197 research outputs found

    Quantification of effect of convergence in porous media flow

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    An attempt is made in this study to quantify the effect of convergence on macroscopic scale in the case of flow through porous media. Experiments are conducted separately on specially conceived parallel flow permeameter and converging flow permeameter keeping identical inlet and outlet conditions, using eight sizes of coarse granular media and water as the fluid medium. The media is sieved through sieves of different sizes to separate the crushed rock into sizes of 3.25 mm, 4.73 mm, 10.00 mm, 11.64 mm, 13.10 mm, 20.10 mm, 28.90 mm and 39.50 mm and glass spheres of 15.41 mm, 18.03 mm and 28.37 mm. As the effect of convergence is predominant in non- Darcian zones of flow, such as flow near the well, flow through rock fills, filters etc.,, the scope of the present work is restricted to flow regime with Re \u3e 10. (After Kovacs) Forchheimer’s equation ( i = aV + bV2 ) is applied to analyze the experimental data. Equations are derived for Darcy parameter (a) and Non-Darcy parameter (b) of the Forchheimer’s equation for the crushed rock and glass spheres by relating to size of the media (d) in both parallel flow condition and converging flow condition. From the results it is inferred that for a given rate of flow through a known size of aquifer having predetermined grain size, the resistance to flow is higher in the parallel flow compared to similar media conditions in converging flow configurations. A comparison is then made between the coefficients of the equation, computed for parallel and converging configurations of flow. The difference in these values is expressed in terms of a factor called ‘Integrated Convergence factor (Cfi)’. It is concluded that the convergence of stream lines of seepage flow has a clear and profound influence on the relationship between resistance and regime. In order to make the findings reliable and suitable to field applications, the derived expressions are subjected to corrections for porosity effect, wall effect and tortuosity effect. Expressions for integrated convergence factor for crushed rocks and glass spheres are Cfi = 1.095 d - 0.079 and Cfi = 0.802 d - 0.25 respectively

    Development of Meshfree method for Certain Engineering Analysis Problem

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    This study presents a numerical technique that enables exact treatment of all boundary conditions including those that are given on the interface boundary of two distinct media. This interface boundary conditions for Poisson equation are formulated as equality of the physical field and fluxes across the interface boundary. In this work first, the range of physical and geometric parameters which allow the applicability of the meshfree method with distance fields are tested and compared with analytical solution. Second, it investigates how the solution error depends on the ratio of B-spline support and thickness of the interface layer. Further, this study also concentrates on developing improved computational tools like 1D integration and modification of distance fields for analysis of diffusion concentration in heterogeneous material with high contrast of physical and geometrical properties. These improved computational tools for meshfree method with distance fields improve the accuracy of solution and decreases the computational time. Finally, these improved tools are used to solve a 2D problem for analysis of diffusion concentration and the results are compared to FEM solution to show that the improved tools yield computationally better results

    FORMULATION AND IN VITRO–IN VIVO PHARMACOKINETIC EVALUATION OF CARDIOVASCULAR DRUG-LOADED PULSATILE DRUG DELIVERY SYSTEMS

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    Objective: This study is to formulate Nebivolol into a Pulsatile liquid, solid composite compression coated tablet, which will delay the release of the drug in early morning hypertension conditions. Methods: The liquid, solid composite tablet was formulated and compressed with the ethylcellulose coating polymer. The percent in vitro drug release of the liquid solid composite compressed tablet was tested. Based on disintegration time and wetting time, the LCS2, LCS3, LSC6, LCS7 and LCS12 formulations were found to be the optimized solid-liquid compacts fast-dissolving core tablet formulations, which may be excellent candidates for further coating with polymer to transfer into press coated pulsatile tablet formulations. Coating the core tablet with varying ethyl cellulose concentrations resulted in five different formulations of the pulsatile press-coated tablet (CT1, CT2, CT3, CT4, CT5). In vitro drug release, in vitro release, kinetic studies, in vivo pharmacokinetic and stability tests were all performed for the prepared pulsatile press coated tablet. Results: CT3 tablets are coated with ethyl cellulose polymer, which shows maximum controlled drug release from the core tablet i.e. 96.34±1.2% at 8th h. It shows there was an efficient delay in drug release form core tablet i.e. up to 3 h, followed by the maximum amount of drug release of 96.34±2.4 at 8h. Which shows the core drug will be more efficiently protected from the gastric acid environment 1.2 pH, duodenal environment 4.0 pH and release drug only in the small intestine. Conclusion: According to the findings, CT3 Pulsatile press-coated tablet increased the bioavailability of Nebivolol by 3.11 percent

