Reconfigurable dual band microstrip patch antenna for software defined radio applications

In this paper, a reconfigurable microstrip patch antenna with RF pin diode switches is implemented for dual band of 2.4 GHz and 5.6 GHz Software Defined Radio (SDR) applications. For the dual band SDR system, the use of a single antenna with a wide bandwidth to cover both of the bands can be limiting for low power level signal applications due to wideband noise. A reconfigurable nested microstrip patch antenna is designed on a Rogers 5880 RT/DUROID substrate which is fed by a coaxial probe from the back side of the grounded substrate. RF switching circuitry involves four RF pin diodes at each side of the inner patch. The dual bands of 2.4 GHz and 5.6 GHz frequency operation can be simply obtained by switching the PIN diodes on and off. The antenna is well matched and achieves approximately 7 dBi simulated gain at both frequency bands. Simulation results show that the nested patch antenna is suitable for dual band SDR applications

Quantifying Losses in Power Systems Using Different Types of FACTS Controllers

This thesis discusses the placement of conventional power flow controllers (namely the Fixed series capacitor (FSC), Phase Angle Regulating Transformer (PAR)) and Flexible AC Transmission System (FACTS) devices (namely the Thyristor Controlled Series Capacitor (TCSC), the Static Synchronous Series Compensator (SSSC), the Unified Power Flow Controllers (UPFC) and the Sen Transformer (ST)) in bulk power systems to minimize transmission losses in the entire system. This firstly resolves line overloading and improves the overall voltage profile of the entire system. Secondly the transmission losses are minimized and also help in reducing the generation, which results in additional dollar savings in terms of the fuel costs. The sizes of the FACTS devices used were small in order to keep the initial installation costs low for the utility. The reduced FACTS device ratings are mentioned as a benefit, but not included in the overall loss minimization calculations. Various types of FACTS devices were modeled and placed in the power system, and the economic benefits were discussed and compared for different power flow conditions. The FSC, PAR, and TCSC are the FACTS Devices commonly used in the electric utility industry. In addition to the previous devices, the SSSC and UPFC were also modeled in the popular PSS/E and PSAT software's. The Sen Transformer was modeled using an electromagnetic transient simulation program (PSCAD/EMTDC). A line stability index was used to find the optimum location for placing the FACTS device. This thesis also provides a quantified value for the overall losses with the different FACTS devices, which is not available in the previous research literature. The Sen Transformer is a new type of a FACTS device that was developed by a former Westinghouse engineer, Dr. Kalyan Sen in 2003. It is based on the same operating principle as a UPFC (i.e. provides independent active and reactive power control) but uses the proven transformer technology instead. The benefit of the SEN transformer is that it would cost approximately only 30% of the UPFC cost. This thesis studies the Sen Transformer for loss minimization. Since the Sen technology uses a mature transformer technology, its maintenance costs are going to be less and therefore the utilities would be more comfortable using such a device instead of UPFC. A 12 bus test system proposed by FACTS modeling working group was used for validating and testing the FACTS devices in this thesis. This test system is a composite model of Manitoba Hydro, North Dakota, Minnesota, and Chicago area subsystems. This test platform manifests number of operating problems, which the electric utilities typically face. This system has been used for congestion management, voltage support and stability improvement studies with the FACTS devices. The results show that compensating a short transmission line in this system is more effective in minimizing the overall losses and improving the voltage profile compared to a typical approach of compensating long lines. The results also show that the UPFC and Sen Transformer are the most effective in minimizing the overall losses with the Sen Transformer being the most cost effective solution

Petroleum Degradation: Promising Biotechnological Tools for Bioremediation

One of the most common chemicals involved in the soil contamination or soil pollution is petroleum hydrocarbons (PHs). As we know that PH-contaminated soil affects human health directly, such as (i) contact with soil, (ii) via inhalation of vaporized contaminants, and (iii) infiltration of soil contamination into groundwater aquifers used for human consumption. Microbiological processes play an important role in the removal of PHs and take advantage of the catabolic versatility of these organisms to degrade such compounds either partially or completely (mineralization). Thus, the present chapter moves around the relationship of microorganisms with PHs. Based on this concept, this chapter has been designed to address the following relevant issues: How to isolate PH-degrading microorganisms by co-enrichment and optimized enrichment methods? How to study the microbial community structure by high-throughput sequencing method? What are the metabolic versatilities of microorganisms for degrading PHs? How to treat the environmental problems through biological means? What are the available ecotoxicity studies for the analysis of residual PHs after the microbiological treatment at the PHs-contaminated sites? Thus, the aim of this chapter is to explain the importance of microorganisms in cleaning the oil-contaminated environments

DEVELOPMENT OF ZOLMITRIPTAN MOUTH DISSOLVING FILMS: FORMULATION VARIABLES, MECHANICAL PROPERTIES, AND IN VITRO DRUG RELEASE STUDIES

