a. a. ranjbar

This article analyzes the effects of combustion type (conventional diesel, dual-fuel, and gas-fueled), structural material (Ductile cast iron and Gray cast iron), and thermal boundary conditions on the sensitive points of the heavy diesel engine cylinder head. The target engine in this numerical and experimental simulation is a 12-cylinder V-shaped heavy-duty medium-speed diesel engine with a turbocharger. The experiment begins by installing 14 sensors on cylinder head No. A6 due to the worst working condition of the engine. 3D simulation is performed using the Finite Volume Method (FVM) within the framework of ANSYS-Fluent 2021 software under time-variable conditions (18 min) and k-ε turbulent flow model. The outputs are as follows: with an increase of 24% of the TGas, the temperature of the bridge between the exhaust-exhaust and Inlet-Inlet valves for the Gray and Ductile cast iron cylinder head increases by about 20%. Meanwhile, with an increase of 36% from the heat transfer coefficient (HTC), the temperature of the bridge between the valves increases by 14%. The ratio of the effect of changes in the TGas to the HTC on the temperature of the bridge between the valves is about 1.9 for the cylinder head made of ductile cast iron and about 1.8 for the gray cast iron. Subcooled flow boiling will probably occur in the initial areas of the cylinder head, i.e. sensors 2, 5, 8, and 11 due to the temperature increase above 447.33K.

The two-phase fluid flow in the Heavy-duty diesel (HDD) engine water jacket coolant can greatly reduce the thermal load of the cylinder head. In this experimental work, the characteristic of two-phase fluid flow in a transparent Plexiglas channel using C2H6O2- H2O (50%–50%) is investigated. Gray cast iron surfaces were selected as the heated surfaces to simulate the material of the HDD-cylinder head. Operating conditions of the HDD- engine (i.e. Vinlet from 0.46 to 2.0 m/s, Psystem from 1 to 2 bar and Tinlet from 70 to 110°C) are optimized using Response Surface Method (RSM) within the framework of the Central Composite Design (CCD) model. The outputs indicate: the onset of nucleate boiling (ONB) temperature increases by about ≈ 11.92% when the pressure changes from 1 to 2bar. By reducing the inlet temperature (from 70 to 110℃), the effect of superheating disappears around the bubble, so to reach the non-linear (i.e. two-phase region) area, the heat flux must be increased between 10 to 15 kW/m2 to observe the ONB point. The cooling system pressure at low velocities (i.e. < 1m/s) should be considered in such a way that the saturation temperature of the fluid is about 35 to 50℃ lower than the HDD-engine wall temperature. Instead, at high velocities (i.e  1m/s) this temperature difference between the fluid saturation temperature and the wall temperature is about 55 to 85℃.

Coronary artery diseases (CAD) are the most common, costly and debilitating diseases and identify factors that may help predict where necessary. The purpose of study was evaluation the correlation between the earlobe crease (ELC) and coronary artery disease in patients referred for coronary angiography in Rafsanjan. We evaluated 320 patients in coronary angiography department for ELC and severity of CAD and other variables. Data analyzed with chi-Square and logistic regression. 68.8% had CAD that 32.7% of them had no ELC, 43.6% moderate ELC and 23.6% severe that difference was significant (p=0.01). Difference between ELC was significance with cigar (p=0.014), hyperlipidemia (P<0.001), history of CAD (P=0.048), age and bady mas index (P<0.001). ELC, hyperlipidemia and age can predict CAD significantly. It seems that this Dermatologic finding able to predict the risk of CAD in normal population and perhaps even in emergencies such surgeries.

Cutaneous leishmaniasis due to Leishmania major has become a hot topic in Iran. The objective of this study was to determine some ecological aspects of sand flies in the study area. Sand flies were collected biweekly from indoors and outdoors fixed places in the selected villages, using 30 sticky paper traps from the beginning to the end of the active season of 2006 in Kerman Province, south of Iran. The flies were mounted and identified. Some blood fed and gravid female sand flies of rodent burrows and indoors were dissected and examined microscopically for natural promastigote infection of Leishmania parasite during August to September. In total, 2439 specimens comprising 8 species (3 Phlebotomus and 5 Sergentomyia) were identified. The most common sand fly was P. papatasi and represented 87.1% of sand flies from indoors and 57.2% from outdoors. The activity of the species extended from April to end October. There are two peaks in the density curve of this species, one in June and the second in August. Natural promastigote infection was found in P. papatasi (12.7%). Phlebotomus papatasi is considered as a probable vector among gerbils and to humans with a high percentage of promastigote infection in this new focus of cutaneous leishmaniasis. The Bahraman area which until recently was unknown as an endemic area seems now to represent a focus of zoonotic cutaneous leishmaniasis transmission in Iran.

Hand surgery is a distinguished sub-specialty of trauma and orthopedic management. Sprains and dislocations of the interphalangeal joint of the finger are relatively rare due to the protected position of this joint in the hand. However, unusual cases of a simultaneous Proximal and Distal Interphalangeal Joint Dislocation have been reported. We report this rare case of simultaneous dislocation of both interphalangeal joints of the little finger from Northern Iran. We observed that the mechanism, diagnosis and treatment of our case were similar to the published reports of the world literature. The patient had closed reduction of distal interphalangeal joint with excellent postoperative recovery. The importance of careful assessment of hand injuries with stress test of the joints under local anesthesia is reiterated. In conclusion, we recommend that this injury of rare occurrence be treated conservatively by manipulation, and if a good functional result is desired, adequate physiotherapy treatment is also required.