bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Computer Vision Systems and Applications to Estimate Trunk Cross-Sectional Area, Flower Cluster Number, Thinning Efficacy and Yield of Apple
Authors: Gonzalez Nieto Luis , Wallis Anna , Clements Jon , Miranda Sazo Mario , Kahlke Craig , Kon Thomas M. , Robinson Terence L.
Published: August 2023

Precision crop load management of apple requires counting fruiting structures at various times during the year to guide management decisions. The objective of the current study was to evaluate the accuracy of and compare different commercial computer vision systems and computer applications to estimate trunk cross-sectional area (TCSA), flower cluster number, thinning efficacy, and yield estimation. These studies evaluated two companies that offer different vision systems in a series of trials across 23 orchards in four states. Orchard Robotics uses a proprietary camera system, and Pometa (previously Farm Vision) uses a cell phone camera system. The cultivars used in the trials were ‘NY1’, ‘NY2’, ‘Empire’, ‘Granny Smith’, ‘Gala’, ‘Fuji’, and ‘Honeycrisp’. TCSA and flowering were evaluated with the Orchard Robotics camera in full rows. Flowering, fruit set, and yield estimation were evaluated with Pometa. Both systems were compared with manual measurements. Our results showed a positive linear correlation between the TCSA with the Orchard Robotics vision system and manual measurements, but the vision system underestimated the TCSA in comparison with the manual measurements (R2s between 0.5 and 0.79). Both vision systems showed a positive linear correlation between nubers of flowers and manual counts (R2s between 0.5 and 0.95). Thinning efficacy predictions (in June) were evaluated using the fruit growth rate model, by comparing manual measurements and the MaluSim computer app with the computer vision system of Pometa. Both systems showed accurate predictions when the numbers of fruits at harvest were lower than 200 fruit/tree, but our results suggest that, when the numbers of fruits at harvest were higher than 200 fruit/tree, both methods overestimated final fruit numbers per tree when compared with final fruit numbers at harvest (R2s 0.67 with both systems). Yield estimation was evaluated just before harvest (August) with the Pometa system. Yield estimation was accurate when fruit numbers were fewer than 75 fruit per tree, but, when the numbers of fruit at harvest were higher than 75 fruit per tree, the Pometa vision system underestimated the final yield (R2 = 0.67). Our results concluded that the Pometa system using a smartphone offered advantages such as low cost, quick access, simple operation, and accurate precision. The Orchard Robotics vision system with an advanced camera system provided more detailed and accurate information in terms of geo-referenced information for individual trees. Both vision systems evaluated are still in early development and have the potential to provide important information for orchard managers to improve crop load management decisions.
Voices from the Margins: Aotearoa/New Zealand Young Carers Reflect on Their Experiences
Authors: Donnan Lauren , Gaffney Janet S. , Bruce Toni
Published: August 2023

Young carers are a largely invisible and unsupported population of Aotearoa New Zealand (NZ) children and youth aged 25 years and under who physically, emotionally, socially, and/or spiritually support loved ones experiencing ill health, disability, substance misuse, mental illness, or advanced age. The total number of young carers in NZ is unknown because census data only capture those aged 15–25. The nine published NZ studies recommend further research, policies, and services for young carers. However, there is a lack of young carer voices to inform their implementation. This paper provides insight into the experiences and needs of 28 young carers, the largest self-identified cohort in NZ research. Throughout phenomenographic interviews, young caring was described as a natural and valued part of being in a whānau/aiga/family, aimed at supporting their loved one’s holistic wellbeing. However, the overwhelming nature of caring without recognition or support resulted in poor educational, social, and mental health outcomes for young carers. This paper concludes with a contextualised NZ young carer definition and an urgent call to address the Carers’ Strategy Action Plan and listen to, and deliver on, young carers’ expressed needs.
Adaptive Coping Strategies at the Time of COVID-19: The Role of Social and General Trust
Authors: Graziani Anna Rita , Botindari Lucia , Menegatti Michela , Moscatelli Silvia
Published: August 2023

Research in the field shows the crucial role of trust in the functioning of many aspects of social life, especially when dealing with emergencies. We report the results of a study (N = 883) carried out in Italy during the first phase of the COVID-19 crisis to assess whether and how social trust (i.e., trust in those who have the authority and responsibility for making decisions, such as the Italian government, the regional government, the Civil Protection, the European Union, the Catholic Church, and the scientific community) and general trust (i.e., trust in the trustworthiness of other individuals, such as Italians and humankind) are associated with the employment of coping strategies in dealing with the challenges of the pandemic. Overall, the results highlight that trust in different authorities and institutions and trust in other human beings are positively associated with the adoption of adaptive coping strategies such as seeking social support, positive reinterpretation and growth, problem-solving orientation, and transcendent orientation. In contrast, they are negatively related to the adoption of maladaptive coping strategies such as avoidance. These findings point out the benefits of various types of trust in helping individuals deal with crises, such as the COVID-19 pandemic.
Physical Activity in Long COVID: A Comparative Study of Exercise Rehabilitation Benefits in Patients with Long COVID, Coronary Artery Disease and Fibromyalgia
Authors: Colas Claire , Le Berre Yann , Fanget Marie , Savall Angélique , Killian Martin , Goujon Ivan , Labeix Pierre , Bayle Manon , Féasson Léonard , Roche Frederic , Hupin David
Published: August 2023

