Search

In the simulation of the hole-flanging process, many had reported that the effect of mesh sensitivity on strain localizations is insignificant. In this study, mesh layouts including the number of elements along the hole circumference (CD), element sizes in radial directions (R 1) and the time discretization (or increment) sizes (T) are varied in the 3D FE simulation of 10-mm hole flanging process of DP980 thin sheets using a conical punch. Its effect on wall thickness distributions and forming load profiles are investigated. Also, the effect of punch surface meshing techniques i.e., analytical and discrete rigid on the distributions is investigated. The simulation results showed that the largest % wall thinning range around the expanded hole edges for punch displacement, S = 15 mm and 20 mm are 25.8–29.2% and 33.3–64.2%, respectively. The load-displacement curves during the continuous hole expansion are not linear for R 1 ≥ 0.5 mm. For CD70 & R 1 = 0.1 mm, the increase in T values from 0.1 s to 1.0 s has significantly increased the total simulation time by 25% due to the convergence problems. The automatic time increment mode in each step at T = 1.0 s has failed to reduce the total simulation time. The discrete rigid punch surface produces more concentrated wall thickness distributions than the analytical one, leading to higher amount of wall thinning, particularly for high S values. Since the model stiffness reduces with decreasing mesh size. It is recommended to match the simulated peak load with the experimental peak under the instability condition with a smooth hole e.g., a laser cut hole to determine the appropriate meshing method for the mesh sensitivity study. With that, the stiffness of the simulation model is calibrated with the experiment. [Display omitted] [ABSTRACT FROM AUTHOR]

Before periapical surgery in the mandibular posterior teeth is performed, the thicknesses of the buccal alveolar bone wall and buccolingual root might be a critical issue. This study aimed to assess the anatomical structure of the posterior region of the mandible in Taiwanese individuals using cone-beam computed tomography (CBCT). The CBCT images of 96 Taiwanese individuals (51 male and 45 female), which included 192 mandibular first molars and 192 mandibular second molars, were imported into medical imaging software to measure the buccal alveolar bone thickness and buccolingual root thickness at 3 mm above the root apex. Statistical analysis was conducted to examine the impact of tooth position, gender, and age on the anatomical position of mandibular molars. The buccal alveolar bone thickness at 3 mm above the root apex of the mandibular second molar demonstrates a significantly higher value when compared to that of the first molar. Nonetheless, concerning the buccolingual root thickness, no significant differences were observed between these two teeth. In addition, the buccal alveolar bone thickness and buccolingual root thickness at 3 mm above the root apex may not be influenced by gender and age. The anatomical structures of the posterior region of the mandible in Taiwanese individuals exhibited variations between the mandibular first and second molars. However, these differences were not influenced by gender or age. [ABSTRACT FROM AUTHOR]

Awake bruxism is an understudied manifestation of frontotemporal dementia, yet awake bruxism can have fatal consequences in the aging population. This report presents a patient suffering from awake bruxism associated with frontotemporal dementia being treated with a mouthguard, which ultimately becomes lodged in her posterior oropharynx leading to asphyxiation. The case highlights the need for investigation into the occurrence and treatment of awake bruxism among patients with dementia, and the unique risk-benefit analysis that must be performed to develop proper treatment plans for patients with dementia. [ABSTRACT FROM AUTHOR]

• Laser bending process of perorated sheets is performed experimentally. • Effects of laser output power, laser scanning speed and number of irradiations on the bending angle are examined. • Bending angle of laser bent perforated sheet is increased with increasing in the laser output power and number of irradiations. • With increasing the laser scanning speed, the bending angle of bent sheet is decreased. • Optimization of input variables for achieving the maximum value of bending angle is performed. In this work, the laser bending process of perorated sheets is performed experimentally using a CO2 laser machine with maximum power of 120 W. Perforated sheets made of stainless steel 304 with a thickness of 2 mm are irradiated by laser beam in order to bend along a straight line. The effects of LOP (90–114 W), laser scanning speed (1–3 mm/s) and number of irradiations (10–20) on the bending angle of laser bent perforated sheets are examined using design of experiments based on response surface methodology. It is concluded from the obtained results that the bending angle of laser bent perforated sheet is increased with increasing in the laser output power and number of irradiations. In addition, it is proved that with increasing the laser scanning speed, the bending angle of bent sheet is decreased. Also, optimization of input variables shows that for achieving the maximum value of bending angle in laser bent perforated sheet the laser output power, laser scanning speed and number of irradiations should be adjusted as 114 Watts, 1 mm/s and 20, respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to outline the characteristics of severe trauma-induced oro-maxillofacial defects and explore the application of microsurgical reconstruction of these defects by selecting appropriate free vascularised composite tissue flaps. A retrospective analysis was performed in 11 cases with severe trauma-induced oromaxillofacial defects from 2005 to 2018, All cases were reconstructed with free vascularised composite flaps using a supermicro-surgical/micro-surgical and digital technology. This study consisted of 11 patients (8 men, 3 women) with a median age (range) of 28 (6–64) years. Patients with long-standing trauma experienced severe scars and displacements. The trauma-induced oro-maxillofacial defects ranged in size from 4.0 × 5.0 cm2 to 7 × 15 cm2. Six radial forearm flaps, three fibular osteocutaneous flaps, a lateral thoracic flap, and an anterolateral thigh flap were harvested individually. All patients were treated effectively and followed up for over two years, with a 100% survival rate of these free vascularised composite tissue flaps. No uncontrollable complications occurred, and all patients were satisfied with the postoperative shape and function. The trauma-induced oro-maxillofacial defects display unique features, and microsurgical techniques play an important role in the reconstruction of shapes and function. In addition, some patients may need multi-stage surgeries to attain aesthetic refinement. [ABSTRACT FROM AUTHOR]

The complexity and time requirements for contemporary ART laboratory activities has increased compared with traditional cycle requirements from 9 personnel hours, to 20 hours for completion [1]. Concurrently, the emergence of machines for data capturing and API integrations have appeared yet the two are rarely utilized in combination. Instead, labs are encouraged to consider admin support to complete important, time-consuming tasks which do not require specific training. This is labour intensive often with double data entry, prone to human error and costly. An alternative is to implement the promise of this digital ecosystem utilizing API's and automatic data capture. The study involved six fertility centres in the UK, Australia, and the US, utilizing Embie's clinic management software integrated with Cooper's RI Witness, Vitrolife's Embryoscope, and Fairtility's CHLOE EQ. a comprehensive analysis of current procedures in fertility centers across three continents was conducted. Manual data entry vs machines and API data points available in the market was modeled. This involved interviews with embryologists, data mapping, exploring API endpoints and gathering feedback for a user interface meant to improve the process as well as an analysis of time saved per cycle when comparing manual vs automatic data entry/capture. The siloed data systems showed a moderate improvement, averaging 209 manual entry points. However, the disconnected nature of these systems still posed challenges in data consistency and effective communication between different platforms, leading to duplicate data entry. A fully integrated process, demonstrated a drastic reduction, with an average of just 18 manual data entry points which was performed in real time e.g. the number of eggs collected was inputted into the RI witness system at the end of the procedure and pushed into the EMR. This minimized the potential for human error, streamlined workflow, improved overall efficiency and accuracy. This study highlights the transformative potential of digital integration in ART laboratories, suggesting significant improvements in efficiency and accuracy. It emphasizes the need for centers to transition from traditional methods like pen-and-paper, Excel sheets, or outdated electronic medical records systems to adopting newer, more advanced technologies. [ABSTRACT FROM AUTHOR]

Background: It is widely accepted that mouthguards are effective for injury protection in sports. However, findings on the effects of mouthguards in strength and power production remains controversial. Therefore, the aim of this study was to determine whether controlled-mandible position mouthguards influence strength and power production in well trained athletes.Methods: Twenty-two male amateur rugby players (25 ± 3.84 yrs; 1.92 ± 0.07 m; 93.91 ± 11.99 kg) volunteered for this study. Every participant performed an 1RM bench press test (113.20 ± 16.83 kg) to determine his maximal strength. In a randomized order, a ballistic bench press using 40% of the obtained 1RM (44.93 ± 6.76 Kg) was performed in a guided bar attached to a linear position transducer (LPT) for the following conditions: a) no mouthguard (CON); b) controlled mouthguard (MCM - jaw in centric relation); c) non-controlled mouthguard (NCM) and d) occlusal splint (OS). Vertical dimension of occlusion was also assessed for each of the testing conditions.Results: Athletes using a controlled mouthguard demonstrate a significant (p < 0.05) higher peak acceleration and peak force than those using no mouthguard. Additionally, when analysing the results of vertical dimension of occlusion, a significant difference (p < 0.05) was observed between controlled mouthguard and the other tested conditions.Conclusion: Controlled mouthguards enhance peak force and peak acceleration in the ballistic bench press exercise without negatively affecting any other measure assessed in this study. We speculate that this is possibly due to an increased stability of temporomandibular joint. [ABSTRACT FROM AUTHOR]

