Development and Evaluation of Automated Virtual Refrigerant Charge Sensor Training Kit

In a vapor compression system, the amount of refrigerant charge significantly affects the performance of the unit. Improperly charged systems run sub-optimally and thus result in higher operating costs due to increased energy usage. The unit can be undercharged due to a small leakage over the years. Similarly, the unit can be overcharged due to improper maintenance practices. Currently, there is no direct way to measure the amount of refrigerant in the system. In this thesis, virtual refrigerant charge sensors were developed and implemented for a rooftop unit using a previously developed approach. An open lab methodology with low cost electrical hardware was implemented for training the virtual refrigerant charge sensor which can be used as a substitute to expensive psychrometric chamber testing. The entire test methodology was automated which significantly reduced the need for human intervention. The open lab training results were validated by testing the RTU inside psychrometric chambers at different ambient conditions and charge levels. The accuracy of the virtual refrigerant charge sensor model trained using open lab methodology was within ±10% of the actual charge measurement. The concept of an automated charging kit was extended further to facilitate adding as well as removing refrigerant charge in the system. This apparatus was used to test the RTU at different charge levels in an attempt to locate an optimal operating charge for coefficient of performance as well as cooling capacity. The results indicate a relatively flat variation of COP and cooling capacity with charge around the optimal. The automated open lab training methodology can significantly lower testing costs for VRC sensor tuning as it eliminates the need for psychrometric chambers as well as human interference

Novel Ophthalmic Formulations For Improved Natamycin Delivery In Fungal Infections Of The Eye.

Natamycin (NT) is a front-line drug in the management of ocular fungal infections (OFI). An ophthalmic marketed NT suspension (Natacyn®) is currently the only FDA approved medication prescribed in the pharmacotherapy of OFI. Current NT pharmacotherapy requires frequent topical administration (every hour or 2-hours over 6-8 times in a day) due to it being instilled as eye-drops. This leads to higher precorneal losses and subsequent poor permeation and bioavailability. Therefore, in this research study, alternative ocular formulations of NT were investigated with an intent to improve precorneal retention and corneal permeation in comparison to Natacyn®. Chapter 1 discusses various aspects of NT such as its chemistry and pharmacology, antifungal spectrum and potential for development of resistance, ocular clinical evaluations, and specifics on Natacyn® to obtain a perspective of NT use in OFI. Chapter 2 reports the preparation and optimization of NT loaded surface coated PEGylated NLC (NT-PEG-NLC) using Box-Behnken Design. The optimized NT-PEG-NLC were found to have desirable physicochemical characteristics and exhibited significantly higher transcorneal permeation than Natacyn®, in vitro. In vivo ocular biodistribution of NT-PEG-NLC indicated that, despite NT load in NT-PEG-NLC (0.3%) being 1/16th of Natacyn® (5%), NT-PEG-NLC permeated the intact cornea to reach the inner tissues. To further improve ocular delivery of NT, chapter 3 reports on the development of a gelling system using a full factorial design in which the optimized NT-PEG-NLCs were loaded. This gelling system at a lower NT concentration (0.3%) compared to Natacyn® (5%), displayed superior pharmacokinetic parameters in the tear film and comparable NT concentrations in the inner ocular tissues (in vivo) at a 16-fold lower dose; indicating its potential ocular applications. Chapter 4 reports on the design of Eudragit™ RLPO based ocular films for ocular delivery of NT using central composite design. An optimized film formulation was selected on the bases of the interaction plots between the independent factors and dependent variables; and, it exhibited significantly higher transcorneal permeation (ex vivo) and superior pharmacokinetic parameters (in vivo) compared to Natacyn®. These observations imply that, NT-loaded films could also be explored as alternative dosage forms in the management of OFI

A study on knowledge attitude and practice of contraception in school going children in Wardha district in central India