Exercise in long COVID is poorly studied. Nevertheless, exerciserehabilitation could improve cardiorespiratory, muscular and autonomic functions. We aimed to investigate improvement in physical and autonomic performances of long COVID patients (n = 38) after a 4-week exercise rehabilitation program (3 sessions/week) compared to two control groups composed of coronary artery disease (n = 38) and fibromyalgia patients (n = 38), two populations for whom exercise benefits are well known. Efficacy of exercise training was assessed by a cardiopulmonary exercise test, a handgrip force test, and a supine heart rate variability recording at rest before and after the rehabilitation program. Cardiorespiratory and muscular parameters were enhanced after exercise rehabilitation in the three groups (p < 0.001). No significant difference was observed for the autonomic variables. Through this comparative study with control groups, we confirm and reinforce the interest of caring for long COVID patients without post-exertional symptom exacerbation by exercise rehabilitation of both strength and endurance training, by personalizing the program to the patient and symptoms.
Does Decreased Diffusing Capacity of the Lungs for Carbon Monoxide Constitute a Risk of Decompression Sickness in Occupational Divers?
Authors: Loddé Brice , Giroux-Metges Marie-Agnès , Galinat Hubert , Kerspern Hèlène , Pougnet Richard , Saliou Philippe , Guerrero François , Lafère Pierre
Published: August 2023

Long-term alterations of pulmonary function (mainly decreased airway conductance and capacity of the lungs to diffuse carbon monoxide (DLCO)) have been described after hyperbaric exposures. However, whether these alterations convey a higher risk for divers’ safety has never been investigated before. The purpose of the present pilot study was to assess whether decreased DLCO is associated with modifications of the physiological response to diving. In this case–control observational study, 15 “fit-to-dive” occupational divers were split into two groups according to their DLCO measurements compared to references values, either normal (control) or reduced (DLCO group). After a standardized 20 m/40 min dive in a sea water pool, the peak-flow, vascular gas emboli (VGE) grade, micro-circulatory reactivity, inflammatory biomarkers, thrombotic factors, and plasmatic aldosterone concentration were assessed at different times post-dive. Although VGE were recorded in all divers, no cases of decompression sickness (DCS) occurred. Compared to the control, the latency to VGE peak was increased in the DLCO group (60 vs. 30 min) along with a higher maximal VGE grade (p < 0.0001). P-selectin was higher in the DLCO group, both pre- and post-dive. The plasmatic aldosterone concentration was significantly decreased in the control group (−30.4 ± 24.6%) but not in the DLCO group. Apart from a state of hypocoagulability in all divers, other measured parameters remained unchanged. Our results suggest that divers with decreased DLCO might have a higher risk of DCS. Further studies are required to confirm these preliminary results.
Telerehabilitation in the Finnish Outpatient Rehabilitation Setting from the Perspective of the Socio-Technical Systems Theory
Authors: Partanen Tuija , Seppänen-Järvelä Riitta , Hiekkala Sinikka , Lindh Jari
Published: August 2023

Background: In the development of effective telerehabilitation (TR) interventions, understanding the various characteristics affecting its practice is essential. Remote connection creates a new technically shaped environment for therapy and, therefore, previous therapy methods do not work the same way as before. Objective: The objective of this survey was to describe the practice of TR through the socio-technical theory approach. Methods: The 629 respondents to the online questionnaire included music therapists, occupational therapists, speech and language therapists, physiotherapists, and neuropsychologists. The materials consisted of five open-ended questions. The analysis combined data-based and theory-based analysis. Results: In the data-based content analysis, we identified three main categories and eight generic categories, whereas in the theory-based, we categorised the main results according to the Fit Between Individuals, Tasks, Technology, and Environment (FITTE) framework dimensions. TR is everyday-life based, it requires shared participation, and the approach has to include coaching and collaboration with the client and their close associates. The everyday-life environment is one of the main dimensions that affect all the other dimensions. Conclusions: TR can be seen as technology-mediated home-based rehabilitation, as it can integrate rehabilitation into the client’s everyday life. In TR, therapy becomes multilateral and it creates a new kind of shared partnership into outpatient therapy.
Effect of Vitamin E on Transcriptomic Alterations in Alzheimer’s Disease
Authors: Ekeuku Sophia Ogechi , Mohd Murshid Nuraqila , Shukri Siti Nursyazwani , Mohd Sahardi Nur Fatin Nabilah , Makpol Suzana
Published: August 2023

Research into ageing is focused on understanding why some people can maintain cognitive ability and others lose autonomy, affecting their quality of life. Studies have revealed that age-related neurodegenerative disorders like Alzheimer’s disease (AD) are now major causes of death among the elderly, surpassing malignancy. This review examines the effects of vitamin E on transcriptomic changes in ageing and neurodegenerative diseases, using AD as an example, and how different transcriptome profiling techniques can shape the results. Despite mixed results from transcriptomic studies on AD patients’ brains, we think advanced technologies could offer a more detailed and accurate tool for such analysis. Research has also demonstrated the role of antioxidant modifiers in preventing AD. This review will explore the key findings regarding AD and its modulation by vitamin E, emphasizing the shift in its epidemiology during the ageing process.
Adipose Tissue-Derived Products May Present Inflammatory Properties That Affect Chondrocytes and Synoviocytes from Patients with Knee Osteoarthritis
Authors: Cavallo Carola , Boffa Angelo , Salerno Manuela , Merli Giulia , Grigolo Brunella , Filardo Giuseppe
Published: August 2023

