Transverse Branch Research Articles

Remarkable thermoelectric performance in BaPdS2 via pudding-mold band structure, band convergence, and ultralow lattice thermal conductivity

Efficient thermoelectric materials require a rare and contraindicated combination of materials properties: large electrical conductivity, large Seebeck coefficient, and low thermal conductivity. One strategy to achieve the first two properties is via low-energy electronic bands containing both flat and dispersive parts in different regions of crystal momentum space, known as a pudding-mold band structure. Here, we illustrate that ${\mathrm{BaPdS}}_{2}$ successfully achieves the pudding-mold band structure for the valence band, contributing to a large $p$-type thermoelectric power factor, due to its anisotropic crystal structure containing zigzag chains of edge-sharing square planar ${\mathrm{PdS}}_{4}$ units; large power factor is achieved for $n$-type doping as well due to band convergence. In addition, ${\mathrm{BaPdS}}_{2}$ exhibits ultralow lattice thermal conductivity, and thus also achieves the third property, due to extremely soft and anharmonic interactions in its transverse acoustic phonon branch. We predict a remarkably large thermoelectric figure of merit, with peak values between 2 and 3 for two of the three crystallographic directions, suggesting ${\mathrm{BaPdS}}_{2}$ warrants experimental investigation.

Atomistic structure and collective dynamics in liquid Pb along the melting line up to 70 GPa: A first-principles molecular dynamics study

Ab initio molecular dynamics simulations were performed to analyze changes in the structure and dynamics of molten Pb along the melting line for pressures ranging from ambient to 70 GPa. Common neighbor analysis reveals a local structural order of the underlying crystalline phase at the corresponding pressure, which increasingly competes with the existing icosahedral local order with pressure. Obtained dispersions of longitudinal and transverse collective excitations contain two branches of transverse modes for all pressures. Analysis of the pressure dependence of observed two-peak structure of the Fourier spectra of velocity autocorrelation functions allowed us to identify their peak locations with the frequencies of nonpropagating transverse branches in the second pseudo-Brillouin zone.

Evaluation of Donor Morbidity following Single-Stage Latissimus Dorsi Neuromuscular Transfer for Facial Reanimation

Single-stage latissimus dorsi neuromuscular transfer has been a valuable option for dynamic smile reanimation. However, there is a paucity of studies evaluating the potential donor morbidity in such cases. The present study aimed to comprehensively analyze the donor morbidity following functional latissimus dorsi muscle transfer. Patients who underwent single-stage functional latissimus dorsi muscle transfer for smile reanimation between 2002 and 2016 were reviewed. Postoperative complications and functional impairments at the donor sites were evaluated. The Quick-Disabilities of the Arm, Shoulder and Hand questionnaire was used for assessing postoperative donor-site function. Sixty patients, including 12 pediatric (18 years or younger) patients, were analyzed. Mean length of a harvested thoracodorsal nerve was 14.9 cm. Fourteen patients were treated with a dual innervation technique, in which both a descending and a transverse branch of the thoracodorsal nerve were harvested. Donor complications were observed in seven cases; all of them were seromas and resolved by simple aspiration. No other complications including scoliosis and sensory and/or motor disturbances in the upper extremities were encountered. Fifty patients responded to the Quick-Disabilities of the Arm, Shoulder and Hand questionnaire at a median follow-up of 51 months. The average score was 2.64, and all but three patients scored less than 10. No variables, including patient age (pediatric versus adult) and the use of a dual-innervation technique, affected the donor morbidities, including the functional deficits. Single-stage latissimus dorsi neuromuscular transfer for facial reanimation might be associated with a low rate of complications and minimal functional morbidity at the donor site. Therapeutic, IV.

