PUBLIC DEBT AND ECONOMIC GROWTH IN PAKISTAN: A REASSESSMENT

This study examined the effect of public debt on economicgrowth for Pakistan over the period 1972 to 2012. Autoregressivedistributed lag (ARDL) bounds testing procedure was applied toexplore the long and the short run liaison between public debt andeconomic growth. This study examined the effect of public debt onboth the Gross Domestic Product (GDP) and the Grass NationalProduct (GNP) unlike other studies, which examined only oneindicator of economic growth. Public debt includes both externaldebt and domestic debt. Our findings reveal a significant negativeeffect of external debt on GDP and GNP in the long run and in theshort run. Further, debt servicing is inversely influencing GDP andGNP in the short run. However, domestic debt is found to have noeffect on economic growth. This study suggests that reliance on publicdebt should be minimized as this adversely effects economic growthin Pakistan

Engineered nanoparticles for removal of pollutants from wastewater: Current status and future prospects of nanotechnology for remediation strategies

Significant aspects of the world\u27s water scenario, primarily associated with global population growth and climate change, necessitate new technology implementation to ensure a supply of drinking water and prevent global water contamination. In light of this, the incorporation of state-of-the-art nanotechnology in conventional process engineering opens new paths for improved wastewater treatment technologies. Nano-based materials techniques, such as disinfection, desalination, sensing and monitoring, photocatalysis, membrane process, adsorption, biological treatment, coagulation/precipitation, and oxidation are discussed in this overview of current breakthroughs in nanotechnologies for removal of pollutants from wastewater. The benefits of these nano-based materials for wastewater treatment approaches, as well as the technical challenges are discussed in this review. The current state of commercialization, as well as future research opportunities in nano-based materials and technologies are highlighted. Additionally, the anticipated scientific breakthroughs, the constraints of nanotechnology for desalination processes, such as rules and regulations, and potential health risks are addressed. The regulation of nanoengineered materials and technologies used in wastewater treatment is being addressed in both Europe and United States of America

Pecking at Pecking Order Theory: Evidence from Pakistan’s Non-financial Sector

This study tests the Pecking Order Theory for the capital structure of listed firms in Pakistan. As per Pecking Order Theory in capital structure formulation, internally generated resources would have first priority, followed by debt issuance where equity is used as a last resort. In its strong form, the Pecking Order Theory sustains that equity issues would never occur, whereas in its weak form, limited amounts of issues are acceptable. The methodology adopted in this empirical study involves cross-section regressions and the testing of hypotheses stemming from the underlying theory in its strong and weak forms. A sample of capital structure of non-financial firms listed at KSE is considered from 2001 to 2008. A statistical tool of panel data regression analysis is used to test different firms’ data. The value of R2, t-test and F-Stat indicate firms in KSE supporting the weak form of pecking order theory, i.e., the option of using internal equity and debt is more preferred and a limited amount of external equity is used for reinvestment and fund raising purposes

Preparation of magnetic chitosan corn straw biochar and its application in adsorption of amaranth dye in aqueous solution

In this study, the magnetic chitosan biochar (MCB) was magnetized by chemical coprecipitation after loading chitosan with Schiff base reaction. The prepared MCB was used to remove amaranth dye in solution. The synthesized MCB was characterized to define its surface morphology and specific elements. The amaranth dye adsorption system was optimized by varying the contact time, pH, and initial concentration. The adsorption of MCB on amaranth dye was measured in a wide pH range. According to Zeta potential, the surface of MCB was positively charged in the acidic pH region, which was more conducive to the adsorption of anionic amaranth dye. In addition, the adsorption data was fitted with the pseudo-first-order model and Langmuir adsorption model and the maximum adsorption capacity reached 404.18 mg/g. The adsorption efficiency of MCB was still above 95% after three cycles of adsorption and desorption. The removal percentage in the real sample of amaranth dye by MCB was within 94.5–98.6% and the RSD was within 0.14–1.08%. The MCB adsorbent with advantages of being easy to prepare, easy to separate from solution after adsorption, has good adsorption performance for amaranth dye and is effective potential adsorbent to remove organic anionic dye in wastewater

