bluuebunny/crossref_metadata_2025 huggingface dataset:
Gestational glycosuria, proteinuria, and borderline hypertension in pregnancy are predictors for the later onset of maternal chronic disease
Authors: Hosoya Satoshi , Ogawa Kohei , Morisaki Naho , Okamoto Aikou , Arata Naoko , Sago Haruhiko
Published: November 2022

Aim

Although hypertensive disorders of pregnancy and gestational diabetes mellitus (DM) are risk factors for hypertension, DM, and kidney disease in later life, the association of gestational glycosuria, proteinuria, and borderline hypertension with these chronic diseases has been unclear.

Methods

This cross‐sectional study was conducted between April 2017 and November 2020 at a Japanese tertiary hospital. Three variables listed in the Maternal and Child Health Handbook were analyzed: glycosuria, proteinuria, and systolic blood pressure (<130, 130–139, and ≥ 140 mmHg) during pregnancy. The incidences of DM, kidney disease, and hypertension self‐reported by mothers of pregnant women on a questionnaire were assessed with logistic regression analysis.

Results

The 312 women completed the questionnaires an average of 35.8 ± 4.2 years after delivering their daughters. Risk for DM was significantly increased among women with glycosuria (adjusted odds ratio [aOR], 3.62; 95% confidence interval [CI], 1.21–10.9), and risk for kidney disease was significantly increased among women with proteinuria (aOR, 4.07; 95% CI, 1.29–12.9). Risk for hypertension was significant in women whose blood pressures were ≥ 140 mmHg (aOR, 4.26; 95% CI, 1.96–9.24), but the association between blood pressures of 130–139 mmHg and hypertension was not significant (aOR, 1.72; 95% CI, 0.95–3.11); however, a significant positive trend (p < 0.001) between increasing blood pressure and hypertension was observed.

Conclusions

Gestational glycosuria, proteinuria, and increased blood pressure were associated with the development of maternal chronic diseases. These standard and inexpensive assessments may improve lifelong health management in women.
Do dental parameters predict severity of obstructive sleep apnea and mandibular advancement device therapy outcomes? A pilot study
Authors: Uniken Venema Julia Anne Margarethe , Bosschieter Pien Fenneke Nicole , Hoekema Aarnoud , Plooij Joanneke Marielle , Lobbezoo Frank , de Vries Nico
Published: November 2022

Background

Mandibular Advancement Devices (MAD's) are oral appliances commonly used in treatment of Obstructive Sleep Apnea (OSA). OSA severity and certain other factors, such as BMI and neck circumference, correlate with MAD therapy success. So far, the predictive value of dental parameters, such as dental profile, molar‐classification, overjet, overbite, maximal retrusion, maximal protrusion and protrusive range, has not been fully investigated.

Objectives

We aimed to investigate whether dental parameters influence OSA severity and MAD therapy outcome and could therefore be helpful in phenotyping OSA patients. Furthermore, we studied the predictive power of dental parameters for OSA severity and successful MAD therapy. We hypothesise that specific dental parameters correlate with more severe OSA and with more successful MAD treatment.

Methods

We performed a cohort study, including OSA patients diagnosed by polysomnography (PSG). Dental parameters were collected. Objective treatment outcome was collected by performing a PSG with MAD after three months of therapy. Differences between OSA severity groups and MAD treatment outcomes were analysed and dental parameters were correlated between groups.

Results

The relation between dental parameters and OSA severity was analysed in 143 patients, fifty patients had a PSG with MAD in situ after a 3‐month therapy. The median baseline Apnea Hypopnea Index (AHI) significantly reduced from 17.6 (8.7–29.3) to 11.1 (5.5–17.5). Overbite and maximal retrusion differed significantly between mild, moderate and severe OSA. Other dental parameters did not differ significantly between the groups, nor correlated with OSA severity or MAD treatment outcome.

Conclusion

In this study, no correlation between dental parameters and OSA severity or MAD treatment outcomes was found. Therefore, screening patients for OSA and MAD treatment outcome based on dental parameters is currently not possible.
TOMM34 promotes cell proliferation, migration, and invasion of OSCC and modulates mitochondrial function
Authors: Huang Yunyi , Chen Zhipei , Chen Xuanyi , Chen Xiaohua , Xu Meng
Published: November 2022

Background

34‐kDa translocase of the outer mitochondrial membrane (TOMM34) has been reported highly expressed in many cancers and is positively correlated to poorer prognosis. Our prior study showed TOMM34 is highly expressed in oral squamous cell carcinoma (OSCC) and is closely related to TNM classification and tumor size. TOMM34 is also associated with lymph node metastasis and poorer overall survival and disease‐free survival in HPV‐negative OSCC.

Methods

We knocked down TOMM34 in OSCC cells (SCC15, HPV positive; Cal27, HPV negative) with siRNA and over‐expressed with plasmids. The effects of TOMM34 on cell proliferation, migration and invasion abilities were detected by EdU assay, CCK‐8 assay, wound‐healing assay, and Transwell assay. We also detected the mitochondrial morphology and the intracellular Reactive Oxygen Species (ROS) level by fluorescence staining and flow cytometry. Finally, we monitored the protein levels of ERK pathway‐related molecules.

