2,464 research outputs found
A comparative study of various strategies used for the mitigation of global warming
The global temperature has risen yearly by a bit more than 1 degree Celsius during the industrial revolution. Many experts believe that if current greenhouse gas emissions continue, the planet will become hotter, ocean level will rise and climatic conditions will change excessively. Temperatures are expected to rise faster in the coming decades than they have in the previous 10,000 years, according to some scientists. Greenhouse gases are thought to be the most important factor causing climate change. CO2 is by far the most important anthropogenic greenhouse gas, with concentration in the atmosphere rising by more than 80% between 1970 and 2021. About 91 percent of total CO2 emissions from human sources come from fossil fuels. Controlling greenhouse gas emissions and preparing human settlements to withstand extreme climate change have emerged as two of our age\u27s most daunting challenges. The purpose of this study is to discuss and compare various strategies that can be used for reducing or eliminating carbon dioxide emissions. Various CO2 reduction approaches have been investigated, including the replacement of fossil fuels with renewable energy sources, carbon dioxide capture and storage, and carbon dioxide capture and utilization. The goal of this research is to look at several options for meeting energy needs for long-term development without causing negative climate change i.e. renewable energy sources, carbon dioxide capture and storage, carbon dioxide capture and utilization
A Small Open Economy DSGE Model for Pakistan
This paper estimates a small open economy Dynamic Stochastic General Equilibrium (DSGE) model for Pakistan using Bayesian simulation approach. Model setup is based on new Keynesian framework, characterized by nominal rigidity in prices with habit formation in household’s consumption. The core objective is to study whether an estimated small open economy DSGE model provides a realistic behavior about the structure Pakistan economy with fully articulated description of the monetary policy transmission mechanism vis-à-vis domestic firm’s price setting behavior. To do so, we analyze the impulse responses of key macro variables; domestic inflation, imported inflation, output, consumption, interest rate, exchange rate, term of trade to different structural/exogenous shocks. From several interesting results, few are; (a) high inflation in Pakistan do not hit domestic consumption significantly; (b) Central bank of Pakistan responds to high inflation by increasing the policy rate by 100 to 200 bps; (c) exchange rate appreciates in both the cases of high domestic and imported inflation; (d) tight monetary policy stance helps to curb domestic inflation as well as imported inflation but appreciates exchange rate significantly (f) pass through of exchange rate to domestic inflation is very low; finally parameter value of domestic price stickiness shows that around 24 percent domestic firms do not re-optimize their prices which implies averaged price contract is about two quarters.New-Keynesian economics; open economy DSGE models; nominal rigidities; monetary policy transmission mechanism; Bayesian Approach
Development And Performance Evaluation Of Smart Polymeric Coatings For Corrosion Protection Of Steel
Most common cause of materials and equipment failure in the oil and gas industry is corrosion. According to one survey, about 1/4 to 1/3 of the total downtime in plants is due to deleterious effects of corrosion. It is, therefore, essential to prevent corrosion to ensure reliability of the assets. Usually, Protection of piping steel against corrosion is achieved by applying thick barrier coatings. These coatings provide decent barrier protection against ageing, mechanical scratches, erosion and other damages. Protection of damaged piping parts requires steel repair and re-coat which is an expensive process. To minimize the impact of damages and subsequent corrosion activity of the steel is essential to act promptly and efficiently, preferably in an autonomous way. Modern trends indicate that smart functional coatings, containing autonomous self-healing species are attractive for prolonged lifetime of materials. These coatings can heal damages at early stage, minimizing corrosion onset and corrosion propagation. Consequently, they are a promising solution for longer durability of coated piping steel and decreased operation expense. If properly designed, smart self-healing coatings also help to reduce the overall thickness of the coating scheme as well as the investment cost. Altogether, this strategy contributes to economic saves, materials reliability