The detonation wave in a rotating detonation engine is highly adaptable to the incoming flow, making the wave easier to control. In this study, a numerical simulation method is used to analyze the working process and flow field structure of a rotating detonation model engine with dual cavity injection of an H 2 /air mixture by controlling the injection pressure ratio of the dual cavity and the number of detonation wave heads. It is found that the rotating detonation engine offers the possibility to control the thrust vector with two different modes. The first is a one-cycle alternate control mode with a small injection pressure ratio. Here two deflections occur in different directions occur across one detonation wave propagation cycle, but the overall deflection direction is in the low-pressure region. The second is a one-way control mode, with a large injection pressure ratio, and the deflection direction towards the low-pressure region. For the multi wave-mode, it belongs to one-way control mode because of constant deflection direction in the low-pressure area. From the perspective of thrust distribution along the circumference, the one-way control strategy satisfies the ability of a rotating detonation thrust vector control. • RDE theoretically owns the ability of the thrust vector control with two modes. • Analyze the specific impulse and thrust of the rotating detonation engine during the processes of the thrust vector control. • One-cycle alternate and one-way control modes have different processes, but the latter is more suitable for RDE applications. • Numerical simulation with dual cavity injection was adopted to analyze the TVC working process and flow field structure. [ABSTRACT FROM AUTHOR]

Custom-made mouthguards (MGs) are strongly recommended for athletes during sports activities to prevent dental injuries. Athletes undergoing orthodontic treatment and wearing brackets require specially designed MGs for better protection and to create more space that will not hinder the planned orthodontic tooth movement. The purpose of this study was to fabricate effective, specially designed, custom-made MGs for patients or athletes with ongoing orthodontic treatment and to evaluate the shock absorption abilities of these MGs by an in vitro comparison of three different designs. Three different types of specially designed, double-layered MGs, (i) creating inter bracket space inside the MG, (ii) embedding silicon wax inside the MG, and (iii) creating a buffer space with additional hard insertion, were fabricated from a simulated bracket attached model. Impact test was performed using a free-falling object on a vertical rod, and the strain-gauge system was used to assess the strain on the dentition with the MGs for the comparison of the shock absorption abilities of the three types. Analysis of variance at a significance level of 5% and multiple comparisons were performed for statistical analysis. The strains on the dentition with the MG creating buffer space with hard insertion were significantly lower than those with the other two types of MG (P < 0.001). Insertion of a hard material and ensuring buffer space between the MG and the teeth and/or appliance was more effective than other methods of fabricating custom-made MGs to prevent sports-related traumatic dental injuries in athletes undergoing orthodontic treatment. [ABSTRACT FROM AUTHOR]

A single-step reduction and patterning technique that involves high-pulse nanosecond fiber laser irradiation was used to reduce graphene oxide films (GOFs) for use in ceramic-based heaters. Laser reduction of GOFs was performed at a laser power, scan speed, pulse repetition frequency, and laser scan pitch of 2.2–4.1 W, 150–500 mm/s, 750 kHz, and 10 μm, respectively. The optimal intensity ratios of the D to G band (R D/G) and the 2D to G band (R 2D/G) of reduced GOFs (RGOFs), obtained from Raman spectra, were 0.251 and 0.587, respectively. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that oxygen-containing functional groups in RGOFs coated onto ceramic substrates were removed by increasing the average laser power and decreasing the laser scanning speed. Moreover, the typical RGOFs exhibited a lowest sheet resistance of 22.75 ± 2.75 Ω/□, which was achieved with an average laser power and scan speed of 3.35 W and 300 mm/s, respectively. The highest temperature of the typical laser-patterned RGOFs was approximately 123.3 °C, which occurred when the RGOFs were produced using a laser power, scan speed, and applied direct current voltage of 3.27 W, 200 mm/s, and 10 V, respectively. • Fiber laser reduction and patterning approach was used to fabricate rGO heaters. • Fiber laser reduction parameters involved various laser powers and scan speeds. • The optimal I D /I G and I 2D /I G of rGO films were 0.251 and 0.587, respectively. • The typical rGO films had the lowest sheet resistance of 22.75 ± 2.75 Ω/sq. • The maximum heating temperature of typical laser-patterned rGO films was 123.3 °C. [ABSTRACT FROM AUTHOR]

Objective: To assess the efficacy and safety of a covering method using polyglycolic acid (PGA) sheets and fibrin glue in preventing laryngopharyngeal bleeding after endoscopic laryngopharyngeal surgery (ELPS) combined with endoscopic submucosal dissection (ESD).Methods: Twenty-one patients who underwent ELPS combined with ESD (28 resected pharyngeal carcinomas) were retrospectively evaluated. After completing ELPS combined with ESD, fibrinogen was sprayed onto the ulcer. A PGA sheet cut into 5 × 5 mm pieces that fit the size of the ELPS-induced ulcer was then placed over the ulcer and fixed in place with a fibrin glue comprising thrombin.Results: The resection procedure was performed for all lesions. The median long diameter of the resected specimen was 36 mm. The rate of a resected specimen diameter >30 mm, use of anticoagulant/platelet, and macroscopic classification 0-Ⅱa were 68% (19/28), 19% (5/28), and 36% (10/28), respectively. The median time required to cover ELPS-induced ulcers using PGA sheets and fibrin glue was 10 min (range: 3-22 min). No post-ELPS bleeding, subcutaneous emphysema, or aspiration pneumonia (0/28) was observed.Conclusion: The covering method using PGA sheets and fibrin glue for ELPS-induced ulcers is considered to be sufficiently safe and effective in preventing post-ELPS laryngopharyngeal bleeding. This method could be useful in preventing post-ELPS bleeding in patients with head and neck cancer. [ABSTRACT FROM AUTHOR]

• A novel multiscale topology optimization method is proposed for designing asymmetric porous sandwich structures. • Multi-material sandwich structures are topologically optimized using the proposed method. • The thickness and material of two face sheets and the configuration of composite cores are simultaneously optimized. • Parametric level set method and alternating active-phase method are adopted. • Several 2D and 3D numerical examples are investigated and compared. Compared with conventional symmetric sandwich structure with identical face sheets and single-material core, asymmetric porous sandwich structures (APSSs), which are composed of unidentical face sheets and composite core, usually take better advantage of all materials and provide superior bending stiffness. However, current studies regarding the APSSs are mainly analytical- and experimental-based methods with predefined face sheet thicknesses and core configurations, which greatly confines the potential loading capacity of sandwich structures. This paper develops a multiscale topology optimization method for the multi-material APSSs, which can realize the designs of the thickness and material of two face sheets at macroscale as well as the configuration of composite cores at microscale for minimizing structural compliance. Firstly, at macroscale, a multi-material variable thickness sheet method integrated with an alternating active-phase algorithm are employed to optimize the thickness and material of two solid face sheets. Then, at microscale, a difference-set-based multi-material level set (DS-MMLS) model is applied to represent the topology of each material phase within sandwich core, and their topological evolution can be readily achieved by using a parametric level set method also combined with the alternating active phase algorithm. Several 2D and 3D numerical examples are provided to show the effectiveness and advantages of the proposed method. The results indicate that compliances of the optimized APSSs show superior advantages over some conventional sandwich structures with predefined design features. [ABSTRACT FROM AUTHOR]

