Model-Based Design of an Optimal Lqg Regulator for a Piezoelectric Actuated Smart Structure Using a High-Precision Laser Interferometry Measurement System

Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes. The analytical model of the smart structure is derived using the extended Hamilton Principle and Euler-Bernoulli beam theory, and the equations of motion for the system are constructed using the assumed-modes method. The analytical model is organized in state-space form, in which the effects of a low-pass filter and sampling of the digital control system are also accounted for. The analytical model is subsequently validated against a finite-element model in Abaqus, a lumped parameter model in Simscape Multibody, and experimental modal analysis using the physical system. A discrete-time proportional-derivative (PD) controller is designed in a heuristic fashion to serve as a baseline performance criterion for the LQG regulator. The Kalman Filter observer and Linear Quadratic Regulator (LQR) components of the LQG regulator are also derived from the state-space model. It is found that the behavior of the analytical model closely matches that of the physical system, and the performance of the LQG regulator exceeds that of the PD controller. The LQG regulator demonstrated quality estimation of the state variables of the system and further constitutes an exceptional closed-loop control system for active vibration control and disturbance rejection of the smart structure

Free range chicken farms - odour emissions and nutrient management

This report focuses on odour emissions and nutrient management from free range meat chicken farms. Specifically – odour emissions from the sheds and free range area as well as potential nitrogen and phosphorus loss from the range areas in the soil and in runoff. There is currently a lack of information relating to free range meat chicken farms when it comes to odour emissions and nutrient loss. Improved understanding of the emissions from free range farms will support the continued growth of the free range sector in Australia

Understanding health behaviour in pregnancy and infant feeding intentions in low-income women from the UK through qualitative visual methods and application to the COM-B (Capability, Opportunity, Motivation-Behaviour) model

Background: Health behaviours during pregnancy and the early years of life have been proven to affect long term health, resulting in investment in interventions. However, interventions often have low levels of completion and limited effectiveness. Consequently, it is increasingly important for interventions to be based on both behaviour change theories and techniques, and the accounts of pregnant women. This study engaged with pregnant women from deprived communities, to understand their subjective experiences of health in pregnancy. Methods: The study adopted a women-centred ethos and recruited a purposive sample of ten pregnant women, who lived in deprived areas and were on low incomes. Participants engaged with three creative techniques of visual data production (timelines, collaging and dyad sandboxing), followed by elicitation interviews. One participant only engaged in the initial activity and interview, resulting in a total of 28 elicitation interviews. This in-depth qualitative approach was designed to enable a nuanced account of the participants’ thoughts, everyday experiences and social relationships. Data were deductively coded for alcohol, smoking and infant feeding and then mapped to the COM-B model (Capability, Opportunity, Motivation – Behaviour). Results: Five participants had experience of smoking during pregnancy, four had consumed alcohol during pregnancy, and all participants, except one who had exclusively formula fed her child, disclosed a range of infant feeding experiences and intentions for their current pregnancies. Considerable variation was identified between the drivers of behaviour around infant feeding and that related to abstinence from tobacco and alcohol during pregnancy. Overall, knowledge and confidence (psychological capability), the role of partners (social opportunity) and support from services to overcome physical challenges (environmental opportunity) were reported to impact on (reflective) motivation, and thus women’s behaviour. The role of the public in creating and reinforcing stigma (social opportunity) was also noted in relation to all three behaviours. Conclusions: When designing new interventions to improve maternal health behaviours it is important to consider the accounts of pregnant women. Acknowledging pregnant women’s subjective experiences and the challenges they face in negotiating acceptable forms of motherhood, can contribute to informed policy and practice, which can engage rather than isolate potential user groups

Smoking during pregnancy, stigma and secrets: Visual methods exploration in the UK

Background: Moral judgements are commonly directed towards mothers through reference to health behaviour in pregnancy, and working-class mothers are particularly subject to this moral gaze. Aim: To gain an in-depth understanding of the health issues affecting 10 low income pregnant women from deprived areas of south Wales, UK. Methods: Participants completed visual activities (timelines, collaging or thought bubbles and dyad sandboxing) prior to each interview. Participants’ visual representations were used in place of a topic guide, to direct the interview. Guided by feminist principles, 28 interviews were completed with 10 women. Data were analysed thematically. Findings: Smoking was discussed at length during interviews, and this paper focuses on this issue alone. Five of the participants had smoked during pregnancy. Negative reactions were directed towards pregnant women who smoked in public, resulting in maternal smoking being undertaken in private. Participants also reported awkward relationships with midwives and other health professionals, including receipt of public health advice in a judgemental tone. Discussion: Smoking during pregnancy is a particularly demonised and stigmatised activity. This stigma is not always related to the level of risk to the foetus, and instead can be seen as a moral judgement about women. We urgently need to move from individualised neo-liberal discourses about the failure of individual smokers, to a more socio-ecological view which avoids victim blaming. Conclusion: Stigma from friends, family, strangers and health professionals may lead to hidden smoking. This is a barrier to women obtaining evidence based stop smoking support

