Materials and methods for encapsulation of OPV: A review

Amongst alternative energy sources, photovoltaics hold a considerable promise for it is a plentiful, easily accessible and renewable source of power. Yet, the overall cost of generating electricity using the most advanced silicon based solar cells remains high compared to both traditional and other renewable power generation approaches. Organic thin film photovoltaics are an emerging economically competitive photovoltaic technology that combines manufacturing adaptability, low-cost processing and a lightweight, flexible device end-product. At present, however, commercial use of organic photovoltaics is hindered by low conversion efficiency and poor overall stability of the devices. Encapsulation with high barrier performance materials and structures is one of the key ways to address these issues and improve device lifetime. This paper will briefly outline the current understanding of the major degradation mechanisms, their interrelation and the internal and external factors that initiate these processes. Then, the paper will provide an overview of currently available encapsulant materials, their utility in limiting chemical (water vapor and oxygen penetration) and mechanical degradation within individual layers and device as a whole, and potential drawbacks to their application in organic photovoltaic devices.

Green building incentives: A review

Green building incentives are important to promoting green building. However, it lacks a systematic review of existing knowledge. This paper aims to elicit the common themes in studies of green building incentives through a systematic review. It is found that the common research areas into green building incentives are incentive categorisation, its effectiveness on promoting green building development, criticism of current green incentive implementation and strategies for improving green building incentives. Green building incentives are categorised into external and internal incentives. The external incentive is a forced choice whereby beneficiaries are required to fulfil specified conditions or requirements before benefitting, while the internal incentive allows beneficiaries to be incentivised out of volition because of the appeal of the benefits of green buildings. The external incentives, which are largely provided by the government, are divided into financial and non-financial incentives. It is found that owners are more incentivised by non-financial incentives. In terms of effectiveness, both external and internal incentives are important instruments for promoting green building, although it is not clear which are the more effective. Furthermore, the review uncovered criticisms of external green building incentives, which mainly focus on shortcomings in administering the incentives by the government. The strategies for improving green building incentives were also found, the most important of these being the need for the government to redirect its approach of providing incentives so that owners can be encouraged to pursue green building. The review findings signify the importance of the government in relation to green building incentives. Further research areas that could expand the knowledge of green building incentives are also recommended.

Attrition and success rates of accelerated students in nursing courses: A systematic review

Background There is a comprehensive literature on the academic outcomes (attrition and success) of students in traditional/baccalaureate nursing programs, but much less is known about the academic outcomes of students in accelerated nursing programs. The aim of this systematic review is to report on the attrition and success rates (either internal examination or NCLEX-RN) of accelerated students, compared to traditional students. Methods For the systematic review, the databases (Pubmed, Cinahl and PsychINFO) and Google Scholar were searched using the search terms ‘accelerated’ or ‘accreditation for prior learning’, ‘fast-track’ or ‘top up’ and ‘nursing’ with ‘attrition’ or ‘retention’ or ‘withdrawal’ or ‘success’ from 1994 to January 2016. All relevant articles were included, regardless of quality. Results The findings of 19 studies of attrition rates and/or success rates for accelerated students are reported. For international accelerated students, there were only three studies, which are heterogeneous, and have major limitations. One of three studies has lower attrition rates, and one has shown higher success rates, than traditional students. In contrast, another study has shown high attrition and low success for international accelerated students. For graduate accelerated students, most of the studies are high quality, and showed that they have rates similar or better than traditional students. Thus, five of six studies have shown similar or lower attrition rates. Four of these studies with graduate accelerated students and an additional seven studies of success rates only, have shown similar or better success rates, than traditional students. There are only three studies of non-university graduate accelerated students, and these had weaknesses, but were consistent in reporting higher attrition rates than traditional students. Conclusions The paucity and weakness of information available makes it unclear as to the attrition and/or success of international accelerated students in nursing programs. The good information available suggests that accelerated programs may be working reasonably well for the graduate students. However, the limited information available for non-university graduate students is weak, but consistent, in suggesting they may struggle in accelerated courses. Further studies are needed to determine the attrition and success rates of accelerated students, particularly for international and non-university graduate students.

