Usage of Fomblin Y to Improve Water Repellence of Surface Coatings

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. Relative water repelling abilities of different coatings were determined by measuring contact angle of surfaces with water. Coatings with and without POSS and Fomblin were compared. It was shown that the surfaces treated with both POSS and Fomblin were better at repelling water than those with just POSS or Fomblin alone, or neither

Comparative Solubility of POSS Compounds in Fomblin Y

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. However, in order for this to be successful, POSS must be soluble in Fomblin. Temperature dependence of solubility of Fluoro-Hexyl, Fluoro-Octyl, Fluoro-Decyl POSS in Fomblin was tested using Dynamic Light Scattering. The values were compared, and it was shown that Fluoro-Hexyl Poss had a weak solubility-temperature. Both Fluoro-Octyl and Fluoro-Decyl POSS had strong temperature dependences. However, Fluoro-Decyl Poss appeared to stay super saturated after the solution cooled, and failed to recrystallize

Effects of Surface Coatings on Crystalization of Calcium Sulfate

Deposits from hard water can be problematic as they can form scaling on boilers and cooling towers. Scaling can reduce thermal efficiency. Coatings can be used to prevent mineral fouling by changing the surface energy. Some deposits have inverse solubility; such as calcium sulfate. This means that as temperature rises, they become less soluble and can crystallize out of solution. Calcium sulfate is often found in hard water. Crystalization tests were done to determine how coatings such as various POSS (Polyhedral oligomeric silsesquioxane) compounds acted as nucleating surfaces for calcium sulfate. POSS compounds were tested in particular because they have very low surface energy. This would theoretically make nucleation difficult. Solutions of calcium sulfate were placed in microwave vials with different nucleating surfaces. The vials were sealed and heated to 95˚C. After cooling, tests were done to determine the amount of calcium sulfate that had come out of solution

Unitary partitioning and the contextual subspace variational quantum eigensolver

The contextual subspace variational quantum eigensolver (CS-VQE) is a hybrid quantum-classical algorithm that approximates the ground-state energy of a given qubit Hamiltonian. It achieves this by separating the Hamiltonian into contextual and noncontextual parts. The ground-state energy is approximated by classically solving the noncontextual problem, followed by solving the contextual problem using VQE, constrained by the noncontextual solution. In general, computation of the contextual correction needs fewer qubits and measurements compared with solving the full Hamiltonian via traditional VQE. We simulate CS-VQE on different tapered molecular Hamiltonians and apply the unitary partitioning measurement reduction strategy to further reduce the number of measurements required to obtain the contextual correction. Our results indicate that CS-VQE combined with measurement reduction is a promising approach to allow feasible eigenvalue computations on noisy intermediate-scale quantum devices. We also provide a modification to the CS-VQE algorithm; the CS-VQE algorithm previously could cause an exponential increase in Hamiltonian terms but with this modification now at worst will scale quadratically

Police perceptions of problem-oriented policing and evidence-based policing: evidence from England and Wales

The history of policing is littered with reform programmes, which aim to improve effectiveness, efficiency and legitimacy. Problem-oriented policing (POP) and evidence-based policing (EBP) are two popular and enduring reform efforts, both of which have generated significant researcher and practitioner attention. There are important similarities between POP and EBP: both approaches provide a framework intended to improve the outcomes of policing. There are also key differences, however, in terms of their main objectives, standards of evidence and units of analysis. Despite both approaches being widely advocated and implemented, presently little is known about police practitioner understanding of the relationship between POP and EBP, both in principle and in practice. To address this gap, this paper draws on survey (n = 4,141) and interview (n = 86) data collected from 19 police forces in England and Wales in 2019 to explore police practitioners’ views on the relationship between POP and EBP, and the extent to which these two approaches inform contemporary police practices. Our findings indicate that respondents generally viewed the two approaches as complementary and important frameworks for orienting police work. However, respondents also drew attention to how the two approaches are not always connected organisationally nor in the minds of police personnel. In addition, challenges were identified in the application of both approaches in practice. Our results suggest that more needs to be done to maximise the potential of POP and EBP, both separately and synergistically. The article concludes by suggesting some ways in which this might be achieved

An affordable methodology for quantifying waterborne microplastics - an emerging contaminant in inland-waters

The occurrence of microplastics in marine habitats is well documented and of growing concern. The presence of these small (<5 mm) pieces of plastic is less well recorded in inland water systems. In this paper, we determine a cost-efficient and straightforward method for the collection and identification of microplastics in UK inland waters. We found pieces of microplastic from all sample sites ranging from over 1000 L-1 in the River Tame, to 2.4 L-1 in Loch Lomond. The presence of microplastics in all waters tested suggest it should now be classed as an emergent contaminant, with routine monitoring required