Realising dignity in care home practice: an action research project

Background: More than 400,000 older people reside in over 18,000 care homes in England. A recent social care survey found up to 50% of older people in care homes felt their dignity was undermined. Upholding the dignity of older people in care homes has implications for residents’ experiences and the role of Registered Nurses. Aims and objectives: The study aimed to explore how best to translate the concept of dignity into care home practice, and how to support this translation process by enabling Registered Nurses to provide ethical leadership within the care home setting. Design: Action research with groups of staff (Registered Nurses and non-registered caregivers) and groups of residents and relatives in four care homes in the south of England to contribute to the development of the dignity toolkit. Methods: Action research groups were facilitated by 4 researchers (2 in each care home) to discuss dignity principles and experiences within care homes. These groups reviewed and developed a dignity toolkit over six cycles of activity (once a month for 6 months). The Registered Nurses were individually interviewed before and after the activity. Results: Hard copy and online versions of a dignity toolkit, with tailored versions for participating care homes, were developed. Registered Nurses and caregivers identified positive impact of making time for discussion about dignity-related issues. Registered Nurses identified ongoing opportunities for using their toolkit to support all staff. Conclusions: Nurses and caregivers expressed feelings of empowerment by the process of action research. The collaborative development of a dignity toolkit within each care home has the potential to enable ethical leadership by Registered Nurses that would support and sustain dignity in care homes. Implications for practice: Action research methods empower staff to maintain dignity for older people within the care home setting through the development of practically useful toolkits to support everyday care practice. Providing opportunities for caregivers to be involved in such initiatives may promote their dignity and sense of being valued. The potential of bottom-up collaborative approaches to promote dignity in care therefore requires further research

Estimating hydrodynamic roughness in a wave-dominated environment with a high-resolution acoustic Doppler profiler

Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 110 (2005): C06014, doi:10.1029/2003JC001814.Hydrodynamic roughness is a critical parameter for characterizing bottom drag in boundary layers, and it varies both spatially and temporally due to variation in grain size, bedforms, and saltating sediment. In this paper we investigate temporal variability in hydrodynamic roughness using velocity profiles in the bottom boundary layer measured with a high-resolution acoustic Doppler profiler (PCADP). The data were collected on the ebb-tidal delta off Grays Harbor, Washington, in a mean water depth of 9 m. Significant wave height ranged from 0.5 to 3 m. Bottom roughness has rarely been determined from hydrodynamic measurements under conditions such as these, where energetic waves and medium-to-fine sand produce small bedforms. Friction velocity due to current u *c and apparent bottom roughness z 0a were determined from the PCADP burst mean velocity profiles using the law of the wall. Bottom roughness k B was estimated by applying the Grant-Madsen model for wave-current interaction iteratively until the model u *c converged with values determined from the data. The resulting k B values ranged over 3 orders of magnitude (10−1 to 10−4 m) and varied inversely with wave orbital diameter. This range of k B influences predicted bottom shear stress considerably, suggesting that the use of time-varying bottom roughness could significantly improve the accuracy of sediment transport models. Bedform height was estimated from k B and is consistent with both ripple heights predicted by empirical models and bedforms in sonar images collected during the experiment

Airborne Bacterial and Eukaryotic Community Structure across the United Kingdom Revealed by High-Throughput Sequencing

Primary biological aerosols often include allergenic and pathogenic microorganisms posing potential risks to human health. Moreover, there are airborne plant and animal pathogens that may have ecological and economic impact. In this study, we used high-throughput sequencing techniques (Illumina, MiSeq) targeting the 16S rRNA genes of bacteria and the 18S rRNA genes of eukaryotes, to characterize airborne primary biological aerosols. We used a filtration system on the UK Facility for Airborne Atmospheric Measurements (FAAM) research aircraft to sample a range of primary biological aerosols across southern England overflying surface measurement sites from Chilbolton to Weybourne. We identified 30 to 60 bacterial operational taxonomic units (OTUs) and 108 to 224 eukaryotic OTUs per sample. Moreover, 16S rRNA gene sequencing identified significant numbers of genera that have not been found in atmospheric samples previously or only been described in limited number of atmospheric field studies, which are rather old or published in local journals. This includes the genera Gordonia, Lautropia, and Psychroglaciecola. Some of the bacterial genera found in this study include potential human pathogens, for example, Gordonia, Sphingomonas, Chryseobacterium, Morganella, Fusobacterium, and Streptococcus. 18S rRNA gene sequencing showed Cladosporium to be the major genus in all of the samples, which is a well-known allergen and often found in the atmosphere. There were also genetic signatures of potentially allergenic taxa; for example, Pleosporales, Phoma, and Brassicales. Although there was no significant clustering of bacterial and eukaryotic communities depending on the sampling location, we found meteorological factors explaining significant variations in the community composition. The findings in this study support the application of DNA-based sequencing technologies for atmospheric science studies in combination with complementary spectroscopic and microscopic techniques for improved identification of primary biological aerosols

Airborne Prokaryotic, Fungal and Eukaryotic Communities of an Urban Environment in the UK

Bioaerosols often contain human pathogens and allergens affecting public health. However, relatively little attention has been given to bioaerosols compared with non-biological aerosols. In this study, we aimed to identify bioaerosol compositions in Manchester, UK by applying high throughput sequencing methods and to find potential sources. Samples were collected at Manchester Air Quality Super Site at the Firs Environmental Research Station in November 2019 and in February 2020. Total DNA has been extracted and sequenced targeting the 16S rRNA gene of prokaryotes, ITS region of fungal DNA and 18S rRNA gene of eukaryotes. We found marine environment-associated bacteria and archaea were relatively more abundant in the February 2020 samples compared with the November 2019 samples, consistent with the North West marine origin based on wind back-trajectory analysis. In contrast, an OTU belonging to Methylobacterium, which includes many species resistant to heavy metals, was relatively more abundant in November 2019 when there were higher metal concentrations. Fungal taxa that fruit all year were relatively more abundant in the February 2020 samples while autumn fruiting species generally had higher relative abundance in the November 2019 samples. There were higher relative abundances of land plants and algae in the February 2020 samples based on 18S rRNA gene sequencing. One of the OTUs belonging to the coniferous yew genus Taxus was more abundant in the February 2020 samples agreeing with the usual pollen season of yews in the UK which is from mid-January until late April. The result from this study suggests a potential application of bioaerosol profiling for tracing the source of atmospheric particles