Adipose tissue-derived cell-based injectable therapies have been demonstrated to have disease-modifying effects on joint tissues in preclinical studies on animal osteoarthritis (OA) models, but clinical results are heterogeneous and not always satisfactory. The aim of this study was to investigate the influence of adipose tissue properties on the therapeutic effects of the adipose-derived product in an in vitro OA setting. Micro-fragmented adipose tissue (MF-AT) samples were obtained from 21 OA patients (mean age 51.7 ± 11.8 years, mean BMI 25.7 ± 4.1 kg/m2). The analysis of the MF-AT supernatant was performed to analyze the release of inflammatory factors. The effects of MF-AT inflammatory factors were investigated on chondrocytes and synoviocytes gene expression levels. Patients’ characteristics were analyzed to explore their influence on MF-AT inflammatory molecules and on the MF-AT effects on the gene expression of chondrocytes and synoviocytes. The study results demonstrated that adipose tissue-derived products may present inflammatory properties that influence the therapeutic potential for OA treatment, with products with a higher pro-inflammatory profile stimulating a higher expression of genes related to a more inflamed and catabolic phenotype. A higher pro-inflammatory cytokine pattern and a higher pro-inflammatory effect were found in adipose tissue-derived products obtained from OA patients with higher BMI.
An Evaluation of Feature Selection Robustness on Class Noisy Data
Authors: Pau Simone , Perniciano Alessandra , Pes Barbara , Rubattu Dario
Published: August 2023

With the increasing growth of data dimensionality, feature selection has become a crucial step in a variety of machine learning and data mining applications. In fact, it allows identifying the most important attributes of the task at hand, improving the efficiency, interpretability, and final performance of the induced models. In recent literature, several studies have examined the strengths and weaknesses of the available feature selection methods from different points of view. Still, little work has been performed to investigate how sensitive they are to the presence of noisy instances in the input data. This is the specific field in which our work wants to make a contribution. Indeed, since noise is arguably inevitable in several application scenarios, it would be important to understand the extent to which the different selection heuristics can be affected by noise, in particular class noise (which is more harmful in supervised learning tasks). Such an evaluation may be especially important in the context of class-imbalanced problems, where any perturbation in the set of training records can strongly affect the final selection outcome. In this regard, we provide here a two-fold contribution by presenting (i) a general methodology to evaluate feature selection robustness on class noisy data and (ii) an experimental study that involves different selection methods, both univariate and multivariate. The experiments have been conducted on eight high-dimensional datasets chosen to be representative of different real-world domains, with interesting insights into the intrinsic degree of robustness of the considered selection approaches.
Machinability of Titanium Grade 5 Alloy for Wire Electrical Discharge Machining Using a Hybrid Learning Algorithm
Authors: Natarajan Manikandan , Pasupuleti Thejasree , Giri Jayant , Sunheriya Neeraj , Katta Lakshmi Narasimhamu , Chadge Rajkumar , Mahatme Chetan , Giri Pallavi , Mallik Saurav , Ray Kanad
Published: August 2023

Titanium alloys have found widespread use in aviation, automotive, and marine applications, which makes their implementation in mass production more challenging. Conventional methods of removing these alloy materials are unsuitable because of the high wear rate of cutting and slower rate of processing. The complexities of these materials have prompted the creation of cutting-edge machining methods. Wire Electrical Discharge Machining (WEDM) is a technique that has the potential to be useful for the removal of materials that are harder and electrically conductive. In order to create intricate designs, this method is frequently employed. The input factors, including pulse duration (on/off) and peak current, were taken into account during the experimental design process. The rate of material removal, surface roughness, dimensional deviation, and GD&T errors were opted for as performance indicators. The approach proposed by Taguchi was selected for the investigation of the process factors, and an Analysis of Variance was selected to find out the relative momentousness of each factor. From the analysis it is perceived that the applied current is the predominant factor that influences the chosen output characteristics. The aspiration of this article is to evolve a decision-making model based on a hybrid learning method which can be adopted to predict the selected output measures that affect the WEDM process. According to the findings, the value of the ANFIS-GRG, which was predicted to be 0.7777, was in fact closer to that value than any other value. The proposed model has the ability to help make a variety of different production processes more efficient. The analysis showed that the model’s functionality was enhanced, which helps producers make well-informed decisions.
Barriers to gBRCA Testing in High-Risk HER2-Negative Early Breast Cancer
Authors: Foroughi Olivia , Madraswala Shaheen , Hayes Jennifer , Glover Kara , Lee Liam , Chaki Moumita , Redpath Stella , Yu Agnes Weixuan , Chiu David , Amanti Kristen Garner , Gustavsen Gary
Published: August 2023

