| 1. |
- Andres, Britta, 1986-, et al.
(författare)
-
Electrode Mass Balancing as an Inexpensive and Simple Method to Increase the Capacitance of Electric Double-Layer Capacitors
- 2016
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:9, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- Symmetric electric double-layer capacitors (EDLCs) have equal masses of the same active material in both electrodes. However, having equal electrode masses may prevent the EDLC to have the largest possible specific capacitance if the sizes of the hydrated anions and cations in the electrolyte differ because the electrodes and the electrolyte may not be completely utilized. Here we demonstrate how this issue can be resolved by mass balancing. If the electrode masses are adjusted according to the size of the ions, one can easily increase an EDLC's specific capacitance. To that end, we performed galvanostatic cycling to measure the capacitances of symmetric EDLCs with different electrode mass ratios using four aqueous electrolytes-Na2SO4, H2SO4, NaOH, and KOH (all with a concentration of 1 M)-and compared these to the theoretical optimal electrode mass ratio that we calculated using the sizes of the hydrated ions. Both the theoretical and experimental values revealed lower-than-1 optimal electrode ratios for all electrolytes except KOH. The largest increase in capacitance was obtained for EDLCs with NaOH as electrolyte. Specifically, we demonstrate an increase of the specific capacitance by 8.6% by adjusting the electrode mass ratio from 1 to 0.86. Our findings demonstrate that electrode mass balancing is a simple and inexpensive method to increase the capacitance of EDLCs. Furthermore, our results imply that one can reduce the amount of unused material in EDLCs and thus decrease their weight, volume and cost.
|
|
| 2. |
- Bhatara, Anjali, et al.
(författare)
-
Second Language Ability and Emotional Prosody Perception
- 2016
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:6
-
Tidskriftsartikel (refereegranskat)abstract
- The present study examines the effect of language experience on vocal emotion perception in a second language. Native speakers of French with varying levels of self-reported English ability were asked to identify emotions from vocal expressions produced by American actors in a forced-choice task, and to rate their pleasantness, power, alertness and intensity on continuous scales. Stimuli included emotionally expressive English speech (emotional prosody) and non-linguistic vocalizations (affect bursts), and a baseline condition with Swiss-French pseudo-speech. Results revealed effects of English ability on the recognition of emotions in English speech but not in non-linguistic vocalizations. Specifically, higher English ability was associated with less accurate identification of positive emotions, but not with the interpretation of negative emotions. Moreover, higher English ability was associated with lower ratings of pleasantness and power, again only for emotional prosody. This suggests that second language skills may sometimes interfere with emotion recognition from speech prosody, particularly for positive emotions.
|
|
| 3. |
- Birko, S., et al.
(författare)
-
Evaluation of nine consensus indices in delphi foresight research and their dependency on delphi survey characteristics : A simulation study and debate on delphi design and interpretation
- 2015
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 10:8
-
Tidskriftsartikel (refereegranskat)abstract
- The extent of consensus (or the lack thereof) among experts in emerging fields of innovation can serve as antecedents of scientific, societal, investor and stakeholder synergy or conflict. Naturally, how we measure consensus is of great importance to science and technology strategic foresight. The Delphi methodology is a widely used anonymous survey technique to evaluate consensus among a panel of experts. Surprisingly, there is little guidance on how indices of consensus can be influenced by parameters of the Delphi survey itself. We simulated a classic three-round Delphi survey building on the concept of clustered consen-sus/dissensus. We evaluated three study characteristics that are pertinent for design of Delphi foresight research: (1) the number of survey questions, (2) the sample size, and (3) the extent to which experts conform to group opinion (the Group Conformity Index) in a Delphi study. Their impacts on the following nine Delphi consensus indices were then examined in 1000 simulations: Clustered Mode, Clustered Pairwise Agreement, Conger’s Kappa, De Moivre index, Extremities Version of the Clustered Pairwise Agreement, Fleiss’ Kappa, Mode, the Interquartile Range and Pairwise Agreement. The dependency of a consensus index on the Delphi survey characteristics was expressed from 0.000 (no dependency) to 1.000 (full dependency). The number of questions (range: 6 to 40) in a survey did not have a notable impact whereby the dependency values remained below 0.030. The variation in sample size (range: 6 to 50) displayed the top three impacts for the Interquartile Range, the Clustered Mode and the Mode (dependency = 0.396, 0.130, 0.116, respectively). The Group Conformity Index, a construct akin to measuring stubbornness/flexibility of experts’ opinions, greatly impacted all nine Delphi consensus indices (dependency = 0.200 to 0.504), except the Extremity CPWA and the Interquartile Range that were impacted only beyond the first decimal point (dependency = 0.087 and 0.083, respectively). Scholars in technology design, foresight research and future(s) studies might consider these new findings in strategic planning of Delphi studies, for example, in rational choice of consensus indices and sample size, or accounting for confounding factors such as experts’ variable degrees of conformity (stubbornness/flexibility) in modifying their opinions. © 2015 Birko et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
|
|
| 4. |
- Biswas, Animesh, 1978-, et al.
