses, contributing to inflammation that drives the disease. We investigated 48 plasma cytokines/chemokines, 21 lipid mediators, and anti-S protein (RBD) antibodies in COVID-19 patients (n = 56) and non-COVID-19 respiratory disease controls (n = 49), to identify immune-biomarker profiles. Cytokines/chemokines (IL-6, CXCL-10 (IP-10), HGF, MIG, MCP-1, and G-CSF) and lipid mediators (TxB2, 11-HETE, 9-HODE, 13-HODE, 5-HETE, 12-HETE, 15-HETE, 14S-HDHA, 17S-HDHA, and 5-oxo ETE) were significantly elevated in COVID-19 patients compared to controls. In patients exhibiting severe disease, pro-inflammatory cytokines/chemokines (IL-6, CXCL-10, and HGF) and anti-SARS-CoV-2 antibodies were significantly elevated. In contrast, lipid mediators involved in the reduction/resolution of inflammation, in particular, 5-HETE, 11-HETE, and 5-oxoETE, were significantly elevated in mild/moderate disease. Taken together, these immune-biomarker profiles provide insight into immune responses related to COVID-19 pathogenesis. Importantly, our findings suggest that elevation in plasma concentrations of IL-6, CXCL-10, HGF, and anti-SARS-CoV-2 antibodies can predict severe disease, whereas elevation in lipid mediators peaks early (compared to cytokines) and includes induction of mechanisms leading to reduction of inflammation, associated complications, and maintenance of homeostasis.
Performance of Reverse Transcription Loop-Mediated Isothermal Amplification (RT-LAMP) Targeting the RNA Polymerase Gene for the Direct Detection of SARS-CoV2 in Nasopharyngeal Swabs
Authors: Hoffmann Elias da Rosa , Balzan Lisiane da Rocha , Inamine Everton , Pancotto Lisiane Rech , Gaboardi Guilherme , Cantarelli Vlademir Vicente
Published: August 2023

In 2020, a global pandemic caused by SARS-CoV-2 was declared. Different institutes proposed diagnostic molecular methods to detect the virus in clinical samples. This study aims to validate and standardize the use of a loop-mediated isothermal amplification (LAMP)-based methodology targeting the viral RP gene, as a faster and low-cost diagnostic method for SARS-CoV-2 infections. The results obtained with RT-LAMP (Reverse Transcriptase) were compared to the results of real-time polymerase chain reaction (RT-PCR) to assess its sensitivity and specificity. In total, 115 samples (nasopharyngeal samples) were used for detecting SARS-CoV-2 by RT-LAMP, with 43 positives and 72 negatives. The study showed a positive predictive value (PPV) of 90.7% and a negative predictive value (VPN) of 100%. The LAMP assay also demonstrated a high sensitivity of 90.7% and a specificity of 100% (confidence interval 77.9–97.4%) when using the lower detection limit of 40 copies/µL. The RT-LAMP described here has the potential to detect even the new variants of SARS-CoV-2, suggesting that it may not be significantly affected by gene mutations. The RT-LAMP targeting the RP viral region is faster and less expensive than other molecular approaches, making it an alternative for developing countries.
The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies
Authors: Chinna Prishanta , Bratl Katrin , Lambarey Humaira , Blumenthal Melissa , Schäfer Georgia
Published: August 2023

The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi’s sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus’ infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses’ biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.
Informing the Cannabis Conjecture: From Life’s Beginnings to Mitochondria, Membranes and the Electrome—A Review
Authors: Nunn Alistair V. W. , Guy Geoffrey W. , Bell Jimmy D.
Published: August 2023

Before the late 1980s, ideas around how the lipophilic phytocannabinoids might be working involved membranes and bioenergetics as these disciplines were “in vogue”. However, as interest in genetics and pharmacology grew, interest in mitochondria (and membranes) waned. The discovery of the cognate receptor for tetrahydrocannabinol (THC) led to the classification of the endocannabinoid system (ECS) and the conjecture that phytocannabinoids might be “working” through this system. However, the how and the “why” they might be beneficial, especially for compounds like CBD, remains unclear. Given the centrality of membranes and mitochondria in complex organisms, and their evolutionary heritage from the beginnings of life, revisiting phytocannabinoid action in this light could be enlightening. For example, life can be described as a self-organising and replicating far from equilibrium dissipating system, which is defined by the movement of charge across a membrane. Hence the building evidence, at least in animals, that THC and CBD modulate mitochondrial function could be highly informative. In this paper, we offer a unique perspective to the question, why and how do compounds like CBD potentially work as medicines in so many different conditions? The answer, we suggest, is that they can modulate membrane fluidity in a number of ways and thus dissipation and engender homeostasis, particularly under stress. To understand this, we need to embrace origins of life theories, the role of mitochondria in plants and explanations of disease and ageing from an adaptive thermodynamic perspective, as well as quantum mechanics.
Blastomycosis-Associated Hospitalizations, United States, 2010–2020
Authors: Benedict Kaitlin , Hennessee Ian , Gold Jeremy A. W. , Smith Dallas J. , Williams Samantha , Toda Mitsuru
Published: August 2023

