Types Of Junctions Research Articles

The Tunnel Type Road Interchange Vulnerability Assessment Model

At present, both in Russia and abroad, a new line of work is developed to comprehensively automate the functions of monitoring and controlling security systems, life support and technological processes of potentially dangerous, unique and technically complex objects (high-risk objects), which can also include car interchanges tunnel type. However, these works are unsystematic and do not fully solve the prevention and liquidation issues of emergency situations at the above-mentioned facilities. Moreover, in case of incorrect design of the above-mentioned systems, they can contribute to the deaths of people on the site and beyond. This is confirmed by the accidents’ statistics at these facilities including the road junctions of the tunnel type. The accidents causes’ analysis at high-risk facilities showed that they are largely stipulated by the incorrect definition of vulnerability (threats) assessment for the designed facilities and the facilities under construction. Thus, the model development for assessing the vulnerability of tunnel-type road junctions is an urgent task. To achieve this goal, the main causes of emergencies at tunnel type road junctions are considered and based on them, using a system analysis method and experimental theory, a three-dimensional model that allows, with the expert assessments, to determine the susceptibility of tunnels to various threats types, is developed and tested.

Modelling risk factors for red light violation in the Kumasi Metropolis, Ghana

Red light running places the violator and other road users at risk of road traffic crash. The aim of this research was to undertake a baseline study to establish the current rate of red light running in the Kumasi Metropolis, Ghana and to determine the associated risk factors. An uninterrupted road side observational survey was conducted at 10 signalized intersections using pro-forma checklist. A binary logit model was employed to determine the risk factors associated with traffic light violations. Overall, drivers were observed running the red light in 35% of all the red phases studied. From the statistical model, red light running was found to be influenced by the age and gender of the driver, presence of a passenger in the vehicle, vehicle type, junction type, cycle length of the signal and queue length. There is a need for targeted public awareness campaigns on the dangers of red light running. The education on red light violation must be accompanied by sustained Police enforcement of the traffic law to reduce the rate of violation. Automatic surveillance cameras should be installed at all critical signalized intersections to supplement Police efforts to enforce traffic safety laws and regulations.

Tutorial review: Enrichment and separation of neutral and charged species by ion concentration polarization focusing

Ion concentration polarization focusing (ICPF) is an electrokinetic technique, in which analytes are enriched and separated along a localized electric field gradient in the presence of a counter flow. This field gradient is generated by depletion of ions of the background electrolyte at an ion permselective junction. In this tutorial review, we summarize the fundamental principles and experimental parameters that govern selective ion transport and the stability of the enriched analyte plug. We also examine faradaic ICP (fICP), in which local ion concentration is modulated via electrochemical reactions as an attractive alternative to ICP that achieves similar performance with a decrease in both power consumption and Joule heating. The tutorial covers important challenges to the broad application of ICPF including undesired pH gradients, low volumetric throughput, samples that induce biofouling or are highly conductive, and limited approaches to on- or off-chip analysis. Recent developments in the field that seek to address these challenges are reviewed along with new approaches to maximize enrichment, focus uncharged analytes, and achieve enrichment and separation in water-in-oil droplets. For new practitioners, we discuss practical aspects of ICPF, such as strategies for device design and fabrication and the relative advantages of several types of ion selective junctions and electrodes. Lastly, we summarize tips and tricks for tackling common experimental challenges in ICPF.

High tunnelling electroresistance in a ferroelectric van der Waals heterojunction via giant barrier height modulation

Ferroelectric tunnel junctions use a thin ferroelectric layer as a tunnelling barrier, the height of which can be modified by switching its ferroelectric polarization. The junctions can offer low power consumption, non-volatile switching and non-destructive readout, and thus are promising for the development of memory and computing applications. However, achieving a high tunnelling electroresistance (TER) in these devices remains challenging. Typical junctions, such as those based on barium titanate or hafnium dioxide, are limited by their small barrier height modulation of around 0.1 eV. Here, we report a ferroelectric tunnel junction that uses layered copper indium thiophosphate (CuInP2S6) as the ferroelectric barrier, and graphene and chromium as asymmetric contacts. The ferroelectric field effect in CuInP2S6 can induce a barrier height modulation of 1 eV in the junction, which results in a TER of above 107. This modulation, which is shown using Kelvin probe force microscopy and Raman spectroscopy, is due to the low density of states and small quantum capacitance near the Dirac point of the semi-metallic graphene. A ferroelectric tunnel junction that uses copper indium thiophosphate as the ferroelectric barrier, and graphene and chromium as asymmetric contacts, can offer a high resistance ratio between on and off states.