Despite the OlympiA trial demonstrating that early-stage, high-risk, HER2- germline BRCA1 and BRCA2 mutation (gBRCAm) positive breast cancer patients can benefit from PARPi in the adjuvant setting, the gBRCA testing rate in early-stage HR+/HER2− patients remains suboptimal compared to that in early-stage TNBC patients. To better understand the perceived barriers associated with gBRCA testing in HR+/HER2− disease, a quantitative survey was conducted across stakeholders (n = 430) including medical oncologists, surgeons, nurses, physician assistants, payers, and patients. This study revealed that while payers claim to cover gBRCA testing, poor clinician documentation and overutilization are key challenges. Therefore, payers place utilization management controls on gBRCA testing due to their impression that clinicians overtest. These controls have led to healthcare professionals experiencing payer pushback in the form of reimbursement limitations and denials. The perceived challenges to gBRCA testing stem from the lack of consensus dictating which patients are high risk and should be tested. While payers define high risk based on the CPS + EG score from the OlympiA trial, HCPs adopt a broader definition including genomic risk scores, lymph node involvement, and tumor grade and size. A dialogue to harmonize risk classification and testing eligibility across stakeholders is critical to address this disconnect and increase gBRCA testing in appropriate patients.
Feasibility of a Virtual-Reality-Enabled At-Home Telerehabilitation Program for Stroke Survivors: A Case Study
Authors: Choukou Mohamed-Amine , He Elizabeth , Moslenko Kelly
Published: August 2023

Stroke rehabilitation is a lengthy procedure that is necessary for stroke recovery. However, stroke rehabilitation may not be readily available for patients who live rurally due to barriers such as transportation and expenses. This shortage in wearable technology, in turn, causes health disparity among the rural population, which was exacerbated by the COVID-19 pandemic restrictions. Telerehabilitation (TR) is a potential solution for stroke rehabilitation in rural areas. This one-case study aimed to examine the feasibility and safety of a technology-enabled at-home TR program for stroke survivors living in a rural area in Canada. A VR setup was installed successfully in the home of our participant. A tablet was also supplied for the TR program. Each program consisted of 24 sessions to be completed over a 12-week period. Our participant was assessed on day one using the Fugl-Meyer assessment, the Modified Ashworth Scale, the 10 m walk test, and the Mini-Mental State Exam. Three questionnaires were also completed, including the Motor Activity Log (MAL), the Stroke Index Scale (SIS), and the Treatment Self-Regulation Questionnaire. These assessments were completed thrice, on day 1, at week 6, and at week 12. The participant found the tablet and its accompanying exercises easy to use, with a few limitations. The participant found the VR system more challenging to manage independently as a lack of comfortability, the visual contrast during the first trials, and certain technical aspects of the technology created several functional barriers. Although some limitations with the technology were noted, this case study indicates that telerehabilitation is feasible under certain circumstances when used in conjunction with traditional rehabilitation services.
Assessment of Risk Factors and the Relationship between Hypothyroidism with Hypertension in Diabetes Mellitus Patients: A Cross-Sectional Community-Based Study
Authors: Shaphe Mohammad Abu , Alshehri Mohammed M. , Alfaifi Bushra , Aljahni Mohammed A , Esht Vandana , Malik Shazia , Bautista Marissa J , Alqahtani Abdulfattah S. , Ahmad Ausaf , Khan Ashfaque , Aafreen Aafreen , Khan Abdur Raheem
Published: August 2023

(1) Background: hypertension (HTN) and diabetes mellitus (DM) represent two widely noncommunicable diseases that are prevalent globally, and they often correlate with chronic health issues. There has been an acknowledged connection between diabetes, hypertension, and hypothyroidism for quite some time. However, the extent of thyroid dysfunction among the diabetic population is not uniform and significantly differs across different research studies. This study was conducted with the objective of identifying the risk factors associated with hypothyroidism as well as assessing the relationship between hypothyroidism and hypertension in patients with diabetes. (2) Materials and Methods: Participants aged 18 years and above were included in this study, while pregnant women were excluded. Trained health professionals measured sociodemographic, behavioural, food practices, and anthropometric information about the participants. Each respondent sought medical advice regarding their health, and a face-to-face interview enabled them to express concern about the likelihood of being diagnosed with diabetes mellitus and hypertension. (3) Results: The study encompassed 640 participants, with an average age of 49.20 ± 13.0 years. Among these participants, 65.5% were female, and 34.5% were male. Of the total, 31.25% were diagnosed with diabetes mellitus, and 18.75% had hypertension. Interestingly, co-occurrence of both conditions was observed in 9.68% of the population. A comparison of thyroid function and indicators of blood sugar levels yielded consistent results across the different patient groups. Specifically, for diabetes mellitus (DM) patients, the average levels were 3.4 ± 9.8 pg/mL for fT3, 0.9 ± 0.7 ng/dL for fT4, 3.3 ± 6.2 μiU/mL for TSH, 153.1 ± 68.0 mg/dL for fasting plasma glucose (FPG), 213.2 ± 97.2 mg/dL for postprandial glucose (PPG), and 8.3 ± 3.2% for HbA1c. (4) Conclusion: It is concluded that patients with hypertension had a significant prevalence of diabetes mellitus. Subclinical hypothyroid subjects must be frequently screened for hypertension. Of 120 individuals with hypertension, 45 (37.5%) were also diagnosed with diabetes. This co-occurrence was significantly higher in subjects aged over 50 years (26.7%), in the lower socio-economic class (18.5%), and among those who were married (14.7%). Additionally, patients with hypertension exhibited a high prevalence of diabetes across different educational backgrounds and occupations, with the highest prevalence among postgraduates (37.5%) and professionals (24.0%), respectively. These findings highlight the need for an integrated approach to the management of hypertension and diabetes, particularly in high-risk demographics.
Effects of Heat Treatment on Microstructure and Mechanical Properties of Weldable Al–Mg–Zn–Sc Alloy with High Strength and Ductility
Authors: Jiang Long , Zhang Zhifeng , Bai Yuelong , Mao Weimin
Published: August 2023