An axial semi-rigid connection model for cross-type transverse branch plate-to-CHS joints

This study is aimed to develop a model to accurately predict the semi-rigid performance of branch plate-to-circular hollow section (CHS) joints for tubular structures. First of all, a finite element (FE) model for cross-type transverse branch plate-to-CHS (CTTPCHS) joints is calibrated by test results. Based on the improved Menegotto-Pinto equation and the axial load-local deformation curves that are resulted from the calibrated FE model, an axial semi-rigid connection model for CTTPCHS joints is established, which has 7 parameters including the axial initial stiffness. Then, the method to obtain 7 parameters is determined, and a theoretical formula for axial initial stiffness of the joints is established based on the quarter-circular arch model. The complex expression of the formula is simplified to the product of an exponential function and a power function. In addition, a numerical parametric study on 7 parameters is carried out by the calibrated FE model. And based on the results of parametric analysis and multivariate nonlinear regression analysis, the parametric formulas for the 7 parameters are established. Finally, a comparison between the FE analysis results and the semi-rigid connection model calculation results from the parametric formulas is made, which shows the axial semi-rigid connection model a good reliability.

Failing to harvest two-paddle anterolateral thigh flap and converting algorithm

Objective To explore how to overcome the difficulties during two paddle anterolateral thigh flap harvest. Methods From January, 2009 to December, 2015, the harvest of two paddle anterolateral thigh flap was encountered difficulties during surgery in 8 cases, which were 7 males and 1 female. The age was ranged from 16 to 48 years old, with averaged of 32.8. Six patients presented with one defect, and 2 patients presented with two defects. The skin defects ranged from 60-247 cm2. The number of the flap perforator, vascular source, flap pattern and outcomes was recorded. All patiants were followed-up at regular intervals. Results All of 8 flaps were converted successfully during surgery. Only 1 perforator was found in 4 cases. The flap was converted to sigle perforator flap. The dornor site was covered by skin graft. Two perforators from different origins were found in 2 cases, and the flap was converted to sequential chimeric flap. Two perforators from descending branch and transverse branch respectively were found in 1 case, and the flap was converted to combined anterolateral thigh and tensor fascia lata flap. Only 1 perforator was found in 1 case, which the distal defect was small sized, the flap was converted to deepithelialized two paddle flap. The flap ranged from 78-288 cm2. Venous compromise was happened in 1 case, and the flap survived after reexploration surgery. Local infection was found in 2 cases, and cured with wound dressing. Other flaps were survived uneventfully. At donor site, 1 case wound dehiscence and 1 case local infection, both of which underwent debridement and healed. All patiants were followed-up for 7-21(mean, 11.5)months. The flaps had satisfactory appearance and soft texture. Conclusion When it is difficult to harvest two paddle anterolateral thigh flap during surgery, the flap need to be converted rationally based on the characteristics of the defect, the number of the flap perforator, and the vascular origins. Key words: Two paddle flap, perforator flap; Anterolateral thigh flap; Limb; Transplantation; Microsurgical technique

Lanlabeo duanensis, a new genus and species of labeonin fish (Teleostei: Cyprinidae) from southern China.

Lanlabeo, a new genus of fish belonging to the family Cyprinidae, is described from the Pearl River drainage basin in Guangxi Province, southern China. This new genus is distinguished from all other genera of the cyprinid tribe Labeonini by a combination of morphological and phylogenetic characters. It differs morphologically from all other Asian labeonins in its uniquely modified oromandibular morphology. For example, this genus has a frenum connecting the upper jaw and lower lip at the corner of the mouth, regularly arranged papillae densely scattered over the ventral margin of the rostral cap, a vestigial upper lip, a rostral cap overlying the upper jaw and with a fimbriate posterior margin, and a lower lip divided into two lateral fleshy lobes and one central plate. These two lateral fleshy lobes are small and translucent, and the median lobe of the lower lip is large and has papillae regularly arranged in many transverse rows. In the lower jaw, the dentary is transversely L-shaped in ventral view because its anterior part forms a right-angle turn and its transverse branch is anterioposteriorly expanded. In addition, analyses of four nuclear gene datasets indicate that this new genus forms a highly divergent lineage within the Labeonini, and that Lanlabeo is closely related to the genus Ptychidio. Therefore, based on morphometric differences and phylogenetic relationships, we describe this new genus herein as Lanlabeo, containing the new species Lanlabeo duanensis.

