Genetic Algorithm & Fuzzy Logic Based PEM Fuel Cells Power Conversion System for AC Integration

In the scientific environment, the leading variables such as voltage, current, power, heat from cooling system, membrane temperature and hydrogen pressure are uses as steady state and transient behaviors of Fuel Cells (FC). In the reproducing process of Fuel Cells (FC) variations, DC-DC converters are connected transversely its terminals, the efficiency, stability and durability are considered as operational problems for steady state. Since the Proton Exchange Fuel Cell is a non-linear process and its parameters change when it is delivering energy to the grid. The conventional controllers can’t content the control objectives. In this paper, an intelligent DC-AC power optimization is proposed for Fuel Cell (FC) control system to produce energy in the grid stations and to improve the power quality when FC is supplying load to grid. Furthermore, a Genetic Algorithm (GA) based reactive power optimization for voltage profile improvement and real power minimization in DC-AC system. A fuzzy logic controller is also used to control active power of PEM fuel cell system. Fuzzy logic controller will modify the hydrogen flow feedback from the terminal load. At the end, we will simulate DC-AC converter for checking its efficiency, stability and durability on the basis of the genetic algorithm and fuzzy logic controller to control power generation

Genetic Algorithm & Fuzzy Logic Based PEM Fuel Cells Power Conversion System for AC Integration

In the scientific environment, the leading variables such as voltage, current, power, heat from cooling system, membrane temperature and hydrogen pressure are uses as steady state and transient behaviors of Fuel Cells (FC). In the reproducing process of Fuel Cells (FC) variations, DC-DC converters are connected transversely its terminals, the efficiency, stability and durability are considered as operational problems for steady state. Since the Proton Exchange Fuel Cell is a non-linear process and its parameters change when it is delivering energy to the grid. The conventional controllers can’t content the control objectives. In this paper, an intelligent DC-AC power optimization is proposed for Fuel Cell (FC) control system to produce energy in the grid stations and to improve the power quality when FC is supplying load to grid. Furthermore, a Genetic Algorithm (GA) based reactive power optimization for voltage profile improvement and real power minimization in DC-AC system. A fuzzy logic controller is also used to control active power of PEM fuel cell system. Fuzzy logic controller will modify the hydrogen flow feedback from the terminal load. At the end, we will simulate DC-AC converter for checking its efficiency, stability and durability on the basis of the genetic algorithm and fuzzy logic controller to control power generation

Stone clearance in lower pole nephrolithiasis after extra corporeal shock wave lithotripsy – the controversy continues

BACKGROUND: To determine factors influencing the clearance of fragments after extra-corporeal shock wave lithotripsy (ESWL) for lower pole calyceal (LPC) stones. METHODS: In the period between July 1998 and Oct 2001, 100 patients with isolated lower polar calyceal calculi ≤ 20 mm, in patients aged ≥ 14 years, were included in the study. Intravenous urograms (IVU) were reviewed to define the LPC anatomy (width of the infundibulum and pelvicalyceal angle). Study end points i.e. stone free status; number of shock waves used and number of sessions were correlated with variables like LPC anatomy, body mass index and stone size. RESULTS: At three months follow up the clearance for stone size ≤ 10 mm, 11–15 mm and 16–20 mm were 95, 96 and 90% respectively. Patients with acute LPC (<90°) and obtuse angle (>90°) had stone clearance of 94 and 100% respectively. For the infundibular width of < 4 mm, the stone clearance was 93% were as for > 4 mm, it was 100%. For body mass index (BMI) less than and > 30 kg/m(2), the stone clearance was 92 and 95% respectively. CONCLUSIONS: There is a trend towards more ESWL sessions and shock wave requirement in patients with acute pelvi-calyceal angle and narrow infundibulum but it is not statistically significant. Size (≤ 20 mm) and BMI has no relation with stone clearance. With modern lithotripter, stones up to 20 mm could primarily be treated by ESWL, irrespective of an un-favorable lower polar calyceal anatomy and body habitus

Al Makhthutot Al Arabiyyah : Fihrisatiha Alamiyan Wa Amaliyan

239 hal.; 24 c

Is there a difference in early perioperative morbidity in transurethral resection of prostate (TURP) versus TURP with cystolitholapaxy and TURP with inguinal herniorrhaphy?