Background: Blastomycosis is an environmentally acquired fungal disease that can cause severe illness, with approximately 65% of reported cases requiring hospitalization. Recent trends in blastomycosis-associated hospitalizations in the United States have not been described. Methods: We analyzed hospital discharge data from the Healthcare Cost and Utilization Project (HCUP) National (Nationwide) Inpatient Sample. We calculated hospitalization rates per 100,000 population using U.S. census data and examined factors associated with in-hospital mortality. Results: An estimated 11,776 blastomycosis-associated hospitalizations occurred during 2010–2020 (average yearly rate 0.3 per 100,000 persons), with no apparent temporal trend. Rates were consistently highest among persons ≥65 years old and males. In-hospital death occurred in 7.9% and approximately doubled from 3.9% in 2010 to 8.5% in 2020. Older age, chronic obstructive pulmonary disease, and malignancy were associated with mortality. Conclusions: Blastomycosis-associated hospitalizations can result in poor outcomes, underscoring the continued need for attention to early detection and treatment of blastomycosis and monitoring of disease trends.
Recent Progress of Layered Double Hydroxide-Based Materials in Wastewater Treatment
Authors: Fu Yanli , Fu Xiaoqian , Song Wen , Li Yanfei , Li Xuguang , Yan Liangguo
Published: August 2023

Layered double hydroxides (LDHs) can be used as catalysts and adsorbents due to their high stability, safety, and reusability. The preparation of modified LDHs mainly includes coprecipitation, hydrothermal, ion exchange, calcination recovery, and sol–gel methods. LDH-based materials have high anion exchange capacity, good thermal stability, and a large specific surface area, which can effectively adsorb and remove heavy metal ions, inorganic anions, organic pollutants, and oil pollutants from wastewater. Additionally, they are heterogeneous catalysts and have excellent catalytic effect in the Fenton system, persulfate-based advanced oxidation processes, and electrocatalytic system. This review ends with a discussion of the challenges and future trends of the application of LDHs in wastewater treatment.
Skin Friction: Mechanical and Tribological Characterization of Different Papers Used in Everyday Life
Authors: Vilhena Luís , Afonso Luís , Ramalho Amílcar
Published: August 2023

The coefficient of friction for different contacting materials against skin is mainly influenced by the nature of the materials (synthetic and natural fabrics), mechanical contact parameters (interfacial pressure and sliding velocities), and physiological skin conditions (ambient humidity and skin moisture content). In the present research work, seven different types of papers used in everyday life were analyzed. The physical properties of these materials were determined through tensile tests and friction tests. By comparing mechanical properties with coefficient of friction, it was possible to conclude that the coefficient of friction is strongly correlated with the mechanical properties.
Modification and Enhancing Contribution of Fiber to Asphalt Binders and Their Corresponding Mixtures: A Study of Viscoelastic Properties
Authors: Li Chao , Liu Hao , Xiao Yue , Li Jixin , Wang Tianlei , Peng Longfan
Published: August 2023

