Model-based Design, Operation and Control of Pressure Swing Adsorption Systems

This thesis is concerned with the design, operation and control of pressure swing adsorption (PSA) systems, employing state of the art system engineering tools. A detailed mathematical model is developed which captures the hydrodynamic, mass transfer and equilibrium effects in detail to represent the real PSA operation. The first detailed case study presented in this work deals with the design of an explicit/multi-parametric model predictive controller for the operation of a PSA system comprising four adsorbent beds undergoing nine process steps, separating 70 % H2, 30 % CH4 mixture into high purity hydrogen. The key controller objective is to fast track H2 purity to a set point value of 99.99 %, manipulating time duration of the adsorption step, under the effect of process disturbances. To perform the task, a rigorous and systematic framework is employed comprising four main steps of model development, system identification, the mp-MPC formulation, and in-silico closed loop validation, respectively. Detailed comparison studies of the derived explicit MPC controller are also performed with the conventional PID controllers, for a multitude of disturbance scenarios. Following the controller design, a detailed design and control optimization study is presented which incorporates the design, operational and control aspects of PSA operation simultaneously, with the objective of improving real time operability. This is in complete contrast to the traditional approach for the design of process systems, which employs a two step sequential method of first design and then control. A systematic and rigorous methodology is employed towards this purpose and is applied to a two-bed, six-step PSA system represented by a rigorous mathematical model, where the key optimization objective is to maximize the expected H2 recovery while achieving a closed loop product H2 purity of 99.99 %, for separating 70 % H2, 30 % CH4 feed. Furthermore, two detailed comparative studies are also conducted. In the first study, the optimal design and control configuration obtained from the simultaneous and sequential approaches are compared in detail. In the second study, an mp-MPC controller is designed to investigate any further improvements in the closed loop response of the optimal PSA system. The final area of research work is related to the development of an industrial scale, integrated PSA-membrane separation system. Here, the key objective is to enhance the overall recovery of "fuel cell ready" 99.99 % pure hydrogen, produced from the steam methane reforming route, where PSA is usually employed as the purification system. In the first stage, the stand-alone PSA and membrane configurations are optimized performing dynamic simulations on the mathematical model. During this procedure, both upstream and downstream membrane configuration are investigated in detail. For the hybrid configuration, membrane area and PSA cycle time are chosen as the key design parameters. Furthermore, life cycle analysis studies are performed on the hybrid system to evaluate its environmental impact in comparison to the stand-alone PSA system

Complementary and alternative medicine use among type 2 diabetes patients in a tertiary care hospital

Background: Complementary and alternative medicine (CAM) use is prevalent among chronic diseases like Diabetes mellitus (DM). Therefore, the aim was to study the pattern of CAM use among Type2DM in our set up.Methods: The study was done in diabetic patients attending OPD of Government medical college hospital over a period of 2 months. Patients who gave consent were subjected to a pre-structured questionnaire which consisted of two parts pertaining to socio-demographic profile and CAM usage details.Results: Out of 280 patients enrolled in the study, 110 admitted being CAM users along with conventional Anti-Diabetic treatment. The CAM users were mostly females (56.36%) and were from rural background (70.90%). CAM was prevalent in educated patients (90.90%) more than illiterates (9.09%). Ayurveda (44.54%) was the most common type of CAM used and relatives (58.18%) provided main source of CAM information. 32.72% patients thought that CAM is safe, effective (20.90%) and less costly (19.09%). Only 16.36% patients disclosed regarding their CAM usage to the attending physician while majority (83.63%) were non-revealers. The results suggest that patients should be encouraged to reveal to their physician regarding CAM as it can avoid possibility of interactions.Conclusions: CAM is prevalent in T2DM and more so in females from rural areas. Ayurveda was the most widely type of CAM used and majority of patients did not disclose to the treating physician regarding CAM usage

SECONDARY MITOCHONDRIAL DYSFUNCTION

Mitochondria are the most vital organelle in the cell because of its multitask properties. They are well known for the production of energy in the form of adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS), which involves multiple complexes and cofactors. Mitochondria in addition to ATP production, also perform other vital functions like generation of reactive oxygen species (ROS), antioxidants, apoptosis, signaling and hormone actions. Because of their multiple actions, it is quite expected that their dysfunction will result in the number of effects. Since most vital organs exclusively depend on ATP to perform their functions, therefore impediment in its supply resulting from mitochondrial dysfunction will be detrimental and have a widespread spectrum. Neurodegenerative disorders, Huntington’s disease, cardiovascular disease (CVD), epilepsy, aging, metabolic syndrome, diabetes, autism, muscular atrophy, lou gehrig’s disease, neoplasia, down syndrome are few instances where mitochondrial dysfunction is the basic cause in pathogenesis. Mitochondrial disorders are either Primary or secondary disorders. Primary mitochondrial disease or disorder (PMD) has mitochondrial or nuclear deoxyribonucleic acid (mt DNA or nDNA) mutation affecting oxidative phosphorylation (OXPHOS). While Secondary mitochondrial dysfunction (SMD) does not involve OXPHOS but is the result of mutations in non OXPHOS genes. Secondary mitochondrial dysfunction (SMD) can also be acquired secondary to adverse factors those cause oxidative stress. All this highlights the role of mitochondria and makes it a new therapeutic target in managing these disorders. The present review has briefly discussed the secondary mitochondrial dysfunctional disorders and the approach to tackle it