A weldable Al–Mg–Zn–Sc alloy was produced using vacuum induction melting and an argon-protected casting method to achieve high strength and ductility, and the effects of heat treatment on the microstructure evolution and mechanical properties of Al–Mg–Zn–Sc alloys were comparatively investigated. The results reveal that fine equiaxed grains with an average grain size of 40 μm in an as-cast Al–Mg–Zn–Sc alloy change little after heat treatments, bringing about a grain-boundary strengthening of 46.1 MPa. The coarse T-Mg32(Al, Zn)49 phases at grain boundaries are completely dissolved into the matrix through solid-solution treatment, and T-Mg32(Al, Zn)49 with diameters ranging from 10 to 25 nm and Al3Sc with diameters ranging from 5 to 20 nm gradually precipitate during the artificial aging process. The Mg solid solubility is 4.67% in the as-cast Al–Mg–Zn–Sc alloy, and it increased to 5.33% after solid-solution treatment and dramatically decreased to 4.15% after post-aging treatment. The contributions of solid-solution strengthening to as-cast, post-solid-solution and post-aging Al–Mg–Zn–Sc alloys are 78.2 MPa, 85.4 MPa and 72.3 MPa, respectively. The precipitation strengthening of the post-aging alloy is 49.7 MPa, which is an increase of 21% in comparison to that of both as-cast and post-solid-solution alloys. The alloy achieves an optimal tensile strength of 355.3 MPa, yield strength of 175 MPa and elongation of 22% after undergoing solid-solution treatment.
Microstructural Evolution and Micro-Corrosion Behaviour of Flash-Welded U71Mn Joints as a Function of Post-Weld Heat Treatment
Authors: Liao Tingting , Zhang Xi , Yang He , Zhou Pan , Chen Fei
Published: August 2023

The microstructural evolution and corrosion behaviour of railroad flash-butt-welded U71Mn joints and the effect of heat treatment were investigated via scanning electron microscopy and electrochemical measurements. The joint structures were found to mainly comprise pearlite and a few ferrites. The grains became finer and more homogeneous after heat treatment. Additionally, there was a decrease in the corrosion current density (1.71 × 10−5 A cm−2) and increases in the absolute corrosion potential (0.86 mV) and corrosion resistance (1088.83 Ω−1cm2). This was primarily attributed to the fewer Cl− ions at the homogeneous grain boundaries and fewer oxidation reactions on the joints after heat treatment. The findings of this study explain corrosion failure and will guide the development of corrosion-resistant joints for improved railroad quality.
Triboelectric Nanogenerator for Droplet Energy Harvesting Based on Hydrophobic Composites
Authors: Zheng Yang , Li Jingjing , Xu Tiantian , Cui Hongzhi , Li Xiaoyi
Published: August 2023

Triboelectric nanogenerators (TENG) have shown great potential in harvesting energy from water. For the TENG that harvests water energy, surface hydrophobicity is crucial for its performance. In this paper, we prepare a hydrophobic composite film of Polyvinylidene Fluoride/Polydimethylsiloxane/Polytetrafluoroethylene (PVDF/PDMS/PTFE) and an electrode of Polyaniline/Carbon nanotubes/Silver nanowires (PANI/CNTs/AgNWs) by electrospinning technology and a doping method, respectively, which are served as the friction layer and top electrode of TENG. The contact angle of the hydrophobic film and electrode both reach over 120°, which makes the separation process between water and the interface complete and promotes the output of TENG. The open-circuit voltage (Voc) and short-circuit current (Isc) can reach 150 V and 60 μA approximately. In addition, the composite electrode can be applied in the preparation of complex electrode shapes. Furthermore, the different reactions of TENG to different liquids indicate that it may contribute to liquid-type sensing systems. This work presents an efficient approach to fabricating hydrophobic films and electrodes, laying a foundation for the development of TENG for harvesting water energy.
Experimental Investigation into the Influence of the Process Parameters of Wire Electric Discharge Machining Using Nimonic-263 Superalloy
Authors: Dereje Teshome , Palani Sivaprakasam , Desta Melaku , Čep Robert
Published: August 2023