Characteristics of Output Filters Providing Electromagnetic Compatibility of the Frequency Converter of an Electric Drive with Asynchronous Motors

An analysis of the characteristics of the output filters of electromagnetic compatibility of a frequency converter, including their logarithmic amplitude-frequency characteristics, is carried out by mathematical modeling. The filters with the different parameters, are considered in the steady operation mode at the carrier frequency of pulse-duration modulation of 2.5 kHz and basic frequency of supply voltage of the asynchronous motor of 50 Hz, including with the different connection diagrams of the damping resistors—with parallel connection of inductance in the longitudinal filter branch and series connection of the capacity in the transverse filter branch. In addition, the filter is studied, not including the damping resistors. The losses in the filters are considered. A conclusion is drawn that it is necessary to consider the parasitic parameters of the capacitors: equivalent series inductance, equivalent series resistance, equivalent parallel resistance considering the leakage current through the capacitor, and voltage regulator diode simulating the behavior of the capacitor under the overvoltages.

Minimizing Cost Travel in Multimodal Transport Using Advanced Relation Transitive Closure

The optimization computation is an essential transversal branch of operations research which is primordial in many technical fields: transport, finance, networks, energy, learning, etc. In fact, it aims to minimize the resource consumption and maximize the generated profits. This work provides a new method for cost optimization which can be applied either on path optimization for graphs or on binary constraint reduction for Constraint Satisfaction Problem (CSP). It is about the computing of the “transitive closure of a given binary relation with respect to a property.” Thus, this paper introduces the mathematical background for the transitive closure of binary relations. Then, it gives the algorithms for computing the closure of a binary relation according to another one. The elaborated algorithms are shown to be polynomial. Since this technique is of great interest, we show its applications in some important industrial fields.

Towards a better understanding of wormhole propagation in carbonate rocks: Linear vs. radial acid injection

Understanding acid reactive flow and the formation of wormholes in carbonate rocks is important for designing successful acidizing operations. Linear coreflooding experiments have been widely carried out to gain insights about the dissolution process for varying rock types and acid systems. However, carbonate reservoir stimulation is dictated by radial flow configuration. As such, it is critical to bridge the gap between linear acid injection and radial acid injection. In this work, a series of radial acid injection and linear acid flow experiments are conducted at various injection rates while maintaining the same operating conditions. The objective is to develop a better understanding of the acidizing process under radial flow conditions at larger scale while applying high confining stresses as only a limited number of radial flow experimental studies have been reported in the literature. This is expected to provide guidance for the optimization and control of the matrix acidizing process for the field operations. The radial acidizing tests are performed on rectangular block samples with dimensions of 20 × 16 × 16 in. We use a quantitative acidizing model to select few representative acid injection rates due to the complexity of the experiments and limited availability of large block samples. This model shows good predictive capability when compared to the experimental results. Pore volume to breakthrough (PVBT) and optimum injection rate are determined for both radial and linear acidizing experiments. Lower PVBT values are obtained for the radial acidizing case. This is mostly associated with the larger rock pore volume exposed to acid for the radial block in comparison to the linear cylindrical core. High-resolution CT scan images of the acidized radial carbonate blocks and cylindrical cores are generated and analyzed. The CT scan images show different wormhole morphology when varying the acid injection rates. Similar branching features are obtained for the optimal wormholes in linear and radial tests. Injecting the acid at the optimal rate leads to fewer transverse branches but thicker when compared to the experiment at higher injection rate that requires more acid volume to breakthrough. The low injection rate results in the largest diameter wormholes with high tortuosity. The high-resolution nondestructive imaging and analysis has enabled to gain insight on the interaction between the acid and the rock sample under radial flow conditions. This analysis has revealed that the wormhole propagation direction is not only governed by the effective stress differential but also can be aligned with the fabric layers due to the sedimentation conditions of the rock.

Anatomical Consideration for the Safe Elevation of the Deep Circumflex Iliac Artery in Flap Surgery.

