Constraint-based Query Distribution Framework for an Integrated Global Schema

Distributed heterogeneous data sources need to be queried uniformly using global schema. Query on global schema is reformulated so that it can be executed on local data sources. Constraints in global schema and mappings are used for source selection, query optimization,and querying partitioned and replicated data sources. The provided system is all XML-based which poses query in XML form, transforms, and integrates local results in an XML document. Contributions include the use of constraints in our existing global schema which help in source selection and query optimization, and a global query distribution framework for querying distributed heterogeneous data sources.Comment: The Proceedings of the 13th INMIC 2009), Dec. 14-15, 2009, Islamabad, Pakistan. Pages 1 - 6 Print ISBN: 978-1-4244-4872-2 INSPEC Accession Number: 11072575 Date of Current Version : 15 January 201

Determinants of working capital management efficiency: Case study of Pakistani automotive and engineering firms listed in Karachi Stock Exchange

This Study is conducted to determine the determinants of working capital management efficiency of automotive and engineering firms listed in Karachi Stock Exchange of Pakistan. Cash Conversion Cycle, Days sales Inventory, Days Payable Outstanding and Days Sales Outstanding are the explanatory variables. Whereas the descriptive statistics, Pearson’s Bivariate correlation analysis and ordinary pooled least square with fixed effect model are applied to investigate the significance of panel data set. It is quarterly based and secondary data in nature that comprises of 9 firms for 5 years. The observations are taken from financial years 2006 to 2010 of the listed firms. In spite of these a questionnaire is also filled by the firm’s financial representatives during the research on Enterprise Resource Planning (ERP) which shows positive results or the efficiency of working capital management. It is concluded that to keep the working capital efficient cash conversion cycle must be shortest. For this there is need of tight collection policy and liberal payment policy while the inventory management must be efficient by reviewing the inventory policy

Factors Affecting Quality of Sleep in Intensive Care Unit

Background: The etiology of sleep disruption in intensive care unit is poorly known and often ignored complication. It is caused by the environmental factors especially pain, noise, diagnostic testing and human interventions that cause sleep disruption. Light, medications and activities related to patient care interfere with patient's ability to have good sleep. There are multi-factorial environmental etiologies for disruption of sleep in ICU. Objective: The objective of this study was to evaluate the factors disturbing the sleep quality in intensive care unit (ICU) admitted patients. Methodology: A cross sectional study was designed involving 150 patients admitted in intensive care unit and high dependency unit of Gulab Devi Chest Hospital. The duration of study was from September 2015 to March 2016. The questionnaire was made and filled with the help of patients. The data was analyzed using SPSS version 16.00. Results: Mean age of patients was 50.46+10.96 with maximum age of 65 and minimum age of 30 years. There was 53.33% male patients and 46.67% females participating in this study. The sleep quality was significantly poor in ICU than at home. After analysis, 54.67% patients were with poor quality of sleep due to pain and 48.67% were due to noise of environmental stimuli. The other factors were alarms, light and loud talking. Conclusion: Current study shows that reduced sleep quality is a common problem in ICU with multi-factorial etiologies. Patient reported the poor sleep quality in ICU due to environmental issues that are potentially modifiable. Conclusion: Current study shows that reduced sleep quality is a common problem in ICU with multi-factorial etiologies. Patient reported the poor sleep quality in ICU due to environmental issues that are potentially modifiable

Investigation of self switching flux pump for high temperature superconducting magnets