The performance of asphalt binders and asphalt mixtures can be enhanced by the inclusion of fiber. The viscoelastic characteristics of fiber-reinforced asphalt binders and their corresponding mixtures were characterized in this study. To generate fiber-reinforced asphalt samples for dynamic shear rheometer (DSR) tests, polypropylene fibers (PPFs), polyester fibers (PFs), and lignin fibers (LFs) were added into modified asphalt with a ratio of 5wt%. Indirect tensile resilience tests were conducted on the fiber-reinforced asphalt mixture with Marshall samples, which was prepared with a 6.4% of bitumen/aggregate ratio. The addition of fiber can increase the anti-rutting performance of asphalt binders, and also reduce the anti-fatigue performance of asphalt binders to varying degrees. Viscoelastic properties of the fiber-reinforced asphalt binders are highly dependent on the shape of the used fiber. The resistance of the fiber-reinforced asphalt binders to rutting at high temperatures increases with the roughness degree of the fiber’s surface morphology. PPF-reinforced asphalt binders surpass the others in terms of anti-rutting capabilities. The high-temperature deformation resistance of the PPF-reinforced asphalt mixture is stronger, whereas the low-temperature crack resistance of the PF-reinforced asphalt mixture is stronger, which can be observed from the master curve of indirect tensile resilient modulus.
Identification of the Natural Frequencies of Oscillations of Perforated Vibrosurfaces with Holes of Complex Geometry
Authors: Kharchenko Serhii , Samborski Sylwester , Kharchenko Farida , Mitura Andrzej , Paśnik Jakub , Korzec Izabela
Published: August 2023

The reliability of perforated vibrosurfaces is one of the main parameters of the efficiency of their operation in many technological processes. Existing methods for studying vibrosurfaces with standard single holes and the corresponding results cannot be used to study the reliability of vibration surfaces with holes of complex geometric shapes. The proposed method is based on the experimental modal identification of the parameters of natural oscillations, the parallel creation of a numerical model using the finite element method, and the comparison of the results. Three vibrosurfaces were investigated: solid without holes, perforated with standard round holes, perforated with holes in the form of a five-petal epicycloid. As a result of experiments, the divergence of natural vibrations of perforated surfaces depending on the side of the punch and matrix during their technological production by pressing was established. The result of the research was a refined adequate numerical model that takes into account the presence of holes in complex geometric shapes. A methodology has been developed, and analytical expressions with perforation coefficients have been obtained, which allow obtaining values of natural oscillations of vibration surfaces depending on the properties of metal, boundary conditions, and structural and kinematic parameters.
Analysis of Durability of Watertight Concretes Modified with the Addition of Fly Ash
Authors: Adamus Janina , Langier Bogdan
Published: August 2023

The growing demand for watertight concrete structures is conducive to the development of research in this area, but their results are rarely published. In order to partially fill this gap, the authors of the publication present the results of research into the effect of fly ash addition on the watertightness of concrete. Prior to the tests, a recipe for a concrete mix with the addition of a sealing admixture modified with fly ash was developed. The following properties were analyzed: consistency of the concrete mix, air content in the concrete mix, compressive strength of concrete, depth of penetration of water under pressure, and frost resistance of concrete for F150 level. The work meets the expectations of the construction industry with respect to the production of concrete structures resistant not only to the penetration of water into concrete but also resistant to aggressive substances dissolved in water that accelerate the destruction of concrete and corrosion of reinforcement bars. Based on the test results, it was found that the addition of fly ash to the concrete mix enhances the positive impact of the applied sealing admixture, increasing the tightness of the concrete. It reduces the depth of penetration of water under pressure and therefore increases the frost resistance of concrete.
Reviewing the Integrated Design Approach for Augmenting Strength and Toughness at Macro- and Micro-Scale in High-Performance Advanced Composites
Authors: Sadeghi Behzad , Cavaliere Pasquale Daniele
Published: August 2023

In response to the growing demand for high-strength and high-toughness materials in industries such as aerospace and automotive, there is a need for metal matrix composites (MMCs) that can simultaneously increase strength and toughness. The mechanical properties of MMCs depend not only on the content of reinforcing elements, but also on the architecture of the composite (shape, size, and spatial distribution). This paper focuses on the design configurations of MMCs, which include both the configurations resulting from the reinforcements and the inherent heterogeneity of the matrix itself. Such high-performance MMCs exhibit excellent mechanical properties, such as high strength, plasticity, and fracture toughness. These properties, which are not present in conventional homogeneous materials, are mainly due to the synergistic effects resulting from the interactions between the internal components, including stress–strain gradients, geometrically necessary dislocations, and unique interfacial behavior. Among them, aluminum matrix composites (AMCs) are of particular importance due to their potential for weight reduction and performance enhancement in aerospace, electronics, and electric vehicles. However, the challenge lies in the inverse relationship between strength and toughness, which hinders the widespread use and large-scale development of MMCs. Composite material design plays a critical role in simultaneously improving strength and toughness. This review examines the advantages of toughness, toughness mechanisms, toughness distribution properties, and structural parameters in the development of composite structures. The development of synthetic composites with homogeneous structural designs inspired by biological composites such as bone offers insights into achieving exceptional strength and toughness in lightweight structures. In addition, understanding fracture behavior and toughness mechanisms in heterogeneous nanostructures is critical to advancing the field of metal matrix composites. The future development direction of architectural composites and the design of the reinforcement and toughness of metal matrix composites based on energy dissipation theory are also proposed. In conclusion, the design of composite architectures holds enormous potential for the development of composites with excellent strength and toughness to meet the requirements of lightweight structures in various industries.
Milling Mechanism and Chattering Stability of Nickel-Based Superalloy Inconel 718
Authors: Zheng Jin , Zhang Yaoman , Qiao Hanying
Published: August 2023

