| 1. |
- Mallhi, Tauqeer Hussain, et al.
(författare)
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Mental Health and Coping Strategies among University Staff during the COVID-19 Pandemic : A Cross-Sectional Analysis from Saudi Arabia
- 2023
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- This study examined psychological health and coping strategies among faculty and staff at a Saudi Arabian university. A web-based self-administered survey was used to assess probable anxiety, depression, post-traumatic stress disorder (PTSD), and coping strategies by using the Generalized Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Impact of Event Scale-Revised (IES-R), and Brief-COPE scale, respectively. Of 502 participants (mean age 36.04 +/- 10.32 years, male: 66.3%), 24.1% (GAD-7 >= 10) had probable anxiety. Anxiety score was significantly higher in females (p < 0.001), those with a history of COVID-19 infection (p = 0.036), and participants with less work experience (p = 0.019). Approximately 40% of participants met the criteria of probable depression, with females (p < 0.001) and participants with less experience having more depressive symptoms. Around one-fourth (27.7%) of study participants indicated probable PTSD (score +/- 33), with higher symptoms in females (p <0.001), less experienced staff (p < 0.00 1), and academic staff (p = 0.006). Correlation analysis indicated a significant positive correlation between anxiety and depression (r = 0.844, p < 0.001), anxiety and PTSD (r = 0.650, p < 0.001), and depression and PTSD (r = 0.676, p < 0.001). Active coping, religious/spiritual coping, and acceptance were common coping strategies, while substance use was the least adopted coping method among the study participants. This study indicated a high prevalence of probable psychological ailments among university staff.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Khan, Ziyauddin, et al.
(författare)
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Towards printable water-in-polymer salt electrolytes for high power organic batteries
- 2022
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Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 524
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Tidskriftsartikel (refereegranskat)abstract
- Internet-of-things which requires electronics, energy convertor and storage must be low-cost, recyclable and environmentally friendly. In the development of printed batteries, ideally all the components (electrode and electrolyte) must be printable to ensure low-cost manufacturing via printing technologies. Most of the printed batteries suffer with low power. One of the reasons is the poor ionic conductivity of the electrolyte due to the high viscosity needed for printing relatively thick layers. In the present work we have demonstrated a new class of electrolyte promising for printed organic batteries following the concept of water-in-polymer salt electrolytes (WIPSEs). These highly concentrated electrolytes of potassium polyacrylate are non-flammable, low cost and environmentally friendly. They possess high ionic conductivities (45-87 mS/cm) independent on the macroscopic viscosities varying from 7 to 33000 cP. The decoupling between ionic transport and macroscopic viscosity enables us to demonstrate organic batteries based on WIPSEs that can deliver a high and constant power (similar to 4.5 kW/kg; 7.1-11 mW/cm(2)) independent on the viscosity of the electrolytes. The tunability of the viscosity presents a prerequisite for printed technology manufacturing and compatibility with printed batteries.
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| 5. |
- Khan, Ziyauddin, et al.
(författare)
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Water-in-Polymer Salt Electrolyte for Slow Self-Discharge in Organic Batteries
- 2022
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Ingår i: Advanced Energy and Sustainability Research. - : WILEY. - 2699-9412. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- In electrochemical energy storage devices (ESDs), organic electrolytes are typically used for wide operational potential window, yet they suffer with cost, environmental, flammability issues, and low ionic conductivity when compared with water-based electrolytes. Hence, for large-scale applications that require high power and safety, presently there is no true solution. Though water-based electrolytes have higher ionic conductivities, and are cost-effective and nonflammable, their high self-discharge rate with organic/carbon-based electrodes impedes their commercialization. It is found out that highly concentrated polymer electrolytes on the concept of "water-in-salt electrolyte" lead to extremely low leakage current within the electrochemical stability window (ESW) of water, thus solving the issue of self-discharge in organic/carbon-based ESDs. Herein, potassium polyacrylate (PAAK) is prepared as "water-in-polymer salt electrolyte" (WIPSE) and tested for one of most abundant wood-based biopolymer lignin and polyimide as positive and negative electrodes, respectively, in both half-cell and full-cell. The device shows an open-circuit voltage drops <0.45V in 100h setting a record for organic batteries using aqueous electrolyte. The high ionic conductivity (40-120mScm(-1)) nonflammability of PAAK with high ESW (3.1V) opens a new direction for truly safe, sustainable, and high power (6.8kWkg(-1)) organic ESD manufactured by printing technologies.
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| 6. |
- Mallhi, Tauqeer Hussain, et al.
(författare)
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Atypical Complications during the Course of COVID-19 : A Comprehensive Review
- 2024
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Ingår i: Medicina. - : MDPI. - 1010-660X .- 1648-9144. ; 60:1
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Forskningsöversikt (refereegranskat)abstract
- COVID-19 is primarily a respiratory disease, but numerous studies have indicated the involvement of various organ systems during the course of illness. We conducted a comprehensive review of atypical complications of COVID-19 with their incidence range (IR) and their impact on hospitalization and mortality rates. We identified 97 studies, including 55 research articles and 42 case studies. We reviewed four major body organ systems for various types of atypical complications: (i) Gastro-intestinal (GI) and hepatobiliary system, e.g., bowel ischemia/infarction (IR: 1.49-83.87%), GI bleeding/hemorrhage (IR: 0.47-10.6%), hepatic ischemia (IR: 1.0-7.4%); (ii) Neurological system, e.g., acute ischemic stroke/cerebral venous sinus thrombosis/cerebral hemorrhage (IR: 0.5-90.9%), anosmia (IR: 4.9-79.6%), dysgeusia (IR: 2.8-83.38%), encephalopathy/encephalitis with or without fever and hypoxia (IR: 0.19-35.2%); (iii) Renal system, e.g., acute kidney injury (AKI)/acute renal failure (IR: 0.5-68.8%); (iv) Cardiovascular system, e.g., acute cardiac injury/non-coronary myocardial injury (IR: 7.2-55.56%), arrhythmia/ventricular tachycardia/ventricular fibrillation (IR: 5.9-16.7%), and coagulopathy/venous thromboembolism (IR: 19-34.4%). This review encourages and informs healthcare practitioners to keenly monitor COVID-19 survivors for these atypical complications in all major organ systems and not only treat the respiratory symptoms of patients. Post-COVID effects should be monitored, and follow-up of patients should be performed on a regular basis to check for long-term complications.
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| 7. |
- Ahmad, Naveed, et al.