Deep circumflex iliac artery osteocutaneous flap transfer has frequently been applied to large defects in the maxillary and mandible regions, but the use rate has decreased gradually because of the complicated anatomy of the deep circumflex iliac artery. This study investigated the comprehensive anatomy of the deep circumflex iliac artery in relation to flap surgery with the aim of providing navigational guidelines for safe deep circumflex iliac artery harvesting. Sixty-two sides of the hemi-abdominal wall were dissected in fixed Korean cadavers. Several dimensions of the deep circumflex iliac artery and its positional relationships with surgical landmarks were measured, and the patterns of the arterial supply and anastomosis were identified. The mean distance between the anterior superior iliac spine and the lateral border of the femoral artery was 57.5 mm. The deep circumflex iliac artery generally originated almost at the same level as the inguinal ligament, and its highest level was 14.8 mm superior to that ligament. Emerging points of the ascending branch were observed both medial and lateral to the anterior superior iliac spine, but no transverse branch pierced the transversus abdominis muscle medial to the anterior superior iliac spine. The incision line for safe deep circumflex iliac artery harvesting was parallel and 2 cm superior to the inguinal ligament and 6 cm from the anterior superior iliac spine. This position of the safe incision line can be easily determined using the thumb. Sex differences in the incidence of the deep circumflex iliac artery originating above or below the inguinal ligament will be another useful guide for easily detecting the deep circumflex iliac artery.

Design of Mini Latissimus Dorsi Flap Based on Thoracodorsal Vascular Patterns.

Latissimus dorsi (LD) flap has been used for reconstructive purposes in oncoplastic breast surgery. Using large part of the muscle as a flap leads to a residual functional loss. Muscle sparing and mini LD flaps can be used with no functional sequelae. However, the design of such flap presents a challenge. Twenty cadavers were dissected on both sides to identify the different vascular patterns of the thoracodorsal (TD) pedicle. The vessels were counted, and the following measurements were taken: diameter, length, distance from inferior angel of scapula, and vertebral level. Data were collected and entered into the personal computer. Statistical analysis was done using (SPSS/version 20) software. Five vascular patterns of TD pedicle were found. Type 1: a long vertically descending pedicle giving 3 to 4 transverse medial branches to LD in 40%. Type 2: a short pedicle terminating into 1 to 2 serratus anterior collaterals and 1 to 2 transverse lateral branches to LD in 10%. Type 3: a long vertically descending pedicle giving 2 to 3 small lateral branches to upper part of LD and terminating into medial and lateral branches in the lower part of LD in 10%. Type 4: a short pedicle that gives 4 to 5 terminal branches to LD, one of them is a long vertically descending branch to lower part of LD in 20%. Type 5: a short pedicle that terminates into a transverse medial and a long vertical branch to LD in 20%. The classically described pattern of TD pedicle (type 5) was found in 20% of cases, whereas the most commonly found pattern was type 1. This means that the pattern of TD branching is unpredictable, and a preoperative ultrasound is essential to define the existing pattern and plan the best LD flap design for each patient. In types 1 and 5, the flap can be designed using the transverse medial branch or branches. In type 2, one of the lateral transverse branches can be used. In types 3, 4, and 5, the long descending vertical branch can be used. It has a sizeable diameter (1.80.23 mm), length (12.31.64 cm), and can be located 6.50.96 cm below the inferior angle of scapula.

Arthroscopy of the distal radioulnar joint

The aim of the procedure is to visualize the proximal pouch of the DRUJ, the joint surfaces of the sigmoid notch and the ulnar head, the convexity of the ulnar head and the proximal ulnar side surface of the triangular fibrocartilage complex (TFCC). Arthroscopy of the distal radioulnar joint is applied for the evaluation of joint pathologies in ulnar-sided wrist pain, especially in cases without diagnostic findings in standard X‑rays and MRIs and arthroscopically assisted procedures. In vertical extension, two portals of the wrist are created on the dorsal side of the DRUJ between the extensor digiti minimi and extensor carpi ulnaris tendons. By insertion of asmall joint arthroscope via these portals visualization of the ulnar head, the sigmoid notch, the proximal pouch of the DRUJ and the proximal surface of the TFCC is accomplished. Arthroscopy of the DRUJ is ararely and not routinely performed procedure for the diagnosis and therapy of ulnar-sided wrist pain. It is technical demanding with aflat learning curve and anatomy-related obstacles. Acomplete view of the joint is not always accessible. Rare complications are injuries of the extensor digiti minimi tendon, as well as contusion or sectioning of the transverse branch of the dorsal branch of the ulnar nerve. In distinct cases, this procedure offers important additional information about the distal radioulnar joint. The procedure is especially valuable for the detection of proximal TFCC injuries that are missed otherwise.