(författare)
-
Facility death review of maternal and neonatal deaths in Bangladesh
- 2015
-
Ingår i: PLOS ONE. - San Francisco, USA : Public Library of Science. - 1932-6203. ; 10:11
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives To explore the experiences, acceptance, and effects of conducting facility death review (FDR) of maternal and neonatal deaths and stillbirths at or below the district level in Bangladesh. Methods This was a qualitative study with healthcare providers involved in FDRs. Two districts were studied: Thakurgaon district (a pilot district) and Jamalpur district (randomly selected from three follow-on study districts). Data were collected between January and November 2011. Data were collected from focus group discussions, in-depth interviews, and document review. Hospital administrators, obstetrics and gynecology consultants, and pediatric consultants and nurses employed in the same departments of the respective facilities participated in the study. Content and thematic analyses were performed. Results FDR for maternal and neonatal deaths and stillbirths can be performed in upazila health complexes at sub-district and district hospital levels. Senior staff nurses took responsibility for notifying each death and conducting death reviews with the support of doctors. Doctors reviewed the FDRs to assign causes of death. Review meetings with doctors, nurses, and health managers at the upazila and district levels supported the preparation of remedial action plans based on FDR findings, and interventions were planned accordingly. There were excellent examples of improved quality of care at facilities as a result of FDR. FDR also identified gaps and challenges to overcome in the near future to improve maternal and newborn health. Discussion FDR of maternal and neonatal deaths is feasible in district and upazila health facilities. FDR not only identifies the medical causes of a maternal or neonatal death but also explores remediable gaps and challenges in the facility. FDR creates an enabled environment in the facility to explore medical causes of deaths, including the gaps and challenges that influence mortality. FDRs mobilize health managers at upazila and district levels to forward plan and improve healthcare delivery. © 2015 Biswas et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
|
|
| 5. |
- Blomquist, Nicklas, 1987-, et al.
(författare)
-
Large-Scale Production of Nanographite by Tube-Shear Exfoliation in Water
- 2016
-
Ingår i: PLOS ONE. - : Nicklas Blomquist. - 1932-6203. ; 11:4
-
Tidskriftsartikel (refereegranskat)abstract
- The number of applications based on graphene, few-layer graphene, and nanographite is rapidly increasing. A large-scale process for production of these materials is critically needed to achieve cost-effective commercial products. Here, we present a novel process to mechanically exfoliate industrial quantities of nanographite from graphite in an aqueous environment with low energy consumption and at controlled shear conditions. This process, based on hydrodynamic tube shearing, produced nanometer-thick and micrometer-wide flakes of nanographite with a production rate exceeding 500 gh-1 with an energy consumption about 10 Whg-1. In addition, to facilitate large-area coating, we show that the nanographite can be mixed with nanofibrillated cellulose in the process to form highly conductive, robust and environmentally friendly composites. This composite has a sheet resistance below 1.75 Ω/sq and an electrical resistivity of 1.39×10-4 Ωm and may find use in several applications, from supercapacitors and batteries to printed electronics and solar cells. A batch of 100 liter was processed in less than 4 hours. The design of the process allow scaling to even larger volumes and the low energy consumption indicates a low-cost process.
|
|
| 6. |
- Bänziger, Tanja, et al.
