Side Door Research Articles

Endoscopic ultrasound-guided pancreaticoduodenostomy using a lumen-apposing metal stent as a primary approach to treat difficult pancreatolithiasis: creating a side door to unlock the front door

Endoscopic ultrasound-guided pancreaticoduodenostomy using a lumen-apposing metal stent as a primary approach to treat difficult pancreatolithiasis: creating a side door to unlock the front door

Clarification of appropriate conditions for forming complex shapes with multiple steps in two-stage deep drawing process

In this study, appropriate conditions for forming complex shapes with multiple steps, such as automotive side door inner in a two-stage deep drawing process are investigated, and the effectiveness of the process is verified in a test. In this forming process, the inner area of the part is formed in the first stage and the outer area is formed in the second stage. And in the second stage, a forming pad is used to reduce strain in the inner area that is formed in the first stage. The results of the forming test showed that it is necessary to control the blank holding force (BHF) and the pad force (PF) in the second stage to avoid blank ruptures in all areas. Therefore, the concept of the BHF and PF for blank rupture risk at each site was studied using the finite element method (FEM). An appropriate range of BHF and PF was estimated from the results of FEM and the validity of the estimated values was confirmed in an actual test. In addition, it was confirmed that a two-stage deep drawing process using the above appropriate values can form a more severe shape than a one-stage deep drawing process.

Determination of a car speed - analysis of projectile motion from a muddy puddle

Drops from a muddy puddle produce a distinct pattern on the side doors of a car driving through the puddle. This pattern was studied to determine the speed of the car. We can conceive at least two different models for pattern formation. We can decide in favor of one of the models by using different representations of the data. The activity is based on a rich context-based problem of projectile motion and offers epistemological insight into how physics research works by forming and testing hypotheses and using alternative representations.

Numerical analysis of injuries of e-scooter riders in frontal impacts against SUVs

The rising popularity of e-scooters in urban areas highlights the importance of understanding potential collision dynamics and consequences to enhance rider safety, especially since 80% of fatalities for these vulnerable road users result from incidents involving motor vehicles. This study aims to identify potential injury mechanisms of e-scooter riders involved in frontal impacts against Sports Utility Vehicles (SUVs) using Finite Element Analysis (FEA) and a Human Body Model (HBM). Six impact scenarios at 25 km/h were simulated: on the passenger's side door (1-SD), on the trunk door (2-TD), on the bonnet (3-FB), on the bonnet from the side (4-SB), on the windshield from the side (5-SW), and finally, on the bonnet with an offset (6-FO). A wide range of Injury Risk Criteria (IRCs) was analyzed, including A3MS, HIC15, BrIC, DAMAGE, Cmax and PC Score, and head contact forces were output. Injury Risk Curves were then used to calculate the probability and severity of the sustained injuries predicted by the mentioned IRCs. Overall, the results corresponding to the most injurious scenarios suggested serious (30% to 40% overall probability) and critical (45% probability for the 4-SB scenario) brain, moderate head (30% probability for scenarios 1-SD and 2-TD), and serious thoracic (26% to 78% overall probability) injuries. Additionally, in two scenarios (1-SD and 2-TD), the e-scooter rider's mandible impacted against the vehicle's roof side rail and rear spoiler, involving potential anterior-posterior serious mandible fractures. The conclusions reached in this study help to understand potential injury sources and provide valuable information for the design of specific safety systems or the creation or improvement of e-scooter legislation.

Research on a novel compliant mechanism applied in the vehicle side door latch and stability analysis via Lyapunov exponents

The functional reliability of the vehicle latch is very important and is determined by the internal mechanism’s motion stability. In this paper, a novel compliant mechanism constructed with a novel compliant joint is applied to the vehicle latch, and multiple mode motions of the mechanism realize the newly added electric power release function. The repeatability of mechanism trajectories and phase diagrams of several different periodic motions is creatively regarded as the stability of the compliant mechanism. In this compliant mechanism, the endpoint of the groove-coupler is chosen as a characteristic point and the compliant joint’s spring stiffness kT is taken as the key parameter to obtain trajectories and phase diagram. It is found that all cycle overlapping phase diagrams possess intuitively good repeatability, except in two locally specific regions. Then, Wolf’s numerical calculation method of Lyapunov exponents is utilized to analyze the motion stability of the compliant mechanism. An appropriate range (1.0–1.05 N mm/°) of the joint stiffness kT is obtained, satisfying the stability criterion. Finally, characteristic point trajectory and functional experiments with kT = 1 N mm/° are conducted to verify the motion stability of the compliant mechanism. The method of mechanism motion stability analysis by means of Lyapunov exponents can be applied to other under-actuated mechanisms.

