bluuebunny/crossref_metadata_2025 huggingface dataset:
Can earthen plasters be effectively applied on different substrates?
Authors: Jia Quanquan , Chen Wenwu , Zhang Jingke , Tong Yanmei , Guo Qinglin
Published: October 2023

Earthen plasters have been widely used in historical buildings, especially in wall paintings in northwest China. However, the properties of earthen plasters have deteriorated dramatically under long-term weathering. In order to investigate one of the key issues in plaster restoration, i.e., whether the plaster can be effectively applied on different substrates, seven compositions of plasters were prepared and applied to three types of substrates modeled after actual wall painting supports. Shrinkage of the plasters was measured and the adhesion of the plasters to the substrates was characterized by a shear test using a designed device. The results show that the shrinkage of the plaster depends on the material composition of the plaster and is almost independent of the type of substrate. The addition of vegetal fibers to earthen plaster can effectively improve interfacial adhesion. The type and the surface roughness of the substrate have a significant effect on the adhesion between the earthen plaster and the substrate.
Antibody-conjugating nanogel (Conjugel) with two immune checkpoint inhibitors for enhanced cancer immunotherapy
Authors: Kim Jongseong , Park Yongdoo , Chae Yun Jin , Lee Kang-Gon , Oh Doogie , Lee Su-Kyoung
Published: October 2023

Cancer immunotherapy by immune checkpoint inhibitors (ICI) acts on antitumor responses by stimulating the immune system to attack cancer cells. However, this powerful therapy is hampered by its high treatment cost and limited efficacy. Here, we show the development of an antibody-conjugating system (Conjugel) that potentiates the efficacy of bispecific immunotherapy that simultaneously targets CTLA-4 and PD-L1. The Conjugel, consisting of highly deformable nanogels and antibody-binding protein, was loaded with two ICI monoclonal antibodies (mAb). Compared with mAb treatment alone, treatment with a bispecific Conjugel loaded with the both ICIs significantly decreased both the survival of MCF-7 and MDA-MB-231 breast cancer cells in vitro and the size of 4T1-Luc2-derived orthotopic syngeneic tumors in vivo. Furthermore, the ICI-loaded Conjugel was less toxic in vivo than the combination treatment delivered as a bolus. Our findings have important implications for Conjugel-based immunotherapy, developing the safer and higher efficacy of ICIs to treat breast cancers.
Synergistic use of anti-inflammatory ketorolac and gentamicin to target staphylococcal biofilms
Authors: Sekar Amita , Gil Dmitry , Tierney Peyton Anne , McCanne Madeline , Daesety Vikram , Trendafilova Darina , Muratoglu Orhun K , Oral Ebru
Published: October 2023

Background
While antibiotics remain our primary tools against microbial infection, increasing antibiotic resistance (inherent and acquired) is a major detriment to their efficacy. A practical approach to maintaining or reversing the efficacy of antibiotics is the use of other commonly used therapeutics, which show synergistic antibacterial action with antibiotics. Here, we investigated the extent of antibacterial synergy between the antibiotic gentamicin and the anti-inflammatory ketorolac regarding the dynamics of biofilm growth, the rate of acquired resistance, and the possible mechanism of synergy.
Methods
Control (ATCC 12600, ATCC 35984) and clinical strains (L1101, L1116) of S. aureus and S. epidermidis with varying antibiotic susceptibility profiles were used in this study to simulate implant-material associated low-risk and high-risk biofilms in vitro. The synergistic action of gentamicin sulfate (GS) and ketorolac tromethamine (KT), against planktonic staphylococcal strains were determined using the fractional inhibitory concentration measurement assay. Nascent (6hr) and established (24hr) biofilms were grown on 316 stainless steel plates and the synergistic biofilm eradication activity was determined and characterized using adherent bacteria count, MBEC measurement for GS, gene expression of biofilm-associated genes, visualization by live/dead imaging, scanning electron microscopy, and bacterial membrane fluidity assessment.
Results
Gentamicin-ketorolac combination demonstrated synergistic antibacterial action against planktonic Staphylococci. Control and clinical strains showed distinct biofilm growth dynamics and an increase in biofilm maturity was shown to confer further resistance to gentamicin for both ‘low-risk’ and ‘high-risk’ biofilms. The addition of ketorolac enhanced the antibiofilm activity of gentamicin against acquired resistance in staphylococcal biofilms. Mechanistic studies revealed that the synergistic action of gentamicin-ketorolac interferes with biofilm morphology and subverts bacterial stress response altering bacterial physiology, membrane dynamics, and biofilm properties.
Conclusion
The results of this study have a significant impact on the local administration of antibiotics and other therapeutic agents commonly used in the prevention and treatment of orthopaedic infections. Further, these results warrant the study of synergy for the concurrent or sequential administration of non-antibiotic drugs for antimicrobial effect.
Multi-innovation-based online variable projection algorithm for a class of nonlinear models
Authors: Su Jian-Nan , Su Xiang-Xiang , Chen Guang-Yong , Gan Min , Chen C. L. Philip
Published: October 2023