(författare)
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The nexus of csr and co-creation : A roadmap towards consumer loyalty
- 2021
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Ingår i: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Corporate Social Responsibility (CSR) is regarded as an effort to be undertaken by the businesses to contribute towards society at large positively. The idea behind the concept of CSR is that businesses are required to pursue the notion of pro-social objectives along with economic objectives. Research has long established that corporate social responsibility, along with its philanthropic nature, can also produce extraordinary marketing results for businesses. The relationship between CSR and consumer loyalty is well acknowledged in extant literature. Likewise, involving consumers through co-creation in the product/service development process may provide an exciting experience to consumers, which is likely to influence their loyalty. With these arguments, the present research investigates the impact of CSR on consumer loyalty with the mediating role of co-creation in the banking sector of an emerging economy such as Pakistan. Structural equation modeling (SEM) is used for data analysis in the present study. The results validate that CSR improves consumer loyalty, and co-creation partially mediates this relationship. The results of the current survey will help banking institutions to identify how they can develop core strategic considerations based on CSR and co-creation.
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| 8. |
- Ail, Ujwala, et al.
(författare)
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Effect of Sulfonation Level on Lignin/Carbon Composite Electrodes for Large-Scale Organic Batteries
- 2020
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Ingår i: ACS Sustainable Chemistry and Engineering. - : AMER CHEMICAL SOC. - 2168-0485. ; 8:49, s. 17933-17944
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Tidskriftsartikel (refereegranskat)abstract
- The key figure-of-merit for materials in stationary energy storage applications, such as large-scale energy storage for buildings and grids, is the cost per kilo per electrochemical cycle, rather than the energy density. In this regard, forest-based biopolymers such as lignin, are attractive, as they are abundant on Earth. Here, we explored lignin as an electroactive battery material, able to store two electrons per hydroquinone aromatic ring, with the targeted operation in aqueous electrolytes. The impact of the sulfonation level of lignin on the performance of its composite electrode with carbon was investigated by considering three lignin derivatives: lignosulfonate (LS), partially desulfonated lignosulfonate (DSLS), and fully desulfonated lignin (KL, lignin produced by the kraft process). Partial desulfonation helped in better stability of the composite in aqueous media, simultaneously favoring its water processability. In this way, a route to promote ionic conductivity within the lignin/carbon composite electrodes was developed, facilitating the access to the entire bulk of the volumetric electrodes. Electrochemical performance of DSLS/C showed highly dominant Faradaic contribution (66%) towards the total capacity, indicating an efficient mixed ionic-electronic transport within the lignin-carbon phase, displaying a capacity of 38 mAh/g at 0.25 A/g and 69% of capacity retention after 2200 cycles at a rate of 1 A/g.
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| 9. |
- Ail, Ujwala, et al.
(författare)
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Room temperature synthesis of transition metal silicide-conducting polymer micro-composites for thermoelectric applications
- 2017
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 225, s. 55-63
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Tidskriftsartikel (refereegranskat)abstract
- Organic polymer thermoelectrics (TE) as well as transition metal (TM) silicides are two thermoelectric class of materials of interest because they are composed of atomic elements of high abundance; which is a prerequisite for mass implementation of thermoelectric (TE) solutions for solar and waste heat recovery. But both materials have drawbacks when it comes to finding low-cost manufacturing. The metal silicide needs high temperature (>1000 °C) for creating TE legs in a device from solid powder, but it is easy to achieve long TE legs in this case. On the contrary, organic TEs are synthesized at low temperature from solution. However, it is difficult to form long legs or thick films because of their low solubility. In this work, we propose a novel method for the room temperature synthesis of TE composite containing the microparticles of chromium disilicide; CrSi2 (inorganic filler) in an organic matrix of nanofibrillated cellulose- poly(3,4-ethyelenedioxythiophene)-polystyrene sulfonate (NFC-PEDOT:PSS). With this method, it is easy to create long TE legs in a room temperature process. The originality of the approach is the use of conducting polymer aerogel microparticles mixed with CrSi2 microparticles to obtain a composite solid at room temperature under pressure. We foresee that the method can be scaled up to fabricate and pattern TE modules. The composite has an electrical conductivity (σ) of 5.4 ± 0.5 S/cm and the Seebeck coefficient (α) of 88 ± 9 ΌV/K, power factor (α2σ) of 4 ± 1 ΌWm−1K−2 at room temperature. At a temperature difference of 32 °C, the output power/unit area drawn across the load, with the resistance same as the internal resistance of the device is 0.6 ± 0.1 ΌW/cm2.
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| 10. |
- Arshad, Farzana, et al.
(författare)
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Compact beam-switchable antenna for mm-wave 5G handheld devices
- 2021
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Ingår i: IET Microwaves, Antennas & Propagation. - : WILEY. - 1751-8725 .- 1751-8733. ; 15:7, s. 778-787
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Tidskriftsartikel (refereegranskat)abstract
- An electronically beam-steerable antenna (BSA) is envisioned. The presented BSA is a possible solution to overthrow the limitations inherent to phased antenna arrays. The design consists of a gap coupling inset feed rectangular patch (driven element) and 3 x 1 passive parasitic patches deployed on both sides of the driven patch. Prototype having 20 x 20 mm dimensions is printed on Rogers(R) RT/duroid(R)5870. Four switches are used to load the reactive impedance on parasitic patches, which in turn, change the phases of surface current on parasitic elements and the driven element. Based on the different ON and OFF configuration of switches in parasitic array elements, the main beam is steered along with different directions. The simulated results show that the design can operate between 26.8 and 30.3 GHz a wide impedance bandwidth |S-11|< -10 dB (12.5%) with a peak gain of 8.9 dBi and wide 3-dB scanning angle that is, -37 degrees to 156 degrees in the azimuth plane. The exhibited performance of BSA with favourable characteristics, such as wideband, adequate gain, wide-angle beam switching, and low profile renders the BSA a good candidate for 5G millimetre wave handheld devices. Moreover, to corroborate the performance, the design is fabricated, and experimental measurements were performed. Congruence is observed between the experimentally measured and computationally simulated results. The simulated results of spherical coverage analysis of BSA with the integration of smartphone form factor are also presented.
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| 11. |
- Basit, Abdul, et al.
