Climatic Events and Natural Disasters of 21st Century: A Perspective of Pakistan

In recent years, the frequent occurrence of natural calamities in the world has gained much attention due to infrastructure and life losses. Increase in global temperature has threatened the earth’s climate, causing unpredictable and extreme weather events more often. These events were both short-term as well as long-term. In spite of insufficient monitoring coverage of inner areas and high altitudes, an intensification of average yearly temperature has been observed after the 20th century in many regions of Asia. Pakistan has faced a number of natural disasters including severe floods, devastating earthquakes, disturbing droughts, distressing smog, extreme temperature and torrential rainfall patterns. These calamities have affected people economically, socially, physically and mentally by posing a threat to earth, its species and their livelihood. This paper was aimed to document the natural calamities in Pakistan since the beginning of 21st century till date. The country is facing the problem of intense and longer summers and has witnessed two intense heat waves. Moreover, in some areas, extensive droughts are threatening crops, freshwater supply and wildlife. In recent years, the problem of smog has emerged in Pakistan, especially in Punjab. The problem is getting worse in every coming year due to overpopulation, cities expansion, increased emission of greenhouse gases, open burning of crop residues and extreme reliance on fossil fuels for energy purpose. So far in this century, Pakistan has faced 3 droughts, 2 heat waves, 10 severe floods, 27 major earthquakes, 2 consecutive sessions of severe smog and extreme high and low temperature events. Some of the deadliest events were; 2005 Kashmir earthquake claiming 87,350 human lives and 2010 flood impacting nearly 20 million people with 1,781 causalities. Change in climate is posing a severe threat to species, livelihood of the human beings and the earth. Global warming is causing warming of oceans and consequently rise in sea level. Climate change affects average as well as extreme temperatures hence increasing the probability climate-related disasters. Thus, global warming is causing a chain of catastrophic events that make the problem even more complex to understand

Systematic Investigation of Structural, Morphological, Thermal, Optoelectronic, and Magnetic Properties of High-Purity Hematite/Magnetite Nanoparticles for Optoelectronics

Iron oxide nanoparticles, especially hematite (α-Fe2O3) and magnetite (Fe3O4) have attained substantial research interest in various applications of green and sustainable energy harnessing owing to their exceptional opto-magneto-electrical characteristics and non-toxicity. In this study, we synthesized high-purity hematite and magnetite nanoparticles from a facile top-down approach by employing a high-energy ball mill followed by ultrasonication. A systematic investigation was then carried out to explore the structural, morphological, thermal, optoelectrical, and magnetic properties of the synthesized samples. The experimental results from scanning electron microscopy and X-ray diffraction corroborated the formation of highly crystalline hematite and magnetite nanoparticles with average sizes of ~80 nm and ~50 nm, respectively. Thermogravimetric analysis revealed remarkable results on the thermal stability of the newly synthesized samples. The optical studies confirmed the formation of a single-phase compound with the bandgaps dependent on the size of the nanoparticles. The electrochemical studies that utilized cyclic voltammetry and electrochemical impedance spectroscopy techniques verified these iron oxide nanoparticles as electroactive species which can enhance the charge transfer process with high mobility. The hysteresis curves of the samples revealed the paramagnetic behavior of the samples with high values of coercivity. Thus, these optimized materials can be recommended for use in future optoelectronic devices and can prove to be potential candidates in the advanced research of new optoelectronic materials for improved energy devices

Photo-catalytic pretreatment of biomass for anaerobic digestion using visible light and Nickle oxide (NiOx) nanoparticles prepared by sol gel method

International audienc

Current research and development status of corrosion behavior of automotive materials in biofuels