Separable nonlinear models (SNMs) are powerful tools for system identification, data analysis, and machine learning, thanks to their flexible structure and remarkable ability to capture nonlinear behaviors. However, compared with the offline one, the online identification of SNMs is more challenging, due to the dynamic nature of the nonlinear systems and the interdependence of the different parts of parameters in SNMs. Existing methods, such as the recursive Gauss-Newton (RGN) and recursive variable projection (RVP) methods, which cannot effectively handle the parameter interdependence, often suffer from slow convergence and poor performance in this scenario. In this paper, we propose a novel multi-innovation-based recursive variable projection (MIRVP) algorithm, which extends the RVP algorithm with a multi-innovation strategy. This strategy enables the algorithm to handle the interaction of the linear and nonlinear parameters more effectively, by using multiple past innovations instead of only the current one, thus improving the identification effect. We demonstrate the effectiveness of our MIRVP algorithm on both synthetic and real world datasets, showing its advantages in convergence speed and robustness over existing methods.
Quasi-Isomorphisms of Commutative DG Rings and Divided Power Structures
Authors: Yekutieli Amnon
Published: October 2023

We prove that a quasi-isomorphism f : A → B between commutative DGrings, where B admits a divided power structure, can be factored as f = f ̃ ◦ e, wheree : A → B ̃ is a split injective quasi-isomorphism, and f ̃ : B ̃ → B is a surjectivequasi-isomorphism.This result is used in our work on a DG approach to the cotangent complex, and ourwork on the derived category of commutative DG rings.
Study of Dispersion and Adsorption of Aerosols during Oral Practice
Authors: He junjie , Li Jiachun , Chen Bo , Yang Wei , Yu Xiaoyan , Zhang Fan , Li Yugang , Shu Haiyin , Zhu Xiankun
Published: October 2023

Objectives
In this study, we investigated the dispersion patterns of aerosols and droplets during oral practice, simulated the adsorption characteristics of suction devices, and evaluated the effectiveness of suction devices in reducing aerosols during dental procedures.
Materials and Methods
Firstly, the continuous images of oral aerosols and droplets were photographed with a high-speed camera, and the trajectories of these particles were recognized and processed by Image J to determine key parameters affecting particle dispersion: diffusion velocity, distance, and angle. Secondly, based on the parameters data, the flow field of aerosol particles around the oral cavity was simulated using computational fluid dynamics (CFD), and the flow field under adsorption conditions was simulated to demonstrate the aerodynamic characteristics and adsorption efficiencies of the single-channel and three-channel adsorption ports at different pressures. Finally, according to the simulated data, a three-channel suction device was developed, and the adsorption efficiency of the device was tested by the fluorescein tracer method.
Results
The dispersion experimental data showed that aerosol particles' maximum diffusion velocity, distance, and angle were 6.2 m/s, 0.55 m, and 130°, respectively. The simulated aerosol flow-field distribution was consistent with the aerosol dispersion patterns. The adsorption simulation results showed that the adsorption efficiency of the single-channel adsorption port could reach 74.05% at -350 pa, and the three-channel port was 99.23% at -350 pa and − 150 pa. The adsorption experimental data showed that the adsorption efficiency of three-channel suction device was 97.71%.
Conclusions
A three-channel suction device was designed by simulations and experiments, which can capture most aerosols in the dental clinic and prevent them from spreading.
Clinical relevance
Using three-channel suction devices during oral treatment effectively reduces the spread of oral aerosols, which is essential to prevent the spread of epidemics and ensure the health and safety of patients and dental staff.
A class of viscoelastic evolution equation on manifolds with conical singularities
Authors: Liao Menglan , Hajjej Zayd
Published: October 2023

In this paper, a class of viscoelastic evolution equation on manifolds with conical singularities is concerned. Local existence and uniqueness of the weak solution are established by making use of the Faedo-Galerkin method and the contraction mapping principle. Moreover, by constructing an auxiliary functional and exploiting Levine’s concavity method, the finite time blow-up criteria are obtained for arbitrary initial energy. In particular, the upper and lower bound of the blow-up time are also derived.
MSC(2020): 35R01; 35L20; 35B44.
Prevalence and Risk Factors of Dry Eye Disease in an Ophthalmological Center in Southern Brazil
Authors: Mahmud Islam Maruf Ahmad Maruf , Silva¹ Anaís Back , Abed³ Sabrina , Quinto¹ Guilherme G. , Morchbacher¹ Ricardo , Hazarbassanov² Rossen , Gomes² José Álvaro Pereira
Published: October 2023

