Triangular Structure Research Articles

Self-reconfiguration of PARTS: A parallel reconfiguration algorithm based on surface flow

In this paper, we present a parallel reconfiguration algorithm for shape-shifting modular robots with a triangular structure. The reconfiguration planning is based on partitioning the robot’s surface into source and sink sections for modules, using the largest common topology as a reference. Reconfiguration is realized by a synchronous surface flow of modules guided by the prior determination of module sources and sinks. Individual reconfiguration steps are carried out by a multi-step optimization framework, ensuring that intermediate configurations required for topology changes are valid and collision-free. With a configuration containing n modules, the algorithm completes the reconfiguration in O(n) reconfiguration steps and allows for a distributed and asynchronous hardware implementation. We demonstrate the performance of the proposed algorithm on multiple example configurations and compare the results to other reconfiguration approaches.

New approaches to study of mismatched interfaces structure on low-index surfaces by molecular dynamics simulation

We used molecular dynamics simulations to study the structure of mismatched Al/Ni and Ag/Cu interfaces, considering low-index surfaces of the substrate. Embedded Atom Potentials are being employed to mimic atomic interactions between the different elements. The effect of the substrate orientation on the adlayer structure is investigated. The results showed that, on the (111) substrate, the adlayer presents a coincidence site lattice characterized by a rotation (labeled α) with respect to the substrate. This coincidence site lattice may contain dislocations and twin boundary that can be produced by the occurrence of a twin spirals (with opposite directions). To accommodate the adlayer deposition on the substrate, a slight shuffling of some atoms occurs in the substrate and leads to a rectangular structures producing a dislocation. Furthermore, on the (001) substrate, the accommodation of the triangular structure on the square lattice (substrate) is produced by a shift of some atomic rows producing a dislocation. But, the agglomeration of several square structures of 2d shape gives rise to a polycrystal delimited by a disclination forming grain boundaries and vacancies. However, the inward adsorption on the (110) substrate restricts the space of extension of adsorbed atoms, producing linear cracks. The relaxation of atoms adsorbed on these cracks change the linear shape of vacancies towards a staircase structure.

Effects of the triangular hollow tubes structure and carbon coating on the lithium storage performances of Co3O4/NiO microspheres

Co3O4/NiO@C (CNOT@C) microspheres were synthesized via a facile solvothermal method and annealing treatment under an argon atmosphere. A high initial reversible specific capacity of 1469.7 mA h g−1 of CNOT@C was attained due to its high specific surface area from its unique triangular hollow tube morphology. These triangular hollow tubes relieved volume expansion from repeated cycling processes, with CNOT@C attaining a high reversible specific capacity of 694.9 mA h g−1 after 1000 cycles at 6000 mA g−1. Furthermore, excellent rate performance of CNOT@C was achieved due to its carbon layer coating, exhibiting a reversible specific capacity of 429.8 mA h g−1 at 10 000 mA g−1.

Lie super-bialgebra structures on the two dimensional supersymmetric Galilean conformal algebra

Let be the two dimensional supersymmetric Galilean conformal algebra. In this paper, we obtain that Lie superalgebra admits only triangular coboundary Lie super-bialgebra structures and the proof is mainly based on the computation of the first cohomology group of with coefficients in the tensor product of its adjoint module.

Application of Gob-Side Entry Driving in Fully Mechanized Caving Mining: A Review of Theory and Technology

China has abundant coal resources, and the distribution of coal seams is complex. Thick coal seams account for more than 45% of all coal seams. Fully mechanized top coal caving mining has the advantages of large production, high efficiency, and low cost. In fully mechanized caving mining, especially in fully mechanized caving mining of extra-thick coal seams, the mining space is ample, the mine pressure is severe, and the roadway maintenance is complex. As a result, it is necessary to summarize and discuss the gob-side entry driving of fully mechanized caving in theory and technology, which will help to promote the further development of fully mechanized caving gob-side entry driving technology. First, in recent years, the research hotspots of gob-side entry driving have focused on the deformation mechanism and the control method of the roadway surrounding rock. Secondly, this paper discusses the theoretical models of the “triangle-block” and “beam” for the activity law of the overlying strata in gob-side entry driving, including the lateral breaking “large structure” model, compound key triangle block structure model in the middle and low position, the high and low right angle key block stability mechanics model, elastic foundation beam model, low-level combined cantilever beam + high-level multilayer masonry beam structure model, and the vertical triangular slip zone structure model. It introduces the “internal and external stress field theory” and the “stress limit equilibrium zone model”. Thirdly, it summarizes several numerical simulation analysis methods in different conditions or research focuses and selects appropriate constitutive models and simulation software. Finally, it introduces surrounding rock control technology, including two ribs, the roof, and under challenging conditions. It provides a method reference for support in similar projects.

