2,107 research outputs found
Climate mitigation through Food-Energy-Water (FEW) conservation
Climate change is our biggest challenge to date. Moving toward mitigating or reducing the likelihood of catastrophic climate change is therefore critical. We need to engage all the wedges or strategies we can to reduce global greenhouse gas emissions and achieve this, including increased energy conservation, consumption of low carbon renewable energy sources, and carbon sequestration. Research integrating social, natural, and engineering sciences that includes non-academic organizations is key to reducing emissions across the energy production and consumption supply chain. This presentation describes such research studying greenhouse gas emissions reductions through household scale food-energy-water consumption in the USA and Netherlands.https://digitalcommons.mtu.edu/techtalks/1037/thumbnail.jp
Maximum performance of piezoelectric energy harvesters when coupled to interface circuits
This paper presents a complete optimization of a piezoelectric vibration energy harvesting system, including a piezoelectric transducer, a power conditioning circuit with full semiconductor device models, a battery and passive components. To the authors awareness, this is the first time and all of these elements have been integrated into one optimization. The optimization is done within a framework, which models the combined mechanical and electrical elements of a complete piezoelectric vibration energy harvesting system. To realize the optimization, an optimal electrical damping is achieved using a single-supply pre-biasing circuit with a buck converter to charge the battery. The model is implemented in MATLAB and verified in SPICE. The results of the full system model are used to find the mechanical and electrical system parameters required to maximize the power output. The model, therefore, yields the upper bound of the output power and the system effectiveness of complete piezoelectric energy harvesting systems and, hence, provides both a benchmark for assessing the effectiveness of existing harvesters and a framework to design the optimized harvesters. It is also shown that the increased acceleration does not always result in increased power generation as a larger damping force is required, forcing a geometry change of the harvester to avoid exceeding the piezoelectric breakdown voltage. Similarly, increasing available volume may not result in the increased power generation because of the difficulty of resonating the beam at certain frequencies whilst utilizing the entire volume. A maximum system effectiveness of 48% is shown to be achievable at 100 Hz for a 3.38-cm3 generator
Service users’ experiences with mobile safety alarms in home care: A qualitative study
Aim
To investigate service users of home-based care experiences of using mobile safety alarm and how the alarm affects their ability to cope with everyday life.
Design
A qualitative study with semi-structured interviews.
Methods
The data were collected through semi-structured interviews and analysed according to systematic text condensation. Four men and six women, between 47 and 85 years of age, were included in the study.
Results
Three main themes emerged in the analysis: dimensions of safety, the functionality of the alarm and variation in user guidance. The greatest benefit of having a mobile safety alarm was the feeling of safety. Moreover, the certainty of obtaining contact with the health professionals in any situation was highly valued. However, regarding implementation of the mobile safety alarm, the findings revealed a varying understanding among the service users. Nevertheless, the need for social interaction in their everyday lives is an important factor to recognize
Architecture-independent power bound for vibration energy harvesters
The maximum output power of energy harvesters driven by harmonic vibrations is well known for a range of specific harvester architectures. An architecture-independent bound based on the mechanical input-power also exists and gives a strict limit on achievable power with one mechanical degree of freedom, but is a least upper bound only for lossless devices. We report a new theoretical bound on the output power of vibration energy harvesters that includes parasitic, linear mechanical damping while still being architecture independent. This bound greatly improves the previous bound at moderate force amplitudes and is compared to the performance of established harvester architectures which are shown to agree with it in limiting cases. The bound is a hard limit on achievable power with one mechanical degree of freedom and can not be circumvented by transducer or power-electronic-interface design
What do survivors of child sexual abuse believe will facilitate early disclosure of sexual abuse?
The purpose of this study was to explore what adult survivors of child sexual abuse (CSA) believe will facilitate early disclosure of sexual abuse. We conducted semi-structured interviews with 12 adult survivors of CSA aged 18–57 years, and analyzed the transcripts using reflexive thematic analysis. Our analysis resulted in three main themes: Adults making it possible to tell; Adults daring to consider the unthinkable; and Conveying knowledge of CSA that facilitates understanding. The findings highlighted the importance of adults facilitating disclosure and making it possible for survivors to tell about their experiences, but also the responsibility adults have to dare to consider the possibility of CSA when children struggle. Another important finding was the significance of enhancing the general population's understanding of the complexity of CSA, including why disclosure is difficult, so adults are given the tools needed to understand and know what to do when they suspect CSA. The findings also have important implications for the planning and implementation of interventions to facilitate early disclosure of CSA.publishedVersio
Teaching interdisciplinary sustainability science teamwork skills to graduate students using in-person and web-based interactions
Interdisciplinary sustainability science teamwork skills are essential for addressing the world’s most pressing and complex sustainability problems, which inherently have social, natural, and engineering science dimensions. Further, because sustainability science problems exist at global scales, interdisciplinary science teams will need to consist of international members who communicate and work together effectively. Students trained in international interdisciplinary science skills will be able to hit the ground running when they obtain jobs requiring them to tackle sustainability problems. While many universities now have sustainability science programs, few offer courses that are interdisciplinary and international in scope. In the fall semester of 2013, we piloted a course for graduate students entitled “Principles of Interdisciplinary Sustainability Research” at Michigan Technological University. This course was part of our United States National Science Foundation Partnerships in International Research and Education project on bioenergy development impacts across the Americas. In this case study, we describe the course development and implementation, share critical insights from our experience teaching the course and student learning outcomes, and give recommendations for future similar course
Addressing Climate Impacts in Alaska Native Tribes: Legal Barriers for Community Relocation due to Thawing Permafrost and Coastal Erosion
Rural communities is Alaska—predominantly Alaska Native Tribes—are at the forefront of climate change impacts and climate justice concerns in the United States. According to the 2019 Alaska statewide threat assessment report, 29 communities are currently experiencing significant climate change-related erosion. Further, 38 communities faces significant flooding, and 35 have major problems with thawing permafrost. Some Alaska Native communities have explored community relocation to adapt to these impacts. Because federal law does not recognize gradual environmental impacts like thawing permafrost and coastal erosion as disasters, these communities are ineligible for disaster funding and struggling with how to adapt to the very urgent—albeit less immediate—issues that they face.
