| 1. |
- Hussain, Iftikhar, et al.
(författare)
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Modified KBBF-like Material for Energy Storage Applications : ZnNiBO3(OH) with Enhanced Cycle Life
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:6, s. 8025-8035
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Tidskriftsartikel (refereegranskat)abstract
- Not only are new and novel materials sought for electrode material development, but safe and nontoxic materials are also highly being intensively investigated. Herein, we prepare ZnNiBO3(OH) (ZNBH), a modified and Be-free KBe2BO3F2 (KBBF) family member as an effective electrode material. The novel ZNBH resembles the KBBF structure but with reinforced structure and bonding, in addition to well-incorporated conductive metals benefiting supercapacitor applications. The enhanced electronic properties of ZNBH are further studied by means of density functional theory calculations. The as-prepared ZNBH electrode material exhibits a specific capacity of 746 C g(-1) at a current density of 1 A g(-1). A hybrid supercapacitor (HSC) device is fabricated and successfully illuminated multiple color LEDs. Interestingly, even after being subjected to long charge-discharge for 10 000 cycles, the ZNBH//AC HSC device retains 97.2% of its maximum capacity, indicating the practicality of ZNBH as an electrode material.
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| 2. |
- Mahmood, Rashid, et al.
(författare)
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Assessment of antidiabetic potential and phytochemical profiling of Rhazya stricta root extracts
- 2020
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Ingår i: BMC Complementary Medicine and Therapies. - : Springer Nature. - 2662-7671. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Diabetes mellitus is a chronic disease characterized by hyperglycemia that may occur due to genetic, environmental or lifestyle factors. Natural remedies have been used to treat diabetes since long and many antidiabetic compounds of varied efficacies have been isolated from medicinal plants. Rhazya stricta has been used for decades for the treatment of diabetes mellitus and associated ailments. Considering the folkloric use of R. stricta against diabetes, it was aimed to investigate the effectiveness of its root extracts against diabetes through in vitro assays and in vivo studies using animal model along with phytochemical profiling through GCMS. Methods: Various fractions of Rhazya stricta obtained through column chromatography were evaluated for a variety of assays including a-glucosidase, Dipeptidyl peptidase-IV (DPP-IV), beta-secretase and Glucagon-like peptide-1 (GLP-1) secretion studies. For the in vivo studies the alloxan-induced diabetic mice were treated with root extracts and blood glucose levels, HbA1C, and other biochemical markers along with the histological study of the liver were done. The phytochemical identification was performed using an Agilent 7890B GC coupled to a 7010 Triple Quadrupole (MS/MS) system. GraphPad Prism software version 5.01 was used for statistical analysis. Results: Majority of the extract fractions showed excellent results against diabetes by inhibiting enzymes DPP-IV (Up to 61%) and beta-secretase (Up to 83%) with IC50s 979 pg/ml and 169 mu g/ml respectively with increase in the GLP1 secretion. The results of in vivo studies indicated a marked reduction in blood glucose and HbA1c levels along with positive effects on other parameters like lipid profile, liver functions and renal functions of extract-treated mice as compared to control. The histological examination of the liver demonstrated hepatoprotective effects against diabetes led changes and various classes of phytochemicals were also identified through GCMS in different fractions. Conclusion: The results revealed strong antidiabetic activity of R. stricta root with the potential to protect body organs against diabetic changes. Moreover, a variety of phytochemicals has also been identified through GCMS that might be responsible for the antidiabetic potential of Rhazya stricta root.
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| 3. |
- Salman, Muhammad, et al.
