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Abstract We study the chiral limit of 2d QCD with a single quark flavor at finite N c using LCT. By modifying the LCT basis according to the quark mass in a manner motivated by ’t Hooft’s analysis, we are able to restore convergence for quark masses much smaller than the QCD strong coupling scale. For such small quark masses, the IR of the theory is expected to be well described by the Sine-Gordon model. We verify that LCT numerics are able to capture in detail the spectrum and correlation functions of the Sine-Gordon model. This opens up the possibility for studying deformations of various integrable CFTs using LCT by considering the chiral limit of QCD like theories.

Abstract Copper Zinc Tin Sulphide (CZTS) is a propitious semiconductor for active absorber material in thin-film solar cells (SCs). Here, SC architecture comprising FTO/ZnS/CZTS/variable HTLs/Au is discussed. Fluorine-doped tin oxide (FTO) and gold (Au) are used as front and back contacts, respectively. Zinc sulphide (ZnS) is used as an active electron transport layer (ETL), while different Cu-based materials (Cu2O, CuO, CuI, and CuSCN) are used as hole transport layers (HTL). A one-dimensional solar cell capacitance simulator (SCAPS-1D) is utilized to simulate the SC structure. Among different Cu-based HTLs, Cu2O is preferred as a potential candidate for high cell performance of CZTS-based SC. The effects of various layer parameters such as thickness, doping density, and carrier concentrations, electron affinity of HTL and absorber, respectively, are also discussed. After optimization of the device, variation of operating temperature and the effect of series and shunt resistance are also taken into consideration. The optimized results of thickness and acceptor concentration (NA) of absorber material are 1.5 µm and approx. 1.0 × 1019 cm−3, respectively. In addition, the function of HTL (with and without) in the designed SC structure is also studied. Capacitance–voltage (C–V) characteristics are also discussed to get an insight of built-in potential. We have achieved cell performances viz. efficiency = 31.86%, short circuit current density = 32.05 mA/cm2, open circuit voltage = 1.19 V, and fill factor = 83.37%.

Abstract We use Lightcone Conformal Truncation (LCT)—a version of Hamiltonian truncation — to study the nonperturbative, real-time dynamics of ϕ 4-theory in 2+1 dimensions. This theory has UV divergences that need to be regulated. We review how, in a Hamiltonian framework with a total energy cutoff, renormalization is necessarily state-dependent, and UV sensitivity cannot be canceled with standard local operator counter-terms. To overcome this problem, we present a prescription for constructing the appropriate state-dependent counterterms for (2+1)d ϕ 4-theory in lightcone quantization. We then use LCT with this counterterm prescription to study ϕ 4-theory, focusing on the ℤ2 symmetry-preserving phase. Specifically, we compute the spectrum as a function of the coupling and demonstrate the closing of the mass gap at a (scheme-dependent) critical coupling. We also compute Lorentz-invariant two-point functions, both at generic strong coupling and near the critical point, where we demonstrate IR universality and the vanishing of the trace of the stress tensor.

Abstract In this work we investigate the Brinkman volume penalization technique in the context of a high-order Discontinous Galerkin method to model moving wall boundaries for compressible fluid flow simulations. High-order approximations are especially of interest as they require few degrees of freedom to represent smooth solutions accurately. This reduced memory consumption is attractive on modern computing systems where the memory bandwidth is a limiting factor. Due to their low dissipation and dispersion they are also of particular interest for aeroacoustic problems. However, a major problem for the high-order discretization is the appropriate representation of wall geometries. In this work we look at the Brinkman penalization technique, which addresses this problem and allows the representation of geometries without modifying the computational mesh. The geometry is modelled as an artificial porous medium and embedded in the equations. As the mesh is independent of the geometry with this method, it is not only well suited for high-order discretizations but also for problems where the obstacles are moving. We look into the deployment of this strategy by briefly discussing the Brinkman penalization technique and its application in our solver and investigate its behavior in fundamental one-dimensional setups, such as shock reflection at a moving wall and the formation of a shock in front of a piston. This is followed by the application to setups with two and three dimensions, illustrating the method in the presence of curved surfaces.