Results

TOMM34 knockdown decreased the proliferation in SCC15 and Cal27, and weakened the migration and invasion abilities as well. Mitochondria became shorter, in the shape of dots or short rods, suggesting that mitochondrial damage occurred. Intracellular ROS levels increased significantly after knockdown TOMM34 and decreased after over‐expressing TOMM34. The phosphorylation levels of ERK1/2 and MEK1/2 in SCC15 were significantly higher than in Cal27. Besides, the phosphorylation levels of ERK1/2 and MEK1/2 were inhibited in SCC15 after knockdown of TOMM34, but not in Cal27.

Conclusion

TOMM34 promotes the cell proliferation, migration, and invasion of OSCC. In addition, TOMM34 participates in maintaining the mitochondrial shape and reducing the intracellular ROS level to protect cancer cells. Furthermore, TOMM34 increases the activity of ERK1/2 and MEK1/2 in HPV‐positive OSCC cells but not in HPV‐negative.
Effects of the density of extruded pellets on starch digestion kinetics, rumen fermentation, fiber digestibility and enteric methane production in dairy cows
Authors: Khan Ghulam Q. , Prestløkken Egil , Lund Peter , Hellwing Anne L. F. , Larsen Mogens
Published: November 2022

Dynamics of starch digestion in dairy cows fed extruded pellets differing in physical functional properties were investigated by measuring starch digestibility, post‐prandial rumen fermentation patterns, and post‐prandial duodenal starch appearance. Additionally, starch digestion effects on neutral detergent fiber (NDF) digestibility and methane (CH4) emission were studied. Pure barley was extruded to produce three treatments having pellets of either low‐density (LD), medium‐density (MD) or high‐density (HD). The experiment was conducted in a 3 × 3 Latin square design using three lactating Danish Holstein cows fitted with ruminal, duodenal and ileal cannulas. After the allocation of experimental concentrate directly into the rumen through the rumen cannula, cows were fed a basal diet low in starch. Eight samples were collected on equal time intervals (9 h) from duodenal digesta, ileal digesta and feces (grab sample) to determine digestibility. For post‐prandial rumen fermentation patterns, four sample sets of rumen dorsal, medial and ventral fluid were taken from each cow, whereas for post‐prandial duodenal starch appearance, 14 samples of duodenal chyme were obtained from each cow relative to morning feeding of experimental concentrate at 07:00 h. Ruminal, small intestinal, hindgut and total tract digestibility of starch did not differ among treatments. Similarly, NDF digestibility and CH4 emission also remained unaffected by treatments. However, compared with the LD and MD treatments, the HD treatment showed higher acetate: propionate ratio at all positions in the rumen and a higher post‐prandial duodenal starch appearance. This indicates lower ruminal starch degradation (RSD) and higher starch flow into the small intestine for HD treatment. In conclusion, the current study indicates that pellets' physical properties can manipulate RSD, where pellets with high density and fluid stability can partly shift starch digestion from the rumen to the small intestine. Indeed, further investigations are needed.
Hyperammonaemia disrupts daily rhythms reversibly by elevating glutamate in the central circadian pacemaker
Authors: Granados‐Fuentes Daniel , Cho Kevin , Patti Gary J. , Costa Rodolfo , Herzog Erik D. , Montagnese Sara
Published: November 2022

Patients with cirrhosis exhibit features of circadian disruption. Hyperammonaemia has been suggested to impair both homeostatic and circadian sleep regulation. Here, we tested if hyperammonaemia directly disrupts circadian rhythm generation in the central pacemaker, the suprachiasmatic nuclei (SCN) of the hypothalamus. Wheel‐running activity was recorded from mice fed with a hyperammonaemic or normal diet for ~35 days in a 12:12 light–dark (LD) cycle followed by ~15 days in constant darkness (DD). The expression of the clock protein PERIOD2 (PER2) was recorded from SCN explants before, during and after ammonia exposure, ±glutamate receptor antagonists. In LD, hyperammonaemic mice advanced their daily activity onset time by ~1 h (16.8 ± 0.3 vs. 18.1 ± 0.04 h, p = .009) and decreased their total activity, concentrating it during the first half of the night. In DD, hyperammonaemia reduced the amplitude of daily activity (551.5 ± 27.7 vs. 724.9 ± 59 counts, p = .007), with no changes in circadian period. Ammonia (≥0.01 mM) rapidly and significantly reduced PER2 amplitude, and slightly increased circadian period. The decrease in PER2 amplitude correlated with decreased synchrony among circadian cells in the SCN and increased extracellular glutamate, which was rescued by AMPA glutamate receptor antagonists. These data suggest that hyperammonaemia affects circadian regulation of rest‐activity behaviour by increasing extracellular glutamate in the SCN.
The impact of xylem geometry on olive cultivar resistance to Xylella fastidiosa: An image‐based study
Authors: Walker Nancy C. , White Steven M. , McKay Fletcher Dan , Ruiz Siul A. , Rankin Kathryn E. , De Stradis Angelo , Saponari Maria , Williams Katherine A. , Petroselli Chiara , Roose Tiina
Published: November 2022