Nimonic alloy is difficult to machine using traditional metal cutting techniques because of the high cutting forces required, poor surface integrity, and tool wear. Wire electrical discharge machining (WEDM) is used in a number of sectors to precisely machine complex forms of nickel-based alloy in order to attempt to overcome these challenges and provide high-quality products. The Taguchi-based design of experiments is utilized in this study to conduct the tests and analyses. The gap voltage (GV), pulse-on time (Ton), pulse-off time (Toff), and wire feed (WF), are considered as the variable process factors. GRA is used for the WEDM process optimization for the Nimonic-263 superalloy, which has multiple performance qualities including the material removal rate (MRR), surface roughness (SR), and kerf width (KW). ANOVA analysis was conducted to determine the factors’ importance and influence on the output variables. Multi objective optimization techniques were employed for assessing the machining performances of WEDM using GRA. The ideal input parameter combinations were determined to be a gap voltage (GV) of 40 V, a pulse-on time (Ton) of 8 µs, a pulse-off time (Toff) of 16 µs, and a wire feed (WF) of 4 m/min. A material removal rate of 8.238 mm3/min, surface roughness of 2.83 µm, and kerf width of 0.343 mm were obtained. The validation experiments conducted also demonstrated that the predicted and experimental values could accurately forecast the responses.
Modular UV Curing Sol-Gel Coating for Invisible, Levelling and Easy to Clean Multi-Layer Systems
Authors: Rico Lucía Florentino , Conejero Iglesias Olga , de la Rua García Ramón Bernardo , Moriones Domeño Jennifer , Fernández de Ara Jonathan , Fuentes Gonzalo G.
Published: August 2023

Current methods for the hardening step of functional coatings over different materials imply the use of high temperatures, high energy consumption or long periods of time, which have repercussions on the speed and cost of the product. We report here a simple and low-cost methodology for the functionalization of low-cost stainless steel, which is modular, depending on the functionality pursued: a levelling layer for smoothing the surface of the material, an “easy to clean” property, or both of them. This research is based on sol-gel coatings cured under UV light without requiring high thermal hardening processes, making it applicable to plastics and other sensible materials and possessing high chemical and thermal stability. The film ensures lower processing costs and higher rates of hardening if adequate medium-pressure lamps are employed. This formulation is also well-defined for scaling up the process, so it is possible to perform a continuous coating in large areas by employing mild processing conditions (low temperature, atmospheric pressure). In addition, the sol-gel solution was fully characterized and studied in order to guarantee a long service life before deposition, with a focus on industrial applications in the domestic sector.
Effects of Twisting and Surface Finish on the Mechanical Properties of Natural Gut Harp Strings
Authors: Lynch-Aird Nicolas , Woodhouse Jim
Published: August 2023

Natural gut harp strings are made from twisted bundles of gut strips, which are dried, ground, and varnished. The effects of varying the twist angle and surface finishing on the mechanical properties of gut harp strings have been explored. Strings were tested over a range of twist angles from 23.5∘ to 58.3∘, and with all four combinations of ground or unground and varnished or unvarnished surface finishing. The principal effects of varying the degree of twisting were that the breaking strength and tensile Young’s modulus both fell as the twist angle was increased. String makers must therefore make a compromise between sound quality and string strength and durability. Leaving the string unvarnished dramatically increased the sensitivity to changes in humidity, which, in turn, affected the thermal tuning sensitivity and creep behaviour. Grinding the string surface prior to varnishing had no significant effect on the behaviour, but did make some difference to the thermal tuning sensitivity if the string was left unvarnished. Increasing the humidity frequently triggered episodes of additional string creep. There appeared to be a threshold effect, with the additional creep triggered when the string linear density exceeded its previous maximum. When the string was not creeping, there appeared to be a strong coupling mechanism between changes in the linear density and complementary changes in the string tension, such that there was almost no net effect on the string frequency. This behaviour was independent of the twist angle and the surface finishing, suggesting that whatever the coupling mechanism was, it was not dependent on the twisted structure of the string.
Effect of Cu as a Minority Alloying Element on the Corrosion Behaviour of Amorphous and Crystalline Al-Ni-Si Alloy
Authors: Dyakova Vanya , Kostova Yoanna , Tzaneva Boriana , Spasova Hristina , Kovacheva Daniela
Published: August 2023

The effect of copper as a minority alloying element on the corrosion behaviour of amorphous and crystalline Al74Ni16Si10 and Al74Ni15Si9Cu2 alloys was investigated in this study. Amorphous alloys were produced as rapidly solidified ribbons using the Chill Block Melt Spinning (CBMS) method and subsequently annealed to complete crystallisation. The corrosion rate of alloys was obtained through continuous immersion tests in 3.5% NaCl at 25 °C and 50 °C for 360 h. The electrochemical parameters corrosion current density (Jcorr) and corrosion potential (Ecorr) were determined via the potentiodynamic polarisation test. The results showed better corrosion characteristics of amorphous alloys. The addition of 2 at.% copper to the Al74Ni16Si10 alloy improved pitting corrosion resistance without significant effect on the corrosion current and potential. In immersion tests at 25 °C, the presence of copper resulted in an increase in the corrosion rate of about 300% for both amorphous and crystalline alloys. At a temperature of 50 °C, this increase is on average 130%. The apparent difference between the results of the two test methods is discussed in terms of the imperfections on the surface of rapidly solidified ribbons. The results of this study will contribute to a more complex understanding of the nature of amorphous alloys and their application.
Effect of Sr on Microstructure and Strengthening Mechanism of Al-4.6Mg Alloy
Authors: Yang Zhanshou , Dong Yaping , Li Wu , Liu Xin , Feng Haitao
Published: August 2023