A Wind Protection Design Strategy for Airport Terminal Door Bucket Space Based on Wind Environment Simulations

Airport terminal buildings are large public transportation buildings with complex functions and dense crowds, and the wind environment has significant effects on passenger comfort and the energy consumption of air conditioning systems. In this study, we investigated Xianyang T3 Terminal as an example and used the Phoenics software to conduct comprehensive simulations based on different door bucket forms and parameters, as well as comprehensively considering the impacts of different outdoor wind environments. A terminal door bucket windproof design strategy was proposed based on our results. The results showed that door buckets could effectively reduce the entry of outdoor wind, and built-in door buckets performed the best. The width of the door bucket should be set to 9.3–11.3 m and the depth of the door bucket to 6.7–7.7 m. The height of the door bucket had little impact. A side door should be added to the door bucket, so it can be opened when the outdoor wind speed is high, and a mechanical ventilation system should be introduced to improve the indoor ventilation.

Analytical studies on effects of wind on dispersion of hydrogen leaked in a partially open space

ABSTRACT In order to elucidate ventilation and exhaust of hydrogen (H2) leaked in a partially open space (room) practically, the effects of outer wind (forced external flow) on them were studied analytically by using a CFD (computational fluid dynamics) code in the room of experimental ‘Half-size Hallway model (1/2 Hallway model),’ which has a H2 release hole on the bottom, one vent on the roof (Roof vent) and another vent on the side (Door vent): external air flowed in the room from the Door vent and then H2 was discharged outside from the Roof vent. The H2 concentration distribution in the room was divided into two layers at the height of Door vent, with a high concentration layer above it and a low concentration layer below it, forming a stratified interface. When the wind speed blown into the room increased, the combination of the Realizable k-ε turbulence model and the turbulence Schmidt number of 1.0 improved the reproducibility of the analysis results of H2 concentration distribution. The trial analysis suggested that the concern that wind would increase the indoor H2 concentration could be reduced by using the plate with a simple structure in which two plates were crossed on the Roof vent.

Integrated Costs and Environmental Impacts Optimization for Production of a Multi-Material Component

Choosing environmentally benign strategy in product manufacturing is a relevant need that has been influencing all the industrial sectors aiming at reduction of greenhouse gas emissions. This necessity often collides with the production costs. A different design strategy based on a multi-material approach can result in an economic efficiency playing, at the same time, a fundamental role in reducing the environmental footprint. Taking into account this scenario, an optimisation study was proposed focusing on the minimisation of both costs and environmental impacts of a car's lead anti-intrusion side door inside beam (SDIB) manufactured using a multi-material approach. The materials takeable into account in the executed design strategy were a carbon steel, an aluminium alloy, and a carbon fibre reinforced polymer. The objective of the work was to find a balance between cost efficiency and environmental sustainability throughout the entire product life cycle. Specifically, the input variables in the optimisation analysis were energy consumption, CO2 emissions, resource use and direct production costs. The model was developed taking these multiple factors into account and making possible the minimisation of costs and environmental impact, simultaneously respecting, at the same time, the required product performance.

Development of a Side Door Composite Impact Beam for the Automotive Industry

Development of a Side Door Composite Impact Beam for the Automotive Industry

Experimental exploration of mechanical behaviour of graphene oxide blend polymer nanocomposites

