The impact of population, affluence and technology on the environmental degradation : evidence from heterogeneous income panels

Efficient utilization of scarce resources is always the prime aim of every state to ensure social welfare, while maintaining clean and green environment to sustainable development. The growing threats of global warming and climate changes have called for more sensible attention of the· policy makers. Therefore, this study is an attempt to empirically investigate the linkages between population, affluence, technology, and environmental degradation for selected low, lower middle, upper middle, and high-income countries using disaggregate and aggregate panel data over the period 1980-2015. After checking the stationary properties of the data, Pedroni (1999) tests of co integration were implemented for cointegration purposes. The FMOLS was employed for parameters estimation. The results show that population, nonrenewable energy consumption, urbanization, population growth, international trade and total energy consumption are the main culprits of CO₂ emissions in all selected panels whereas renewable energy consumption is found helpful in curbing the amount of CO₂ emissions. In addition, GDP growth FDI and financial development are found having insignificant relationship with CO2 emissions. Finally, results of Granger causality suggest that the population size, population density and urbanization are usually granger causes of CO₂ emissions. The findings of the study suggest important policy implications. This study recommends scientific planning fur urban development, developing environmental awareness, among urban residents, encouraging the adoption of more fuel-efficient vehicles, increasing the entire costs of private transport as a few measures to lower the energy consumption and CO₂ emissions. Furthermore, it is advised that policymakers should regulate such policies to trigger international trade activities as international trade detracts CO2 emissions. In this regard, exploring the alternative energy policies, such as developing energy conservation strategies, decreasing the energy intensity, increasing the energy efficiency, and increasing the utilization of cleaner energy sources can prove better strategies to handle this issue

Analysis, Perception and Aspects of Risk Management in the Construction Sector of Pakistan

Management of risk is very significant in the construction sector of Pakistan. Firstly, risk and uncertainty are defined and described in detail. Risk management and risk management process is also defined, described and explained. This risk and risk management provided necessary details and background for this study. A questionnaire survey was conducted for collection of data and information about risk management in Pakistan. Interviews were also conducted for the deeper investigation, study and analysis of the particular specific aspects of risk management in construction sector of Pakistan. Data analysis was done on the basis of data, information, ideas and views regarding risk management from the results of questionnaire survey and interviews. In data analysis, we discussed the aspects of risk management, documentation analysis, research trustworthiness, contracting types and the role of collaborative relationships such as relational contracting and joint risk management. This analysis and discussion provided the important concepts of better and effective risk management. Keywords: Construction Project, Risk Management, Questionnaire Survey, Interview, Analysis

Defense expenditure and economic growth: A case study of Pakistan

The objective of this study was to examine whether there is exists a long run relationship between defense expenditure and economic growth, and investigate the plausibility of using defense expenditure as a macroeconomic stabilization tool (referred as Military Keynesianism Hypothesis) in case of Pakistan over the period 1975–2010. The Autoregressive Distributed Lag (ARDL) bounds testing approach was used to find out long run relationship between defense expenditure, economic growth, development expenditure, inflation and national saving. The Augmented Dickey-Fuller (ADF) test was used for checking stationarity. The results of ADF test revealed that inflation and saving are stationary at level while defense expenditure, development expenditure and GDP become stationary at first difference. Results of ARDL indicated that data is stable and confirmed the existence of long run relationship. The robustness of the model has been confirmed by diagnostic tests for serial correlation, function form, normality, hetroscedasticity, and structural stability for the model. The selected model generally passes all diagnostic tests and proves the robustness of the selected model. Moreover, results show that defense expenditure has negative impact on economic growth while saving has positive impact on economic growth but other variables have no impact on economic growth. These results for long run negative relationship between defense expenditure and economic growth suggest that in case of Pakistan MKH does not hold over the estimation period. The negative long run relationship between defense expenditure and economic growth implies that the policy makers need to have a greater focus on development spending as compared to defense spending

