bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Evaluation of Antimicrobial Efficacy of Simvastatin Paste and Aloe Vera Paste as a Pulpotomy MedicamentAn In-vitro Study
Authors: Kabra Sakshi Pravin , Thosar Nilima
Published: March 2023

Introduction: Pulpotomy is the complete removal of the coronal part of the dental pulp, followed by the application of an appropriate dressing or medicament to promote healing and maintain the viability of the teeth in the dental arch. Aloe vera has anti-inflammatory, anti-bacterial properties which can be used as a pulpotomy medicament. Simvastatin, a lipid-lowering medication has recently emerged as a potential medicament in regenerative dentistry. It has an anti-inflammatory and anti-oxidant properties. Hence, it can be used as a pulpotomy medicament. Aim: To evaluate and compare the antimicrobial efficacy of Aloe Vera paste and Simvastatin paste as pulpotomy medicament against Pseudomonas aeruginosa and E. faecalis. Materials and Methods: An in-vitro study will be conducted in Department of Paediatric and Preventive Dentistry at Sharad Pawar Dental College, Wardha, Maharashtra, India, in which Aloe Vera paste and Simvastatin paste will be prepared in an aseptic environment. The antimicrobial activity of simvastatin paste and Aloe Vera paste against E.faecalis and pseudomonas will be assessed using the agar diffusion method. It will be cultured overnight in brain heart infusion broth. On blood agar media, pseudomonas aeruginosa will be inoculated. 4 mm wells will be punched out on plates with a puncher and will be instantly loaded with freshly customised test materials. The agar plates shall then be incubated in an incubator at 37°C for 24 hours and 72 hours before being analysed. Statistical analysis will be done using Chi-square test, ANOVA test and multiple comparision 2k test. Expected Results: Aloe Vera and Simvastatin in the paste form shall be able to show its antimicrobial efficacy as a pulpotomy medicament. Conclusion: Aloe Vera paste and Simvastatin paste shall provide antimicrobial efficacy against E. faecalis and pseudomonas and prove to be a better pulpotomy medicament for primary teeth.
Association of Radiological Features with Histological Features in Patients with Renal Cell Carcinoma: A Cross-sectional Study
Authors: Garg Atul , Barua Sasanka Kumar , Rajeev TP , Sarma Debanga , Trivedi Sameer , Singh Yashasvi , Baruah Saumar Jyoti , Agrawal Lalit Kumar
Published: March 2023

Introduction: Renal Cell Carcinoma (RCC) is a group of neoplastic lesions with unique cytogenetic characteristics and histopathological features. The majority of studies till date on RCC have been focusing on tissue histology to plan neoadjuvant treatment in clinical settings. An accurate forecast of the histopathological subtype has clinical implications in management and response to newer treatment strategies. It is pertinent to preoperatively distinguish a solid renal masses histologically but, there are currently no well-established imaging criteria to classify these tumors on the basis of radiographic evaluation. Aim: To evaluate the differences in imaging characteristics of different histological subtypes of RCC by Power Doppler Ultrasound and Multi-Detector Computed Tomography (MDCT) scan. Materials and Methods: This cross-sectional study was conducted in the Department of Urology, Gauhati Medical College and Hospital, Guwahati, Assam, from March 2016 to December 2017. The study population consisted of 61 patients of RCC who were evaluated with MDCT and Doppler ultrasound prior to surgery and findings were correlated with histopathological forms of tumour. The Pearson Chi-square test and ANOVA test was used to statistically analyse the data. Results: Histopathology revealed clear cell Renal Cell Carcinoma (ccRCC), chromophobe Renal Cell Carcinoma (chRCC) and papillary Renal Cell Carcinoma (pRCC) in 52, 4 and 5 patients, respectively. Heterogenous enhancement was found in 51 cases and among these 90.4% were ccRCC. Absolute attenuation values in Corticomedullary Phase (CMP) and Nephrographic Phase (NP) for clear cell and chromophobe subtype were higher than papillary subtype, i.e., 88.04±30.40 Hounsfield Unit (HU) and 72.41±20.17 HU for clear cell, 60.75±22.54 HU and 88±16.06 HU for chromophobe; 22.40±12.52 HU and 58.00±4.41 HU for papillary subtype, respectively. Papillary RCC (pRCC) showed a unique enhancement pattern, with a low peak enhancement (average peak of 55.40 HU) and greatest enhancement during the NP. In this study population ccRCC, ChRCC RCC and pRCC had mean Resistive Index (RI) of 0.63±0.06, 0.58±0.0 and 0.67±0.11, respectively. Conclusion: Power doppler flow imaging is not useful in discriminating subtypes of RCC while multiphasic Computed Tomography (CT) imaging may be useful, particularly the phasic enhancement pattern to distinguish common RCC subtypes which may facilitate treatment planning and choosing appropriate tyrosine kinase inhibitors.
Correlation of Chest CT Scan Severity Score and Disability in Post-COVID-19 Patients: A Cross-sectional Study
Authors: Ghuleliya Rambeer , Asthana Satyasheel Singh , Akhter Minhaj , Kedia Sharad Kumar , Chinchu K , Mathew Merrin Meria , Morvadiya Dhaval , Gonnade Nitesh Manohar
Published: March 2023

