Junction Points Research Articles

Engine exhaust manifold with thermoelectric generator unit

Thermal energy recovery systems are subject of intensive research activities in automotive engineering. They are becoming appealing because of the energy savings, low maintenance requirements and compact designs. Another element is the increase in working temperature ranges over the previous maximum of 400 °C. This was limiting the positioning of these devices to mid and rear locations of the exhaust systems. They also contained a specially designed cooling system for the cold side of the thermoelectric generator unit, which effectively preformed the requirements of the cold junction point (Seebeck effect) between the “P” and “N” semiconductors. Currently, thermoelectric generator manufacturers are producing devices that could operate at the temperatures over 850 °C which is opening up different research and application opportunities. This research report shows a continuation of previous research work carried out, to test 850 °C thermoelectric generator units, using the performance specifications and measurements conducted in our labs. We have extrapolated and predicted power output further. In the research, we covered the concept of placing high-temperature thermoelectric generator units directly into the exhaust port of the engine, just outside the cylinder head. Novel development solution is presented, where a new thermoelectric generator unit is designed to be adaptable to the profile of the exhaust port. Computational fluid dynamics analysis was conducted on a real-world engine and concept models, confirming consistent thermal heat transfer from the combustion chamber of the engine into the exhaust manifold thermoelectric generator unit assembly. Cooling of the device is achieved by direct coolant flow from the cylinder head. It could also be realized using an external cooling system.

Temperature monitoring for femtosecond laser welded interconnection of MWCNT regular structure on PET substrate

In this article, we determine the impact of laser parameters on the development of a flexible conductive transparent film in multi wall carbon nanotubes (MWCNTs) regular structures fabricated on the PET substrate. Both MWCNT and PET are the attractive material for flexible electronics and technological interest in Micro/Nano-manufacturing. Now day, femtosecond laser irradiation nanojoining with selected surface treatments is introduced as an interface enhancer between MWCNT and the PET. We investigated the femtosecond laser of fused PET. After laser irradiation heating, thermal effects modify the structures, and the properties of MWCNTs at the junction point. The network created by Laser irradiation requires extreme parameters: Laser energy irradiation, the effective laser radius, and preheating temperature. Theoretical calculations show us that 90 mW under laser spot radius of 1.5 mm and preheating temperature of 300 K can generate 433.0845 K as surface temperature enough to connect 1 µm in thick of MWCNTs without damage the PET substrate.

Single‐chain polymer nanoparticles via click crosslinking and effect of photoinduced radical combination on crosslink points

AbstractFolding of azide functionalized polymer chains was obtained via the copper‐catalyzed azide alkyne cycloaddition (CuAAC) methodology using a light‐responsive crosslinker as the ‘click’ component. Subsequently, crosslinked junction points were combined with a photoinduced radical combination strategy to achieve more compact nanoparticles. The resultant folding particles possess smaller particle sizes and higher glass transition temperature values compared to their linear analogues. Fourier transform IR spectroscopy, SEC, DSC, dynamic light scattering, 1H NMR and TEM techniques were used for characterization. © 2020 Society of Chemical Industry

The Junction Problem for Two Weakly Curved Inclusions in an Elastic Body

Under study are the boundary value problems that describe the equilibria of two-dimensional elastic bodies with thin weakly curved inclusions in the presence of delamination, which means that there is a crack between the inclusions and an elastic body. Some inequality-type nonlinear boundary conditions are imposed on the crack faces that exclude mutual penetration. This puts the problems into the class of those with unknown contact area. We assume that the inclusions have a contact point, find boundary conditions at the junction point, and justify passage to infinity with respect to the rigidity parameter of the thin inclusion. In particular, we obtain and analyze limit models.