Utilizing photonic band gap in triangular silicon carbide structures for efficient quantum nanophotonic hardware

Silicon carbide is among the leading quantum information material platforms due to the long spin coherence and single-photon emitting properties of its color center defects. Applications of silicon carbide in quantum networking, computing, and sensing rely on the efficient collection of color center emission into a single optical mode. Recent hardware development in this platform has focused on angle-etching processes that preserve emitter properties and produce triangularly shaped devices. However, little is known about the light propagation in this geometry. We explore the formation of photonic band gap in structures with a triangular cross-section, which can be used as a guiding principle in developing efficient quantum nanophotonic hardware in silicon carbide. Furthermore, we propose applications in three areas: the TE-pass filter, the TM-pass filter, and the highly reflective photonic crystal mirror, which can be utilized for efficient collection and propagating mode selection of light emission.

Combining pMINFLUX, graphene energy transfer and DNA-PAINT for nanometer precise 3D super-resolution microscopy

3D super-resolution microscopy with nanometric resolution is a key to fully complement ultrastructural techniques with fluorescence imaging. Here, we achieve 3D super-resolution by combining the 2D localization of pMINFLUX with the axial information of graphene energy transfer (GET) and the single-molecule switching by DNA-PAINT. We demonstrate <2 nm localization precision in all 3 dimension with axial precision reaching below 0.3 nm. In 3D DNA-PAINT measurements, structural features, i.e., individual docking strands at distances of 3 nm, are directly resolved on DNA origami structures. pMINFLUX and GET represent a particular synergetic combination for super-resolution imaging near the surface such as for cell adhesion and membrane complexes as the information of each photon is used for both 2D and axial localization information. Furthermore, we introduce local PAINT (L-PAINT), in which DNA-PAINT imager strands are equipped with an additional binding sequence for local upconcentration improving signal-to-background ratio and imaging speed of local clusters. L-PAINT is demonstrated by imaging a triangular structure with 6 nm side lengths within seconds.

Preparation, characterisation, and in vitro cancer‐suppression function of RNA nanoparticles carrying miR‐301b‐3p Inhibitor

Multidrug resistance is the biggest barrier on the way to chemotherapy for lung adenocarcinoma (LUAD). For some LUAD patients with cisplatin (DDP) resistance and poor prognoses, the authors put forward RNA nanoparticles (NPs) carrying miR-301b-3p Inhibitor. The NPs were composed of miR-301b-3p, A549 aptamer (A549apt), and Cyanine 5 in a bottom-up manner with a 3-way-junction (3WJ) structure. Diameter, assembly process, and morphology of NPs were observed by Dynamic Light Scattering, Native-Polyacrylamide Gel Electrophoresis, and Atomic Force Microscopy. Cell internalisation, toxicity, proliferation, migration, invasion, and apoptosis were assayed by confocal laser scanning microscope, CCK8, colony formation assay, Transwell, western blot, and flow cytometry. 3WJ-apt-miR was evenly distributed, with diameter of 19.61±0.49nm and triangular branching structures. The accurate delivery of this NP in vivo was ensured by A549 aptamer featuring specific targeting, with smaller side effects than traditional chemotherapy. Such nanomaterials were effectively internalized by cancer cells, with normal cell activity intact. Cancer cell proliferation, invasion, and migration were suppressed, and DDP sensitivity was enhanced, causing DNA damage and facilitating apoptosis of DDP-resistant cells. Based on RNA self-assembling, the authors researched the effect of miRNA on DDP sensitivity in LUAD regarding gene regulation. 3WJ-apt-miR paves the way for clinical tumour therapy.

Self-Assembly of Two Tubular Metalloligand-Based Palladium-Organic Cages as Hosts for Polycyclic Aromatic Hydrocarbons.

Herein we report two tubular metal-organic cages (MOCs), synthesized by the self-assembly of bidentate metalloligands with different lengths and PdII. These two MOCs feature Pd4L8-type square tubular and Pd3L6-type triangular cage structures, respectively. Both MOCs have been fully characterized by NMR spectroscopy, mass spectrometry, and theoretical calculation. Both cages can be employed for encapsulating polycyclic aromatic hydrocarbons and show high binding affinity toward coronene.

Dermoscopic features of children scabies.