(författare)
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Structural Modeling on the Determinants of Effectiveness of SOPs Containing COVID-19 in Mass Gatherings
- 2021
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Ingår i: Frontiers in Psychology. - : Frontiers Media SA. - 1664-1078. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The study is aimed to analyze the determinants of the effectiveness of SOPs in mass gatherings for containing COVID-19. The overall design of the study involves a literature review, data collection by field survey, structural modeling, and analysis. The study is built on the experts' opinion of a focus group (representing people who recently participated in and are responsible for mass gatherings). The study uses the discussion of the literature review to identify the determinants, interpretive structural modeling (ISM) for developing and analyzing a structural model, and Matrice d'Impacts Croises Multiplication Appliquée a un Classement (MICMAC) for corroboration of results of the ISM/classification of determinants. From the literature review, a list of determinants is generated and verified by a panel of experts. The results of the ISM revealed that the determinants “legal environment of the country,” “practicability of SOPs,” “perceived benefit of adapting SOPs,” and “possibilities of avoiding gathering” occupied the top of the model, therefore, they are less critical determinants, whereas “nature of gathering” occupied the bottom of the model, and is thus the most critical determinant. The remaining determinants form the middle of the model, and are therefore moderately severe. The results of MICMAC show that the determinant “perceived benefit of adapting SOPs” is dependent, “nature of gathering” is independent, and all others are linked. The results of MICMAC implicitly substantiate the findings of the ISM. The overall results of the study show that “nature of gathering” is the key determinant. This research does not require a priori theory since it is a theory-building study that uses an inductive approach. It is based on real data and it is useful for local authorities, organizers, participants (attendees/visitors) of mass gatherings, health officials/regulators, researchers, and the community at large. This study has fundamental importance for planning and preparing for such events while ensuring the minimum risk of COVID-19 transmission.
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| 12. |
- Bubnova, Olga, et al.
(författare)
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Advantageous thermoelectric properties of a semimetallic polymer
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Thermoelectric generation potentially holds a solution for waste heat recovery issues provided that the availability of inexpensive, biodegradable and highly efficient thermoelectric materials is insured in the near future. Plastic thermoelectrics could successfully comply with the said requirements if the thermoelectric efficiency (ZT) of conducting polymers was higher. However, given the novelty of the subject, at present there are no clear guidelines for ZT optimization in this class of materials. The most important piece of information that is currently missing is the description of a specific electronic makeup that conducting polymers must possess in order to enable good thermoelectric performance. In the present study the thermoelectric properties of poly(3,4-ethylenedioxythiophene) derivatives with two types of counterions, i.e. poly(styrenesulfonate) (PSS) and tosylate (Tos) are evaluated. A striking variation in their thermoelectric performance is attributed to structural and morphological differences between two polymers that manifest itself in dissimilar charge transport mechanism. The superior properties of PEDOT-Tos presumably originate from a high degree of crystallinity and structural order that predetermines the tendency for bipolaron band formation. Unlike polaronic PEDOT-PSS with slowly varying density of localized states (DOS) near the Fermi level (EF), the DOS in PEDOT-Tos is characterized by higher asymmetry and higher charge carrier density at EF (similar to semimetals), which allows for higher thermopower and electrical conductivity. Therefore, we conclude that the polymers with semimetallic electronic makeup are expected to exhibit promising thermoelectric properties with bigger variation in thermopower upon doping.
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| 13. |
- Bubnova, Olga, et al.
(författare)
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Corrigendum: Semi-metallic polymers
- 2014
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-1122 .- 1476-4660. ; 13, s. 662-662
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Tidskriftsartikel (refereegranskat)
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| 14. |
- Bubnova, Olga, et al.
(författare)
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Optimization of the thermoelectric figure of merit in the conducting polymer poly(3,4-ethylenedioxythiophene)
- 2011
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Ingår i: NATURE MATERIALS. - : Nature Publishing Group. - 1476-1122 .- 1476-4660. ; 10:6, s. 429-433
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Tidskriftsartikel (refereegranskat)abstract
- Thermoelectric generators (TEGs) transform a heat flow into electricity. Thermoelectric materials are being investigated for electricity production from waste heat (co-generation) and natural heat sources. For temperatures below 200 degrees C, the best commercially available inorganic semiconductors are bismuth telluride (Bi2Te3)-based alloys, which possess a figure of merit ZT close to one(1). Most of the recently discovered thermoelectric materials with ZT andgt; 2 exhibit one common property, namely their low lattice thermal conductivities(2,3). Nevertheless, a high ZT value is not enough to create a viable technology platform for energy harvesting. To generate electricity from large volumes of warm fluids, heat exchangers must be functionalized with TEGs. This requires thermoelectric materials that are readily synthesized, air stable, environmentally friendly and solution processable to create patterns on large areas. Here we show that conducting polymers might be capable of meeting these demands. The accurate control of the oxidation level in poly(3,4-ethylenedioxythiophene) (PEDOT) combined with its low intrinsic thermal conductivity (lambda = D 0.37W m(-1) K-1) yields a ZT = 0.25 at room temperature that approaches the values required for efficient devices.
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| 15. |
- Bubnova, Olga, et al.
(författare)
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Semi-metallic polymers
- 2014
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Ingår i: Nature Materials. - : Nature Publishing Group. - 1476-1122 .- 1476-4660. ; 13:2, s. 190-194
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Tidskriftsartikel (refereegranskat)abstract
- Polymers are lightweight, flexible, solution-processable materials that are promising for low-cost printed electronics as well as for mass-produced and large-area applications. Previous studies demonstrated that they can possess insulating, semiconducting or metallic properties; here we report that polymers can also be semi-metallic. Semi-metals, exemplified by bismuth, graphite and telluride alloys, have no energy bandgap and a very low density of states at the Fermi level. Furthermore, they typically have a higher Seebeck coefficient and lower thermal conductivities compared with metals, thus being suitable for thermoelectric applications. We measure the thermoelectric properties of various poly( 3,4-ethylenedioxythiophene) samples, and observe a marked increase in the Seebeck coefficient when the electrical conductivity is enhanced through molecular organization. This initiates the transition from a Fermi glass to a semi-metal. The high Seebeck value, the metallic conductivity at room temperature and the absence of unpaired electron spins makes polymer semi-metals attractive for thermoelectrics and spintronics.
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| 16. |
- Engström, Gunnar, et al.
(författare)
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Marital Dissolution Is Followed by an Increased Incidence of Stroke.