The as-cast Al-4.6Mg alloy was subjected to deformation and sensitization–desensitization heat treatment, and then the microstructure and the enhancement mechanism of Sr were investigated by optical microscopy, scanning electron microscopy–energy-dispersive spectroscopy, electron backscatter diffraction, and transmission electron microscopy. The precipitation phases of Al-4.6Mg alloy were mainly β-Al3Mg2, Al6Mn, and Al6(Mn Cr), and the nanoscale precipitation phases were Al3Mn and Al11Mn4. The formation of β-Al3Mg2 was hindered by the addition of 0.1 wt.% Sr. In addition, the precipitate phase Al4Sr and the nano-sized precipitate phase τ-Al38Mg58Sr4 were uniformly distributed in the spherical matrix. The addition of Sr promoted the redissolution of Mg atoms in Al-4.6Mg alloy, increasing the solubility of Mg in the α-Al matrix from 4.7 wt.% to 5.1 wt.%. The microstructure analysis showed that Sr addition inhibited the recovery and recrystallization of the alloy because the Sr element elevated the recrystallization temperature. As a result, the grain deformation was intensified, the grain size was decreased from 6.96 μm to 5.39 μm, the low-angle grain boundaries were increased from 78.7 at % to 84.6 at %, and the high-angle grain boundaries were increased from 21.3 at % to 15.4 at %. Furthermore, the mechanical properties of the alloy were significantly improved, and the plasticity degraded after the addition of the Sr element. The yield strength of the alloy was enhanced mainly through fine grain strengthening, dispersion strengthening, solid solution strengthening, and working hardening. The strengthening mechanisms were analyzed in detail.
Optimization of Johnson–Cook Constitutive Model Parameters Using the Nesterov Gradient-Descent Method
Authors: Zelepugin Sergey A. , Cherepanov Roman O. , Pakhnutova Nadezhda V.
Published: August 2023

Numerical simulation of impact and shock-wave interactions of deformable solids is an urgent problem. The key to the adequacy and accuracy of simulation is the material model that links the yield strength with accumulated plastic strain, strain rate, and temperature. A material model often used in engineering applications is the empirical Johnson–Cook (JC) model. However, an increase in the impact velocity complicates the choice of the model constants to reach agreement between numerical and experimental data. This paper presents a method for the selection of the JC model constants using an optimization algorithm based on the Nesterov gradient-descent method. A solution quality function is proposed to estimate the deviation of calculations from experimental data and to determine the optimum JC model parameters. Numerical calculations of the Taylor rod-on-anvil impact test were performed for cylindrical copper specimens. The numerical simulation performed with the optimized JC model parameters was in good agreement with the experimental data received by the authors of this paper and with the literature data. The accuracy of simulation depends on the experimental data used. For all considered experiments, the calculation accuracy (solution quality) increased by 10%. This method, developed for selecting optimized material model constants, may be useful for other models, regardless of the numerical code used for high-velocity impact simulations.
Production of Bio-Based Polyol from Coconut Fatty Acid Distillate (CFAD) and Crude Glycerol for Rigid Polyurethane Foam Applications
Authors: Salcedo Ma. Louella D. , Omisol Christine Joy M. , Maputi Anthony O. , Estrada Dave Joseph E. , Aguinid Blessy Joy M. , Asequia Dan Michael A. , Erjeno Daisy Jane D. , Apostol Glenn , Siy Henry , Malaluan Roberto M. , Alguno Arnold C. , Dumancas Gerard G. , Lubguban Arnold A.
Published: August 2023

This study propounds a sustainable alternative to petroleum-based polyurethane (PU) foams, aiming to curtail this nonrenewable resource’s continued and uncontrolled use. Coconut fatty acid distillate (CFAD) and crude glycerol (CG), both wastes generated from vegetable oil processes, were utilized for bio-based polyol production for rigid PU foam application. The raw materials were subjected to catalyzed glycerolysis with alkaline-alcohol neutralization and bleaching. The resulting polyol possessed properties suitable for rigid foam application, with an average OH number of 215 mg KOH/g, an acid number of 7.2983 mg KOH/g, and a Gardner color value of 18. The polyol was used to prepare rigid PU foam, and its properties were determined using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis/derivative thermogravimetric (TGA/DTA), and universal testing machine (UTM). Additionally, the cell foam morphology was investigated by scanning electron microscope (SEM), in which most of its structure revealed an open-celled network and quantified at 92.71% open-cell content using pycnometric testing. The PU foam thermal and mechanical analyses results showed an average compressive strength of 210.43 kPa, a thermal conductivity of 32.10 mW·m−1K−1, and a density of 44.65 kg·m−3. These properties showed its applicability as a type I structural sandwich panel core material, thus demonstrating the potential use of CFAD and CG in commercial polyol and PU foam production.
An Improved Incremental Procedure for the Ground Reaction Based on Hoek-Brown Failure Criterion in the Tunnel Convergence-Confinement Method
Authors: Lee Yu-Lin , Ma Chi-Huang , Lee Chi-Min
Published: August 2023