This article analyzes the chalenges of Alaska Native Tribes attempting to access federal assistance for community relocation. While some posit that the federal trust responsibility for Tribal Nations might help leverage federal help with community relocation, the status of Alaska Native Claims Settlement Act (ANCSA) extinguished almost all claims of aboriginal title and reservations in Alaska. General access to federal disaster funding and programs may be another avenue for assistance; however, the limited definition of disaster and overly burdensome requirements for federal programs mean that many Alaska Native communities are left to struggle on their own.
In response to these challenges, this article explores possible solutions to help these communities with their relocation efforts. It examines the newly adopted Building Resilient Communities and Infrastructure Program as a potential funding opportunity for community relocation efforts, along with programs focused on climate justice. Finally, the article concludes by proposing the expansion of a state role in helping coordinate federal grant programs on behalf of Alaska Native Tribes and the funding of resilience officers by the federal government at regional Alaska Native organizations to navigate requirements for community relocation grant programs
Health related quality of life after extremely preterm birth: a matched controlled cohort study
<p>Abstract</p> <p>Background</p> <p>The majority of infants born before the last trimester now grow up. However, knowledge on subsequent health related quality of life (HRQoL) is scarce. We therefore aimed to compare HRQoL in children born extremely preterm with control children born at term. Furthermore, we assessed HRQoL in relation to perinatal and neonatal morbidity and to current clinical and sociodemographic characteristics.</p> <p>Method</p> <p><it>The Child Health Questionnaire </it>(CHQ-PF50) and a general questionnaire were applied in a population based cohort of 10 year old children born at gestational age ≤ 28 weeks or with birth weight ≤ 1000 grams in Western Norway in 1991-92 and in term-born controls, individually matched for gender and time of birth. The McNemar test and paired t-tests were used to explore group differences between preterms and matched controls. Paired regression models and analyses of interaction (SPSS mixed linear model) were used to explore potential effects of sociodemographic and clinical characteristics on HRQoL in the two groups.</p> <p>Results</p> <p>All 35 eligible preterm children participated. None had major impairments. Learning and/or attention problems were present in 71% of preterms and 20% of controls (odds ratio (OR): 7.0; 95% confidence interval (CI): 2.2 to 27.6). Insufficient professional support was described by 36% of preterm vs. 3% of control parents (OR: infinite; CI: 2.7 to infinite). Preterms scored lower on eight CHQ-PF50 sub-scales and the two summary scores, boys accounting for most of the deficits in areas of behavior, psychosocial functioning and parental burden. HRQoL was associated with learning and/or attention problems in both preterm and control children, significantly more so in preterms in areas related to health and parental burden. Within the preterm group, HRQoL was mostly unrelated to perinatal and neonatal morbidity.</p> <p>Conclusions</p> <p>HRQoL for children born extremely preterm, and particularly for boys, was described by parents to be inferior to that of children born at term, and sufficiently poor to affect the daily life of the children and their families. Learning and/or attention problems were reported for a majority of preterms, strongly influencing their HRQoL.</p
The psychological burden of skin diseases: a cross-sectional multicenter study among dermatological out-patients in 13 European countries.
The contribution of psychological disorders to the burden of skin disease has been poorly explored, and this is a large-scale study to ascertain the association between depression, anxiety, and suicidal ideation with various dermatological diagnoses. This international multicenter observational cross-sectional study was conducted in 13 European countries. In each dermatology clinic, 250 consecutive adult out-patients were recruited to complete a questionnaire, reporting socio-demographic information, negative life events, and suicidal ideation; depression and anxiety were assessed with the Hospital Anxiety and Depression Scale. A clinical examination was performed. A control group was recruited among hospital employees. There were 4,994 participants--3,635 patients and 1,359 controls. Clinical depression was present in 10.1% patients (controls 4.3%, odds ratio (OR) 2.40 (1.67-3.47)). Clinical anxiety was present in 17.2% (controls 11.1%, OR 2.18 (1.68-2.82)). Suicidal ideation was reported by 12.7% of all patients (controls 8.3%, OR 1.94 (1.33-2.82)). For individual diagnoses, only patients with psoriasis had significant association with suicidal ideation. The association with depression and anxiety was highest for patients with psoriasis, atopic dermatitis, hand eczema, and leg ulcers. These results identify a major additional burden of skin disease and have important clinical implications.Peer reviewedFinal Published versio
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