The world’s need for energy is increasing with the passage of time and the substantial energy demand of the world is met by fossil fuels. Biodiesel has been considered as a replacement for fossil fuels in automotive engines. Biodiesels are advantageous because they provide energy security, they are nontoxic, renewable, economical, and biodegradable and clean sources of energy. However, there are certain disadvantages of biodiesels, including their corrosive, hygroscopic and oxidative natures. This paper provides a review of automotive materials when coming into contact with biodiesel blended fuel in terms of corrosion. Biodiesels have generally been proved to be corrosive, therefore it is important to understand the limits and extents of corrosion on different materials. Methods generally used to find and calculate corrosion have also been discussed in this paper. The reasons for the occurrence of corrosion and the subsequent problems because of corrosion have been presented. Biodiesel production can be carried out by different feedstocks and the studies which have been carried out on these biodiesels have been reviewed in this paper. A certain number of compounds form on the surface of materials because of corrosion and the mechanism behind the formation of these compounds along with the characterization techniques generally used is reviewed

Current research and development status of corrosion behavior of automotive materials in biofuels

The world’s need for energy is increasing with the passage of time and the substantial energy demand of the world is met by fossil fuels. Biodiesel has been considered as a replacement for fossil fuels in automotive engines. Biodiesels are advantageous because they provide energy security, they are nontoxic, renewable, economical, and biodegradable and clean sources of energy. However, there are certain disadvantages of biodiesels, including their corrosive, hygroscopic and oxidative natures. This paper provides a review of automotive materials when coming into contact with biodiesel blended fuel in terms of corrosion. Biodiesels have generally been proved to be corrosive, therefore it is important to understand the limits and extents of corrosion on different materials. Methods generally used to find and calculate corrosion have also been discussed in this paper. The reasons for the occurrence of corrosion and the subsequent problems because of corrosion have been presented. Biodiesel production can be carried out by different feedstocks and the studies which have been carried out on these biodiesels have been reviewed in this paper. A certain number of compounds form on the surface of materials because of corrosion and the mechanism behind the formation of these compounds along with the characterization techniques generally used is reviewed

Synthesis and Characterization of Composites with Y-Hexaferrites for Electromagnetic Interference Shielding Applications

The current research is focused on the chemical process and characterization of Co-based Y-type hexaferrite, electrochemically active polypyrrole doped with dodecylbenzene sulphonicacid (PPy-DBSA) and their composites. The microemulsion technique was used to produce hexaferrite with the formula Sr2Co2Fe12O22. The resistivity of pure ferrite specimens was 103 ohm-cm, which was lower than the 106 ohm-cm resistivity of the monomer utilized in the polymerization operation. As the temperature increases, the DC resistance decreases, revealing the specimens’ semiconductor nature. The cole-cole plots have been used to assess whether significant grain boundaries were involved in the dielectric relaxation process. By increasing the frequency, the electrochemical performance of all specimens was enhanced. Using the rate equation, ionic conductivity demonstrates that polarons are responsible for conduction. Because of the characteristics of the polymer PPY-conducting DBSA, the composites PPY/DBSA + Sr2Co2Fe12O22 exhibit a higher dielectric loss of 35 at 1 MHz. This specimen is perfect for electrical radiation shielding (EMI).These ferrites are widely used as permanent magnets, in microwave devices, high-density perpendicular media, and rigid disk media without lubricant and protective layers

Synthesis and Characterization of Composites with Y-Hexaferrites for Electromagnetic Interference Shielding Applications

The current research is focused on the chemical process and characterization of Co-based Y-type hexaferrite, electrochemically active polypyrrole doped with dodecylbenzene sulphonicacid (PPy-DBSA) and their composites. The microemulsion technique was used to produce hexaferrite with the formula Sr2Co2Fe12O22. The resistivity of pure ferrite specimens was 103 ohm-cm, which was lower than the 106 ohm-cm resistivity of the monomer utilized in the polymerization operation. As the temperature increases, the DC resistance decreases, revealing the specimens’ semiconductor nature. The cole-cole plots have been used to assess whether significant grain boundaries were involved in the dielectric relaxation process. By increasing the frequency, the electrochemical performance of all specimens was enhanced. Using the rate equation, ionic conductivity demonstrates that polarons are responsible for conduction. Because of the characteristics of the polymer PPY-conducting DBSA, the composites PPY/DBSA + Sr2Co2Fe12O22 exhibit a higher dielectric loss of 35 at 1 MHz. This specimen is perfect for electrical radiation shielding (EMI).These ferrites are widely used as permanent magnets, in microwave devices, high-density perpendicular media, and rigid disk media without lubricant and protective layers