Purpose: To determine the prevalence of Dry Eye Disease (DED) and its possible risk factors in the population of Rio Grande do Sul, Brazil.
Methods:A cross-sectional study was carried out through the patients who were referred to ophthalmic care at tertiary level. The patients were evaluated through the application of OSDI (Ocular Surface Disease Index) questionnaire. A specific questionnaire was created to register information on participants' demographics as well as risk factors associated, such as
age, gender, ethnicity, education, medications, systemic diseases, eye disease, contact lenses, daily screen time, physical exercise, smoking, pregnancy, previous ocular surgery.
Results: A total of 300 individuals participated in this study [mean (SD) age 62.71 (15.04) years, range 12-93 years; 64,33% females]. The prevalence of syntomatic dry eye was 53.65% (mean OSDI score of 21.01): 36.66% had mild dry eye, 13,66% moderate and 3.66% severe symptoms. There was a significant positive association between symptomatic dry eye and smoking [95% CI (1.100 – 1.708); p<0.05], which means that smoking increased the risk of dry eye (mild, moderate or severe) by 37%. The other risk factors did not show a statistically significant correlation with the development of dry eye disease.
Conclusion: This study demonstrated a high prevalence of DED in patients seeking tertiary ophthalmological care in Southern Brazil. This represents a high proportion of the population with DED and a significant public health problem that requires attention from public authorities. Regarding the risk factors associated, only smoking increased the risk of developing the dry eye.
Galois cohomology of SO(N)-connections
Authors: Saito Cyprien
Published: October 2023

Two different types of Fuchsian function of the second kind are possible for SU(2)-bundle on U(1)-flat-connections of Chern-Simons field. Both of two different types of Fuchsian are parametrized by the same moduli as the LF-invariant measure situated on arbitrary Galois cohomology. One is characterized by polylogarithmic functions and the other is by the immanent monodromy preserving deformations within the similar preparatory polylogarithmic conditioning. After the comparaison between the Fuchsians, it will be known that the categorical commutativity of modules fixed by a certain Galois cohomology works for the regulator of the formality of Galois cohomology existing arbitrarily in common for two Fuchsians and there exists closed oriented 3-manifolds as the invariance for SO(N)-connections fixed by arbitrary Galois cohomology for one SO(N)-connection and parametrized by Chern-Simons field.
Development of a lightweight convolutional neural network-based visual model for sediment concentration prediction by incorporating the IoT concept
Authors: Huang Cheng-Chia , Chang Che-Cheng , Chang Chiao-Ming , Tsai Ming-Han
Published: October 2023

Sediment concentration (SC) monitoring has always been a pressing issue in water resource management, as many existing instruments still face challenges in accurately measuring due to environmental factors and instrument limitations. A robust technology is worth presenting to apply in the field site. This study firstly uses mean-absolute-error (MAE), root-mean-square error (RMSE), correlation coefficient (CC), and Nash–Sutcliffe efficiency coefficient (NSE) to describe the performance of the proposed convolutional neural network (CNN). Moreover, adapting the ensemble learning concept to compare the multiple machine learning (ML) approaches, the CNN presents the highest predicted accuracy, 91%, better than SVM (79%), VGG19 (63%) and ResNet50 (35%). As a result, the proposed CNN framework can appropriately apply the monitoring needs. The primary purpose is to develop a simple, accurate, and stable SC monitoring technology. Instead of some complex architectures, a simple and small neural network is adopted to implement real-time application (RTA). Via our design, such a traditional but critical issue can be improved to a new state. For example, by incorporating the concept of the Internet of Things (IoT) with our design, the distributed computing system for large-scale environmental monitoring can be realized quickly and easily.
Educação bilíngue e os desafios da internacionalização da educação básica
Authors: Fistarol Caique Fernando da Silva , Barbosa Isabela Vieira , Heinzle Márcia Regina Selpa
Published: October 2023

Ao abordarmos o ensino de uma segunda língua, poucos estudos se voltam para a formação inicial de professores que atuam em contextos sociolinguisticamente complexos. Assim, o presente artigo tem como objetivo analisar as diretrizes pedagógicas que regem o currículo nacional brasileiro para formação de professores de Pedagogia e do curso de Letras - Inglês. Partimos do pressuposto de que o pedagogo e o professor de língua adicional são os profissionais adequados para lecionar nos anos iniciais em escolas bilíngues. Os procedimentos metodológicos se baseiam na análise documental e têm como dados as Resoluções que regem o currículo nacional brasileiro e que repercutem na formação de professores de Pedagogia e do curso de Letras - Inglês. Conclui-se que há superficialidade dos cursos em relação a aspectos multiculturais, que permitam pensar os sujeitos docentes e de aprendizagem como sujeitos sociais e historicamente situados.
Exosomal Non-coding RNAs: A New Approach to Melanoma Diagnosis and Therapeutic Strategy
Authors: Liu Jie , Hu Xiaoping , Xin Wenqiang , Wang Xianbin
Published: October 2023

:

