A Hepta-band Antenna Loaded with E-shaped Slot for S/C/X-band Applications

A compact planar multiband antenna operating at 3.1 (S-band) /4.7/6.4/7.6 (C-band) /8.9/10.4/11.8 GHz (X-band) is presented. The proposed Microstrip Patch Antenna (MSPA) consists of a rectangular radiator in which an E-shaped slot is etched out and a microstrip feed line. The E-shaped slot modifies the total current path thereby making the antenna to operate at seven useful bands. No external impedance matching circuit is used and the impedance matching at these bands are solely achieved by using a rectangular microstrip feed line of length 10mm (L6) and width 2mm (W10). The antenna has a compact dimension of and exhibits S11<-10dB bandwidth of about 6.45% (3.2-3.0GHz), 8.5% (4.9-4.5GHz), 7.6% (6.7-6.2GHz), 3.9% (7.8-7.5GHz), 5.7% (9.1-8.6GHz), 1.2% (10.44-10.35GHz) and 2.2% (11.87-11.62GHz). The simulation analysis of the antenna is carried out by using HFSS v.13.

A Hepta-band Antenna Loaded with E-shaped Slot for S/C/X-band Applications

A compact planar multiband antenna operating at 3.1 (S-band) /4.7/6.4/7.6 (C-band) /8.9/10.4/11.8 GHz (X-band) is presented. The proposed Microstrip Patch Antenna (MSPA) consists of a rectangular radiator in which an E-shaped slot is etched out and a microstrip feed line. The E-shaped slot modifies the total current path thereby making the antenna to operate at seven useful bands. No external impedance matching circuit is used and the impedance matching at these bands are solely achieved by using a rectangular microstrip feed line of length 10mm (L6) and width 2mm (W10). The antenna has a compact dimension of and exhibits S11<-10dB bandwidth of about 6.45% (3.2-3.0GHz), 8.5% (4.9-4.5GHz), 7.6% (6.7-6.2GHz), 3.9% (7.8-7.5GHz), 5.7% (9.1-8.6GHz), 1.2% (10.44-10.35GHz) and 2.2% (11.87-11.62GHz). The simulation analysis of the antenna is carried out by using HFSS v.13.

I – V characterization of vacuum deposited zinc selenide – silicon hetero junction

Zinc selenide (ZnSe) thin films were grown on silicon (Si) wafer by thermal evaporation and the hetero-structure was subjected to annealing at various temperatures. X-ray diffractogram recorded for various samples were analysed to extract the structural information including crystallite size, strain and dislocation density. ZnSe films exhibited cubic structure with (111) orientation and the crystallite size has increased from about 21 nm to 43 nm upon annealing at 673 K. Annealing at temperature above this has degraded the films. I – V characterization has shown nonlinear relation and affected by post deposition annealing. Thermionic emission and Cheung models were applied to obtain various parameters that assess the performance of hetero-structured devices. Minimum ideality factor was observed (n = 1.75 from Cheung Model) for as deposited system and it increased after annealing. Analysis has proven that series resistance increases after annealing under air ambienc

I – V characterization of vacuum deposited zinc selenide – silicon hetero junction

841-846Zinc selenide (ZnSe) thin films were grown on silicon (Si) wafer by thermal evaporation and the hetero-structure was subjected to annealing at various temperatures. X-ray diffractogram recorded for various samples were analysed to extract the structural information including crystallite size, strain and dislocation density. ZnSe films exhibited cubic structure with (111) orientation and the crystallite size has increased from about 21 nm to 43 nm upon annealing at 673 K. Annealing at temperature above this has degraded the films. I – V characterization has shown nonlinear relation and affected by post deposition annealing. Thermionic emission and Cheung models were applied to obtain various parameters that assess the performance of hetero-structured devices. Minimum ideality factor was observed (n = 1.75 from Cheung Model) for as deposited system and it increased after annealing. Analysis has proven that series resistance increases after annealing under air ambience

SVPWM based double loop control method of a three phase inverter for Microgrid Application

Many AC Microgrids required an inverter for converting power from DC to AC. Many control techniques are available and need a flexible control method which can able to regulate both the voltage at DC and AC side. The DQ method is developed in this paper by incorporated with space vector pulse width modulation (SVPWM) technique. A distribution generator (DG) is considered in this paper for connecting to utility grid through an inverter controlled by proposed double loop control technique. One voltage controlled loop and one current controlled loop are used in proposed control method to regulate both voltage and current. This paper showcases comprehensive findings using MATLAB/Simulink

A Validated RP-HPLC Method for the Determination of Impurities in Montelukast Sodium

Abstract: The present paper describes the development of a reverse phase chromatographic (RPLC) method for montelukast sodium in the presence of its impurities and degradation products generated from forced degradation studies. The drug substance was subjected to stress conditions of hydrolysis, oxidation, photolysis and thermal degradation. The degradation of montelukast sodium was observed under acid and oxidative environment. The drug was found to be stable in other stress conditions studied. Successful separation of the drug from the process impurities and degradation products formed under stress conditions were achieved on an Atlantis dC18 (250 x 4.6 mm) 5 µm column. The gradient LC method employs solution A and solution B as mobile phase. The solution A contains aqueous 0.1% OPA and solution B contains a mixture of water, acetonitrile (5:95 v/v). The HPLC method was developed and validated with respect to linearity, accuracy, precision, specificity and ruggedness

