Modeling of non-uniform hydrodynamics and catalytic reaction in a solids-laden riser

The riser reactors are widely used in a variety of industrial applications such as polymerization, coal combustion and petroleum refinery because of the strong mixing of gas and solids that yields high heat and mass transfer rates, and reaction rates. In a Fluid Catalytic Cracking (FCC) process, the performance of riser reactor is strongly dependent on the interaction between the fluid and catalysts, since the reaction takes place on the active surface of the catalysts. This is why, the local coupling between hydrodynamics and reaction kinetics is critical to the development of riser reaction models. The local gas-solids flow structure in riser reactors is highly heterogeneous both in axial and radial direction with back-mixing of catalyst. The radial non-uniform gas-solid flow structure is presented as core-annulus regime, with up-flow of dilute suspension of fresh catalyst and hydrocarbon vapor in the core regime, which is surrounded by dense down-flow of deactivated catalyst in the wall regime. As a result, the reaction characteristics in core and wall regions are strikingly different. The performance of the riser reactor is also strongly dependent on the vaporization and reaction characteristics in the feed injection regime of the riser reactors. From the modeling point of view, to predict the reaction characteristics in riser reactors, there is a need to develop hydrodynamics model, which can predicts both axial and radial nonuniform distribution of hydrocarbon vapor and catalyst and back-mixing of catalyst. There is also need for reasonable description of mechanistic coupling between nonuniform flow hydrodynamics and the cracking kinetics. This dissertation is aimed to develop the mechanistic model for nonuniform hydrodynamics and catalytic reactions in a FCC riser reactor. A mechanistic model for multiphase flow interactions, vaporization of droplets and reactions in the feed injection regime is developed for to decide proper input boundary conditions for FCC riser reaction models. The dissertation is divided into the three major parts: 1) development of governing mechanisms and modeling of the axial and radial nonuniform distribution of the gas-solids transport properties in riser reactors 2) development of mechanistic model that gives a quantitative understanding of the interplay of three phase flow hydrodynamics, heat/mass transfer, and cracking reactions in the feed injection regime of a riser reactor 3) modeling of nonuniform hydrodynamics coupled reaction kinetics in the core and wall regime of the riser reactors. For the modeling of the axial nonuniform distribution of gas-solids transport properties, a new controlling mechanism in terms of impact of pressure gradient along the riser on the particles transport is introduced. A correlation for inter-particle collision force is proposed which can be used for any operation conditions of riser, riser geometry and particle types. For simultaneous modeling of axial and radial nonuniform distribution of the gas-solids phase transport properties, a continuous modeling approach is used. In this dissertation, governing mechanisms for radial nonuniform distribution of gas-solids phase is proposed based on which a mechanistic model for radial nonuniform distribution of the gas and solid phase transport properties is proposed. With the proposed model for radial nonuniform phase distribution, the continuous model can successfully predicts both axial and radial nonuniform distribution of phase transport properties. As the performance of the riser reactor is strongly influence by the vaporization and reactions in the feed injection regime, in this dissertation, a detailed mechanistic model for the multiphase flow hydrodynamics, vaporization and reaction characteristics in feed injection regime is established. To simulate the conditions of industrial riser reactor, the four nozzle spray jets were used, while overlapping of the spray jets is also considered. Finally, in this dissertation, a modeling concept for the reactions in the core and wall regime of the riser reactor is explored. The proposed modeling concept takes into the account very important missed out physics such as, non-thermal equilibrium between the hydrocarbon vapor and the feed, back mixing and recirculation of the deactivated catalyst, activity of catalyst in core and wall regime, and coupling between the flow hydrodynamics and reaction kinetics

A SWOT Analysis Of The Use Of Social Media Networking Sites In Medical Colleges In Ahmedabad City During The Covid-19 Pandemic Situation: In Reference To The Library