Soft-phonon dynamics of the thermoelectric β-SnSe at high temperatures

Results of inelastic neutron scattering experiments on SnSe single crystals at high temperatures along with theoretical studies based on the density functional theory are reported. Our experiments reveal significant softening of the transverse acoustic branch along the [0,ξ,0] direction in the low-temperature α-SnSe of Pbnm symmetry as temperature approaches Tc=807 K from below. This process is followed by a condensation of the zone-boundary Y-phonon of the high-temperature β-SnSe with Cmcm symmetry at the onset of phase transition. The employed theoretical approach supports experimental observations and demonstrates that the phase change in SnSe is mediated by an unstable zone-boundary phonon with the Y2+ irreducible representation within the Cmcm symmetry space group of the high-temperature β-SnSe. The present work provides a detailed understanding of the soft-mode dynamics in SnSe and conclusively shows that the α⇌β structural transformation in this currently topical thermoelectric material is of displacive type.

Phonon dispersion evolution in uniaxially strained aluminum crystal

The influence of loading upon the phonon dispersion of crystalline materials could be highly nonlinear with certain particular trends that depend upon the loading path. In this paper, we have calculated the influence of [100] uniaxial strain on the phonon dispersion and group velocities in fcc aluminum using second moments of position obtained from molecular dynamics (MD) simulation at 300 K. In contrast to nonlinear monotonic variation of both longitudinal and transverse phonon frequencies along the $$\Delta $$ , $$\Lambda $$ and $$\Sigma $$ lines of the first Brillouin zone under tension, transverse phonon branches along the $$\Lambda $$ line show inflection at specific wavevectors when the compressive strain exceeds 5%. Further, the longitudinal group velocities along the high-symmetry $$\Delta $$ line vary non-monotonically with strain, reaching a minimum at 5% compressive strain. Throughout the strain range studied, the equilibrium positions of atoms displace in an affine manner preserving certain static structural symmetry. We attribute the anomalies in the phonon dispersion to the non-affine evolution of second moments of atomic position, and the associated plateauing of force constants under the applied strain path.

Distally based anterolateral thigh flap pedicled on the oblique branch of the lateral circumflex femoral artery

Background: A distally based anterolateral thigh (dALT) flap is an alternative option for reconstructing defects around the knee. This article presents our clinical experience with the use of the dALT flaps based on the oblique branch of the lateral circumflex femoral artery (LCFA) to reconstruct defects in the genicular and popliteal regions. Methods: Between 2008 and 2016, seven patients (4 males and 3 females, between 3–58 years old, mean =34 years) underwent reconstruction of defects around the knee using a dALT flap based on the LCFA oblique branch. Defect etiologies included malignant neoplasm (3 cases) and post-burn scar contracture (4 cases). Results: Reconstruction was successfully performed in all patients. The average flap size was 16.3 cm long (range, 9–24 cm) and 7.3 cm wide (range, 6–8 cm), while the mean pedicle length was 17.7 cm (range, 12–22 cm). The oblique branches originated from the LCFA descending branch in 6 patients and the transverse branch in one patient. One patient had a severely hypoplastic LCFA descending branch and thus the flap was based on the rectus femoris branch. In another patient, the pedicled dALT flap was converted to a free flap because the oblique branch originated from the transverse branch. All flaps survived without any major complications. Conclusions: Our experience demonstrated that we can reliably raise a dALT flap based on the oblique branch when it arises from the LCFA descending branch and sends cutaneous perforators to the anterolateral thigh region.

Pedicled Descending Branch Latissimus Dorsi Mini-flap for Repairing Partial Mastectomy Defect: A New Technique.