Xylella fastidiosa is a xylem‐limited plant pathogen infecting many crops globally and is the cause of the recent olive disease epidemic in Italy. One strategy proposed to mitigate losses is to replant susceptible crops with resistant varieties. Several genetic, biochemical and biophysical traits are associated to X. fastidiosa disease resistance. However, mechanisms underpinning resistance are poorly understood. We hypothesize that the susceptibility of olive cultivars to infection will correlate to xylem vessel diameters, with narrower vessels being resistant to air embolisms and having slower flow rates limiting pathogen spread. To test this, we scanned stems from four olive cultivars of varying susceptibility to X. fastidiosa using X‐ray computed tomography. Scans were processed by a bespoke methodology that segmented vessels, facilitating diameter measurements. Though significant differences were not found comparing stem‐average vessel section diameters among cultivars, they were found when comparing diameter distributions. Moreover, the measurements indicated that although vessel diameter distributions may play a role regarding the resistance of Leccino, it is unlikely they do for FS17. Considering Young–Laplace and Hagen–Poiseuille equations, we inferred differences in embolism susceptibility and hydraulic conductivity of the vasculature. Our results suggest susceptible cultivars, having a greater proportion of larger vessels, are more vulnerable to air embolisms. In addition, results suggest that under certain pressure conditions, functional vasculature in susceptible cultivars could be subject to greater stresses than in resistant cultivars. These results support investigation into xylem morphological screening to help inform olive replanting. Furthermore, our framework could test the relevance of xylem geometry to disease resistance in other crops.
Utilizing deep learning for dermal matrix quality assessment on in vivo line‐field confocal optical coherence tomography images
Authors: Breugnot Josselin , Rouaud‐Tinguely Pauline , Gilardeau Sophie , Rondeau Delphine , Bordes Sylvie , Aymard Elodie , Closs Brigitte
Published: November 2022

Background

Line‐field confocal optical coherence tomography (LC‐OCT) is an imaging technique providing non‐invasive “optical biopsies” with an isotropic spatial resolution of ∼1  μm and deep penetration until the dermis. Analysis of obtained images is classically performed by experts, thus requiring long and fastidious training and giving operator‐dependent results. In this study, the objective was to develop a new automated method to score the quality of the dermal matrix precisely, quickly, and directly from in vivo LC‐OCT images. Once validated, this new automated method was applied to assess photo‐aging‐related changes in the quality of the dermal matrix.

Materials and methods

LC‐OCT measurements were conducted on the face of 57 healthy Caucasian volunteers. The quality of the dermal matrix was scored by experts trained to evaluate the fibers’ state according to four grades. In parallel, these images were used to develop the deep learning model by adapting a MobileNetv3‐Small architecture. Once validated, this model was applied to the study of dermal matrix changes on a panel of 36 healthy Caucasian females, divided into three groups according to their age and photo‐exposition.

Results

The deep learning model was trained and tested on a set of 15 993 images. Calculated on the test data set, the accuracy score was 0.83. As expected, when applied to different volunteer groups, the model shows greater and deeper alteration of the dermal matrix for old and photoexposed subjects.

Conclusions

In conclusion, we have developed a new method that automatically scores the quality of the dermal matrix on in vivo LC‐OCT images. This accurate model could be used for further investigations, both in the dermatological and cosmetic fields.
Blood shifts between body compartments during submaximal exercise with induced expiratory flow limitation in healthy humans
Authors: Stucky Frédéric , Uva Barbara , Kayser Bengt , Aliverti Andrea
Published: November 2022

External expiratory flow limitation (EFLe) can be applied in healthy subjects to mimic the effects of chronic obstructive pulmonary disease during exercise. At maximal exercise intensity, EFLe leads to exercise intolerance owing to respiratory pump dysfunction limiting venous return. We quantified blood shifts between body compartments to determine whether such effects can be observed during submaximal exercise, when the load on the respiratory system is milder. Ten healthy men (25.2 ± 3.2 years of age, 177.3 ± 5.4 cm in height and weighing 67.4 ± 5.8 kg) exercised at 100 W (∼40% of maximal oxygen uptake) while breathing spontaneously (CTRL) or with EFLe. We measured respiratory dynamics with optoelectronic plethysmography, oesophageal (Pes) and gastric (Pga) pressures with balloon catheters, and blood shifting between body compartments with double body plethysmography. During exercise, EFLe resulted in the following changes: (i) greater intrabreath blood shifts between the trunk and the extremities [518 ± 221 (EFLe) vs. 224 ± 60 ml (CTRL); P < 0.001] associated with lower Pes during inspiration (r = 0.53, P < 0.001) and higher Pga during expiration (r = 0.29, P < 0.024); and (ii) a progressive pooling of blood in the trunk over time (∼700 ml after 3 min of exercise; P < 0.05), explained by a predominant effect of lower inspiratory Pes (r = 0.54, P < 0.001) over that of increased Pga. It follows that during submaximal exercise, EFLe amplifies the respiratory pump mechanism, with a prevailing contribution from lower inspiratory Pes over increased expiratory Pga, drawing blood into the trunk. Whether these results can be replicated in chronic obstructive pulmonary disease patients remains to be determined.

image

Key points

External expiratory flow limitation (EFLe) can be applied in healthy subjects to mimic the effects of chronic obstructive pulmonary disease and safely study the mechanisms of exercise intolerance associated with the disease.