Ways of Explaining Workplace Bullying: A Review of Enabling, Motivating, and Precipitating Structures and Processes in the Work Environment

This paper summarizes literature explaining workplace bullying and focuses on organisational antecedents of bullying. In order to better understand the logic behind bullying, a model discussing different types of explanations is put forward. Thus, explanations for and factors associated with bullying are classified into three groups, i.e. enabling structures or necessary antecedents (e.g. perceived power imbalances, low perceived costs, and dissatisfaction and frustration), motivating structures or incentives (e.g. internal competition, reward systems, and expected benefits), and precipitating processes or triggering circumstances (e.g. downsizing and restructuring, organisational changes, changes in the composition of the workgroup). The paper concludes that bullying is often an interaction between structures and processes from all three groupings.

Low-temperature internal friction of glass ceramics

Low-temperature internal-friction measurements have been used to study the universal low-energy excitations in glasses before and after crystallization in two glass ceramics, one based on MgO-Al2O3-SiO2 (Corning Code 9606) and one based on Li2O-Al2O3-SiO2 (Corning Code 9623). In the Code 9606 sample, the number density of excitations is greatly reduced, while in the Code 9623 sample, their number density remains practically unaltered in the crystallized state. These measurements confirm the conclusions reached by Cahill et al. (preceding paper), which were based on thermal measurements up to room temperature. These measurements also demonstrate the usefulness of internal friction as a tool for the study of these low-energy excitations, since internal friction is less sensitive to defects common to glass ceramics, like magnetic impurities and grain boundaries, which tend to dominate low-temperature specific heat and thermal conductivity, respectively.

X-ray photoelectron spectroscopy: a unique tool to determine the internal heterostructure of nanoparticles

We review the existing literature on the application of X-ray photoelectron spectroscopy in the study of nanocrystals. The unique ability of this technique to provide quantitative and reliable descriptions of highly complex internal structures of a variety of nanocrystals has been discussed in detail. We show that an accurate description of the nanocrystal internal structure is crucial and a prerequisite to understand many different properties, particularly optical properties, of such nanocrystal systems. We also discuss limitations and future outlook of this technique.

Internal noise-driven generalized Langevin equation from a nonlocal continuum model

Starting with a micropolar formulation, known to account for nonlocal microstructural effects at the continuum level, a generalized Langevin equation (GLE) for a particle, describing the predominant motion of a localized region through a single displacement degree of freedom, is derived. The GLE features a memory-dependent multiplicative or internal noise, which appears upon recognizing that the microrotation variables possess randomness owing to an uncertainty principle. Unlike its classical version, the present GLE qualitatively reproduces the experimentally measured fluctuations in the steady-state mean square displacement of scattering centers in a polyvinyl alcohol slab. The origin of the fluctuations is traced to nonlocal spatial interactions within the continuum, a phenomenon that is ubiquitous across a broad class of response regimes in solids and fluids. This renders the proposed GLE a potentially useful model in such cases.

Combustion and heat transfer characteristics of nanofluid fuel droplets: A short review