Inhibitory and metabolic effects of diabetes on yolk sac-derived endothelial-macrophage progenitors in postnatal murine tissues

Macrophages (MΦs) and endothelial cells (ECs) share an intimate relationship which helps mediate tissue inflammation and neovascularisation. Both cells display considerable heterogeneity, which is a product of tissue and disease context and their complex ontogeny. Converging evidence indicates developmental overlap whereby some tissue MΦs and ECs arise from a common embryonic source, namely yolk sac (YS) erythromyeloid progenitor cells. Although it is widely considered that YS-derived MΦs and ECs are maintained after birth by proliferative self-renewal, our group has recently identified YS-derived bipotent endothelial-macrophage (EndoMac) progenitors as an alternative source for their postnatal renewal in different tissues. This thesis addresses several knowledge gaps relating to EndoMac progenitors. In Chapter 3, we demonstrate that FACS-isolated and culture-derived progenitors from mouse aorta are Lin-CD45+CD11b-F4/80-Sca-1+c-Kit+ and express the receptors for fractalkine (CX3CR1) and macrophage colony-stimulating factor (CSF1R). Crucially, we also establish the bipotency of EndoMac progenitors at a single cell level. Progenitors from different tissues (aorta, skin, skeletal muscle [SkM]) exhibit important similarities, with subtle tissue-related variations in clonal renewal, angiogenic capacity and gene expression. Finally, with a view to understanding their metabolic regulation, we study the effects of high glucose on aortic progenitors and identify glucose-induced reductions in their clonogenic and angiogenic capacity, as well as their DNA integrity. Chapter 4 extends these findings by examining the effects of hyperglycaemia on skin progenitors using a streptozotocin-induced mouse model of type 1 diabetes, given that diabetes impairs skin wound healing. Exposure to high glucose in vitro and hyperglycaemia in vivo inhibits the clonal expansion, renewal, differentiation and angiogenic capacity of skin EndoMac progenitors. This is associated with reduced mitochondrial viability and metabolic function. Using lineage-mapping techniques, we reveal that diabetes attenuates the rapid burst of proliferative accumulation of YS-derived progenitors in early skin wounds. This is accompanied by blunting of the expansion of YS-derived MΦs and ECs in later stages of wound repair. Finally, we show that progenitors from non-diabetic skin can engraft, differentiate and promote wound repair when transplanted into recipient diabetic wounds, whereas these salutary properties are severely diminished for diabetic progenitors. In Chapter 5 we investigate how high glucose affects EndoMac progenitors from SkM, with focus on understanding how diabetes impairs perfusion recovery in peripheral ischaemia. High glucose and hyperglycaemia inhibit the key properties of these cells, while also dampening their metabolic activity. Lineage-tracing demonstrated that under non-diabetic conditions, hind limb ischaemia is associated with early proliferative accumulation of YS-derived progenitors, followed by sequential expansion of MΦs and ECs, such that YS is the source of up to 55% of MΦs and 80% of ECs in ischaemic SkM. This is severely reduced in diabetes. Lastly, we demonstrate that transplantation of non-diabetic SkM progenitors promotes perfusion recovery of ischaemic limbs in diabetic mice, with these cells engrafting and differentiating into both endothelial and myeloid progeny within recipient tissue. In summary, this thesis provides new insights about the properties of EndoMac progenitors across different mouse tissues, while also revealing that diabetes has striking effects on their function, metabolic activity and reparative potential. This provides a novel framework to help understand how diabetes impairs wound repair and vascularisation of ischaemic tissue.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202

FORMULATION AND EVALUATION OF FENOVERINE FLOATING TABLETS

Objective: The purpose of this research was to develop a fenoverine gastroretentive drug delivery system which, following oral administration should have the ability to enhance and prolong the period of gastric residence time (GRD) with the desired in vitro release profile. Methods: In the present study, fenoverine floating tablets were prepared using an effervescent method using sodium bicarbonate and citric acid as a gas-generating agent. The tablets were formulated using direct compression technology using xanthan gum and sodium alginate as polymers. Pre-compression powders were evaluated for angle of repose, bulk density, tapped density, Carr’s index, and Hausner’s ratio, and the prepared tablets were evaluated for weight variation, thickness, diameter, hardness, friability, drug content, floating lag time, total floating time, and in vitro dissolution studies. The formulations were optimized for the different concentrations of xanthan gum, sodium alginate, and their combinations. Results: All the prepared formulations showed well in vitro buoyancy. The tablets remained buoyant for 6–12 h. The in vitro drug-release pattern of fenoverine floating tablets was adapted to different kinetic models with the highest regression to zero-order and Korsmeyer-Peppas, and the mechanism was found to be a Fickian mechanism. Conclusion: Out of all the formulations prepared, in vitro dissolution studies of the F4 formulation were found to be maximum than other batches, which exhibited desired sustained release time followed by acceptable floating properties