Introduction: After recovering from Coronavirus Disease 2019 (COVID-19) patients face various problems like cognitive difficulties, mobility, and self-care. COVID-19 affects the respiratory system at varying severity. The severity of the lung infection was assessed by Chest Computed Tomography (CT) Severity Score (CTSS)- higher the score higher the severity of the disease. Aim: To identify if the CTSS that is done during active disease has any correlation with post-COVID-19 illness disabilities and fatigue. Materials and Methods: A cross-sectional study was conducted in the post-COVID-19 rehabilitation clinic of the Department of Physical Medicine and Rehabilitation, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India. Total of 36, post-COVID-19 patients were included from December 2020 to June 2021. Fatigueness was assessed on Fatigue Severity Score (FSS) and disability was assessed on World Health Organisation Disability Assessment Scale 2.0 (WHODAS 2.0). CTSS was recorded from the patient’s non contrast Chest CT scan report. This CT scan of chest scan was done during active COVID-19 disease. Spearman rank-order Correlation Coefficient (SCC) was used to identify correlations. Results: There was no positive correlation of CTSS (10.3±6.4) with disability (11.3±11.8, p-value- 0.424) and fatigue (3.3±1.8, p-value0.225). There was no correlation found between post-COVID-19 disabilities (11.3±11.8) and fatigue (3.3±1.8, p-value- 0.993). Conclusion: There was no positive correlation found between lung infection severity and disabilities, fatigue after COVID-19.
Release Behaviour of Phosphorus and Its Fractions in Different Phosphorus Status Soils
Authors: Fogat Sunitha , Kumar Rohtas , Dhankar Amit , Jyoti  , Kavita
Published: March 2023

Phosphorus is essential to all forms of life and its contribution towards aiding the native soil fertility and sustaining it, is well known. With passage of time, P added to soil undergoes transformation into various unavailable forms. Native P compounds, some being highly insoluble are mostly unavailable for plant uptake. The availability of phosphorus to the plants depends on soil properties, soil pH, soluble iron, aluminum and manganese, calcium minerals, organic matter, activities of microorganisms thus availability of P may vary according to soil types. Knowing the changes in P fractions especially in low and in high P status soils is much more important for P availability to plant. Therefore, the release behaviour of phosphorus and its fraction in different P status soils was assessed over 5 weeks under laboratory incubation periods using a sequential fractionation procedure. The results of the experiment revealed that the content of available P and different P fractions were higher in high P status soil as compared to low P status soil. Among the various P fractions, Ca-P was the dominant fraction in both soils. The release of available P was first increased up to 21 and 28 days in low and high P status soil, respectively and the release of different forms of P fractions in both soils increased up to 28 days after incubation and then decreased with further increase in incubation period.
Membrane Technology
Authors: Ray Samit Kumar
Published: March 2023

Separation by membranes in chemical and allied industries has been of prime importance in the last few decades because of its low energy requirement and environment friendly process. In the last two decades, there has been significant development of this novel separation technology in academic research and industrial applications. Several new membranes such as new kinds of thin film composite membranes, nanocomposite membranes, metal–organic framework membranes, mixed matrix membranes, polyelectrolyte membranes, graphene and carbon nanotube‐based membranes, polymer inclusion membranes, and new kinds of liquid membranes have been developed for applications in reverse osmosis, nanofiltration, ultrafiltration, microfiltration, pervaporation, gas separation or facilitated transport with liquid membranes. Membranes based on functional polymers and composites of polymer and ceramic materials have shown significant improvement in flux, selectivity, or salt rejection. This article discusses elaborately on the basic principles of membrane separation, types of membranes/modules, synthesis, and characterization of new membrane materials with citation of recent works on this novel separation process.
Hyper‐inflammation and complement in COVID‐19
Authors: Pires Bruno G. , Calado Rodrigo T.
Published: March 2023

COVID‐19 is a complex disease manifesting in a broad severity spectrum and involving distinct organs and systems. Hyperinflammation, including complement over‐activation, has a pivotal role in severe COVID‐19 pathobiology, stimulating the inflammatory response, causing microangiopathy, platelet–neutrophil activation, and hypercoagulability. SARS‐CoV‐2 can directly activate the complement system by the classic, alternative, and lectin pathways, and infected cells can produce intracellular complement (the complesome). COVID‐19 severity appears to be associated with the degree of complement activation, and it has been hypothesized that patients with COVID‐19 may benefit from therapeutic complement inhibition. Different complement cascade molecules may be targeted with potential advantages and disadvantages. Which target(s) is the most effective and when is the best timing for intervention remain open questions. Early phase I and phase II clinical trials have shown promising but conflicting results, warranting phase III controlled randomized trials. Upstream complement inhibition appears to better and more effectively block hyperinflammation with potential clinical significance. Understanding how SARS‐CoV‐2 exploits the complement system can add precious information about the pathogenesis of other infections, inflammatory, and autoimmune diseases beyond COVID‐19.
A review of Bayesian dynamic forecasting models: Applications in marketing
Authors: Migon Helio S. , Alves Mariane Branco , Menezes André F. B. , Pinheiro Eduardo G.
Published: March 2023