Background: The importance of mouthguards for handball players has been proven however, most players are reluctant to use it. The impact on physical capacity is assessed heterogeneously in the literature. This study aimed to investigate the influence of custom-made mouthguards (CMGs) under handball specific stress.Methods: This randomized crossover study used data from 15 youth professional handball players (age 17.0 ±0.5 years, weight 85.1±8.0 kg and height 191.2±6.9 cm) who performed a validated handball specific course and a lung function test. Pulmonary (spirometry), metabolic (blood lactate), and cortisol parameters were observed using a normal custom-made mouthguard without (nCMG) and with respiratory channels (CMGvent) in comparison to no mouthguard (Co).Results: In resting spirometry, no differences in the parameter peak flow were observed using the CMGvent (9.57±1.59 l·s-1) and nCMG (9.17±1.03 l·s-1) in comparison to the Co (9.38±1.26 l·s-1). Under maximum stress, there were no differences in ventilation using CMGvent (151.2±15.64 L ·min-1), nCMG (148.6±12.51 l·min-1), and without mouthguard (145.8±14.32 l·min-1). Similar oxygen uptake was observed when using a CMGvent (45.51±4.14 L ·min-1·kg-1), nCMG (45.50±5.06 ml·min-1 ·kg-1), and without CMG (Co 43.90±4.02 mL ·min-1). The parameters of HR (CMGvent 185.2±11.63 bpm vs. Co 179.4±13.24 bpm p=0.46, nCMG 178.2±11.54 bpm vs. Co p=0.97; CMGvent vs. nCMG p=0.08) and in the blood lactate values (CMGvent: 9.66±2.3 mmol·l-1 vs. Co 9.07±2.1 mmol·l-1 p=0.63; nCMG 9.39±2.8 mmol·l-1 vs. Co p=0.87; CMGvent vs. nCMG p=0.91) displayed no differences. The cortisol production under stress showed no differences in the performance with the CMGvent (1.78±3.58 ng/ml), nCMG (0.74±4.52 ng/mL), and in the procedure without mouthguard (0.25. ±5.01 ng/ml).Conclusion: The results showed that under stress, there were no differences in the cortisol, ventilation, cardiac, and metabolic responses for all three conditions. Finally, the study shows that the use of a custom-made mouthguard does not negatively affect handball specific performance. Due to the preventive aspect of the mouthguard, the use of a custom-made mouthguard in handball is strongly recommended. [ABSTRACT FROM AUTHOR]

The low-pressure limit rate constant k 1 , 0 of the reaction N 2 O + M ⇄ N 2 + O + M was measured in shock-heated mixtures of 0.2% N 2 O/Ar using 4.56-µm laser absorption of N 2 O in the temperature range 1546–2476 K near 1.3 atm. Modeling the N 2 O profiles with a detailed kinetic analysis, which considered non-ideal pressure variations, provided k 1 , 0 values that were best fit by the expression k 1 , 0 = 1.01 × 10 15 exp (− 30 , 050 / T) , with k 1 , 0 in cm3mol–1s–1 and T in K. Estimated k 1 , 0 uncertainties at 1546, 1821, and 2230 K were respectively 13.0%, 8.9%, and 9.0%. By combining the results of the present study with previous low-temperature data measured in flow/static reactors, the best fit over the temperature range 850–2500 K was determined to be (k 1 , 0 in cm3mol–1s–1, T in K) (R1) k 1 , 0 = (1.04 ± 0.04 × 10 15) exp [ (− 30 , 098 ± 90) / T ]. This is the first study of k 1 , 0 using N 2 O infrared laser absorption. Through the high signal-to-noise ratios of the experimental N 2 O profiles and careful consideration of d P / d t effects, this k 1 , 0 determination is in excellent agreement with the large body of historical k 1 , 0 data but demonstrates significantly less scatter than all previous measurements. [ABSTRACT FROM AUTHOR]

The Objective of this study was to present the clinical application of paraffin wax for creating customized mouthpieces for head and neck cancer and boluses for skin cancer in radiotherapy at FV Hospital. Clinical cases were utilized to demonstrate the application of paraffin wax in creating custom-made devices. The custom-made mouthpieces used paraffin wax and a Guedel airway cannula to obtain precise intraoral impressions. The paraffin wax was applied to all areas of the oral cavity to ensure accurate impressions of the teeth, tongue, and other intraoral tissues. Similarly, for the custom-made bolus for skin cancer, impressions of the periauricular area, including the external auditory canal, parotid bed, and auricle, were obtained. The fabrication process took approximately 15-20 minutes. Using custom-made mouthpieces for head and neck cancer and boluses for skin cancer demonstrated promising RESULTS: in reducing radiation doses to organs at risk during intensity-modulated radiotherapy. No patients experienced grade 3 or above oral mucositis, taste dysfunction, or xerostomia during or after radiotherapy. Additionally, the custom-made bolus for skin cancer of the auricle provided a better fit than a commercial bolus, effectively enhancing the surface and canal doses for adequate treatment. Using paraffin wax to create customized mouthpieces for head and neck cancer and boluses for skin cancer improved anatomical fit and enhanced patient comfort, leading to more precise treatment planning and improved setup and positioning accuracy. These custom-made devices are easy to fabricate and demonstrate clinical usefulness. [ABSTRACT FROM AUTHOR]

Margin negative resection in pancreatic cancer remains the only curative option but is challenging, especially with the retroperitoneal margin. Intraoperative radiation therapy (IORT) can improve rates of local control but requires specially designed facilities and equipment. This retrospective review describes initial results of a novel implantable mesh of uni-directional low dose rate (LDR) Pd-103 sources (sheet) used to deliver a focal margin-directed high-dose boost in patients with concern for close or positive margins. Eleven consecutive patients from a single institution with resectable or borderline resectable pancreatic cancer with concern for positive margins were selected for sheet placement and retrospectively reviewed. Procedural outcomes, including the time to implant the device and complications, and clinical outcomes, including survival and patterns of failure, are reported. A dosimetric comparison of the LDR sheet with hypothetical stereotactic body radiotherapy (SBRT) boost is reported. One patient had a resectable disease, and 10 patients had a borderline resectable disease and underwent neoadjuvant treatment. Sheet placement added 15 min to procedural time with no procedural or sheet-related complications. At a median follow up of 13 months, 64% (n = 7) of patients are alive and 55% (n = 6) are disease-free. Compared to a hypothetical SBRT boost, the LDR sheet delivered a negligible dose to kidneys, liver, and spinal cord with a 50% reduction in max dose to the small bowel. This is the first report of the use of an implantable uni-directional LDR brachytherapy sheet in patients with resected pancreatic cancer with concern for margin clearance, with no associated toxicity and favorable clinical outcomes. [ABSTRACT FROM AUTHOR]

Intracranial recordings are integral to evaluating patients with pharmacoresistant epilepsy whom noninvasive testing fails to localize seizure focus. Although stereo-electroencephalography is the preferred method of intracranial recordings in most centers, subdural electrode (SDE) implantation is necessary in selected cases. To identify imaging correlates that predict SDE complications (extra-axial fluid collections [EFCs]), and determine if modifications that diminish stiffness of electrode sheets reduce complications. A prospective epilepsy surgery database was used to identify adults undergoing craniotomy for SDE implantation over a 14-year period. EFCs and midline shift were measured via magnetic resonance imaging and computed tomography imaging. Correlation analyses and multivariable logistic regression explored associations between use of conformal arrays, serial order of patients, previous ipsilateral intracranial surgery, midline shift, number of SDEs, and neurologic complications. A total of 111 consecutive patients (59 female) underwent 117 craniotomies (mean, 115 electrode contacts) for SDE implantation. There were 8 surgical complications, 3 in the first 17 (17.7%). and 5 (after electrode modifications) in a subsequent 100 craniotomies (5.0%). We noted an increase in electrode numbers implanted over time (P < 0.001) and decreased midline shift with conformal grids (ρ = – 0.32; P < 0.001). A multivariable regression showed that midline shift correlated with complications (odds ratio, 2.32; 95% confidence interval, 1.12–4.78; P = 0.023). Hemorrhagic complications after SDE implantation are difficult to detect because of artifact from electrodes, but predictable by prominent midline shift (>4 mm). Risks inherent to SDE implantation may be minimized using conformal grids. With symptomatic EFCs, a single electrode cable exit site allows hematoma evacuation without terminating intracranial recordings. [ABSTRACT FROM AUTHOR]