Purpose This study aims to evaluate the development of composites made of epoxy (E) resin with different weight percentages of polypropylene (PP) and graphene oxide (Go) to form nanocomposite plates. Design/methodology/approach A hand lay-up process was used to develop 21 different composites, with varying concentrations of PP (5%–35%) and Go (5%–35%). A ternary composite of E matrix was produced by combining binary fillers PP and Go (5%–35%) in a 1:1 ratio to a (95%–5%) solution. With the help of adopting the melt condensation deal to extract Go, the modified Hummers method was used to make Go platelets. Findings Through field emission scanning electron microscopy (FESEM) and X-ray diffraction investigations, the particulate’s size and structural characteristics were identified. Based on the FESEM analysis of the collapsed zones of the composites, a warp-and-weft-like structure is evident, which endorses the growth yield strength, flexural modulus and impact strength of the composites. Originality/value The developed nanocomposites have exceptional mechanical capabilities compared to plain E resin, with E resin exhibiting better tensile strength, modulus and flexural strength when combined with 10% PP and 10% Go. When compared to neat E resin, materials formed from composites have exceptional mechanical properties. When mixed with 10% PP and 10% Go, E resin in particular displays improved tensile strength (23 MPa), tensile modulus (4.15 GPa), flexural strength (75.6 MPa) and other attributes. Engineering implications include automobile side door panels, spacecraft applications, brake pads and flexible battery guards.

Shifting equality from the margins: the Common European Asylum System and the making of trans rights in the European Union

This article investigates the role played by the main European cooperation mechanism on asylum, the Common European Asylum System, in the making of lesbian, gay, bisexual, trans and intersex rights in the European Union. Based on a one-year qualitative inquiry in Brussels and online, it shows that European Union asylum policies were a key arena for the consolidation, invention and renegotiation of European Union lesbian, gay, bisexual, trans and intersex rights, especially concerning trans recognition. This pioneering role, far from being fortuitous, was part of the conscious strategy of the lesbian, gay, bisexual, trans and intersex movement to use asylum as a ‘side door’ to the creation of a de facto recognition of ‘gender identity’ as a protected characteristic. Characterising this phenomenon as a ‘politics of interstices’ and analysing the importance of ignorance (and not just knowledge) as a tool for policy change, this article makes the case for an analysis of policymaking that acknowledges the importance of non-equality-specific arenas in the making of equality norms.

3D pollination biology using micro-computed tomography and geometric morphometrics in Theobroma cacao.

Imaging technologies that capture three-dimensional (3D) variation in floral morphology at micro- and nano-resolutions are increasingly accessible. In herkogamous flowers, such as those of Theobroma cacao, structural barriers between anthers and stigmas represent bottlenecks that restrict pollinator size and access to reproductive organs. To study the unresolved pollination biology of cacao, we present a novel application of micro-computed tomography (micro-CT) using floral dimensions to quantify pollinator functional size limits. We generated micro-CT data sets from field-collected flowers and museum specimens of potential pollinators. To compare floral variation, we used 3D Slicer to place landmarks on the surface models and performed a geometric morphometric (GMM) analysis using geomorph R. We identified the petal side door (an opening between the petal hoods and filament) as the main bottleneck for pollinator access. We compared its mean dimensions with proposed pollinators to identify viable candidates. We identified three levels of likelihood for putative pollinators based on the number of morphological (body) dimensions that fit through the petal side door. We also found floral reward microstructures whose presence and location were previously unclear. Using micro-CT and GMM to study the 3D pollination biology of cacao provides new evidence for predicting unknown pollinators. Incorporating geometry and floral rewards will strengthen plant-pollinator trait matching models for cacao and other species.

Contralateral Hip Abductor Muscle Strength Associated with Comfort of Getting into and out of the Car after Total Hip Arthroplasty.

There are no studies that have investigated the characteristics of car use across THA patients, including those who do not drive. This study aimed to evaluate, in THA patients, (1) postoperative car usage, (2) comfort while entering and exiting a car, and (3) whether lower limb muscle strength affects action comfort. One hundred seventy-two post-THA patients completed the questionnaire in 2020, along with assessments of hip abductor and knee extensor muscle strength before surgery and at discharge. Patients whose overall comfort level was judged as comfortable were defined as the comfort group; others were placed in the discomfort group. Of the 172 patients, 161 reported car usage at a mean of 5.6 years after THA. Of these, 114 and 47 patients were placed in the comfort and discomfort groups, respectively. Patients in the discomfort group were three times more likely to experience discomfort using the contralateral side door than the surgical side door, and about twice as many patients experienced discomfort when entering as when exiting. Lower preoperative contralateral hip abductor muscle strength was the only independent predictor for discomfort. The take-home messages were that prevention of contralateral-side weakness may improve comfort during the action after THA.