Soft nanocomposites based on nanoclay particles and mixed wormlike micelles of surfactants

Stable viscoelastic suspensions of bentonite clay particles in semi-dilute solutions of wormlike micelles of mixed zwitterionic (oleyl amidopropyl dimethyl carboxybetaine) and anionic (sodium dodecyl sulfate) surfactants were elaborated. They represent a novel type of soft nanocomposite with tunable viscoelastic matrix. Structural studies revealed that the clay is dispersed in a dense network of entangled wormlike micelles in the form of 100-nm tactoids. Rheological investigations demonstrated that clay particles can induce an increase of viscosity by up to one order of magnitude. The effect of the clay becomes more pronounced with increasing content of anionic surfactant in the mixture with zwitterionic surfactant, when the micelles become branched. This behavior was explained by the stabilization of micelle-nanoclay junction points due to the screening of the repulsion between positively charged fragments of zwitterionic head groups by added anionic surfactant. As a result of stabilization, the lifetime of surfactant-nanoclay junctions becomes much larger than the breaking time of micelles. The elaborated systems are of interest for many industrial applications.

Visualization of the electrophysiologically defined junction between the superior vena cava and right atrium.

An electrical superior vena cava (SVC) isolation from the right atrium (RA) sometimes can be challenging. For a safe and efficient SVC isolation, we aimed to visualize the accurate position of the SVC-RA junction on a three-dimensional (3D) mapping system using the decremental conduction properties of the SVC-RA junction in patients with atrial fibrillation (AF). This study consisted of 15 consecutive AF patients (11 males, age 59 ± 10 years). A 3D mapping catheter was positioned in the SVC-RA junction region while delivering a single extra-stimulus from the right atrial appendage (RAA), to discriminate the RA and SVC potentials. The electrophysiological SVC-RA junction was defined as the most proximal points where the SVC potentials were recorded, which were tagged on the 3D mapping system around the SVC-RA junction, where radiofrequency energy applications were applied. Around the SVC-RA junction, 9 ± 2 points were tagged on the 3D mapping system. The highest and lowest SVC-RA junction points were located on the anterior wall and posterior wall, respectively. The difference in the level between the highest and lowest SVC-RA junction points was 16.2 ± 6.3 mm. A successful SVC isolation was obtained in all patients without any complications. The plane of the electrophysiologically defined SVC-RA junction was not perpendicular to the body axis, but slanted due to the anterior side being higher. Recognizing the precise location of the SVC-RA junction would contribute to a safe and efficacious SVC isolation.

A thirty-year Landsat study reveals changes to a river-lake junction ecosystem after implementation of the three Gorges dam

Ecosystems at the junctions of large lakes and rivers are a significant resource which are yet susceptible to changes in the various water bodies. One of the most crucial river-lake junction points in China is the junction of Poyang Lake and the Yangtze River (JPLYR), with the Three Gorges Dam (TGD) upstream. Based on remote sensing images of the dry season from 1987 to 2018, landcover change of JPLYR was obtained using the random forest classification method. Linear regression, principal component analysis (PCA), and classification and regression tree (CART) were used to determine relationships between 16 hydrological variables regarding magnitude, duration, timing, variation, and vegetation area throughout different operational stages of the TGD. Results showed that the operation of the TGD has anticipated and elongated the dry seasons, with a consequential shortening of the flood seasons that now occur later in the year. The peak water level was significantly reduced (p < 0.05), while the minimum water level remained unchanged throughout the study period. There was a 344% increase in vegetation coverage across the JPLYR from 1987 (0.677 km2) to 2018 (3.005 km2). The earlier beginning of dry season (BDS) was found to be most significant in affecting the increased vegetation area before and after the operation of TGD. The results provide an essential reference for assessing the potential influence of newly proposed dams in river-lake junctions and for optimizing future operations.

Global G3 continuity toolpath smoothing for a 5-DoF machining robot with parallel kinematics