Abstract We consider Lorentzian CFT Wightman functions in momentum space. In particular, we derive a set of reference formulas for computing two- and three-point functions, restricting our attention to three-point functions where the middle operator (corresponding to a Hamiltonian density) carries zero spatial momentum, but otherwise allowing operators to have arbitrary spin. A direct application of our formulas is the computation of Hamiltonian matrix elements within the framework of conformal truncation, a recently proposed method for numerically studying strongly-coupled QFTs in real time and infinite volume. Our momentum space formulas take the form of finite sums over 2 F 1 hypergeometric functions, allowing for efficient numerical evaluation. As a concrete application, we work out matrix elements for 3d ϕ 4-theory, thus providing the seed ingredients for future truncation studies.

Context: Coronary artery perforation is a rare but potentially catastrophic complication of percutaneous coronary intervention (PCI). It is infrequent complication of PCI. Aims: The objective of the study is to report the 7-year experience of coronary artery perforation with respect to incidence, clinical and angiographic characteristics, management and outcomes. Settings and Design: The study involved retrospective analysis of single centre 7 years of percutaneous coronary intervention data. Patients who had complication of coronary artery perforation during PCI were identified and included in the study. Subjects and Methods: Retrospective analysis of clinical, angiographic and procedural characteristics as well as management and outcome of coronary artery perforation was done. Statistical Analysis Used: The whole data were tabulated, variables were presented as mean and percentages and comparison was done within them. Results: A total of 37 cases of coronary artery perforation were identified from 4532 PCI performed. Most of the coronary artery perforation belonged to Ellis Type II and Type III (both n = 15) followed by Type III CS and Type I. Lesions belonged to AHC/AHA Type C in 31 cases. Most frequent mechanism of coronary artery perforation was related to the use of guidewire and balloon (both n = 17). The total of 8 cases presented with cardiac tamponade requiring pericardiocentesis. Eleven cases required emergency covered stent implantation. In two cases microcoil was used while one case required polyvinyl alcohol particles to seal the perforation site. There was no in-hospital mortality while 30-day mortality occurred in one patient. One case was referred for emergency surgery. Conclusions: Coronary artery perforation is rare but potentially fatal complication of percutaneous coronary intervention. Complication of coronary artery perforation can be managed effectively in the catheterization laboratory without the need of emergency of bailout surgery and in-hospital outcomes remain good in the majority of cases.

Abstract We study 1+1 dimensional ϕ 4 theory using the recently proposed method of conformal truncation. Starting in the UV CFT of free field theory, we construct a complete basis of states with definite conformal Casimir, C $$ \mathcal{C} $$ . We use these states to express the Hamiltonian of the full interacting theory in lightcone quantization. After truncating to states with C ≤ C max $$ \mathcal{C}\le {\mathcal{C}}_{\max } $$ , we numerically diagonalize the Hamiltonian at strong coupling and study the resulting IR dynamics. We compute non-perturbative spectral densities of several local operators, which are equivalent to real-time, infinite-volume correlation functions. These spectral densities, which include the Zamolodchikov C-function along the full RG flow, are calculable at any value of the coupling. Near criticality, our numerical results reproduce correlation functions in the 2D Ising model.

Purpose: To report a rare presentation of the pericentral pattern of hydroxychloroquine (HCQ) retinal toxicity in a Caucasian female. Observations: The patient presented with 20 years of exposure to HCQ, at a daily dose of 5.2mg/kg of actual body weight, and manifested a pericentral-only phenotype of HCQ toxicity, as demonstrated with detailed structural and functional testing. Conclusions and importance: Although rare, the pericentral pattern of HCQ toxicity may occur in Caucasian patients in the absence of paracentral changes.