At maximal exercise intensity with EFLe, exercise intolerance results from high expiratory pressures altering the respiratory pump mechanism and limiting venous return.

We used double body plethysmography to quantify blood shifting between the trunk and the extremities and to examine whether the same effects occur with EFLe at submaximal exercise intensity, where the increase in expiratory pressures is milder.

Our data show that during submaximal exercise, EFLe amplifies the respiratory pump mechanism, each breath producing greater blood displacements between the trunk and the extremities, with a prevailing effect from lower inspiratory intrathoracic pressure progressively drawing blood into the trunk.

These results help us to understand the haemodynamic effects of respiratory pressures during submaximal exercise with expiratory flow restriction.
Numerical Study of Radiation and Fuel–Air Unmixedness on the Performance of a Dry Low NOx Combustor
Authors: Wiranegara Raditya Yudha , Igie Uyioghosa , Ghali Pierre , Zhao Rang , Abbott David , Hamilton Richard
Published: November 2022

The development of gas turbine combustors is expected to consider the effects of radiation heat transfer in modeling. However, this is not always the case in many studies that neglect this for adiabatic conditions. The effect of radiation is substantiated here, concerning the impact on the performance, mainly the emissions. Also, the fuel–air unmixedness (mixing quality) influenced by the combustor design and operational settings has been investigated with regard to the emissions. The work was conducted with a Mitsubishi-type dry low NOx combustor developed and validated against experimental data. This 3D computational fluid dynamics study was implemented using Reynolds-averaged Navier Stokes simulation and the radiative transfer equation model. It shows that NO, CO, and combustor outlet temperature reduce when the radiative effect is considered. The reductions are 17.6% and below 1% for the others, respectively. Thus, indicating a significant effect on NO. For unmixedness across the combustor in a non-reacting simulation, the mixing quality shows a direct relationship with the turbulence kinetic energy (TKE) in the reacting case. The most significant improvements in unmixedness are shown around the main burner. Also, the baseload shows better mixing, higher TKE, and lower emissions (particularly NO) at the combustor outlet, compared to part-load.
Synthesis of Recursive Control Barrier Functions
Authors: de Castro Ricardo , Feng Shuang
Published: November 2022

This paper deals with the enforcement of safety constraints using control barrier functions (CBFs). We focus on dynamic systems that have high relative degree and where the output needs to be differentiated multiple times to obtain an explicit dependence on the control input. As the system approaches operating points that are close to the safety boundary, the CBF shrinks the allowed control action space. To quantify this shrinkage, we propose practical proxy metrics to capture the volume of the CBFs action space. We exploit these proxy metrics to derive sum-of-squares optimization formulations that synthesize CBFs with high-order degree, in particular their extended class K functions. We apply this tuning technique to synthesize CBFs that avoid vehicle collisions in an adaptive cruise control problem. Simulation results demonstrate the ability of our tuning approach to reduce loss of control performance when the system operates close to the safety boundary.
Research on the Mechanism of Cathode Failure of Lead-Acid Battery Under Extreme Conditions
Authors: Li Yaowei , Lyu Nawei , Jin Yang
Published: November 2022

Lead-acid batteries have the advantages of wide temperature adaptability, large discharge power, and high safety factor. It is still widely used in electrochemical energy storage systems. In order to ensure the application of batteries under extreme working conditions, it is necessary to explore the degradation mechanism. In this study, the experimental battery is the same type of 2 V-500 Ah lead-acid battery produced by different manufacturers. First, the three batteries were subjected to the same high temperature and high current cycle thermal shock test (50 °C, 0.2 C current) combined with quantitative analysis of plate active material and microscopic morphology observation. In addition, numerical studies are used to simulate the distribution of electrical parameters on the positive plate and grid. The above three parts are combined to study the causes of accelerated battery decay under high temperature and high current conditions. The results showed that the extreme conditions aggravated the non-uniformity of the potential distribution of the positive plate and the grid, which increased by 10.62% and 51.59%, respectively. The battery with higher remaining capacity has more α-PbO2 in the active material, and has a considerable amount of β-PbO2. The battery with the smallest remaining capacity has the largest volume of active material. The volume of the material affects the electrochemical reaction surface area. The larger the volume of the material, the higher the resistance of that part, which will lead to an increase in the overall impedance of the battery.
Influence Mechanism of Trimming Impeller Diameter in a Centrifugal Pump by Computational Fluid Dynamics Investigation
Authors: Han Yong , Li Hui , Tiganik Taavi , Wang Yuqiang , Zhou Ling
Published: November 2022