The objective was to explore how clinically relevant machining process and heat treatment influence damage accumulation and strength degradation in lithium silicate-based glass ceramics machined in the fully crystallized state. A commercial zirconia-reinforced lithium silicate (ZLS) glass ceramic with a fully developed microstructure (Celtra® Duo) was studied. Disk-shaped specimens (nominal 10 mm diameter and 1 mm thickness) were fabricated either using a CAD-CAM process, creating a clinically relevant dental restoration surface, or were sectioned from water-jet cut cylindrical blocks with their critical surfaces consistently polished. Bi-axial flexure strength (BFS) was determined in a ball-on-ring configuration, and fractographic analysis was performed on failed specimens. XRD, AFM and SEM measurements were conducted before and after heat treatment. For each sample group, BFS was correlated with surface roughness. A two-way ANOVA and post-hoc Tukey tests were used to determine differences in BFS between machining and heat treatment groups (ɑ = 0.05). A two-way ANOVA demonstrated that BFS was influenced by fabrication route (p < 0.01) with CAD-CAM specimens exhibiting significantly lower mean BFS. A factorial interaction was observed between heat treatment and machining route (p < 0.01), where a significant strengthening effect of post-manufacture heat treatment was noted for CAD-CAM specimens but not sectioned and polished samples. CAD-CAM specimens exhibited sub-surface lateral cracks alongside radial cracks near fracture origin which were not observed for polished specimens. BFS did not correlate with surface roughness for polished specimens, and no change in microstructure was detectable by XRD following heat treatment. The mechanical properties of the ZLS ceramic material studied were highly sensitive to the initial surface defect integral associated with manufacturing route and order of operations. CAD-CAM manufacturing procedures result in significant strength-limiting damage which is likely to influence restoration performance; however, this can be partially mitigated by post-machining heat treatment. [ABSTRACT FROM AUTHOR]

Felsic collapse calderas pose a hazard to our society, thus detailed knowledge of collapse mechanisms and behavior of eruptive products could help us to better understand the active calderas. We present a model of the eruption and collapse of Late Carboniferous Tharandter Wald Caldera (Variscan Bohemian Massif) based on field mapping and a magnetic multi-fabric approach. We investigate intra-caldera rhyolitic ignimbrites using a combination of conventional in-phase and relatively new out-of-phase anisotropy of magnetic susceptibility, along with the anisotropy of anhysteretic remanent magnetization. A two-stage caldera evolution model is proposed. (1) The high-energetic and high-temperature ignimbrites filled the paleo-valleys to form a thick ignimbrite sheet with welded to rheomorphosed central portion. Concurrently, eruptions emptied the source magma chamber triggering the piston caldera collapse. (2) The subsidence caused a monoclinal ductile bending of the still-hot and ignimbrite sheet around the caldera rim towards its center. Caldera activity was terminated by the emplacement of subvolcanic ring and radial dikes associated with hydrothermal activity. The latter likely induced abundant magneto-mineralogical alteration and formed composite fabrics. Hence, the application of the multi-fabric approach may serve as a useful tool to extrapolate reliable geodynamic proxies from the magnetic fabric of old, eroded, or altered caldera ignimbrites. [ABSTRACT FROM AUTHOR]

Instrumented mouthguard (iMG) sensors have been developed to measure sports head acceleration events (HAE) in brain injury research. Laboratory validation studies show that effective coupling of iMGs with the human skull is crucial for accurate head kinematics measurements. However, iMG-skull coupling has not been investigated in on-field sports settings. The objective of this study was to assess on-field iMG coupling using infrared proximity sensing and to investigate coupling effects on kinematics signal characteristics. Forty-two university-level men's ice hockey (n = 21) and women's rugby (n = 21) athletes participated in the study, wearing iMGs during 6–7 month in-season periods. Proximity data classified video-verified HAE recordings into four main iMG coupling categories: coupled (on-teeth), decoupling (on-teeth to off-teeth), recoupling (off-teeth to on-teeth) and decoupled (off-teeth). Poorly-coupled HAEs showed significantly higher peak angular acceleration amplitudes and greater signal power in medium–high frequency bands compared with well-coupled HAEs, indicating potential iMG movements independent of the skull. Further, even video-verified true positives included poorly-coupled HAEs, and iMG coupling patterns varied between the men's hockey and women's rugby teams. Our findings show the potential of using proximity sensing in iMGs to identify poorly-coupled HAEs. Utilizing this data screening process in conjunction with video review may mitigate a key source of sensor noise and enhance the overall quality of on-field sports HAE datasets. [ABSTRACT FROM AUTHOR]

In this research, a new flexible multi-point incremental sheet forming process with multi-layer sheets (F-MPIF-MLS) was proposed. The novelty of this new forming process is demonstrated by two specific aspects of contribution. The first is the development of a new flexible multi-point die system to replace the conventional multi-point die, in which the multi-point pins are in contact with and provide support to the blank sheet from the start to the end of the forming operation. The second is the use of multi-layer sheets, which allows the target blank sheet to be deformed without clamping constraints. The new F-MPIF-MLS process clearly shows the benefits of overcoming the limitations of excessive sheet thinning and poor surface finish of the existing conventional multi-point incremental sheet forming (MPIF) process. A detailed comparative investigation into the new F-MPIF-MLS and the conventional MPIF processes is conducted through experimental testing and finite element (FE) simulation. The results show a noticeable reduction of wrinkling by using the new flexible multi-point die over the conventional multi-point die system with multi-layer sheets to form a dome shape. Moreover, in using the new F-MPIF-MLS process, the maximum thickness reduction is significantly reduced from 35% to 5% as compared to the conventional MPIF process to achieve a more uniform thickness distribution of the formed part. • A new flexible multi-point incremental sheet forming process with multi-layer sheets (F-MPIF-MLS). • Experimental validation and FE simulation of the new F-MPIF-MLS process as compared to conventional MPIF process. • Demonstration of significantly reduced sheet thinning and occurrence of wrinkling [ABSTRACT FROM AUTHOR]

The objective of this article is to investigate numerically the radiative structure of methane, ethylene and acetylene lab-scale jet flames ranging from the transitional to the momentum-driven regimes. The numerical model involves a hybrid flamelet/transported PDF method coupled to an acetylene-benzene soot production model and a Wide-Band Correleted-K gas radiation model. Model predictions in terms of mean and rms soot volume fraction and temperature, integrated soot volume fraction and radiant fraction are in reasonable agreement with the available experimental data. In particular, the model reproduces quantitatively the decrease in radiant fraction observed as the flow becomes momentum driven. This behavior results mainly from two mechanisms: (i) an increase in flame self-absorption due to an enhancement in flame volume and (ii) for the ethylene and acetylene flames a reduction in the soot emission per unit flame volume owing to a strong decrease in soot production. In addition, for a given fuel, gas emission per unit flame volume remains approximatively constant as the exit strain rate increases whereas the soot emission per unit flame volume and the characteristic soot volume fraction scale with the Kolmogorov time scale. It was also found that competitive mechanisms govern the effects of Turbulence-Radiation Interaction (TRI) on radiant fraction. Enhancement mechanisms are due to gas emission TRI and temperature self-correlation effects on soot emission whereas inhibiting mechanisms results from the negative correlation between soot volume fraction and temperature. Enhancement mechanisms dominate in weakly sooting methane flames and taking TRI into account increases the radiant fraction. On the other hand, inhibiting mechanisms become significant in moderately and highly sooting fuels, with their importance increasing with both the fuel sooting propensity and the Reynolds number. For flames dominated by soot radiation, the inhibiting mechanisms prevail and taking TRI into account reduces the radiant fraction. [ABSTRACT FROM AUTHOR]

The donor lenticule insertion techniques play a crucial role in outcomes following descemet stripping endothelial keratoplasty (DSEK) and the current study is aimed to compare two of the commonly performed donor lenticule insertion techniques in DSEK. Descemet stripping endothelial keratoplasty was performed in 48 eyes of 48 patients at two tertiary eye care centers from January 2014 to December 2016. At one center (Group 1), 26 patients had Sheets glide-assisted lenticule insertion whereas at other center (Group 2), 22 patients had Busin glide-assisted insertion of donor lenticule. Best corrected visual acuity (BCVA), manifest spherical equivalent, manifest cylinder, endothelial cell density (ECD) and percentage of endothelial cell loss (ECL) were compared between the two groups at 6 months after DSEK. In addition, intraopertaive and postoperative complications were also compared. At 6 months after DSEK, an insignificant difference was observed in BCVA [Group 1: 0.48 logarithm of the minimum angle of resolution (log MAR); Group 2: 0.50 log MAR (p = 0.74)], mean manifest spherical equivalent [Group 1: 0.64 diopter (D); Group 2: 0.59 D (p = 0.74)], mean manifest cylinder [Group 1: 1.35 D; Group 2: 1.32 D (p = 0.92)] and mean ECL [Group 1: 26.75%; Group 2: 28.76 (p = 0.44)] between the two groups. In addition, the rate of complications is similar between the two groups. Both Sheets glide-assisted and Busin glide-assisted donor lenticule insertion techniques are associated with similar surgical outcomes after DSEK. [ABSTRACT FROM AUTHOR]