Nickel-based superalloy Inconel 718 is widely used in the aerospace industry for its excellent high-temperature strength and thermal stability. However, milling Inconel 718 presents challenges because of the significantly increased cutting force and vibration, since Inconel 718 is a typical difficult-to-machine material. This paper takes the milling process of Inconel 718 as the research object, initially, and a milling force model of Inconel 718 is established. Subsequently, the finite element analysis method is used to analyze the stress field, temperature field, and milling force in the milling process of Inconel 718. Building upon this, a dynamic equation of the milling of Inconel 718 is established, and based on the modal experiment, stability lobe diagrams are drawn. Furthermore, milling experiments on Inconel 718 are designed, and the results calculated using the milling force model and finite element analysis are verified through comparison to the experimental results; then, the fmincon optimization algorithm is used to optimize the processing parameters of Inconel 718. Eventually, the results of the multi-objective optimization illustrate that the best processing parameters are a spindle speed of 3199.2 rpm and a feed speed of 80 mm/min with an axial depth of cut of 0.25 mm. Based on this, the best machining parameters are determined, which point towards an improvement of the machining efficiency and quality of Inconel 718.
Study of The Gas-Swelling Mechanisms in Silicon Carbide Ceramics under High-Temperature Irradiation with Helium Ions
Authors: Tynyshbayeva Kymbat M. , Kozlovskiy Artem L. , Rakhimov Ruslan V. , Uglov Vladimir V. , Zdorovets Maxim V.
Published: August 2023

The purpose of this work is to simulate the processes of gaseous swelling in SiC ceramics as well as the associated changes in strength and thermophysical properties under high-temperature irradiation with helium ions. The choices of irradiation conditions (irradiation temperatures of 700 and 1000 K) and irradiation fluences (1015–1018 ion/cm2) are based on the possibilities of modeling the processes of destructive changes in the near-surface layer as a result of the accumulation of gas-filled inclusions during high-dose irradiation. During this study, it was found that an increase in the irradiation temperature of the samples from 700 to 1000 K leads to a decrease in the resistance to gas swelling, since with the temperature increase, the mobility of implanted helium in the near-surface layer grows, which results in an increase in the size of gas-filled bubbles and, as a result, accelerated destruction of the damaged layer. It has been established that in the case of irradiation at 700 K, the critical fluence for swelling associated with the formation of visible gas-filled bubbles on the surface is 5 × 1017 ion/cm2, while for samples irradiated at a temperature of 1000 K, the formation of gas-filled bubbles is observed at a fluence of 1017 ion/cm2. Measurements of the thermal conductivity coefficient showed that the formation of gas-filled bubbles leads to a sharp deterioration in heat transfer processes, which indicates that the created defective inclusions prevent phonon heat transfer. Changes in the strength characteristics showed that a decrease in hardness occurs throughout the entire depth of the damaged ceramic layer. However, with a rise in the irradiation fluence above 1017 ion/cm2, a slight damaged layer thickness growth associated with diffusion processes of helium implantation into the near-surface layer is observed. The relevance of this study consists in obtaining new data on the stability of the strength and thermophysical parameters of SiC ceramics in the case of helium accumulation and its subsequent radiation-induced evolution in the case of irradiation at temperatures of 700 and 1000 K. The data obtained during the experimental work on changes in the properties of ceramics will make it possible to determine the potential limits of their applicability in the case of operation under extreme conditions at elevated temperatures in the future.
Nanoflake NiMn Layered Double Hydroxide Coated on Porous Membrane-like Ni-Foam for Sustainable and Efficient Electrocatalytic Oxygen Evolution
Authors: Magotra Verjesh Kumar , Magotra Arjun , Mali Sawanta S. , Jeon Hee C. , Kang Tae W. , Salunke Amol S. , Hong Chang Kook , Shrestha Nabeen K. , Im Hyunsik , Inamdar Akbar I.
Published: August 2023

