Experimental investigation of an improved exhaust recovery system for liquid petroleum gas fueled spark ignition engine

In this study, we have investigated the recovery of energy lost as waste heat from exhaust gas and engine coolant, using an improved thermoelectric generator (TEG) in a LPG fueled SI engine. For this purpose, we have designed and manufactured a 5-layer heat exchanger from aluminum sheet. Electrical energy generated by the TEG was then used to produce hydrogen in a PEM water electrolyzer. The experiment was conducted at a stoichiometric mixture ratio, 1/2 throttle position and six different engine speeds at 1800-4000 rpm. The results of this study show that the configuration of 5-layer counterflow produce a higher TEG output power than 5-layer parallel flow and 3-layer counterflow. The TEG produced a maximum power of 63.18 W when used in a 5-layer counter flow configuration. This resulted in an improved engine performance, reduced exhaust emission as well as an increased engine speed when LPG fueled SI engine is enriched with hydrogen produced by the PEM electrolyser supported by TEG. Also, the need to use an extra evaporator for the LPG fueled SI engine is eliminated as LPG heat exchangers are added to the fuel line. It can be concluded that an improved exhaust recovery system for automobiles can be developed by incorporating a PEM electrolyser, however at the expense of increasing costs

Mikrodiskektomi Operasyonu Sırasında Abdominal Aort Yaralanmasında Acil Hibrit Tedavi Stratejimiz: Nadir Görülen Olgu

Daha önceleri klasik lomber disk hernisi operasyonlarında, abdominal aort yaralanma olguları bildirilmiştir. Zamanla klasik disk hernisi operasyonu yerine, minimal invazif olması dolayısıyla mikrodiskektomi operasyonu yaygın olarak kullanılmaya başlandı. Son zamanlarda bu yöntemlerden mikrodiskektomi yöntemi daha sık tercih edilmektedir. Küçük cerrahi insiziyon, düşük kanama oranı ve iyi expojur sağlaması mikrodiskektomi yönteminin klasik yönteme göre bilinen avantajlarıdır. Literatürde, mikrodiskektomi operasyonuna bağlı olarak bildirilmiş abdominal aort yaralanması vakasına rastlayamadık. Bu olgu sunumunda, lomber disk hernisi nedeni ile operasyon planlanan, beyin cerrahisi kliniğinde mikrodiskektomi işlemi yapılırken aort yaralanması gelişen ve tedavide acil olarak endovasküler yöntem ile aort tamir uyguladığımız 62 yaşında kadın hastanın sunulması amaçlanmıştır

Theoretıcal Optımızatıon Of The P-N Type Semıconductor Materıal Paır In Thermoelectrıc Generator That Achıevement Exhaust Waste Heat Recovery

In this study, the effect of the use of different p-n type semiconductor materials in the thermoelectric generator designed to convert the exhaust waste heat energy of the internal combustion engines to electrical energy on the output parameters of the thermoelectric generator (load current, output voltage and power under load) is theoretically investigated. In the study, 4 different p-n pairs were formed for p-n pairs, forming thermoelectric modules, consisting of a combination of 4 different semiconductor materials of type Bi2Te3, Bi0.3Sb1.7Te3, PbSe0.5Te0.5 and Zn4Sb3. The thermoelectric generator using thermoelectric modules created from the determined p-n pairs was analyzed using the theoretical thermoelectric generator model developed in the Matlab/Simulink program in the previous study. In the theoretical model, the engine coolant temperature and flow values were used besides the temperature and flow rate of the exhaust gas obtained from experimental studies carried out in the 1500-4000 rpm range of a two-cylinder spark-ignition engine. The findings show that the thermoelectric generator produced the highest power output of the under the electrical load with the thermoelectric modules which is created using the Bi0.3Sb1.7Te3 and Bi2Te3 type semiconductors for the p-n pairs, respectively. Also, using the thermoelectric generator created by connecting twenty thermoelectric modules in series, 86.53 W (output current = 1.073 A and output voltage = 80.64 V) DC electrical power was obtained by the temperature difference of ΔT = 162.4 K at 4000 rpm engine speed

Investigation the effects of cilostazol and rosuvastatin on kidney and heart: An experimental acute kidney and heart injury model