Trimming the impeller diameter of a centrifugal pump is the easiest and most economical way to adjust its efficient operating range based on its original performance. Three impellers obtained by trimming the diameter are investigated. Energy performance, internal flow field, and entropy production analysis have been discussed in different cases. The results show that trimming the impeller diameter causes a great change in the energy performance of centrifugal pumps. The turbulent kinetic energy (TKE) distribution and entropy production also change significantly. The best efficiency point (BEP) shifts to low flowrate with trimming impeller diameter. The BEP shift rate was 6.67% and 20% for trimming amounts of 5.15% and 10.29%, respectively. As the impeller diameter decreases, the backflow phenomenon that occurs at the diffuser inlet at low flowrate improves. The ratio of mechanical energy to kinetic energy and pressure energy is not constant for pumps with different impeller diameters. The energy performance changes are mainly caused by flow changes inside the impeller, chamber, and diffuser. The results could be referred to as the design and selection of centrifugal pumps.
Effect of Wrapping Force on the Effective Elastic Behavior of Packed Cylinders
Authors: Yin Huiming , Cui Junhe , Teka Linda G. , Zadshir Mehdi
Published: November 2022

When cylinders are packed and wrapped by the bands around the surface, the effective elastic behavior in the cross section of the assembly, which is of significance to its stability and integrity, can be controlled by the wrapping force in the band. The wrapping force is transferred to the cylinders through the Hertz contact between each pair of neighboring cylinders, which is validated by the experiments. The Singum model is introduced to study the mechanical behaviors of the packed cylinders with two-dimensional (2D) packing lattices, in which an inner cylinder is simulated by a continuum particle of Singum and the inter-cylinder force is governed by the Hertz contact model so as to derive the effective stress-strain relationship. The wrapping force will produce configurational forces given a displacement variation, which significantly changes the effective stiffness of the packed cylinders. The hexagonal packing exhibits isotropic elasticity whereas the square packing is anisotropic. The efficacy of our model is demonstrated by comparing the closed form elasticity against the numerical simulation and the previous models. The explicit form of elasticity can be used for packing design and quality control of cable construction and installation.
Onset of Flow Separation Phenomenon in a Low-Specific Speed Centrifugal Pump Impeller
Authors: Liu Xiao-Dong , Farhat Mohamed , Li Yao-Jun , Liu Zhu-Qing , Yang Wei
Published: November 2022

The efficiency of centrifugal pumps drops sharply when the flowrate is reduced below a threshold value. This is due to a profound change in the flow structure, characterized by a large of portion flow separation near the impeller blades and the formation of energy-intensive recirculation zones. So far, it is not clear how such flow separation may initiate and develop. This study combines state-of-the-art experiments and numerical simulations to explore the onset of flow separation in centrifugal impellers. In particular, a high-frequency particle image velocimetry (PIV) system is used to visualize the velocity field in impeller channels. The continuous relative velocity value and deviation angle relative to the blade surface are displayed before the stall inception conditions. Meanwhile, the validated numerical simulation method is used to compute the flow at similar experimental conditions. The results clearly show a cylindrical vortex band exists near the impeller shroud. As the flowrate decreases, the vortex grows gradually stronger, while moving to the junction between the impeller shroud and blade suction side, and then toward impeller hub along the blade suction side. This growing and moving vortex is the main cause of the flow separation near blade suction side observed in our experiments. Interestingly, the impeller head remains insensitive to this vortex until it causes the flowrate in the adjacent impeller channels to be redistributed. This led us to believe that stalled flow can be detected before it affects the hydrodynamic performances.
Metric-Based Meta-Learning for Cross-Domain Few-Shot Identification of Welding Defect
Authors: Xie Tingli , Huang Xufeng , Choi Seung-Kyum
Published: November 2022

With the development of deep learning and information technologies, intelligent welding systems have been further developed, which achieve satisfactory identification of defective welds. However, the lack of labeled samples and complex working conditions can hinder the improvement of identification models. This paper explores a novel method based on metric-based meta-learning for the classification of welding defects with cross-domain few-shot (CDFS) problems. First, an embedding module using convolutional neural network (CNN) is applied to perform feature extraction and generate prototypes. The embedding module only contains one input layer, multiple convolutions, max-pooling operators, and batch normalization layers, which has the advantages of low computational cost and high generalization of images. Then the prototypical module using a prototypical network (PN) is proposed to reduce the influence of domain-shift caused by different materials or measurements using the representations in embedding space, which can improve the performance of few-shot welding defects identification. The proposed approach is verified on real welding defects under different welding conditions from the Camera-Welds dataset. For the K-shot classification on different tasks, the proposed method achieves the highest average testing accuracy compared to the existing methods. The results show the proposed method outperforms the model-based meta-learning (MAML) and transfer-learning method.
Systematic Generation of 5-Axis Manufacturing Machines
Authors: Jetton Cole , Rudd Liam , Campbell Matthew I.
Published: November 2022

