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18 pages, 1880 KB  
Article
Proposal for a Battery to Evaluate Functional Capacity in Older Adults with Disabilities
by Josu Ascondo, Iñaki Llodio, Bingen Marcos-Rivero, Cristina Granados, Sheila Romero, Aitor Iturricastillo and Javier Yanci
Sensors 2025, 25(6), 1813; https://doi.org/10.3390/s25061813 - 14 Mar 2025
Viewed by 776
Abstract
The purpose was to design and validate a battery of physical tests, called EFEPD-1.0, adapted to assess functionality in people with disabilities. In addition, we sought to analyze the validity and reliability of this battery both for the total group and differentiated by [...] Read more.
The purpose was to design and validate a battery of physical tests, called EFEPD-1.0, adapted to assess functionality in people with disabilities. In addition, we sought to analyze the validity and reliability of this battery both for the total group and differentiated by sex. A total of 43 adults with disabilities (32 women and 11 men) participated (57.11 ± 10.12 years). The battery was composed of five blocks of functionality: neuromuscular, combined actions, acceleration, balance, and cardiovascular. The neuromuscular functionality was measured by the vertical and horizontal jump test using the optical system (Opto Jump Next®, Microgate, Bolzano, Italy) as well as the Hand Grip (HG) test using a (5030J1, Jamar®, Sammons Preston, Inc, Nottinghamshire, UK) hand dynamometer. The combined actions and balance functionality were assessed with the Time Up and Go (TUG) test, the 30 s Chair Stand (30CTS) test, and the One-Leg Stance (OLS) test measured by a manual stopwatch (HS-80TW-1EF, Casio®, Tokyo, Japan). The acceleration functionality was evaluated through 20 m sprints and the 505 change of direction (COD505) test, using the (Microgate, Witty®, Bolzano, Italy) photocell system. The cardiovascular functionality was evaluated with the Six-Minute Walking Test (6MWT), where heart rate was monitored using the (Polar Team Sport System®, Polar Electro Oy, Kempele, Finland), and additional walking mechanics were recorded with Stryd (Stryd Everest 12 Firmware 1.18 Software 3, Stryd Inc., Boulder, CO, USA). The results showed that the intraclass correlation coefficients (ICCs) ranged from moderate to almost perfect (ICC = 0.65–0.98) between test repetitions. Some tests could significantly differentiate (p < 0.05) men and women, highlighting better neuromuscular capacity in men and better balance in women. The correlations between tests showed significant convergent validity. The Evaluation of Functionality in the Disabled Population (EFEPD-1.0) battery not only consistently measures functional capacities in people with disabilities, but it can also discriminate between different subgroups within this population. Full article
(This article belongs to the Collection Sensors for Globalized Healthy Living and Wellbeing)
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17 pages, 2220 KB  
Article
Gait Parameters Can Be Derived Reliably and Validly from Augmented Reality Glasses in People with Parkinson’s Disease Performing 10-m Walk Tests at Comfortable and Fast Speeds
by Pieter F. van Doorn, Daphne J. Geerse, Jara S. van Bergem, Eva M. Hoogendoorn, Edward Nyman and Melvyn Roerdink
Sensors 2025, 25(4), 1230; https://doi.org/10.3390/s25041230 - 18 Feb 2025
Cited by 2 | Viewed by 1296
Abstract
The 10-m walk test (10MWT) is a stopwatch-based clinical mobility assessment. To better understand mobility limitations, 10MWT test completion times may be complemented with gait parameters like step length. State-of-the-art augmented reality (AR) glasses can potentially do this given their unique 3D-positional data [...] Read more.