Bears in Pakistan: Distribution, Population Biology and Human Conflicts

We conducted questionnaire based interviews (n = 1873) of respondents coming from 258 localities about bear tracts in northern parts of Pakistan in 2012-2014 to study Himalyan brown (U. arctos isalbellinus) and Himalayan black (U. t. laniger) bears. Brown bears were more frequent in northern latitudes (northern Chitral, Ghizer, Gilgit and Skardu), while black bears were widely distributed in southern latitudes (Battagram). Both brown and black bears are present in central latitudes (Astor, Diamir, Kohistan and Mansehra). We identified 34 populations of brown bears; a large population in the Deosai Plateau and small to very small populations in other localities. We identified 9 isolated meta-populations sharing common gene pools; 7 (Bomborat, Gias, Chowgram, Laspur-Malkov, Koshi-Palas, Phunder-Yasin, Khunjerab) very small with serious inbreeding and threat of extinction, while Deosai and Diamir-Astor populations were large but were expected to have a high level inbreeding. Black bears were present in 45 localities; larger populations in three localities of Battagram (Nagram, Rahing and Shamli). We identified 6 meta-populations of black bears; Kohistan-Batagram-Mansehra, Diamir-Astor and south Chitral meta-populations were large; but 3 other populations (Thack, Hisper-Minipin and Chasma) were small/very small, possibly having high inbreeding. Bears raid standing maize crops (regular and severe in 2 localities and irregular and severe in 6) and fruit (apricot, grape, mulberry and walnut). Average annual bears depredation of 54 cattle, 188 goat/sheep, 4 yaks, and 9 horses/donkeys/mules were reported, inflicting an economic loss of Pak Rs. 2,840,000 (US$ 28,400) to the livestock farming community. Respondents reported 4 incidences of bear attack (1 killed, 3 injured) and 2 cases of cub poaching during 2013

Ionic liquid tuned titanium dioxide nanostructures as an efficient colorimetric sensing platform for dopamine detection

Dopamine is a neurotransmitter distributed in the central and peripheral nervous system, its lower or higher production results in various pathological disorders. Various nanoparticles systems have been used in the sensing of dopamine while in the present work ionic liquid tuned titanium dioxide nanoparticles (TiO2 NPs) was first time evaluated in colorimetric detection of dopamine. TiO2 NPs have been synthesized by hydrothermal process and analyzed by different characterization techniques such as FTIR, XRD, and SEM that confirmed the desired synthesis. 1-H-3-methylimidazolium acetate (ionic liquid-a known conducting species) was prepared by the neutralization method. Colorimetric change in color from pinkish grey to reddish-brown with an increase in dopamine concentration was analyzed using a UV–Vis spectrophotometer. To optimize the protocol various parameters like nanoparticles loading, conc. of dopamine etc were optimized. The quantification and limit of detection for the proposed sensor were calculated as 2.55 × 10−7 M and 7.67 × 10−8 M respectively, and 1 × 10−8–3.6 × 10−6 M linear range with an R2 value of 0.9998. At an optimum temperature of 25 °C and at pH 12 the proposed sensor response time was just 4 min for dopamine detection. The proposed sensor has been also used for the dopamine detection in physiological solution. The proposed sensor showed good sensitivity and selectivity for dopamine sensing

Tuning tetracycline removal from aqueous solution onto activated 2:1 layered clay mineral: Characterization, sorption and mechanistic studies

© 2019 Elsevier B.V. Water pollution due to emerging contaminants (especially pharmaceuticals) is a major environmental threat which results in the development of antibiotic-resistant bacteria/resistance genes in the aquatic environment. Therefore, robust and cost-effective methods are required to address this problem. In this study, thermal activation was opted for the modification of natural bentonite clay (BC) and utilized to investigate the adsorptive removal of tetracycline (TC) from aqueous solution. The physicochemical surface properties of the raw and modified bentonite samples were also investigated. The BET analysis revealed that the thermally activated bentonite (TB) has better properties than BC. The surface area of TB was found to be more than two-fold higher compared to that of BC. The FTIR spectra exhibited the existence of Al[sbnd]OH, Si[sbnd]O and Si[sbnd]O[sbnd]Si functional groups in the samples, confirming the presence of hydrated aluminosilicate in the clay. The effects of various operating parameters were analyzed via optimization studies. The maximum monolayer adsorption capacity estimated by Langmuir model was found to be 156.7 and 388.1 mg g−1 for BC and TB, respectively. Furthermore, fixed-bed column studies were performed to get insights into the adsorption behavior of TB in a dynamic system. The mechanism of TC adsorption by TB was successfully explored

High interfacial charge separation in visible-light active Z- scheme g-C3N4/MoS2 heterojunction: Mechanism and degradation of sulfasalazine

Examination of highly proficient photoactive materials for the degradation of antibiotics from the aqueous solution is the need of the hour. In the present study, a 2D/2D binary junction GCM, formed between graphitic-carbon nitride (g-C3N4) and molybdenum disulphide (MoS2), was fabricated using facile hydrothermal method and its photo-efficacy was tested for the degradation of sulfasalazine (SUL) from aqueous solution under visible-light irradiation. Morphological analysis indicated the nanosheets arrangement of MoS2 and g-C3N4. The visible-light driven experiments indicated that 97% antibiotic was degraded by GCM-30% within 90 min which was found to be quite high than pristine g-C3N4 and MoS2 at solution pH of 6, GCM-30% dose of 20 mg, and SUL concentration of 20 mgL-1. The degradation performance of GCM-30% was selectively improved due to enhanced visible-light absorption, high charge carrier separation, and high redox ability of the photogenerated charges which was induced by the effective Z-scheme 2D/2D heterojunction formed between g-C3N4 and MoS2. The reactive radicals as determined by the scavenging study were •O2-, and h+. A detailed degradation mechanism of SUL by GCM-30% was also predicted based on the detailed examination of the band gaps of g-C3N4 and MoS2