Additive and subtractive machines that exhibit five and six degrees of freedom are on the cutting edge of manufacturing technology. The workspace for these machines can be determined by the joint types and orientations chosen during the design process. Thus, many joint configurations should be considered during the design. This paper presents a method for exhaustively generating and evaluating serial mechanisms using computer algebra systems and investigates four machines as case studies. The position and angle of the end point of the mechanism was computed as a function of joint actuation allowing a configuration to be evaluated in a variety of metrics including volume, tool angle range, and singularities (where the machine loses a degree of freedom). The exhaustive search generated and tested joint configurations to determine which had five axis control within their workspace. The case studies looked at four machines in detail, using both convex hull and alpha shape to calculate the workspace volume, their ability to maintain five axis control, and compared the viability of each configuration. The application of this method led to several different, but viable configurations. One can then narrow down further based on situational requirements of the target environment.
Maneuvering Control of a Planar Snake Robot Locomotion Using a Combined Heading-Velocity-Shape Strategy
Authors: Haghshenas-Jaryani Mahdi
Published: November 2022

This paper presents a combined shape-velocity-heading control for planar snake robots to navigate confined environments using the lateral undulatory locomotion. The kinematics and dynamics of shape-changing were studied to find the connection between the gait parameters of the Serpenoid curve and the width of the robot locomotion while following the desired trajectories. The phase shift in between joint angles was identified as the parameter of interest for controlling the width of snake robots. The controller includes an outer-loop to adjust the parameters of the lateral undulation gait to achieve the desired shape, linear velocity, and heading direction in the Cartesian space while the inner-loop determines the torques at each joint of the snake robot to follow the desired joint trajectories. The control algorithm was tested on a planar 6-link snake robot model and was examined in different simulation cases of adjusting the robot’s shape to the desired width while maintaining the desired heading direction and linear velocity. The simulation results have shown the feasibility and effectiveness of the combined heading, velocity, and shape control algorithm in the navigation of a 6-link snake robot in simple and complex simulated multichannel cluttered environments.
Direct 4D Printing of a Deployable Polymer Wave Spring
Authors: Chapuis Joël N. , Widmer Andrin M. , Shea Kristina
Published: November 2022

4D printing is now commonly defined as a targeted evolution of a 3D printed structure to change its shape, properties, and functionality over time. In direct 4D printing this targeted evolution is embedded in the structure during the 3D printing process. A heat stimulus can be used to trigger a transition between two states of a printed shape memory polymer. 3D and 4D printing have greatly expanded the design space of a variety of engineering parts. However, 3D printed parts often show anisotropic behavior due to layering, especially when using fused filament fabrication. Here, it is shown how direct 4D printing on a fused filament fabrication system can be used to create deployable polymer wave springs. By introducing a pattern of multimaterial bilayer actuators into the wave spring, it can be printed flat and deployed to a designed spring shape through a thermal stimulus. This method eliminates the typical layering issues found in 3D printed springs due to printing at angles. Additionally, it reduces the print time and support material consumption. These findings show the great potential of direct 4D printing on 3D printers using fused filament fabrication to create functional, 4D printed components with complex geometry, such as polymer springs.
Analytical Lumped-Parameter Model of Misaligned Gear Contacts for Efficient System Level Drivetrain Simulations
Authors: Marco I Jordan Jordi , Blockmans Bart , Desmet Wim
Published: November 2022

Reliable system-level simulation tools capable of modelling and predicting the physical interactions between components are of special interest in the analysis of mecha(tro)nic drivetrains. In such drivetrains the flexibilities of shafts and bearings alter the gear alignment conditions, thereby requiring gear contact models that are capable of capturing the associated misalignment effects. In this contribution, an efficient yet accurate model for misaligned helical gear contact analysis is derived by lumping a distributed-parameter model that was recently developed by the authors and validated numerically by comparison with finite element simulations. The transformation into a lumped-parameter model relies on a computationally efficient linearization approach that can be generalized to other gear contact models. The developed model is numerically validated on the component-level by comparison with finite element simulations of a helical gear pair considering various misalignments. The twisting rotation is shown to be the most influential misalignment, significantly altering the transmission error and thereby dynamic performance of the gear pair, and is well-captured by the developed lumped-parameter model. In order to demonstrate the model’s capabilities and computational efficiency in a system-level simulation, the model is implemented in a port-based multi-physical simulation environment, where it is used to simulate a two-stage helical automotive transaxle.
Investigation of Mechanical Engineering Students’ Perceptions of Design Process Models
Authors: Dugan Kelley E. , Daly Shanna R.
Published: November 2022