    Unstable distal radius fractures fixation with a 2.4 mm volar variable-angle locking plate: radiological and functional assessment

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    Background: The main objective of this observational study was to evaluate the functional and radiological outcome of variable angle volar plates in intra-articular distal end radius fractures. Methods: Patients with distal end radius fractures (AO type 3C) treated operatively between Jan 2020 and Dec 2020 and then followed up for at least 12 months. A total of 32 patients (11 men and 21 women) with a mean age of 51.9 years were included in the study. The functional outcome was assessed by using modified Mayo wrist score (MMWS), disabilities of the arm, shoulder, and hand (DASH) score, wrist range of motion (ROM) and grip strength relative to the uninjured side and radiological assessment of radial height, volar tilt, and radial inclination. Results: MMWS and DASH scores improved postoperatively over time. Signs of radiographic union started around 12 weeks after surgery. The most common complication observed was finger and wrist stiffness, which was resolved with active wrist and finger movements. Non-union or hardware-related complications/ late complications such as tendon irritation/attrition were not observed with variable angle volar locking plates. Conclusions: Distal end radius fracture fixation with variable angle plate gives favourable radiological and clinical outcomes. These results can be owed to features such as low profile, variable locking, anatomical design and implant biomechanics. The surgeon determined angulation of the distal row of screw fixation may decrease the incidence of joint penetration and improve fixation of radial styloid and lunate facet stability

    A critical review on computer vision and artificial intelligence in food industry

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    Emerging technologies such as computer vision and Artificial Intelligence (AI) are estimated to leverage the accessibility of big data for active training and yielding operational real time smart machines and predictable models. This phenomenon of applying vision and learning methods for the improvement of food industry is termed as computer vision and AI driven food industry. This review contributes to provide an insight into state-of-the-art AI and computer vision technologies that can assist farmers in agriculture and food processing. This paper investigates various scenarios and use cases of machine learning, machine vision and deep learning in global perspective with the lens of sustainability. It explains the increasing demand towards the AgTech industry using computer vision and AI which might be a path towards sustainable food production to feed the future. Also, this review tosses some implications regarding challenges and recommendations in inclusion of technologies in real time farming, substantial global policies and investments. Finally, the paper discusses the possibility of using Fourth Industrial Revolution [4.0 IR] technologies such as deep learning and computer vision robotics as a key for sustainable food production

    A study on the clinical manifestations and the incidence of benign and malignant tumors in a solitary thyroid nodule

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    Tumors are either benign or malignant. The thyroid nodule, which is usually a clinical manifestation of most of the thyroid disorders, is one among them which has been the subject of controversies with divergent opinions and views. Clinical presentation of thyroid nodules varies widely ranging from solitary nodules to benign and malignant tumors. Thyroid nodules accounts up to 8% of the adult population having palpable nodules. However studies on its incidence in the population residing near seacoast are limited. Hence, the present study is carried in an aim to evaluate the clinico-pathological correlation of solitary thyroid nodule and the incidence of malignancy in the population residing at sea coast. The study is conducted in the Narayana Medical College & Hospital (NMCH), which is situated within 10-15 km radius of the seacoast in Nellore district of Andhra Pradesh, India. In this study, 73 subjects were selected who presented with thyroid swelling which was clinically confirmed as solitary thyroid nodule. Out of 73 cases, 12 cases (16.5%) were found to have malignant lesions with remaining 61 cases (83.5%) being benign lesions. The incidence of malignancy among solitary thyroid nodule subjects is up to 16.5% in the population residing near seacoast. Thus the present study warrants people to consult surgeons for early diagnosis and adequate treatment without being passive as most of these swellings are asymptomatic for long duration

    Detection and Characterization of Prevotella Intermedia and Its In Vitro Susceptibility to Selected Antimicrobial Agents in Chronic Periodontitis and Acute Myocardial Infarction