Plasmonic-enhanced light emission from a waveguide-integrated tunnel junction

Light emission from inelastic electron tunneling has been demonstrated for 40 years. The ultrafast response rate and the ultracompact footprint make it promising for high-speed miniaturized light sources. But the application of the tunnel junction is limited by extremely low external quantum efficiency due to the low proportion of inelastic tunneling electron and wave vector mismatch between surface plasmons and photon emission. Here, we present a plasmonic-enhanced metal-insulator-semiconductor (MIS) junction coupled to a silicon waveguide with a coplanar electrode connected to a nanoantenna. The proposed tunnel junction can be fabricated using existing semiconductor planar processes to achieve controllable barrier thickness and quality for vertical current injection. Finally, an electrically driven light source with a radiation power nearly 8000 times higher than the spontaneous emission power in free space is shown to be achievable with the new structure at an operating wavelength of 1.31 µm. It is 510-fold higher than that of typical planar MIS junctions.

Traumatic Fracture: Dislocation of Cervicothoracic Junction—Grand Round Presentation of C7-T1 Instabilities and Different Instrumentation Techniques

Introduction Acute traumatic cervicothoracic junction spinal lesions are rare disorders and poorly documented. We report a case of a traumatic cervicothoracic fracture-dislocation. We present our experience in the operative treatment of an unstable fracture-dislocation at the cervicothoracic junction. Materials and Method. A seventy-year-old man was transferred to our hospital. We found paresthesia in the corresponding dermatome of C7 and C8 bilaterally. Initial CT scan shows vertebral body fracture of T1 with retropulsion into the spinal canal and anteroposterior dislocation of cervicothoracic junction type C according to AOSpine subaxial injury. Traumatic disc material at C7-T1 was removed by anterior cervical discectomy and fusion of C6-T2. Fixation was done from C6 to T2 in the prone position. Results At one-year postoperative follow-up, radiographs revealed bony fusion at the level of C7-T1, and the patient had no major functional disability. Conclusion We opted for the ventral-dorsal approach in our case for maximum stabilization and to prevent mechanical complications.

Periodic in time flow in thin structure: Equation on the graph

The dimension reduction for the non-stationary time periodic Navier-Stokes equations in thin structures leads to a non-local in time Reynolds' type equation on the graph with Kirchhoff type junction conditions in the vertices. The existence and uniqueness of a solution to this problem is proved.

Optical and electrical optimization of all-perovskite pin type junction tandem solar cells

A definitive breakthrough of perovskite solar cells towards large scale industrialization is believed to be the demonstration of higher efficiencies than conventional silicon technology, suggesting the exploration of perovskite tandem cell configurations. Since high efficiency tandem solar cells require careful optimization of photoactive as well as contact and additional functional layers, we propose an optical-electrical model to obtain the optimum layer thicknesses and the attainable electrical output parameters of two-terminal perovskite-perovskite tandem solar cells. The optical model takes into account the coherent propagation of light through the layer stack comprising two perovskite semiconductors and the corresponding contact layers, while the electrical model assumes two series-connected analytical current/voltage equations for pin solar cells. This model allows to assess the impact of the main physical parameters on each perovskite layer without requiring the high specificity needed in more rigorous numerical simulations. Efficiencies above 34% are predicted considering available perovskites with non-optimum bandgap and contact materials already proven in efficient laboratory solar cells. The requisite to attain such efficiencies is that recombination at the interfaces between the perovskite and contact materials is kept low in both bottom and top cells. Furthermore, within the assumption of non-optimum bandgaps of currently available perovskites, the simulation results suggest that efficiencies around 37% are possible when adopting contact materials with smaller absorption, more adequate refraction indices, and lower resistivity.