The 10-m walk test (10MWT) is a stopwatch-based clinical mobility assessment. To better understand mobility limitations, 10MWT test completion times may be complemented with gait parameters like step length. State-of-the-art augmented reality (AR) glasses can potentially do this given their unique 3D-positional data from which gait parameters may be derived. We examined the test-retest reliability, concurrent validity, and face validity of gait parameters derived from AR glasses during a 10MWT in 20 people with Parkinson’s disease, performed at self-selected comfortable and fast-but-safe walking speeds. AR-derived 10MWT completion times and gait parameters (mean step length, cadence, and maximal gait speed) were compared across repetitions and with lab-based (Interactive Walkway) and clinical (stopwatch) reference systems. Good-to-excellent test-retest reliability statistics were observed for test completion times and gait parameters for all systems and conditions alike. Concurrent validity was demonstrated between AR, lab-based, and clinical references for test completion times (good-to-excellent agreement: ICC > 0.879) and gait parameters (excellent agreement: ICC > 0.942). Face validity was confirmed by significant differences in test completion times and gait parameters between speed conditions in a-priori expected directions. These findings support the conclusion that gait parameters can be derived reliably and validly from AR glasses in people with Parkinson’s disease. Full article
(This article belongs to the Special Issue Digital Health Technologies for Rehabilitation and Physical Therapy)
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14 pages, 267 KB  
Article
Evaluation of Pain During Hysteroscopy Under Local Anesthesia, Including the Stages of the Procedure
by Adrian Nowak, Karolina Chmaj-Wierzchowska, Agnieszka Lach, Adam Malinger and Maciej Wilczak
J. Clin. Med. 2024, 13(23), 7030; https://doi.org/10.3390/jcm13237030 - 21 Nov 2024
Cited by 1 | Viewed by 1406
Abstract
Hysteroscopy is an endoscopic diagnostic and therapeutic method traditionally performed under general anesthesia but increasingly under local anesthesia. Today, it is considered the gold standard in gynecology. This minimally invasive procedure allows for a detailed assessment of the uterine cavity’s interior and the [...] Read more.
Hysteroscopy is an endoscopic diagnostic and therapeutic method traditionally performed under general anesthesia but increasingly under local anesthesia. Today, it is considered the gold standard in gynecology. This minimally invasive procedure allows for a detailed assessment of the uterine cavity’s interior and the removal of abnormal changes within it and is applicable to patients of all ages. Background/Objectives: The purpose of the present study was to evaluate pain during hysteroscopy under local anesthesia at different stages of the procedure, identifying which stage is the most painful (GUBBINI Mini Hystero-Resectoscope; Tontarra Medizintechnik, Tuttlingen, Germany). Methods: The study included patients between the ages of 21 and 80 years. They were divided into two groups: the diagnostic hysteroscopy (HD) and the operative hysteroscopy (HO) groups. Pain measurements on the VAS scale were taken at each stage of the hysteroscopic procedure. After each stage, the operator asked the patient to indicate the maximum perceived pain value: after pericervical anesthesia was administered (VAS1), during the installation of equipment (between the removal of the speculum and the insertion of the hysteroscope into the vagina) (VAS2), after insertion of the hysteroscope and visualization of the external orifice of the cervical canal (VAS3), after passage of the hysteroscope through the cervical canal (VAS4), and after completion of the procedure in the uterine cavity (VAS5). The duration of each stage of the procedure was measured with a stopwatch: administration of pericervical anesthesia (T1), time between the removal of the speculum and the insertion of the hysteroscope into the vagina (T2), insertion of the hysteroscope into the vagina until the outer orifice of the cervical canal became visible (T3), passage of the hysteroscope through the cervical canal (T4), and the hysteroscopy procedure itself (T5). Results: The highest pain rating was for the canal passage stage (VAS4: 2.47 ± 2.48 points), followed by the procedure itself (VAS5: 2.12 ± 2.33 points). Anesthesia was also reported as quite painful, while the lowest pain was noted during the assembly stage. Overall pain scores for the entire procedure (VASmax) ranged from 3.5 ± 2.37. Conclusion: In conclusion, we found that the passage through the cervical canal was the most painful moment. Overall, hysteroscopy under pericervical anesthesia was not associated with significant pain. Special attention should be given to postmenopausal patients, as they experience more pain during the passage of the hysteroscope through the cervical canal. This group may benefit from additional pain management strategies during the procedure. Full article
(This article belongs to the Section Anesthesiology)
13 pages, 12309 KB  
Article
The Preparation of a Low-Cost, Structurally Simple Triboelectric Nanogenerator Based on Fullerene Carbon Soot-Doped Polydimethylsiloxane Composite Film
by Shujie Yang, Wen Zhao, Oleg Tolochko and Tatiana Larionova
Materials 2024, 17(11), 2470; https://doi.org/10.3390/ma17112470 - 21 May 2024
Cited by 2 | Viewed by 1672
Abstract
Triboelectric nanogenerators (TENGs) have emerged as viable micro power sources for an array of applications. Since their inception in 2012, TENGs have been the subject of significant advancements in terms of structural design and the development of friction materials. Despite these advancements, the [...] Read more.