With the pressing need to meet an ever-increasing energy demand, the combustion systems utilizing fossil fuels have been the major contributors to carbon footprint. As the combustion of conventional energy resources continue to produce significant Green House gas (GHG) emissions, there is a strong emphasis to either upgrade or find an energy-efficient eco-friendly alternative to the traditional hydrocarbon fuels. With recent developments in nanotechnology, the ability to manufacture materials with custom tailored properties at nanoscale has led to the discovery of a new class of high energy density fuels containing reactive metallic nanoparticles (NPs). Due to the high reactive interfacial area and enhanced thermal and mass transport properties of nanomaterials, the high heat of formation of these metallic fuels can now be released rapidly, thereby saving on specific fuel consumption and hence reducing GHG emissions. In order to examine the efficacy of nanofuels in energetic formulations, it is imperative to first study their combustion characteristics at the droplet scale that form the fundamental building block for any combustion system utilizing liquid fuel spray. During combustion of such multiphase, multicomponent droplets, the phenomenon of diffusional entrapment of high volatility species leads to its explosive boiling (at the superheat limit) thereby leading to an intense internal pressure build-up. This pressure upsurge causes droplet fragmentation either in form of a microexplosion or droplet puffing followed by atomization (with formation of daughter droplets) featuring disruptive burning. Both these atomization modes represent primary mechanisms for extracting the high oxidation energies of metal NP additives by exposing them to the droplet flame (with daughter droplets acting as carriers of NPs). Atomization also serves as a natural mechanism for uniform distribution and mixing of the base fuel and enhancing burning rates (due to increase in specific surface area through formation of smaller daughter droplets). However, the efficiency of atomization depends on the thermo-physical properties of the base fuel, NP concentration and type. For instance, at dense loading NP agglomeration may lead to shell formation which would sustain the pressure upsurge and hence suppress atomization thereby reducing droplet gasification rate. Contrarily, the NPs may act as nucleation sites and aid boiling and the radiation absorption by NPs (from the flame) may lead to enhanced burning rates. Thus, nanoadditives may have opposing effects on the burning rate depending on the relative dominance of processes occurring at the droplet scale. The fundamental idea in this study is to: First, review different thermo-physical processes that occur globally at the droplet and sub-droplet scale such as surface regression, shell formation due to NP agglomeration, internal boiling, atomization/NP transport to flame zone and flame acoustic interaction that occur at the droplet scale and second, understand how their interaction changes as a function of droplet size, NP type, NP concentration and the type of base fuel. This understanding is crucial for obtaining phenomenological insights on the combustion behavior of novel nanofluid fuels that show great promise for becoming the next-generation fuels. (C) 2016 Elsevier Ltd. All rights reserved.

Internal models in the cerebellum.

This review will focus on the possibility that the cerebellum contains an internal model or models of the motor apparatus. Inverse internal models can provide the neural command necessary to achieve some desired trajectory. First, we review the necessity of such a model and the evidence, based on the ocular following response, that inverse models are found within the cerebellar circuitry. Forward internal models predict the consequences of actions and can be used to overcome time delays associated with feedback control. Secondly, we review the evidence that the cerebellum generates predictions using such a forward model. Finally, we review a computational model that includes multiple paired forward and inverse models and show how such an arrangement can be advantageous for motor learning and control.

A Review of Nontraditional Biomanipulation

The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels. Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.

Effectiveness and safety of cryotherapy after arthroscopic anterior cruciate ligament reconstruction. A systematic review of the literature

Cryotherapy is widely used in rehabilitation; however, its effectiveness after anterior cruciate ligament (ACL) reconstruction remains uncertain. To investigate the effectiveness and safety of cryotherapy following ACL reconstruction through a systematic review, randomized and quasi-randomized clinical trials were searched in the databases: MEDLINE, EMBASE, CENTRAL PEDro, SportDiscus, CINAHL, LILACS (June 2013). the primary outcomes measures were pain, edema and adverse events; the secondary outcomes were knee function, analgesic medication use, range of motion, blood loss, hospital stay, quality of life and patient satisfaction. the methodological quality of studies was evaluated using the Cochrane Collaboration risk-of-bias tool. Ten trials (a total of 573 patients) were included. Results of meta-analysis showed that the use of cold compression devices produced a significant reduction in pain scores 48 h after surgery (p < 0.00001), compared to no cryotherapy. the risk for adverse events did not differ between patients receiving cryotherapy versus no treatment (p = 1.00). the limited evidence currently available is insufficient to draw definitive conclusions on the effectiveness of cryotherapy for other outcomes. There is a need for well designed, good quality randomized trials to answer other questions related to this intervention and increase the precision of future systematic reviews. (C) 2014 Elsevier B.V. All rights reserved.