(författare)
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Evaluation of Conspiracy Beliefs, Vaccine Hesitancy, and Willingness to Pay towards COVID-19 Vaccines in Six Countries from Asian and African Regions : A Large Multinational Analysis
- 2022
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Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Vaccination protects people from serious illness and associated complications. Conspiracy theories and misinformation on vaccines have been rampant during the COVID-19 pandemic and are considered significant drivers of vaccine hesitancy. Since vaccine hesitancy can undermine efforts to immunize the population against COVID-19 and interferes with the vaccination rate, this study aimed to ascertain the COVID-19-vaccine-related conspiracy beliefs, vaccine hesitancy, views regarding vaccine mandates, and willingness to pay for vaccines among the general population. A web-based, cross-sectional survey was conducted (April-August 2021) among the adult population in six countries (Pakistan, Saudi Arabia, India, Malaysia, Sudan, and Egypt). Participants were recruited using an exponential, non-discriminate snowball sampling method. A validated self-completed electronic questionnaire was used for the data collection. All the participants responded to questions on various domains of the study instrument, including conspiracy beliefs, vaccine hesitancy, and willingness to pay. The responses were scored according to predefined criteria and stratified into various groups. All data were entered and analyzed using SPSS version 22. A total of 2481 responses were included in the study (Pakistan 24.1%, Saudi Arabia 19.5%, India 11.6%, Malaysia 8.1%, Sudan 19.3%, and Egypt 17.3%). There was a preponderance of participants <= 40 years old (18-25 years: 55.8%, 26-40 years: 28.5%) and females (57.1%). The average score of the COVID-19 vaccine conspiracy belief scale (C19V-CBS) was 2.30 +/- 2.12 (median 2; range 0-7). Our analysis showed that 30% of the respondents were found to achieve the ideal score of zero, indicating no conspiracy belief. The mean score of the COVID-19 vaccine hesitancy scale (C19V-HS) was 25.93 +/- 8.11 (range: 10-50). The majority (45.7%) had C19V-HA scores of 21-30 and nearly 28% achieved a score greater than 30, indicating a higher degree of hesitancy. There was a significant positive correlation between conspiracy beliefs and vaccine hesitancy (Spearman's rho = 0.547, p < 0.001). Half of the study population were against the vaccine mandate. Respondents in favor of governmental enforcement of COVID-19 vaccines had significantly (p < 0.001) lower scores on the C19V-CBS and C19V-HS scale. Nearly 52% reported that they would only take vaccine if it were free, and only 24% were willing to pay for COVID-19 vaccines. A high prevalence of conspiracy beliefs and vaccine hesitancy was observed in the targeted countries. Our findings highlight the dire need for aggressive measures to counter the conspiracy beliefs and factors underlying this vaccine hesitancy.
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| 4. |
- Salman, Muhammad, et al.
(författare)
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Trajectory of COVID-19 vaccine hesitancy post-vaccination and public's intention to take booster vaccines : A cross-sectional analysis
- 2023
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Ingår i: Human Vaccines & Immunotherapeutics. - : Taylor & Francis. - 2164-5515 .- 2164-554X. ; 19:2
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Tidskriftsartikel (refereegranskat)abstract
- Vaccine hesitancy (VH) is not a new phenomenon in Pakistan and is regarded as one of the primary causes of unsatisfactory vaccination campaigns. This study determined post-vaccination COVID-19 VH, factors influencing COVID-19 vaccine uptake, and public's intent to receive booster vaccinations. A cross-sectional study was conducted among adult population of Lahore, Pakistan. Participants were recruited via convenience sampling between March and May 2022. SPSS version 22 was used for the data analysis. A total of 650 participants were included in the study (age = 28.1 & PLUSMN; 9.7 years; male-to-female ratio nearly 1: 1). The majority of participants received Sinopharm followed by Sinovac vaccine. The top three reasons of vaccine uptake were "only vaccinated individuals are allowed at the workplace, and educational institutes" (Relative importance index (RII) = 0.749), "only vaccinated people are allowed to go to markets, malls and other public places" (RII = 0.746), and "protect myself from the infection" (RII = 0.742). The mean COVID-19 VH score was 24.5 & PLUSMN; 6.2 (95% CI 23.9-24.9), with not being pro-vaccines and poor economic status were the significant predictors of COVID-19 vaccine hesitancy among immunized individuals (p < .05). Acceptance of booster vaccines was negatively associated with younger age and a lower level of education. Furthermore, being pro-vaccine was associated with a greater likelihood of accepting booster vaccines (p = .001). The Pakistani public continues to express VH toward COVID-19 vaccines. Therefore, aggressive measures must be taken to combat the community factors that contribute to it.
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| 5. |
- Anikina, Ekaterina, et al.