Computed Tomography Scan Assessment of the Anatomy of the Pterygomaxillary Junction and Its Relevance in Le Fort I Osteotomy.

Knowledge of the morphometry and types of pterygomaxillary junction (PMJ) during Le-Fort I osteotomy is an important consideration in the reduction of intraoperative complications. The PMJ is known to display population variations and with the recent increase in these surgical interventions in Kenya, a detailed description of the PMJ is warranted. Computed tomography scan images of PMJ obtained from 63 patients were analyzed at the level of the posterior nasal spine to assess types and the morphometry of the PMJ. A fissure type of PMJ was present in 65.9% (83/126 sides) while a synostosis type was present in 34.1% (43/126). Bilateral fissures were found in 58.73% (37/63), bilateral synostosis in 26.98% (17/63), and an asymmetric PMJ in 15.25% (9/63). The average height, width, and thickness of the PMJ were 17.45 ± 5.26 mm, 10.24 ± 1.97 mm, and 6.40 ± 1.97 mm respectively. Males had a significantly greater height (P = 0.003) and width (P = 0.000). The average width was greater in cases with a synostosis as compared with those with a fissure (P = 0.019). Average distance of greater palatine canal was 40.41 ± 2.28 mm and 7.19 ± 2.20 mm from the piriform rim and the pterygoid fossa respectively. The PMJ among Kenyans is characterized by a higher occurrence of synostosis, greater height, and thickness compared with previous findings from other populations. The results of this study can be helpful for surgeons in selecting the most appropriate techniques to achieve successful pterygomaxillary disjunction and minimize avoid attendant complications such as vascular and nerve injuries.

Topological junction states and their crystalline network in systems with chiral symmetry: Application to graphene nanoribbons

We develop a general theoretical framework based on $Z$ classification to count the number of topological bound states at a junction of chiral-symmetric one-dimensional systems. The formulation applies to general multiway junctions composed of an arbitrary number of channels and an arbitrary joint structure. By using the formula, we calculate the zero-energy bound states in various types of two-way and three-way junctions of semiconducting graphene nanoribbons. We then consider periodic two-dimensional networks of graphene nanoribbons and show that the topological junction states form isolated energy bands inside the bulk energy gap, which can be viewed as a two-dimensional crystal of the effective atoms. Depending on the $Z$ number of a single junction, we have a different set of effective atomic orbitals, resulting in various types of nanoscale metamaterials, which are often accompanied by flat bands. The system would provide an ideal platform for quantum simulator to emulate a strongly-interacting fermion system on various types of lattices.

Design and testing of an innovative 3D-printed metal-composite junction

This paper describes an innovative 3D-printed beam-based lightweight structure that is used to increase the adhesion strength of metal-composite joints without damaging the composite fibers. It is conceived as the interface between the two parts to be joined: by filling the voids of this structure with resin, a mechanical interlocking effect can be generated to enhance the mechanical properties of the junction. A dedicated design workflow was defined to explore different types of 3D beam-based structures, starting from the analysis of the main failure modes of this type of junction. Tensile tests were performed on both polymeric and metal samples to validate the effectiveness of this interlocking strategy. Results demonstrated an increase in the adhesion strength relative to standard adhesive joints. A possible practical implementation is also discussed: a new type of insert is presented for application in metal-to-polymer composite joints. Finally, such a beam-based joining approach also represents an innovative application in the field of design for additive manufacturing.

Volumetric modulated arc therapy versus intensity-modulated proton therapy in neoadjuvant irradiation of locally advanced oesophageal cancer