- 2004
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Ingår i: Cerebrovascular Diseases. - : S. Karger AG. - 1421-9786 .- 1015-9770. ; 18:4, s. 318-324
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> Many studies have reported lower mortality in married people. The relation between marital status and incidence of haemorrhagic and ischaemic stroke is unclear. It is largely unknown whether the risk of stroke is increased the first years after divorce or death of spouse. <i>Methods:</i> Incidence of first-ever stroke (n = 6,184) was followed over 10 years in a cohort consisting of all 40- to 89-year-old inhabitants (n = 118,134) in the city of Malmö, Sweden. Marital dissolution (i.e. divorce or death of spouse) prior to the date of stroke was compared in a nested case-control design (3,134 initially married stroke cases, 9,402 initially married controls). <i>Results:</i> As compared to the married groups, the incidence of stroke was increased in divorced men and women (RR = 1.23, CI: 1.10–1.39 and RR = 1.26, CI: 1.12–1.41, respectively) and widowed men and women (RR = 1.13, CI: 0.99–1.28 and RR = 1.13, CI: 1.02–1.24, respectively) after adjustments for age, country of birth and socioeconomic indicators. The risk of stroke was not increased in never married men. Marital dissolution was followed by increased risk of stroke, which was significant for men (adjusted odds ratio: 1.23, CI: 1.03–1.5) and borderline significant for women below 65 years of age (odds ratio: 1.45, CI: 0.99–2.14). <i>Conclusion:</i> The incidence of stroke is increased in divorced and widowed individuals. Never married men do not have an increased incidence. The risk of stroke is elevated during the first years after divorce or death of spouse.
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| 17. |
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| 18. |
- Ghorbani Shiraz, Hamid, 1989-, et al.
(författare)
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3R-TaS2 as an Intercalation-Dependent Electrified Interface for Hydrogen Reduction and Oxidation Reactions
- 2022
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 126:40, s. 17056-17065
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen technology, as a future breakthrough for the energy industry, has been defined as an environmentally friendly, renewable, and high-power energy carrier. The green production of hydrogen, which mainly relies on electrocatalysts, is limited by the high cost and/ or the performance of the catalytic system. Recently, studies have been conducted in search of bifunctional electrocatalysts accelerating both the hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR). Herein, we report the investigation of the high efficiency bifunctional electrocatalyst TaS2 for both the HER and the HOR along with the asymmetric effect of inhibition by organic intercalation. The linear organic agent, to boost the electron donor property and to ease the process of intercalation, provides a higher interlayer gap in the tandem structure of utilized nanosheets. XRD and XPS data reveal an increase in the interlayer distance of 22%. The HER and the HOR were characterized in a Pt group metal-free electrochemical system. The pristine sample shows a low overpotential of -0.016 Vat the onset. The intercalated sample demonstrates a large shift in its performance for the HER. It is revealed that the intercalation is a potential key strategy for tuning the performance of this family of catalysts. The inhibition of the HER by intercalation is considered as the increase in the operational window of a water-based electrolyte on a negative electrode, which is relevant to technologies of electrochemical energy storage.
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| 19. |
- Ghorbani Shiraz, Hamid, et al.
(författare)
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Effect of Oxygen Poisoning on the Bidirectional Hydrogen Electrocatalysis in TaS2 Nanosheets
- 2023
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 127:12, s. 5825-5832
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable production of hydrogen gas, a green energy carrier of high density, is possible only by electrolysis of water based on the hydrogen evolution reaction (HER). Here, we report the effect of oxygen poisoning on the efficiency of hydrogen production and the consumption by the HER and the hydrogen oxidation reaction (HOR), respectively, on the interface of platinum group metal-free electrocatalyst TaS2 in pristine form and intercalated by the organic Lewis base hexylamine. The state of the surface probed by photoelectron spectroscopy was significantly altered by both Lewis base doping and oxygen poisoning. This alteration dramatically affects the hydrogen production efficiency in the HER, while the back process by the HOR was less sensitive to the changes in the surface states of the electrocatalysts. The oxygenated and intercalated electrocatalyst shows more than 2 x 105 times lower exchange current density of the HER compared to pristine oxygenated materials.
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| 20. |
- Han, Shaobo, et al.
(författare)
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Thermoelectric Polymer Aerogels for Pressure-Temperature Sensing Applications
- 2017
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Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 27:44
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of the society is characterized by an increasing flow of information from things to the internet. Sensors have become the cornerstone of the internet-of-everything as they track various parameters in the society and send them to the cloud for analysis, forecast, or learning. With the many parameters to sense, sensors are becoming complex and difficult to manufacture. To reduce the complexity of manufacturing, one can instead create advanced functional materials that react to multiple stimuli. To this end, conducting polymer aerogels are promising materials as they combine elasticity and sensitivity to pressure and temperature. However, the challenge is to read independently pressure and temperature output signals without cross-talk. Here, a strategy to fully decouple temperature and pressure reading in a dual-parameter sensor based on thermoelectric polymer aerogels is demonstrated. It is found that aerogels made of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) can display properties of semiconductors lying at the transition between insulator and semimetal upon exposure to high boiling point polar solvents, such as dimethylsulfoxide (DMSO). Importantly, because of the temperature-independent charge transport observed for DMSO-treated PEDOT-based aerogel, a decoupled pressure and temperature sensing can be achieved without cross-talk in the dual-parameter sensor devices.
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| 21. |
- Jacob, Stephane, et al.
(författare)
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High-performance flexible thermoelectric modules based on high crystal quality printed TiS2/hexylamine
- 2021
-
Ingår i: Science and Technology of Advanced Materials. - : Taylor & Francis Ltd. - 1468-6996 .- 1878-5514. ; 22:1, s. 907-916
-
Tidskriftsartikel (refereegranskat)abstract
- Printed electronics implies the use of low-cost, scalable, printing technologies to fabricate electronic devices and circuits on flexible substrates, such as paper or plastics. The development of this new electronic is currently expanding because of the emergence of the internet-of-everything. Although lot of attention has been paid to functional inks based on organic semiconductors, another class of inks is based on nanoparticles obtained from exfoliated 2D materials, such as graphene and metal sulfides. The ultimate scientific and technological challenge is to find a strategy where the exfoliated nanoparticle flakes in the inks can, after solvent evaporation, form a solid which displays performances equal to the single crystal of the 2D material. In this context, a printed layer, formed from an ink composed of nano-flakes of TiS2 intercalated with hexylamine, which displays thermoelectric properties superior to organic intercalated TiS2 single crystals, is demonstrated for the first time. The choice of the fraction of exfoliated nano-flakes appears to be a key to the forming of a new self-organized layered material by solvent evaporation. The printed layer is an efficient n-type thermoelectric material which complements the p-type printable organic semiconductors The thermoelectric power factor of the printed TiS2/hexylamine thin films reach record values of 1460 mu W m(-1) K-2 at 430 K, this is considerably higher than the high value of 900 mu W m(-1) K-2 at 300 K reported for a single crystal. A printed thermoelectric generator based on eight legs of TiS2 confirms the high-power factor values by generating a power density of 16.0 W m(-2) at Delta T = 40 K.
