13 research outputs found
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Fast-Response Micro-Phototransistor Based on MoS2/Organic Molecule Heterojunction
Over the past years, molybdenum disulfide (MoS2) has been the most extensively studied two-dimensional (2D) semiconductormaterial. With unique electrical and optical properties, 2DMoS2 is considered to be a promising candidate for future nanoscale electronic and optoelectronic devices. However, charge trapping leads to a persistent photoconductance (PPC), hindering its use for optoelectronic applications. To overcome these drawbacks and improve the optoelectronic performance, organic semiconductors (OSCs) are selected to passivate surface defects, tune the optical characteristics, and modify the doping polarity of 2D MoS2. Here, we demonstrate a fast photoresponse in multilayer (ML) MoS2 by addressing a heterojunction interface with vanadylphthalocyanine (VOPc) molecules. The MoS2/VOPc van der Waals interaction that has been established encourages the PPC effect in MoS2 by rapidly segregating photo-generated holes, which move away from the traps of MoS2 toward the VOPc molecules. The MoS2/VOPc phototransistor exhibits a fast photo response of less than 15 ms for decay and rise, which is enhanced by 3ordersof magnitude in comparison to that of a pristine MoS2-based phototransistor (seconds to tens of seconds). This work offers a means to realize high-performance transition metal dichalcogenide (TMD)-based photodetection with a fast response speed
Assessment of bias in morphological identification of carnivore scats confirmed with molecular scatology in north-eastern Himalayan region of Pakistan
Scats are often used to study ecological parameters of carnivore species. However, field identification of carnivore scats, based on their morphological characteristics, becomes difficult if many carnivore species are distributed in the same area. We assessed error rates in morphological identification of five sympatric carnivores’ scats in north-eastern Himalayan region of Pakistan during 2013–2017. A sample of 149 scats were subjected to molecular identification using fecal DNA. We used a confusion matrix to assess different types of errors associated with carnivore scat identification. We were able to amplify DNA from 96.6% (n = 144) of scats. Based on field identification of carnivore scats, we had predicted that out of 144 scats: 11 (7.6%) scats were from common leopard, 38 (26.4%) from red fox, 29 (20.1%) from Asiatic jackal, 37 (25.7%) from yellow throated martin, 14 (9.7%) from Asian palm civet and 15 (10.4%) from small Indian civet. However, molecular identification revealed and confirmed nine were scats (6.24%) from common leopard, 40 (27.8 %) from red fox, 21 (14.6%) from Asiatic jackal, 45 (31.25%) from Asian palm civet, 12 (8.3%) scats from small Indian civet, while 11 scats (7.6%) were found from Canis lupus Spp., three (2%) from dog, one (0.7 %) scat sample from porcupine, and two (1.4%) from rhesus monkey. Misidentification rate was highest for Asian palm civet (25.7%), followed by red fox (11.1%) and Asiatic jackal (9.7%) but least for common leopard scats (4.2%). The results specific to our study area concur with previous studies that have recommended that carnivore monitoring programs utilize molecular identification of predator scats. Using only morphological identification of scats can be misleading and may result in wrong management decisions
Crystal engineering with pyrazolyl-thiazole derivatives: structure-directing role of π-stacking and σ-hole interactions
The synthesis and X-ray characterization of 1-(2-(3-(4-bromophenyl)-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)-4-methylthiazol-5-yl)ethanone (7), ethyl 2-(5-(4-bromophenyl)-3-(4-chlorophenyl)-4,5-dihydropyrazol-1-yl)thiazole-4-carboxylate (8) and 2-(5-(4-chlorophenyl)-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl)-N′-(2-hydroxy-3-methoxybenzylidene)thiazole-4-carbohydrazide (10) are described in this manuscript. The structure-directing role of a variety of noncovalent interactions has been analyzed energetically using DFT calculations and Hirshfeld surface analysis. Moreover, the existence and importance of halogen and chalcogen bonding interactions have been analyzed by using the quantum theory of atoms in molecules and the noncovalent interaction index (NCIplot).Fil: Ahmed, Muhammad Naeem. University of Azad Jammu and Kashmir; PakistánFil: Madni, Murtaza. Quaiad-i-Azam University; PakistánFil: Anjum, Shaista. University of Azad Jammu and Kashmir; PakistánFil: Andleeb, Saiqa. University of Azad Jammu and Kashmir; PakistánFil: Hameed, Shahid. Quaiad-i-Azam University; PakistánFil: Khan, Abdul Majeed. Federal Urdu University of Arts; Pakistán. University Road; PakistánFil: Ashfaq, Muhammad. University of Sargodha; PakistánFil: Tahir, Muhammad Nawaz. University of Sargodha; PakistánFil: Gil, Diego Mauricio. Universidad Nacional de Tucumán. Instituto de BiotecnologÃa Farmacéutica y Alimentaria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Instituto de BiotecnologÃa Farmacéutica y Alimentaria; Argentina. Universidad Nacional de Tucumán. Facultad de BioquÃmica, QuÃmica y Farmacia. Instituto de QuÃmica Orgánica; ArgentinaFil: Frontera, Antonio. Universidad de las Islas Baleares; Españ