Layered double hydroxides (LDHs) have gained vast importance as an electrocatalyst for water electrolysis to produce carbon-neutral and clean hydrogen energy. In this work, we demonstrated the fabrication of nano-flake-like NiMn LDH thin film electrodes onto porous membrane-like Ni-foam by using a simple and cost-effective electrodeposition method for oxygen evolution reaction (OER). Various Ni1-xMnx LDH (where x = 0.15, 0.25, 0.35, 0.50 and 0.75) thin film electrodes are utilized to achieve the optimal catalyst for an efficient and sustainable OER process. The various composition-dependent surface morphologies and porous-membrane-like structure provided the high electrochemical surface area along with abundant active sites facilitating the OER. The optimized catalyst referred to as Ni0.65Mn0.35 showed excellent OER properties with an ultralow overpotential of 253 mV at a current density of 50 mAcm−2, which outperforms other state-of-the art catalysts reported in the literature. The relatively low Tafel slope of 130 mV dec−1 indicates faster and more favorable reaction kinetics for OER. Moreover, Ni0.65Mn0.35 exhibits excellent durability over continuous operation of 20 h, indicating the great sustainability of the catalyst in an alkaline medium. This study provides knowledge for the fabrication and optimization of the OER catalyst electrode for water electrolysis.
Microfluidic Microcirculation Mimetic for Exploring Biophysical Mechanisms of Chemotherapy-Induced Metastasis
Authors: Abraham Ashley , Virdi Sukhman , Herrero Nick , Bryant Israel , Nwakama Chisom , Jacob Megha , Khaparde Gargee , Jordan Destiny , McCuddin Mackenzie , McKinley Spencer , Taylor Adam , Peeples Conner , Ekpenyong Andrew
Published: August 2023

There is rapidly emerging evidence from pre-clinical studies, patient samples and patient subpopulations that certain chemotherapeutics inadvertently produce prometastatic effects. Prior to this, we showed that doxorubicin and daunorubicin stiffen cells before causing cell death, predisposing the cells to clogging and extravasation, the latter being a step in metastasis. Here, we investigate which other anti-cancer drugs might have similar prometastatic effects by altering the biophysical properties of cells. We treated myelogenous (K562) leukemic cancer cells with the drugs nocodazole and hydroxyurea and then measured their mechanical properties using a microfluidic microcirculation mimetic (MMM) device, which mimics aspects of blood circulation and enables the measurement of cell mechanical properties via transit times through the device. We also quantified the morphological properties of cells to explore biophysical mechanisms underlying the MMM results. Results from MMM measurements show that nocodazole- and hydroxyurea-treated K562 cells exhibit significantly altered transit times. Nocodazole caused a significant (p < 0.01) increase in transit times, implying a stiffening of cells. This work shows the feasibility of using an MMM to explore possible biophysical mechanisms that might contribute to chemotherapy-induced metastasis. Our work also suggests cell mechanics as a therapeutic target for much needed antimetastatic strategies in general.
Stability Analysis of Cemented Tailings Backfill in Stope Considering Layered Structural Characteristics
Authors: Wang Jie , Yu Qingjun , Wang Guannan , Tong Dazhi
Published: August 2023

In this study, the stage subsequent to filling mining is selected as the background, and the cemented tailings backfill serves as the research object. Given the effects of the layer effect, top load, lateral pressure coefficient, and so forth, a safety factor calculation model of cemented tailings backfill in large depth–width ratio stopes is developed in accordance with the Mohr–Coulomb failure criterion, which is compared with the models proposed by other scholars. Lastly, the characteristics of the effect exerted by a wide variety of factors are discussed. As indicated by the results, (1) there are three scenarios in the position of the sliding surface, located in the first layer, passing through two layers and passing through three layers, and mainly the first two. Compared with other models, the rationality and reliability of the model in this study are verified. Different models have different research backgrounds and different focuses, and certain differences exist in results. (2) The safety factor of cemented tailings backfills is reduced with the increase of the top load, the lateral pressure coefficient, and the bulk density, while it is increased with the increase of cohesion, internal friction angle, and bonding force ratio. Furthermore, a linear functional relationship exists between them. The safety factor has the maximum sensitivity to cohesion and the minimum sensitivity to top load. (3) Using Statistical Package for the Social Sciences (SPSS) software for regression analysis, a simplified multiple linear regression equation between the safety factor and the respective factor is built. The regression results achieve an error of 10%. As revealed by the result of this study, the simplified regression equation can be applied to the stability evaluation of the on-site cemented tailings backfill.
Emerging Developments in Separation Techniques and Analysis of Chiral Pharmaceuticals
Authors: Al-Sulaimi Sulaiman , Kushwah Reveka , Abdullah Alsibani Mohammed , El Jery Atef , Aldrdery Moutaz , Ashraf Ghulam Abbas
Published: August 2023