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| 22. |
- Jiao, Fei, et al.
(författare)
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Nanofibrillated Cellulose-Based Electrolyte and Electrode for Paper-Based Supercapacitors
- 2018
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Ingår i: ADVANCED SUSTAINABLE SYSTEMS. - : Wiley. - 2366-7486. ; 2:1
-
Tidskriftsartikel (refereegranskat)abstract
- Solar photovoltaic technologies could fully deploy and impact the energy conversion systems in our society if mass-produced energy-storage solutions exist. A supercapacitor can regulate the fluctuations on the electrical grid on short time scales. Their mass-implementation requires the use of abundant materials, biological and organic synthetic materials are attractive because of atomic element abundancy and low-temperature synthetic processes. Nanofibrillated cellulose (NFC) coming from the forest industry is exploited as a three-dimensional template to control the transport of ions in an electrolyte-separator, with nanochannels filled of aqueous electrolyte. The nanochannels are defined by voids in the nanocomposite made of NFC and the proton transporting polymer polystyrene sulfonic acid PSSH. The ionic conductivity of NFC-PSSH composites (0.2 S cm(-1) at 100% relative humidity) exceeds sea water in a material that is solid, feel dry to the finger, but filled of nanodomains of water. A paper-based supercapacitor made of NFC-PSSH electrolyte-separator sandwiched between two paper-based electrodes is demonstrated. Although modest specific capacitance (81.3 F g(-1)), power density (2040 W kg(-1)) and energy density (1016 Wh kg(-1)), this is the first conceptual demonstration of a supercapacitor based on cellulose in each part of the device; which motivates the search for using paper manufacturing as mass-production of energy-storage devices.
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| 23. |
- Jo, Young Jin, et al.
(författare)
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Gelatin Hydrogel-Based Organic Electrochemical Transistors and Their Integrated Logic Circuits
- 2018
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 10:45, s. 39083-39090
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Tidskriftsartikel (refereegranskat)abstract
- We suggest gelatin hydrogel as an electrolyte and demonstrate organic electrochemical transistors (OECTs) based on a sheet of gelatin. We also modulate electrical characteristics of the OECT with respect to pH condition of the gelatin hydrogel from acid to base and analyze its characteristics based on the electrochemical theory. Moreover, we extend the gelatin-based OECT to electrochemical logic circuits, for example, NOT, NOR, and NAND gates.
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| 24. |
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| 25. |
- Khan, Farhad, et al.
(författare)
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Incidence of Stroke and Stroke Subtypes in Malmo, Sweden, 1990-2000. Marked Differences Between Groups Defined by Birth Country.
- 2004
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Ingår i: Stroke: a journal of cerebral circulation. - 1524-4628. ; 35:9, s. 2054-2058
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose-The proportion of immigrants has increased in Sweden markedly during the last decades, as in many other Western countries. Incidence of stroke has increased during this period. However, it is primarily unknown whether incidence of stroke and stroke subtypes in Sweden is related to country of birth. Methods-Incidence of first-ever stroke was followed during 10 years in a cohort consisting of all 40- to 89-year-old inhabitants in the city of Malmo, Sweden (n=118134). Immigrants from 12 different countries were compared with native-born Swedes. Results-Adjusted for age, sex, marital status, and socioeconomic indicators, the incidence of stroke ( all subtypes) was significantly higher among immigrants from former Yugoslavia (relative risk [RR], 1.31; 95% CI, 1.1 to 1.6) and Hungary (RR, 1.33; CI, 1.02 to 1.7). A significantly increased incidence of intracerebral hemorrhage was observed in immigrants from Peoples Republic of China or Vietnam (RR, 4.2; CI, 1.7 to 10.4) and the former Soviet Union ( RR, 2.7; CI, 1.01 to 7.3). Immigrants from Finland had a significantly higher incidence of subarachnoid hemorrhage (RR, 2.8; CI, 1.1 to 6.8). A significantly lower incidence of stroke was observed in the group from Romania (RR, 0.14; CI, 0.04 to 0.6). Immigrants from Denmark, Norway, Germany, Chile, Czechoslovakia, and Poland had approximately the same risk as citizens born in Sweden. Conclusions-In this urban population from Sweden, there are substantial differences in stroke incidence and stroke subtypes between immigrants from different countries. To what extent this could be accounted for by exposure to biological risk factors remains to be explored.
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| 26. |
- Khan, UR, et al.
(författare)
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Country level economic disparities in child injury mortality
- 2015
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Ingår i: Archives of disease in childhood. - : BMJ. - 1468-2044 .- 0003-9888. ; 100100 Suppl 1, s. S29-S33
-
Tidskriftsartikel (refereegranskat)abstract
- Injuries are a neglected cause of child mortality globally and the burden is unequally distributed in resource poor settings. The aim of this study is to explore the share and distribution of child injury mortality across country economic levels and the correlation between country economic level and injuries.MethodsAll-cause and injury mortality rates per 100 000 were extracted for 187 countries for the 1–4 age group and under 5s from the Global Burden of Disease Study 2010. Countries were grouped into four economic levels. Gross domestic product (GDP) per capita was used to determine correlation with injury mortality.ResultsFor all regions and country economic levels, the share of injuries in all-cause mortality was greater when considering the 1–4 age group than under 5s, ranging from 36.6% in Organization for Economic Cooperation and Development countries to 10.6% in Sub-Saharan Africa. Except for Sub-Saharan Africa, there is a graded association between country economic level and 1–4 injury mortality across regions, with all low-income countries having the highest rates. Except for the two regions with the highest overall injury mortality rates, there is a significant negative correlation between GDP and injury mortality in Latin America and the Caribbean, Eastern Europe/Central Asia, Asia East/South-East and Pacific and North Africa/ Middle East.ConclusionsChild injury mortality is unevenly distributed across regions and country economic level to the detriment of poorer countries. A significant negative correlation exists between GDP and injury in all regions, exception for the most resource poor where the burden of injuries is highest.
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| 27. |
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| 28. |
- Khan, Yusra Habib, et al.
