67 research outputs found

    Elektrolyty typu voda v soli pro duální iontové baterie

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    Key Words: water-in-salt electrolytes; dual-ion batteries; anion-intercalation; chaotropic anion Abstract Aqueous electrolytes offer high intrinsic safety, high ionic conductivity, and low costs, which makes them very attractive for electrochemical energy storage systems (EESS). Nevertheless, their biggest bottleneck is the narrow electrochemical stability window (ESW) of water of 1.23V, beyond which water undergoes hydrogen and oxygen evolution reactions. This restricts the choice of electrode materials within the H2 and O2 evolution potentials and limits the achievable energy and power densities of aqueous-based EESS. For instance, aqueous multivalent aluminum- and zinc-based batteries promise high energy density due to the multivalent redox chemistry of metal- ions (Al3+ , Zn2+ ), but they exhibit much lower energy density owing to the small ESW of the aqueous electrolytes, which does not allow using high-voltage cathodes. In this thesis, the issue of the narrow ESW for these multivalent batteries has been addressed by using the concept of "water-in-salt" electrolytes (WiSE). This concept is based on using high concentrations of salts in aqueous electrolytes, which results in strong modifications of the water structure and widening of the ESW by restricting the free water content in WiSE. More...(Czech) Vodné elektrolyty nabízejí vysokou bezpečnost, vysokou iontovou vodivost a nízké náklady, což je činí velmi atraktivními pro systémy skladování elektrochemické energie. Nicméně jejich největším úskalím je velmi úzké potenciálové okno elektrochemické stability vody (1,23 V), mimo které se voda začne rozkládat na vodík a kyslík. To omezuje výběr vhodných elektrodových materiálů a dosažitelnou energetickou hustotu v těchto vodných systémech. Například vodné multivalentní baterie na bázi hliníku a zinku, které slibují vysokou hustotu energie díky multivalentní redoxním reakcím kovových iontů (Al3+ , Zn2+ ), v reálu vykazují mnohem nižší hustotu energie kvůli malému potenciálovému oknu vodných elektrolytů, které neumožňuje použití vysokonapěťových katod. V této dizertační práci jsou studovány vodné elektrolyty založené na konceptu voda v soli (WiSE) a řešena problematika nízkého elektrochemického potenciálového okna ve vodných elektrolytech v multivalentních kovových bateriích. V práci je ukázáno, že ve WiSE elektrolytech dochází k výrazné modifikaci struktury vody a rozšíření potenciálového okna v důsledku minimalizace obsahu volných molekul v těchto roztocích. Jsou studovány též vlastnosti aniontů při expanzi potenciálového okna s ohledem jejich umístění v Hofmeisterově řadě, která třídí...Katedra fyzikální a makromol. chemieDepartment of Physical and Macromolecular ChemistryFaculty of SciencePřírodovědecká fakult

    Analyzing Global and Local Media Representations of Malala Yousafzai

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    During the War on Terror, when high rates of violence were occurring and schools were being forcefully torn down in Swat Valley of Pakistan, Malala Yousafzai fought for girls’ education rights. At just 17 years old, Malala Yousafzai has inspired people around the world with her passion and determination to make sure girls everywhere can get an education. When the Taliban tried to silence her, Malala answered their brutality with strength and resolve. Soon in the international media, she was acclaimed as a brave hero and later honored with a Nobel Prize. She received a mixed response for her efforts in Pakistan. While some praised her, others thought her as an opportunist or believed that there was a Western conspiracy behind her promotion on an international level. This article explores the disparities in media representation of Malala Yousafzai on global and local levels. Employing ethnographic research methods, we bring to light the perceptions of people from her hometown and juxtapose it with those of international media outlets. The article will help understand the complex controversies surrounding Yousafzai’s struggle and legacy

    Comparative Study of the Attitudes of Rural and Urban Punjabi Society towards Caste Stereotypes in Punjabi Language

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    This study compares attitudes of rural/urban population of Punjab (Pakistan) towards caste-stereotypes in Punjabi language. The data were collected from District Vehari of southern Punjab including its two adjacent sub-divisions Burewla and Mailsi through questionnaire and interviews; and analyzed using SPSS. The results reveal that there is considerable difference among the attitudes of urban/rural population regarding beliefs and foundations of the caste-stereotypes and their impacts on social life. Besides, people living in rural areas are more prone to using caste-stereotypes than their urban counterparts. Similar trend is observed in the effect of caste-stereotypes on their social relations. DOI: 10.5901/mjss.2015.v6n1s1p62

    Cathode materials for rechargeable aluminum batteries : current status and progress

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    This work was financially supported by the National Natural Science Foundation of China (No. 21477046, 21277060 and 51361130151), Key Technology R&D Program of Shandong Province (No. 2016ZDJS11A03), Science Development Project of Shandong Province (No. 2014GGX104004) and Natural Science Foundation of Shandong Province (No. ZR2015EM044).Peer reviewedPostprin

    Perceptions of health professionals regarding minimally invasive tissue sampling (MITS) to identify the cause of death in stillbirths and neonates: Results from a qualitative study

