Evaluation of the flame propagation within an SI engine using flame imaging and LES

This work shows experiments and simulations of the fired operation of a spark ignition engine with port-fuelled injection. The test rig considered is an optically accessible single cylinder engine specifically designed at TU Darmstadt for the detailed investigation of in-cylinder processes and model validation. The engine was operated under lean conditions using iso-octane as a substitute for gasoline. Experiments have been conducted to provide a sound database of the combustion process. A planar flame imaging technique has been applied within the swirl- and tumble-planes to provide statistical information on the combustion process to complement a pressure-based comparison between simulation and experiments. This data is then analysed and used to assess the large eddy simulation performed within this work. For the simulation, the engine code KIVA has been extended by the dynamically thickened flame model combined with chemistry reduction by means of pressure dependent tabulation. Sixty cycles have been simulated to perform a statistical evaluation. Based on a detailed comparison with the experimental data, a systematic study has been conducted to obtain insight into the most crucial modelling uncertainties

Unusual hyperthermia related to general anaesthesia in an Anatolian shepherd dog

This case report describes the diagnosis, the treatment options available in the absence of dantrolene and outcome of anaesthesia-related hyperthermia seen for the first time in an Anatolian shepherd dog. The case consisted of a nine-month-old male Anatolian shepherd dog with bilateral antebrachium fractures. For surgical treatment, the patient was pre-medicated with xylazine; anaesthesia was induced using ketamine and maintained with isoflurane. Approximately 40 minutes after isoflurane administration, tachypnoea, tachycardia, increase in body temperature and rigidity in the forelegs and masseter muscles was noticed. Inhalation anaesthesia was discontinued and hyperventilation was performed with 100% O-2. Due to its vasodilatory properties, diazepam was administered both to achieve muscle relaxation and to decrease body temperature. Alfentanil was used in an attempt to lower respiratory and heart rates. Intravenous administration of cold crystalloid solutions and external ice packs was used to lower body temperature. All these interventions kept the patient alive

Unusual hyperthermia related to general anaesthesia in an Anatolian shepherd dog

This case report describes the diagnosis, the treatment options available in the absence of dantrolene and outcome of anaesthesia-related hyperthermia seen for the first time in an Anatolian shepherd dog. The case consisted of a nine-month-old male Anatolian shepherd dog with bilateral antebrachium fractures. For surgical treatment, the patient was pre-medicated with xylazine; anaesthesia was induced using ketamine and maintained with isoflurane. Approximately 40 minutes after isoflurane administration, tachypnoea, tachycardia, increase in body temperature and rigidity in the forelegs and masseter muscles was noticed. Inhalation anaesthesia was discontinued and hyperventilation was performed with 100% O-2. Due to its vasodilatory properties, diazepam was administered both to achieve muscle relaxation and to decrease body temperature. Alfentanil was used in an attempt to lower respiratory and heart rates. Intravenous administration of cold crystalloid solutions and external ice packs was used to lower body temperature. All these interventions kept the patient alive

Granulosa Cell Tumor In A Spayed Young Queen

A four years old cat was presented to Clinic of Obstetrics and Gynaecology with complaints of weakness, inappetency, vomiting and estrus signs although it was spayed. Blood tests, radiography and ultrasonography revealed abdominal mass and uterine stump which were then removed surgically. Multilobular mass was defined as solid granulosa cell tumor (GCT). Increase of estrogen (E2) and insulin-like growth factor-1 (IGF- 1) values were detected on the 10th postoperative day. On the 40th postoperative day, the cat was brought to Internal Medicine Clinic with the complaints of weakness, inappetency and cachexia. Anemia, leucocytosis, uremia, hyperglycemia, sensitiveness and pain in the right abdomen were determined. A tumor was detected in the liver by radiography and ultrasonography and was suspected to be GCT metastasis. Despite medical therapy, the cat died after four months

Understanding the Influences of Thermal and Mixture Inhomogeneities on the Auto-Ignition Process in a Controlled Auto-Ignition (CAI) Engine Using LES

This work applies Large Eddy Simulation (LES) to the combustion process within a CAI engine. The chemical reaction is treated with a pre-tabulation approach based on homogeneous reactor simulations. At this juncture, a five-dimensional chemistry database is employed where the thermochemical properties are a function of the unburnt gas temperature, the air-fuel ratio, the exhaust gas ratio, the pressure, and the reaction progress variable. Statistical quantities are gathered for 20 simulated cycles and the averaged pressure curves get compared to measurements. The simulation data are then used to provide further insight into the auto-ignition process. It will be shown how thermochemical states are distributed within the cylinder and how the ignition quality depends on them. A statistical analysis is conducted to identify manifolds in the multi-dimensional scalar space along which the conditions leading to ignition evolve. Furthermore the strong influence in between consecutive cycles caused by the exhaust gas is investigated to identify the mechanism of cycle-to-cycle variations

Processionary Moths and Associated Urtication Risk: Global Change–Driven Effects

Processionary moths carry urticating setae, which cause health problems in humans and other warm-blooded animals. The pine processionary moth Thaumetopoea pityocampa has responded to global change (climate warming and increased global trade) by extending its distribution range. The subfamily Thaumetopoeinae consists of approximately 100 species. An important question is whether other processionary moth species will similarly respond to these specific dimensions of global change and thus introduce health hazards into new areas. We describe, for the first time, how setae are distributed on different life stages (adult, larva) of major groups within the subfamily. Using the available data, we conclude that there is little evidence that processionary moths as a group will behave like T. pityocampa and expand their distributional range. The health problems caused by setae strongly relate to population density, which may, or may not, be connected to global change