Malignant melanoma (MM) is a highly aggressive cancer with a poor prognosis.
Currently, although a variety of therapies are available for treating melanoma, MM
is still a serious threat to the patient’s life due to numerous factors, such as the recurrence
of tumors, the emergence of drug resistance, and the lack of effective therapeutic
agents. Exosomes are biologically active lipid-bilayer extracellular vesicles secreted by
diverse cell types that mediate intercellular signal communication. Studies found that exosomes
are involved in cancer by carrying multiple bioactive molecules, including non--
coding RNAs (ncRNAs). The ncRNAs have been reported to play an important role in
regulating proliferation, angiogenesis, immune regulation, invasion, metastasis, and treatment
resistance of tumors. However, the functional role of exosomal ncRNAs in MM remains
unknown. Therefore, this review summarizes the current state of melanoma diagnosis,
treatment, and the application of exosomal ncRNAs in MM patients, which may
provide new insights into the mechanisms involved in melanoma progression and serve
as biomarkers for diagnosis and therapeutic targets.
Fabrication and In vitro Evaluation of Carbopol/Polyvinyl Alcohol-based
pH-sensitive Hydrogels for Controlled Drug Delivery
Authors: Suhail Muhammad , Chiu I-Hui , Liu Jia-Yu , Ullah Hamid , Lin I-Ling , Minhas Muhammad Usman , Tsai Ming-Jun , Wu Pao-Chu
Published: October 2023

Background::

Diclofenac sodium has a short half-life (about 1.5 hours), requiring repeated administration,
and as a result, serious complications, such as GI bleeding, peptic ulcer, and kidney and liver dysfunction,
are generated. Hence, a sustained/controlled drug delivery system is needed to overcome the complications
caused by the administration of diclofenac sodium.

Aims::

This study aimed to fabricate and evaluate carbopol/polyvinyl alcohol-based pH-sensitive hydrogels for
controlled drug delivery.

Objective::

pH-sensitive carbopol/polyvinyl alcohol graft-poly(acrylic acid) hydrogels (Cp/PVA-g-PAa hydrogels)
were developed for the controlled delivery of diclofenac sodium.

Methods::

The combination of carbopol/polyvinyl alcohol, acrylic acid, and ethylene glycol dimethacrylate
was used as polymer, monomer, and cross-linker, respectively. The effects of the formulation’s composition
on porosity, swelling index, and release pattern of diclofenac sodium from the developed hydrogels were investigated.

Results::

An increase in porosity and swelling was observed with the increasing amounts of carbopol and
acrylic acid, whereas polyvinyl alcohol showed the opposite effect. Due to the formation of a highly viscous
system, the drug release decreased with the increasing concentrations of carbopol and polyvinyl alcohol while
increased with increasing acrylic acid concentration. The pH-responsive properties of the fabricated hydrogels
were demonstrated by dynamic swelling and drug release studies at three different pH values. Higher dynamic
swelling and diclofenac sodium (model drug) release were found at high pH values compared to low pH values,
i.e., pH 7.4 > 4.6 > 1.2, respectively. Cytotoxicity studies reported no toxic effect of the prepared hydrogels,
thus indicating that the prepared hydrogels are safe to be used on clinical basis.

Conclusion::

The prepared carbopol/polyvinyl alcohol crosslinked hydrogel can be used as a promising carrier
for the controlled release of drugs.
Bioinformatic Analysis to Identify and Cellular Experiments to Validate
Autophagy-related Genes in Psoriasis
Authors: Bai Ruimin , Wu Shaobo , Liu Xinyi , Xing Zixuan , Luo Ruiting , Zhang Wen , Liu Meng , Ma Xinyu , Lei Hao , Wang Ning , Zheng Yan
Published: October 2023

Purpose:

To explore differentially expressed genes (DEGs) associated with autophagy in
psoriasis using bioinformatics analysis and verify them in an M5-induced psoriatic cell model.

Methods:

We obtained gene expression microarray data from patients with psoriasis and normal
skin tissues from the dataset GSE78097 of the NCBI Gene Expression Omnibus (GEO) database.
R software was used to identify DEGs associated with autophagy in psoriasis. Proteinprotein
interaction (PPI) and correlation analyses were used to show interactions between certain
genes. Their potential biological roles were determined using Gene Ontology (GO) and Kyoto
Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Finally, all the DEGs associated
with autophagy in psoriasis were validated in a psoriatic cell model by RT-qPCR.

Results:

28 DEGs associated with autophagy were identified. These genes were linked to one
another, and the most connected hub gene was VEGFA, according to PPI analysis. GO and
KEGG enrichment analyses revealed various biological pathways associated with autophagy.
The RT-qPCR findings of the expression of 18 genes in the psoriatic cell model confirmed
the bioinformatics analysis results. The five genes with the most significant differences were
IL24, CCL2, NAMPT, PPP1R15A, and SPHK1.

Conclusion:

We identified DEGs associated with autophagy in patients with psoriasis. IL24,
CCL2, NAMPT, PPP1R15A, and SPHK1 were identified as important genes that may influence
psoriasis development through the regulation of autophagy.
Deep Learning-based Automated Knee Joint Localization in Radiographic
Images Using Faster R-CNN
Authors: Sivakumari T. , Vani R.
Published: October 2023

Background::

Osteoarthritis is a condition that poses a risk to the knee joint, resulting in pain and impaired function. However, traditional knee X-ray evaluations
using the Kellgren-Lawrence grading system have proven to be inefficient. These evaluations are subjective, time-consuming, and labor-intensive,
particularly in busy hospital settings.

Objective::

The objective of this research was to present a deep learning-based approach that can detect knee joint regions in medical images. By addressing
the limitations of traditional methods, the aim was to develop a more efficient and automated approach for knee joint analysis.