and safety. The current research work summarizes the synthesis and characterization of polymeric smart coatings developed by reinforcing urea formaldehyde microcapsules encapsulated with linalyl acetate and polyelectrolyte multilayered microcapsules (with two different corrosion inhibitors in the polyelectrolyte layers) into epoxy matrix. In situ polymerization technique was used for the synthesis of urea formaldehyde microcapsules encapsulated with linalyl acetate, whereas layer by layer technique was adopted to develop multilayered microcapsules containing alternative layers of Polyethyleneimine (PEI) and sulphonated polyether ether keytone (SPEEK). Dodecylamine (DOC) and phenylethiourea (PTU) were loaded as corrosion inhibitors in between polyelectrolyte layers of PEI and SPEEK. The prepared microcapsules (each 6.0 wt.% ) were uniformly dispersed into the epoxy resin to develop single layer coatings (reinforced with urea formaldehyde microcapsules) and multilayered smart coatings (reinforced with multilayered microcapsules). The anticorrosive performance of the fabricated coatings was evaluated in 3.5 % NaCl solution at room temperature. Experimental results confirm that smart coatings with multilayered microcapsules demonstrate improved self-healing and anti-corrosion properties when compared to other type of coatings. This improvement can be attributed to efficient release of self
healing and corrosion inhibiting species (DOC and PTU) from the multilayered microcapsules. The tempting properties of multilayered coatings make them attractive for oil and gas industries
A Small Open Economy DSGE Model for Pakistan
This paper estimates a small open economy Dynamic Stochastic General Equilibrium (DSGE) model for Pakistan using Bayesian simulation approach. Model setup is based on new Keynesian framework, characterised by nominal rigidity in prices with habit formation in household’s consumption. The core objective is to study whether an estimated small open economy DSGE model provides a realistic behavior about the structure Pakistan economy with fully articulated description of the monetary policy transmission mechanism vis -à-vis domestic firm’s price setting behavior. To do so, we analyse the impulse responses of key macro variables; domestic inflation, imported inflation, output, consumption, interest rate, exchange rate, term of trade to different structural/exogenous shocks. From several interesting results, few are; (a) high inflation in Pakistan do not hit domestic consumption significantly; (b) Central bank of Pakistan responds to high inflation by increasing the policy rate by 100 to 200 bps; (c) exchange rate appreciates in both the cases of high domestic and imported inflation; (d) tight monetary policy stance helps to curb domestic inflation as well as imported inflation but appreciates exchange rate significantly (f) pass through of exchange rate to domestic inflation is very low; finally parameter value of domestic price stickiness shows that around 24 percent domestic firms do not re-optimise their prices which implies averaged price contract is about two quarters.New-Keynesian Economics, Open Economy DSGE Models, Nominal Rigidities, Monetary Policy, Transmission Mechanism, Bayesian Approach
What are the smart COVID-19 containment options for developing countries?
What are the smart COVID-19 containment options for developing countries? Adnan Q. Khan (LSE) writes that the pandemic has pushed policymakers there into an environment of great uncertainty. Not surprisingly, many governments have been emulating the policies of other countries before them. However, while continuing with blanket enforcement of lockdown measures may temporarily stop the spread of the virus, it could quickly generate a new kind of crisis in the form of a rise in non-COVID diseases, deprivation, and hunger, especially in the developing world
Assessment of Geotechnical Properties of Laki Limestone for Coarse Aggregate, Nooriabad, Jamshoro Sindh, Pakistan
Present study is aimed at assessment of geotechnical properties of Laki limestone as coarse aggregate which is being quarried in Nooriabad area, Sindh, Pakistan. Coarse aggregate samples (n=20) of limestone were collected for the evaluation of physico-mechanical properties of the aggregate. Petrographic analysis revealed that the aggregate comprises of hard, compact, massive, crystalline and fossiliferous limestone. It is devoid of any reactive silica (chert, chalcedony) and other harmful constituents like clays or organic matter. Average values of specific gravity, absorption,bulk density, void content and combined index (EI + FI) of collected samples are 2.5, 2.1%, 1.54 g/cc, 38.55% and 13.04% respectively. The values of specific gravity (2.3-2.9), absorption (0-8%), bulk density (1.28 g/cc-1.92 g/cc) and void content (30%-45%) are varying within the range of normal weight aggregate as per American concrete institute (ACI)specifications. On the other hand, absorption values of aggregate samples are slightly higher (2.1%) than the reference range (2%) but meet other requirements. Mechanical properties including aggregate impact value (8.58%), aggregate crushing value (26.66%), Loss Angeles abrasion value (24.77%), sodium sulfate soundness (4.72%), water soluble sulfate (0.006%) and water soluble chloride (0.005%) are found to be within corresponding guidelines set by ASTM. On the other hand, average carbonate content is found to be 89.64% indicating that Laki limestone is of slightly low purity. Except absorption, all physical and mechanical properties lie within specified ranges. It is concluded that Laki limestone is suitable for use as road aggregate and concrete mix design
Fate of Benzalkonium Chlorides in Natural Environment and Treatment Processes
Benzalkonium chlorides (BACs) are a type of cationic surfactant and are highly adsorptive to negatively charged surfaces during the wastewater treatment process. They can, therefore, enter the aquatic environment via the suspended organic matter in wastewater effluents, and the terrestrial environment through the application of biosolids as a soil amendment for crop production or by the use of reclaimed wastewater for irrigation. This research investigated the fate of the two most commonly used BACs, benzyl dimethyl dodecyl ammonium chloride (BDDA; C12-alkyl chain) and benzyl dimethyl tetradecyl ammonium chloride (BDTA; C14-alkyl chain), individually and in mixture in various natural and engineered systems.
Under laboratory conditions, the following potential fate processes of these BACs were investigated: bacterial biodegradation, adsorption and leaching in various agricultural soils amended with biosolids, and plant uptake. A pure Pseudomonas strain biodegraded BACs, but BDTA was more toxic and inhibited the biodegradation of BDDA. Radiolabelled [U-14C-benzyl] BDDA showed about 85% of the initial concentration mineralized within 300 h. Adsorption studies of BACs to agricultural soils showed, BDTA adsorbed more on soil compared to BDDA. Organic carbon normalized adsorption coefficients (Log Koc, L kg–1) for BACs in the soils were \u3e4, which suggested that BACs tend to retain on the organic fraction of soils. Soil column experiments indicated very low leaching (–1 BACs inhibited plant growth to 50% and BACs were found in the root and shoot tissues of both garden cress (Lepidium sativum) and lettuce (Lactuca sativa).
An advanced oxidation process (AOP) based on O3/H2O2 showed that about 1.28 g h–1 O3 and 200 mg L–1 of H2O2 at pH 11 degraded 90% of the initial BACs within 30 min. The AOP treated water was not toxic to two species of algae (Chlorella vulgaris and Chlamydomonas reinhardtii); growth rate was about 0.38 d-1 for treated and control samples compared to 0.01 d-1 for samples contained BACs without AOP. About 25 transformation products were identified in the AOP processes following six different degradation pathways
An Intelligent and Secure Communication of AIoT enabled Devices empowered with IPK Algorithm
Artificial intelligence Internet of Things (AIoT) will be a necessary part of our lives in the near future. It will be found as quick cooperation in our surroundings through the related sensor-based system. To be sure, even in an indirect method, it will serve us in a couple of structures as esteem included organizations over the cell stages. With the AIoT structures that make usage of data, actually, the data collection from contraptions can in like manner be a goal of cyberattacks. Device to Device (D-2-D) interchanges in AIoT was planned alongside various shows, for instance, Constrained Access Protocol (CoAP). Its huge stresses in the course of action of AIoT are to ensure the security of mechanisms and D-2-D one place to another. Furthermore, present correspondence shows for AIoT arewithout reliability features. It is a result of this that countermeasures in perspective on encryption are starting at now getting importance. There is a requirement for a solid cryptosystem for D-2-D in AIoT. In this investigation paper, we present an encryption technique which is indicated as EPEB as a security answer for AIoT. The proposed methodology works with the message which shows special characters, numbers, and bits for data encryption and decryption. In authority, the end key isn't known so we would encryption to able have the option to gadgets data using particular keys and scramble packet per specialkey
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