We briefly review the main developments of Bayesian dynamic models. The emphasis is on marketing applications. Typical examples in this area are discussed. The concepts of monitoring and intervention are carefully explained with illustrative examples and open source computational routines. We avoid algebraic developments and instead use graphical examples to illustrate theoretical aspects. Two real‐world problems using Bayesian dynamic models are discussed. Finally, we describe recent developments and alternative proposals to formally address the dependence when dealing with the modeling of multiple time series.
A morphine reward generalization mouse model based on conditioned place preference and aversion
Authors: Hou Xue‐Fei , Zhao Ya‐Bo , Yang Yue‐Xiong , Zhu Jing , Zhu Li‐Su , Xu Lin , Zhou Qi‐Xin
Published: March 2023

Background

Conditioned place preference (CPP) is a common behavioral paradigm for studying the association of unconditioned stimulus reward memory with context. Generalization is a flexible memory recall pattern developed on the basis of original memory. Drug‐seeking behaviors in substance use disorders (SUDs) exhibit diversity, which we generally attribute to the highly generalized features of SUD memory. However, to date, there are no animal models for SUD generalization studies.

Methods

We design the generalization box (G‐box) and the generalization retrieval process based on the conditioned place preference (CPP) model. In the memory retrieval stage, we replaced the conditioning CPP box (T‐box) with a generalization box (G‐box) to study drug generalization memory. For appearance, the generalized boxes have different angles and numbers of sides compared to the conditioning boxes. For the visual cues, the shapes of the symbols are different (triangle icons for the hexagonal chamber and dot icons for the round chamber), but the orientation information remains the same. To establish CPP generalization, the mice received morphine on the vertical or horizontal side of a conditioning box (T‐box) and saline on the other side. Then, after CPP conditioning, the generalization test was performed in a generalization box (G‐box: hexagonal chamber and Gr‐box: round chamber) 21 days later.

Results

CPP‐conditioned mice still displayed a clear preference for similar visual information in the G‐box. CPA‐conditioned mice behaved similarly to CPP, with mice consistently avoiding similar visual information in the G‐box. We further observed that the generalization results are similar using two generalization boxes (G‐box and Gr‐box).

Conclusion

In this study, we succeeded in creating a simple and effective generalization model for morphine reward. The establishment of this model provides a new tool for generalization studies of SUD and therapy in humans.
Adapting Strauss and Corbin's grounded theory in clinical case study research in the field of counselling
Authors: Fleet Doreen , Reeves Andrew
Published: March 2023

Case study can be adopted when aiming to understand an individual's lived experience. Such experience produces rich and complex qualitative data for analysis, conducive to counselling and psychotherapy research. Furthermore, grounded theory (GT) can be adopted to produce a theory from qualitative data, fitting well with case study research that explores complex experiences regarding social, psychological and phenomenological processes. This paper aims to guide the counselling researcher to incorporate Strauss and Corbin's model into the main arena of qualitative counselling research. In addition, this paper draws on a multiple case study that adopted Strauss and Corbin's method and identified various phases in the GT process. The aim is to inform the reader how to put the iterative process and pragmatic theoretical sampling into practice to produce a robust theory from clinical case study data.
Use of surgical lasers in small animal dermatology
Authors: Pieper Jason
Published: March 2023

Background:Use of lasers in veterinary medicine has significantly increased over the past decade. What was once a piece of equipment, almost exclusively used by veterinary specialists, has now become a common piece of equipment in general veterinary practices. It is imperative to know the appropriate situations and diseases for which lasers can be used.

Aim of the article:This article covers the basics of lasers, including discussion of both diode and CO2lasers. It also discusses several skin diseases and/or conditions in which lasers are commonly used.
Biologically inspired 3Fe4S cluster as structural mimics of FeMoco M‐cluster
Authors: Lai Ting Yi , Chen Chang‐Ting , Chu Kai‐Ti , Chien Su‐Ying , Ong Tiow‐Gan , Chiang Ming‐Hsi
Published: March 2023