A self-supporting sandwich panel façade system under fire is studied. First, a thermomechanical FE model, which comprises the complete façade system, and incorporates material degradation and geometrical nonlinear behaviour except for the insulation material and connections, is loaded by a fire temperature curve. Eurocode design rules then predict the screw connections of a sandwich panel will fail in shear. Secondly, an existing programme, FDS-2-Abaqus, is extended to allow its two-way coupled analyses, in which CFD fire simulations are updated for changes in the thermomechanical FE model, to be applicable to the façade system. Again, these simulations show the shear failure of the screws. Parameter studies show differences in system behaviour for improved screw properties; a fuel-controlled vs. ventilation-controlled fire; and different panel thicknesses. Interestingly, as thermal bowing of the panel retards screw failure, and thicker sandwich panels bow less than thinner panels, thicker façade panels will decrease failure time. This and other insights obtained, and the predicted failure of two tiny but critical screws within 80 s, as compared to 150 min lasting sandwich panels in standard fire tests, stresses the need to study complete systems under realistic fires, rather than to study individual components in standard fire tests. Future research will focus on detailed FE models of the connections; full-scale fire experiments; CFD temperature measurement points at the façade outside; detailed modelling of the insulation; and the effects of high temperature creep. • Sandwich façade fire resistance studied fundamentally, not via tests or codes. • For FEM, failure modes for panels, facade openings, and connections (ambient). • Temperature dependent properties for steel plates, columns, and sections. • Façades under realistic fires should be studied, not their components in tests. [ABSTRACT FROM AUTHOR]

A mouthguard is a piece of equipment worn in sports worldwide to greatly reduce the chance of orodental injuries. This work uses a newly developed method for testing and analysing mouthguards subjected to high impact energies of up to 100 J. This method allows investigation and comparison between the use of additive manufacturing, and current best mouthguard manufacturing technology of thermoforming with Ethylene-vinyl acetate (EVA). The impact experiments are conducted using a drop tower and high-speed images are captured for the further analysis. Important physical parameters such as peak force, impulse and dissipated energy in the mouthguard are determined. The results revealed that the additively manufactured mouthguards made from Arnitel® ID 2045 lead to a peak force and impulse of impact that is on average 10% and 25% lower, respectively, than that experienced when using the EVA mouthguard. A lower peak force and impulse is preferred as it reduces the chance of an orodental injury occurring. The research shows that previously mouthguards have been tested at impact energies far lower than those experienced in impact prone sports such as field hockey. When using impacts with higher energies, the findings show that additive manufacturing provides a viable technology for manufacturing mouthguards, which offers many new benefits. • Additive manufacturing provides a way for manufacturing mouthguards for improved mechanical performance in high impact prone sport activities. • Peak force and maximum impulse of Arnitel®3D-printed mouthguards are slightly lower than those of thermoformed EVA ones at impacts up to 100 J. • Impact tests reveal that conventionally thermoformed EVA mouthguards are more affected by fatigue than the Arnitel®3D-printed ones. [ABSTRACT FROM AUTHOR]

The rapid development of nanoscale surface modification technology has led to the development of superhydrophilic, superhydrophobic, and slippery liquid-infused porous surfaces (SLIPS) in recent decades. These surfaces have excellent self-cleaning and anti-contamination performance, and many studies have reported their industrial applications. Industrial and modern medical applications of titanium are rapidly expanding owing to its advantages of chemical stability, high mechanical strength, stable corrosion resistance, and biocompatibility; however, performing surface modification of titanium remains challenging. In this study, superhydrophilic, superhydrophobic, and SLIPS were fabricated on titanium using a simple surface fabrication method, and their wettabilities were analyzed and compared. Furthermore, we succeeded in applying the method used in this study to bulky and complex objects. Chemical and physical analyses were performed to confirm the fabrication, wettability properties, and nanostructures of the modified surfaces. The simple fabrication method presented a significant advancement as there are no limitations in its application to large areas, complex shapes, or mass production, unlike existing titanium wettability modification methods. [Display omitted] • Simple TiAl6V4 nanostructured surface fabrication by immersion method is developed. • Nanostructure growth of TiAl6V4 surface according to reaction time is analyzed. • Various wettability modifications are performed on TiAl6V4. • The method is applicable for regardless of the size and the shape of the surface. [ABSTRACT FROM AUTHOR]

• Fatigue analyses for Cu LsWd LP-S specimens were conducted by experiments and FEA. • Failure modes & fracture mechanisms of Cu LsWds were studied by micrographs. • 2D plane strain FE models of Cu LsWds were developed to derive GSIFs and LSIFs. • Two fatigue models consisted of GSIFs, LSIFs and Paris law were developed. • Predicted fatigue data of Cu LsWds matched the general trends of experimental data. This study experimentally and numerically investigated the fatigue response of laser-welded (LW) lap-shear samples in copper (Cu) sheets of dissimilar thicknesses. Fatigue tests were first conducted, and the resulting fatigue data and failure modes were recorded. To investigate the failure processes and mechanisms, microscopic examinations, including microhardness tests for Cu LWs, were conducted before and after the failure. The experimental results showed the interfacial failure under high-load-range and low-load-range conditions and the top sheet separation under median-load-range conditions. Next, finite element analyses for LW lap-shear samples were conducted to calculate the global stress intensity factors (GSIFs) and local stress intensity factors (LSIFs) for interfacial and kinked cracks, respectively. The GSIFs, LSIFs, and Paris law were further used to derive the two fatigue models to analyze the evolution of interfacial and kinked cracks, respectively. Finally, two fatigue models estimated a series of fatigue lives that matched the general trends of experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Wide-angle microwave attenuation performance in both TE and TM modes could be achieved by designed 2D patterns. • The 2D patterning of magnetic composite sheets significantly enhances their TM mode performance, achieving over 20 dB attenuation at oblique incident angles of up to 40°. • The achieved polarization-insensitive performance comes with a weight reduction of approximately 16%. Magnetic composite sheets loaded with carbonyl iron powders (CIP) are widely used due to their high-efficiency microwave attenuation at very thin thickness because of their outstanding permeability and magnetic loss. However, their performance varies dramatically at various incident angles and polarization modes, namely transverse electric (TE) and transverse magnetic (TM) modes. In this study, it is demonstrated that two-dimensional (2D) patterning could offer an effective solution for achieving wide-angle performance in both TE and TM modes. Different shapes of the 2D patterns (circles, hexagons, and cross-holes) are investigated and their dimensions are optimized through full-wave simulation. The consistent results with the experiment reveal that these 2D patterns with optimized dimensions could improve TM mode performance significantly to above 20 dB attenuation for an oblique incident angle up to about 40°, thanks to the resulted field resonance revealed by simulation. Due to the improved TM mode performance, the patterned composite sheet could exhibit almost identical high-efficiency attenuation in both modes, becoming polarization-insensitive. The performance improvement also comes with a ∼16% reduction in weight. Given these merits and the ease of fabrication, the low-profile and robust 2D patterned magnetic composite sheets could attract great attenuation in practical applications for wide-angle and polarization-insensitive microwave attenuation. [ABSTRACT FROM AUTHOR]