Review of inspection techniques based on the elastic and inelastic scattering of X-rays and their potential in the food and agricultural industry

C.R. Bull, R. Zwiggelaar and R.D. Speller, 'Review of inspection techniques based on the elastic and inelastic scattering of X-rays and their potential in the food and agricultural industry', Journal of Food Engineering 33 (1-2), 167-179 (1997)

Systematic review of worldwide variations of the prevalence of wheezing symptoms in children

Background: Considerable variation in the prevalence of childhood asthma and its symptoms (wheezing) has been observed in previous studies and there is evidence that the prevalence has been increasing over time. Methods: We have systematically reviewed the reported prevalence and time trends of wheezing symptoms among children, worldwide and within the same country over time. All studies comprising more than 1000 persons and meeting certain other quality criteria published over a 16-year period, between January 1990 and December 2005, are reported and a comparison of ISAAC (International Study of Asthma and Allergies in Childhood) and non-ISAAC studies is made, in part as a way of expanding the power to examine time trends (the older studies tend to be non-ISAAC), but also to examine possible methodological differences between ISAAC and non-ISAAC questions. Results: A wide range of current prevalence of wheeze was observed between and within countries over time. The UK had the highest recorded prevalence of 32.2% in children aged 13–14 in 1994–5 and Ethiopia had the lowest prevalence, 1.7% in children aged 10–19 in 1996. All studies in Australia and the UK were compared using multiple logistic regression. ISAAC phase I and III studies reported significantly higher prevalence of current wheeze (OR = 1.638) compared with non-ISAAC studies, after adjusting for various other factors (country, survey year, age of child, parental vs child response to the survey). Australia showed a significantly higher prevalence of current wheezing (OR = 1.343) compared with the UK, there was a significant increase in the prevalence odds ratio per survey year (2.5% per year), a significant decrease per age of child (0.7% per year), and a significantly higher response in current wheezing if the response was self-completed by the child (OR = 1.290). These factors, when explored separately for ISAAC and non-ISAAC studies, showed very different results. In ISAAC studies, or non-ISAAC studies using ISAAC questions, there was a significant decrease in current wheezing prevalence over time (2.5% per year). In non-ISAAC studies, which tend to cover an earlier period, there was a significant increase (2.6% per year) in current wheezing prevalence over time. This is very likely to be a result of prevalence of wheezing increasing from the 1970s up to the early 1990s, but decreasing since then. Conclusion: The UK has the highest recorded prevalence of wheezing and Ethiopia the lowest. Prevalence of wheezing in Australia and the UK has increased from the 1970s up to the early 1990s, but decreased since then and ISAAC studies report significantly higher prevalences than non-ISAAC studies.

Plastic and marine turtles: a review and call for research

Plastic debris is now ubiquitous in the marine environment affecting a wide range of taxa, from microscopic zooplankton to large vertebrates. Its persistence and dispersal throughout marine ecosystems has meant that sensitivity toward the scale of threat is growing, particularly for species of conservation concern, such as marine turtles. Their use of a variety of habitats, migratory behaviour, and complex life histories leave them subject to a host of anthropogenic stressors, including exposure to marine plastic pollution. Here, we review the evidence for the effects of plastic debris on turtles and their habitats, highlight knowledge gaps, and make recommendations for future research. We found that, of the seven species, all are known to ingest or become entangled in marine debris. Ingestion can cause intestinal blockage and internal injury, dietary dilution, malnutrition, and increased buoyancy which in turn can result in poor health, reduced growth rates and reproductive output, or death. Entanglement in plastic debris (including ghost fishing gear) is known to cause lacerations, increased drag—which reduces the ability to forage effectively or escape threats—and may lead to drowning or death by starvation. In addition, plastic pollution may impact key turtle habitats. In particular, its presence on nesting beaches may alter nest properties by affecting temperature and sediment permeability. This could influence hatchling sex ratios and reproductive success, resulting in population level implications. Additionally, beach litter may entangle nesting females or emerging hatchlings. Lastly, as an omnipresent and widespread pollutant, plastic debris may cause wider ecosystem effects which result in loss of productivity and implications for trophic interactions. By compiling and presenting this evidence, we demonstrate that urgent action is required to better understand this issue and its effects on marine turtles, so that appropriate and effective mitigation policies can be developed.