A 3Fe4S cluster related to M‐cluster of Mo‐nitrogenase is reported. [K(THF)5][Fe3(μ‐bdt)2(μ‐PPh2)(CO)5] (1) is synthesized from photo‐assisted structural rearrangement of [K(THF)2][(μ,κ2‐bdt)Fe2(μ‐PPh2)(CO)5] under visible light irradiation. The molecular structure of 1 consists of a Fe3 core bearing one dithiolate bridge and the second dithiolate group capping onto the metallic plane. The structural motif of 1 is analogous to that of Mo‐participated 3Fe4S unit in M‐cluster of Mo‐nitrogenase, with the similar Fe‐Fe and Fe‐S bond distances. Upon protonation in 193 K, a Fe‐hydride species (1H) is generated and characterized to possess the bridging hydride group (δ = −12.57 ppm) by 1H‐NMR spectroscopy and DFT calculation. In CH3CN solution, complex 1 exhibits a reversible reduction and oxidation process at = −1.94 V and = −0.18 V, respectively, at 273 K. The reduction behavior of 1 in CH2Cl2 solution at 243 K displays a slight modification in the presence of trifluoroacetic acid, revealing a moderate anodic potential shift (~50 mV). The current amplitude of the reduction wave is linearly increased with the increasement of acid added, indicative of the catalytic event.
Do job crafting opportunities help to win talent? Disentangling and contextualizing the effects of job crafting opportunities on applicant attraction
Authors: Schüler Jens , Franzke Sonja , Boehnlein Philipp , Baum Matthias
Published: March 2023

We argue that job crafting opportunities are not only helpful to motivate and enable the existing workforce but that they can also function as a signal to attract talent. With the help of two empirical studies (Study 1 – a conjoint experiment and Study 2 – a vignette study), we show that (a) a signaled opportunity for job crafting helps to attract job seekers; (b) job crafting signals can trigger positive as well as negative expectations of central job demands and resources that inform job acceptance intentions, and; (c) a proactive personality strengthens most of the positive expectations of job crafting signals while buffering adverse effects.
Personalized antiseizure medication therapy in critically ill adult patients
Authors: Almohaish Sulaiman , Cook Aaron M. , Brophy Gretchen M. , Rhoney Denise H.
Published: March 2023

Precision medicine has the potential to have a significant impact on both drug development and patient care. It is crucial to not only provide prompt effective antiseizure treatment for critically ill patients after seizures start but also have a proactive mindset and concentrate on epileptogenesis and the underlying cause of the seizures or seizure disorders. Critical illness presents different treatment issues compared with the ambulatory population, which makes it challenging to choose the best antiseizure medications and to administer them at the right time and at the right dose. Since there is a paucity of information available on antiseizure medication dosing in critically ill patients, therapeutic drug monitoring is a useful tool for defining each patient's personal therapeutic range and assisting clinicians in decision‐making. Use of pharmacogenomic information relating to pharmacokinetics, hepatic metabolism, and seizure etiology may improve safety and efficacy by individualizing therapy. Studies evaluating the clinical implementation of pharmacogenomic information at the point‐of‐care and identification of biomarkers are also needed. These studies may make it possible to avoid adverse drug reactions, maximize drug efficacy, reduce drug–drug interactions, and optimize medications for each individual patient. This review will discuss the available literature and provide future insights on precision medicine use with antiseizure therapy in critically ill adult patients.
Mpox impact on different organ systems: Complications, mechanisms, and management
Authors: Reda Abdullah , Dhama Kuldeep
Published: March 2023

Mpox (previously known as monkeypox) continues to raise concerns since many cases are still being recorded globally. Various reports have shown changing epidemiology of the disease, together with different atypical clinical characteristics of affected patients. The condition has reportedly been self‐limited since most patients do not usually require hospitalisation. However, recent reports showed that some patients might suffer from related complications and require hospitalisation. Different systems were reportedly affected, including cardiac, neurological, respiratory, and renal events. In the present literature review, we aim to review these complications, discuss their potential mechanisms, and provide insight into the currently recommended diagnostic and management practices.
Object Detector Differences when Using Synthetic and Real Training Data
Authors: Ljungqvist Martin Georg , Nordander Otto , Skans Markus , Mildner Arvid , Liu Tony , Nugues Pierre
Published: March 2023

To train well-performing generalizing neural networks, sufficiently large and diverse datasets are needed. Collecting data while adhering to privacy legislation becomes increasingly difficult and annotating these large datasets is both a resource-heavy and time-consuming task. An approach to overcome these difficulties is to use synthetic data since it is inherently scalable and can be automatically annotated. However, how training on synthetic data affects the layers of a neural network is still unclear. In this paper, we train the YOLOv3 object detector on real and synthetic images from city environments. We perform a similarity analysis using Centered Kernel Alignment (CKA) to explore the effects of training on synthetic data on a layer-wise basis. The analysis captures the architecture of the detector while showing both different and similar patterns between different models. With this similarity analysis, we want to give insights on how training synthetic data affects each layer and to give a better understanding of the inner workings of complex neural networks. The results show that the largest similarity between a detector trained on real data and a detector trained on synthetic data was in the early layers, and the largest difference was in the head part. The results also show that no major difference in performance or similarity could be seen between frozen and unfrozen backbone.
The role of art in coastal and marine sustainability
Authors: Matias Ana , Carrasco A. Rita , Pinto Bruno , Reis Jaime
Published: March 2023