A methodology for crash investigation of motorcycle-cars collisions combining accident reconstruction, finite elements, and experimental tests

Motorcycle and in general motorized 2–3 wheelers accidents are a major concern of road safety worldwide representing about 28% of the overall fatalities. Speed is a central factor in the increase of injury severity of the accident’s intervenients. The main factors and causes of an accident can be determined with accident reconstruction being the reason for its popularity in accident safety research. A methodology of three different and complementary accident reconstruction methods is proposed and applied to a real accident where a motorcycle impacts the front side door of a passenger car. No other study in the literature presents a similar methodology for motorcycle accident reconstruction. With PC-Crash all accident dynamics were determined in the first place with a complete accident reconstruction. Afterwards, a finite element simulation of the impact between the motorcycle tire and the car’s door was conducted in Ansys LS-DYNA using all the results extracted from PC-Crash. The results of both these analyses correlated well with reality. To validate the finite element model, a pendulum experimental impact test was performed. It was achieved a good correlation from a kinematic point of view. An accurate accident reconstruction and a correct validation of the kinematics are possible with the proposed methodology. A good correlation of results between the three different methods was achieved. The proposed methodology enables for a more accurate estimation of the speed of motorcycles involved in accidents which is of extreme importance in accident investigation.

Incremental design process for vehicle structural components using thermoplastic-based composites: A simulation-guided approach for door anti-intrusion beams

The design of safety-related structural components in automobiles is a critical phase. Most car manufacturers are aiming at reducing vehicle weight considering continuous fiber-reinforced thermoplastics as candidate to replace metal-based structural components. However, this replacement cannot compromise the safety level already achieved by metal-based designs. A good example is the side door anti-intrusion beam, which is a passive safety component to protect the passengers under a lateral impact. This paper presents an incremental design process to achieve a functional side door anti-intrusion beam fully made of glass fiber reinforced thermoplastic conceived to replace metal-based ones. The reader is guided along the design challenges, where the mechanic-based reasons to adapt the part geometry and composite layout are explained in detail. This incremental design process uses a fully FEM-based approach allowing to reach a standard-defined absorbed energy of 1000 J in a lateral collision. From the simulation analysis, it was found that by implementing essential modifications in the beam’s cross-section corrugation, the damage progression can be slowed down leading to an increase of absorbed energy. Additionally, the enhancement of one extra ply in the proper direction solves severe fracture in the clamping area. The final composite design not only performs similarly to its metal-based counterpart, but also considers aspects of production feasibility. This trip along the design process concludes with the production of the simulate-designed component and its effectiveness under lateral impact is demonstrated. To meet the safety regulations, the model is thoroughly validated against the real impact test by analyzing the response in force, intrusion, energy and damage.

The stakes of abyssal geography. Response to commentaries on David Chandler and Jonathan Pugh's ‘Abyssal geography’.

The stakes of abyssal geography. Response to commentaries on David Chandler and Jonathan Pugh's ‘Abyssal geography’.

Navigational water resistance analysis and optimization of the gondola of unmanned boat retractable device

Combining the characteristics of the existing transfer slideway and double-point hanging type two retractable devices, this paper proposes a multiple-point hoisting, fast transfer, and retractable device. According to the viscous flow theory, one-way fluid-structure interaction simulation is used for the gondola structure of the unmanned boat retractable device. Considering the influencing factors of the width of the gondola, the void ratio, the shape and distribution of the void, and the deployment angle of the guardrail, the navigation water resistance of each model is compared and analyzed, and the optimal design of the gondola device is discussed. The results show that the increase of the top width and the decrease of the front-end void ratio will lead to an increase in the water resistance of the gondola; under the same porosity, the rectangular shape performs better than the circular shape, and the smaller interval between the rectangles is more conducive to reducing the water resistance of the gondola; the increase in the angle of the side door guardrail of the gondola will lead to an increase in the navigation water resistance; the final optimized design of the gondola device meets the strength requirements under extreme conditions of high sailing speed.