We investigate the suitability of the Brinkman penalization method in the context of a high-order discontinuous Galerkin scheme to represent wall boundaries in compressible flow simulations. To evaluate the accuracy of the wall model in the numerical scheme, we use setups with symmetric reflections at the wall. High-order approximations are attractive as they require few degrees of freedom to represent smooth solutions. Low memory requirements are an essential property on modern computing systems with limited memory bandwidth and capability. The high-order discretization is especially useful to represent long traveling waves, due to their small dissipation and dispersion errors. An application where this is important is the direct simulation of aeroacoustic phenomena arising from the fluid motion around obstacles. A significant problem for high-order methods is the proper definition of wall boundary conditions. The description of surfaces needs to match the discretization scheme. One option to achieve a high-order boundary description is to deform elements at the boundary into curved elements. However, creating such curved elements is delicate and prone to numerical instabilities. Immersed boundaries offer an alternative that does not require a modification of the mesh. The Brinkman penalization is such a scheme that allows us to maintain cubical elements and thereby the utilization of efficient numerical algorithms exploiting symmetry properties of the multi-dimensional basis functions. We explain the Brinkman penalization method and its application in our open-source implementation of the discontinuous Galerkin scheme, Ateles. The core of this presentation is the investigation of various penalization parameters. While we investigate the fundamental properties with one-dimensional setups, a two-dimensional reflection of an acoustic pulse at a cylinder shows how the presented method can accurately represent curved walls and maintains the symmetry of the resulting wave patterns.

Context: Coronary artery perforation is a rare but potentially catastrophic complication of percutaneous coronary intervention (PCI). It is infrequent complication of PCI Aims: The objective of the study is to report the 7-year experience of coronary artery perforation with respect to incidence, clinical and angiographic characteristics, management and outcomes. Settings and Design: The study involved retrospective analysis of single centre 7 years of percutaneous coronary intervention data. Patients who had complication of coronary artery perforation during PCI were identified and included in the study. Subjects and Methods: Retrospective analysis of clinical, angiographic and procedural characteristics as well as management and outcome of coronary artery perforation was done. Statistical Analysis Used: The whole data were tabulated, variables were presented as mean and percentages and comparison was done within them. Results: A total of 37 cases of coronary artery perforation were identified from 4532 PCI performed. Most of the coronary artery perforation belonged to Ellis Type II and Type III (both n = 15) followed by Type III CS and Type I. Lesions belonged to AHC/AHA Type C in 31 cases. Most frequent mechanism of coronary artery perforation was related to the use of guidewire and balloon (both n = 17). The total of 8 cases presented with cardiac tamponade requiring pericardiocentesis. Eleven cases required emergency covered stent implantation. In two cases microcoil was used while one case required polyvinyl alcohol particles to seal the perforation site. There was no in-hospital mortality while 30-day mortality occurred in one patient. One case was referred for emergency surgery. Conclusions: Coronary artery perforation is rare but potentially fatal complication of percutaneous coronary intervention. Complication of coronary artery perforation can be managed effectively in the catheterization laboratory without the need of emergency of bailout surgery and in-hospital outcomes remain good in the majority of cases. [ABSTRACT FROM AUTHOR]

Objective: The objective of the study was to determine the sites of plaque accumulation and to compare the plaque accumulated with metal, ceramic and self-ligating orthodontic brackets in order to clarify which bracket type had a higher plaque retaining capacity. Materials and methods: The study was done on 30 subjects who were scheduled for fixed orthodontic treatment including extraction of four premolars. Mesh-backed edgewise metal brackets, ceramic and self-ligating brackets were bonded to the premolars to be extracted using composite (Transbond XT, 3M). Teeth were extracted at 1, 2 and 3 weeks after bracket bonding. Plaque attached to the buccal surfaces was stained using plaque disclosing agent. (Alpha plac). The teeth were then immersed in fixative containing 4% formaldehyde and 1% glutaraldehyde in phosphate buffer for 24 hours, followed by 0.1 M phosphate buffer for 12 hours. The specimens were then mounted on aluminum stubs and sputter coated with gold prior to SEM examination. Results: The results showed that increased retention of plaque in ceramic brackets ligated with elastomeric ring followed by metal and comparatively less in self-ligating brackets at the base of the brackets. Conclusion: This study highlights that higher retention of plaque in ceramic brackets ligated with elastomeric ring followed with metal brackets ligated with steel ligatures and comparatively less plaque retention in self-ligating brackets. Excess composite around the bracket base is the critical site of plaque accumulation associated with fixed appliances due to its rough surface texture. [ABSTRACT FROM AUTHOR]