Hakan Ozcan

Extradigital glomus tumor of the triceps tendon as a cause of elbow pain: a case report

G lomus tumors are rare benign vascular tumors first described by Wood in 1812.5 Of all of the upper extremity tumors, they are the most interesting and worth investigating because of their clinical findings. Clinically, glomus tumors are characterized by a triad of temperature sensitivity, severe pain, and localized tenderness.2,3 Often these are unique positive diagnostic findings of a tumor, although several diagnostic methods have also been used. The lesion is usually located in the hand, especially the nail bed of the distal phalanx, but it may occur anywhere.1,2,4-7 We report a rare case of glomus tumor in the tendon of the triceps. It caused severe pain and limitation of the elbow joint.

The effects of heat transfer on the exergy efficiency of an air-standard otto cycle

The exergy analysis of an air-standard Otto cycle with heat transfer loss is analyzed by using finite-time thermodynamics. The results showed that the heat transfer loss is responsible for a significant destruction of exergy. It is also shown that exergy efficiency and maximum power output increase with decreasing heat transfer loss. The results obtained in this paper may provide useful information for the maximum work available.

Effect of water addition on the exergy balances of an LPG fuelled spark ignition engine

In this paper, we investigate the effect of water addition on the exergy balance of a conventional engine. The present work is an analytical study depending on experimental measurements. A four-cylinder, LPG fuelled SI engine is used in this work, and water injection through intake manifold is used for water addition. The cylinder pressure versus crank angle, and water, air and fuel flow rates are measured during tests. The water injection is accomplished over water to fuel mass ratios of 0.5 to examine the corresponding second-law properties. The results of the exergy analysis of engine operation with water injection are compared with the results of similar analysis for no water injection cases. It is found that water injection increases the combustion irreversibility significantly.

Second-law analysis of an LPG-powered 4-stroke SI engine under variable stroke length and compression ratio

A second-law analysis of an LPG-powered, 4-stroke, single-cylinder, water-cooled, variable stroke length spark-ignition engine was carried out to assess the engines energy efficiency. The engine was simulated at each stroke length/compression ratio combination. The second law of thermodynamics with the aid of the first law represents the results of entropy generation, reversible work output and exergy destruction of combustion processes of propane fuel. This work shows that, from the second-law analysis point of view, lowering the bore-to-stroke ratio increases the fuel availability and minimises the destruction of thermodynamic availability in LPG combustion. It also minimises the availability transfer due to heat and improves the availability transfer due to work.

Subtrochanteric Derotation Osteotomy Using a Bent Dynamic Compression Plate in Children With Medial Femoral Torsion

Subtrochanteric osteotomy of the femur using a bent dynamic compression plate is a simple, safe, and stable technique for correction of severe medial femoral torsion.

Combustion performance and emissions of diesel/biodiesel blended fuels in a residential reverse flame boiler

This paper presents an experimental study on the performance of diesel and biodiesel blended fuels in a water-cooled flame tube boiler. The combustion performance and gas emissions of B10, B20 and B30 were studied and these were compared with the diesel fuel. To investigate the combustion characteristics of biodiesel blends, including pure diesel, the temperature distributions in the combustion chamber and smoke tube, exhaust temperature, and exhaust gas emissions were determined. The results showed that the size of the peak temperature zones in the combustion chamber decreased gradually from B0 to B30. As a consequence of reduced temperatures in combustion chamber, NOx emissions decreased from 53 to 47 ppm and CO emissions increased slightly from 9.6 to 12.8 ppm. Also, CO2 emissions decreased from 13.2 to 12.8 with increasing biodiesel ratio in the diesel fuel. Results also showed that the thermal efficiencies of diesel/biodiesel blended fuels remained almost the same.

Second law analysis of a spark ignition engine under high values of ignition retard

The availability analysis of an Spark-Ignition (SI) engine under High Values Ignition Retard (HVIR) was investigated. Liquefied Petroleum Gas (LPG) was used as fuel. The results obtained in this paper may provide guidance to determine the proper ignition retard timing for cold-start emissions control. Results showed that cylinder pressure, availability transfer by heat and availability transfer by work significantly decreased as the spark timing was changed from normal to most retarded timing. Finally, as the spark timing was changed from normal timing to the most retarded timing, the availability transfer due to net exhaust flow and availability destruction due to combustion were significantly increased.