Sustainability is a universal goal that requires balancing social, economic and environmental dimensions, and that applies to both terrestrial and marine environments. Several authors argue that arts are valuable tools to frame and engage with current environmental issues related to sustainability, including pollution, climate change and biodiversity loss. Accordingly, our research question is: What is the role of art in the sustainability of coasts and seas? We searched our research question on the two most important scientific databases of articles (Scopus and Web of Science) and retrieved 1,352 articles. We narrowed the articles to 79 studies that actually address our question through screening. The dataset describes a variety of artworks from the four art categories (literary, media, performing and visual) around the world, although the more frequent countries are the US, the UK and Australia. We found that visual arts are more common (~40%), and engagement is a highlighted pursued impact (~40%) by these artistic practices. Other authors also intend to promote marine conservation and restoration, management, education and activism. Only 19 articles of the dataset measured the impact of artistic activities on their audience. This subset shows evidence of art contributions to sustainability mainly through raising awareness, learning, and promoting engagement and enjoyment of project participants. Through this work, we set the current state of knowledge on this emerging topic, and argue that further research and new strategies of impact measurement are needed to thoroughly understand the effect of art on coastal/marine sustainability.
Diversity Matters: The Election of Asian Americans to U.S. State and Federal Legislatures
Authors: LUBLIN DAVID , WRIGHT MATTHEW
Published: March 2023

Despite substantial research on descriptive representation for Blacks and Latinos, we know little about the electoral conditions under which Asian candidates win office. Leveraging a new dataset on Asian American legislators elected from 2011 to 2020, combined with pre-existing and newly conducted surveys, we develop and test hypotheses related to Asian American candidates’ ingroup support, and their crossover appeal to other racial and ethnic groups. The data show Asian Americans preferring candidates of their own ethnic origin and of other Asian ethnicities to non-Asian candidates, indicating strong ethnic and panethnic motives. Asian candidates have comparatively strong crossover appeal, winning at higher rates than Blacks or Latinos for any given percentage of the reference group. All else equal, Asian American candidates fare best in multiracial districts, so growing diversity should benefit their electoral prospects. This crossover appeal is not closely tied to motives related to relative group status or threat.
Beyond the Constitutional Architecture:An Act respecting First Nations, Inuit and Métis children, youth and familiesat the Supreme Court of Canada
Authors: Cattapan Alana , Patrick Jamesy , Yuen Brenda
Published: March 2023

In December 2022, the Supreme Court of Canada heard arguments in a reference case about the constitutionality ofAn Act respecting First Nations, Inuit and Métis children, youth and families(the Act). At issue is whether the Act infringes on provincial jurisdiction and changes the constitutional architecture by giving First Nations law governing child welfare the force of federal law. In this short Currents article, we argue that the Supreme Court's consideration of the Act marks a critical juncture in the ongoing relationship between Canadian and Indigenous law. Through an examination of the arguments made before the Supreme Court, we assert that it is essential that the Court move beyond its historical commitments to protecting the Constitution and umpiring jurisdictional disputes and toward a recognition of the failures of the constitutional framework to account for an expansive understanding of inherent rights and inherent jurisdiction, including child welfare.
Person-centered and measured life’s simple 7 cardiovascular health concordance and association with incident cardiovascular disease
Authors: Deraz Omar , Van Sloten Thomas , Climie Rachel , Debras Charlotte , Fezeu Léopold K. , Deschasaux-Tanguy Mélanie , Jouven Xavier , Kesse-Guyot Emmanuelle , Galan Pilar , Hercberg Serge , Touvier Mathilde , Empana Jean-Philippe
Published: March 2023

Person-centered cardiovascular health (CVH) may facilitate cardiovascular disease primordial prevention in low resources settings. The study aims to assess the validity of person-centered CVH compared to gold standard measured CVH by examining the concordance between person-centered vs. measured CVH together with their respective association with incident cardiovascular disease events (CVD). Life’s Simple 7 (LS7) CVH metrics, including non-smoking, Body Mass Index, diet, physical activity, blood glycemia, blood pressure, and blood cholesterol were collected from 19,473 adults participating in the e-cohort NutriNet-Santé study from 2011 to 2014 and were followed until September 2020. Clinical examinations and blood analyses defined the measured biological metrics, while diagnoses, medication, or treatment for type 2 diabetes, hypertension, and hypercholesterolemia defined person-centered biological metrics. Declared behavioral metrics were common for both measured and person-centered CVH. The study included 18,714 CVD-free participants (mean age 51 years, 73% women), among whom 16.52% and 38.75% had 5–7 ideal LS7 metrics according to measured and person-centered CVH, respectively. Weighted concordance of person-centered and measured CVH was 0.87 [0.86; 0.88]. Over median follow-up of 8.05 years, 749 CVD events occurred. There was a 7% (HR 0.93 [0.88; 0.99]) and 13% (HR 0.87 [0.83; 0.92]) risk reduction of CVD risk by additional measured and person-centered ideal metrics, respectively. In conclusion, person-centered CVH may represent a reliable alternative to measured CVH.
A 350,000-year history of groundwater recharge in the southern Great Basin, USA
Authors: Jackson Tracie R. , Steidle Simon D. , Wendt Kathleen A. , Dublyansky Yuri , Edwards R. Lawrence , Spötl Christoph
Published: March 2023