BackgroundTo investigate the role of intensity-modulated proton therapy (IMPT) compared to volumetric modulated arc therapy (VMAT), realised with RapidArc and RapidPlan methods (RA_RP) for neoadjuvant radiotherapy in locally advanced oesophagal cancer.MethodsTwenty patients were retrospectively planned for IMPT (with two fields, (IMPT_2F) or with three fields (IMPT_3F)) and RA_RP and the results were compared according to dose-volume metrics. Estimates of the excess absolute risk (EAR) of secondary cancer induction were determined for the lungs. For the cardiac structures, the relative risk (RR) of coronary artery disease (CAD) and chronic heart failure (CHF) were estimated.ResultsBoth the RA_RP and IMPT approached allowed to achieve the required coverage for the gross tumour volume, (GTV) and the clinical and the planning target volumes, CTV and PTV (V98% > 98 for CTV and GTV and V95% > 95 for the PTV)). The conformity index resulted in 0.88 ± 0.01, 0.89 ± 0.02 and 0.89 ± 0.02 for RA_RP, IMPT_2F and IMPT_3F respectively. With the same order, the homogeneity index for the PTV resulted in 5.6 ± 0.6%, 4.4 ± 0.9% and 4.5 ± 0.8%. Concerning the organs at risk, the IMPT plans showed a systematic and statistically significant incremental sparing when compared to RA_RP, especially for the heart. The mean dose to the combined lungs was 8.6 ± 2.9 Gy for RA_RP, 3.2 ± 1.5 Gy and 2.9 ± 1.2 Gy for IMPT_2F and IMPT_3F. The mean dose to the whole heart resulted to 9.9 ± 1.9 Gy for RA_RP compared to 3.7 ± 1.3 Gy or 4.0 ± 1.4 Gy for IMPT_2F or IMPT_3F; the mean dose to the left ventricle resulted to 6.5 ± 1.6 Gy, 1.9 ± 1.5 Gy, 1.9 ± 1.6 Gy respectively. Similar sparing effects were observed for the liver, the kidneys, the stomach, the spleen and the bowels.The EAR per 10,000 patients-years of secondary cancer induction resulted in 19.2 ± 5.7 for RA_RP and 6.1 ± 2.7 for IMPT_2F or 5.7 ± 2.4 for IMPT_3F. The RR for the left ventricle resulted in 1.5 ± 0.1 for RA_RP and 1.1 ± 0.1 for both IMPT sets. For the coronaries, the RR resulted in 1.6 ± 0.4 for RA_RP and 1.2 ± 0.3 for protons.ConclusionWith regard to cancer of the oesophagogastric junction type I and II, the use of intensity-modulated proton therapy seems to have a clear advantage over VMAT. In particular, the reduction of the heart and abdominal structures dose could result in an optimised side effect profile. Furthermore, reduced risk of secondary neoplasia in the lung can be expected in long-term survivors and would be a great gain for cured patients.

Continuous Eulerian tool path strategies for wire-arc additive manufacturing of rib-web structures with machine-learning-based adaptive void filling

Rib-web structures are used for lightweight design in various applications. The most prominent cases are found in aerospace engineering, where intricate structures are produced by forging and subsequent machining or by machining from solid blocks of material. Due to the large scrap rate involved in conventional manufacturing, rib-web structures are suitable applications for additive manufacturing (AM) processes. Among the AM processes, wire-arc additive manufacturing (WAAM) is highly suitable for rib-web structures due to its high deposition rate and the potential to manufacture large-size parts. In WAAM, the welding strategy greatly influences the properties and quality of deposited parts. With an increasing number of starts and stops, the danger of uneven material build-up and welding defects increases. Unfortunately, most rib-web structures do not represent Eulerian paths, i.e. they cannot be manufactured with a continuous welding motion, in which every edge is visited only once. This study presents a novel strategy for generating optimal tool paths for WAAM of lightweight rib-web structures, mitigating the disadvantages of discontinuous welding paths such as welding defects and uneven build-up. It is shown that doubling the number of welding passes on each edge of the rib-web structure turns non-Eulerian paths into Eulerian paths, which can be welded continuously. When two or more weld beads are deposited on each edge, the vertices of the rib-web structure may suffer from underfilling. It is shown that this can be avoided by a correction strategy, which consists in manufacturing the part once, evaluating the size of voids in the junctions, and computing a correction to deposit the required amount of material into the center of the junction. While this strategy may be used if a single part is considered, it is shown that the tool path correction to be applied to arbitrary junction geometries can be represented by a neural network that is derived from an experimental database consisting of representative junction types. With this approach, paths for any rib-web geometry can be generated, which saves lead time in variant-rich production. The paths proposed in this work avoid non-welding moves and may hence outperform even single weld-bed strategies in terms of welding efficiency.

