A quasi-steady modeling approach of a heat pump water heater system with experimental validation and analysis

In a heat pump water heater system, the dynamic interdependence between the vapor compression system and the water in the storage tank poses a modeling challenge for steady-state refrigeration system models. The aim of this project is to develop a model and methodology for coupling steady-state vapor compression system modeling with a dynamic condenser cooling medium. Consequently, a quasi-steady transient model is developed involving a steady-state vapor compression system model in Engineering Equation Solver (EES) and a computational fluid dynamics (CFD) model in ANSYS Fluent for simulating the heat transfer and fluid dynamics in the water tank. The respective models are connected at the interface of the tank wall and the water in the storage tank. The linked modeling process, described in the manuscript, involves iteration between the CFD model of the water tank and the vapor compression system model around a quasi-steady warm up of a heat pump water heating system. The model is developed around a physical heat pump water heater system. An experimental investigation is also conducted to aid with model validation

A dynamical model of a GRID market

We discuss potential market mechanisms for the GRID. A complete dynamical model of a GRID market is defined with three types of agents. Providers, middlemen and users exchange universal GRID computing units (GCUs) at varying prices. Providers and middlemen have strategies aimed at maximizing profit while users are 'satisficing' agents, and only change their behavior if the service they receive is sufficiently poor or overpriced. Preliminary results from a multi-agent numerical simulation of the market model shows that the distribution of price changes has a power law tail.Comment: 4 pages, 3 figure

Linked Modelling of Heat Pump Water Heater Vapor Compression System and Water Tank

A computational fluid dynamics (CFD) model is developed in ANSYS Fluent for simulating the heat transfer and fluid dynamics in the water tank of a US-type residential heat pump water heating unit that utilizes a wrap-around coil condenser that transfers heat from refrigerant to water through the tank wall. The linked modelling process involves iteration between the CFD model of the water tank and a vapor compression system model (using EES) in describing quasi-steady warm up of a heat pump water heating system. The models are connected via temperatures and heat transfer at the tank wall. The models and the linking procedure are validated experimentally based upon a quasi-steady approach. A wholesome understanding of heat distribution and fluid dynamics in the water tank can enable design optimizations of coil geometry, placement (pitch), etc. Performance is influenced by profiles of water temperature in the tank and refrigerant in the condenser, assuming constant pressure drop, during various warm-up experiments

Online parameter estimation applied to mixed conduction/radiation

The conventional method of thermal modeling of space payloads is expensive and cumbersome. Radiation plays an important part in the thermal modeling of space payloads because of the presence of vacuum and deep space viewing. This induces strong nonlinearities into the thermal modeling process. There is a need for extensive correlation between the model and test data. This thesis presents Online Parameter Estimation as an approach to automate the thermal modeling process. The extended Kalman fillter (EKF) is the most widely used parameter estimation algorithm for nonlinear models. The unscented Kalman filter (UKF) is a new and more accurate technique for parameter estimation. These parameter estimation techniques have been evaluated with respect to data from ground tests conducted on an experimental space payload

CORRELATION OF TWO PYRAZOLINE MOIETY IN A SINGLE MOLECULE VIA N-LINKAGE CONTAINING FLUORINE ATOM AS A SUBSTITUENT AND THEIR BIOLOGICAL SIGNIFICANCE

Objective: The aim of the present invention is to synthesize and find out the biological importance of the series of the designed pyrazoline compounds. Methods: A series of 3-[3'-(2â€,4â€-dichloro-5â€-fluorophenyl)-5'-(2â€-furyl)-4', 5'-dihydro-1H-pyrazol-1'-yl]-5-substituted phenyl-2-pyrazolines (2a-j) and 1-Nitroso-3-[3'-(2â€,4â€-dichloro-5â€-fluorophenyl)-5'-(2â€-furyl)-4', 5'-dihydro-1H-pyrazol-1'-yl]-5-substituted phenyl-2-pyrazolines (3a-j) were prepared in moderate yields. The structures of both pyrazoline and N-nitroso pyrazoline derivatives have been characterized on the basis of physical properties of the molecule and satisfactory spectral (IR, 1H NMR) data. The antimicrobial activity of the compounds against some Gram (+) and Gram (–) bacteria is reported. Results: The Moderate yield of the proposed compounds was obtained. Spectral analysis showed the structural confirmation of the synthesized compounds. Some of the compounds showed lower to moderate level of drug-like properties. Conclusion: From the results of spectral data and microbial activity it has been concluded that the compounds were found to exhibit some functional lead properties; hence these compounds are worth to be considered as potential lead molecules for further study

Prospective study on outcome of post-partum intrauterine contraceptive device insertion at tertiary level rural health institute of Gujarat, India