Methods::

The proposed method utilizes the Faster R-CNN model, which consists of a region proposal network (RPN) and Fast R-CNN. The RPN generates
region proposals that potentially contain knee joint regions, while the Fast R-CNN network categorizes and extracts features from these proposals.
To train the model, a dataset of knee joint images was employed. The performance of the model was evaluated using metrics, such as accuracy,
precision, recall, F1-score, and mean IoU (Intersection Over Union).

Results::

The results demonstrated the high accuracy of the proposed method in detecting knee joint regions. The model achieved a mean IoU of 94.5,
indicating a strong overlap between the predicted and ground truth regions. These findings highlight the potential of deep learning-based
approaches in automating medical image analysis, specifically in the diagnosis and management of knee joint disorders.

Conclusion::

This study emphasizes the significance of leveraging advanced technologies, such as deep learning, in medical imaging. By developing more
efficient and accurate methods for identifying knee joint regions in medical images, it becomes feasible to enhance patient outcomes and healthcare
delivery. The proposed deep learning-based approach showcases promising results, paving the way for further advancements in the field of medical
image analysis and contributing to improved diagnostic capabilities for knee joint disorders.
Synthesis of Piperazine-containing Derivatives and their Antimicrobial,
Antimycobacterial, Antimalarial and Antioxidant Activities
Authors: Patel Navin B. , Maisuria Pratik N. , Gujarati Akash V. , Patel Divyesh K.
Published: October 2023

Background:

One of the most crucial heterocycles is piperazine for the creation of
novel medication candidates with a variety of medicinal applications. The piperazine moiety is a
cyclic compound with four carbon atoms and two nitrogen atoms in positions 1 and 4.

Objective:

The objective of this studty is the development of 1-((3,4-dimethoxyphenyl) (substitutedphenyl) substituted -piperazine (A1-A10) analogs via the one-pot synthesis method and evaluation for their preliminary antibacterial, antifungal, antimycobacterial, antioxidant, and antimalarial activity.

Methods:

Desired piperazine derivatives were obtained in a single step reaction using piperazine,
aldehydes, and boronic acid derivatives. The structures of all newly synthesized compounds have
been established based on analytical and spectral data. An in silico molecular docking study was
carried out for the series.

Results:

The spectral data using IR, 1
H NMR, and 13C NMR and mass spectra confirmed the
structure of the synthesized compounds. Compounds A6 and A10 were found to be the most promising agents for antimalarial activity. A1-A10 showed a higher IC50 value and found less antioxidant activity. Some of the compounds showed higher potency when compared to the standard
drugs in this antimicrobial study.

Conclusion:

The structure-activity study showed that changes in substituents either on aldehyde,
piperazine, or boronic acid derivatives can lead to potential active compounds. These facts make
the compounds interesting candidates for further evaluation of their efficacy in the treatment of
microbial, tubercular and malarial diseases.
A Brief Review of Flourishing Among Adolescents and Young
Adults with Mood and Anxiety Disorders
Authors: Lhaksampa Tenzin C. , Kelly-Hedrick Margot , Suchanek Melissa , Chisolm Margaret S. , Miller Leslie R.
Published: October 2023

The onset of common mental illnesses, such as mood and anxiety
disorders, often begins in adolescence and young adulthood. While traditional
clinical care focuses on reducing psychiatric symptoms, it is important to
simultaneously promote positive psychological states (i.e., flourishing). In this
brief review, we synthesize the published literature on flourishing among
adolescents and young adults with mood and anxiety disorders. Using
VanderWeele’s flourishing model domains, we developed search terms that we
applied to PubMed, PsycINFO, and Google Scholar databases. We identified four
articles that met the inclusion criteria for this review. Each study identified in this
review used distinct flourishing scales to examine various flourishing domains.
Overall, incorporating techniques to promote positive mental health in clinical
care decreased psychiatric symptoms and increased flourishing. More research is
needed to examine how incorporating flourishing into clinical care can reduce
suffering and promote positive mental health in patients.
An Empirical Analysis of Renewable Energy Grid Connected Supply: A Review
Authors: Khan Md. Shahrukh , Ahmad Anis , Kundu Shyamal Kumar
Published: October 2023

A grid is an interconnected network for electricity delivery from the producer
to the consumer. This review focuses on the challenges associated with the integration
of renewable energy into the grid, as well as the solutions that can be used
to reduce the environmental impact of climate change and achieve sustainability. Renewable
energy such as solar energy, wind energy, hydroelectricity, geothermal energy,
and tidal energy are the sources which can help us to achieve the reduction of CO2
emission in the atmosphere, which is directly linked to climate change and global
warming. In our study, we focussed on sustainable development and decreased CO2
emissions. The grid is essentially an interconnected network for delivering electricity
from the manufacturer to the consumer, and the manufacturing segment should be
replaced by renewable energy for us to meet our goal.
Impacts of Cavity Thickness and Insulating Material on Dielectric Modulated Trench Junction-less Double Gate Field Effect Transistor for Biosensing Applications
Authors: Bhattacherjee Swagata , Dhar Palasri , Roy Sunipa
Published: October 2023

Introduction:

This work represents the influence of gate dielectric, and the
nano-cavity gap of a dielectric modulated trench gate Junction-less Double Gate Field
Effect Transistor (JL-DGFET) on the different performance indicators is investigated
considering the Low-Frequency Noise.