Engineering designers, who are increasingly tasked with solving complex problems, leverage various forms of support to practice and develop their design skills as well as ultimately navigate the complexity of the problems with which they are faced. Design process models are one such form of support, particularly those process models that prescribe how to design. To better understand how process models impact design approaches, this preliminary study analyzed semi-structured interviews — focused on participants’ perceptions of three design process models — with six upper-level mechanical engineering students. Across participants’ responses, we identified eight dimensions used to distinguish the usefulness of each process model: impacts considered, project scope, stakeholder interactions, problem definition, project deliverable, solution novelty, solution type, and process applicability. In addition, participants differentiated the three process models based on iteration and the level of detail within a model. Our findings highlight the importance of accounting for varying interpretations across process model users and suggest that students would benefit from multiple design process models, including process models that recognize society and people in engineering decision-making.
Higher-Order Kinematics of Lower-Pair Chains With Hyper-Multidual Algebra
Authors: Condurache Daniel
Published: November 2022

This paper proposes a new computational method based on vector and tensor calculus and the properties of dual and multidual algebra for higher-order acceleration field in the case of rigid body motion. A closed-form coordinate-free solution is presented, this result being generated by the morphism between the Lie group of the rigid body displacements and the Lie group of the orthogonal hyper-multidual tensors. The solution is put into practice for higher-order kinematics analysis of lower-pair serial chains. Specific cases are chosen to evaluate the properties for velocity, acceleration, jerk, and jounce.
Challenges in Implementing Digital Twins – a Survey
Authors: Trauer Jakob , Mutschler Michael , Mörtl Markus , Zimmermann Markus
Published: November 2022

Despite the undisputed potentials of Digital Twins, they are still lacking application in industry. However, the reasons for this observation are still unclear. Therefore, a survey with 61 industrial professionals was conducted to investigate the most crucial impediments in implementing Digital Twins. The research was guided by four research questions — (1) Is there still ambiguity in the terminology of Digital Twins? (2) What are characteristics of Digital Twin projects in industry? (3) What are the most crucial (categories of) impediments in implementing Digital Twins? and (4) Are non-technical issues more likely to cause problems, than technical issues? First, contextual aspects were collected. They include the background of the participant, the operating fields and size of the company, as well as characteristic information on digitalization projects in general and Digital Twin projects more specifically. Then participants were asked to rate categories of issues as well as very specific impediments with respect to their likelihood to cause problems in the implementation of Digital Twins. The results show that technical issues, like missing standardization of data and models, are still present. However, according to the collected data, non-technical issues, like a lack of expertise and specialists, are more likely to cause difficulties. Based on these results, directions for future development of Digital Twin research, like the need for a business modelling approach for Digital Twins or a teaching concept, are derived.
Knowledge and Data-Based Design and Dimensioning of Mechanical Joining Connections
Authors: Zirngibl Christoph , Sauer Christopher , Schleich Benjamin , Wartzack Sandro
Published: November 2022

Challenges in the development of resource-efficient lightweight designs, such as emission and cost targets in production, lead to an increasing demand for environmentally friendly and fast joining processes. Therefore, cold-forming mechanical joining techniques provide an energy-efficient alternative in comparison to established processes, such as spot welding. However, to ensure a sufficient reliability of the product design, not only the selection of an appropriate manufacturing and joining method, but also the suitable dimensioning and validation of the entire joining process is a crucial step. In this context, thermal processes offer a large number of design principles while mechanical joining methods mainly require extensive experimental tests and the inclusion of expert knowledge. Although few contributions already investigated the data-based analysis of mechanical joints, a system for the requirement- and manufacturing-oriented dimensioning of joining components, such as different profiles and blanks, in combination with the estimation of joint properties is not available yet. Motivated by this lack, this contribution introduces an engineering workbench for the support of design engineers in the early development phases of the knowledge and data-based design of mechanical joining connections using clinching as an example. In this regard, the approach is demonstrated involving a similar material and sheet thickness combination with static loads.
Design of Decoupled and Dynamically Isotropic Parallel Manipulators With Five Degrees of Freedom
Authors: Singh Yogesh Pratap , Ghosal Ashitava
Published: November 2022

A six degree of freedom (DOF) two-radii Gough-Stewart Platform (GSP) can be designed to be dynamically isotropic and has been proposed for micro-vibration isolation. In many applications, the torsional mode can be ignored, and a 5-DOF dynamically isotropic, parallel manipulator capable of attenuating three translational (3T) and two rotational (2R) modes are sufficient. In this work, we present the design of a novel two radii, 5-DOF dynamically isotropic parallel manipulator, which can be used for vibration isolation purposes where the torsion mode can be ignored. We present closed-form solutions in their explicit form to this design problem, and these are obtained using a geometry-based approach. The first design is based on a modification to the two radii GSP and provides enhanced design flexibility and feasibility. The second design of a decoupled 5-DOF GSP is based on superposing two 3-DOF dynamically isotropic or decoupled parallel manipulators, which are the well-known 3-3 RPS parallel manipulators. The closed-form solutions for these 3-DOF isotropic designs are obtained. It is shown that the 5-DOF decoupled design have two translational modes, namely the (X, Y) modes, which are decoupled from two rotational modes (Rot(X), Rot(Y)) and are controlled by two different sets of three struts. This feature can lead to simpler control and less power requirements if active vibration control is chosen. The designs presented in this work include the effect of asymmetricity and payload’s centre of mass variation in the moving platform. The dynamically isotropic and decoupled designs obtained were successfully validated using the finite element software ANSYS®.
Framework Design of a Digital Twin of an XY Compliant Parallel Manipulator Based on Non-Negative Matrix Factorization
Authors: Song Xueguan , Li Kunpeng , Wang Shuo , Kan Ziyun , Li Haiyang , Zhu Jiaxiang , Hao Guangbo
Published: November 2022