Estimating groundwater recharge under various climate conditions is important for predicting future freshwater availability. This is especially true for the water-limited region of the southern Great Basin, USA. To investigate the response of groundwater recharge to different climate states, we calculate the paleo recharge to a groundwater basin in southern Nevada over the last 350,000 years. Our approach combines a groundwater model with paleo-water-table data from Devils Hole cave. The minimum water-table during peak interglacial conditions was more than 1.6 m below modern levels, representing a recharge decline of less than 17% from present-day conditions. During peak glacial conditions, the water-table elevation was at least 9.5 m above modern levels, representing a recharge increase of more than 233–244% compared to present-day conditions. The elevation of the Devils Hole water-table is 3–4 times more sensitive to groundwater recharge during dry interglacial periods, compared to wet glacial periods. This study can serve as a benchmark for understanding long-term effects of past and future climate change on groundwater resources.
Machine learning approaches to the prediction of powder flow behaviour of pharmaceutical materials from physical properties
Authors: Pereira Diaz Laura , Brown Cameron J. , Ojo Ebenezer , Mustoe Chantal , Florence Alastair J.
Published: March 2023

A Machine Learning (ML) approach was proposed to optimize the manufacturing-route selection from the physical particle properties of a pharmaceutical material.
Combination search strategy‐based improved particle swarm optimisation for resource allocation of multiple jammers for jamming netted radar system
Authors: Zou Wei‐qi , Niu Chao‐yang , Liu Wei , Wang Yan‐yun , Zhan Jia‐qi
Published: March 2023

This paper presents a new algorithm named combination search strategy (CSS)‐based improved particle swarm optimisation (IPSO) to address the resource allocation problem of multiple jammers. First, the authors propose a CSS to effectively broaden the limited search range of the two‐step solving framework. This method not only simplifies the solution framework but also considers the combined relationship between beam pointing and transmit power to determine the global solution to the original problem directly. Second, the authors propose the IPSO because the complexity of the decision variables is increased by CSS. This method can change the focus of searching the optimal solution at different stages, correct the direction of particle evolution over time and avoid the interference between the variables. Finally, this study simulates the problem of resource allocation of multiple jammers based on the CSS‐IPSO. Based on the simulation results, the combined search strategy can obtain better resource allocation results in a short time, and the IPSO algorithm can further improve the accuracy and stability of the resource allocation results.
Strength determination of metal composite multiple-row joints
Authors: Grishin V. , Glebova M. , Guseva N.
Published: March 2023

The results obtained using standard and improved (modified) calculation methods for load distribution on fasteners and joints strength are analyzed on the examples of four types of multiple-row metal-composite joints with cover plates of various thickness and various diameters of fasteners. A modified technique based on the Nuismer criterion is used to determine the load-bearing capacity. It was determined that for all joints the difference between the calculation results and the experiment is 14 - 26% using this criterion. It’s desirable to use a modified scheme of the Nuismer criterion to improve a calculation convergence of the load-bearing capacity with experimental data. In this case, the maximum difference between the calculation results and the experimental data for the considered joints was 12.9%.
Research of the structure and properties of wear-resistant surfaces
Authors: Chekulaeva A. , Permitina A.
Published: March 2023

The share of horizontal wells has been significantly increasing as the drilling technologies used in Russia have improved over the past ten years. In this regard most of drilling contractors use hard-alloy surfacing - hardbanding - a wear-resistant metal coating, deposited in the form of belts on the outer surface of the joint, to protect the drill string.
Search for design solutions to prevent the Kessler effect
Authors: Terekhova N. , Brekalov V. , Kumashkova A. , Dyukov M.
Published: March 2023

The article deals with the problems of near-earth space associated with the formation of objects called "space debris". The main sources of the appearance of "space debris" in near-earth orbits are highlighted. Examples of the negative impact of "space debris" on functioning spacecraft and stations are given. The general statistics of observations of near-Earth space, obtained by specialized complexes for recognizing space objects, are presented. Conceptual design solutions are proposed to prevent the Kessler effect.
Hydroerosion probabilistic modeling during surface layer quality ultrajet mesodiagnostics of aviation, rocket, and space equipment
Authors: Galinovskiy A. , Barzov A. , Yanko M. , Glotova M.
Published: March 2023