(författare)
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Parental Perceptions and Barriers towards Childhood COVID-19 Vaccination in Saudi Arabia : A Cross-Sectional Analysis
- 2022
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Ingår i: Vaccines. - : MDPI. - 2076-393X. ; 10:12
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The vaccination of children against Coronavirus disease (COVID-19) is a prime area of focus around the globe and is considered a pivotal challenge during the ongoing pandemic. This study aimed to assess parents ' intentions to vaccinate their children and the barriers related to pediatric COVID-19 vaccination. Methodology: An online web-based survey was conducted to recruit parents with at least one child under the age of 12 years from Saudi Arabia's Al-Jouf region. The parental intentions to vaccinate children were assessed via six items, while barriers against vaccination were assessed through seven items in validated study instrument. A 5-point Likert scale was used to record the responses of parents regarding both their intentions and barriers. Results: In total, 444 parents (28.41 +/- 7.4 years, 65% females) participated in this study. Almost 90% of parents were vaccinated against COVID-19 but only 42% of parents intended to vaccinate their children. The mean intention score was 2.9 +/- 1.36. More than one-third of study participants had no plan to vaccinate their children against COVID-19. The majority of the respondents agreed to vaccinate their children if vaccination was made compulsory by the government (relative index: 0.76, 73%). Out of seven potential barriers analyzed, concerns over vaccine safety and side effects were ranked highest (RII: 0.754), reported by 290 (65%) participants. In multivariate logistic regression, significant predictors of parental intention to vaccinate children were the increased education level of the parents (secondary education: OR = 3.617, p = 0.010; tertiary education: OR = 2.775, p = 0.042), COVID-19 vaccination status (vaccinated: OR = 7.062, p = 0.003), mother's involvement in decisions regarding the child's healthcare (mother: OR 4.353, p < 0.001; both father and mother: OR 3.195, p < 0.001) and parents' trust in the vaccine's safety (OR = 2.483, p = 0.022). Conclusions: This study underscored the low intention among parents to vaccinate their children against COVID-19. Vaccination intention was found to be associated with education, parents' vaccination status, the mother's involvement in healthcare decisions, and parents' trust in the vaccine's safety. On the other hand, parents' concerns over the safety and efficacy of the COVID-19 vaccine were widely reported as barriers to childhood vaccination. The health authorities should focus on addressing parental concerns about vaccines to improve their COVID-19 vaccination coverage.
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| 29. |
- Khan, Zia Ullah, et al.
(författare)
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Nanofibrillated cellulose aerogels functionalized with conducting polymers for thermoelectric and dual-sensing applications
- 2015
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Large amount of heat is wasted in industries, power generation plants and ordinary household appliances. This waste heat, can be a useful input to a thermoelectric generator (TEG) that can convert it to electricity. Conducting polymers (CPs) have been proved as best suited thermoelectric (TE) materials for lower temperatures, being not toxic, abundant in nature and solution processible. So far, CPs have been characterized as thin films, but it needs the third dimension to realize vertical TEGs which is possible by coating it on low thermal conductivity 3D skeletons. In this work, porous bulk cellulose structures have been used as a supporting material and were coated with CPs in various ways. The blend of cellulose and polymer were also freeze-dried, resulting in conducting and soft composites. Those flexible aerogels were utilized as a dual parameter sensor to sense pressure and temperature, based on the concept of thermoelectricity. It opens another application area of sensing, utilizing the thermoelectric phenomenon beyond the prevailing power generation concept. The sensitivity of such materials can be enhanced to make them useful as electronic skin in healthcare and robotics.
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| 30. |
- Malti, Abdellah, et al.
(författare)
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An Organic Mixed Ion-Electron Conductor for Power Electronics
- 2016
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Ingår i: Advanced Science. - : Wiley-Blackwell. - 2198-3844. ; 3:2
-
Tidskriftsartikel (refereegranskat)abstract
- A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors.
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| 31. |
- Malti, Abdellah, et al.
(författare)
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Enabling organic power electronics with a cellulose nano-scaffold
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Exploiting the nanoscale properties of certain materials enables the creation of new materials with a unique set of properties. Here, we report on an electronic (and ionic) conducting paper based on cellulose nanofibrils (CNF) composited with poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), which may be facilely processed into large three-dimensional geometries, while keeping unprecedented electronic and ionic conductivities of 140 S/cm and 20 mS/cm, respectively. This is achieved by cladding the CNF with PEDOT:PSS, and trapping an ion-transporting phase in the interstices between these nanofibrils. The unique properties of the resulting nanopaper composite have been used to demonstrate (electrochemical) transistors, supercapacitors and conductors resulting in exceptionally high device parameters, such as an associated transconductance, charge storage capacity and current level beyond 1 S, 1 F and 1 A, respectively.
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| 32. |
- Mitraka, Evangelia, et al.
(författare)
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Solution processed liquid metal-conducting polymer hybrid thin films as electrochemical pH-threshold indicators
- 2015
-
Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 3:29, s. 7604-7611
-
Tidskriftsartikel (refereegranskat)abstract
- A global and accurate mapping of the environment could be achieved if sensors and indicators are mass-produced at low cost. Printed electronics using polymeric (semi) conductors offer a platform for such sensor/indicator based circuits. Herein, we present the material concept for an electrochemical pH-threshold indicator based on a printable hybrid electrode which comprises a liquid metal alloy (GaInSn) embedded in a conducting polymer matrix (PEDOT). This hybrid electrode displays a large variation in open circuit potential versus pH in an electrochemical cell, which when connected to the gate of an electrochemical transistor leads to a dramatic change in the drain current in a narrow range of pH.
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| 33. |
- Park, Taehyun, et al.
(författare)
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Ionoelastomer electrolytes for stretchable ionic thermoelectric supercapacitors
- 2023
-
Ingår i: Nano Energy. - : ELSEVIER. - 2211-2855 .- 2211-3282. ; 114
-
Tidskriftsartikel (refereegranskat)abstract
- Ionic thermoelectric supercapacitors (ITESCs) produce orders of magnitude higher voltages than those of con-ventional thermoelectrics (TEs) based on the thermo-diffusion of electrons/holes and are therefore attractive for converting low-grade heat into electricity. The stretchability and stability of the whole ITESC are important for wearable heat harvesting applications. Recent studies on ITESC have focused on stretchable ionic TE electrolytes with a giant Seebeck coefficient, but there are no reports of fully stretchable ITESCs for wearable heat harvesting devices due to the lack of stretchable electrodes and stretchable ionic TE electrolytes with stability. Herein, we present a fully stretchable ITESC composed of stable high-performance ionic thermoelectric elastomer (ITE) electrolyte and stretchable gold nanowire (AuNW) electrodes. The ITE shows excellent air stability (> 60 d) in comparison to hydrogel-based electrolytes that are susceptible to dehydration in ambient conditions. Further-more, the ITE exhibits an apparent thermopower up to 38.9 mV K-1 and ionic conductivity of 3.76 x 10-1 mS cm-1, which both are maintained up to a tensile strain of 250%. Finally, a fully stretchable ITESC with AuNW electrodes is developed which can harvest energy from thermal gradients during deformations.
