•Pavement layer thickness and modulus prediction using GPR and FWD tests.•Input generation for pavement M-E analysis from the nondestructive tests.•Pavement performance evaluation through the M-E ...analysis.
A Mechanistic-Empirical (M-E) design based pavement quality or performance prediction methodology incorporating nondestructive test such as Ground Penetrating Radar (GPR) and Falling Weight Deflectometer (FWD) tests is demonstrated in this study. To facilitate, three pavement sites, namely, US285, US54, and I-40 in New Mexico are selected for nondestructive tests such as GPR and FWD. It is observed that the GPR predicted AC layer thickness is more consistent than base layer thickness. The FWD test was also conducted on the same locations, and like GPR, backcalculated layer moduli also shows varying level of inconsistency in different pavement sections. Based on the GPR and FWD tests, each of these three sites is divided into two major areas: one with the mean and the other with the minimum layer thicknesses and modulus. Layer thicknesses as well as moduli are incorporated to the AASHTOWare-ME software to determine load related distresses such as bottom-up crack and rut. Based on the amount of bottom-up cracks, the US54 pavement section is predicted to fail during 15th year of its service life, and the time of failure can be very early in the area with minimum layer thickness and modulus. Based on the rut prediction, pavement sections in US54 and I-40 is predicted to fail early. Finally, this methodology is recommended to implement to perform pavement quality assessment incorporating GPR and FWD tests in both project and network levels.
The patient of the report is a six- month-old Libyan female, who presented with a history of fever, persistent cough, and an attack of seizure. The patient has been diagnosed with a case of brain ...Tuberculoma and cavitation in the right lung based on the Brain Magnetic resonance imaging and the Chest Computed tomography scan, respectively. Subsequently, the patient was treated with antituberculous drugs and corticosteroids. After finishing the treatment, the patient has been cured. This case illustrates the possibility of developing early disseminated tuberculosis during infancy and highlights the difficulties of the diagnosis during the early stages of the disease. The case emphasizes the benefits of early diagnosis and treatment to prevent severe consequences in infancy.
This study examines the influence of two interface styles (menu- and command-based) on the perceived ease of use, perceived usefulness, and behavioral intention of the user to use the system. We have ...treated the system interface style as an external factor in the technology acceptance model (TAM) to examine its direct and indirect effects on behavioral intention to accept and use a system. The results showed that the interface style had direct effects on perceived ease of use and perceived usefulness which, in turn, demonstrated significant effects on behavioral intention to use the system. Further, the results showed that perceptions of the menu-based interface were more favorable than perceptions of the command-based interface. These results provide several theoretical and practical implications for designing an effective system.
Previous studies by the authors have determined pavement responses under dynamic loading consid- ering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete ...（AC） layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stress-strain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling （FEM） technique. An instrumented pavement section on Interstate 1-40 near Albuquerque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy （n-values） defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface （UMAT） functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model parameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer （FWD） loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n （ 1 （anisotropy） to n - 1 （isotropy）. This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stressdependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.
The ability of titanium dioixide to split water into OH− and H+ species is heavily dependent on the behaviour of defects in the crystal structure at or near the surface. We present an in situ study ...of defect migration in rutile TiO2(110) conducted using X‐ray photoelectron spectroscopy (XPS). First, surface and subsurface defects were created in the crystal by argon ion sputtering. Subsequent in situ exposure of the defective crystal to liquid water healed the surface defects, whereas the subsurface remained defective. The sample was then annealed while XPS was used to monitor the concentration of titanium defects. At low annealing temperatures, Ti3+ was observed to migrate from the subsurface to the surface. Further annealing gradually restored the surface and subsurface to the defect‐free Ti4+ form, during which the changes in abundance of Ti1+, Ti2+ and Ti3+ defects are discussed.
Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis that belongs to the anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides. It usually presents with late ...onset asthma in association with ear, nose and throat, cardiac, lung and gastrointestinal involvement.
To present a case of EGPA man with an unusual presentation.
A 24 years old patient with EGPA presented with deep vein thrombosis and nerve palsy without a history of asthma or other usual manifestations of the disease. The left leg showed a skin rash and associated deep vein thrombosis as well as a small ulcer over the pulp of the right thumb. The total leucocyte count was 14.5 × 109/L (41% eosinophils), erythrocyte sedimentation rate was 30 mm/1st hour and C-reactive protein 12.2 mg/L. Hepatitis B and C serology, antinuclear antibody (ANA) and antiphospholipid antibodies were all negative. ANCA was positive: myeloperoxidase (MPO) 36.9 U/ml and proteinase-3 (PR3) 15.9 U/ml and urinalysis was normal. The dermal and subcutaneous blood vessels displayed fibrinoid deposits, necrosis, and neutrophilic infiltrates in keeping with vasculitis. The patient showed a prompt and good response to corticosteroid and rituximab therapy with resolution of his symptoms.
There is a necessity to keep an open eye for the diagnosis of EGPA in patients with eosinophilia even in the absence of asthma or other usual manifestations, as prompt therapy may be organ and life-saving. B cell therapy should be considered in patients resistant to conventional therapy and those in whom preservation of fertility is desired.
Measuring the cross-anisotropy of hot-mix asphalt Islam, Md Rashadul; Ahmed, Mesbah U.; Tarefder, Rafiqul A.
The international journal of pavement engineering,
03/2016, Letnik:
17, Številka:
3
Journal Article
Recenzirano
This study measures the cross-anisotropy of gyratory, kneading and field-compacted hot-mix asphalt samples of two sizes. One set of cube samples were subjected to compression through the top face and ...the other set through the side face. In addition, two sets of beam samples were tested for flexure stiffness using load on both the top and side faces. Results show that the side faces can sustain an average compressive stress of 0.89, 0.91 and 0.77 times of the top faces for kneading, gyratory and field-compacted cube samples, respectively. The average flexure stiffness of the side face is 0.85 times of that of the top face. For comparison, finite element model (FEM) was developed to predict pavement stress-strain under wheel load. In addition, stress-strain data from a field-instrumented pavement section on Interstate 40 in New Mexico were collected. The FEM-simulated vertical stress shows a close match with collected stress at cross-anisotropy value of 0.8.
The effects of cross-anisotropy of unbound layer materials on the stress-strain response of a pavement under Falling Weight Deflectometer (FWD) test load are determined at three temperatures ...employing a dynamic Finite Element Model (FEM) in ABAQUS. Viscoelastic behavior of Asphalt Concrete (AC) is characterized by laboratory dynamic modulus test. Nonlinear elasticity of base material is incorporated through a User Defined Material (UMAT) subroutine. Cross-anisotropy is introduced by changing the ratio of horizontal to vertical stiffness (n-value) of unbound layers. FEM model is validated using field collected stress-strain under FWD test on the instrumented pavement section at mile post 141 (MP 141) on Interstate 40 (I-40) near Albuquerque, New Mexico. It is observed that tensile strain at the bottom of the AC layer is influenced by the base layer cross-anisotropy whereas vertical strain in this layer is barely affected by the cross-anisotropy of the unbound layers. However, vertical strains in the unbound layers are significantly affected by cross-anisotropy. Therefore, it can be postulated that fatigue damage by tensile strain at the bottom of AC layer, and rutting by vertical strain should be evaluated for unbound layer cross-anisotropy in the pavement design. Overall, strain responses due to cross-anisotropy are highly sensitive to temperature.
PDF