A systematic review of school-based sexual health interventions to prevent STI/HIV in sub-Saharan Africa

Background The HIV/AIDS epidemic remains of global significance and there is a need to target (a) the adolescent age-groups in which most new infections occur; and (b) sub-Saharan Africa where the greatest burden of the epidemic lies. A focused systematic review of school-based sexual health interventions in sub-Saharan Africa to prevent HIV/AIDS and Sexually Transmitted Infections (STI) in this age group was therefore conducted. Methods Searches were conducted in Medline, Embase, Cinahl and PsychINFO according to agreed a priori criteria for studies published between 1986 and 2006. Further searches were conducted in UNAIDS and WHO (World Health Organization) websites, and 'Google'. Relevant journals were hand-searched and references cited in identified articles were followed up. Data extraction and quality assessment was carried out on studies selected for full text appraisal, and results were analysed and presented in narrative format. Results Some 1,020 possible titles and abstracts were found, 23 full text articles were critically appraised, and 12 articles (10 studies) reviewed, reflecting the paucity of published studies conducted relative to the magnitude of the HIV epidemic in sub-Saharan Africa. Knowledge and attitude-related outcomes were the most associated with statistically significant change. Behavioural intentions were more difficult to change and actual behaviour change was least likely to occur. Behaviour change in favour of abstinence and condom use appeared to be greatly influenced by pre-intervention sexual history. Conclusion There is a great need in sub-Saharan Africa for well-evaluated and effective school-based sexual health interventions

Synthesis and structural characterization of a mimetic membrane-anchored prion protein

During pathogenesis of transmissible spongiform encephalopathies (TSEs) an abnormal form (PrPSc) of the host encoded prion protein (PrPC) accumulates in insoluble fibrils and plaques. The two forms of PrP appear to have identical covalent structures, but differ in secondary and tertiary structure. Both PrPC and PrPSc have glycosylphospatidylinositol (GPI) anchors through which the protein is tethered to cell membranes. Membrane attachment has been suggested to play a role in the conversion of PrPC to PrPSc, but the majority of in vitro studies of the function, structure, folding and stability of PrP use recombinant protein lacking the GPI anchor. In order to study the effects of membranes on the structure of PrP, we synthesized a GPI anchor mimetic (GPIm), which we have covalently coupled to a genetically engineered cysteine residue at the C-terminus of recombinant PrP. The lipid anchor places the protein at the same distance from the membrane as does the naturally occurring GPI anchor. We demonstrate that PrP coupled to GPIm (PrP-GPIm) inserts into model lipid membranes and that structural information can be obtained from this membrane-anchored PrP. We show that the structure of PrP-GPIm reconstituted in phosphatidylcholine and raft membranes resembles that of PrP, without a GPI anchor, in solution. The results provide experimental evidence in support of previous suggestions that NMR structures of soluble, anchor-free forms of PrP represent the structure of cellular, membrane-anchored PrP. The availability of a lipid-anchored construct of PrP provides a unique model to investigate the effects of different lipid environments on the structure and conversion mechanisms of PrP

Increased ventral striatal volume in college-aged binge drinkers

BACKGROUND Binge drinking is a serious public health issue associated with cognitive, physiological, and anatomical differences from healthy individuals. No studies, however, have reported subcortical grey matter differences in this population. To address this, we compared the grey matter volumes of college-age binge drinkers and healthy controls, focusing on the ventral striatum, hippocampus and amygdala. METHOD T1-weighted images of 19 binge drinkers and 19 healthy volunteers were analyzed using voxel-based morphometry. Structural data were also covaried with Alcohol Use Disorders Identification Test (AUDIT) scores. Cluster-extent threshold and small volume corrections were both used to analyze imaging data. RESULTS Binge drinkers had significantly larger ventral striatal grey matter volumes compared to controls. There were no between group differences in hippocampal or amygdalar volume. Ventral striatal, amygdalar, and hippocampal volumes were also negatively related to AUDIT scores across groups. CONCLUSIONS Our findings stand in contrast to the lower ventral striatal volume previously observed in more severe forms of alcohol use disorders, suggesting that college-age binge drinkers may represent a distinct population from those groups. These findings may instead represent early sequelae, compensatory effects of repeated binge and withdrawal, or an endophenotypic risk factor