A promising multi-layer mirror-symmetry XY compliant parallel manipulator (CPM) has been recently reported to address the tradeoff between a small compact footprint and a minimized parasitic rotation. In order to scientifically ensure the healthy operation of equipment and make maintenance decisions reasonably, there is a need to depict its physical mechanical characteristics in a virtual space instantaneously. The digital twin, an emerging technology, can be used to address this need by achieving a seamless convergence of physical and virtual spaces for this XY CPM. However, the high accuracy and instantaneousness requirements have hindered the application and popularization of the digital twin. This article presents a framework to build an accurate and lightweight digital twin, and in the meanwhile significantly reduces the computational budget (i.e. high computation efficiency). The framework is validated by an XY CPM test apparatus. The results demonstrate that the proposed framework is an effective tool to build an accurate and lightweight digital twin for the XY CPM, which is also promising for other compliant mechanisms or parallel manipulators.
Design of Customized Noncircular Chainrings for Cycling
Authors: Polanco Alejandra , Duran Jose , Muñoz Luis , Sabogal Santiago
Published: November 2022

Noncircular chainrings have drawn the attention of the cycling community because they are designed to improve the pedaling cycle and obtain better performance. Nevertheless, there is no general agreement on their effect; for this reason, they are still under development, and further efforts to understand and improve this component are required.

In this work, a noncircular chainring with custom geometry was designed, manufactured, and tested. A numerical model was developed to study the effect of the chainring geometry on the mechanical advantage of the bicycle transmission system. A chainring with a custom geometry was designed to be manufactured. The manufactured chainring was installed on a road bicycle, and its mechanical advantage was measured through motion capture.

A custom noncircular chainring providing the target mechanical advantage profile was obtained. CNC machining was used for manufacturing the 1:1 scale functional prototype. The prototype was constructed in Aluminum 7075T6. The prototype was based on an elliptical geometry with 52 teeth. The ellipse used for the prototype had a minor axis of 97.60 mm and a major axis of 118.77 mm. The results of the experimental characterization of the chainring prototype showed a variation in the mechanical advantage obtained along a pedaling cycle within 0.194 and 0.233.
Nuclear Batteries Enable Decades of Uninterrupted Life for Microelectronic Systems
Authors: Barham Oliver M.
Published: November 2022

Nuclear radioisotope batteries are a class of energy dense power sources that convert radioactive decay particle energy directly into electricity for powering sensors, electronics, and medical implants in applications where battery replacement is difficult or impossible. In order to show the potential benefits of integrating these types of power sources into microelectronic sensor systems, three recent examples from the literature are considered: a gas sensor; a communication component (radio frequency front-end); and a photoplethysmographic sensor. These were selected to represent three common microsystem components: environmental sensors; communication components; and biological sensors. In each case, system operational lifetime is computed when powered with a commercial Li-ion coin cell battery, followed by a comparison with three nuclear battery prototypes from the literature. In each case, the nuclear power sources allow potential continuous, unattended operational life to be extended by an order of magnitude or more, typically from less than one year to decades of continuous use. Advantages and disadvantages of nuclear batteries in general are also addressed.
Periodic Composite Function-Based Designing of Microstructures With Programmable Poisson Ratio
Authors: Zhang Yilong , Du Yuxuan , Qiao Ye , Wang Shu , Wang Cunfu
Published: November 2022

Advances in additive manufacturing enable rational design and fabrication of multiscale architectures composed of microstructures with extreme mechanical properties. The parameterization of microstructures determines the computational cost for rational design and connectivity between different microstructures, in turn, the mechanical performance of the fabricated multiscale architectures. In this paper, we propose a periodic composite function (PCF)-based approach for designing microstructures. The shape of the microstructures is characterized by the sign of the periodic composite functions. The proposed method can program Poisson’s ratio of the microstructures with a small number of parameters. Furthermore, due to its implicit representation, the proposed method allows for continuously tiling of microstructures with different mechanical properties. As such, by designing the distribution of the scalar parameters, we are able to project spatially varying microstructures onto an object of arbitrary geometry and control its deformation. Based on the proposed approach, multiple groups of microstructures with Poisson’s ratio ranging from negative to positive are presented. Numerical examples are also presented to demonstrate the efficacy of the proposed approach in controlling elastic deformation through spatially varying microstructures. Due to its compact representation, the proposed method can be readily reproduced by other researchers and extended to practical applications in designing two-scale architectures for additive manufacturing.