(R2053) Analysis of MAP/PH/1 Queueing Model Subject to Two-stage Vacation Policy with Imperfect Service, Setup Time, Breakdown, Delay Time, Phase Type Repair and Reneging Customer

In this paper, we study a continuous-time single server queueing system with an infinite system of capacity, a two-stage vacation policy with imperfect service, setup, breakdown, delay time, phase-type of repair and customer reneging. The Markovian Arrival Process is used for the arrival of a customer and the phase-type distribution is used when offering service. This encompasses the policy of two vacations: a single working vacation and multiple vacations. Using the Matrix-Analytic Method to approach the system generates an invariant probability vector for this model. Henceforth, the busy period, waiting time distribution and cost analysis are the additional findings. The indicators are secured as a result of this performance. The outcomes result of numerical order can be graphically interpreted in the form of 2D and 3D

The Land-based Diet of the Sangam People and the Development of the Culinary Hierarchy

The ancient Tamils lived with nature. They ate naturally available food and satiated their hunger. Naturally occurring foods were terrestrial foods. They ate such land-based food without any change. They were then subjected to various ripening procedures and eaten. This food culture tradition can be seen in the Sangam Songs. The food culture of the Tamils has undergone many changes and can also be regarded as a gradual development. Sangam People made a living by eating land-based food according to the situation. The study reveals the culture and the cultural attitude of consumption for the development of social civilization when one observes the movement from a naturally eaten state of uncooked food to the stage of cooking and eating food in the cooked state, by making it a mixture of food, processing and eating it

Morphological Stability of Copper Surfaces under Reducing Conditions

Though copper is a capable electrocatalyst for the CO2 reduction reaction (CO2RR), it rapidly deactivates to produce mostly hydrogen. A current hypothesis as to why this occurs is that potential-induced morphological restructuring takes place, leading to a redistribution of the facets at the interface resulting in a shift in the catalytic activity to favor the hydrogen evolution reaction over CO2RR. Here, we investigate the veracity of this hypothesis by studying the changes in the voltammetry of various copper surfaces, specifically the three principal orientations and a polycrystalline surface, after being subjected to strongly cathodic conditions. The basal planes were chosen as model catalysts, while polycrystalline copper was included as a means of investigating the overall behavior of defect-rich facets with many low coordination steps and kink sites. We found that all surfaces exhibited (perhaps surprisingly) high stability when subjected to strongly cathodic potentials in a concentrated alkaline electrolyte (10 M NaOH). Proof for morphological stability under CO2RR-representative conditions (60 min at -0.75 V in 0.5 M KHCO3) was obtained from identical location scanning electron microscopy, where the mesoscopic morphology for a nanoparticle-covered copper surface was found unchanged to within the instrument accuracy. Observed changes in voltammetry under such conditions, we found, were not indicative of a redistribution of surface sites but of electrode fouling. Besides impurities, we show that (brief) exposure to oxygen or oxidizing conditions (i.e., 1 min) leads to copper exhibiting changing morphology upon cathodic treatment which, we posit, is ultimately the reason why many groups report the evolution of copper morphology during CO2RR: accidental oxidation/reduction cycles.Catalysis and Surface Chemistr

Electrocatalysis under cover: enhanced hydrogen evolution via defective graphene-covered Pt(111)

The production of hydrogen via water electrolysis using renewable electricity is a promising carbon-neutral technology. In this contribution, we report insights into the hydrogen evolution reaction (HER) in H2SO4 on Pt(111) and graphene-covered Pt(111), in addition to the electrochemical properties of graphene overlayers. As-prepared graphene overlayers are selectively permeable to H+ ions in the electrolyte, allowing H+ ions into the confined layer between graphene and Pt(111) while excluding SO42- and other anions. We demonstrate that defects in these as-prepared graphene overlayers can be generated from oxidation at high overpotentials or reduction from the production of H-2 bubbles and postulate that HER occurs locally at only Pt(111) in the proximity of defects in graphene overlayers on asprepared G/Pt(111) electrodes, and as defects in graphene increases, more of the Pt(111) surface becomes utilized for HER. Kinetically, the addition of defective graphene overlayers can increase the geometric HER rate by up to 200%, while Tafel slopes and [H+] reaction orders remain unchanged. These results shed kinetic insight into the nature of graphene overlayers and their effect on HER catalysis and also demonstrate the promise of confinement modifications in designing catalysts with properties closer to achieving optimum rates.Catalysis and Surface Chemistr

The Inter-Relation of Objective Assessment of The Bell’s Palsy with House-Brackmann Score: A Prospective Study

Introduction: Bell’s palsy is the most common acute peripheral mononeuropathy, which leads to the partial or complete inability to voluntary movement of the facial muscles on the affected side of the face. The study aimed to evaluate the objective assessment of the Bell’s palsy with House-Brackmann score. Methods: This Observational, Prospective study was to be conducted at tertiary care hospital among from June 2022 to September 2022 on 11 patients diagnosed with Bell’s Palsy. A patient’s history includes age, sex, and clinical features. Assessments include facial nerve grading system such as House-Brackmann score, which was used to grade the facial nerve severity. Results: Out of 11 patients, 7 patients of Bell’s Palsy (63%) were reported with Grade IV of House- Brackmann score. The remaining patients were scored under Grade III and Grade V. Patients of age group from 9 to 75 were taken. Among them, age group of 9-40 years were 45% and 40- 80 years were 55%. The result shows that Grade IV is predominant over others, male and elder patients are leading over female and middle- aged patients. 63.7% patient’s clinical features were come under Grade IV of House- Brackmann score. 27.2% of patients had an increased risk of hypertension, 18.1% had Diabetes Mellitus, 18.1% had past history of CVA, 9% had past history of Seizure, and known history of Bell ’s palsy. Conclusion: Using the House-Brackmann grading system, the severity of the patient presenting with Bell’s palsy could be reliably predicted