Background: This study was conducted to evaluate the acceptance, safety, efficacy, complications and expulsion rate of post-partum intrauterine contraceptive device (PPIUCD) insertion among post-partum pregnant women in a rural tertiary care center. Objective of this study was assessment of the efficacy and safety of post-partum IUCD insertion. Comparing the complications and client satisfaction in both groups (intra caesarean insertion versus vaginal route of insertion).Methods: This is a prospective study conducted at one of the rural tertiary care teaching institution. A total of 150 patients with caesarean or vaginal deliveries had PPIUCD insertions and they were followed up for a period of one year. The outcome measures analyzed were menstrual irregularities, vaginal discharge, pelvic infection and perforation and efficacy measures - failure, expulsion and removal. Data are expressed in frequency and percentage. Chi square test was used for comparison and P value <0.05 was considered significant.Results: The study shows that PPIUCD is an effective intervention in both caesarean and vaginal delivery with non-significant differences in safety and efficacy depending on the route of insertion. There was no case of perforation and no significant risk of infection in either caesareans or delivery. Spontaneous expulsion occurred in two cases inserted by vaginal route. Missing string incidence is high in the caesarean group compared to vaginal insertion.Conclusions: PPIUCD is a safe, effective and long term reversible method of contraception and should be encouraged by public awareness and community acceptance

Correlation of types of diabetic retinopathy and its psychosocial impact

Background: Diabetic retinopathy affects majority (70% to 90%) of diabetic patients, causes visual impairment which leads to severe psycho-social disruption in life. Our objective was to study the patients of diabetic retinopathy, co-relate between the types of diabetic retinopathy and the extent of psychosocial impairment in these patients.Methods: Data of the diabetic patients attending the Retina Clinic of C.H. Nagri Eye Hospital, Ahmedabad was collected using a pretested questionnaire. It included ocular history, history related to diabetes, data of ocular examination and type of retinopathy (if present). For psycho-social assessment, the patients were asked to fill the validated Gujarati language version of “General Health Questionnaire -28 (GHQ 28).” Selfscoring was done ranging from 0-1-2-3 (lower to higher disability respectively). Analysis of significance was carried out by Mann-Whitney Test using statistical software.Results: Total 308 patients were studied. The subjects were divided into 3 groups: (A) Diabetes mellitus type-2 (DM-2) patients without retinopathy. (B) DM-2 patients having non-proliferative retinopathy (C) DM-2 patients having proliferative retinopathy. According to the accepted scoring pattern of GHQ-28 (cut of point 25), it was observed that 80.26% of patients having non-proliferative retinopathy in both eyes and 93.75% patients having proliferative retinopathy in both eyes were psychosocially impaired. The impairment was found to be more severe in proliferative retinopathy patients as compared to non-proliferative retinopathy patients. (p value NPDR = 35.74). It was also found that in DM-2 patients without retinopathy the average mean score was 25.22 which showed less impairment (p value <0.005).Conclusions: Patients of Diabetic Retinopathy had more psychosocial impairment which shows its significant impact on quality of life and overall health. Psychiatric counselling must be given to the impaired patients to decrease the impact of the disease on the psychosocial aspect of health. It is necessary to decrease the psychosocial suffering along with the control of disease

Evaluation of management in acute coronary syndrome and extent of adherence to standard treatment guidelines

Background: India has the highest burden of acute coronary syndrome (ACS) in the world. This research is to evaluate prescriptions pattern and extent of adherence to American College of Cardiology (ACC)\American Heart Association (AHA) guidelines in the management of ACS with patient outcome.Methods: Case record form containing patient’s demographic, clinical profile, diagnosis, prescription drugs (with dose, duration and frequency) were noted. Pharmacotherapy was compared to ACC/AHA guidelines, to evaluate adherence, guideline adherence index (GAI-5) was used for 5 major drug groups for ACS. GAI was calculated as: number of patients using the prescribed medications/number of eligible patients multiplied by 100.Results: A total of 172 patients diagnosed with ACS. 64 (37.20%) Patients with the highest preponderance to ACS belonged to 51-60 years age group with a 4.73:1 male to female ratio. ST-elevation myocardial infarction (STEMI) (44.77%) was the most common diagnosis and an average of 14.66±4.34 drugs were prescribed. Majority of the patients opted for percutaneous coronary intervention (PCI) with or without having received fibrinolytic therapy at onset. Adherence to the ACC/AHA guidelines being 93.75% and 118 prescriptions being 100% adherent to the guidelines. A positive correlation between adherence and number of drugs was statistically significant.Conclusions: The success of evidence-based medicine (EBM) was well noted with a 0% in hospital mortality rate i.e. all of the 172 patients were discharged with therapeutic success. Despite the concept of EBM and its proven effectiveness, there is a paucity of availability of such guidelines in India, so this study, a first of its kind can serve as a starting point of generating national as well as local guidelines