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    Background: Periodontal disease has been reported to play a causative role in acute myocardial infarction (AMI), which may add to the various risk factors associated with coronary heart disease. The objective of the present study was to investigate the presence of Prevotella intermedia – an established periodontal pathogen – in subgingival plaque samples of chronic periodontitis and AMI patients in order to identify a possible association, and to evaluate the susceptibility of Prevotella intermedia to nine antimicrobial agents. Methods: After undergoing screening for eligibility, a total of 50 subjects were included in the present study. Twenty patients were diagnosed with AMI and generalized chronic periodontitis (Group I), 20 patients were diagnosed with only AMI (Group II), and 10 subjects were healthy controls (Group III). The isolated Prevotella intermedia strains were tested for susceptibility to bacitracin, chloramphenicol, penicillin G, polymyxin, gentamycin, neomycin, tetracycline, cefotaxime, and cefoxitin using an antibiotic zonescale to determine minimum inhibitory concentrations (MICs). Results: Periodontal pathogens were identified by phenotypic and enzymatic methods. The mean bacterial load of Prevotella intermedia species was higher in Group I compared to Group II and Group III. It was also found that pencillin G, gentamycin, neomycin, tetracycline, cefotaxime, and cefoxitin inhibited 90% of Prevotella intermedia, whereas bacitracin, chloramphenicol, and polymyxin inhibited 80% of Prevotella intermedia. Thus, only 10% of Prevotella intermedia were resistant to these antibiotics. Conclusion: The present study confirms that Prevotella intermedia is associated with chronic periodontitis and AMI

    Synthesis and bioactivity of phosphorylated derivatives of stavudine

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    Novel phosphorylated derivatives of stavudine were synthesized by the reaction of bis(2-chloroethyl)phosphoramidic dichloride/4-nitrophenyl phosphorodichloridate with various cyclic amines and amino acid esters in the presence of triethylamine in dry tetrahydrofuran through the corresponding monochloride intermediates 2a-l. Further reaction of the intermediates 2a-l with stavudine in tetrahydrofuran and pyridine in the presence of triethylamine formed the title compounds 4a-l. Their structures were characterized by IR,   1H-, 13C-, 31P-NMR and mass spectral data analyses. They exhibited good antibacterial and antioxidant activities. Their bioactivity was greatly influenced by the different groups present at the phosphorus

    Surface Thermo-Dynamic Characterization of Poly (Vinylidene Chloride-Co-Acrylonitrile) (P(VDC-co-AN)) Using Inverse-Gas Chromatography and Investigation of Visual Traits Using Computer Vision Image Processing Algorithms

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    The Inverse Gas Chromatography (IGC) technique has been employed for the surface thermo-dynamic characterization of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN)) in its pure form. IGC attributes, such as London dispersive surface energy, Gibbs free energy, and Guttman Lewis acid-base parameters were analyzed for the polymer (P(VDC-co-AN)). The London dispersive surface free energy (γ L S ) was calculated using the Schultz and Dorris–Gray method. The maximum surface energy value of (P(VDC-co-AN )) is found to be 29.93 mJ·m−2 and 24.15 mJ·m−2 in both methods respectively. In our analysis, it is observed that the γ L S values decline linearly with an increase in temperature. The Guttman–Lewis acid-base parameter Ka, Kb values were estimated to be 0.13 and 0.49. Additionally, the surface character S value and the correlation coefficient were estimated to be 3.77 and 0.98 respectively. After the thermo-dynamic surface characterization, the (P(VDC-co-AN)) polymer overall surface character is found to be basic. The substantial results revealed that the (P(VDC-co-AN)) polymer surface contains more basic sites than acidic sites and, hence, can closely associate in acidic media. Additionally, visual traits of the polymer (P(VDC-co-AN)) were investigated by employing Computer Vision and Image Processing (CVIP) techniques on Scanning Electron Microscopy (SEM) images captured at resolutions ×50, ×200 and ×500. Several visual traits, such as intricate patterns, surface morphology, texture/roughness, particle area distribution (DA), directionality (DP), mean average particle area (µavg) and mean average particle standard deviation (σavg), were investigated on the polymer’s purest form. This collective study facilitates the researches to explore the pure form of the polymer Poly(vinylidene chloride-co-acrylonitrile) (P(VDC-co-AN )) in both chemical and visual perspective

    Meeting IMT 2030 Performance Targets: The Potential of OTFDM Waveform and Structural MIMO Technologies

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    The white paper focuses on several candidate technologies that could play a crucial role in the development of 6G systems. Two of the key technologies explored in detail are Orthogonal Time Frequency Division Multiplexing (OTFDM) waveform and Structural MIMO (S-MIMO)
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