Triboelectric nanogenerators (TENGs) have emerged as viable micro power sources for an array of applications. Since their inception in 2012, TENGs have been the subject of significant advancements in terms of structural design and the development of friction materials. Despite these advancements, the complexity of their structural designs and the use of costly friction materials hinder their practical application. This study introduces a simplified TENG model utilizing an economical composite film of fullerene carbon soot (FS)-doped polydimethylsiloxane (PDMS) (FS-TENG). It confirms the FS-TENG’s ability to convert mechanical energy into electrical energy, as demonstrated through experimental validation. The generated electricity by the FS-TENG can power devices such as light-emitting diodes (LEDs), digital watches, kitchen timers, and sports stopwatches, highlighting its efficiency. This research enhances the development of TENGs featuring low-cost, streamlined structures for sustainable and autonomous energy sensing applications. Full article
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15 pages, 2675 KB  
Article
Intra and Inter-Device Reliabilities of the Instrumented Timed-Up and Go Test Using Smartphones in Young Adult Population
by Thâmela Thaís Santos dos Santos, Amélia Pasqual Marques, Luis Carlos Pereira Monteiro, Enzo Gabriel da Rocha Santos, Gustavo Henrique Lima Pinto, Anderson Belgamo, Anselmo de Athayde Costa e Silva, André dos Santos Cabral, Szymon Kuliś, Jan Gajewski, Givago Silva Souza, Tacyla Jesus da Silva, Wesley Thyago Alves da Costa, Railson Cruz Salomão and Bianca Callegari
Sensors 2024, 24(9), 2918; https://doi.org/10.3390/s24092918 - 3 May 2024
Cited by 1 | Viewed by 3039
Abstract
The Timed-Up and Go (TUG) test is widely utilized by healthcare professionals for assessing fall risk and mobility due to its practicality. Currently, test results are based solely on execution time, but integrating technological devices into the test can provide additional information to [...] Read more.
The Timed-Up and Go (TUG) test is widely utilized by healthcare professionals for assessing fall risk and mobility due to its practicality. Currently, test results are based solely on execution time, but integrating technological devices into the test can provide additional information to enhance result accuracy. This study aimed to assess the reliability of smartphone-based instrumented TUG (iTUG) parameters. We conducted evaluations of intra- and inter-device reliabilities, hypothesizing that iTUG parameters would be replicable across all experiments. A total of 30 individuals participated in Experiment A to assess intra-device reliability, while Experiment B involved 15 individuals to evaluate inter-device reliability. The smartphone was securely attached to participants’ bodies at the lumbar spine level between the L3 and L5 vertebrae. In Experiment A, subjects performed the TUG test three times using the same device, with a 5 min interval between each trial. Experiment B required participants to perform three trials using different devices, with the same time interval between trials. Comparing stopwatch and smartphone measurements in Experiment A, no significant differences in test duration were found between the two devices. A perfect correlation and Bland–Altman analysis indicated good agreement between devices. Intra-device reliability analysis in Experiment A revealed significant reliability in nine out of eleven variables, with four variables showing excellent reliability and five showing moderate to high reliability. In Experiment B, inter-device reliability was observed among different smartphone devices, with nine out of eleven variables demonstrating significant reliability. Notable differences were found in angular velocity peak at the first and second turns between specific devices, emphasizing the importance of considering device variations in inertial measurements. Hence, smartphone inertial sensors present a valid, applicable, and feasible alternative for TUG assessment. Full article
(This article belongs to the Special Issue Human Movement Monitoring Using Wearable Sensor Technology)
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19 pages, 4082 KB  
Article
Impact of the Product Master Data Quality on the Logistics Process Performance
by Diana Božić, Margareta Živičnjak, Ratko Stanković and Andrej Ignjatić
Logistics 2024, 8(2), 43; https://doi.org/10.3390/logistics8020043 - 12 Apr 2024
Cited by 1 | Viewed by 3737
Abstract
Background: The importance of up-to-date product master data in the digital age should not be underestimated. However, companies still struggle to ensure high-quality product data, especially in the field of logistics. Hence, the focus of our research lies in the disregard of the [...] Read more.