Production, functional stability, and effect of rhamnolipid biosurfactant from Klebsiella sp. on phenanthrene degradation in various medium systems
The present study investigated the stability and efficacy of a biosurfactant produced by Klebsiella sp. KOD36 under extreme conditions and its potential for enhancing the solubilization and degradation of phenanthrene in various environmental matrices. Klebsiella sp. KOD36 produced a mono-rhamnolipids biosurfactant with a low critical micelle concentration (CMC) value. The biosurfactant was stable under extreme conditions (60 °C, pH 10 and 10% salinity) and could lower surface tension by 30% and maintained an emulsification index of > 40%. The emulsion index was also higher (17–43%) in the presence of petroleum hydrocarbons compared to synthetic surfactant Triton X-100. Investigation on phenanthrene degradation in three different environmental matrices (aqueous, soil-slurry and soil) confirmed that the biosurfactant enhanced the solubilization and biodegradation of phenanthrene in all matrices. The high functional stability and performance of the biosurfactant under extreme conditions on phenanthrene degradation show the great potential of the biosurfactant for remediation applications under harsh environmental conditions
Female Oppression and Marginalization in Ice Candy Man by Sidhwa and the Holy Woman by Shahraz
How women are marginalized during the partition and after the partition is the major theoretical concern of this research. The present research reveals how Sidhwa and Shahraz address the gender oppression in Ice Candy Man and The Holy Woman respectively. Different researchers also argues that both writers describe the subjection of women to rape, conversion, forced marriages and various sexual abuses during partition and in the days of peace. The social structure of our society regards women as the honor of family. In case of marginalization she suffers the sexual violence; she gets profaned, resulting in the honor killing of the family. Sidhwa and Shahraz represent this oppression, marginalization, and violence as the shameful event. Shahraz and Sidhwa’s writings shows how the gender oppression work through their bodies. The selected novels of both writers show how the women are oppressed, marginalized, controlled, and exploited by the men under the shade of cultural, social, and religious traditions. This research will expose both the violent and subtle ways in which patriarchy repress the female to control in Pakistani society. The main focus of this research is to show how the works of these two female writers are critically examined to understand their role in exploring the issues of women that they face in this patriarchal society through the literary medium. Keywords: women, oppression, marginalization, patriarchy, religious, social, tradition
Tuning of electrical properties of CVD grown graphene by surface doping with organic molecules
Tailoring the charge carriers of two-dimensional (2D) materials is essential for high performance optoelectronic devices. The surface transfer doping by adsorption of molecules on 2D crystals is an attractive technique to tune the properties. Here, we study the change in the electronic transport properties of monolayer graphene (MLG) by surface doping with two different types of molecules. An effect of methyl isobutyl ketone (MIBK) and chlorobenzene molecular doping on the carrier concentration and electrical conductivity of chemical vapor deposition(CVD)-grown MLG was carried out by Raman spectroscopy and electrical transport measurement. The shifting of Raman peaks toward higher wave number and shifting of Dirac points toward positive gate voltage confirmed that the surface doping of graphene with MIBK and chlorobenzene molecules induced holes doping effect. The molecular doping approach significantly improved the carrier concentration of CVD grown MLG, which is a promising result. Our study will be useful for understanding as well as improvement of graphene based electronic device research
Range contraction of snow leopard (Panthera uncia).