Scabies is a common skin disorder, caused by the ectoparasite Sarcoptes scabiei. The scabies mites burrow is highly diagnostic but illegible by the naked eye, because it is tiny and may completely be obscured by scratch and crust. The classic technique is opening the end of an intact mite burrow with a sharp instrument and inspecting its contents in the light microscope under loupe vision. Dermatoscope is a new method to diagnose scabies, with the advantages of non-invasive and more sensitive. This study verified the characteristic manifestations of scabies under dermoscopy. Under the closer examination of the curvilinear scaly burrow, the scabies mite itself may be seen as a dark equilateral triangular structure, which is often referred to as a "jet with contrail." Besides, this study found that the positive detection rate of microscopic characteristic manifestations under the dermoscopy ordered by the external genitals, the finger seams and the trunk, which were statistically different (P-value < 0.05). Of note, this is the first study to explore the regional distribution of the characteristic dermoscopic manifestations of scabies. We are the first to propose to focus on examining the external genitalia and finger seams with dermoscopy.

Frequency reconfigurable antenna actuated by inflated triangular structure: Design and analysis

This paper proposes a frequency reconfigurable triangular antenna actuated by an inflated triangular structure. The open path antenna is transformed from an open type to a closed structure by inflating. Inflatable structures are easy to manufacture by fusing 2 inextensible membranes together along a defined pattern of lines. However, the prediction of their deployed shape remains a challenge. To solve the pattern changed problem, guided by geometric analyses and local buckle characteristics, the inflated triangular structure has been designed and verified by experiment and simulation. In the process of transformation of the antenna, the resonant frequency of the antenna is changed because this frequency is determined by the conformational change. The resonant frequency changes from GHz to kHz when the design of initial structure sizes is from millimeter to meter. The measured peak gains, the frequency, and the radiation direction are also reconfigurable by the initial size. Finally, the reconfigurable resonator array is presented, which is coupled to electric fields to absorb all incident radiation. In this work, the changed pattern design by inflating is applied to the antenna design, and its frequency reconfigurability is achieved. Through the electricity performance analysis of the reconfigurable antenna, precise manufacturing will be possible and provide guidance for manufacturing frequency reconfigurable antennas.

Non-homogeneous Poisson process intensity modeling and estimation using measure transport

Non-homogeneous Poisson processes are used in a wide range of scientific disciplines, ranging from the environmental sciences to the health sciences. Often, the central object of interest in a point process is the underlying intensity function. Here, we present a general model for the intensity function of a non-homogeneous Poisson process using measure transport. The model is built from a flexible bijective mapping that maps from the underlying intensity function of interest to a simpler reference intensity function. We enforce bijectivity by modeling the map as a composition of multiple bijective maps that have increasing triangular structure, and show that the model exhibits an important approximation property. Estimation of the flexible mapping is accomplished within an optimization framework, wherein computations are efficiently done using tools originally designed to facilitate deep learning, and a graphics processing unit. Point process simulation and uncertainty quantification are straightforward to do with the proposed model. We demonstrate the potential benefits of our proposed method over conventional approaches to intensity modeling through various simulation studies. We also illustrate the use of our model on a real data set containing the locations of seismic events near Fiji since 1964.

Zagreb connection topological descriptors and structural property of the triangular chain structures

Mathematical chemistry is concerned with the use of mathematics to solve the problems in chemistry. A triangular chain graph is a simple graph composed of a series of triangles. This chain is widely used in the formation of triangular cactus, boron clusters, boron triangular nanotubes, and boron nanotubes. In this paper, the first Zagreb connection index, the first modified Zagreb connection index, and the second Zagreb connection index for triangular chain structures are calculated and derived closed formulas for them. Based on the derived formulas and obtained numerical results, the physicochemical properties of these type of structures can easily be investigated.

Surface characterization of CaF2 crystals irradiated with MeV ions below charge state equilibrium

Single crystals of CaF2, cleaved along the (111) plane, were irradiated by 35Cl, 39K, 52Cr, 58Ni, 79Br and 197Au ions with energies from 2 to 48 MeV, charge states from 1+ to 11+ and ion fluences from 2 × 1010 to 1 × 1013 ions/cm2. The surface properties of the irradiated samples were studied using Atomic Force Microscopy in contact mode. Nanoscale surface structures were observed for some surfaces irradiated by Cl, K, Cr, Ni, Br and Au ions. Thresholds for nanostructure formation were found in terms of projectile ion velocity and electronic stopping power (Se). Clear surface modification was observed for projectiles with specific energies above approximately 0.04 MeV/u. The threshold in Se for the generation of distinct triangular structures was observed to be velocity-dependent. The average formation efficiency, referring to the ratio of the number of distinct nanostructures observed on the surface to the number of incident ions, as well as the average height of nanostructures increases with Se.