Fine structure of the cardiac muscle cells in the orb-web spider Nephila clavata

The fine structural characteristics of cardiac muscle cells and its myofibril organization in the orb web spider N. clavata were examined by transmission electron microscopy. Although myofibril striations are not remarkable as those of skeletal muscles, muscle fibers contain multiple myofibrils, abundant mitochondria, extensive sarcoplasmic reticulum and transverse tubules (T-tubules). Myofibrils are divided into distinct sarcomeres defined by Z-lines with average length of 2.0 μm, but the distinction between the A-band and the I-bands is not clear due to uniform striations over the length of the sarcomeres. Dyadic junction which consisted of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum is found mainly at the A-I level of sarcomere. Each cell is arranged to form multiple connections with neighboring cells through the intercalated discs. These specialized junctions include three types of intercellular junctions: gap junctions, fascia adherens and desmosomes for heart function. Our transmission electron microscopy (TEM) observations clearly show that spider’s cardiac muscle contraction is controlled by neurogenic rather than myogenic mechanism since each cardiac muscle fiber is innervated by a branch of motor neuron through neuromuscular junctions.

EBSD characterization of pure and K-doped tungsten fibers annealed at different temperatures

Electron Backscatter Diffraction was used to investigate the grain boundary character and triple junction distributions as well as the microtexture on drawn pure and potassium doped (60–75 ppm) tungsten wires. With an approximate diameter of 150 μm, pure W wires were annealed at 1300, 1600 and 1900 °C, whereas K-doped material was annealed at 1300, 1600 and 2100 °C. The annealing was performed under hydrogen atmosphere for 30 min. Both longitudinal and transversal sections were analyzed to assess anisotropic features. Up to 1600 °C, all conditions presented a strong <110> fiber texture parallel to the drawing axis. With increasing annealing temperature, the pure W material developed a more heterogeneous fiber texture while for the K-doped material, it remained homogeneous. Orientation correlation function (OCF) analysis suggested sub-grain coarsening as the recrystallization mechanism while grain boundary density and grain boundary character distribution exhibited anisotropic behavior, as well as the triple junction distribution network. On the other hand, the coincidence site lattices (CSL) distribution did not present any anisotropy and followed the empirical law of the inverse cubic root of Σ-value. For all conditions, the most abundant CSL boundaries were Σ3, Σ9, Σ11, Σ17b, Σ19a, Σ27a and Σ33a. Based on the statistics of the triple junction types and their resistance to intergranular cracking, it was revealed that increasing the annealing temperature might play a role in crack deflection since the resistance to intergranular crack growth is increased in the transversal section and reduced in the longitudinal section. This anisotropic behavior is preserved up to a higher annealing temperature in the K-doped material.

Tracing the Evolutionary Origin of Desmosomes.

Cadherin-based cell-cell junctions help metazoans form polarized sheets of cells, which are necessary for the development of organs and the compartmentalization of functions. The components of the protein complexes that generate cadherin-based junctions have ancient origins, with conserved elements shared between animals as diverse as sponges and vertebrates. In invertebrates, the formation and function of epithelial sheets depends on classical cadherin-containing adherens junctions, which link actin to the plasma membrane through α-, β- and p120 catenins. Vertebrates also have a new type of cadherin-based intercellular junction called the desmosome, which allowed for the creation of more complex and effective tissue barriers against environmental stress. While desmosomes have a molecular blueprint that is similar to that of adherens junctions, desmosomal cadherins - called desmogleins and desmocollins - link intermediate filaments (IFs) rather than actin to the plasma membrane through protein complexes comprising relatives of β-catenin (plakoglobin) and p120 catenin (plakophilins). In turn, desmosomal catenins interact with members of the IF-binding plakin family to create the desmosome-IF linking complex. In this Minireview, we discuss when and how desmosomal components evolved, and how their ability to anchor the highly elastic and tough IF cytoskeleton endowed vertebrates with robust tissues capable of not only resisting but also properly responding to environmental stress.

Matrix metalloproteinase 9 facilitates Zika virus invasion of the testis by modulating the integrity of the blood-testis barrier.