(författare)
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Elucidating hydrogen storage properties of two-dimensional siligraphene (SiC8) monolayers upon selected metal decoration
- 2020
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Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry (RSC). - 2398-4902. ; 4:11, s. 5578-5587
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Tidskriftsartikel (refereegranskat)abstract
- Density functional theory calculations with dispersion corrections were employed to investigate the hydrogen (H-2) adsorptive properties of siligraphene (SiC8), pristine and decorated with selected alkali (Li, Na, and K) and alkaline-earth (Be, Mg, and Ca) metals. We found that all the considered metals (Me), except Mg and Be, bind strongly to SiC8 even at high doping concentrations (SiC8Me2) by donating a major portion of their valence electrons to SiC8. Ab initio molecular dynamics (AIMD) simulations confirmed the thermal stabilities of SiC8Me2 (Me = Li, Na, K, Ca) at 300 K. We showed that Li, Na, and Ca-doped SiC8 adsorbed multiple H-2 molecules with binding energies (E-bind) at least two times stronger than that of the pristine SiC8 (Epristinebind = -70 meV per H-2). Overall, both SiC8Li2 and SiC8Ca2 adsorbed two and four H-2 molecules per metal adatom, respectively, having E-bind within the desirable range for an effective adsorption/desorption process. The resulting gravimetric densities of SiC8Li2 and SiC8Ca2 were 5.5 wt% and 7.3 wt%, respectively, surpassing the U.S. Department of Energy's 2025 goal of 5.5 wt%. The estimated H-2 desorption temperatures exceed substantially the boiling point of liquid nitrogen, confirming the potential of light metal decorated SiC8 as a promising material for H-2 storage.
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| 6. |
- Anikina, Ekaterina, et al.
(författare)
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High-capacity reversible hydrogen storage properties of metal-decorated nitrogenated holey graphenes
- 2022
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Ingår i: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 47:19, s. 10654-10664
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Tidskriftsartikel (refereegranskat)abstract
- Motivated by the need for an effective way of storing hydrogen (H-2), a promising energy carrier, we have performed density functional theory (DFT) calculations with different van der Waals corrections coupled with the statistical thermodynamic analysis and ab initio molecular dynamics (AIMD) on the light-metal decorated nitrogenated holey graphene (C2N) monolayers. We have found that the decoration by selected light metals (Na, Mg, Ca) improves the H2 adsorption on the C2N to the desired levels (> 150 meV/H-2). Moreover, the metal dopants strongly bonded with C2N even at higher doping concentrations, which invalidates the metal clusters formation. Among considered metals, Na and Mg resulted in H-2 storage capacities of 5.5 and 6.9 wt%, respectively, which exceed the target set by the U.S. Department of Energy's for 2025. Thermodynamic analysis and the AIMD simulations were employed to investigate the H-2 sorption at varied conditions of temperature and pressure for practical applications.
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| 7. |
- Anikina, Ekaterina, et al.
(författare)
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Tunning Hydrogen Storage Properties of Carbon Ene-Yne Nanosheets through Selected Foreign Metal Functionalization
- 2020
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 124:31, s. 16827-16837
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we have employed density functional theory with a range of van der Waals corrections to study geometries, electronic structures, and hydrogen (H-2) storage properties of carbon ene-yne (CEY) decorated with selected alkali (Na, K) and alkaline-earth metals (Mg, Ca). We found that all metals, except Mg, bind strongly by donating a major portion of their valence electrons to the CEY monolayers. Thermal stabilities of representative systems, Ca-decorated CEY monolayers, have been confirmed through ab initio molecular dynamics simulations (AIMD). We showed that each metal cation adsorbs multiple H-2 with binding energies (E-bind) considerably stronger than on pristine CEY. Among various metal dopants, Ca stands out with the adsorption of five H-2 per each Ca having E-bind values within the desirable range for effective adsorption/desorption process. The resulting gravimetric density for CEY@Ca has been found around 6.0 wt % (DFT-D3) and 8.0 wt % (LDA), surpassing the U.S. Department of Energy's 2025 goal of 5.5 wt %. The estimated H-2 desorption temperature in CEY@Ca exceeds substantially the boiling point of liquid nitrogen, which confirms its potential as a practical H-2 storage medium. We have also employed thermodynamic analysis to explore the H-2 adsorption/desorption mechanism at varied conditions of temperature and pressure for real-world applications.
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| 8. |
- Aslam, Muhammad Kashif, et al.
