Initiation of fluid-induced fracture in a thick-walled hollow permeable sphere

The initiation of fluid-induced fracture in formations of permeable geomaterials subjected to quasi-stationary flow processes (drained response) can be strongly affected by Biot's coefficient and the size of the formation. The aim of this paper is to analyse the influence of these parameters on the initial fracture process of a thick-walled hollow permeable sphere subjected to fluid injection in the hole. Assuming that fracture patterns are distributed uniformly during the hardening stage of the fracture initiation process, the coupled fluid-solid problem is described by a nonlinear ordinary differential equation, which is solved numerically by means of finite differences combined with shooting and Newton methods. The finite difference code has also been validated in the elastic range, i.e., before initiation of fracture, against an original closed-form analytical solution of the above differential equation. The results show that the nominal strength of the sphere increases with increasing Biot's coefficient and decreases with increasing size

A phase-field chemo-mechanical model for corrosion-induced cracking in reinforced concrete

We present a new mechanistic framework for corrosion-induced cracking in reinforced concrete that resolves the underlying chemo-mechanical processes. The framework combines, for the first time, (i) a model for reactive transport and precipitation of dissolved Fe2+ and Fe3+ ions in the concrete pore space, (ii) a precipitation eigenstrain model for the pressure caused by the accumulation of precipitates (rusts) under pore confinement conditions, (iii) a phase-field model calibrated for the quasi-brittle fracture behaviour of concrete, and (iv) a damage-dependent diffusivity tensor. Finite element model predictions show good agreement with experimental data from impressed current tests under natural-like corrosion current densities

Plans and Example Results for the 2nd AIAA Aeroelastic Prediction Workshop

This paper summarizes the plans for the second AIAA Aeroelastic Prediction Workshop. The workshop is designed to assess the state-of-the-art of computational methods for predicting unsteady flow fields and aeroelastic response. The goals are to provide an impartial forum to evaluate the effectiveness of existing computer codes and modeling techniques, and to identify computational and experimental areas needing additional research and development. This paper provides guidelines and instructions for participants including the computational aerodynamic model, the structural dynamic properties, the experimental comparison data and the expected output data from simulations. The Benchmark Supercritical Wing (BSCW) has been chosen as the configuration for this workshop. The analyses to be performed will include aeroelastic flutter solutions of the wing mounted on a pitch-and-plunge apparatus

A Synthesis of Hybrid RANS/LES CFD Results for F-16XL Aircraft Aerodynamics

A synthesis is presented of recent numerical predictions for the F-16XL aircraft flow fields and aerodynamics. The computational results were all performed with hybrid RANS/LES formulations, with an emphasis on unsteady flows and subsequent aerodynamics, and results from five computational methods are included. The work was focused on one particular low-speed, high angle-of-attack flight test condition, and comparisons against flight-test data are included. This work represents the third coordinated effort using the F-16XL aircraft, and a unique flight-test data set, to advance our knowledge of slender airframe aerodynamics as well as our capability for predicting these aerodynamics with advanced CFD formulations. The prior efforts were identified as Cranked Arrow Wing Aerodynamics Project International, with the acronyms CAWAPI and CAWAPI-2. All information in this paper is in the public domain

Synthesis of Hybrid Computational Fluid Dynamics Results for F-16XL Aircraft Aerodynamics

A synthesis is presented of recent numerical predictions for the F-16XL aircraft flowfields and aerodynamics. The computational results were all performed with hybrid RANS/LES formulations, with an emphasis on unsteady flows and subsequent aerodynamics, and results from five computational methods are included. The work was focused on one particular low-speed, high angle-of-attack flight test condition, and comparisons against flight-test data are included. This work represents the third coordinated effort using the F-16XL aircraft, and a unique flight-test data set, to advance our knowledge of slender airframe aerodynamics as well as our capability for predicting these aerodynamics with advanced CFD formulations. The prior efforts were identified as Cranked Arrow Wing Aerodynamics Project International, with the acronyms CAWAPI and CAWAPI-2