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    Background: Pakistan is considered to be one of the riskiest places in the world for childbirth as measured by its high stillbirth and neonatal mortality rates. Complete diagnostic autopsy remains the gold standard to determine the cause of death (CoD); however, it is not routinely implemented due to religious objections, sociocultural beliefs, limited resources and low demand from physicians and families. Recently, minimally invasive tissue sampling (MITS) using needle biopsies of multiple tissues to obtain tissue for histological examination and organism identification with PCR has been developed and promoted to determine CoD in low-resource areas. To ensure successful implementation of MITS, it is important to understand health professionals\u27 attitudes and perceptions related to MITS.Methods: A qualitative study was conducted at the National Institute of Child Health (NICH), Karachi, Pakistan. Focus group discussions (FGDs) and Key-informant interviews (KIIs) were conducted with health professionals including doctors, nurses, trainees, clinicians, bioethics experts and public health experts to explore their perceptions and views on acceptability of MITS. Data were analyzed using NVivo 10 software.Results: A total of 12 interviews (FGDs = 4; KIIs = 8) were conducted. Four overarching themes were identified: (I) acceptability of MITS; (II) perceived benefits of the MITS procedure; (III) factors facilitating the implementation of MITS; and (IV) health system requirements for implementing the MITS procedure. Generally, MITS was considered as a positive development for the health system. Diagnostic accuracy and identification of less common causes of death were highlighted as two main benefits of the MITS procedure. The study highlighted a number of facilitators for the acceptability of MITS including effective counseling, building trust with parents, fast procedure time, and approaching families within a few hours of death. In addition, lack of skilled staff, poorly equipped healthcare facilities and the potential high cost to conduct MITS were identified as challenges for the implementation of MITS.Conclusions: This formative research provided a unique opportunity to explore health professionals\u27 views and attitudes towards the MITS procedure. Such insights are crucial to ensure successful implementation and integration of a new technique into the existing health system. The research identified the factors influencing the acceptability of MITS among health professionals in Pakistan. The study also informed factors that could help facilitate the implementation of the MITS procedures in the context of Pakistan and similar settings

    Acaricidal and insecticidal effects of essential oils against ectoparasites of veterinary importance

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    Ectoparasitism in animals has become an issue of great concern that needs to be resolved to prevent huge economic losses occurring to livestock industry all over the world. Synthetic adrugs have been playing a major role in controlling ectoparasites, but their frequent and irrational use has resulted in drug resistance to routinely used chemicals and their residual effects on food and environment. Therefore, this approach of using chemical acaricides and insecticides is losing its popularity and effectiveness in controlling ectoparasites. So, the development of alternative approaches in ectoparasite management is currently required. Among alternative protocols, plants and their essential oils have played remarkable role in controlling different ectoparasites (ticks, flies, mites, lice) of veterinary importance. Essential oils have been proved to be cheaper, more effective and safer therapeautic agents against different ectoparasites of livestock importance

    Perceptions of parents and religious leaders regarding minimal invasive tissue sampling to identify the cause of death in stillbirths and neonates: Results from a qualitative study

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    Background: Recently, the minimal invasive tissue sampling (MITS) procedure has been developed to support determination of the cause of death as an alternate to conventional autopsy, especially in countries where complete diagnostic autopsy is not routine. To assess the feasibility of implementation of the MITS procedure for a study to determine cause of death in premature births and stillbirths in south Asia, we explored the views and perceptions of parents and religious leaders on the acceptability of MITS.Methods: A qualitative study was conducted at the National Institute of Child Health (NICH) hospital of Karachi, Pakistan. Focus group discussions (FGDs) were conducted with parents of newborns who visited well-baby clinics of the NICH hospital for post-natal check-ups. Key-informant interviews (KIIs) were conducted with religious leaders. Data were analyzed using NVivo 10 software.Results: A total of 13 interviews (FGDs = 8; KIIs = 5) were conducted. Three overarching themes were identified: (I) acceptability of MITS; (II) concerns affecting the implementation of MITS; and (III) religious and cultural perspectives. Participants\u27 acceptance of MITS was based on personal, religious, cultural and social beliefs. Parents widely recognized the need for this procedure in cases where the couple had experienced multiple stillbirths, neonatal deaths and miscarriages. Counseling of parents was considered vital to address emotional concerns of the parents and the family. Religious leaders indicated acceptability of the MITS procedure from a religious perspective and advised that respect for the deceased and consent of the guardians is mandatory when performing MITS.Conclusions: This qualitative study provided a unique opportunity to understand the views of parents and religious leaders towards the use of MITS. Generally, MITS appears to be an acceptable method for identifying the cause of death in neonates and stillbirths, provided that the deceased is respected and buried as soon as possible without any delays and parents are counseled appropriately. Findings from this research are essential in approaching families for consent for MITS

    Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: A systematic analysis for the Global Burden of Disease Study 2017

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. Methods: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Findings: Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs 1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]). Interpretation: Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury
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