The purpose of this study is to introduce the Hoek–Brown nonlinear failure criterion into the convergence–confinement method (CCM), which is based on the linear failure criterion, and implant it into the ground reaction curve (GRC) in this theory. Based on consistent and rigorous theoretical analysis and according to the mechanical relationships, the principle of equilibrium, the material constitutive law, and the strain/displacement compatibility equation are used to deduce the closed-form analytical solution of the stress/displacement of the rock mass in the plastic region and to complete the simulation and interpretation of the nonlinear behavior of surrounding rock due to the advancing excavation of a circular tunnel. In this paper, confinement loss is regarded as the concept of increment in numerical analysis, and the calculation process and analysis steps of the explicit analysis method (EAM) are proposed. This method can not only realize the calculation of analytical solutions but can also be performed using simple spreadsheets. In addition, to verify the feasibility of this calculation method, this study uses published data to verify the validity of the analytical solution implemented by the incremental procedure and to study the influence of nonlinear failure criteria on the GRC, especially the mechanical behavior at the intrados of the tunnel and the distributions of tress/displacement on the cross-section of the tunnel. A comparison between the published results and the proposed solution in this study reveals consistent and favorable trends.
BAE: Anomaly Detection Algorithm Based on Clustering and Autoencoder
Authors: Wang Dongqi , Nie Mingshuo , Chen Dongming
Published: August 2023

In this paper, we propose an outlier-detection algorithm for detecting network traffic anomalies based on a clustering algorithm and an autoencoder model. The BIRCH clustering algorithm is employed as the pre-algorithm of the autoencoder to pre-classify datasets with complex data distribution characteristics, while the autoencoder model is used to detect outliers based on a threshold. The proposed BIRCH-Autoencoder (BAE) algorithm has been tested on four network security datasets, KDDCUP99, UNSW-NB15, CICIDS2017, and NSL-KDD, and compared with representative algorithms. The BAE algorithm achieved average F-scores of 96.160, 81.132, and 91.424 on the KDDCUP99, UNSW-NB15, and CICIDS2017 datasets, respectively. These experimental results demonstrate that the proposed approach can effectively and accurately detect anomalous data.
Tissue Engineering and Stem Cell Therapy in Neurogenic Bladder Dysfunction: Current and Future Perspectives
Authors: Topoliova Katarina , Harsanyi Stefan , Danisovic Lubos , Ziaran Stanislav
Published: August 2023

Tissue engineering (TE) is a rapidly evolving biomedical discipline that can play an important role in treating neurogenic bladder dysfunction and compensating for current conventional options’ shortcomings. This review aims to analyze the current status of preclinical and clinical trials and discuss what could be expected in the future based on the current state of the art. Although most preclinical studies provide promising results on the effectiveness of TE and stem cell therapies, the main limitations are mainly the very slow translation of preclinical trials to clinical trials, lack of quality research on neurogenic preconditions of neurogenic bladder dysfunction outside of the spinal cord injury and varying therapeutic methods of the existing research that lacks a standardized approach.
Identification of Secondary Metabolites from the Mangrove-Endophyte Lasiodiplodia iranensis F0619 by UPLC-ESI-MS/MS
Authors: Delgado Gómez Lizbeth M. , Torres-Mendoza Daniel , Hernández-Torres Kathleen , Ortega Humberto E. , Cubilla-Rios Luis
Published: August 2023

Lasiodiplodia is a widely distributed fungal genus, frequently found in tropical and subtropical regions where it can cause disease in important crops. It represents a promising source of active secondary metabolites with uses in chemical, pharmaceutical, and agrochemical processes. In this study, the strain Lasiodiplodia iranensis F0619 was isolated from the mangrove Avicennia ger-minans, collected from Sarigua National Park in the Republic of Panama. Fractions of crude extract were analyzed by UPLC-ESI-MS/MS, and five compounds, previously reported from Lasiodiplodia genus were identified, including 11,12-didehydro-7-iso-jasmonic acid (1), 4,5-didehydro-7-iso-jasmonic acid (2), cyclo-(L-Leu-L-Pro) (3), jasmonate-threonine (4), and abscisic acid (5). We describe and analyze their MS/MS fragmentation patterns to confirm the compounds ‘chemical structures.
Single-Line Multi-Channel Flexible Stress Sensor Arrays
Authors: Yang Jiayi , Chen Yuanyuan , Liu Shuoyan , Liu Chang , Ma Tian , Luo Zhenmin , Ge Gang
Published: August 2023

Flexible stress sensor arrays, comprising multiple flexible stress sensor units, enable accurate quantification and analysis of spatial stress distribution. Nevertheless, the current implementation of flexible stress sensor arrays faces the challenge of excessive signal wires, resulting in reduced deformability, stability, reliability, and increased costs. The primary obstacle lies in the electric amplitude modulation nature of the sensor unit’s signal (e.g., resistance and capacitance), allowing only one signal per wire. To overcome this challenge, the single-line multi-channel signal (SLMC) measurement has been developed, enabling simultaneous detection of multiple sensor signals through one or two signal wires, which effectively reduces the number of signal wires, thereby enhancing stability, deformability, and reliability. This review offers a general knowledge of SLMC measurement beginning with flexible stress sensors and their piezoresistive, capacitive, piezoelectric, and triboelectric sensing mechanisms. A further discussion is given on different arraying methods and their corresponding advantages and disadvantages. Finally, this review categorizes existing SLMC measurement methods into RLC series resonant sensing, transmission line sensing, ionic conductor sensing, triboelectric sensing, piezoresistive sensing, and distributed fiber optic sensing based on their mechanisms, describes the mechanisms and characteristics of each method and summarizes the research status of SLMC measurement.