Zika virus (ZIKV) is a unique flavivirus with high tropism to the testes. ZIKV can persist in human semen for months and can cause testicular damage in male mice. However, the mechanisms through which ZIKV enters the testes remain unclear. In this study, we revealed that matrix metalloproteinase 9 (MMP9) was upregulated by ZIKV infection in cell culture and in A129 mice. Furthermore, using an in vitro Sertoli cell barrier model and MMP9-/- mice, we found that ZIKV infection directly affected the permeability of the blood-testis barrier (BTB), and knockout or inhibition of MMP9 reduced the effects of ZIKV on the Sertoli cell BTB, highlighting its role in ZIKV-induced disruption of the BTB. Interestingly, the protein levels of MMP9 were elevated by ZIKV nonstructural protein 1 (NS1) in primary mouse Sertoli cells (mSCs) and other cell lines. Moreover, the interaction between NS1 and MMP9 induced the K63-linked polyubiquitination of MMP9, which enhanced the stability of MMP9. The upregulated MMP9 level led to the degradation of essential proteins involved in the maintenance of the BTB, such as tight junction proteins (TJPs) and type Ⅳ collagens. Collectively, we concluded that ZIKV infection promoted the expression of MMP9 which was further stabilized by NS1 induced K63-linked polyubiquitination to affect the TJPs/ type Ⅳ collagen network, thereby disrupting the BTB and facilitating ZIKV entry into the testes.

Gaze Point in the Evacuation Drills: Analysis of Eye Movement at the Indoor Wayfinding

Signage systems are the main means of resolving the wayfinding problem in an emergency evacuation. However, recent literature has proven that signage systems are often not effective in an indoor wayfinding decision-making situation. Many studies that attempted to solve the problem did not consider the interaction between the optimal location of signage systems and gaze characteristics. Therefore, this study aimed to provide basic database to determine the optimal location of signage by analysing the characteristics of eye movements according to the type of junction. To achieve this, we conducted evacuation experiments in a maze set composed of eight junctions that we created ourselves and analysed the eye movement data of participants with 5196 gaze points and duration of 895,581.49 ms. The result showed that participants most often look between 100 cm and 150 cm (vertical height) in the corridor and in junctions. In addition, the gaze points of the evacuees are quantified by the horizontal and vertical directions according to the type of junction where the wayfinding decisions occur. This investigation showed that there are marked differences depending on the type.

Using Deep Learning to Identify Molecular Junction Characteristics.

The scanning tunneling microscope-based break junction (STM-BJ) is used widely to create and characterize single metal-molecule-metal junctions. In this technique, conductance is continuously recorded as a metal point contact is broken in a solution of molecules. Conductance plateaus are seen when stable molecular junctions are formed. Typically, thousands of junctions are created and measured, yielding thousands of distinct conductance versus extension traces. However, such traces are rarely analyzed individually to recognize the types of junctions formed. Here, we present a deep learning-based method to identify molecular junctions and show that it performs better than several commonly used and recently reported techniques. We demonstrate molecular junction identification from mixed solution measurements with accuracies as high as 97%. We also apply this model to an in situ electric field-driven isomerization reaction of a [3]cumulene to follow the reaction over time. Furthermore, we demonstrate that our model can remain accurate even when a key parameter, the average junction conductance, is eliminated from the analysis, showing that our model goes beyond conventional analysis in existing methods.

Investigating the electronic properties of shrimp synthetic viral DNAs integrated within Schottky junctions

In this report, DNA-specific Schottky junctions were used for studying electronic properties of selected viral-derived DNAs. Two junction types were studied in this work; Al//DNA/ITO/Al and Cu/DNA/Cu using synthetic sequences of viral infecting shrimps commonly found in aquaculture. Two models based on thermionic emission theory were employed to calculate selected solid-state parameters. The ideality factor for example calculated using Cheung’s method for all viral DNA samples showed values between 11.27 to 17.56 and 8.35 to 8.67 when using the Al/DNA/ITO/Al and Cu/DNA/Cu junctions, respectively. In general, characteristic profiles and parameters were observed for all DNA sequences studied using both junctions.