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

Review of Sustainable Concrete: Building a Waste-Free and Sustainable Future

Although concrete is one of the most beneficial material for the mankind yet it is one of the most unsustainable material as well. Concrete production is majorly dependent on the utilization of natural resources and is depleting the environment at an alarming rate. In order to protect the depletion of our environment, we need to introduce modern tools, sustainable materials, and processes to produce sustainable concrete. Moreover, instead of using fresh water for concrete production that could otherwise be used as drinking water, we could use alternative sources of water such as wastewater or seawater. In this review paper readers will get to know about different techniques which will help to build a waste free and sustainable environment hence reducing the environmental impact of concrete. We can use different sources of wastes to reduce the amount of binder and aggregates used for concrete production hence reducing the environmental impact of binder, coarse aggregates, and fine aggregates. Different waste materials from industrial, agricultural and domestic sources are reviewed which will help in production of sustainable concrete

High Performance Computing Framework for Tera-Scale Database Search of Mass Spectrometry Data

Database peptide search algorithms deduce peptides from mass spectrometry data. There has been substantial effort in improving their computational efficiency to achieve larger and more complex systems biology studies. However, modern serial and high-performance computing (HPC) algorithms exhibit suboptimal performance mainly due to their ineffective parallel designs (low resource utilization) and high overhead costs. We present an HPC framework, called HiCOPS, for efficient acceleration of the database peptide search algorithms on distributed-memory supercomputers. HiCOPS provides, on average, more than tenfold improvement in speed and superior parallel performance over several existing HPC database search software. We also formulate a mathematical model for performance analysis and optimization, and report near-optimal results for several key metrics including strong-scale efficiency, hardware utilization, load-balance, inter-process communication and I/O overheads. The core parallel design, techniques and optimizations presented in HiCOPS are search-algorithm-independent and can be extended to efficiently accelerate the existing and future algorithms and software

Prognostic Role of Optical Coherence Tomography in Outcome of Idiopathic full thickness Macular Hole Surgery

Abstract Purpose: To assess the prognostic value of Optical Coherence Tomography indices preoperatively in outcome of idiopathic full thickness macular hole surgery. Material & Methods:  A Quasi experimental study was carried out at Al Ibrahim eye hospital, Karachi from June 2019 to Feb 2020. Patients between 50 to 70 years of age, including both genders with full thickness idiopathic macular hole on Optical Coherence Tomography (OCT) were included while patients with secondary causes of macular hole like trauma, myopia, detachment of retina with macular hole, macular hole with other causes of poor vision like corneal scaring, Age related macular degeneration and diabetic retinopathy were excluded. OCT measurements are basal diameter, height of macular hole, right and left arm length and derived indices are macular hole index (MHI) and hole form factor (HFF). Results: A total 33 patients including 23 (69.6%) male and 10(30.3%) females of idiopathic full thickness macular hole were taken. Patients  mean age was 55.25±6.9. Among 33 patients, MHI (>0.5) was found in 21(63.6%) patients while 12 (36.3%) patients had MHI (< 0.5). In 25 patients HFF calculation was possible. 17(68%) patients had HFF (>0.9) while 8  (32%) patients had HFF (< 0.9). Anatomical and visual outcomes were assessed at 1st and 3rd month follow-up. Of 21 patients for MHI >0.5, vision improved (i.e. ≥ 6/18) in 15 (71.4%). Similarly, out of 17 patients for HFF > 0.9, 13 (76.47%) patients had improved vision post-operatively. Conclusion: Optical coherence tomography indices can be helpful to predict surgical outcomes of idiopathic full thickness macular hole surgery

High Performance Computing Algorithms for Accelerating Peptide Identification from Mass-Spectrometry Data Using Heterogeneous Supercomputers

Fast and accurate identification of peptides and proteins from the mass spectrometry (MS) data is a critical problem in modern systems biology. Database peptide search is the most commonly used computational method to identify peptide sequences from the MS data. In this method, giga-bytes of experimentally generated MS data are compared against tera-byte sized databases of theoretically simulated MS data resulting in a compute- and data-intensive problem requiring days or weeks of computational times on desktop machines. Existing serial and high performance computing (HPC) algorithms strive to accelerate and improve the computational efficiency of the search, but exhibit sub-optimal performances due to their inefficient parallelization models, low resource utilization and high overhead costs