A B S T R A C T

Swirl stabilised combustion is one of the most successful technologies for flame stabilisation in gas turbine combustors. Lean premixed combustion systems allow the reduction of NOx coupled with fair flame stability. The swirl mechanism produces an aerodynamic region known as central recirculation zone (CRZ) providing a low velocity

region where the flame speed matches the flow velocity, thus anchoring the flame whilst serving to recycle heat and active chemical species to the root of the former. Another beneficial feature of the CRZ is the enhancement of the mixing in and around this region. However, the mixing and stabilisation processes inside of this zone have shown to be extremely complex. The level of swirl, burner outlet configuration and combustor expansion are very important variables that define the features of the CRZ. The complex fluid dynamics and lean conditions pose a problem for stabilization of the flame. The

problem is even more acute when alternative fuels are used for flexible operation.

Therefore, in this paper swirling flame dynamics are investigated using computational fluid dynamics (CFD) with commercial software (ANSYS). A new generic swirl burner operated under lean-premixed conditions was modelled. A variety of nozzles were analysed using isothermal case to recognize the the behavers of swirl.

The investigation was based on recognising the size and strength of the central recirculation zones. The dimensions and turbulence of the Central Recirculation Zone were measured and correlated to previous experiments. The results show how the strength and size of the recirculation zone are highly influenced by both the shear layer surrounding the Central

Recirculation Zones (CRZ) and outlet configurations.

Abstract: In this work, we consider linear and nonlinear Volterra integral equations of the second kind. Here, by converting integral equation of the first kind to a linear equation of the second kind and the ordinary differential equation to integral equation we are going to solve the equation easily. The Adomian decomposition method or shortly (ADM) is used to find a solution to these equations. The Adomian decomposition method converts the Volterra integral equations into determination of computable components. The existence and uniqueness of solutions of linear (or nonlinear) Volterra integral equations of the second kind are expressed by theorems. If an exact solution exists for the problem, then the obtained series convergence very rabidly to that solution. A nonlinear term F(u) in nonlinear volterra integral equations is Lipschitz continuous and has polynomial representation. Finally, the sufficient condition that guarantees a unique solution of Volterra (linear and nonlinear) integral equations with the choice of the initial data is obtained, and the solution is found in series form. Theoretical considerations are being discussed. To illustrate the ability and simplicity of the method. A few examples including linear and nonlinear are provided to show validity and applicability of this approach. The results are taken from the works mentioned in the reference. 

Neurodegenerative disorders results in inflammatory processes, including inflammatory cytokine secretion and concomitant superoxide production. Acetylcholinesterase inhibitors (AChEIs) influence neuro degeneration through anti-inflammatory effects. Donepezil as an AChEIs also provide neuro protection. This study aimed to evaluate the effect of donepezil (DZ) as a potent acetyl-cholinesterase (AChE) inhibitor, L-NG-Nitroarginine methyl ester (L.NAME) as non-selective nitric oxide synthase inhibitor and 7-nitroindazole (7-NI) as a selective neuronal nitric oxide synthase (NOS) inhibitor against Amyloid beta-peptide (1-42) (Aβ(1-42)) induced neurological disorder. Rats were divided into six groups including control, Aβ(1-42) ,Aβ(1-42) +L-arginine, Aβ(1-42) +L-NAME ,Aβ(1-42) +7-NI, and Aβ(1-42) +DZ. Brain AChE, malondialdehyde, nitric oxide, super oxidedismutase, catalase, reduced glutathione, interleukin 1-beta (IL-1β) and tumor necrosis factor alpha (TNF-α) were measured. Also, brain fatty acids fractions were estimated by high performance liquid chromatography (HPLC). Aβ(1-42) significantly alter levels of brain antioxidant, inflammatory markers and fatty acids content compared to the control group. Treatment with L.NAME, 7-NI and especially DZ improve these parameters. Administration of acetylcholinesterase inhibitors such as DZ attenuates neurodegenerative disorders through decreasing oxidation and inflammation.

Keywords: Neurotoxicity, Aβ (1-42), Donepezil, Nitric oxide, 7-nitroindazole, Fatty acids, HPLC

Corruption is widespread in different regions in the world and exists in all countries, both

developed and undeveloped, in the public and private sectors. Just the rate of corruption is

different from one country to another. Corruption is a very important issue in the world today,

and it is very important to understand causes of corruption across the nations. Thus, corruption

has occupied minds of thinkers on different levels both political and economic. It can be a major

obstacle in the process of economic development. Hence, corruption has negative impacts on the

economic growth in any country that suffers from it. Thinkers seek different ways to diagnose

reasons for corruption, and they try to find a panacea to this problem because corruption impedes

the development of countries.