Chiral separation, the process of isolating enantiomers from a racemic mixture, holds paramount importance in diverse scientific disciplines. Using chiral separation methods like chromatography and electrophoresis, enantiomers can be isolated and characterized. This study emphasizes the significance of chiral separation in drug development, quality control, environmental analysis, and chemical synthesis, facilitating improved therapeutic outcomes, regulatory compliance, and enhanced industrial processes. Capillary electrophoresis (CE) has emerged as a powerful technique for the analysis of chiral drugs. This review also highlights the significance of CE in chiral drug analysis, emphasizing its high separation efficiency, rapid analysis times, and compatibility with other detection techniques. High-performance liquid chromatography (HPLC) has become a vital technique for chiral drugs analysis. Through the utilization of a chiral stationary phase, HPLC separates enantiomers based on their differential interactions, allowing for the quantification of individual enantiomeric concentrations. This study also emphasizes the significance of HPLC in chiral drug analysis, highlighting its excellent resolution, sensitivity, and applicability. The resolution and enantiomeric analysis of nonsteroidal anti-inflammatory drugs (NSAIDs) hold great importance due to their chiral nature and potential variations in pharmacological effects. Several studies have emphasized the significance of resolving and analyzing the enantiomers of NSAIDs. Enantiomeric analysis provides critical insights into the pharmacokinetics, pharmacodynamics, and potential interactions of NSAIDs, aiding in drug design, optimization, and personalized medicine for improved therapeutic outcomes and patient safety. Microfluidics systems have revolutionized chiral separation, offering miniaturization, precise fluid control, and high throughput. Integration of microscale channels and techniques provides a promising platform for on-chip chiral analysis in pharmaceuticals and analytical chemistry. Their applications in techniques such as high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) offer improved resolution and faster analysis times, making them valuable tools for enantiomeric analysis in pharmaceutical, environmental, and biomedical research.
Momordica charantia-Derived Extracellular Vesicles Provide Antioxidant Protection in Ulcerative Colitis
Authors: Wang Feng , Yuan Meng , Shao Chenqi , Ji Nan , Zhang Haifeng , Li Chunmei
Published: August 2023

Plant-derived extracellular vesicles are functional nanovesicles that have significant applications in both disease prevention and treatment, as well as for use as drug carriers. Momordica charantia is a widely consumed food that has both medicinal and nutritional properties and has shown intervention in diabetes and inflammation caused by oxidative damage. In this study, Momordica charantia-derived extracellular vesicles (MCEVs) were extracted and demonstrated to have excellent antioxidant activity by characterization, lipid composition analysis, protein domain analysis, and in vitro antioxidant measurement. In addition, in vivo studies indicated that the MCEVs could restore ulcerative colitis by regulating oxidation and inflammatory factors. Therefore, the antioxidant properties of MCEVs may be important in protecting the colon from inflammation, which provides new insights into the application of MCEVs as drugs or vectors for intervention in ulcerative colitis.
Recent Progresses in the Catalytic Stereoselective Dearomatization of Pyridines
Authors: Comparini Lucrezia Margherita , Pineschi Mauro
Published: August 2023

1,2- and 1,4-dihydropyridines and N-substituted 2-pyridones are very important structural motifs due to their synthetic versatility and vast presence in a variety of alkaloids and bioactive molecules. In this article, we gather and summarize the catalytic and stereoselective synthesis of partially hydrogenated pyridines and pyridones via the dearomative reactions of pyridine derivatives up to mid-2023. The material is fundamentally organized according to the type of reactivity (electrophilic/nucleophilic) of the pyridine nucleus. The material is further sub-divided taking into account the nucleophilic species when dealing with electrophilic pyridines and considering the reactivity manifold of pyridine derivatives behaving as nucleophiles at the nitrogen site. The latter more recent approach allows for an unconventional entry to chiral N-substituted 2- and 4-pyridones in non-racemic form.