Dual boundary element analysis of edge cracked structures

For elastostatics problems in general, the displacement boundary integral equation (BIE) has been used with a great deal of success. For elastostatics problems involving a crack, however, the displacement BIE alone is not sufficient in a single region formulation. This is because the two crack boundaries occupy exactly the same position leading to degeneracy in the description of the problem. This difficulty can be overcome by using the so-called traction boundary integral equation on one of the crack boundaries, while the displacement BIE is used on the other crack boundary, and on the outer boundary. This allows one to formulate the entire problem in a single region analysis, generally referred to as the dual boundary integral equation formulation. The present work deals with 2D structures containing a surface breaking crack. The boundary of the structure is discretized into a number of elements; depending on the type, each element is described by a number of nodes. The dual BIE is formed into a system of linear equations by collocation at all the nodes. The crack tip stress intensity factors and the crack growth parameters are calculated. One of the main challenges in Boundary Elements is dealing with fundamental solutions containing mathematical singularities. The displacement BIE contains strongly singular fundamental solutions, while the traction BIE contains fundamental solutions which are even more strongly singular (or hypersingular) in nature. These singular (and hypersingular) integrals have to be evaluated in a special manner, which places some restrictions on the order of continuity of the displacements and tractions on the boundary, as well as on the smoothness of the boundary. These considerations are taken care of during the modeling process. A Green\u27s function library has been implemented whereby a portion of the discretized Green\u27s function is saved, and is used later to reduce the computation time. An interactive Graphical User Interface serves as a front-end to the utility developed. Together with the ability to interactively change the crack geometry and pose What if? questions, this work provides a powerful tool in fracture mechanics

The μ\mu-τ\tau mixed symmetry and neutrino mass matrix

We propose an elegant neutrino mass matrix texture entitled $\mu$-$\tau$ mixed symmetry highlighting two simple correlations among its elements and a detailed analysis is carried out to see its phenomenological implications. The proposed texture is motivated in the framework of Seesaw mechanism in association with $A_4$ symmetr

New-onset hyperglycemia: a potential clue to detect early pancreatic cancer

Pancreatic adenocarcinoma has an incidence rate nearly equal to the mortality rate and this is mostly due to late symptom onset and diagnosis. Evidence has indicated that new-onset diabetes may be a manifestation of occult pancreatic carcinoma. Authors report the case of a young female who presented with new-onset severe hyperglycemia and superficial thrombophlebitis. She was subsequently diagnosed with pancreatic cancer confirmed by histopathology. Her glycemic status evaluated 6 months prior to her presentation during institutional health check-up was entirely normal. This case report will serve to emphasize that new-onset diabetes in certain patients could be a presenting feature of pancreatic cancer.Pancreatic adenocarcinoma has an incidence rate nearly equal to the mortality rate and this is mostly due to late onset of symptoms and delay in diagnosis. Early diagnosis of this cancer gives the opportunity for total resection of pancreas and creates hope for a full recovery. Compelling evidence now indicates that new-onset diabetes may be a manifestation of occult pancreatic carcinoma. Authors report a young female who presented with new-onset severe hyperglycemia and superficial thrombophlebitis. She was subse­quently diagnosed with pancreatic cancer confirmed by histopathology. Her glycemic status evaluated 6 months prior to her presentation during institutional health check-up was entirely normal. This case report will serve to emphasize that new-onset diabetes in certain patients could be a presenting feature of pancreatic cancer. (Clin Diabetol 2017; 6, 3: 115–117

Comparative study of some routinely measured Serum biochemical parameters between acute exacerbation of Chronic Obstructive Pulmonary Disease and stable Chronic Obstructive Pulmonary Disease patients in a tertiary care hospital of Kolkata: an attempt to make simple prognostic indicators

Background: Patients with COPD often have exacerbations which frequently require hospitalization, resulting in higher mortality rates and costs than patients managed at OPD. Some easily available blood parameters in both stable COPD and AECOPD patients are measured that can be done in every patient even in poor resource settings. Finally, Results were analysed statistically to find out if there is any presence of significant difference of biochemical profile in stable COPD patients and AECOPD patients with or without any prognostic significance.Methods: In institution based observational case control study, authors measured 1.  FBS and PPBS 2. Serum Urea and Creatinine 3. Serum Electrolytes- Na+, K+, Cl- 4. LFT  5. Uric acid in both stable COPD(n=50) and AECOPD (n=50) patients. Finally, Results were analysed statistically to find out if there is any presence of significant difference of biochemical profile in stable COPD patients and AECOPD patients.Results: AECOPD patients had statistically significant higher urea, uric acid levels and higher fasting hyperglycemia than stable COPD patients. Hypernatremia, hyponatremia and hyperkalemia, hypokalemia - all were significantly higher in AECOPD group. Low level of serum bilirubin and higher level of AST and ALP were common in AECOPD patients. AECOPD patients with high urea value (>50 mg/dl) (but not high creatinine) was associated with poor patient outcome in respect to ICU transfer, death and prolonged hospital stay. Low bilirubin, high ALP and AST level in AECOPD patients was associated with higher ICU transfer and mortality but only high ALP level was associated with prolonged hospital stay. High uric acid level (>6 mg/dl) was a major determinant of ICU transfer, mortality and prolonged hospital stay.Conclusions: Predicting exacerbation by these parameters early in the course of disease can decrease morbidity and mortality as well as health care cost to great extent. By measuring the changes in it can also be predicted early who will need ICU support in future and who can be treated at ward

Notes on the discovery and ecology of the invasive armoured catfish Pterygoplichthys disjunctivus (Weber, 1991) and the exotic cichlid Amphilophus trimaculatus (Gunther, 1867) from Southern West Bengal, India

This paper documents the first occurrence of the exotic, highly invasive, South American armoured sucker mouth catfish Pterygoplichthys disjunctivus (Weber, 1991) from the brackish waters of the Sundarban Tiger Reserve, West Bengal, India and the Central American cichlid Amphilophus trimaculatus (Gunther, 1867) from Southern Bengal, India. Notes on the possible threats due to invasion, sources of introduction, extent of spread and management of these and other invasive species are discussed in the paper