This survey is concerned with trying to measure the SWOT analysis of the role of libraries in the use of social media networking sites on health educational performance during the Covid-19 pandemic situation in medical colleges providing health education in Ahmedabad, for practical reasons, the SWOT analysis was conducted to collect data on that use. To conduct a SWOT analysis to find out the challenges regarding the use of social media networking sites in the context of libraries of social educational networking sites of medical academic libraries using Google form structured questionnaire and personal interview. Keeping in mind the main approach of this case study, a SWOT analysis of the use of social media networking sites on the academic performance of library users of colleges of health sciences during the Covid-19 pandemic situation was conducted. There will be a strategic plan to increase the use of social media and its benefits by evaluating the results of the SWOT analysis. The authors present the results of the study in the form of practical recommendations for short-term and long-term implementation. Future research will provide the most beneficial for libraries on social media and related strategies and may include follow-up studies in academic libraries using the SWOT Framework tool method. In addition, comparing the results of this study with similar studies in other libraries may form a model for other libraries that may attempt to increase their capacity and knowledge through the effective use of social media. The present study attempts to plan a strategy for libraries through SWOT analysis to establish a unique distinction that highlights their strengths and challenges

Molecular characterization of Indian potato (Solanum tuberosum L.) varieties for cold-induced sweetening using SSR markers

Cold-induced sweetening developed during storage of potatoes (Solanum tuberosum L.) at low temperature is a crucial factor influencing the processing quality of potato tubers and remains one of the principal concerns of potato processing industry. Developing CIS-resistant genotypes is the most effective method to cope with this stress. In this study, the genetic diversity of 11 Indian potato varieties with different reactions to CIS was assessed using 10 SSR primers. The primers detected a total of 42 alleles arranged in 44 different configurations, among which 37 alleles (88%) were polymorphic. The polymorphic information content (PIC) value of the SSR locus ranged from 0.473 to 0.787 thus indicating a high utility of these markers for study of genetic diversity in potato. A number of polymorphic fragments appeared to be specific to a given sugar-forming group. Primer Sti007 generated one fragment Sti007131bp present only in all the high sugar-forming varieties. The dendrogram derived from Dice’s similarity coefficients among the 11 varieties could partially but efficiently differentiate close parents and sugar-forming groups among the varieties. These findings demonstrate the effectiveness of SSR markers to assess the genetic variation among potato cultivars in order to develop molecular markers associated with CIS to improve potato breeding programs

Design of a face recognition system using incremental principal component and independent component analysis (IPCA-ICA) methods

In this study, a fast incremental principal non-Gaussian directions analysis algorithm, called IPCA-ICA, is introduced. Two major techniques are used sequentially in a real-time fashion in order to obtain the most efficient and independent components that describe a whole set of human faces database. This procedure is done by merging the runs of two algorithms based on principal component analysis (PCA) and independent component analysis (ICA) running sequentially. The first technique is called incremental principal component analysis (IPCA) which is an incremental version of the popular unsupervised principal component technique. The traditional PCA algorithm computes eigenvectors and eigenvalues for a sample covariance matrix derived from a well-known given image data matrix, by solving an eigenvalue system problem. The second technique is called independent component analysis (ICA). It is used to estimate the independent characterization of human faces

Innovative Digital Marketing Strategies of Academic Library Services in Global Era

This research study describes and scrutinizes the importance of digital marketing in academic libraries. Now a day's libraries are needed to escalate their presence in the digital environment and librarians and users need to explore effective digital campaigning and promotional activities for closer to the user community for better services and make aware of the digital marketing services and resources of an academic library. Adoptive new technologies in library users are made them more techno-savvy. This study explores various innovative tools, techniques, and models for digital marketing strategy in academic library services. Academic libraries are presently experiencing variations in the innovative information era, due to quickly varying media technologies, increasing users' preferences and opportunities, rivalry from other information providers such as the internet, and dwindling library budgets. These needs of academic library users influence digital marketing approaches to strategically reorient themselves and library services as information superhighways that individuals cannot do without. The results revealed that user survey studies, e-resources, e-database, digital library services, interlibrary loan services, social media platforms, and improved burrowing privileges were prevalent marketing strategies used by faculties and students. Unstable digitization, Internet, networking, multimedia, and satellite connectivity, and inadequate funding were identified as major challenges to effective digital marketing of academic library services in the global era