Background: The importance of up-to-date product master data in the digital age should not be underestimated. However, companies still struggle to ensure high-quality product data, especially in the field of logistics. Hence, the focus of our research lies in the disregard of the importance of product data quality to the performance of logistics processes. Methods: The analysis of the influence of product data on the performance of logistics processes was carried out using data from two fast-moving consumer goods (FMCG) distribution and retail companies. Data were gathered via interviews, while process activities were timed using a stopwatch, and interruptions were documented. The significance of the impact was determined using inferential statistical procedures based on the variable and the measurement scale type employed. Results: The quality of product master data has a significant impact on the performance of logistics processes; while managers are aware of the complications, they lack the motivation to detect and analyse such inaccuracies. Conclusions: The findings enhance comprehension of the obstacles generated by inadequate product data in logistics, which obstruct optimisation, and offer numerical proof of the impact of product data quality on logistics performance, thus expanding the current body of research. Full article
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11 pages, 498 KB  
Brief Report
Validity and Reliability of a Smartphone Application for Home Measurement of Four-Meter Gait Speed in Older Adults
by Pei-An Lee, Clark DuMontier, Wanting Yu, Levi Ask, Junhong Zhou, Marcia A. Testa, Dae Kim, Gregory Abel, Tom Travison, Brad Manor and On-Yee Lo
Bioengineering 2024, 11(3), 257; https://doi.org/10.3390/bioengineering11030257 - 6 Mar 2024
Cited by 5 | Viewed by 3121
Abstract
The four-meter gait speed (4MGS) is a recommended physical performance test in older adults but is challenging to implement clinically. We developed a smartphone application (App) with a four-meter ribbon for remote 4MGS testing at home. This study aimed to assess the validity [...] Read more.
The four-meter gait speed (4MGS) is a recommended physical performance test in older adults but is challenging to implement clinically. We developed a smartphone application (App) with a four-meter ribbon for remote 4MGS testing at home. This study aimed to assess the validity and reliability of this smartphone App-based assessment of the home 4MGS. We assessed the validity of the smartphone App by comparing it against a gold standard video assessment of the 4MGS conducted by study staff visiting community-dwelling older adults and against the stopwatch-based measurement. Moreover, we assessed the test–retest reliability in two supervised sessions and three additional sessions performed by the participants independently, without staff supervision. The 4MGS measured by the smartphone App was highly correlated with video-based 4MGS (r = 0.94), with minimal differences (mean = 0.07 m/s, ± 1.96 SD = 0.12) across a range of gait speeds. The test–retest reliability for the smartphone App 4MGS was high (ICC values: 0.75 to 0.93). The home 4MGS in older adults can be measured accurately and reliably using a smartphone in the pants pocket and a four-meter strip of ribbon. Leveraging existing technology carried by a significant portion of the older adult population could overcome barriers in busy clinical settings for this well-established objective mobility test. Full article
(This article belongs to the Special Issue Body-Worn Sensors for Biomedical Applications)
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15 pages, 3845 KB  
Article
Calming Hungarian Grey Cattle in Headlocks Using Processed Nasal Vocalization of a Mother Cow
by Ádám Lenner, Zoltán Lajos Papp, Csaba Szabó and István Komlósi
Animals 2024, 14(1), 135; https://doi.org/10.3390/ani14010135 - 30 Dec 2023
Cited by 3 | Viewed by 2524
Abstract
Sound analysis is an important field of research for improving precision livestock farming systems. If the information carried by livestock sounds is interpreted correctly, it could be used to improve management and welfare assessment in this field. Therefore, we hypothesized that the nasal [...] Read more.