The rapid development of second-generation (2G) high-temperature superconducting (HTS) coated conductors (CCs) has made it possible to manufacture 2G HTS coils with enormous potential for a wide range of applications, including magnetic resonance imaging (MRI) magnets, electrical propulsion systems (HTS machines), magnetic levitation trains, and energy storage (SMES). While these coils can be operated using either DC or AC current, challenges such as properly magnetizing an HTS coil under DC conditions and reducing losses under AC conditions still need to be addressed before their widespread use in scientific and industrial settings. Typically, high-current power supplies power these coils through current leads, which can complicate insulation between cryogenic and room temperature environments. Fortunately, HTS flux pumps provide an alternative method of energizing superconducting magnets without the need for direct electrical contacts, reducing resistive heating and heat leakage from current leads at room temperature. Recent developments in flux pumps for HTS magnets have made it possible to charge kA levels of current without the need for thick current leads. This thesis aims to provide a comprehensive investigation of charging an HTS magnet to operate it in a persistent current mode, and presents a novel perspective on controlling the magnetic field in HTS magnets via flux pumping. First a two-dimensional (2D) model of a single turn high-temperature superconducting (HTS) coil was developed using a well-established H-formulation, which was iteratively refined to eliminate numerical errors from the solution. The resulting model provides insights into the self-rectifying flux pumping mechanism, which was subsequently validated experimentally. The 2D model also enables the estimation of the over-critical current voltage (also known as the flux flow voltage) across the HTS tape, which acts as a stable voltage source for injecting current into the HTS magnet. This results in the quantization of the bridge voltage, enabling precise flux injection into a fully superconducting circuit. A higher stable dc voltage can be achieved across the terminals of the HTS magnet using a bifilar coil as a bridge (bridge – the HTS tape short-circuits the terminals of the magnet and the secondary coil), the results are verified experimentally. The influence of the HTS tape and bifilar coil acting as a bridge across the HTS magnet is investigated. The results show that the bifilar bridge gives higher stable dc voltage to charge the HTS magnet to its critical current values and leads to the compact geometry making it suitable for adoption to complex geometries like rotor magnets in HTS machines. HTS flux pumps can charge the magnet and compensate for any current decay, enabling quasi-persistent operation of HTS magnets. To operate an HTS magnet in the persistent current mode, a jointless HTS magnet is constructed that offers zero joint resistance, allowing it to operate in persistent current mode. However, when used in applications like rotors of fully superconducting machines, it continuously experiences a background magnetic field in the form of magnetomotive force coming from the stator. The external alternating field can cause a gradual decay of the magnetic field. Therefore, this work presents a closed-loop feedback control for field modulation in HTS magnets to operate in persistent current mode. This method eliminates the need for continuous flux pumping and allows for the injection and reduction of current in increments of 0.5 A. This flux modulation can enable a stable magnetic field for HTS magnets. Finally, the thesis investigates critical aspects of the flux pumping in HTS magnets operating at 30 K, marking an advancement in the field of HTS magnet technology as previous flux pumps have only been reported to operate at higher temperatures. These results provide insight into achieving a stable magnetic field in HTS magnets via flux pumping and outline the methods to compensate for current decay in HTS magnets operating in the persistent current mode – opening new pathways to high-field, low-cost HTS magnets.The rapid development of second-generation (2G) high-temperature superconducting (HTS) coated conductors (CCs) has made it possible to manufacture 2G HTS coils with enormous potential for a wide range of applications, including magnetic resonance imaging (MRI) magnets, electrical propulsion systems (HTS machines), magnetic levitation trains, and energy storage (SMES). While these coils can be operated using either DC or AC current, challenges such as properly magnetizing an HTS coil under DC conditions and reducing losses under AC conditions still need to be addressed before their widespread use in scientific and industrial settings. Typically, high-current power supplies power these coils through current leads, which can complicate insulation between cryogenic and room temperature environments. Fortunately, HTS flux pumps provide an alternative method of energizing superconducting magnets without the need for direct electrical contacts, reducing resistive heating and heat leakage from current leads at room temperature. Recent developments in flux pumps for HTS magnets have made it possible to charge kA levels of current without the need for thick current leads. This thesis aims to provide a comprehensive investigation of charging an HTS magnet to operate it in a persistent current mode, and presents a novel perspective on controlling the magnetic field in HTS magnets via flux pumping. First a two-dimensional (2D) model of a single turn high-temperature superconducting (HTS) coil was developed using a well-established H-formulation, which was iteratively refined to eliminate numerical errors from the solution. The resulting model provides insights into the self-rectifying flux pumping mechanism, which was subsequently validated experimentally. The 2D model also enables the estimation of the over-critical current voltage (also known as the flux flow voltage) across the HTS tape, which acts as a stable voltage source for injecting current into the HTS magnet. This results in the quantization of the bridge voltage, enabling precise flux injection into a fully superconducting circuit. A higher stable dc voltage can be achieved across the terminals of the HTS magnet using a bifilar coil as a bridge (bridge – the HTS tape short-circuits the terminals of the magnet and the secondary coil), the results are verified experimentally. The influence of the HTS tape and bifilar coil acting as a bridge across the HTS magnet is investigated. The results show that the bifilar bridge gives higher stable dc voltage to charge the HTS magnet to its critical current values and leads to the compact geometry making it suitable for adoption to complex geometries like rotor magnets in HTS machines. HTS flux pumps can charge the magnet and compensate for any current decay, enabling quasi-persistent operation of HTS magnets. To operate an HTS magnet in the persistent current mode, a jointless HTS magnet is constructed that offers zero joint resistance, allowing it to operate in persistent current mode. However, when used in applications like rotors of fully superconducting machines, it continuously experiences a background magnetic field in the form of magnetomotive force coming from the stator. The external alternating field can cause a gradual decay of the magnetic field. Therefore, this work presents a closed-loop feedback control for field modulation in HTS magnets to operate in persistent current mode. This method eliminates the need for continuous flux pumping and allows for the injection and reduction of current in increments of 0.5 A. This flux modulation can enable a stable magnetic field for HTS magnets. Finally, the thesis investigates critical aspects of the flux pumping in HTS magnets operating at 30 K, marking an advancement in the field of HTS magnet technology as previous flux pumps have only been reported to operate at higher temperatures. These results provide insight into achieving a stable magnetic field in HTS magnets via flux pumping and outline the methods to compensate for current decay in HTS magnets operating in the persistent current mode – opening new pathways to high-field, low-cost HTS magnets

