CALIBRATION OF CYCLIC CONSTITUTIVE MODELS FOR SOILS BY OSCILLATING FUNCTIONS

In order to minimize the probability of foundation failure resulting from cyclic action on structures, researchers have developed various constitutive models to simulate the foundation response and soil interaction as a result of these complex cyclic loads. The efficiency and effectiveness of these model is majorly influenced by the cyclic constitutive parameters. Although a lot of research is being carried out on these relatively new models, little or no details exist in literature about the model based identification of the cyclic constitutive parameters. This could be attributed to the difficulties and complexities of the inverse modeling of such complex phenomena. A variety of optimization strategies are available for the solution of the sum of least-squares problems as usually done in the field of model calibration. However for the back analysis (calibration) of the soil response to oscillatory load functions, this paper gives insight into the model calibration challenges and also puts forward a method for the inverse modeling of cyclic loaded foundation response such that high quality solutions are obtained with minimum computational effort. Therefore model responses are produced which adequately describes what would otherwise be experienced in the laboratory or field

Occipital Condyle Fracture – A Diagnosis Requiring High Suspicion

Traumatic injury causing occipital condyle fractures (OCF) are very rare. They are of critical clinical importance owing toimportant anatomical structures that need considerations of the occiput-atlantoaxial joint complex. Early diagnosis is of paramount importance since there may be associated lower cranial nerve palsies along with cervical spinal instability. Sometimes, this can be a diagnostic challenge in acute stage because of the inability to diagnose this injury with plain radiographs. To avoid this, high index of suspicion and relevant investigation of the craniocervical junction is indicated. Hence it helps in early recognition and diagnosis of OCF thus preventing possible neurological impairment. Here, we report a case of a 58 -year-old male who presented with complaints of neck pain and headache following physical assault

Nepal paediatric society clinical guidance for management of sepsis and septic shock in the paediatric intensive care units in Nepal

Justification: Sepsis is a major cause of morbidity and mortality in Nepal. There is a lack of standardisation in the management of severe sepsis and septic shock. Additionally, international guidelines may not be completely applicable to resource limited countries like Nepal. Objective: Create a collaborative standardised protocol for management of severe sepsis and septic shock for Nepal based on evidence and local resources. Process / Methods: Paediatricians representing various paediatric intensive care units all over Nepal gathered to discuss clinical practice and delivery of care of sepsis and septic shock under the aegis of Nepal Paediatric Society. After three meetings and several iterations a standardised protocol and algorithm was developed by modifying the existing Surviving Sepsis Guidelines to suit local experience and resources. Recommendations: Paediatric sepsis and septic shock definitions and management in the early hours of presentation are outlined in text and flow diagram format to simplify and standardise delivery of care to children in the paediatric intensive care setting. These are guidelines and may need to be modified as necessary depending on the resources availability and lack thereof. It is recommended to analyse data moving forward and revise every few years in the advent of additional data

Inverse analysis of cyclic constitutive models for unsaturated soil under consideration of oscillating functions

In order to assess the probability of foundation failure resulting from cyclic action on structures and to minimize the prediction error, various existing constitutive models considering cyclic loaded dry soils were extended to unsaturated soil conditions by the authors, thus requiring further calibration during application on existing slightly variable soil condition as well as the soil heterogeneities. The efficiency and effectiveness of these models is majorly influenced by the cyclic constitutive parameters and the soil suction. Little or no details exist in literature about the model based identification and the calibration of the constitutive parameters under cyclic loaded soils. This could be attributed to the difficulties and complexities of the inverse modeling of such complex phenomena. A wide variety of optimization strategies for the solution of the sum of least-squares problems as usually done in the field of model calibration exists, however the inverse analysis of the unsaturated soil response under oscillatory load functions has not been solved up to now. This paper gives insight into the model calibration challenges and also puts forward advanced optimization methods for the inverse modeling of cyclic loaded foundation response on unsaturated soils

Inverse analysis of cyclic constitutive models for unsaturated soil under consideration of oscillating functions