Sound analysis is an important field of research for improving precision livestock farming systems. If the information carried by livestock sounds is interpreted correctly, it could be used to improve management and welfare assessment in this field. Therefore, we hypothesized that the nasal vocalization of a mother cow could have a calming effect on conspecifics. The nasal vocalization in our study was recorded from a mother cow (not part of the test herd) while it was licking its day-old calf. The raw sound was analyzed, cleaned from noises, and the most representative vocalization was lengthened to two minutes. Thirty cows having calves were randomly selected from eighty Hungarian grey cattle cows. Two test days were selected, one week apart; the weather circumstances in both days were similar. The herd was collected in a paddock, and the test site (a restraining crate with a headlock) was 21 m away from them. The cows from the herd were gently moved to the restraining crate, and, after the installation of the headlock, Polar® heart rate monitors were fixed on the animals. The recording of the RR intervals was carried out for two minutes. On day one of the test, the processed nasal sound was played to every second cow during the heart rate monitoring. When the sound ended, the heart rate monitor was removed. On test day two, the sound and no sound treatments were switched among the participating cows. At the end of the measurement, the headlock was opened, letting the animals out voluntarily, and a flight test was performed along a 5 m distance. The time needed to pass the 5 m length was measured with a stopwatch and divided by the distance. The RR intervals were analyzed with the Kubios HRV Standard (ver. 3.5.0) software. The following data were recorded for the entire measurement: average and maximum heart rate; SD1 and SD2; pNN50; VLF, LF, and HF. The quasi-periodic signal detected in the sound analyses can hardly be heard, even when it is enhanced to the maximum. This can be considered a vibration probably caused by the basis of articulation, such as a vibration of the tongue, for example. The SD2/SD1 ratio (0.97 vs. 1.07 for the animals having no sound and sound played, respectively, p = 0.0110) and the flight speed (0.92 vs. 1.08 s/m for the animals having no sound and sound played, respectively, p = 0.0409) indicate that the sound treatment had a calming effect on the restrained cows. The day of the test did not influence any of the measured parameters; therefore, no effect of the routine was observed. The yes–no sequence of the sound treatment significantly reduced the pNN50 and flight speed values, suggesting a somewhat more positive association with the headlock and the effectiveness of the processed nasal sound. In conclusion, we have demonstrated that, by means of sound analyses, not only information about individuals and the herd can be gathered but that, with proper processing, the sound obtained can be used to improve animal welfare. Full article
(This article belongs to the Section Cattle)
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12 pages, 3938 KB  
Article
Effects of Er,Cr: YSGG Laser Application in De-Bonding of Different Ceramic Veneer Materials (In Vitro Study)
by Bassam Karem Amin
Coatings 2023, 13(8), 1352; https://doi.org/10.3390/coatings13081352 - 2 Aug 2023
Cited by 2 | Viewed by 2704
Abstract
Background: Ceramic restorations are widely used nowadays as the esthetic demand has increased in the worldwide population, and lithium disilicate and feldspathic porcelain materials are the most widely used veneer materials. The traditional removal procedure for veneers was recently replaced with the use [...] Read more.
Background: Ceramic restorations are widely used nowadays as the esthetic demand has increased in the worldwide population, and lithium disilicate and feldspathic porcelain materials are the most widely used veneer materials. The traditional removal procedure for veneers was recently replaced with the use of laser technology to debond the veneers so that the de-bonded veneers can be preserved and re-used. Aim: Up to now, there have been few studies regarding using lasers to remove ceramic laminate; thus, it is clear why this research topic is important for examining the efficiency of lasers in the use of de-bonding for different ceramic laminates with varying compositions and materials. Materials and Methods: This study employed forty-five normal human maxillary first premolars with comparable proportions. The forty-five teeth were initially split into three groups of fifteen teeth, and the teeth were chosen at random. Each group fused pairs of various ceramic materials. A total of fifteen teeth in the first group underwent feldspathic porcelain restorations. The second group contained fifteen restorations made of lithium disilicate glass-ceramic CAD-CAM. In the third group, fifteen teeth were restored using glass-ceramic that had a lithium disilicate glass-ceramic ingot. The RelyX Veneer A1 shade, available from 3M EPSE in the United States, was used to bond all the samples. The specimens were then submerged for approximately 24 h in distilled water at 37 degrees Celsius in order to simulate the conditions in an oral cavity. An Er,Cr: YSGG laser (Waterlase, iPlus, Biolase, from USA) was used with a turbo headpiece and an MX7 sapphire tip for irradiation. Results: The time needed for the ceramic disc to debond was calculated using a digital stopwatch. The average removal times for the feldspathic porcelain, lithium disilicate glass-ceramic ingot, and lithium disilicate glass-ceramic CAD-CAM were 10.067 ± 1.668 s, 5.200 ± 1.146 s, and 5.133 ± 1.125 s, while the removal times ranged from 8–12 s, 4–7 s, and 4–7 s, respectively. Compared to the other ceramic materials, de-bonding the feldspathic porcelain took longer. Conclusions: According to this study, the Er,Cr: YSGG laser application using the same study parameters made it simpler to de-bond lithium disilicate and feldspathic porcelain. Lithium disilicate, as opposed to feldspathic porcelain, transmits laser light more effectively; hence, the results varied depending on the materials, and the debonding occurred primarily at the veneer–cement interface. Full article