Methods:

It is noted that the gate dielectric and the nanogap, both parameters, have a
substantial influence on the sensing capacity and performance of noise of the device.

Results:

A double gate suitable dielectric material and cavity thickness can effectively
improve the biosensor’s sensitivity with a minimum amount of noise.

Conclusion:

The sensitivity is found to increase up to 9.5 for dielectric constant, k =
3.57 and 6.5 for dielectric constant, k = 2.1.
Aeroelastic design and optimization of strut-braced high aspect ratio wings
Authors: Toffol F.
Published: October 2023

Abstract. To improve aircraft aerodynamic efficiency, a possible solution is to increase the wing aspect ratio to reduce the induced drag term. As a drawback, the span increase introduces an increment of the wing loads, specially of the wing root bending moment that drives the sizing of the wing. Structural mass must be added to withstand higher loads, reducing the aerodynamic advantage from a fuel consumption point of view, as it can be instinctively seen in the Breguet’s range equation. To limit the load increment due to the increased span, a possible solution is the usage of a strut: this kind of structure modifies the load path spanwise, diminishing the wing internal forces and reducing the wing penalty mass. In this framework, a lot of research is done studying Ultra-High Aspect Ratio Strut-Braced Wing, where the aspect ratio of such configuration is exasperated above 15, and the resulting wing is extremely flexible and may experience large deformation under loading. Moreover, the over determined structure realized by the fuselage-wing-strut connections deserves particular attention to fully characterize the aeroelastic interaction among the structural elements. For this reason, a two-step design approach that exploits NeoCASS (GUESS + NeOPT) is used to provide a sizing of the wing and of the strut considering several structural and aeroelastic constraints (e.g. flutter and ailerons effectiveness).
Scientific activity of Sapienza University of Rome aerospace systems laboratory on the study of lunar regolith simulants, focusing on their effect on the microwave fields propagation
Authors: Delfini A.
Published: October 2023

Abstract. The forthcoming space missions aiming at developing new habits on the Moon and into deep space are opening new challenges for materials scientists in enabling in-situ efficient systems and subsystems. During the last decades, Space Agencies programs of long-term missions addressed to the future Moon colonization moved the aerospace research interest toward the knowledge of how the lunar conditions could represent scientific and technological tasks to be tackled, to deal with such a big challenge. Among very many matters, a still open question is to understand how proper the lunar environment would be for TLC systems daily used on Earth, or whether it should be necessary to establish different stable systems on the Moon by finding alternative solutions with respect to the Earth conventional technologies. This paper introduces the scientific activity developed during recent years at the Aerospace Systems Laboratory of Sapienza University of Rome, concerning the study of lunar regolith with focus on its effect on the microwave fields propagation. The research addresses such task by simulating several representative Moon environmental conditions, reproducing well defined chemical/physical background in terms of atmospheric parameters and soil compositions, as from the available literature data, and analyzing the microwave propagation characteristics to design efficiently mobile TLC systems operating on the Moon. With the further objective of considering regolith as main routine resource for drawing up systems and facilities constituting lunar living structures, the analysis of regolith-microwave interaction is thus focused on two specific paths, such as building airtight structures by means of ISRU methodologies and the EM compatibility (EMC) analysis of simulated lunar environment & TLC systems design. This work can be thus considered as linked to the forthcoming projects aimed at enhancing the research community knowledge about the Moon environment, by assessing scientific background and establishing technological processes for lunar TLC systems development.
Preliminary design of a CubeSat in loose formation with ICEYE-X16 for plastic litter detection
Authors: Pelliccia F.
Published: October 2023

Abstract. Every year, more than 14 million metric tons of plastic are estimated to enter rivers, lakes, and seas [1], becoming one of the main sources of pollution with significant economic and ecological impact on sensitive habitats, welfare, and vulnerable, endangered species. In this context, keeping track of plastic litter hot-spots and their evolution in time - both in open sea and coastal areas - becomes of fundamental importance. Plastic detection from space is at an early stage and, although some interesting capabilities have been demonstrated by multi-spectral imagery, hyperspectral sensing, and GNSS reflectometry, such technologies do not yet allow for the operational detection and monitoring of plastic from space on a global scale, with sufficient temporal and spatial coverage. The characteristics of Synthetic Aperture Radar (SAR) imagery would represent a keystone to realize almost continuous global monitoring of plastic litter at sea, but robust and reliable approaches for SAR-based plastic detection at sea are not available. The main problem is the lack of a large and assessed dataset to train and test new procedures and methods (e.g., deep learning) on large scales. Starting from this point, CROSSEYE (Combined in pendulum Remote Observation cubeSat System for icEYE) mission is presented with the objective to generate a wide dataset of multi-spectral and SAR images collected at the same time over the same areas. Plastic detection in multi-spectral images is mature enough to be used as a ground truth to cue SAR-based algorithms that autonomously perform the same task. CROSSEYE exploits a pre-existing SAR satellite belonging to ICEYE constellation - ICEYE-X16 - and completes it with an additional multi-spectral camera equipped on a 6U CubeSat. The results coming from the preliminary design of CROSSEYE demonstrate the feasibility of a mission capable of detecting plastic debris from space by using state-of-the-art technologies.
Development of a smart docking system for small satellites
Authors: Caon A.
Published: October 2023