Background: Adolescent sexuality is leading to adolescent pregnancy, unsafe abortion, Reproductive Tract Infections, Sexually transmitted infections. Therefore, studying knowledge, attitude and practice regarding this problem among school adolescents is an essential issue, which can support to overcome young people from sexual related problems.Methods: This study was cross sectional study conducted in Wardha district of Maharashtra among school going adolescents. Data was collected by the means of anonymous questionnaire after taking the informed consent.Results: In our study total 375 students were included in the study, amongst 192 were girls and 183 were boys. Majority of students belong to age group of 13-15 years. Nearly 50% of students were knowing about basic reproductive physiology. Amongst the total 375 participants, 184 (49%) students had ever heard about any of contraceptive method while 51 % of totally unaware. Among total students having knowledge of contraception, 38.7% knew about condoms, oral contraceptive pills as method of contraception were known to 88 students (23.5%) while knowledge of emergency contraception was very low. The knowledge of females was higher as compared to males regarding oral and emergency contraception. 15% of total adolescents accepted that they have used condom. The proportion of males using condoms was higher as compared to females.Conclusions: The adolescents need to be provided with correct knowledge for behavior change, to stop their undesirable practices for healthy life. There was an evident gap between knowledge and practices with respect to the sexual practices of youth which needs to be bridged.

Short segment pedicle screw fixation of thoracolumbar fracture: a case series of 33 patients

Background: Pedicle screw instrumentation in case of fracture spine provides stable fixation. However in absence of experience and proper technique of pedicle screw insertion, it is associated with many complications. We aim to study the results of patients with thoracolumbar fracture stabilized with short segment pedicle screw instrumentation.Methods: 33 cases of thoracolumbar wedge compression fracture spine presenting to Nair Hospital were included in the study. All patients were operated by the senior author via a posterior approach and short segment pedicle screw fixation. Patients were followed up for one year.Results: 33 patients with a mean age were 37.6 years of which 3 were females and 30 were males in our study. Fall from height (93.93%) was the most common mode of injury followed by road traffic accident (6.07%). D12 and L1 were the most common vertebrae involved. Statistically significant (p=0.01) correction in the vertebral body height occurred in the immediate postop period and there was 4.1% loss of correction at final follow-up. There was statistically significant improvements in the Regional angle (p=0.03) and anterior wedge angle (p=0.03). Residual regional angle at final follow-up was found to be >5° in 3 patients. Neurological improvement was seen in 23 (74.19%) patients (p=0.01). No improvements were seen in 8 (25.81%) patients. None of our patients had postoperative worsening of the neurological status. None of the patients had pedicle wall breach on final follow up CT scan.Conclusions: Short segment fixation in case of wedge fracture can restore the vertebral body height, mean regional angle and mean anterior wedge angle and provide good outcome. There are poor chances of recovery of patient with Frankel grade A. Meticulous dissection and careful technique of pedicle screw insertion, adequate decompression, good contouring of the rod with correction of kyphosis can provide excellent results

Does functional evaluation and magnetic resonance imaging finding in a case of lumbar canal stenosis co-relate: a study of 50 cases

Background: Lumbar canal stenosis is a clinical diagnosis. MRI is used many times for making the diagnosis. But does the severity of MRI findings co-relate with functional status?Methods: 50 cases of central lumbar canal stenosis were included in the study. The MRI findings and Oswestery Disability Index score were compared.Results: 50% of patients with severe ODI score had no Stenosis in the MRI. MRI findings do not co-relate with the functional severity of the disease (p=0.03).Conclusions: MRI and ODI score does not co-relate. This study reinforces the fact that one should always treat the patient and not the MRI.

Review on Nanorobot as a Nanomachine and Biomedicine

Nanorobotics is the technology of producing robots or machines with very small scale or Miniscale of a nanometer (10-9 meters), machines constructed at the molecular level (Nano machines) may Be used to detect or identify and cure the human body of its various diseases like cancer. Nano robots are Very good accuracy they perform a specific task with great accuracy and precision at very small scale or Nanoscale dimension. A recent discovery in the field of drug Delivery is target therapy, which improves the diagnostic tests and Medical devices. Nanotechnology is going to revolutionize the world. According to the National Nanotechnology Initiative (NNI). Nowadays these nano robots play a vital role in the field of Bio Medicine. In the pharma-world, the applications of Nanotechnology mean drugs containing nano-sized active ingredients. They are well used to cure HIV, Cancer, Surgery, Bloodstream, gene therapy, Kidney stone removal and other harmful disease they Can restore lost tissue at the cellular level, useful for monitoring, Diagnosing and fighting sickness. The main purpose is to cure many dreadful Diseases in human body