(This article belongs to the Special Issue Laser-Assisted Processes and Thermal Treatments of Materials)
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24 pages, 14012 KB  
Article
Operational Performance and Energy Efficiency of MEX 3D Printing with Polyamide 6 (PA6): Multi-Objective Optimization of Seven Control Settings Supported by L27 Robust Design
by Constantine David, Dimitrios Sagris, Markos Petousis, Nektarios K. Nasikas, Amalia Moutsopoulou, Evangelos Sfakiotakis, Nikolaos Mountakis, Chrysa Charou and Nectarios Vidakis
Appl. Sci. 2023, 13(15), 8819; https://doi.org/10.3390/app13158819 - 30 Jul 2023
Cited by 30 | Viewed by 3730
Abstract
Both energy efficiency and robustness are popular demands for 3D-printed components nowadays. These opposing factors require compromises. This study examines the effects of seven general control variables on the energy demands and the compressive responses of polyamide (PA6) material extrusion (MEX) 3D printed [...] Read more.
Both energy efficiency and robustness are popular demands for 3D-printed components nowadays. These opposing factors require compromises. This study examines the effects of seven general control variables on the energy demands and the compressive responses of polyamide (PA6) material extrusion (MEX) 3D printed samples. Nozzle Temperature, Layer Thickness, Orientation Angle, Raster Deposition Angle, Printing Speed, Bed Temperature, and Infill Density were studied. An L27 orthogonal array was compiled with five replicas. A total of 135 trials were conducted, following the ASTM D695-02a specifications. The stopwatch method was used to assess the construction time and energy usage. The compressive strength, toughness, and elasticity modulus were experimentally determined. The Taguchi technique ranks each control parameter’s impact on each response measure. The control parameter that had the greatest impact on both energy use and printing time was layer thickness. Additionally, the infill density had the greatest influence on the compressive strength. Quadratic regression model equations were formed for each of the response measures. The ideal compromise between mechanical strength and energy efficiency is now reported, with merit related to technological and economic benefits. Full article
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18 pages, 5997 KB  
Article
Impact of Pavement Defects on Traffic Operational Performance
by Ibrahim H. Hashim, Rania M. Badawy and Usama Heneash
Sustainability 2023, 15(10), 8293; https://doi.org/10.3390/su15108293 - 19 May 2023
Cited by 7 | Viewed by 3454
Abstract
The present research investigates the influence of pavement distresses on traffic operational performance in terms of speed and capacity. The pavement distresses are expressed by the pavement condition index (PCI). Three roads of multi-lane highways located on the road network of Kafrelsheikh governorate, [...] Read more.
The present research investigates the influence of pavement distresses on traffic operational performance in terms of speed and capacity. The pavement distresses are expressed by the pavement condition index (PCI). Three roads of multi-lane highways located on the road network of Kafrelsheikh governorate, Egypt, were chosen as a case study. Road geometry, pavement condition characteristics, and traffic volume were collected manually from 23 sections for field data surveys. For speed measurements, spot speed data were gathered using the stopwatch method under the free-flow conditions, and the percentile speeds (V50% and V85%) have been calculated for different vehicles classes. Traffic capacity was determined via extrapolation of the quadratic function. Regression analysis models were created to express the relationships of both the percentile speeds and traffic capacity as dependent variables, and three independent variables (PCI, lane, and shoulder widths). These empirical mathematical relations help in developing road design and maintenance works on multi-lane highways. The main conclusion of the study demonstrated that traffic operational performance was more significantly affected by pavement distresses than road geometry. Moreover, the results indicated that pavement distresses have a significant impact on light vehicles more than heavy ones. Full article
(This article belongs to the Section Sustainable Transportation)
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25 pages, 6874 KB  
Article
Energy Consumption vs. Tensile Strength of Poly[methyl methacrylate] in Material Extrusion 3D Printing: The Impact of Six Control Settings
by Nectarios Vidakis, Markos Petousis, Nikolaos Mountakis, Amalia Moutsopoulou and Emmanuel Karapidakis
Polymers 2023, 15(4), 845; https://doi.org/10.3390/polym15040845 - 8 Feb 2023
Cited by 30 | Viewed by 2850
Abstract
The energy efficiency of material extrusion additive manufacturing has a significant impact on the economics and environmental footprint of the process. Control parameters that ensure 3D-printed functional products of premium quality and mechanical strength are an established market-driven requirement. To accomplish multiple objectives [...] Read more.