• A global G 3 continuity toolpath smoothing method is proposed for 5-DoF parallel machining robots. • Splines are constructed for SLSGs and to guarantee the G 3 continuity between the fitted curves and the adjacent toolpaths. • Smoothing for test toolpaths is conducted to show the validity of the proposed method in motion smoothness. Toolpath smoothing is an important approach to improve robots’ operational stability and machining quality. Nowadays, the corner rounding smoothing and curve fitting smoothing algorithms are usually adopted to process the linear toolpath segments to improve its continuity. But the high order continuity between the fitted curve and its adjacent curves is difficult to be guaranteed. For parallel machining robots (PMRs), the tangential, curvature and curvature derivative discontinuities at the junction may lead to the self-excited vibration of mechanical structure, consequently the machining efficiency and quality are decreased. Under this consideration, a global G 3 continuity toolpath smoothing method for five degrees of freedom (5-DoF) PMRs is proposed. The linear segments toolpath generated by the Computer-Aided Manufacturing (CAM) system is first divided into long linear segments (LLSs) and short linear segments groups (SLSGs) through breakpoint searching. At the junction point, a B-spline transition curve is inserted to blend adjacent toolpaths. For the SLSG, the quintic B-spline is adopted to fit the discrete data points, constraint equations about the derivatives at the start and end points are established to achieve G 3 continuity with the adjacent transition curves. Based on the proposed method, the smoothing for two test toolpaths is carried out, and experiments on a 5-DoF PMR are conducted to show the validity of the method in motion smoothness.

Disruption of PCDH10 and TNRC18 Genes due to a Balanced Translocation

Balanced chromosomal rearrangements are usually associated with a normal phenotype, although in some individuals, phenotypic alterations are observed. In these patients, molecular characterization of the breakpoints can reveal the pathogenic mechanism, providing the annotation of disease-associated loci and a better genotype-phenotype correlation. In this study, we describe a patient with a balanced reciprocal translocation between 4q27 and 7p22 associated with neurodevelopmental delay. We performed cytogenetic evaluation, next-generation sequencing of microdissected derivative chromosomes, and Sanger sequencing of the junction points to define the translocation's breakpoints at base pair resolution. We found that the PCDH10 and TNRC18 genes were disrupted by the breakpoints at chromosomes 4 and 7, respectively, with the formation of chimeric genes at the junction points. Gene expression studies in the patient's peripheral blood showed reduced expression of TNRC18, a gene with unknown function and clinical significance. PCDH10 plays a role in the development of the nervous system and might be involved with the patient's neurodevelopmental delay. In this study, the full molecular characterization of the junction points was shown as an efficient tool for fine breakpoint mapping in balanced translocations in order to unmask gene disruptions and investigate the potential pathogenic role of the disrupted genes.

Direct visualization of a strain-induced dynamic stress network in a SEBS thermoplastic elastomer with in situ AFM nanomechanics

Thermoplastic elastomers (TPEs) may generate a residual strain after being stretched, which hinders their potential for use in high-performance materials. However, the mechanism of the residual strain formation has not been sufficiently elucidated thus far. Here, we used atomic force microscopy-based nanomechanical mapping to investigate a stretched TPE specimen consisting of poly(styrene-b-ethylene-co-butylene-b-styrene) with a content of 15 wt% styrene (SEBS-15). In the SEBS-15 polymer structure that maintained a strain of 0.5, hard-segmental (HS) amorphous domains aggregated by poly(styrene) segments deformed and became oriented parallel to the stretching direction, whereas soft-segmental rubbery domains aggregated by poly(ethylene-co-butylene) segments elongated, formed a stress network using the HS domains as junction points. Moreover, an in situ observation adopted for the stretched SEBS-15 revealed that HS domains therein underwent a relative displacement and partial separation that was influenced by the formed stress network, which was strongly related to the irreversible phenomena.

Data science in the design of public policies: dispelling the obscurity in matching policy demand and data offer

Data Science (DS) is expected to deliver value for public governance. In a number of studies, strong claims have been made about the potential of big data and data analytics and there are now several cases showing their application in areas such as service delivery and organizational administration. The role of DS in policy-making has, on the contrary, still been explored only marginally, but it is clear that there is the need for greater investigation because of its greater complexity and its distinctive inter-organizational boundaries. In this paper, we have investigated how DS can contribute to the policy definition process, endorsing a socio-technical perspective. This exploration has addressed the technical elements of DS - data and processes - as well as the social aspects surrounding the actors’ interaction within the definition process. Three action research cases are presented in the paper, lifting the veil of obscurity from how DS can support policy-making in practice. The findings highlight the importance of a new role, here defined as that of a translator, who can provide clarity and understanding of policy needs, assess whether data-driven results fit the legislative setting to be addressed, and become the junction point between data scientists and policy-makers. The three cases and their different achievements make it possible to draw attention to the enabling and inhibiting factors in the application of DS.