In order to assess the probability of foundation failure resulting from cyclic action on structures and to minimize the prediction error, various existing constitutive models considering cyclic loaded dry soils were extended to unsaturated soil conditions by the authors, thus requiring further calibration during application on existing slightly variable soil condition as well as the soil heterogeneities. The efficiency and effectiveness of these models is majorly influenced by the cyclic constitutive parameters and the soil suction. Little or no details exist in literature about the model based identification and the calibration of the constitutive parameters under cyclic loaded soils. This could be attributed to the difficulties and complexities of the inverse modeling of such complex phenomena. A wide variety of optimization strategies for the solution of the sum of least-squares problems as usually done in the field of model calibration exists, however the inverse analysis of the unsaturated soil response under oscillatory load functions has not been solved up to now. This paper gives insight into the model calibration challenges and also puts forward advanced optimization methods for the inverse modeling of cyclic loaded foundation response on unsaturated soils

Stroke in a child with pulmonary tuberculosis and pleural effusion—An important clue for the diagnosis of disseminated central nervous system tuberculosis

Abstract Central nervous system tuberculosis (CNS‐TB) is one of the most devastating and life‐threatening conditions having high mortality and morbidity. Here, we report a 12‐year‐old child with pulmonary tuberculosis and pleural effusion presenting with ischemic stroke as an important manifestation of central nervous system tuberculosis

Pediatric brain abscess clinical profile, management and outcome at tertiary care centre in Nepal

ABSTRACTBackground: Brain abscess in pediatric population is serious life threatening problem. Many risk factors are associated with this entity like congenital heart disease, ear infection and immunocompromised state. Early diagnosis and treatment with minimal invasive procedure has good outcome. Materials and Methods: This is a hospital based cross-sectional study conducted at institute of Medicine (IOM), Tribhuvan University Teaching Hospital Kathmandu, Nepal over the period of 3 years between September 2014 to August 2017. Clinical profile, management and outcome were analyzed. Results: A total of 27 cases were taken for the surgical management in the present study. There were 18 male and 9 female with the male to female ratio of 2:1. Mean age of the study population was 7.08 years. Otogenic Abscess was the most common 37.03% (n=10) and the temporal lobe was the most common site (37.5%). Headache was the most common clinical presentation seen in 74.07 %. All the cases were initially managed with the burrhole and aspiration. Only 14.8 %( n=4) of cases subsequently required surgical excision of the abscess wall. Only18.5 %( n=5) of the cases required multiple session aspiration. Positive culture was seen in 25.9% (n=7). Pseudomonas aeruginosa and E.coli were the commonest organisms grown. Mortality rate was 3.7%.Conclusion: Modern advances in radio imaging and multidisciplinary team involvement has decreased the morbidity and mortality.Keywords: otogenic brain abscess; pediatric brain abscess; tubercular abscess. </p

Shifting paradigm in brain abscess management at tertiary care centre in Nepal

Aim: Brain abscess is a challenging clinical entity with substantial high case fatality rates despite significant advances in imaging techniques, laboratory modalities, surgical interventions, and antimicrobial treatment.Otogenic and cardiogenic sources are among the most common. Classic clinical presentation is seen in very few cases only. Burr hole with aspiration works well with good clinical outcomes. Control of primary source in cases of ear infection in the single setting results in good outcomes, reduces for additional surgery, and decreases the duration of hospital stay.Methods: This is prospective observational study conducted at Institute of Medicine, Tribhuvan University Teaching Hospital, Kathmandu, Nepal over the period of two and a half years (from September 2014 to March 2017).We analyzed the demographic profile, management strategies and outcome of these cases diagnosed with brain abscess using Microsoft Excel 2007.Results: A total of 51 cases were undertaken for surgical management. There were 35 males and 16 females with the male to female ratio of 2.18:1. The mean age of the study population was 16.76 years with age range from 4 months to 60 years. Otogenic source was the most common. Temporal lobe was the most common abscess location. Headache was the most common clinical presentation and was seen in 86.27% of the study population. All cases were initially managed with burrhole and aspiration of the abscess. Only 3.92% (n = 2) of cases subsequently required surgical excision of the abscess wall. Only 11.76 % (n = 6) of the cases required multiple aspiration. Only 19.61% (n = 10) showed positive culture. Pseudomonas aeruginosa and E. coli were the most common organisms grown. Mortality rate among the study group was 3.92%.Conclusion: With the advent of modern technology in neuroimaging, mortality due to brain abscess has significantly decreased. Joint involvement of the otorhinolaryngology team and efforts in addressing the primary source have further helped in improving outcomes in cases of otogenic brain abscess. Hence, source control is of paramount importance in managing the brain abscess