Snow Leopard (Panthera uncia) is native to mountain ranges of Central and South Asia, where it occurs from 3,000-4500 m elevation. The species is enlisted as "Endangered" by IUCN and its populations are reportedly declining. In the current study, we compared the past and current distribution ranges of the species using spatial analysis. We used Quantum Geographical Information System (QGIS) software to reconstruct and quantify its past distribution range and compare with its current one. Snow leopard was found more widely distributed in the past having a distribution range of approximately 10.47 million km2 against the current 3.20 million km2. Range contraction of the species approximates 69%. A total of 719 terrestrial protected areas of Asia (out of total 7209) had this species in the past whereas at current, only 311 protected areas support this species. The results emphasize escalating conservation efforts to save its remaining distribution range
Evaluating toxicity impacts of environmental exposed chromium on small Indian mongoose (Urva auropunctatus) hematological, biochemical and histopathological functioning
Sub-lethal toxic impacts of chromium on hematological, biochemical and histological parameters were analyzed in the female small Indian mongoose (Urva auropuctatus) residing contaminated environment of tannery industry. Chromium bioaccumulation in the blood, liver and kidney tissue of the exposed mongooses was found elevated compared to the control mongooses' tissues. Total body weight (75.7%), liver weight (83.6%) as well as HSI (68.1%), RSI (86.2%) and the platelets counts (59.7%) were found significantly elevated, with significantly reduced RBCs (59.6%), and WBCs (64%). LFT and RFT were also found abnormal, moreover, the histopathological injuries had been distinct inside the kidney (>75%) and hepatic (>75%) tissues of exposed animals. Shrinkage and vacuolization (> 75%) inside the hepatocyte expanded sinusoidal spaces and nuclear pyknosis (>75%) was evident within the hepatic tissue. Hypertrophy of epithelial cells of renal tubules and inter-renal cells of the head kidney with a reduction in tubular lumens (>75%) and vacuolization of tubules were witnessed within the kidney section. Atrophy inside the kidney inter-renal cells, glomeruli compression within the Bowman's capsules (>75%) following the necrosis in hematopoietic tissues were found in exposed animals. The present findings indicate that chronic exposure to chromium induces severe anemia, decreased serum protein concentration, hepatic and renal tissue histopathology, impairing the vital capabilities of liver, metabolic regulation, excretion, and stress homeostasis maintenance of which within the long-run may posture a severe risk to animal well-being then distress their inhabitants. (C) 2020 Elsevier Ltd. All rights reserved
Fast-Response Micro-Phototransistor Based on MoS<sub>2</sub>/Organic Molecule Heterojunction
Over the past years, molybdenum disulfide (MoS2) has been the most extensively studied two-dimensional (2D) semiconductormaterial. With unique electrical and optical properties, 2DMoS2 is considered to be a promising candidate for future nanoscale electronic and optoelectronic devices. However, charge trapping leads to a persistent photoconductance (PPC), hindering its use for optoelectronic applications. To overcome these drawbacks and improve the optoelectronic performance, organic semiconductors (OSCs) are selected to passivate surface defects, tune the optical characteristics, and modify the doping polarity of 2D MoS2. Here, we demonstrate a fast photoresponse in multilayer (ML) MoS2 by addressing a heterojunction interface with vanadylphthalocyanine (VOPc) molecules. The MoS2/VOPc van der Waals interaction that has been established encourages the PPC effect in MoS2 by rapidly segregating photo-generated holes, which move away from the traps of MoS2 toward the VOPc molecules. The MoS2/VOPc phototransistor exhibits a fast photo response of less than 15 ms for decay and rise, which is enhanced by 3ordersof magnitude in comparison to that of a pristine MoS2-based phototransistor (seconds to tens of seconds). This work offers a means to realize high-performance transition metal dichalcogenide (TMD)-based photodetection with a fast response speed