A Brief Assessment on Recent Developments in Efficient Electrocatalytic Nitrogen Reduction with 2D Non-Metallic Nanomaterials

In recent years, the synthesis of ammonia (NH3) has been developed by electrocatalytic technology that is a potential way to effectively replace the Haber–Bosch process, which is an industrial synthesis of NH3. Industrial ammonia has caused a series of problems for the population and environment. In the face of sustainable green synthesis methods, the advantages of electrocatalytic nitrogen reduction for synthesis of NH3 in aqueous media have attracted a great amount of attention from researchers. This review summarizes the recent progress on the highly efficient electrocatalysts based on 2D non-metallic nanomaterial and provides a brief overview of the synthesis principle of electrocatalysis and the performance measurement indicators of electrocatalysts. Moreover, the current development of N2 reduction reaction (NRR) electrocatalyst is discussed and prospected

Chitosan-Induced Physiological and Biochemical Regulations Confer Drought Tolerance in Pot Marigold (<i>Calendula officinalis</i> L.)

Severe water stress conditions limit growth and development of floricultural crops which affects flower quality. Hence, development of effective approaches for drought tolerance is crucial to limit recurring water deficit challenges. Foliar application of various plant growth regulators has been evaluated to improve drought tolerance in different floricultural crops; however, reports regarding the role of chitosan (Ci) on seasonal flowers like calendula are still scant. Therefore, we evaluated the role of Ci foliar application on morphological, physiological, biochemical, and anatomical parameters of calendula under water stress conditions. Different doses of Ci (0, 2.5, 5, 7.5, 10 mg L−1) were applied through foliar application to evaluate their impact in enhancing growth and photosynthetic pigments of calendula. The optimized Ci level of 7.5 mg L−1 was further evaluated to study mechanisms of water stress tolerance in calendula. Ci application significantly increased biomass and pigments in calendula. Ci (7.5 mg L−1) resulted in increased photosynthetic rate (72.98%), transpiration rate (62.11%), stomatal conductance (59.54%), sub-stomatal conductance (20.62%), and water use efficiency (84.93%). Furthermore, it improved catalase, guaiacol peroxidase, and superoxide dismutase by 56.70%, 64.94%, and 32.41%, respectively. These results highlighted the significance of Ci in inducing drought tolerance in pot marigold

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The development of $$\hbox {TiO}_{2}$$–rGO nanocomposite-based photoanode is an efficient way to enhance the power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). $$\hbox {TiO}_{2}$$–rGO nanocomposite has been synthesized for the modified photoanode of DSSCs. GO has been synthesized by modified Hummer’s method, and rGO was achieved by two more steps. $$\hbox {TiO}_{2}$$ nanoparticles have been synthesized by the sol–gel approach followed by composition with rGO. The $$\hbox {TiO}_{2}$$–rGO nanocomposites were analyzed by Field-Emission Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD), UV–Vis Spectroscopy, and IV measurements. The as synthesized $$\hbox {TiO}_{2}$$–rGO nanocomposite-based photoanode showed a higher PCE than pure $$\hbox {TiO}_{2}$$ nanoparticles-based photoanode. Moreover, $$\hbox {TiO}_{2}$$–rGO nanocomposite-based photoanode presented enhanced efficiency of 4.09% in DSSCs because rGO has better charge collection ability, which is more convenient to reduce the electron recombination rate