A New Bony Anatomical Landmark for Lateral Skull Base Surgery.

The aim of the study was to propose a new bony landmark, point O, which is the junction point of the temporosphenoid suture and the infratemporal ridge; this landmark may improve the identification and preservation of neurovascular structures when approaches are used to access the middle cranial fossa in lateral skull base tumor surgeries. Fifteen cadaveric heads were measured for anatomical analysis. Related surgical landmarks were studied using the Destroscope virtual reality system and during the dissection procedures, and the results were analyzed and compared. From the perspective of the middle skull base, the radial lines from point O to the interior point of the superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum are approximately equal in length, with an average length of 23.22 mm, and the above 5 points form a sector with an angle of 66.07° and an area of 310.71 mm. Identification of point O as a landmark for lateral skull base surgery when other landmarks are not recognizable optimizes patient safety and surgeon confidence during complicated operations. The interior points of the superior orbital fissure, foramen rotundum, foramen ovale, and foramen spinosum are distributed on the arc of a circle whose center is point O. The sector formed by the above 5 points is not only a crucial area for the communication of lesions between the middle skull base and the infratemporal fossa but also a safe avenue through which to remove skull base lesions.

Understanding the Pathognomonic Tumefactive Appearance of Neurolymphomatosis: A Unifying Theory of Neurolymphoma

The diagnosis of peripheral neurolymphomatosis (NL) is difficult and often delayed, because patients can have isolated, nonspecific nerve symptoms. Magnetic resonance imaging will usually show nonspecific findings of enlarged, contrast-enhancing nerves. We aimed to elucidate the mechanism behind an imaging finding we believe is pathognomonic of NL and likely of other hematologic diseases with peripheral nerve involvement. We reviewed the imaging studies of a previously reported cohort of patients, in addition to those from more recent patients, all with tumefactive NL, in which enlarged nerve bundles were surrounded by tumor. We reviewed the demographic data, clinical data (e.g., primary or secondary disease, biopsy-proven diagnosis), and imaging findings (e.g., tumefactive appearance, primary involved nerve, location of epicenter of tumefactive appearance, vascular involvement). All cases showed a maximum tumefactive appearance at branch or junction points, with a gradual decrease of this appearance moving proximally and distally from the epicenter in a "crescendo-decrescendo" pattern. We have described this as a phasic mechanism with 3 phases: malignant cells fill the intraneural space; extrude at a weak spot of the nerve, which often occurs at a branch or junction point; and then expand and fill the subparaneurial space, creating the grossly tumefactive appearance with proximal and distal spread. We have presented a novel, unifying theory explaining the pathognomonic tumefactive appearance of NL. Our theory offers the first rational explanation for the radiological appearance of NL with peripheral nerve involvement. We believe that with earlier recognition of NL on imaging studies, patients will be able to receive an earlier diagnosis and undergo earlier treatment.

Effective Mechanical Advantage About the Ankle Joint and the Effect of Achilles Tendon Curvature During Toe-Walking.

Aim: To study the causes of locomotor dysfunction, estimate muscle forces, or understand the influence of altered sarcomere and muscle properties and behaviours on whole body function, it is necessary to examine the leverage with which contractile forces operate. At the ankle joint, current methods to quantify this leverage for the plantarflexors do not account for curvature of the Achilles tendon, and so may not be appropriate when studying equinus gait. Thus, novel methodologies need to be developed and implemented to quantify the Achilles tendon moment arm length during locomotion.Methods: Plantarflexor internal moment arm length and effective mechanical advantage of 11 typically developed young adults were calculated throughout stance, while heel-toe walking and voluntarily toe-walking on an instrumented treadmill. Achilles tendon moment arm was defined in two-ways: (1) assuming a straight tendon, defined between the gastrocnemius medialis myotendinous junction and Achilles tendon insertion point, and (2) accounting for tendon curvature, by tracking the initial path of the Achilles tendon from the calcaneal insertion.Results: When accounting for tendon curvature, Achilles tendon moment arm length and plantarflexor effective mechanical advantage did not differ between walking conditions (p > 0.05). In contrast, when assuming a straight tendon, Achilles tendon moment arm length (p = 0.043) and plantarflexor effective mechanical advantage (p = 0.007) were significantly greater when voluntary toe-walking than heel-toe walking in late stance.Discussion: Assuming a straight Achilles tendon led to a greater Achilles tendon moment arm length and plantarflexor effective mechanical advantage during late stance, compared to accounting for tendon curvature. Consequently, plantarflexor muscle force would appear smaller when assuming a straight tendon. This could lead to erroneous interpretations of muscular function and fascicle force-length-velocity behaviour in vivo, and potentially inappropriate and ineffective clinical interventions for equinus gait.