At present, deterministic approaches to the hydroerosion processes modeling, which is the informative-physical basis of ultrajet mesodiagnostics (UJM), significantly prevail over other methods of analysis. This contradicts the probabilistic nature of local hydroerosion, which is caused by the formation of an array of eroded particles with highly variable mass-geometric parameters reflecting the realities of the initial microdefects distribution in the surface layer of the analyzed object (OA). Therefore, probabilistic modeling is a physically more reasonable tool for describing multi-factor processes in the ultrajet interactions zone, including the peculiarities of ultrajet hydroerosion. Hence, this paper proposes a probabilistic approach to modeling the process of hydroerosion damage, based on the separation of the particle from the material surface as a result of the interaction of necessary and sufficient conditions for dispersion. The obtained calculation data (probabilistic analysis) are close to the results of live experiments, which, in turn, allows recommending this approach of mathematical formalization of the minimally invasive quality control method using complicated configuration parts surface properties ultrajet mesodiagnostics, and also OA produced from anisotropic materials, widely used in aviation, rocket, and space technology.
Aluminium matrix hybrid composite materials reinforced with carbides and intermetallics
Authors: Mikheev R. , Kalashnikov I.
Published: March 2023

Composite materials based on aluminum, reinforced withparticles of titanium carbide and intermetallic compounds of titanium aluminide, are made by casting technology. Investigations of the structure, mechanical and tribotechnical characteristics of the manufactured composite materials have been carried out. It is shown that the reinforcement of an aluminum matrix with TiC particles, or intermetallic phases of Al3Ti, formed by introducing reactive titanium powders into the melt, is an effective way to increase the tribotechnical characteristics. It has been established that the reinforcement of the aluminum matrix with TiC particles has a greater effect on the reduction of the friction coefficient and the wear rate, in comparison with the reinforcement with intermetallic phases Al3Ti, despite the higher volume fraction of the latter. It has been determined that the greatest wear resistance is provided by hybrid reinforcing of an aluminum matrix with TiC particles and intermetallic phases. The additional introduction of stronger TiC particles leads to a decrease in the load on the Al3Ti intermetallics, thereby preventing their destruction under the action of high external loads. In addition, the presence of a larger number of reinforcing phases in hybrid composite materials than in other composite materials samples provides not only a decrease in the load on each reinforcing particle separately, but also a decrease in the fraction of the matrix in the friction surface, thereby expanding the range of triboloading.
Experimental research of sandwich specimens’ failure mechanisms with facing layers from unidirectional fiber reinforced plastic with [0°] lay-up under axial compression
Authors: Paimushin V. , Kholmogorov S. , Makarov M.
Published: March 2023

An experimental technique for compression tests of the sandwich specimens with thin outer layers made of fiber reinforced composite is proposed. The proposed method is focused on testing thin layers of composite material, specimens of which, even with a very short gage length, lose their stability, thereby distorting the determined value of the ultimate stress. Experimental studies of the failure mechanism of sandwich specimens with outer layers with [0°] lay-up under axial compression have been carried out. The possibility of realizing the shear buckling mode for specimens with different geometric parameters was revealed, which allows the determined ultimate stress formed in the outer layers to be taken as a mechanical characteristic when calculating the strength of structures made of composite materials. It is shown that for specimens with a honeycomb core in the outer layers under compression, an in-phase flexural buckling mode occurs. The implementation of a non-classical shear buckling mode is possible only for specimens with a rigid core, which was used as balsa wood.
Assessment of the stress-strain state of machine structural elements made of polymer composite materials with a hybrid matrix by numerical simulation
Authors: Kosenko E. , Nelyub V. , Zorin V.
Published: March 2023

The expansion of the fields of application of polymer composite materials (PCM) requires the development of their new compositions, structures, and molding methods. One of the most difficult tasks in the design of PCM products is the selection or development of a polymer matrix that meets a number of technological and operational requirements. The addition of components forming an independent conditionally liquid phase to the composition of the PCM matrix makes it possible to change the set of properties of the composite and ensure its high crack resistance. The paper presents the results of evaluating the stress-strain state of model samples of carbon fiber reinforced plastic with an organosilicon polymer material that forms a hybrid matrix with the base material of the binder. Modeling was carried out for cases of using organosilicon material with low and high modulus of elasticity. Also, modeling of a front-end loader bucket made using carbon fiber with the considered hybrid matrix was performed. The simulation results showed that the use of PCM with organosilicon material in the manufacture of a product can significantly reduce its weight and provide a sufficient margin of safety.
Influence of additives of amphiphilic block copolymers on the porosity of hollow ultrafiltration membranes based on polyethersulfone
Authors: Fateev N. , Ivanov M. , Korotkova N. , Dibrov G. , Pavlukovich N. , Storozhuk I.
Published: March 2023

It has been shown that the addition of hydrophilic polyarylatepolyalkylene oxide and polyethersulfone-polyalkylene oxide block copolymers to polyethersulfone can control the porosity of the selective layer of hollow fiber ultrafiltration membranes. The selection of the optimal amount of the additive makes it possible to increase the performance of membranes in the purification of drinking water from microalgae, large mineral particles, bacteria and viruses.
Coupled micro-macroscopic modeling of layered composites with finite deformations
Authors: Dimitrienko Yu. , Karimov S. , Kolzhanova D.
Published: March 2023