Objective: The objective of the present investigation is to prepare zolmitriptan (ZOL) mouth dissolving films (MDFs) and to investigate the influence of formulation variables on physicomechanical, chemical, and drug release properties of the prepared MDFs. Methods: The MDFs were prepared by solvent casting technique using wet film applicator. The impact of hydroxypropyl methylcellulose of different viscosity grades (hydroxy propyl methyl cellulose [HPMC] E3, E5, and E15), plasticizers (glycerol and polyethylene glycol [PEG]-400), and solubilizing agents (polyvinyl pyrrolidone [PVP K30] and sodium lauryl sulfate [SLS]) on physicomechanical, chemical, and drug release properties were evaluated. The MDFs were also characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffractometry studies. Results: The MDFs prepared were transparent and smooth and showed no recrystallization. The tensile strength of the MDFs increased significantly with an increase in polymer viscosities, and about a 2.63-fold increase in tensile strength was observed for HPMC E15 MDFs compared to E3, whereas an increase in film thickness resulted in brittle MDFs with low tensile strength. Similar results were observed with percent elongation and folding endurance of the MDFs. In vitro, drug release studies indicate that higher film thickness and polymer viscosities delayed the MDF disintegration and, in turn, the ZOL release. Addition of PVP K30 and SLS to HPMC E3 formulations resulted in 1.66- and 1.53-fold increase in ZOL release rates. Conclusion: Overall, F7 formulation showed quicker disintegration (within 11 s) and ZOL release rates (within 180 s) along with good physicomechanical properties. These results indicated that the disintegration and drug release of ZOL can be enhanced to a greater extent by optimizing formulation variables in MDFs

Protective Conversion Coating on Mixed-Metal Substrates and Methods Thereof

Mixed-metal automotive vehicle bodies-in-white comprising ferrous metal surfaces, zinc surfaces, aluminum alloy surfaces, and magnesium alloy surfaces are cleaned and immersed in an aqueous bath comprising an adhesion promoter and an aqueous electrocoat bath (the adhesion promoter may be in the electrocoat bath. The adhesion promoter, which may be a cerium salt, is selected to react with each metal in the body surfaces to form an oxide layer that provides corrosion resistance for the surface and adherence for the deposited polymeric paint coating. The body is cathodic in the electrocoat deposition

Development of Capecitabine Floating Tablet Dosage Forms for Treating Stomach Cancer

Objective: In the present research work, oral gastro retentive dosage forms (GRDFs) of capecitabine (CPC) were formulated using floating concept. Methods: GRDFs were formulated using hydroxypropyl methyl cellulose (HPMC K4M and K15M) as drug release retardant, sodium bicarbonate (NaHCO3) and calcium carbonate (CaCO3) as gas generating agents, and micro crystalline cellulose (MCC), dicalcium phosphate (DCP), spray dried lactose (SDL), and pre gelatinized starch (PGS) as fillers. The tablets were prepared by direct compression method and evaluated for various parameters. The GRDFs were also characterized by Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Results and Discussion: All the formulations were subjected for pre and post compression parameters, shows all the data within the limits. The lag times of GRDFs has decreased significantly for formulations containing calcium carbonate when compared to sodium bicarbonate as gas generating agent. In vitro drug release studies indicate that higher polymer concentration delayed the CPC release, and the sustaining effect was in the order K4M > K15M > LVCR 100. Addition of MCC, DCP, SDL, and PGS as fillers further affected the lag time and in turn the CPC release rates. Conclusion: The formulation (F9) containing 10%w/w HPMC K4M as the release retardant, microcrystalline cellulose as filler and 20%w/w CaCO3 as gas generating agent fulfilled regulatory requirements in terms of percent drug release at the end of 24h. Keywords: Capecitabine, Gastro retentive floating tablets, floating drug delivery systems, FTIR, DSC

Dancing Between Success and Failure: Edit-level Simplification Evaluation using SALSA

Large language models (e.g., GPT-4) are uniquely capable of producing highly rated text simplification, yet current human evaluation methods fail to provide a clear understanding of systems' specific strengths and weaknesses. To address this limitation, we introduce SALSA, an edit-based human annotation framework that enables holistic and fine-grained text simplification evaluation. We develop twenty one linguistically grounded edit types, covering the full spectrum of success and failure across dimensions of conceptual, syntactic and lexical simplicity. Using SALSA, we collect 19K edit annotations on 840 simplifications, revealing discrepancies in the distribution of simplification strategies performed by fine-tuned models, prompted LLMs and humans, and find GPT-3.5 performs more quality edits than humans, but still exhibits frequent errors. Using our fine-grained annotations, we develop LENS-SALSA, a reference-free automatic simplification metric, trained to predict sentence- and word-level quality simultaneously. Additionally, we introduce word-level quality estimation for simplification and report promising baseline results. Our data, new metric, and annotation toolkit are available at https://salsa-eval.com.Comment: Accepted to EMNLP 202