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| 34. |
- Rudd, Sam, et al.
(författare)
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Charge transport and structure in semimetallic polymers
- 2018
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Ingår i: Journal of Polymer Science Part B. - : WILEY. - 0887-6266 .- 1099-0488. ; 56:1, s. 97-104
-
Tidskriftsartikel (refereegranskat)abstract
- Owing to changes in their chemistry and structure, polymers can be fabricated to demonstrate vastly different electrical conductivities over many orders of magnitude. At the high end of conductivity is the class of conducting polymers, which are ideal candidates for many applications in low-cost electronics. Here, we report the influence of the nature of the doping anion at high doping levels within the semi-metallic conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) on its electronic transport properties. Hall effect measurements on a variety of PEDOT samples show that the choice of doping anion can lead to an order of magnitude enhancement in the charge carrier mobilityamp;gt;3 cm(2)/Vs at conductivities approaching 3000 S/cm under ambient conditions. Grazing Incidence Wide Angle X-ray Scattering, Density Functional Theory calculations, and Molecular Dynamics simulations indicate that the chosen doping anion modifies the way PEDOT chains stack together. This link between structure and specific anion doping at high doping levels has ramifications for the fabrication of conducting polymer-based devices. (c) 2017 The Authors. Journal of Polymer Science Part B: Polymer Physics Published by Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 97-104
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| 35. |
- Tahir, M. N., et al.
(författare)
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Road traffic crashes in Ramadan: An observational study [Accidents de la circulation pendant le ramadan: Une étude d'observation]
- 2013
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Ingår i: Eastern Mediterranean Health Journal. - 1020-3397. ; 19:Suppl. 3, s. S147-S151
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate trends in road traffic crashes (RTCs) managed by an emergency service, Rescue 1122, in 2011 in Punjab, Pakistan. RTC data were collected from 35 districts of Punjab and reviewed retrospectively. Data analysis revealed that the service responded to 12 969 RTC emergencies during August 2011 (Ramadan), compared with an average of 11 573 RTCs per month from January to August 2011. The younger age group (11-27 years) was victims in 29% of RTCs; 39% were due to speeding and 43% occurred in peak rush hours (14: 00-18: 00) before iftar (breakfast).Results of the study showed that Rescue 1122 faced more RTCs during Ramadan compared with the preceding months. Road safety is an important public health issue in Pakistan. Although there have been great improvements in roads in the past few years, much work needs to be done to deal with mounting trends in RTCs. Public awareness, political will and stringent law enforcement are key factors.
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| 36. |
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| 37. |
- Ullah Khan, Zia, et al.
(författare)
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Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films
- 2015
-
Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 3, s. 10616-10623
-
Tidskriftsartikel (refereegranskat)abstract
- PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties. Until now, it has been utterly difficult to control all the synthesis parameters and the morphology governing the thermoelectric properties. To improve our understanding of this material, we study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes in the nanoscale morphology due to anion exchange between tosylate and Cl- or OH-. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid-base treatment allows finding the optimum for the power factor in PEDOT-Tos thin films.
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| 38. |
- Ullah Khan, Zia, et al.
(författare)
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Thermoelectric Polymers and their Elastic Aerogels
- 2016
-
Ingår i: Advanced Materials. - : John Wiley & Sons. - 0935-9648 .- 1521-4095.
-
Tidskriftsartikel (refereegranskat)abstract
- Electronically conducting polymers constitute an emerging class of materials for novel electronics, such as printed electronics and flexible electronics. Their properties have been further diversified to introduce elasticity, which has opened new possibility for "stretchable" electronics. Recent discoveries demonstrate that conducting polymers have thermoelectric properties with a low thermal conductivity, as well as tunable Seebeck coefficients - which is achieved by modulating their electrical conductivity via simple redox reactions. Using these thermoelectric properties, all-organic flexible thermoelectric devices, such as temperature sensors, heat flux sensors, and thermoelectric generators, are being developed. In this article we discuss the combination of the two emerging fields: stretchable electronics and polymer thermoelectrics. The combination of elastic and thermoelectric properties seems to be unique for conducting polymers, and difficult to achieve with inorganic thermoelectric materials. We introduce the basic concepts, and state of the art knowledge, about the thermoelectric properties of conducting polymers, and illustrate the use of elastic thermoelectric conducting polymer aerogels that could be employed as temperature and pressure sensors in an electronic-skin.
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| 39. |
- Ullah, Zia, et al.
(författare)
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Mapping institutional interventions to mitigate suicides : A study of causes and prevention
- 2021
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 18:20
-
Tidskriftsartikel (refereegranskat)abstract
- Suicide is an extreme, tragic act and an important subject for social inquiry. It is the rising public health issue prevalent in the Himalayan range of Pakistan. The young and educated population is more prone to suicide instead of using this prime phase of age productively. Unfortunately, the suicide problem remains unaddressed, the causes remain undefined, solutions are not in the works, and in situations when others play a part in driving someone to commit suicide, no one is being held accountable. This study is aimed at uncovering the root causes of suicide and proposing some preventive measures to mitigate the problem. Our team studied three years’ worth of data (2017– 2019) on suicides from the office of Human Rights Commission of Pakistan, Chitral. In addition, we conducted semi-structured interviews of different stakeholders, including family members, neighbors, lawyers, and police personnel. The findings revealed that extended family pressures, the power dynamic between sustainers and dependents, family conflicts, and inheritance cases were the major causes of the domestic violence that preceded suicide attempts. Mental health issues, forced marriages, academic competitions, and flawed litigation processes were also among the leading causes of suicide. Awareness through education and religious sermons, strengthening healthcare organizations, restructuring family systems, establishing police complaint centers, effective prosecution processes, and imparting lifesaving skills have been identified as measures to prevent suicide. This study has theoretical and practical implications, as it adds certain novel variables regarding the causes and solutions of suicide to the existing body of literature and guides public authorities to strengthen institutions to intervene effectively.