Distributed and Scalable Cooperative Formation of Unmanned Ground Vehicles Using Deep Reinforcement Learning

Cooperative formation control of unmanned ground vehicles (UGVs) has become one of the important research hotspots in the application of UGV and attracted more and more attention in the military and civil fields. Compared with traditional formation control algorithms, reinforcement-learning-based algorithms can provide a new solution with a lower complexity for real-time formation control by equipping UGVs with artificial intelligence. Therefore, in this paper, a distributed deep-reinforcement-learning-based cooperative formation control algorithm is proposed to solve the navigation, maintenance, and obstacle avoidance tasks of UGV formations. More importantly, the hierarchical triangular formation structure and the newly designed Markov decision process for UGV formations of leader and follower attributes make the control strategy learned by the algorithm reusable, so that the formation can arbitrarily increase the number of UGVs and realize a more flexible expansion. The effectiveness and scalability of the algorithm is verified by formation simulation experiments of different scales.

Entanglement transfer via chiral and continuous-time quantum walks on a triangular chain

We investigate the chiral quantum walk (CQW) as a mechanism for an entanglement transfer on a triangular chain structure. We specifically consider two-site spatially entangled cases in short-time and long-time regimes. Using the concurrence as an entanglement measure; fidelity, and the Bures distance as the measure of the quality of the state transfer, we evaluate the success of the entanglement transfer. We compare the entangled state transfer time and quality in CQW against a continuous-time quantum random walk. We also observe the effect of mixed states on the entanglement transfer quality.

SURGICAL TREATMENT OF AN ABNORMAL UPPER LABIAL FRENUM IN PEDIATRIC DENTISTRY

Introduction: The superior labial frenum corresponds to a thin and triangular anatomical structure that has its formation during the third month of intrauterine life, located from the tubercle of the upper lip to the alveolar process. Abnormal insertion of the roof-labial frenulum is usually indicated for surgical removal. If the surgical procedure is not performed, the frenum causes instability, the main problem being the diastema between the incisors, which many times cannot be treated only by orthodontics. The purpose of correction of the upper labial frenum consists of eliminating excess free tissue between the teeth, in addition to the purpose of improving aesthetics. Objective: To describe a case report of surgical treatment of the upper labial frenum performed on a pediatric patient at a Dental Specialties Center. Case report: Female patient, 11 years old, referred by the orthodontist with indication for surgical treatment of the upper labial frenum. On intraoral physical examination, the presence of persistent roof-labial frenum and diastema between the upper central incisors was observed. In view of the data obtained in the anamnesis and physical examination, we opted for the frenotomy technique with the repositioning of the brake. Intraoral antisepsis and facial antisepsis were performed, followed by terminal infiltrative anesthesia in the anterior superior alveolar nerves, bilaterally. Two oblique incisions were made close to the insertion of the roof-labial frenum and then the repositioning of the. Friction movements were performed between the incisors and simple stitches were used for suturing. After two weeks, the patient returned and the presence of tissue remnant was observed, which was removed using the same anesthetic technique and with the aid of Metzenbaum scissors, without the need for a new suture. Conclusion: Surgical treatments for labial frenum present excellent results and should be chosen according to the individual needs of each patient, always evaluating the risks, benefits and advantages and disadvantages.

Reconfigurable Nanopolygons Made of DNA Catenanes.

The development of new types of bonds and linkages that can reversibly tune the geometry and structural features of molecules is an elusive goal in chemistry. Herein, we report the use of catenated DNA structures as nanolinkages that can reversibly switch their angle and form different kinds of polygonal nanostructures. We designed a reconfigurable catenane that can self-assemble into a triangular or hexagonal structure upon addition of programmable DNA strands that function via toehold strand-displacement. The nanomechanical and structural features of these catenated nanojoints can be applied for the construction of dynamic systems such as molecular motors with switchable functionalities.

An Analysis of the Static and Dynamic Behavior of the Hydraulic Compensation System of a Multichannel Valve

Electro-hydraulic proportional valve is the core control valve in many hydraulic systems used in agricultural and engineering machinery. To address the problem related to the large throttling losses and poor stability typically associated with these valves, here, the beneficial effects of a triangular groove structure on the related hydraulic response are studied. A mathematical model of the pressure compensation system based on the power-bond graph method is introduced, and the AMESim software is used to simulate its response. The results show that the triangular groove structure increases the jet angle and effectively compensates for the hydrodynamic force. The steady-state differential pressure at the valve port of the new pressure compensation structure was 0.65 MPa. Furthermore, experimental results show that the pressure difference at the main valve port is 0.73 MPa, and that the response time is less than 0.2 s. It is concluded that the new compensation structure has good pressure compensation response characteristics.