Objective of this study is to determine the difference in early peri-operative morbidity of transurethral resection of prostate (TURP) and if it is combined with inguinal hernia repair and mechanical and/or pneumatic fragmentation of bladder calculus. All patients undergoing TURP, cystolitholapaxy (CLL), inguinal hernia repair (IHR) or any combination between January 1997 and December 1999 were identified using ICD 9CM coding and indexing system. Overall 1273 patients were identified, charts were reviewed for demographics, pre-operative parameter, intra-operative data and early peri-operative morbidity. In the three year period, 19 patients had TURP and inguinal herniorrhapy (IHR), 17 patients had TURP and cystolitholapaxy (CLL), 2 patients had TURP+IHR+CLL performed simultaneously; in the same period 346, 815, 74 patients had TURP, IHR, and CLL alone respectively. All the groups were matched for age, presentation and Co-morbidities. There was significant difference in the operating time between the different groups. Complications were not significantly different in the TURP, IHR, CLL, TURP+IHR, and TURP+CLL. In conclusion, mean operative time for TURP+IHR is increased by a fraction of 168.3 for TURP+CLL by 109.8 and TURP+IHR+CLL is 202.1 over TURP alone, with no significant difference in morbidity between TURP and TURP+IHR and TURP+CLL

An Assessment of Biodiversity in Tabuk Region of Saudi Arabia: A Comprehensive Review

Biodiversity refers to all the type of species in one geographical region or ecosystem. It consists of plants, animals, bacteria, and other life forms. As an estimate, around 1.7 million species are on record globally and approximately 15,000&ndash;18,000 new species are added each year. Global climate change is accelerating species extinction due to habitat destruction. Further, various abiotic and biotic environmental factors are limiting the pattern of biodiversity in a geographical region. A change in species category from endangered to extinction occurs due to their physiological, morphological, and life history pattern, which limits them to a specific niche. Biodiversity is very important for energy production and flow, bioremediation, and biogeochemical cycling of nutrients in terrestrial to aquatic ecosystems and vice versa. It is further required for human existence in the form of food, fibers, medicines, and biological control. Therefore, consistent monitoring, assessment, and conservation of ecological habitats and diversity of flora and fauna of aquatic and terrestrial ecosystems is the need of the hour. In this article, we are presenting an assessment based upon the literature survey on the biodiversity of Tabuk region of Kingdom of Saudi Arabia. A comprehensive study on the biodiversity of plants, animals and microorganisms of the Tabuk region (Tabuk city, Tayma, Haql, Sharma, Duba, Al Wajh and Umluj, Al Zetah, Al Beda&rsquo;a, etc.) are included in this review. This study will be a landmark as it is conducted at the inception of NEOM project in Tabuk region. It will help the authorities to enhance the native green cover, decrease desertification, regenerate biodiversity in natural environments, and advance the quality of life, to achieve the objectives of the Saudi Green Initiative and VISION 2030. However, studies and investigations on Tabuk biodiversity are still limited and need further exploration. Recently, a joint work between King Salman Royal Natural Reserve (KSRNR) and Department of Biology of University of Tabuk is underway to monitor the baseline data of flora and fauna of this region

An Assessment of Biodiversity in Tabuk Region of Saudi Arabia: A Comprehensive Review

Biodiversity refers to all the type of species in one geographical region or ecosystem. It consists of plants, animals, bacteria, and other life forms. As an estimate, around 1.7 million species are on record globally and approximately 15,000–18,000 new species are added each year. Global climate change is accelerating species extinction due to habitat destruction. Further, various abiotic and biotic environmental factors are limiting the pattern of biodiversity in a geographical region. A change in species category from endangered to extinction occurs due to their physiological, morphological, and life history pattern, which limits them to a specific niche. Biodiversity is very important for energy production and flow, bioremediation, and biogeochemical cycling of nutrients in terrestrial to aquatic ecosystems and vice versa. It is further required for human existence in the form of food, fibers, medicines, and biological control. Therefore, consistent monitoring, assessment, and conservation of ecological habitats and diversity of flora and fauna of aquatic and terrestrial ecosystems is the need of the hour. In this article, we are presenting an assessment based upon the literature survey on the biodiversity of Tabuk region of Kingdom of Saudi Arabia. A comprehensive study on the biodiversity of plants, animals and microorganisms of the Tabuk region (Tabuk city, Tayma, Haql, Sharma, Duba, Al Wajh and Umluj, Al Zetah, Al Beda’a, etc.) are included in this review. This study will be a landmark as it is conducted at the inception of NEOM project in Tabuk region. It will help the authorities to enhance the native green cover, decrease desertification, regenerate biodiversity in natural environments, and advance the quality of life, to achieve the objectives of the Saudi Green Initiative and VISION 2030. However, studies and investigations on Tabuk biodiversity are still limited and need further exploration. Recently, a joint work between King Salman Royal Natural Reserve (KSRNR) and Department of Biology of University of Tabuk is underway to monitor the baseline data of flora and fauna of this region