The energy efficiency of material extrusion additive manufacturing has a significant impact on the economics and environmental footprint of the process. Control parameters that ensure 3D-printed functional products of premium quality and mechanical strength are an established market-driven requirement. To accomplish multiple objectives is challenging, especially for multi-purpose industrial polymers, such as the Poly[methyl methacrylate]. The current paper explores the contribution of six generic control factors (infill density, raster deposition angle, nozzle temperature, print speed, layer thickness, and bed temperature) to the energy performance of Poly[methyl methacrylate] over its mechanical performance. A five-level L25 Taguchi orthogonal array was composed, with five replicas, involving 135 experiments. The 3D printing time and the electrical consumption were documented with the stopwatch approach. The tensile strength, modulus, and toughness were experimentally obtained. The raster deposition angle and the printing speed were the first and second most influential control parameters on tensile strength. Layer thickness and printing speed were the corresponding ones for the energy consumption. Quadratic regression model equations for each response metric over the six control parameters were compiled and validated. Thus, the best compromise between energy efficiency and mechanical strength is achievable, and a tool creates significant value for engineering applications. Full article
(This article belongs to the Special Issue Polymers for Additive Manufacturing)
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25 pages, 14776 KB  
Article
Mechanical Performance over Energy Expenditure in MEX 3D Printing of Polycarbonate: A Multiparametric Optimization with the Aid of Robust Experimental Design
by Nectarios Vidakis, Markos Petousis, Constantine N. David, Dimitrios Sagris, Nikolaos Mountakis and Emmanuel Karapidakis
J. Manuf. Mater. Process. 2023, 7(1), 38; https://doi.org/10.3390/jmmp7010038 - 1 Feb 2023
Cited by 28 | Viewed by 2690
Abstract
Sustainability and energy efficiency of additive manufacturing (AM) is an up-to-date industrial request. Likewise, the claim for 3D-printed parts with capable mechanical strength remains robust, especially for polymers that are considered high-performance ones, such as polycarbonates in material extrusion (MEX). This paper explains [...] Read more.
Sustainability and energy efficiency of additive manufacturing (AM) is an up-to-date industrial request. Likewise, the claim for 3D-printed parts with capable mechanical strength remains robust, especially for polymers that are considered high-performance ones, such as polycarbonates in material extrusion (MEX). This paper explains the impact of seven generic control parameters (raster deposition angle; orientation angle; layer thickness; infill density; nozzle temperature; bed temperature; and printing speed) on the energy consumption and compressive performance of PC in MEX AM. To meet this goal, a three-level L27 Taguchi experimental design was exploited. Each experimental run included five replicas (compressive specimens after the ASTM D695-02a standard), summating 135 experiments. The printing time and the power consumption were stopwatch-derived, whereas the compressive metrics were obtained by compressive tests. Layer thickness and infill density were ranked the first and second most significant factors in energy consumption. Additionally, the infill density and the orientation angle were proved as the most influential factors on the compressive strength. Lastly, quadratic regression model (QRM) equations for each response metric versus the seven control parameters were determined and evaluated. Hereby, the optimum compromise between energy efficiency and compressive strength is attainable, a tool holding excessive scientific and engineering worth. Full article
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12 pages, 700 KB  
Article
Test–Retest Reliability and Concurrent Validity of the 3 m Backward Walk Test under Single and Dual-Task Conditions in Women with Fibromyalgia
by Juan Luis Leon-Llamas, Santos Villafaina, Alvaro Murillo-Garcia, Francisco Javier Domínguez-Muñoz and Narcis Gusi
J. Clin. Med. 2023, 12(1), 212; https://doi.org/10.3390/jcm12010212 - 27 Dec 2022
Cited by 9 | Viewed by 2591
Abstract
Background: Previous studies have reported good test–retest reliability for the 3 m backward test (3MBWT) in different populations. However, reliability of the 3MBWT has not been studied in fibromyalgia (FM) under single and dual-task conditions; Methods: A total of 21 women with FM [...] Read more.