Amaç: Bu çalışmada, deneysel bir modelde ameliyat öncesi silostazol ve rosuvastatin tedavisinin böbrek iskemi/reperfüzyon hasarına olan etkisi ve uzak kalp reperfüzyon hasarı üzerine olan etkisi araştırıldı.Ça lış ma pla nı: Toplam 35 adet dişi Sprague-Dawley sıçan rastgele beş gruba ayrıldı (n=7). Median laparotomi yapılarak, her iki böbreğe 45 dakika süren iskemi uygulandı. Cerrahi girişimin üç gün öncesinden başlayarak oral tedavi uygulandı (20 mg/kg silostazol, 10 mg/kg rosuvastatin ve 20 mg/kg cilostazol + 10 mg/kg rosuvastatin). Cerrahi girişimden bir gün sonra ise kan örnekleri ve böbrek ve kalp doku örnekleri alındı.Bul gu lar: değerlendirmesinde tümör nekroz faktör-alfa ve hipoksi ile indüklenebilir faktör-1 alfa immünreaktivitesinin silostazol, rosuvastatin ve silostazol + rosuvastatin grubunda, iskemi/reperfüzyon hasarı grubuna kıyasla anlamlı düzeyde daha düşük olduğu tespit edildi (p<0.05). Kalp dokularının immünhistokimyasal değerlendirmesinde tümör nekroz faktör-alfa immünreaktivitesi, iskemi/reperfüzyon hasarı grubuna kıyasla silostazol grubunda anlamlı düzeyde daha düşüktü. Hipoksi ile indüklenebilir faktör-1 alfa immünreaktivitesi, silostazol, rosuvastatin ve silostazol + rosuvastatin grubunda, iskemi/reperfüzyon hasarı grubuna kıyasla, anlamlı düzeyde daha düşüktü (p<0.05). İskemi/reperfüzyon hasarı grubuna kıyasla, silostazol, rosuvastatin ve silostazol + rosuvastatin grubunda, serum üre, kreatinin, kreatin kinaz-kas ve beyin ve troponin düzeyleri anlamlı düzeyde daha düşüktü (p<0.05).So nuç: Silostazol ve rosuvastatinin böbrek iskemi/reperfüzyon ve uzak kardiyak reperfüzyon hasarı üzerinde koruyucu etkileri olmakla birlikte, bu etki kombine tedaviye kıyasla silostazol tedavisi ile artabilir.Background: In this study, we aimed to assess the effects of preoperative cilostazol and rosuvastatin therapy on kidney ischemia/reperfusion injury and remote cardiac reperfusion injury in an experimental model.Methods: A total of 35 female Sprague-Dawley rats were randomly divided into five groups (n=7). Median laparotomy and a 45-min bilateral kidney ischemia were performed. Oral medications were administered three days before the surgical intervention (20 mg/kg cilostazol, 10 mg/kg rosuvastatin and 20 mg/kg cilostazol + 10 mg/kg rosuvastatin). Blood samples and kidney and heart tissue samples were extracted one day after surgery.Results: Immunohistochemical examination of the kidney samples revealed that tumor necrosis factor-alpha and hypoxia-inducible factor-1 alpha immunoreactivities in the cilostazol, rosuvastatin, and cilostazol + rosuvastatin groups were found to be significantly lower, compared to ischemia/reperfusion injury group (p&lt;0.05). Immunohistochemical examination of the heart samples revealed that tumor necrosis factor-alpha immunoreactivity was significantly lower in the cilostazol group, compared to ischemia/reperfusion injury group. Hypoxia-inducible factor-1 alpha immunoreactivities were significantly lower in the cilostazol, rosuvastatin, and cilostazol + rosuvastatin groups, compared to ischemia/reperfusion injury group (p&lt;0.05). Serum urea, creatinine, creatine kinasemuscle and brain, and troponin levels were significantly lower in the cilostazol, rosuvastatin, and cilostazol + rosuvastatin groups, compared to ischemia/reperfusion injury group (p&lt;0.05).Conclusion: Cilostazol and rosuvastatin have protective effects on kidney ischemia/reperfusion and remote cardiac reperfusion injury, and the protective effect can be augmented with cilostazol monotherapy, compared to combined therapy

Effect of pheniramine maleate on reperfusion injury in brain tissue.

BACKGROUND: The aim of this study was to investigate the protective effects of methylprednisolone (Pn), which is a potent anti-inflammatory agent, and pheniramine maleate (Ph), which is an antihistaminic with some anti-inflammatory effects, on reperfusion injury in brain developing after ischemia of the left lower extremity of rats. MATERIAL/METHODS: Twenty-eight randomly selected male Sprague-Dawley rats were divided into 4 groups: Group 1 was the control group, Group 2 was the sham group (I/R), Rats in Group 3 were subjected to I/R and given Ph, and rats in Group 4 were subjected to I/R and given Pn. A tourniquet was applied at the level of left groin region of subjects in the I/R group after induction of anesthesia. One h of ischemia was performed with no drug administration. In the Ph group, half of a total dose of 10 mg/kg Ph was administered intraperitoneally before ischemia and the remaining half before reperfusion. In the Pn group, subjects received a single dose of 50 mg/kg Pn intraperitoneally at the 30(th) min of ischemia. Brains of all subjects were removed after 24 h for examination. RESULTS: Malondialdehyde (MDA) levels of the prefrontal cortex were significantly lower in the Ph group than in the I/R group (p<0.05). Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were found to be significantly higher in the Ph group than in the I/R group (p<0.05). Histological examination demonstrated that Ph had protective effects against I/R injury developing in the brain tissue. CONCLUSIONS: Ph has a protective effect against ischemia/reperfusion injury created experimentally in rat brains