(författare)
-
Path Models of Vocal Emotion Communication
- 2015
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:9
-
Tidskriftsartikel (refereegranskat)abstract
- We propose to use a comprehensive path model of vocal emotion communication, encompassing encoding, transmission, and decoding processes, to empirically model data sets on emotion expression and recognition. The utility of the approach is demonstrated for two data sets from two different cultures and languages, based on corpora of vocal emotion enactment by professional actors and emotion inference by naive listeners. Lens model equations, hierarchical regression, and multivariate path analysis are used to compare the relative contributions of objectively measured acoustic cues in the enacted expressions and subjective voice cues as perceived by listeners to the variance in emotion inference from vocal expressions for four emotion families (fear, anger, happiness, and sadness). While the results confirm the central role of arousal in vocal emotion communication, the utility of applying an extended path modeling framework is demonstrated by the identification of unique combinations of distal cues and proximal percepts carrying information about specific emotion families, independent of arousal. The statistical models generated show that more sophisticated acoustic parameters need to be developed to explain the distal underpinnings of subjective voice quality percepts that account for much of the variance in emotion inference, in particular voice instability and roughness. The general approach advocated here, as well as the specific results, open up new research strategies for work in psychology (specifically emotion and social perception research) and engineering and computer science (specifically research and development in the domain of affective computing, particularly on automatic emotion detection and synthetic emotion expression in avatars).
|
|
| 7. |
- Carrasco-Marginet, Marta, et al.
(författare)
-
Bioelectrical impedance vector analysis (BIVA) for measuring the hydration status in young elite synchronized swimmers
- 2017
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 12:6
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The assessment of body hydration is a complex process, and no measurement is valid for all situations. Bioelectrical impedance vector analysis (BIVA) has emerged as a relatively novel technique for assessing hydration status in sports. We applied BIVA a) to determine hydration changes evoked by an intense synchronized swimming (SS) training session; b) to characterize the sample of young elite swimmers in relation with a nonathletic reference population; and c) to generate its 50%, 75% and 95% percentiles of the bioelectrical variables.METHODS: Forty-nine elite SS female swimmers of two age categories, comen (Co: 13.9 ± 0.9 years, n = 34) and junior (Jr: 16.3 ± 0.6 years, n = 15), performed a long, high intensity training session. Body mass (BM) and bioelectrical variables (R, resistance; Xc, reactance; PA, phase angle; and Z, impedance module) were assessed pre- and post-training. BIVA was used to characterize 1) the distribution pattern of the bioelectrical vector (BIA vector) for both age groups, and 2) pre- to post-training BIA vector migration. Bioelectrical variables were also correlated with BM change values.RESULTS: Most swimmers were mostly located outside the 75% and some beyond the 95% percentile of the bioelectrical tolerance ellipses of the general population. The BIA vector showed statistically significant differences in both Co (T2 = 134.7, p = 0.0001) and Jr (T2 = 126.2, p < 0.001). Both groups were also bioelectrically different (T2 = 17.6, p < 0.001). After the training session, a decrease in BM (p = 0.0001) and an increase in BIA variables (p = 0.01) was observed. BIVA also showed a significant pre-post vector migration both in Co (T2 = 82.1; p < 0.001) and Jr (T2 = 41.8; p < 0.001). No correlations were observed between BM changes and bioelectrical variables.CONCLUSIONS: BIVA showed specific bioelectrical characteristics in young elite SS athletes. Considering the decrease in BM and the migration of the BIA vector, we conclude that the homeostatic hydration status of these young elite female swimmers was affected by the execution of intense training sessions. From a methodological perspective, BIVA appears to be sensitive enough to detect subtle hydration changes, but further research is needed to ensure its validity and reliability. Moreover, these findings highlight the importance of ensuring adequate fluid intake during training in young SS athletes.
|
|
| 8. |
- Eslami, Bahareh, et al.