Thermoeconomic Diagnosis Of Air Conditioning Systems: Experimental Assessment Of Performance And New Developments For Improved Reliability

In the last two decades, great progress has been made in improving the efficiency of air-conditioning equipment. In addition to improved performance of new equipment, there has been an increasing interest in technologies that can maintain performance over time. This has led to research and development of Fault Detection and Diagnosis (FDD) techniques for air conditioning systems, that can support building owners in scheduling cost-effective maintenance and repairs. Among FDD techniques, thermoeconomic diagnosis is a novel method for the identification of faults occurring in air conditioning systems. A very limited number of papers have focused on this topic, and the methodology is still at a very early stage of development. Thermoeconomic diagnosis is an exergy-based method to quantify the additional energy consumption (or the EER penalty) associated with individual or combinations of faults. It has been initially tested for very simple vapor compression systems through simulation, but has never been evaluated using experimental data. This work aims to assess the performance of thermoeconomic diagnosis using experimental data obtained from a five-ton variable-speed packaged rooftop air conditioning unit (RTU). The RTU was tested in psychrometric chambers under a wide range of operating conditions and fault levels. Three faults that are commonly found in rooftop systems were investigated: (i) evaporator fouling, (ii) condenser fouling and (iii) refrigerant undercharge. The experimental results were used as inputs in an equipment model, to characterize the exergy behavior of each component in presence of faults and apply the approach of Symbolic Exergoeconomics. Experimental results show the technique had difficulty in detecting some faults and its performance is quite sensitive to operating conditions. Based on these results, improvements to the FDD methodology based on empirical models of plant components are proposed. These improvements act to isolate the effects of operating conditions from the thermoeconomic effects of different faults, improving overall performance

Impact of Virtual Building Model and Thermostat Installation on Performance and Dynamics of Variable-Speed Equipment during Load-based Tests

To better characterize the performance of variable-speed DX (Direct Expansion) equipment in a laboratory environment, a load-based psychrometric chamber testing methodology has been developed as an alternative to existing steady-state testing approaches. The methodology allows equipment to respond dynamically to a virtual building model using its integrated controls. To mimic an actual building, a virtual building model incorporates sensible and latent loads along with simple lumped capacitance building dynamics that interact with the variable-speed equipment. The rated capacity of the test equipment is used along with a specified sizing factor and target sensible heat ratio (SHR) to specify the building sensible and latent load models. In addition, heuristic approaches are used to specify and scale sensible and latent capacitances of the virtual building model. Two companion papers present the overall methodology and results for different variable-speed heat pumps using default building parameters. This paper studies the impact of the virtual building load parameters on overall performance and dynamic behavior of the equipment for load-based testing. It is shown that equipment seasonal performance can increase significantly with increasing sizing factor. In addition, performance increases with decreasing building SHR results. In addition to simple lumped capacitance models, more detailed two-node models are investigated to evaluate more realistic dynamics and their impacts on seasonal efficiency ratings. In addition, the impact of the thermostat location on equipment dynamics and performance ratings is considered

Performance Evaluation of Heat Pump Systems Based on a Load-based Testing Methodology

This paper presents results of testing variable-speed heat pumps using a new load-based testing methodology that is described in a companion paper. The testing methodology involves emulating the response of a building’s sensible and latent loads to equipment controls by dynamically adjusting the temperature and humidity setpoints of the psychrometric chamber reconditioning system using a simple building model. The advantage of this approach over existing testing approaches specified in ratings standards is that it considers the interaction of the integrated controls with the equipment. As a result, it better captures the full range of part-load operation and the benefits of improved controls. This paper presents performance results for application of the automated load-based testing methodology to different variable-speed residential heat pump systems. In order to assess the benefits of load-based testing versus existing standards, tests were also conducted based on AHRI 210/240 and seasonal performance estimates are compared using data obtained with the two testing approaches