Sugar particles and their role in crystallization kinetics and structural properties in fats used for nougat creme production

Palm oil-based fat crystal networks, such as nougat cremes, often show liquid oil separation during storage. To understand the relationship between oil separation and the underlying fat crystal network retaining trapped liquid oil, palm oil dispersions with different sucrose particle size distributions were generated. In particular, the interplay of particle dispersity, crystallization kinetics, and mechanical properties were studied. The effect of sucrose particles on crystallization kinetics and mechanical properties was compared to a modified lipid profile by adding either a tripalmitin-rich fraction (palm stearin) or hazelnut oil to palm oil. The particle addition increased the maximum rate constants from 0.272 min−1 to 0.310–0.317 min−1, whereas the effect of a modified lipid profile on crystallization kinetics was far more pronounced (0.472 min−1 for stearin addition in contrast to 0.084 min−1 in the case of hazelnut oil addition). However, sucrose was found to be a bound filler and fine particles, in particular, substantially increase structural properties by providing junction points when fats crystallize under quiescent conditions. Furthermore, the yield point (τ0) was increased from 559 to 828 Pa by the addition of 5% fine particles to palm oil equal to the addition of 20% stearin.

A flexible platform for controlled optical and electrical effects in tailored plasmonic break junctions

Abstract Mechanically controllable break junctions are one suitable approach to generate atomic point contacts and ultrasmall and controllable gaps between two metal contacts. For constant bias voltages, the tunneling current can be used as a ruler to evaluate the distance between the contacts in the sub-1-nm regime and with sub-Å precision. This ruler can be used to measure the distance between two plasmonic nanostructures located at the designated breaking point of the break junction. In this work, an experimental setup together with suitable nanofabricated break junctions is developed that enables us to perform simultaneous gap-dependent optical and electrical characterization of coupled plasmonic particles, more specifically bowtie antennas in the highly interesting gap range from few nanometers down to zero gap width. The plasmonic break junction experiment is performed in the focus of a confocal microscope. Confocal scanning images and current measurements are simultaneously recorded and exhibit an increased current when the laser is focused in the proximity of the junction. This setup offers a flexible platform for further correlated optoelectronic investigations of coupled antennas or junctions bridged by nanomaterials.

Bidirectional Return-Stroke Model for the Calculation of Lightning Electromagnetic Fields

This article focuses on the bidirectional return-stroke propagation phenomenon in the initiation process of lightning return stroke. Different from the conventional return-stroke model, the return-stroke current waves in the bidirectional return-stroke model are considered to propagate simultaneously in both the upward and downward directions at two different speeds from the junction point, where the downward and upward leaders connect with each other. The finite-difference time-domain (FDTD) method in the two-dimensional cylindrical coordinate is employed for the calculation. From the simulation results of the bidirectional return-stroke model, it can be found that compared with the conventional return-stroke model, initial peaks will appear at the rising edges both for the vertical electric field and azimuthal magnetic field at the certain conditions. The influences of characteristic parameters, including the height of junction point, the propagation velocities of downward return strokes, and the ground conductivity, on the computed results are analyzed. To accurately reproduce the radiated electromagnetic fields, the bidirectional propagation model should be taken into consideration.