The Perils of Non-State Actors in Pakistan: Assessing the Risks of Nuclear Safety and Security

Pakistan is facing security problems on multiple fronts, including economic default, social fragmentation, poor civil–military relations, political polarization, and environmental degradation. However, the biggest security threat comes from non-state actors (NSAs) and terrorism. Using empirical evidence, this research paper evaluates the risk of nuclear terrorism by NSAs in Pakistan. It adopts an interpretive approach to examine international concerns regarding nuclear security in Pakistan. The study focuses on the potential for technology and weapon-usable materials to fall into the hands of violent NSAs. It concludes that, despite ongoing security challenges, Pakistan has taken steps to strengthen its legislative and institutional measures to protect its nuclear infrastructure

Effectiveness of Pulmonary Rehabilitation in Patients with COPD

Background: Pulmonary rehabilitation (PR) is beneficial for patients with COPD, with improvement in exercise capacity and health-related quality of life. Despite these overall benefits, the responses to PR vary significantly among different individuals. It is not clear if PR is beneficial for patients with COPD and normal exercise capacity. Although it is believed that longer pulmonary rehabilitation programs can provide better results, most of the evidence comes from short-term programs. Objective: The objective of this analysis was to determine the effectiveness of respiratory services provided in the hospital or community by respiratory therapists (RTs) in reducing health care utilization and improving patient outcomes. The aim was to evaluate the outcomes of a comprehensive pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease. Methodology: All 65 Pakistani patients who met the inclusion criteria with ages between 40 to 65 years, including both male and female, with mild to severe COPD were enrolled in the study on the basis of convenient sampling. Informed consent was taken from each patient starting about the study and their rights to withdraw from study. A demographics detail (name, age, sex) was noted along with the necessary medical history. A questionnaire was made to see the effects of pulmonary rehabilitation in patients with COPD. All necessary tests were performed to evaluate the patient betterment completely. Results: The mean FEV1 in the subjects was 1.29 ± 0.47 L/min, 64.8 ± 23.0% of predicted. Clinically there is a little effect on CXR pattern, FEV1 and FEV1/FVC after pulmonary rehabilitation. But overall quality of life improved after pulmonary rehabilitation. Mainly improvement occurs in peak expiratory flow rate, BORG dyspnea scale, 6 mint walk test distance (meters) and Oxygen saturation after rehabilitation. Conclusion: These results showed that patients with COPD had benefited from a comprehensive PR program in an out-patient setting regardless of disease severity. Exercise training can result in significant improvement in health-related quality of life, exercise capacity, respiratory muscle strength, and exertional dyspnea in subjects with COPD and normal exercise capacity