Abstract. DOCKS is a smart docking system for space vehicles developed by the Department of Industrial Engineering, University of Padova, within the framework of the Space Rider Observer Cube (SROC) mission. The design and development of SROC is being conducted by a consortium of Italian entities under contract with the European Space Agency (ESA). The SROC mission is designed to be a payload on the ESA Space Rider (SR) spaceship. The main objective of the mission is to demonstrate the critical capabilities and technologies required to execute a rendezvous and docking mission in a safety-sensitive context. The space system is composed by a nanosatellite (approximately 12U CubeSat) and a deployment/retrieval mechanism mounted inside the payload bay of SR. During the mission, SROC will be released by SR, will perform inspection manoeuvres on SR and, at the end of the mission, will dock back inside the bay of SR, before re-entering Earth with the mothership. The docking functionality is provided by DOCKS. DOCKS is suitable for use onboard micro- and nanosatellites and merges a classical probe drogue configuration with a gripper–like design, to manage the connection between the parts. The system is equipped with a suite of sensors to estimate the relative pose of the target and with a dedicated computer, making it a smart standalone system. A laboratory prototype has been assembled and functionally tested, aiming at the validation of the capability to passively manage misalignments during the docking manoeuvre.
Analysis of small spacecraft Mars aerocapture through a single-event drag modulation
Authors: La Marca T.A.
Published: October 2023

Abstract. In the last years, the scientific interest in Mars exploration has become more and more relevant, driving the development of technologies aimed at improving the current capabilities to land scientific payloads or to insert probes into stable orbits around the planet. In this framework, the use of low-cost small satellites could represent an advantageous solution for both the mission scenarios. In planetary exploration, the aerocapture manoeuvre is considered a promising technique to overcome the limits imposed by specific volume and mass ratio constraints on the design of the propulsion system. Based on these premises, this work focuses on the 2D aerocapture manoeuvre of a small spacecraft equipped with a Deployable Heat Shield (DHS). Specifically, the analysis aims at assessing the aerocapture manoeuvre feasibility exploiting a single shield surface variation.
Mechanical and pneumatic design and testing of a floating module for zero-gravity motion simulation
Authors: Galleani S.
Published: October 2023

Abstract Close proximity operations demand an accurate control in a micro-gravity environment, hence they must be reproduced and simulated systematically. Consequently, laboratory tests are a crucial aspect to validate the performances of space systems. This paper presents the development of a floating pneumatic module, whose dimensions and mass are representative of a 12U CubeSat. The vehicle has been designed to perform planar low friction motion over a levelled table for docking experiments. The paper focuses on the pneumatic and mechanical designs and on the laboratory tests of the module. The pneumatic design regards the air-compressed pneumatic system. The major specifics have been determined by the requirement of performing a docking procedure by starting from a distance of 500 mm. The mechanical design has been guided by two main requirements. The first is the possibility to accommodate different docking systems (e.g.: docking port). The second is the possibility to control the position of the centre of mass of the module. Several tests have been performed to verify the capabilities of the vehicle, such as: (1) pneumatic tests to evaluate the thrust of the propulsion system through the execution of linear motions and (2) mechanical measurements with dedicated setups to improve the estimation of the position of the centre of mass from the CAD model of the system.
Deployment profile analysis for tethered deorbiting technologies
Authors: Polato G.
Published: October 2023

Abstract. Over the past few decades, the man-made space debris has become an increasingly concerning problem for future space missions. Fortunately, some innovative "green" deorbiting technologies have been emerged. Among these strategies, electrodynamic tethers have demonstrated to be a promising option, thanks to their passive and fuel-free characteristics. By leveraging the Earth's ionosphere and the geomagnetic field, an electrodynamic tether generates a Lorentz drag force, that can significantly reduce the altitude of a satellite and ultimately cause it to re-enter the atmosphere. The goal of this research is to investigate a critical part of satellite tethered technology, namely the deployment phase. To accomplish this, we utilized a software tool developed by the University of Padova to simulate the dynamics of the deployment phase and optimize its trajectory, in order to meet the desired boundary conditions. This paper gives a description of the software and shows the results of a sensitivity analysis on the trajectory profile that examines the impact of variations in the release angle of the tether and the speed profile actuated by the motor that controls the deployment speed.
Near-optimal feedback guidance for low-thrust earth orbit transfers
Authors: Pontani M.
Published: October 2023