The novel junction (CoP/CSNSs) composed of pure-phase CoP nanoparticles in-situ growth on Co 3 (Si 2 O 5) 2 (OH) 4 nanosheets (CS) with advanced HER and OER electrocatalytic performance. [Display omitted] • CoP is in-situ grown on Co 3 (Si 2 O 5) 2 (OH) 2 as a prospective bifunctional catalyst. • The novel CoP/CSNSs junction achieves the cell voltage of 1.50 V at 10 mA cm−2. • Optimal electronic structure and adjacent active component boost water splitting. • Junction design benefit for develop silicate into multifunctional electrocatalyst. The development of promising bifunctional water splitting electrocatalysts through precise design of composition and structure is a challenging topic. In this work, a novel junction is developed consisting of pure-phase CoP nanoparticles in-situ grown on Co 3 (Si 2 O 5) 2 (OH) 4 nanosheets, denoted as CoP/CSNSs. Rely on the small adding Co2+ (0.1 mmol) in complex precursor, controllable synthesis of pure-phase CoP without impure phases is achieved, and the perfect nanosheet structure from support can be inherited, the CoP/CSNSs therefore shows the highest electrocatalytic performance for both HER and OER in 1.0 M KOH. Besides, the overall water splitting voltage of CoP/CSNSs(+/-) delivers 1.50 V at 10 mA cm−2, which outperforms that of the commercial Pt/C||RuO 2 system. The preferable bifunctional electrocatalytic performance benefits from the optimized electron state of the adjacent dual-active centers, such that surficial CoP contributes to the dissociation of H-OH bonds boosting the Volmer step of HER, and Co 3 (Si 2 O 5) 2 (OH) 4 support contributes to OH– adsorption facilitating the kinetics of OER. Meanwhile, the advanced nanosheet structure provides more accessible active centers and more efficient charge/mass transport highway. In this work, bifunctional metal silicate electrocatalyst for water dissociation is designed and fabricated for the first time. The simple and effective phase-modulation and structure-control is a promising strategy for continually exploitation of multifunctional metal silicate electrocatalysts. The development of low-cost and highly efficient metal silicate-based electrocatalysts may create new opportunities for future development of renewable energy conversion technologies. [ABSTRACT FROM AUTHOR]

• Conventional springback model works in micro bending using the surface layer model. • The model underestimates the channel height in microforming of parallel channels. • The transverse stress is found to play an important role. • An improved model was developed considering the transverse stress. • The shift distance of the neutral plane and channel height are better captured. To satisfy the higher accuracy requirement in the microforming of thin-walled structures, the springback behavior under miniaturizing dimensions need to be accurately predicted and controlled. However, as the feature size approaches the thickness in microforming, many assumptions in conventional springback model for macroforming are not valid making these models can hardly provide effective springback analysis in microforming. In the present work, the applicability of a springback analytical framework of conventional stretch-bending was first explored via bending tests of 0.1 mm-thick SS316L sheets under different holding conditions with a punch radius from 3 to 5 mm which is much greater than the thickness. The analytical springback angle results agree with the experimental ones with the maximum error of 4.2% for different punch radii, grain sizes and stretching forces conditions, indicating the correctness of the model. The model was further verified in the microforming of parallel channels with a fillet radius of 0.15 mm. Finite element simulations were conducted to obtain the stretching loads for each channel. However, a significant underestimation of the channel height after springback for over 15% was found especially for the middle channel. The transverse stress is revealed to be no longer neglectable due to the strong stretching load and the small die radius during the microforming of parallel channels, which substantially contributes to yielding, hardening and thickness reduction in the stretch-bending area. In addition, the uneven stretching also affects the springback angle and channel height, which is caused by the nonuniform plastic deformation of the adjacent channels. By incorporating the effects of the transverse stress and the non-uniform stretching loads, an improved springback model was developed for microforming of parallel channels in this work. The shift distance of the neutral plane is better estimated by the improved model than by the conventional one. The predictive heights by the improved model are also revealed to agree with the experimental ones during the microforming of parallel channels with a maximum error of less than 5%. [Display omitted] [ABSTRACT FROM AUTHOR]

• Surface degradation of Ge in vacuum on different laser conditions are showed. • The influences of processing parameter and material failure behavior are analyzed. • Mechanism in damage variation with laser ablation is compared in air and vacuum. • Damage mechanism contains thermal effect, plasma shock wave and mechanical stress. Laser-induced damage of germanium (Ge) sheets plays a key role to estimate the lifetime of optical components in the vacuum and space irradiation environment. However, the dependence between the degrees of laser-induced surface damage and nanosecond pulsed irradiation remains unclear for Ge sheet. Here, we investigate damage morphology and the growth characteristic of Ge sheets under different conditions and measure the laser-induced damage threshold (LIDT) in vacuum. Our results reveal that optical reflectivity of Ge in vacuum chamber falls 92% because of the defective sites on the damaged surface. The area, the depth and the size of the damage crater increase but the hillock height and the surrounding thermal diffuse area decrease along with the increase of vacuum degree. The thermal effect, the failure effect of plasma shock wave and the mechanical stress are analyzed to be the main mechanism in the laser damage. The combined experimental and theoretical work gives an insight into the change of surface damage and material failure behavior, hence broadens the potential applications of Ge sheets in areas of laser material manufacturing and laser processing. [ABSTRACT FROM AUTHOR]

We develop detachable “ Cavitas sensors” to apply to the human oral cavity for non-invasive monitoring of saliva glucose. A salivary biosensor incorporating Pt and Ag/AgCl electrodes on a mouthguard support with an enzyme membrane is developed and tested. Electrodes are formed on the polyethylene terephthalate glycol (PETG) surface of the mouthguard. The Pt working electrode is coated with a glucose oxidase (GOD) membrane. The biosensor seamlessly is integrated with a glucose sensor and a wireless measurement system. When investigating in-vitro performance, the biosensor exhibits a robust relationship between output current and glucose concentration. In artificial saliva composed of salts and proteins, the glucose sensor is capable of highly sensitive detection over a range of 5–1000 µmol/L of glucose, which encompasses the range of glucose concentrations found in human saliva. We demonstrate the ability of the sensor and wireless communication module to monitor saliva glucose in a phantom jaw imitating the structure of the human oral cavity. Stable and long-term real-time monitoring (exceeding 5 h) with the telemetry system is achieved. The mouthguard biosensor will be useful as a novel method for real-time non-invasive saliva glucose monitoring for better management of dental patients. [ABSTRACT FROM AUTHOR]

Objectives To better understand the effects of taste cues on delaying the attention shift from an external focus (dissociative) towards an internal focus (associative) as exercise intensity increases. Design A between subjects' experimental design with random assignment to three groups: taste (lemon-flavored mouth guards), placebo (unflavored mouth guards), or control group (no mouth guards) was used. Participants reported perceived exertion, affect (i.e., pleasantness and arousal), and attention allocation before, during, and after performing a weighted stepping task. Results Performing the task resulted in a gradual increase of perceived exertion, F (1.87, 74.89) = 63.05, p < .05, η p 2 = .61, along with a shift from dissociative to associative attention, F (2.17, 86.68) = 35.57, p < .05, η p 2 = .47 across all conditions. Additionally, participants reported feeling less pleasant and more aroused after task completion in all conditions. The lemon-flavored mouth guard failed to affect attention, F (4.33, 86.68) = 1.41, p = .23, η p 2 = .07, perceived exertion, F (3.74, 74.86) = .38, p = .81, η p 2 = .02, pleasantness, F (2, 40) = .126, p = .88, η p 2 = .01, and arousal, F (2, 40) = 2.40, p = .10, η p 2 = .10, differently than the other two conditions. Conclusions The study was one of the first to examine the effects of taste during an exertive task. Despite the non-significant effects of using a lemon-taste mouth guard on various cognitive variables (perception of exertion, attention allocation, pleasantness, and arousal), more scientific effort is needed to explore the effects of other tastes (e.g., sweet, bitter) and delivery methods (e.g., sprays, drops). [ABSTRACT FROM AUTHOR]

Wearable sensors are becoming increasingly popular for measuring head motions and detecting head impacts. Many sensors are worn on the skin or in headgear and can suffer from motion artifacts introduced by the compliance of soft tissue or decoupling of headgear from the skull. The instrumented mouthguard is designed to couple directly to the upper dentition, which is made of hard enamel and anchored in a bony socket by stiff ligaments. This gives the mouthguard superior coupling to the skull compared with other systems. However, multiple validation studies have yielded conflicting results with respect to the mouthguard׳s head kinematics measurement accuracy. Here, we demonstrate that imposing different constraints on the mandible (lower jaw) can alter mouthguard kinematic accuracy in dummy headform testing. In addition, post mortem human surrogate tests utilizing the worst-case unconstrained mandible condition yield 40% and 80% normalized root mean square error in angular velocity and angular acceleration respectively. These errors can be modeled using a simple spring–mass system in which the soft mouthguard material near the sensors acts as a spring and the mandible as a mass. However, the mouthguard can be designed to mitigate these disturbances by isolating sensors from mandible loads, improving accuracy to below 15% normalized root mean square error in all kinematic measures. Thus, while current mouthguards would suffer from measurement errors in the worst-case unconstrained mandible condition, future mouthguards should be designed to account for these disturbances and future validation testing should include unconstrained mandibles to ensure proper accuracy. [ABSTRACT FROM AUTHOR]