(författare)
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How to avoid dendrite formation in metal batteries : Innovative strategies for dendrite suppression
- 2021
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 86
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Forskningsöversikt (refereegranskat)abstract
- With increasing the diversity of electronic/electric appliances and large-scale energy storage systems, highenergy-density based device technology has been in great demand. Meanwhile, for developing of high-voltage and high-capacity cathode, the use of metals including lithium (Li), sodium (Na), potassium (K), or zinc (Zn) is quite impressive to replace the traditional anodes with low capacity upper limit such as graphite, silicon carbon, and hard carbon which is considered as "holy grail" strategy to explore high-energy density systems. However, these so-called metal batteries (MBs) also face many thorny issues including high anode reactivity, dendritic growth, and high safety risks. Among all these muddle, the dendrite growth is quite sever issue and has attracted much attention of many recognized materials scientist and battery researchers. The formation of dendrite increase the surface area of metal anodes, induce the rupture and reconstruction of solid electrolyte interphase (SEI) film, which is likely to accelerate the excessive consumption of electrolyte and the formation of dead metals. Consequently, battery lose its capability and short circuit produced which causes serious safety issues. Therefore, it is badly needed to inhibit or even eliminate the formation of dendrites during the repeated charge and discharge process to find advanced and fast battery technology. In this review, we summarize the basic mechanistic theoretical models about dendrites formation and their effects on the battery performance. Moreover, we recapitulate the reported literature about dendrites concept and their solution from battery invention to its modernism for smart electric appliances and zero emission electric vehicles. Besides, perspective of interface energy/volume stress, several innovative strategies for restraining, regulating and eliminating dendrites are also part of this review. Finally, perspectives conclusions for the development of MBs about dendrite level are given for the progress of future battery science.
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| 9. |
- Boota, Muhammad, et al.
(författare)
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MXene binder stabilizes pseudocapacitance of conducting polymers
- 2021
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 9:36, s. 20356-20361
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Tidskriftsartikel (refereegranskat)abstract
- Conducting polymers (CPs) are by far the most studied organic materials for supercapacitors. Yet, their structural instability stemming from volumetric expansion/contraction during charge/discharge results in capacitance loss after moderate cycling that limits their applications. Here, we show that the remarkable cycling stability, capacitance, and rate performance can be achieved by replacing conventional electrode additives (carbon black or insulating polymer binder) with titanium carbide (Ti3C2Tx) MXene. Using polyaniline (PANI) as a model system, an addition of only 15 wt% of Ti3C2Tx MXene binder delivered remarkable capacitance retention of 96% after 10 000 cycles at 50 mV s(-1) and high-rate capability with a capacitance of 434 F g(-1). Using density functional theory (DFT) calculations, we show that, unlike insulating polymer binders, surface groups of MXene bond to PANI with a significantly high binding energy (up to -2.11 eV) via a charge transfer mechanism. This is one of the key mechanisms to achieve a high electrochemical performance of the CP-based electrodes when MXene is used as a binder. We expect that a similar approach can be used for stabilizing other organic electrode materials.
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| 10. |
- Deshpande, Swapnil, et al.
(författare)
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Binding and optical characteristics of polycyclic aromatic hydrocarbons and their nitroderivatives adsorbed on the C3N monolayer
- 2022
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry. - 1144-0546 .- 1369-9261. ; 46:5, s. 2245-2258
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Tidskriftsartikel (refereegranskat)abstract
- Carbon-nitrogen based two dimensional frameworks have attracted significant attention due to their great potential for environmental applications. Among the g-CxNy family, the C3N monolayer (ML) is one of the promising candidates, which exhibits semiconducting behavior. The structural, electronic and optical properties of the polycyclic aromatic hydrocarbons (PAHs) and their nitroderivatives adsorbed on the C3N ML have been investigated using first principles calculations. We chose six representative molecules from the PAH family, benzene (B), anthracene (A), and benzo[a]pyrene (BaP), and their nitroderivatives, nitrobenzene (NB), 9-nitroanthracene (NA), and 6-nitro-benzo[a]pyrene (NBaP). These molecules are severely affecting human beings and aquatic systems. The optimal adsorption orientation of these molecules on the C3N ML is determined and the adsorption energies (E-ads) are calculated. The E-ads of these PAH molecules with C3N ML are found to be higher than that of graphene. The PAH molecules with the nitro group show higher E-ads as compared to that of molecules without the nitro group. Further, we have checked the implicit water solvation effect on the adsorption behavior of PAHs on the C3N ML. In a water solvent, E-ads further increases. The energy gap of the C3N ML is sensitive to the adsorption of these nitroderivatives of the PAH molecules, which implies the possibility of its use as a sensor. We have noticed an increase in the calculated work function upon the adsorption of PAH molecules which further explains the affinity of the C3N ML towards these molecules. The static dielectric constant epsilon(1)(0) and the refractive index (n(0)) of the pristine C3N ML are 4.24 and 2.06, respectively. Adsorption of B, A and BaP molecules on C3N does not have a significant impact on the values of epsilon(1)(0) and n(0). But adsorption of their nitroderivatives shows a notable increase in the values of epsilon(1)(0) and n(0). We believe that our results could trigger further theoretical and experimental work towards constructing highly sensitive nanosensors and optical devices to detect PAHs.
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