Background: Previous studies have reported good test–retest reliability for the 3 m backward test (3MBWT) in different populations. However, reliability of the 3MBWT has not been studied in fibromyalgia (FM) under single and dual-task conditions; Methods: A total of 21 women with FM participated in this study. Participants completed the Revised Fibromyalgia Impact Questionnaire and two physical fitness tests: the 3MBWT and the Timed Up and Go (TUG). The dual-task condition consisted of subtracting two by two while performing the test, starting from a random number less than 100; Results: Values showed that the 3MBWT can be considered reliable under single and dual-task conditions when measured with both a manual stopwatch and a Chronopic automatic stopwatch. A strong concurrent validity was shown of 3MBWT and TUG results in the test and retest and the different devices. The relationship between the performance of the 3MBWT in test and retest conditions under single and dual-task conditions measured with different devices and the impact of the disease were high; Conclusions: The 3MBWT is a reliable tool under the single and dual-task conditions in women with FM. It shows higher reliability values when time is taken using a Chronopic. This test also shows high concurrent validity with the TUG test. Its performance is related to the impact of the disease. Full article
(This article belongs to the Special Issue Chronic Pain: Clinical Updates and Perspectives)
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Article
Laser Er:YAG-Assisted Debonding May Be a Viable Alternative to the Conventional Method for Monocrystalline Ceramic Brackets
by Daliana-Emanuela Mocuta, Mariana I. Miron, Diana Lungeanu, Marius Mateas, Emilia Ogodescu and Carmen D. Todea
Int. J. Environ. Res. Public Health 2022, 19(21), 14564; https://doi.org/10.3390/ijerph192114564 - 6 Nov 2022
Cited by 7 | Viewed by 3529
Abstract
In orthodontic practice, due to the increased interest among patients in smile aesthetics, different types of brackets are now being used, with those most frequently applied being ones made of polycrystalline and monocrystalline ceramic. The aim of this study was to evaluate the [...] Read more.
In orthodontic practice, due to the increased interest among patients in smile aesthetics, different types of brackets are now being used, with those most frequently applied being ones made of polycrystalline and monocrystalline ceramic. The aim of this study was to evaluate the laser Er:YAG-assisted debonding technique compared to conventional methods for removing monocrystalline ceramic brackets from human teeth. The study sample included 60 vital teeth (frontals of the upper jaw) from 10 patients who had monocrystalline ceramic brackets and were in the final phase of orthodontic treatment. The debonding procedure was carried out following a split-mouth study design, using either the conventional technique or laser Er:YAG 2940 nm radiation. For each tooth, three variables were evaluated: the patient’s sujective tooth sensitivity associated with the debonding, the time required for debonding, and pulp blood flow microdynamics after the debonding. Three evaluation instruments were used to assess and quantify the treatment effects: (i) the Wong–Baker FACES Pain Rating Scale for pain assessment; (ii) a digital stopwatch/timer to measure the time required to remove the bracket; and (iii) laser Doppler flowmetry (LDF) for recording the pulp blood flow evolution. The statistical analysis of the recorded data showed a statistically significant difference between the two debonding methods regarding the tooth sensitivity during the debonding and the time required for the procedure. The subjective tooth sensitivity was reduced from a mean ± standard deviation of 3.07 ± 1.46 to 0.47 ± 0.86 on the Wong–Baker FACES scale (Wilcoxon signed rank, p < 0.001). The necessary time for debonding was reduced by 0.697 ± 0.703 s per tooth (paired t-test, p < 0.001). There was no difference in the blood microdynamics between the two debonding techniques. According to the results of this study, the laser Er:YAG-assisted debonding technique may be a viable alternative to the conventional method for monocrystalline ceramic brackets. Full article
(This article belongs to the Special Issue Dental Public Health: Issues, Challenges and Opportunities)
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