A major issue nowadays that concerns the pollution of the environment is the emissions emerging from heavy-duty internal combustion engines. Such concern is dictated by the fact that the electrification of heavy-duty transport still remains quite challenging due to limitations associated with mileage, charging speed and payload. Further improvements in the performance and emission characteristics of conventional heavy-duty diesel engines are required. One of a few feasible approaches to simultaneously improve the performance and emission characteristics of a diesel engine is to convert it to operate on Miller cycle. Therefore, this study was divided into two stages, the first stage was the simulation of a heavy-duty turbocharged diesel engine (4-stroke, 6-cylinder and 390 kW) to generate data that will represent the reference model. The second stage was the application of Miller cycle to the conventional diesel engine by changing the degrees of intake valve closure and compressor pressure ratio. Both stages have been implemented through the specialist software which was able to simulate and represent a diesel engine based on performance and emissions data. An objective of this extensive investigation was to develop several models in order to compare their emissions and performances and design a Miller cycle engine with an ultimate goal to optimize diesel engine for improved performance and reduced emissions. This study demonstrates that Miller cycle diesel engines could overtake conventional diesel engines for the reduced exhaust gas emissions at the same or even better level of performance. This study shows that, due to the dependence of engine performance on complex multi-parametric operation, only one model achieved the objectives of the study, more specifically, engine power and torque were increased by 5.5%, whilst nitrogen oxides and particulate matter were decreased by 30.2% and 5.5%, respectively, with negligible change in specific fuel consumption and CO2, as average values over the whole range of engine operating regimes.

No abstract

No abstract

A 73-year-old female presented to the emergency department with hemodynamic instability due to rapid atrial fibrillation (AF). She had been operated through a right thoracotomy, twice in the past, for bronchogenic cyst resection situated at the subcarinal space.Echocardiography showed a cysts-like structure inside the pericardial cavity, compressing the left atrium. Further investigation with computed tomography-scan and magnetic resonance imaging clarified the margins of the lesion. It was located in the posterior parietal pericardium between the origin of the superior pulmonary veins and showed no myocardial invasion (Figures 1 and 2).After standard median sternotomy and cardiopulmonary bypass, the cystic structure was accessed. After mobilizing the cyst from the left atrium, and the pulmonary veins it could be en bloc resected (Figure 3). The patient had an uneventful recovery and she is free of AF and other symptoms 28 months later.Histopathology confirmed the diagnosis of bronchogenic cyst excluding any malignancy.Bronchogenic cysts are the most common congenital cystic lesions of the mediastinum and are derived from the primitive foregut. They also occur in the lungs, diaphragm, retroperitoneum, thymus, neck, and very rare in the pericardium with an incidence of 1:42 000 patients. Patients with intrapericardial bronchogenic cysts may present with mild or moderate symptoms that include shortness of breath and chest pain, sometimes in association with arrhythmia.

Elastofibroma is a rare benign, soft-tissue slow-growing tumor seen predominantly in elderly females. We present such a case in a 46-year-old female. She presented with gradually increasing soft tissue swelling of 8×6 cm in the right inferior subscapular region. MRI showed a large intramuscular lesion with atypia. She underwent excisional biopsy and the histopathology and immunochemistry showed elastofibroma. We present this rare case to emphasize the important role of the diagnostic tools. A definitive diagnosis helps to avoid unnecessary wide and radical resection.