Analysis of injury mechanism and thoracic response of elderly, small female PMHS in near-side impact scenarios

Objective In 2020, 17% of all crash fatalities were individuals aged 65 years or older. Crash data also revealed that for older occupants, thoracic related injuries are among the leading causes of fatality. Historically, the majority of near-side impact postmortem human subjects (PMHS) studies used a generic load wall to capture external loads that were applied to PMHS. While these data were helpful in documenting biofidelity, they did not represent a realistic response an occupant would undergo in a near-side crash. The objective of this research was to test small, elderly female PMHS in a repeatable, realistic near-side impact crash scenario to investigate current injury criteria as they relate to this vulnerable population. Method Ten small, elderly PMHS were subjected to a realistic near-side impact loading condition. The PMHS were targeted to be elderly females age 60+, approximately 5th percentile in height and weight, with osteopenic areal bone mineral density. Each subject was seated on a mass-production seat, equipped with a side airbag and standard three-point restraint with a pretensioner. Other boundary conditions included an intruding driver’s side door. PMHS instrumentation included strain gages on ribs 3-10 bilaterally to identify fracture timing. Two chestbands were used to measure chest deflection, one at the level of the axilla and one at the level of the xiphoid process. Results Injuries observed included rib fractures, particularly on the struck side, and in multiple cases a flail chest was observed. Eight of ten subjects resulted in AIS3+ thoracic injuries, despite previously tested ATDs predicting less than a 10% chance of AIS3+ injury. Subjects crossed the threshold for AIS3 injury in the range of only 1% − 9% chest compression. Additionally, mechanisms of injury varied, as some injuries were incurred by door interactions while others came during airbag interactions. Conclusions This research points to two areas of concern that likely require further analysis: (1) the appropriateness of potentially oversimplified PMHS testing to establish injury thresholds and define injury criteria for complicated crash scenarios; (2) the importance of identifying the precise timing of injuries to better understand the effect of current passive restraint systems.

Analysis and Optimization of Automotive Self-Priming Door Lock Closing Sound

<div>With higher customer expectations and advances in vehicular technology, automotive functions and operations are becoming more intelligent. Electric self-priming door locks fulfil the automatic closing and locking of side doors, hatchback doors, sliding doors, liftgates, decklids, etc. They are widely implemented into high-end models for the elegance of soft closing. In the list of perceived vehicle qualities, door-closing sound quality has been one of the important customer concerns in the market. In comparison to conventional door locks, electric self-priming door locks add another dimension to the development of sound quality for noise, vibration, and harshness (NVH) efforts. In this article, the characteristics of door-closing sound involving self-priming door lock mechanisms are analyzed and illustrated. Human perception of different sounds from the self-priming door lock working process is ranked by subjective evaluations. For typical door closing sounds associated with the self-priming lock mechanisms, i.e., the motor sound and rebound sound, real-case examples are discussed. A case of the buzzing noise issue due to the self-priming lock on a hatchback door is also presented. In these cases, the correlation between the sounds and the structure of the self-priming door locks is investigated and the root causes of the encountered issues are identified. The door closing sound quality associated with the self-priming door locks is improved in each case to meet the program requirements. In the particular cases presented in this work, the analysis involves psychoacoustic metrics for sound quality study originally. It is found later that sound pressure level can address the encountered issues, and thus only sound pressure level results are included.</div>

Uniportal video-assisted thoracoscopic combined subsegmentectomy: a case report of left S3b + S4b

: Anatomical complex segmentectomy has become increasingly important in oncological lung resection, particularly for small ground-glass nodules of primary lung cancers. Resection of a lung nodule located between the left upper division and the lingual segment is technically challenging. Delicate surgical planning is crucial to ensure adequate surgical margin while preserving maximum pulmonary function. A combined subsegmentectomy can be a feasible choice but is challenging to perform under uniportal approach due to limited working space and insufficient exposure of target segmental bronchi and pulmonary arteries. The purpose of this article is to introduce the technique we use to overcome these challenges. Herein, we report a case with two ground-glass nodules in the left upper lobe, one 0.6-cm adjacent to the V3b and one 0.4-cm beneath the S4b surface. Instead of extended upper division trisegmentectomy or extended lingulectomy, a uniportal video-assisted thoracoscopic S3b + S4b combined subsegmentectomy was planned and performed. Three-dimensional computed tomography reconstruction was performed preoperatively to reveal the branching pattern of the associated sub-segmental bronchi and pulmonary vessels. Inflation-deflation method was applied to identify intersegmental planes, and both lesions were removed successfully. We describe our “open the side door” technique for performing subsegmentectomy in this patient. This technique is helpful when performing a complex subsegmentectomy.