Abstract. This research proposes a near-optimal feedback guidance based on nonlinear control for low-thrust Earth orbit transfers. For the numerical simulations, two flight conditions are defined: (i) nominal conditions and (ii) nonnominal conditions that account for the orbit injection errors and the stochastic failures of the propulsion system. Condition (ii) is studied through an extensive Monte Carlo Analysis, to demonstrate the nonlinear feedback guidance’s numerical stability and convergence properties. To illustrate the performance under both conditions, an orbit transfer from low Earth orbit to geostationary orbit is considered. Near-optimality of the feedback guidance comes from carefully selecting the nonlinear control gains. Comparison of the transfer with an existing study that uses optimal control reveals that orbit transfers based on feedback orbit control are very close to the optimal solution.
Vibro-acoustic analysis of additively manufactured acoustic metamaterial via CUF adaptive finite elements
Authors: Rossi M.
Published: October 2023

Abstract. In the field of noise and vibrations control inside the cabin, passive noise solutions coupled with the development of new unconventional materials, called Acoustic Metamaterials (AMMs) can be very promising to stop incoming noise and guarantee the passenger’s comfort without an increase in aircraft weight. Within the framework of Carrera’s Unified Formulation (CUF), we study the acoustic properties of double pierced AMM plate printed with Fused deposition modelling technique (FDM). The influence of several geometrical parameters is investigated, such as the size and location of the holes and the perforation ratio. The properties of this AMM are derived from vibro-acoustic analyses of the finite element software, Mul2, developed by Politecnico di Torino, that exploits the CUF. In order to study the AMM complex structure in the CUF framework, the Adaptive finite elements are exploited. This new class of 2D elements, recently developed, allows us to model with shell elements the AMM structure, which presents several discontinuities in the mid-surface due to the presence of corners and internal cavities.
A brief review of pilots’ workload assessment using flight simulators: subjective and objective metrics
Authors: Iacolino G.
Published: October 2023

Abstract. This study explores subjective and objective metrics to assess pilots WL, with a particular focus on the use of full flight simulators (FFS). The results show that FFS-based research demonstrates no significant differences compared to real flight experiences, highlighting the validity of FFS as a tool for studying pilots' performance. However, further research is needed to understand the impact of other parameters on pilots' performance, and to address human factor-related risks for enhanced aviation safety.
Applying an interior VR co-design approach for the medical deployment vehicle of the future
Authors: Herzig J.
Published: October 2023

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Innovative ideas for the use of augmented reality devices in aerodrome control towers
Authors: Teutsch J.
Published: October 2023

Abstract. In recent years Augmented Reality (AR) has become one of the major focus points of user interface development. With the rapidly increasing computing power and developments in software and hardware applications during the last two decades, it has moved from theoretical approaches towards industry-wide application and mass production. The Royal Netherlands Aerospace Centre, NLR, tested several devices in the past, but only recent developments made it possible to effectively use them in an Air Traffic Control (ATC) working environment for Aerodrome Control Towers. In 2021 NLR carried out innovative technology experiments on their high-fidelity real-time air traffic control simulation and validation platform, NARSIM. These experiments were part of the SESAR 2020 project Digital Technologies for Tower (DTT) and focused on advanced HMI interaction modes for aerodrome tower controllers. A proposed Attention Capturing and Guidance concept with an AR device was evaluated inside an aerodrome control tower environment for Amsterdam Airport Schiphol. This paper reflects on the technology development activities that took place at NLR during the last decade and describes the different steps taken to apply the technology in a conventional control tower environment. It is shown that the recent technology developments must be seen as a big step forward in practical application of AR devices for ATC. Furthermore, an outlook into the expected future use of AR devices in conventional control tower environments will be given that goes beyond abovementioned concept elements. This outlook considers additional developments for standardization of digitized airport information and communication between different stakeholders and general performance improvements for AR devices.
Maturity-based taxonomy of extended reality technologies in aircraft lifecycle
Authors: Bagassi S.
Published: October 2023

Abstract. EXtended Reality (XR) is a fast growing and rapidly evolving technology. In the aeronautical sector, XR can be exploited for the entire aircraft lifecycle, however, different levels of maturity can be identified for applications in each one of the lifecycle’s phases. This paper, by outlining the TRL of current XR applications over the aircraft lifecycle, aims to be a foundation to identify the possible future improvements and applications of immersive technologies in the aeronautical sector.
Experiments and simulations for the development of a dual-stator PMSM for lightweight fixed-wing UAV propulsion
Authors: Suti A.
Published: October 2023

Abstract. The work summarizes the experimental and simulation studies carried out on the full-electric propulsion system of a lightweight fixed-wing UAV developed in the research program TERSA. The electric motor, specifically designed for the project, is a double-stator axial-flux PMSM with single output shaft, directly connected to a twin-blade fixed-pitch propeller. The system dynamics is firstly addressed by nonlinear simulation, modelling the motor and related sensors, the propeller and the digital controllers, to design the closed-loop control architecture. Successively, an experimental campaign is defined to identify/substantiate the main motor parameters (resistance and inductance of phases, torque and speed constants, back-electromotive force waveforms) and to validate the closed-loop control design.