Investigating and quantifying molecular complexity using assembly theory and spectroscopy

Current approaches to evaluate molecular complexity use algorithmic complexity, rooted in computer science, and thus are not experimentally measurable. Directly evaluating molecular complexity could be used to study directed vs undirected processes in the creation of molecules, with potential applications in drug discovery, the origin of life, and artificial life. Assembly theory has been developed to quantify the complexity of a molecule by finding the shortest path to construct the molecule from building blocks, revealing its molecular assembly index (MA). In this study, we present an approach to rapidly infer the MA of molecules from spectroscopic measurements. We demonstrate that the MA can be experimentally measured by using three independent techniques: nuclear magnetic resonance (NMR), tandem mass spectrometry (MS/MS), and infrared spectroscopy (IR). By identifying and analyzing the number of absorbances in IR spectra, carbon resonances in NMR, or molecular fragments in tandem MS, the MA of an unknown molecule can be reliably estimated. This represents the first experimentally quantifiable approach to determining molecular assembly. This paves the way to use experimental techniques to explore the evolution of complex molecules as well as a unique marker of where an evolutionary process has been operating

Research of working area development parameters in conditions of deep steep deposit finalizing

Отримано формули розрахунку об’єму запасів корисних копалин в приконтурній та глибинній зоні. Встановлено характер впливу параметрів доробки глибоких крутоспадних родовищ відкритим способом на доцільне положення поточних та проектних контурів кар’єру. Встановлено, що найменший середній коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу в проектному положенні. Найменший поточний коефіцієнт розкриву досягається при мінімальному значенні суми обсягів корисної копалини приконтурної зони лежачого і висячого боків покладу, а також робочого борту кар'єру в поточному положенні

Human Papillomavirus Genotype Distribution in Czech Women and Men with Diseases Etiologically Linked to HPV

The HPV prevalence and genotype distribution are important for the estimation of the impact of HPV-based cervical cancer screening and HPV vaccination on the incidence of diseases etiologically linked to HPVs. The HPV genotype distribution varies across different geographical regions. Therefore, we investigated the type-specific HPV prevalence in Czech women and men with anogenital diseases.We analyzed 157 squamous cell carcinoma samples, 695 precancerous lesion samples and 64 cervical, vulvar and anal condylomata acuminate samples. HPV detection and typing were performed by PCR with GP5+/6+ primers, reverse line blot assay and sequencing. samples. HPV types 6 and/or 11 were detected in 84% samples of condylomata acuminate samples.The prevalence of vaccinal and related HPV types in patients with HPV-associated diseases in the Czech Republic is very high. We may assume that the implementation of routine vaccination against HPV would greatly reduce the burden of HPV-associated diseases in the Czech Republic

Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism

Becoming a phenotypic male is ultimately determined by androgen-induced masculinization. Disorders of fetal masculinization, resulting in hypospadias or cryptorchidism, are common, but their cause remains unclear. Together with the adult-onset disorders low sperm count and testicular cancer, they can constitute a testicular dysgenesis syndrome (TDS). Although masculinization is well studied, no unifying concept explains normal male reproductive development and its abnormalities, including TDS. We exposed rat fetuses to either anti-androgens or androgens and showed that masculinization of all reproductive tract tissues was programmed by androgen action during a common fetal programming window. This preceded morphological differentiation, when androgen action was, surprisingly, unnecessary. Only within the programming window did blocking androgen action induce hypospadias and cryptorchidism and altered penile length in male rats, all of which correlated with anogenital distance (AGD). Androgen-driven masculinization of females was also confined to the same programming window. This work has identified in rats a common programming window in which androgen action is essential for normal reproductive tract masculinization and has highlighted that measuring AGD in neonatal humans could provide a noninvasive method to predict neonatal and adult reproductive disorders. Based on the timings in rats, we believe the programming window in humans is likely to be 8-14 weeks of gestation