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| 40. |
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| 41. |
- Wang, Hui, et al.
(författare)
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Ionic Thermoelectric Figure of Merit for Charging of Supercapacitors
- 2017
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Ingår i: Advanced Electronic Materials. - : WILEY. - 2199-160X. ; 3:4
-
Tidskriftsartikel (refereegranskat)abstract
- Thermoelectric materials enable conversion of heat to electrical energy. The performance of electronic thermoelectric materials is typically evaluated using a figure of merit ZT = sigma alpha 2T/lambda, where sigma is the conductivity, alpha is the so-called Seebeck coefficient, and lambda is the thermal conductivity. However, it has been unclear how to best evaluate the performance of ionic thermoelectric materials, like ionic solids and electrolytes. These systems cannot be directly used in a traditional thermoelectric generator, because they are based on ions that cannot pass the interface between the thermoelectric material and external metal electrodes. Instead, energy can be harvested from the ionic thermoelectric effect by charging a supercapacitor. In this study, the authors investigate the ionic thermoelectric properties at varied relative humidity for the polyelectrolyte polystyrene sulfonate sodium and correlate these properties with the charging efficiency when used in an ionic thermoelectric supercapacitor (ITESC). In analogy with electronic thermoelectric generators, the results show that the charging efficiency of the ITESC can be quantitatively related to the figure of merit ZT(i) = sigma i alpha i2T/lambda. This means that the performance of ionic thermoelectric materials can also be compared and predicted based on the ZT, which will be highly valuable in the design of high-performance ITESCs.
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| 42. |
- Weathers, Annie, et al.
(författare)
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Significant Electronic Thermal Transport in the Conducting Polymer Poly(3,4-ethylenedioxythiophene)
- 2015
-
Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 27:12, s. 2101-2106
-
Tidskriftsartikel (refereegranskat)abstract
- Suspended microdevices are employed to measure the in-plane electrical conductivity, thermal conductivity, and Seebeck coefficient of suspended poly(3,4-ethylenedioxythiophene) (PEDOT) thin films. The measured thermal conductivity is higher than previously reported for PEDOT and generally increases with the electrical conductivity. The increase exceeds that predicted by the Wiedemann-Franz law for metals and can be explained by significant electronic thermal transport in PEDOT.
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| 43. |
- Zhao, Dan, et al.
(författare)
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Ionic thermoelectric supercapacitors
- 2016
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Ingår i: Energy & Environmental Science. - : ROYAL SOC CHEMISTRY. - 1754-5692 .- 1754-5706. ; 9:4, s. 1450-1457
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Tidskriftsartikel (refereegranskat)abstract
- Temperature gradients are generated by the sun and a vast array of technologies and can induce molecular concentration gradients in solutions via thermodiffusion (Soret effect). For ions, this leads to a thermovoltage that is determined by the thermal gradient Delta T across the electrolyte, together with the ionic Seebeck coefficient alpha(i). So far, redox-free electrolytes have been poorly explored in thermoelectric applications due to a lack of strategies to harvest the energy from the Soret effect. Here, we report the conversion of heat into stored charge via a remarkably strong ionic Soret effect in a polymeric electrolyte (Seebeck coefficients as high as alpha(i) = 10 mV K-1). The ionic thermoelectric supercapacitor (ITESC) is charged under a temperature gradient. After the temperature gradient is removed, the stored electrical energy can be delivered to an external circuit. This new means to harvest energy is particularly suitable for intermittent heat sources like the sun. We show that the stored electrical energy of the ITESC is proportional to (Delta T alpha(i))(2). The resulting ITESC can convert and store several thousand times more energy compared with a traditional thermoelectric generator connected in series with a supercapacitor.
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| 44. |
- Zhao, Dan, 1986-, et al.
(författare)
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Polymer gels with tunable ionic Seebeck coefficient for ultra-sensitive printed thermopiles
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Measuring temperature and heat flux is important for regulating any physical, chemical, and biological processes. Traditional thermopiles can provide accurate and stable temperature reading but they are based on brittle inorganic materials with low Seebeck coefficient, and are difficult to manufacture over large areas. Recently, polymer electrolytes have been proposed for thermoelectric applications because of their giant ionic Seebeck coefficient, high flexibility and ease of manufacturing. However, the materials reported to date have positive Seebeck coefficients, hampering the design of ultra-sensitive ionic thermopiles. Here we report an “ambipolar” ionic polymer gel with giant negative ionic Seebeck coefficient. The latter can be tuned from negative to positive by adjusting the gel composition. We show that the ion-polymer matrix interaction is crucial to control the sign and magnitude of the ionic Seebeck coefficient. The ambipolar gel can be easily screen printed, enabling large-area device manufacturing at low cost.
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| 45. |
- Zia, Elisabet, et al.
(författare)
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Risk factors for primary intracerebral hemorrhage : a population-based nested case-control study
- 2006
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Ingår i: Cerebrovascular Diseases. - : S. Karger AG. - 1421-9786 .- 1015-9770. ; 21:1-2, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: In this population-based study, risk factors for primary intracerebral hemorrhage (PICH) and PICH subtypes were explored in a nested case-control design.METHOD: Risk factors were determined in 22,444 men and 10,902 women (mean age 47 years) who participated in a health-screening programme between 1974 and 1991. 147 subjects with CT or autopsy-verified first-ever PICH during the follow-up period (mean 14 years) were compared with 1,029 stroke-free controls, matched for age, sex and screening-year.RESULTS: As compared to controls, PICH cases had significantly higher blood pressure (135/91 vs. 127/85 mm Hg), triglycerides (1.7 vs. 1.4 mmol/l), BMI (25.5 vs. 24.8) and shorter stature (1.73 vs. 1.74 m). Diabetes (6.9 vs. 2.8 %) and history of psychiatric morbidity (19.7 vs. 11.0 %) were more common in PICH cases and more of them were living alone (35.4 vs. 25.5%). After adjustment in a backward logistic regression model, high systolic blood pressure, diabetes, high triglycerides, short stature and psychiatric morbidity remained significantly associated with PICH. As compared to the control group, high systolic blood pressure was significantly associated both with nonlobar and lobar PICH. Diabetes and psychiatric morbidity were associated with nonlobar PICH. Smoking doubled the risk for lobar PICH, but was unrelated to nonlobar PICH.CONCLUSION: In this prospective population-based study, hypertension, diabetes, height, triglycerides and psychiatric morbidity were risk factors for PICH. Smoking was a risk factor for lobar PICH only.
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