The latest findings on the ergogenic effects of a dentistry-design, bite-aligning mouthpiece require additional research to assess its impact on anaerobic ability and ventilatory parameters. This paper was aimed at determining the ergogenic acute effects of wearing a custom-made mouthpiece on oral airflow dynamics, 30-s Wingate Anaerobic Test performance parameters. Twenty-eight healthy and physically-active male subjects (age: 24.50 ± 3.32, height: 181.34 ± 7.4, weight: 78.14 ± 8.21), were voluntarily studied. The subjects were first briefed on the test protocols, and then performed the 30s Wingate test and Spirometer test. The experimental trials were performed in a random counterbalanced order. We evaluate maximum expiratory volume (VEmax L min(-1)), mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), rate to fatigue (Ws(-1)) and lactate production (mMol L(-1)), rate of perceived exertion (RPE). There were significant differences between mouthguard and no-mouthguard conditions in mean power (W kg(-1)), peak power (W kg(-1)), time to peak (s), and rate to fatigue (Ws(-1)) for the 30-s Wingate Anaerobic Test. Significantly lower lactate production (mMol L(-1)) was observed, in mouthguard condition but no significant differences were found in RPE. In airflow dynamics, the VEmax L min(-1) was significantly higher when comparing the mouthguard and the no mouthguard conditions in both forced and unforced conditions. In conclusion, wearing a customized mouthguard improves anaerobic ability and increases forced expiratory volume. This study will help practitioners improve athlete's performance in anaerobic activities where high intensity action might provoke jaw-clenching, contributing in reductions of lactate and fatigue, and improving ventilatory parameters. [ABSTRACT FROM AUTHOR]

• A physics based analytical model of laser bending is developed. • Analytical results are in good agreement with those achieved in experimental data. • The material absorption coefficient is found based on inverse approach by matching the analytical results with the experimental data. • A detailed parametric study is carried out to understand the influence of different laser bending process parameters. • Mechanical analysis of the laser scanned sheets are studied experimentally. This paper presents a physics-based analytical model to analyze the temperature field and bend angle in a material irradiated by a moving laser heat source. The solution for temperature field involves use of integral transform technique to solve the three-dimensional governing heat transfer equation with consideration of heat transfer due to conduction and convection from laser-heated region to the surrounding material. Based on the strain difference caused by the developed temperature and forces under the laser-irradiated area due to laser heating, the bend angle of the sheet is calculated. The proposed analytical model considers the influence of residual heat in the previous laser scan for predicting the bend angle in multiple scans. Al 6061-T6 aluminium alloy sheet is chosen to demonstrate the efficacy of the proposed model. The results obtained with the analytical model are validated with the experimental investigation at different process conditions. The predictions of the analytical model in terms of temperature and bend angle are in good agreement with the experimental results by obtaining inversely estimated the absorption coefficient. A three-dimensional finite element model is also developed to verify the temperature field along the sheet thickness and bend angle predicted by the analytical model. By comparison, it is observed that the analytical model has promising advantage in computational efficiency compared to FEM simulations with comparable prediction accuracy, which can also broader the application of this analytical modelling method. To extend the applicability of the proposed analytical model, the influence of different process parameters such as sheet thickness, line energy, and number of passes on the laser forming process are also studied. Apart from this, microhardness, flexural strength and microstructure of laser-irradiated sheets are studied experimentally, under different parameter combinations in order to assess the applicability of Al 6061-T6 aluminium alloy sheet. The findings of the present study demonstrate the effectiveness of the proposed analytical model as an effective tool to estimate the temperature field and bend angle in laser heating process precisely and accurately, which reduces the need for time-consuming finite element model simulations and high experimental costs. [ABSTRACT FROM AUTHOR]

• The geometrical modelling of bi-metal sheets with a functional thickness and the numerical simulation of laser forming process are carried out. • The experimental tests guarantee the accuracy of the numerical approach. • The effects of various process parameters are evaluated on the bending angle of these sheets. • A statistical equation for predicting the amount of bending angle is presented. • A detailed discussion has been presented on how to activate the temperature gradient mechanism during the process. Bi-metal sheets with a functional thickness are the heterogeneous materials in which physical/mechanical properties of the sheet change from upper layer to the bottom layer. The scope of this work is to investigate the forming of copper/aluminum bi-metal sheets with a functional thickness using laser forming process. In fact, the combined properties of a bi-metal sheet make it complicated to predict the forming behavior of these materials. For this reason, laser forming process of bi-metal sheets has been simulated using a DFLUX subroutine to define the continuous scan path of laser beam. A detailed discussion has been presented on how to activate the temperature gradient mechanism during the process. Furthermore, a set of experimental tests was also performed to examine the validity of the numerical tests. Thus, the effect of each input process parameter including laser power, scan velocity, and beam diameter has been examined. A full-factorial design of experiment has been utilized to specify the quantitative influences of the parameters on the final bending angle. A statistical model has been also derived for predicting the bending angle in laser forming of bi-metal sheets. The numerical results show that by increasing the laser power and scan velocity and decreasing the beam diameter a maximum forming magnitude would be achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flexible biomimetic SERS substrates were fabricated by nanoimprint technology. • Linear relationship in SERS detection was significantly corrected by the intrinsic Raman peak of PDMS. • The significance of manufacturing highly conformed micro/nanofabrication from the surface to be tested was pointed out. Although biomimetic surface enhanced Raman scattering (SERS) substrate which makes use of naturally existing raw materials have been fully utilized, it remains challenging to achieve credible quantitative detection. Herein, nanoimprint technology was exploited to engineer internal standard (IS) enabled quantitative flexible biomimetic SERS substrates, in which polydimethylsiloxane (PDMS) with intrinsic Raman signal was utilized as a tool to reversely duplicate surface structures from different agriculture products and then deposited with Ag nanoparticles. The resultant four kinds of biomimetic SERS substrates with different surface geometries all permit highly sensitive assay with enhancement factors (EFs) of about 106 in both drop-dry and in situ SERS detection modes. Moreover, the quantitative degree in the SERS detection was effectively corrected based on the IS strategy. Finally, an ingenious interactive in situ SERS detection was conducted. Interestingly, the maximum recovery rate was achieved when the template food was used as target surface compared with other foods, indicating the significance of manufacturing the highly conformed SERS-active structure from the surface to be tested. The proposed quantitative biomimetic SERS substrate is expected to be widely used in the field of biochemical supervision. [ABSTRACT FROM AUTHOR]

• Analysis of z -directional distribution of liquids in thin, porous media over time. • 1D NMR profiling method with high spatial and temporal resolution. • Saturated reference enables evaluation of local liquid saturation and liquid amount. • Time-dependent changes in liquid distribution and drying kinetics were observed. The through-thickness distribution of liquids and liquid migration over time in thin, porous media is highly relevant for the production and product properties of materials such as textiles, membranes, paper, barrier materials, and thin films. We present a 1D NMR profiling method for the analysis of through-thickness liquid distribution during liquid absorption, migration, and drying of thin sheets. The good temporal resolution (1.3 s) and high spatial resolution (10 μm) make it possible to study changes of liquid distribution in sheets of about 100 μm thickness. A key aspect of our method is the simultaneous scanning of a liquid saturated reference sheet. Using a reference, local liquid saturation and absolute amount of liquid present over time can be evaluated. We studied the drying of water-based inkjet ink on paper substrates with differing water absorption behaviors. Differences in z -directional liquid distribution, penetration depth, and drying kinetics over time could be observed. [ABSTRACT FROM AUTHOR]