A coupled micro- and macroscopic modeling of an incompressible layered composite material under finite deformations is performed based on the asymptotic homogenization method and universal semi-linear models. The deformation diagrams of the periodicity cell are calculated. A method for searching for effective transversally isotropic properties of LCM based on the obtained diagrams is considered. Cylindrical bending of an LCM plate is simulated using the model of a transversally isotropic medium. The microstresses in the periodicity cell are calculated based on the homogenized stresses.
Modeling of thermal processes in anti-icing gratings for arctic purposes
Authors: Dimitrienko Yu. , Chibisov V. , Yurin Yu. , Anokhin D.
Published: March 2023

The problem of modeling thermal processes in anti-icing gratings, which are used in arctic conditions, is considered. The task is of practical importance, including for the design of air intake grilles for ship systems operating in arctic conditions. A mathematical model of thermal processes is presented, which takes into account the processes of heat transfer in the lattice due to the thermal conductivity of its internal elements, due to convective heat exchange with the external air, due to heat release during electric heating, and also due to phase transformations during icing and melting of ice. The problem is solved in a three-dimensional formulation, using a software package developed at Bauman Moscow State Technical University. Some results of numerical simulation are presented.
Multilayer metal materials recrystallization mechanism
Authors: Plokhikh A. , Petrov S. , Vlasova D.
Published: March 2023

This project deals with various aspects of the multilayer structure during hot package rolling in the multilayer materials with over 1000 layers, as exemplified by a multilayer structure composed of the 30HGSA and 08H18 steels. The subject of analysis was the structural state maps of steels that make up the researched structure. The results of research conducted by means of the micro X-ray spectroscopy and microdiffraction analysis establish the causes of the structural damages in the samples, which are primarily related to the ongoing flattening diffusion of the alloying elements, and serve as the basis for a model of multilayer materials recrystallization, based on a hypothesis postulating that the interlayer boundary is where new dynamic recrystallization grains form. Recommendations are given on performing hot package rolling when producing multilayer materials.
Mineral filler effect on mechanical and rheological properties of thermoplastic HDPE/barley straw composites
Authors: Kuzmin A. , Goncharova Yu. , Slavkina V. , Chalganov D.
Published: March 2023

The paper is devoted to the properties of the wood-polymer composite based on polyethylene and barley straw. The effect of a mineral additive, namely shungite powder with a particle size of less than 20 microns, was studied. The developed composites were obtained on a laboratory two-rotor batch mixer. The mechanical and rheological properties of the composites (tensile strength and modulus of elasticity, water absorption, density, effective viscosity and modulus of elasticity) have been studied. It has been shown that the adding of shungite powder contributes to increase in the composites mechanical properties, in particular, the tensile strength increases. With an increase in the concentration of shungite, the viscosity of the composition melt decreases. The obtained thermoplastic materials can be used in construction and furniture production, as well as in the automotive industry.
Effect of water and soil microbiota on structure and properties of PLA fiber composites
Authors: Tertyshnaya Y. , Khramkova A. , Podzorova M.
Published: March 2023

Nonwoven fibers from biodegradable polymers such as polylactide and natural rubber were obtained by electrospinning. The fiber morphology was studied by optical microscopy. Thermal properties were studied by differential scanning calorimetry. It is shown that after the action of water for 180 days, the glass transition temperature is not observed on DSC thermograms. The degree of crystallinity of all samples increases by 9- 12% depending on the composition. After exposure to soil, the glass transition temperature changes little for pure PLA and a sample containing 5 wt.% of natural rubber and decreases by 2-3 оC in samples with a rubber content of 10 and 15 wt.%. The melting point of PLA fiber increases by 2 оC during degradation in the soil, and in fibrous composites it decreases by 1.5 оC. Changes in the values of the degree of crystallinity have a similar tendency. Thus, under the same temperature and time conditions, water has a stronger effect compared to soil on the structure of nonwoven fibrous materials PLA/NR.
Comparative analysis of methods for calculating the physico-mechanical characteristics of multi-layered composite materials
Authors: Htet Tun Lin , Prosuntsov P.
Published: March 2023

The paper presents a comparative analysis of methods and results of calculating the physical and mechanical characteristics of single-layered and multi-layered polymer composite materials (PCM). The object of the study is a polymer composite which consists of epoxy binder and carbon fiber reinforcements. The principle of multiscale modelling is applied to determine the physical and mechanical characteristics of the composite. Within the framework of this study, a representative volume element (RVE), the structure of which corresponds the characteristics of real materials, is used. The initial data for the calculation in this case are physical and mechanical characteristics of anisotropic fibers (carbon fabric) and an isotropic binder, as well as the geometric model of the RVE. As a result of the calculation, the effective characteristics of a quasi-homogeneous anisotropic material suitable for numerical analysis of the composite structures are determined. A comparison of the results of determining the physical and mechanical characteristics of the polymer composite using ANSYS Material Designer and MSC Digimat software packages for various size of RVE model is carried out and ANSYS Workbench software is also used to perform the stress-strain conditions of RVE model to determine the physico-mechanical characteristics of polymer composites.