Evaluation of capsule labelling for its wall contents as gelatin or non gelatin

Background: Capsules are the most commonly used solid drug dosage form and are made up of gelatin or non gelatin. Currently the gelatin based capsules drug formulations are more used. However, current issue of vegetarian and non vegetarian capsules has come up due to recent Indian government initiative to promote vegetarian capsules.Methods: There were 100 capsule dosage forms were examined for the gelatin or HPMC wall contents and nature of medicine contained in capsules, whether ayurvedic or allopathic.Results: Out of 100 capsules studied 55 had gelatin wall base while 25 had HPMC and 20 capsule labels did not mention the nature of capsule wall constituent. Out of 55 gelatin capsules 30 were of allopathic while 25 capsules were of ayurvedic medicines. Among HPMC, 15 were ayurvedic while 10 allopathic. 20 capsules had no mention of its constituent and among these non labelled capsule formulations had 11 from ayurvedic and 9 from allopathic medicines.Conclusions: The current study revealed that gelatin capsules forms bulk in Indian market. Even the gelatin capsules contained ayurvedic medicines while 10% of HPMC capsules contained allopathic medicines. Non labelled capsules formed 20% of total capsules. These findings suggest wider scope for promotion of HPMC based capsules

KAP on antibiotic usage and resistance among second professional medical students

Background: Antibiotics are wonder drugs as they prevent and treat bacterial infections. However, their irrational use even by wrong prescribing behaviour of physician leads to antibiotic resistance medical students are future doctors and are provided knowledge and practice of antibiotics in treatment, and prevention of diseases in their study curriculum of second professional course mainly in chapters of pharmacology and microbiology. Therefore, the present study was to determine the second-year medical students’ knowledge, attitude and perception regarding antimicrobial use and resistance.Methods: Study was conducted on second professional undergraduate medical students from Government Medical College, Jammu. 140 students participated, and informed consent was taken prior to study. A validated questionnaire comprised of 20 questions was provided to them and responses were recorded. Questionnaire was comprised of 20 questions (13 questions attributed to knowledge of antibiotics usage and resistance, six to attitude and one question regarding perception).Results: The students showed fair knowledge about antibiotics and resistance. Percentages of fully correct answers was between 63-100% regarding knowledge of antibiotics. The attitude results revealed that self-medication by the student was observed in 67%, while 70% agreed that they had left over antibiotics at home, but only 42% committed that they take these left over antibiotics. As far as practice was concerned the maximum students consult text books as source of knowledge regarding resistance followed by Wikipedia.Conclusions: The current study observed high score of knowledge than attitude in medical students regarding antibiotic usage and resistance and increasing influence of internet like Wikipedia. This underscores the need for more effort in updating the students regarding antibiotic usage and resistance and laying more emphasis in the core curriculum of their academics

Comparative study of impact of marketing strategies of pharmaceutical houses on prescription practices of doctors rural vs urban

Background: Indian pharmaceutical market is fast going and there is a stiff competition amongst them as single product is marketed by different brand names. The pharmaceutical houses adopt different strategies to influence the physician to promote their products. These strategies are known to influence the prescription behaviour of physician, which may have variable impact among rural and urban doctors. Aim of the study was to compare the impact of marketing strategies of pharmaceutical houses on prescription practices of rural and urban doctors.Methods: The current crossover study was conducted among urban and rural doctors. A questionnaire consisting of 17 questions was presented to the doctors and their responses regarding different aspects of marketing strategies was recorded. Comparison between two groups was done using unpaired t-test.Results: Different strategies had impact on prescription pattern of doctors working in rural and urban institutions. All 17 parameters were affected similarly except e-mailing where urban doctors were more influenced (p=0.005).Conclusions: Present study indicates marketing strategies by different pharmaceutical houses do influence prescription pattern of physicians. Both urban and rural doctors were similarly affected except e- mailing which had more impact on urban doctors

A questionnaire based study to evaluate the knowledge, attitude and perception towards pharmacovigilance among doctors in rural hospital, Jammu, India

Background: Monitoring and reporting of adverse drug reactions (ADRs) is very important to minimize or prevent drug caused harm. Thus, pharmacovigilance deals with it and ensures the patient safety. However, most of pharmacovigilance centers are concentrated in the urban tertiary care hospitals and contributes the maximum reports of ADRs. Participation of the rural health workers is equally important towards the success of pharmacovigilance.Methods: The study was conducted using a pre-validated questionnaire among forty doctors in rural Sub district hospital Akhnoor, Jammu after approval of the institutional ethical committee of Government Medical Jammu. The questionnaire consisted of 16 questions (7 related to knowledge, 4 related to attitude, and 4 related to practice and one question pertained to under reporting). The responses were recorded, and data obtained was analysed and presented as number and percentage.Results: Total 66.6% doctors gave correct response regarding the definition of pharmacovigilance and purpose of pharmacovigilance was given by 76.6% of doctors. 70% agreed that ADR reporting is a professional obligation for them. 80% responded that health care professionals are responsible for reporting ADRs. 63.3% of them were aware of a pharmacovigilance programme of India. A total of 96.6% doctors agreed that reporting of ADR is necessary and 93.3% were of the view that pharmacovigilance should be taught in detail. Majority of doctors have experienced ADRs in patients and 36.6% have seen the ADR reporting form. However, only 10% have ever reported ADR to a pharmacovigilance center. No remuneration (50%), lack of time to report ADR (30%), belief that a single unreported case may not affect ADR database (10%), and difficulty to decide whether ADR has occurred or not (10%) were important causes for under reporting of ADRs.Conclusions: Current study has shown that majority of the doctors have good knowledge and attitude about pharmacovigilance. However, under reporting is still a major concern among rural doctors and efforts are needed to address this problem of under reporting by conducting CMEs on regular basis