(författare)
-
Lifetime abuse and somatic symptoms among older women and men in Europe
- 2019
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 14:8
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Research suggests that survivors of interpersonal violence have an increasing experience of bodily symptoms. This study aims to scrutinise the association between lifetime abuse and somatic symptoms among older women and men, considering demographics/socio-economic, social support and health variables. Methods: A sample of 4,467 community-dwelling persons aged 60–84 years (57.3% women) living in seven European countries (Germany, Greece, Italy, Lithuania, Portugal, Spain, Sweden) was recruited for this cross-sectional study. Lifetime abuse (psychological, physical, sexual, financial and injury) was assessed on the basis of the UK study of elder abuse and the Conflict Tactics Scale-2, while somatic symptoms were assessed by the Giessen Complaint List short version. Results: Women reported somatic symptoms more frequently than men. Multiple regression analyses revealed that lifetime exposure to psychological abuse was associated with higher levels of somatic symptoms among both women and men, while experiencing lifetime sexual abuse was associated with somatic symptoms only among older women, after adjusting for other demographic and socio-economic variables. Country of residence, older age, and low socio-economic status were other independent factors contributing to a higher level of somatic symptoms. Conclusions: The positive association between the experience of abuse during lifetime and the reporting of higher levels of somatic symptoms, in particular among older women, seems to suggest that such complaints in later life might also be related to the experience of mistreatment and not only to ageing and related diseases. Violence prevention throughout lifetime could help to prevent somatic symptoms in later life.
|
|
| 9. |
- Fonseka, R. W., et al.
(författare)
-
Impact of adverse childhood experiences on intimate partner violence perpetration among Sri Lankan Men
- 2015
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 10:8
-
Tidskriftsartikel (refereegranskat)abstract
- In Sri Lanka, over one in three women experience intimate partner violence (IPV) victimization in their lifetime, making it a serious public health concern. Adverse childhood experiences (ACEs) such as child abuse and neglect, witnessing domestic violence, parental separation, and bullying are also widespread. Studies in Western settings have shown positive associations between ACEs and IPV perpetration in adulthood, but few have examined this relationship in a non-Western context. In the present study, we examined the association of ACEs with IPV perpetration among Sri Lankan men surveyed for the UN Multi-Country Study on Men and Violence in Asia and the Pacific. We found statistically significant positive associations between the number of ACE categories (ACE score) and emotional, financial, physical, and sexual IPV perpetration among Sri Lankan men. We analyzed the contributions of each ACE category and found that childhood abuse was strongly associated with perpetration of IPV in adulthood, with sexual abuse associated with the greatest increase in odds of perpetration (Adjusted odds ratio 2.36; 95% confidence interval: 1.69, 3.30). Witnessing abuse of one’s mother was associated with the greatest increase in the odds of perpetrating physical IPV (AOR 1.82; 95% CI: 1.29, 2.58), while lack of a male parental figure was not associated with physical IPV perpetration (AOR 0.76; 95% CI: 0.53,1.09). These findings support a social learning theory of IPV perpetration, in which children who are exposed to violence learn to perpetrate IPV in adulthood. They also suggest that in Sri Lanka, being raised in a female-headed household does not increase the risk of IPV perpetration in adulthood compared to being raised in a household with a male parental figure. The relationship between being raised in a female-headed household (the number of which increased dramatically during Sri Lanka’s recent civil war) and perpetration of IPV warrants further study. Interventions that aim to decrease childhood abuse in Sri Lanka could both protect children now and reduce IPV in the future, decreasing violence on multiple fronts. © 2015 Fonseka et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
|
|
| 10. |
- Forsberg, Viviane, 1981-, et al.
(författare)
-
Exfoliated MoS2 in Water without Additives
- 2016
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:4
-
Tidskriftsartikel (refereegranskat)abstract
- Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants andother funtionalization agents. Pure water should be an ideal solvent, however, it is generallybelieved, based on solubility theories that stable dispersions of water could not be achievedand systematic studies are lacking. Here we describe the use of water as a solvent and thestabilization process involved therein. We introduce an exfoliation method of molybdenumdisulfide (MoS2) in pure water at high concentration (i.e., 0.14±0.01 g L−1). This was achieved by thinning the bulk MoS2by mechanical exfoliation between sand papers and dis-persing it by liquid exfoliation through probe sonication in water. We observed thin MoS2nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of thenanosheets were around 200 nm, the same range obtained in organic solvents. Electropho-retic mobility measurements indicated that electrical charges may be responsible for the sta-bilization of the dispersions. A probability decay equation was proposed to compare thestability of these dispersions with the ones reported in the literature. Water can be used as asolvent to disperse nanosheets and although the stability of the dispersions may not be ashigh as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable.
|
|