Developing Homosexuality: Fritz Morgenthaler, Junction Points and Psychoanalytic Theory

The Swiss psychoanalyst Fritz Morgenthaler (1919–84) is well known in German-speaking psychoanalysis as an early exponent of Heinz Kohut's self psychology, as an ethnopsychoanalytic researcher and as an original thinker on the topics of dreams, psychoanalytic technique and especially on sexuality (perversions, heterosexuality, homosexuality). In 1980, he presented the first psychoanalytic conception of homosexuality in the German-speaking world that did not view homosexuality in terms of deviance or pathology. His theory of ‘junction points’ ( Weichenstellungen) postulates three decisive moments in the development of homosexuality: a prioritized cathexis of autoeroticism in narcissistic development, a Janus-facedness of homosexual desire as an outcome of the Oedipal complex and the coming out in puberty. According to Morgenthaler, this development can result in non-neurotic or neurotic homosexuality. Less known than the theory of junction points and to some degree even concealed by himself (his earlier texts appeared later on in corrected versions) are Morgenthaler's pre-1980 accounts of homosexuality which deserve to be called homophobic. Starting with a discussion of this early work, the article outlines Morgenthaler's theoretical development with special focus on his theory of junction points and how this theory was taken up in psychoanalytic theory.

Arkeolojik Verilere Göre Doğu Trakya Kuzey Yolu

Küçük Asya ile Avrupa arasında geçiş noktası konumundaki Doğu Trakya, her iki kıtadan gelen yolların geçiş ve birleşme yeri olmuştur. Kuzey Yolu, bölgeden geçen Via Egnatia ve Via Militaris ile birlikte üç ana yoldan biridir. Pontos Euksenos (Karadeniz)'in batısı veya kuzeyine ya da tam tersi buradan Küçük Asya'ya doğru yapılan seferlerde MÖ 6. yüzyıldan MS 19. yüzyıla kadar tüm kara orduların kullandığı güzergâh olmuştur. Buna karşın Kuzey Yolu'nun güzergâhı üzerindeki arkeolojik veriler diğer yollar kadar değerlendirilmemiştir. Bu makalede arazi çalışması sırasında tespit edilen ve incelenen başta Kurtdere Köprüsü olmak üzere köprü, yol kalıntısı ve mil taşı kullanılarak Kuzey Yolu'nun Doğu Trakya Bölgesi içindeki güzergâhı tespit edilmeye çalışılmıştır. Ayrıca Kuzey Yolu'nun güneyindeki Via Militaris ile kuzeyindeki Salmydessos kenti ile bağlantı sağlayan yollar arkeolojik verilere göre değerlendirilmiştir.

Mastoid notch as a landmark for localization of the transverse-sigmoid sinus junction

BackgroundThe top of the mastoid notch (TMN) is close to the transverse-sigmoid sinus junction. The spatial position relationship between the TMN and the key points (the anterosuperior and inferomedial points of the transverse-sigmoid sinus junction, ASTS and IMTS) can be used as a novel method to precisely locate the sinus junction during lateral skull base craniotomy.MethodsForty-three dried adult skull samples (21 from males and 22 from females) were included in the study. A rectangular coordinate system on the lateral surface of the skull was defined to assist the analysis. According to sex and skull side, the data were divided into 4 groups: male&left, male&right, female&left and female&right. The distances from the ASTS and IMTS to the TMN were evaluated on the X-axis and Y-axis, symbolized as ASTS&TMN_x, ASTS&TMN_y, IMTS&TMN_x and IMTS&TMN_y.ResultsAmong the four groups, there was no significant difference in ASTS&TMN_x (p = 0.05) and ASTS&TMN_y (p = 0.3059), but there were significant differences in IMTS&TMN_x (p < 0.001) and IMTS&TMN_y (p = 0.01), and multiple comparisons indicated that there were significant differences between male&left and female&left both in IMTS&TMN_x (p = 0.0006) and in IMTS&TMN_y (p = 0.0081). In general, the ASTS was located 1.92 mm anterior to the TMN on the X-axis and 27.01 mm superior to the TMN on the Y-axis. For the male skulls, the IMTS was located 3.60 mm posterior to the TMN on the X-axis and 14.40 mm superior to the TMN on the Y-axis; for the female skulls, the IMTS was located 7.84 mm posterior to the TMN on the X-axis and 19.70 mm superior to the TMN on the Y-axis.ConclusionsThe TMN is a useful landmark for accurately locating the ASTS and IMTS.