Clean and reproducible voltammetry of copper single crystals with prominent facet-specific features using induction annealing

Although copper is widely used as an electrocatalyst for the CO2 reduction reaction, often little emphasis is placed on identifying exactly the facet distribution of the copper surface. Furthermore, because of differing surface preparation methodologies, reported characaterization voltammograms (where applicable) often vary significantly between laboratories, even for surfaces of supposedly the same orientation. In this work, we describe a surface preparation methodology involving the combination of induction annealing and well-documented electrochemical steps, by which reproducible voltammetry for copper surfaces of different orientations can be obtained. Specifically, we investigated copper surfaces of the three principal orientations: {111}, {100} and {110}, and a representative polycrystalline surface. We compared these surfaces to surfaces reported in the literature prepared via either electropolishing or UHV-standard methodologies, where we find induction preparation to yield improvements in surface quality with respect to electropolished surfaces, though not quite as good as those obtained by UHV-preparation.Catalysis and Surface Chemistr

Dizaj i statistička optimizacija liposfera s glipizidom pomoću metodologije odgovora površine

A 32 factorial design was employed to produce glipizide lipospheres by the emulsification phase separation technique using paraffin wax and stearic acid as retardants. The effect of critical formulation variables, namely levels of paraffin wax (X1) and proportion of stearic acid in the wax (X2) on geometric mean diameter (dg), percent encapsulation efficiency (% EE), release at the end of 12 h (rel12) and time taken for 50% of drug release (t50), were evaluated using the F-test. Mathematical models containing only the significant terms were generated for each response parameter using the multiple linear regression analysis (MLRA) and analysis of variance (ANOVA). Both formulation variables studied exerted a significant influence (p < 0.05) on the response parameters. Numerical optimization using the desirability approach was employed to develop an optimized formulation by setting constraints on the dependent and independent variables. The experimental values of dg, % EE, rel12 and t50 values for the optimized formulation were found to be 57.54 ± 1.38 µm, 86.28 ± 1.32 %, 77.23 ± 2.78 % and 5.60 ± 0.32 h, respectively, which were in close agreement with those predicted by the mathematical models. The drug release from lipospheres followed first-order kinetics and was characterized by the Higuchi diffusion model. The optimized liposphere formulation developed was found to produce sustained anti-diabetic activity following oral administration in rats.32 faktorijalni dizajn primijenjen je za pripravu liposfera s glipizidom metodom separacije pomoću emulzija koristeći parafinski vosak i starinsku kiselinu kao tvari za usporavanje. Pomoću F-testa praćen je učinak kritičnih varijabli tijekom formuliranja, tj. količina parafinskog voska (X1) i udio stearinske kiseline (X2) na srednji promjer liposfera (dg), postotak inkapsulirane ljekovite tvari (% EE), oslobađanje ljekovite tvari nakon 12 h (rel12) te vrijeme potrebno za oslobađanje 50% ljekovite tvari (t50). Pomoću multiple linearne regresijske analize (MLRA) i analize varijabli (ANOVA) za svaki su parametar načinjeni matematički modeli koji sadrže samo značajne varijable. Proučavanje varijabli na oba načina ukazalo je na njihov značajan utjecaj (p < 0,05) na parametre liposfera. Postavljanjem ograničenja na zavisne i nezavisne varijable provedena je numerička optimizacija na principu poželjnosti. Eksperimentalne vrijednosti dg, % EE, rel12 i t50 optimiziranih formulacija bile su 57,54 ± 1,38 µm, 86,28 ± 1,32%, 77,23 ± 2,78% i 5,60 ± 0,32 h. Dobivene eksperimentalne vrijednosti iznosile su vrlo slične vrijednostima predviđenim matematičkim modelima. Oslobađanje glipizida iz liposfera slijedio je kinetiku prvog reda i okarakterizirano je Higuchijevim difuzijskim modelom. Optimizirane liposfere su nakon peroralne primjene na štakorima pokazale produljeni antidijabetički učinak

Studies on the chemical synthesis and characterization of lead oxide nanoparticles with different organic capping agents

Lead oxide (PbO) nanoparticles were chemically synthesized using Lead (II) acetate as precursor. The effects of organic capping agents such as Oleic acid, Ethylene Diamine Tetra Acetic acid (EDTA) and Cetryl Tri Methyl Butoxide (CTAB) on the size and morphology of the nanoparticles were studied. Characterization techniques such as X-ray diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Photoluminescence (PL) Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) were used to analyse the prepared nanoparticles for their physical, structural and optical properties. The characterization studies reveal that the synthesized PbO nanoparticles had well defined crystalline structure and sizes in the range of 25 nm to 36 nm for capping agents used and 40 nm for pure PbO nanoparticles

Characterization Studies on the Chemically Synthesized α and β Phase PbO Nanoparticles

Abstract: The α and β phase lead oxide (PbO) nanoparticles were synthesized by the simple chemical precipitation technique. The samples were characterized using X-ray diffraction (XRD), UV-visible (UV-vis) and photoluminescence (PL) spectroscopy. XRD analysis confirmed the tetragonal structure for the α-PbO and orthorhombic form for the β-PbO nanocrystallites with an average crystallite size of 36 and 47 nm, respectively. From the UV-Vis spectra the direct band gap energies were estimated as 3.91 eV for α-PbO and 3.85 eV for β-PbO. The PL studies revealed the blue and green emissions due to excitonic recombination and synthesis originated defects. No peaks appeared corresponding to near band edge emission. The density of defects in α-PbO was lower than that of β-PbO