Liquidity analysis of selected logistic and transport companies of India

Liquidity Management is gaining the serious attention in all over the world because of the current position of financial disorder and the business environment in the whole world economy. The promoters and managers are hired by the companies to make the suitable strategy for maintain the liquidity and increase the profitability position of the business. Liquidity is thought to maintain as well as it is the paying capacity of the business. It shows the ability of the business to survive. In this paper the comparative analysis for the liquidity position of 5 Transport and Logistic companies was done. The study covers the period of 10 years from 2010-11 to 2019-20. For this study the secondary data is used. The mean, standard deviation, coefficient of variation, ratio analysis and the ANOVA test techniques have been applied for analysing the data. This study may be the retiring plan to determine the liquidity management of the Transport and Logistic companies

Liquidity Analysis of Selected Logistic and Transport Companies of India

Liquidity Management is gaining the serious attention in all over the world because of the current position of financial disorder and the business environment in the whole world economy. The promoters and managers are hired by the companies to make the suitable strategy for maintain the liquidity and increase the profitability position of the business. Liquidity is thought to maintain as well as it is the paying capacity of the business. It shows the ability of the business to survive. In this paper the comparative analysis for the liquidity position of 5 Transport and Logistic companies was done. The study covers the period of 10 years from 2010-11 to 2019-20. For this study the secondary data is used. The mean, standard deviation, coefficient of variation, ratio analysis and the ANOVA test techniques have been applied for analysing the data. This study may be the retiring plan to determine the liquidity management of the Transport and Logistic companies

Double whammy- acute splenic sequestration crisis in patient with aplastic crisis due to acute parvovirus infection

Splenic dysfunction is a major feature of sickle cell disease (SCD) and can manifest as acute splenic sequestration crisis (ASSC), which is the earliest life-threatening complication seen in patients with SCD. Aplastic crisis is another potentially deadly complication of sickle cell disease that develops when erythrocyte production temporarily drops. Infection with parvovirus B-19 frequently causes aplastic crises. These two complications are known to be mutually exclusive due to their classic presentation signs and symptoms but there have been few cases where a patient can have concomitant presentation of both phenomena, which can result in a fatal outcome. These few cases force us to rethink the etiology and subsequent management guidelines of these complications. We present to you a case of an unfortunate 23-year-old female who had both complications occurring at the same time, resulting in death

Sarcoid-Like Mediastinal Lymphadenopathy in Gynecologic Malignancy

Noncaseating granulomas are seen surrounding tumors with varying frequency, possibly as part of an immune response to tumor cells. However, data about the association of sarcoid with gynecologic malignancy is sparse. We performed a search of our institutional database for all EBUS-TBNA biopsies conducted within the past five years that revealed granulomatous inflammation. All adult female patients with a history of gynecologic malignancy were included. Patients with a history of sarcoidosis or fungal or mycobacterial infection were excluded. All patients with evidence of malignant cells on TBNA specimen were excluded. Our results revealed 65 patients with histologic diagnosis of a noncaseating granuloma on EBUS-TBNA. Five patients (7.69%) had a history of gynecologic malignancy. Two patients had evidence of PET-positive nodes on surveillance scans, which led directly to the examination. Our findings suggest that distant malignancies may cause granulomatous lymphadenitis, through yet undefined mechanisms. As such, patients with evidence of mediastinal lymphadenopathy could benefit from routine sampling and histologic examination to define the pathology in the correct clinical context

Differentiating between various pathologies showing ring enhancement on MRI

Introduction: Ring-enhancing lesions are one of the most commonly encountered neuroimaging abnormalities visualized on MRI. The most common etiologies causing ring enhancing lesion include tuberculomas, neurocysticercosis, abscess, infarct and demyelination disorders.Mostly the ring-enhancing lesions are located at junction of the gray and white matter but in few cases they are seen in the sub-cortical area& deep brain parenchyma.Few specific features of ring enhancing lesions seen in sequences of MRI brain coupled with clinical history helps in narrowing down our diagnosis. Material and methods: 55 patients with ring enhancing lesions on MR imaging in Dhiraj hospital were considered in our study. A detailed clinical history along with general and systemic examination, especially evaluation of neurological status was done in all the patients. Results: 55 indoor patients admitted to medical ward in Dhiraj hospital of age group 16 to 70 yearswere selected for the study. Majority were in the age group of thirty to forty five years. Headache emerged as the most common complaint that the patients presented with. Out of a total of 55, 49 patients complained of headache. Vomiting was seen in 39,Seizures was seen in 21 and episodes of loss of consciousness in 11 patients.&nbsp