Dermoscopy of Crusted Scabies: Revisiting the New and Old Signs.

Dear Editor, Scabies is a common ectoparasitosis in India caused by the eight-legged mite, Sarcoptes scabiei var. hominis. Crusted scabies occurs predominantly in immunosuppressed individuals and presents with diffuse hyperkeratotic scales, crusts, or even erythroderma. It is highly contagious because crusted scabies patient may harbor millions of mites on their body in contrast to 10–12 mites found in classical scabies.[1] It may often be misdiagnosed due to the absence of typical nocturnal pruritus and atypical clinical presentations. Dermoscopy is extremely useful in the diagnosis of this uncommon variant of the common parasitosis. We present a case of crusted scabies showing the classical and newly described dermoscopic signs. A 38-year-old female, case of mixed connective tissue disease, on treatment with daily prednisolone (10 mg) along with azathioprine 100 mg and admitted to the medical ward due to cirrhosis and ascites, presented with skin rash of 1 month duration. On clinical examination, generalized erythematous rash with scaly papules and crusting was seen along with multiple dry crusted hyperkeratotic plaques (showing wet sand appearance) predominantly over the bony prominences, trunk, limbs, and scalp [Figure 1].Figure 1: (a) multiple dry crusted hyperkeratotic plaques with erythematous scaly papules and crusting. (b) scaly crusted plaque involving the scalp. (c) “wet sandpaper” appearance of crusted plaquesDermoscopic examination showed numerous burrows in a “noodle-like pattern” with multiple brownish triangular structures (delta glider sign) [Figure 2a]. These burrows showed the “gray-edged line sign”, which is a gray-brownish line on the outer edges of the burrow (Figure 2b) and wake sign [Figure 3]. Potassium hydroxide (KOH) mount of scales revealed numerous scabies mites and eggs [Figure 4]. On histopathology, hyperkeratosis, parakeratosis, acanthosis, and scabies mites in the stratum corneum were seen [Figure 5]. The patient was advised topical application of 5% permethrin cream every third day for 2 weeks along with oral ivermectin 12 mg to be taken on day 1, 2, and 8.Figure 2: Dermoscopy showing (a) “noodle-like pattern” consisting of accumulation of several curvilinear burrows displaying the “gray-edged line sign” [blue arrowhead (in fig b also)]. (Heine delta NC1, polarized, 10×) (b) brown-colored triangular structure (yellow arrow) that simulates a delta glider trailed by the jet contrail (inset). (Dinolite Videodermoscope polarized non-contact 50x)Figure 3: Wake sign—the burrow (black lines) and the wake-shaped scale (dashed line) together presenting a Y-shaped lesion. (Higher magnification Dinolite Videodermoscope polarized non-contact 50×)Figure 4: Potassium hydroxide mount showing numerous mites (red arrows), eggs (blue arrowhead), and scybala (yellow circles)Figure 5: Multiple scabies mites (black arrow) in stratum corneum (H & E 10x)Burrows are the pathognomonic lesions of scabies; however, they are difficult to be seen on naked eyes, especially in brown skin and in patients with excoriations. Various eponymous dermoscopic signs of scabies include “Delta sign”/“hang glider sign”/“triangle sign” (brownish triangular structures in the shape of hang glider) corresponding to the head and anterior legs of the mite and “Jetliner with contrail sign” (where the mite body appears translucent and air-filled burrow resembles a jetliner with contrail).[2] “Noodle pattern” or “millipede-like structure” (showing numerous burrows) as seen in our case is a characteristic dermoscopy sign of crusted scabies.[3] “Gray-edged line sign” on dermoscopy is a recently described sign where the dark line is often seen on the outer wall of the curved burrow and is supposed to form mainly due to the melanin containing fecal material of the mite, which gets deposited on the outer wall by the tail end of the mite as it crosses the curved burrow.[4] “Wake sign” is described as a pattern of scale reminiscent of the “wake” left on the water surface by a moving object.[5] All the dermoscopic signs were seen in our case. Thus dermoscopy is an extremely useful, rapid, and noninvasive in vivo tool for the diagnosis of crusted scabies. This case is interesting as the dermoscopic signs of noodle pattern and gray-edged line sign have not been previously described in Indian patients. Declaration of patients consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.