Volume loss is 1 of the major factors influencing cosmetic outcomes of breast after partial mastectomy (PM), especially for smaller breasts, and therefore, volume replacement is critical for optimizing the final aesthetic outcome. We present a novel technique of raising a pedicled descending branch latissimus dorsi (LD) mini-flap for reconstruction of PM defects via an axillary incision. After PM, the LD mini-flap is harvested through the existing axillary incision of the axillary dissection or the sentinel lymph node biopsy. The descending branches of thoracodorsal vessels and nerve are carefully identified and isolated. The transverse branches are protected to maintain muscle innervation and function. The LD muscle is then undermined posteriorly and inferiorly to create a submuscular pocket and a subcutaneous pocket between LD muscle and superficial fascia. Once the submuscular plane is created, the muscle is divided along the muscle fibers from the deep surface including a layer of fat above the muscle. Finally, the LD mini-flap is transferred to the breast defect. Given the limited length and mobility of the LD mini-flap, this approach is best utilized for lateral breast defects. However, for medial defects, the lateral breast tissue is rearranged to reconstruct the medial breast defect, and an LD mini-flap is then used to reconstruct the lateral breast donor site. This technique can therefore be employed to reconstruct all quadrants of the breast and can provide aesthetic outcomes without scars on the back, with minimal dysfunction of LD muscle.

A Search for Two Types of Transverse Excitations in Liquid Polyvalent Metals at Ambient Pressure: An Ab Initio Molecular Dynamics Study of Collective Excitations in Liquid Al, Tl, and Ni

Recent findings of pressure-induced emergence of unusual high-frequency contribution to transverse current spectral functions in several simple liquid metals at high pressures raised a question whether similar features can be observed in liquid metals at ambient conditions. We report here analysis of ab initio molecular dynamics-derived longitudinal (L) and transverse (T) current spectral functions and corresponding dispersions of collective excitations in liquid polyvalent metals Al, Tl, Ni. We have not found evidences of the second branch of high-frequency transverse modes in liquid Al and Ni, while in the case of liquid Tl they were clearly present in transverse dynamics. The vibrational density of states for liquid Tl has a pronounced high-frequency shoulder, which is located right in the frequency range of the second high-frequency transverse branch, while for liquid Al and Ni the vibrational density of states has only a weak indication of possible high-frequency shoulder. The origin of specific behavior of transverse excitations in liquid Tl is discussed.

Structural properties of barium stannate

BaSnO3 has attracted attention as a transparent conducting oxide with high room temperature carrier mobility. We report a series of measurements that were carried out to assess the structure of BaSnO3 over a variety of length scales. Measurements included single crystal neutron and x-ray diffraction, Rietveld and pair distribution analysis of neutron powder diffraction, Raman scattering, and high-pressure x-ray diffraction. Results from the various diffraction probes indicate that both the long-range and local structures are consistent with the cubic symmetry. The diffraction data under pressure was consistent with a robustly cubic phase up to 48.9 GPa, which is supported by density functional calculations. Additionally, transverse phonon velocities were determined from measured dispersion of the transverse acoustic phonon branches, the results of which are in good agreement with previous theoretical estimates and ultrasound measurements.

Propagation of Bessel-X pulses in a hybrid photonic crystal

We report the propagation of Bessel-X pulses in a two-dimensional hybrid photonic crystal, investigated by the finite-difference time-domain method, in which broadband super-collimation and the propagation of self-collimated ultrashort pulses were reported. We first show the propagation of Bessel-X pulses in two-dimensional free space, whose transverse branches diverge rapidly with propagation. We then show that Bessel-X pulses propagate with their transverse and longitudinal shapes almost unchanged in the hybrid photonic crystal.

Wide stopband millimeter/terahertz lowpass filter using improved split ring resonator

In this paper, an improved split-ring resonator (ISRR) cell is proposed to realize wide stopband and miniaturization. This cell comprises a transverse microstrip branch in middle and two gaps on both sides with tapped-line input and output. The transmission coefficient is derived for ISRR based on the distributed circuit theory and odd-even mode theory. Then the novel low-pass filter (LPF) is designed by cascading several ISRR cells in terahertz and millimeter. The ISRR LPF possesses great characteristics such as wide stopband, deep transmission zeros and small size. Finally, the proposed filter was processed and tested in millimeter. The measured results show that the proposed filter has low insertion loss from 0.5 to 0.7 dB in U-band and a stopband inhibition at 31.7 dB in 110 GHz.