In this study, Ti6Al4V sheet blocks with a thickness of 1 mm were joined in a single lap joint form using a two-component epoxy adhesive binder. In order to increase the bonding performance, the surfaces were prepared with sandpaper, acid etching, and laser texturing before the bonding process. Laser texturing was carried out with an average 20 W laser power with 25 kHz laser frequency and variable scanning speeds (1000, 750, 500 mm/s). The generated surfaces were examined with an optical microscope, and surface roughness values were measured. The wettability properties of the surfaces were examined by the sessile drop test method. It was observed that the laser texturing process increases surface wettability significantly. The strength of the adhesive joints was determined using a tensile test setup. Additionally, fracture surfaces were examined under a scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis was conducted. According to these results, it was observed that all surface preparation processes increased the adhesive bonding and shear lap joint bond strength. Especially, up to a 4.5 times increase was observed compared to the sample not treated with laser texturing. [ABSTRACT FROM AUTHOR]

Poor adherence to drug dosing schedule is responsible for ∼50% of hospitalization cases. Most patients fail to adhere to a strict dosing schedule due to invasive drug administration, off-target toxicities, or medical conditions like dementia. The emerging concept of wearable devices (WDs), implantable devices (IDs) and combined wearable and implantable devices (WIDs) for drug delivery has created new opportunities for treating patients with chronic diseases needing repeated and long-term medical attention like diabetes, ocular disorders, cancer, wound healing, cardiovascular diseases, and contraception. WDs, worn on the body surface have created appealing non-invasive, self-administrable drug delivery platforms which receive huge patient compliance. Microneedle-skin patches, wound healing patches, drug-eluting contact lenses, mouth guards, intra-vaginal rings, pharmaceutical jewelry, and drug-loaded self-care textiles are popular WDs explored in drug delivery. In contrast, IDs are surgically placed inside body tissue allowing higher payload and enhanced localized effect for an extended duration. Hormone micropumps, hydrogel/nanofibrous depot, coronary stents, intravitreal devices, and intrauterine devices are some representative examples of IDs. In this review, we have described the past 10 years of research progress on drug-delivering WDs and IDs in the context of treating diseases that demand repeated and long-term medication, especially those affecting soft tissues. We highlighted several technical challenges that need to be addressed before considering the translation of such technologies to clinics. [ABSTRACT FROM AUTHOR]

Improving radio frequency (RF) heating uniformity is a key to obtain a good pasteurization effect while maintaining the quality of food product. The objective of this study was for providing a new method to improve the RF heating uniformity by adding aluminum foil sheets around the container walls. A 27.12 MHz, 6 kW pilot-scale RF system at an electrode gap of 110 mm was used to evaluate the heating rate and temperature distribution of wheat kernels in a rectangular container with the location, size and thickness of the foil sheet. The results showed that the RF heating behavior was influenced by foil sheets added at different oriented walls of the container. A cold spot area appeared in the place closed to the foil sheet wall at the vertically oriented addition, while a cold spot in the center and hot spots in the corners and edges still existed with the horizontally oriented addition of the sheet. The presence of foil sheet had an influence on the voltage, power input and energy efficiency. Effect of different foil sheet wall on heating behavior of samples was related to the reflection of foil sheet to RF electromagnetic wave. The heating uniformity index (λ) value decreased when the foil sheet was placed at the container bottom wall, and with increasing foil sheet size and thickness. A clearly improved RF heating uniformity can be obtained by increasing foil sheet size and thickness at the container bottom wall. • Adding aluminum foil sheets on container walls may improve RF heating uniformity. • Effects of location, size and thickness of foil sheets were evaluated on RF heating behavior. • Heating uniformity index decreased with increasing foil sheet size and thickness. • Providing better RF heating uniformity is helpful to develop effective pasteurizing technology. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Several mechanisms have been purported to describe how mouthguards protect the orofacial complex against injury. As the properties needed for these mechanisms to be effective are temperature and frequency dependent, the specific aim of this study was to provide a comprehensive thermal characterization of commercial mouthguard materials. Methods: Five commercially representative thermoplastic mouthguard materials (Essix™ Resin, Erkoflex™, Proform™-regular, Proform™-laminate, and Polyshok™) were tested. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques were implemented to measure thermal transitions and mechanical properties. Measurements were conducted three times per sample. One-way ANOVA and one-sample t-tests were used to test for differences between commercial products on selected mean thermal property values. Results: The DSC measurements indicated no differences between commercial materials for mean glass transition (p =0.053), onset melt (p =0.973), or peak melt (p =0.436) temperatures. Likewise, DMA measurements revealed no differences between commercial materials for the mean glass transition (p =0.093), storage modulus (p =0.257), or loss modulus (p =0.172) properties, respectively. The one-sample t-tests revealed that glass transition temperatures were different from intra-oral temperature (p <0.005) for all materials. Significance: Commercialized mouthguard materials are sensitive to repetitive heating and cooling cycles, prolonged thermal treatment, and have glass transitions well below their end-use intra-oral temperature. As such, these materials are functioning as elastomers and not optimal mechanical damping materials. Dental clinicians, healthcare practitioners, or end-users should be aware that these materials are at best problematic with respect to this protective mechanism. [Copyright &y& Elsevier]

Abstract: Objectives: Contemporary mouthguard materials need to perform consistently over a wide range of possible temperatures (−20 to 40°C). Therefore the specific aim of this study was to characterize commercialized mouthguard materials’ properties and investigate the effect of temperature on these properties. Methods: Five commercially representative thermoplastic mouthguard materials (Essix™ Resin, Erkoflex™, Proform™-regular, Proform™-laminate, and Polyshok™) were tested. The durometer hardness, water absorption, tear strength, and impact attenuation of the mouthguard materials were measured according to ASTM D2240-05, D570-98 (2005), D624-00, and ASTM D6110-06f (modified) guidelines. Tests were conducted on five separate specimens at both room 23±2°C and intra-oral 37±2°C temperatures. Independent t-tests (α =0.05) were used to test for differences between room and intra-oral temperatures. Results: Material hardness decreased (p <0.05) from room to intra-oral temperatures for all mouthguard materials. Water absorption increased (p <0.05) from room to intra-oral temperatures for all mouthguard materials. Tear strength decreased (p <0.05) from room to intra-oral temperatures for all mouthguard materials. Impact attenuation between room and intra-oral temperatures was different (p <0.05) for the Erkoflex™, Proform™-laminate, and Polyshok™ material respectfully. However, there was no difference between temperatures for the Essix™ Resin (p =.058) or Proform™-regular (p =.275) materials. Significance: Temperature measureably affects the physical and mechanical properties of mouthguard materials. It is particularly noteworthy that none of the commercialized products met current ANSI and SAI standards for impact attenuation. [Copyright &y& Elsevier]

• Novel criteria were established to identify the zones of kerf profile deviation. • Optimized parameters for kerf profile deviation of PMMA sheets cut by CO 2 laser were achieved. • Focal point position followed by cutting speed and laser power are the most significant process parameters. • A neural network-based model was used to predict the different zones of kerf profile deviation. One crucial issue in laser beam cutting is the proper selection of processing factors to achieve straight kerfs. In this study, the influence of cutting speed, laser power, gas pressure, and focal point position on the CO 2 laser cutting of polymethylmethacrylate (PMMA) sheets of different thicknesses is analyzed to select optimal operational parameters. A design of experiment (DOE) of response surface type was then carried out to identify the influence of each factor and set the optimal ranges of the process parameters to achieve flat kerfs without streaks or surface imperfections. A laser with power values ranging from 3000 to 4200 W was used as an energy source. The interest intervals for the rest of the process parameters were justified by the literature consulted. Three new criteria were established to estimate a kerf profile deviation (KPD) response considering all the kerf area cut by the laser, defining these criteria as the difference between the resulting kerf profile and a straight kerf. As final results, the kerf profile deviation response was improved by 22.6%, 42.4%, 15.6%, and 22.1% in PMMA having thicknesses of 4, 8, 12, and 20 mm, respectively. Finally, an artificial neural network (ANN)-based model is used to predict the value of KPD, taking into account all the variables involved in the cutting process and the different criteria applied to classify the stage of profile deviation. The contributions of this paper are, in the first place, the proposal of new metrics to evaluate the kerf profile in PMMA sheets. Secondly, establishing optimal cutting parameters and ANN as an accurate method in geometrical modeling and relating the influential variables on the laser cutting process. [ABSTRACT FROM AUTHOR]