Development of a simple, low cost chronoamperometric assay for fructose based on a commercial graphite-nanoparticle modified screen-printed carbon electrode

© 2017 Elsevier Ltd This paper describes the development of a simple, low cost chronoamperometric assay, for the measurement of fructose, using a graphite-nanoparticle modified screen-printed electrode (SPCE-G-COOH). Cyclic voltammetry showed that the response of the SPCE-G-COOH enhanced the sensitivity and precision, towards the enzymatically generated ferrocyanide species, over a plain SPCE; therefore the former was employed in subsequent studies. Calibration studies were carried out using chronoamperometry with a 40 µl mixture containing fructose, mediator and FDH, deposited onto the SPCE-G-COOH. The response was linear from 0.1 mM to 1.0 mM. A commercial fruit juice sample was analysed using the developed assay and the fructose concentration was calculated to be 477 mM with a precision of 3.03% (n = 5). Following fortification (477 mM fructose) the mean recovery was found to be 97.12% with a coefficient of variation of 6.42% (n = 5); consequently, the method holds promise for the analysis of commercial fruit juices

Impact of design parameters on the dynamic response and fatigue of offshore jacket foundations

The lifetime of offshore foundations is governed by a combination of harsh environmental conditions and complex service loads. The fatigue limit state (FLS) analysis needs to be performed in the time domain to capture the complex phenomenon. This study aims to investigate different parameters and design modifications that can impact the design life of an offshore jacket foundation. An OC4 jacket foundation is designed in industrial software from DNV and reduced to a super-element model. The super-element model is connected to an NREL 5-MW wind turbine designed in Bladed. The time-series loads are used to compute the fatigue damages faced by the foundation during the service life. The impact of soil non-linearity, marine growth, scour size, the mass of the transition piece, and the grouted connection’s design on the dynamic response and fatigue damages are compared. A 30% increase in life was observed by replacing the concrete transition piece with a lightweight steel configuration. The fatigue damages were considerably greater for the inclined pile in the leg grouted connection than for the leg in the pile concept. The study provides a different perspective by analysing the effect of design parameters and design changes in the complex and computationally expensive time-series domain

Biorenewable materials for water remediation:The central role of cellulose in achieving sustainability

As the population increases and manufacturing grows, greenhouse gas and other harmful emissions increase. Contaminated with chemicals such as dyes, pesticides, pharmaceuticals, oil, heavy metals or radionuclides, wastewater purification has become an urgent issue. Various technologies exist that can remove these contaminants from wastewater sources, but they often demand high energy and/or high cost, and in some cases produce contaminant laden sludge that requires safe disposal. The need for methods which are less capital intensive, less operationally costly and more environmentally friendly is suggested. Cellulose-based materials have emerged as promising candidates for wastewater treatment due to their renewability, low cost, biodegradability, hydrophilicity, and antimicrobial property. In this review article, we focussed on developing sustainable and biodegradable cellulose-based materials for wastewater treatment. This article deals with cellulose-based materials’ scope and their conversion into valuable products like hydrogel, aerogel, cellulose composites, and nanocellulose. The cellulose-based materials have no harmful environmental impact and are plentiful. The modified cellulose-based materials applying as membrane, adsorbent, sorbent, and beads to purify the wastewater were discussed. Finally, the challenges and future prospects of cellulose-based materials for wastewater treatment were considered, emphasizing their potential to be sustainable and eco-friendly alternatives to traditional materials used in wastewater treatment.</p

Improving Data Infrastructure to Reduce Firearms Violence

In the fall of 2020, Arnold Ventures, a philanthropy dedicated to maximizing opportunity and minimizing injustice, and NORC at University of Chicago, an objective nonpartisan research institution, released the Blueprint for a US Firearms Infrastructure (Roman, 2020). The Blueprint is the consensus report of an expert panel of distinguished academics, trailblazing practitioners, and government leaders. It describes 17 critical reforms required to modernize how data about firearms violence of all types (intentional, accidental, and self-inflicted) are collected, integrated and disseminated. This project, which is also supported by Arnold Ventures, takes the conceptual priorities described in the Blueprint and proposes specific new steps for implementation.The first step in building a better firearms data infrastructure is to acknowledge where we currently stand. In The State of Firearm Data in 2019 (Roman, 2019), the expert panel found that while there are a substantial number of data sources that collect data on firearms violence, existing datasets and data collections are limited, particularly around intentional injuries. There is some surveillance data, but health data on firearms injuries are kept separately from data on crimes, and there are few straightforward ways to link those data. Data that provide context for a shooting--where the event took place, and what the relationship was between victim and shooter--are not available alongside data on the nature of injuries. Valuable data collections have been discontinued, data are restricted by policy, important data are not collected, data are often difficult to access, and contemporary data are often not released in a timely fashion or not available outside of specialized settings. As a result, researchers face vast gaps in knowledge and are unable to leverage existing data to build the evidence base necessary to adequately answer key policy questions and inform firearms policymaking.In the Blueprint, the expert panel developed a set of recommendations organized around a reconceptualization of how data are collected and who collects data. The broad themes from the Blueprint are as follows:Almost all surveillance data in health and criminal justice is generated locally. It is a high priority to provide information, technical assistance, implementation supports, and funding to state and local governments to improve their collections.Comprehensive monitoring of all federal data collections is needed to ensure that important data elements are being collected, data gaps are being addressed, and quality issues are quickly resolved.Timely dissemination of key data is important, including the development of guidelines to ensure consistency across collections and that resources are made available to speed reporting for collections with historical delays.Improvement is needed in strategic communication about the purpose and use of data to federal agencies, researchers and to the general public.The current report builds on the Blueprint by developing implementation guidance for key recommendations. Where the Blueprint included actionable recommendations, such as naming discontinued surveys that should be resurrected, this report develops specific recommendations for implementation. The report is centered on three topics that were the highest priority for the expert panel but that required additional research before guidance could be disseminated. The research findings from that additional investigation are reported here, and recommendations to facilitate implementation are described. The three topic areas are as follows:The creation of a nonfatal firearms injury databaseIncreasing the quality, availability, and usefulness of firearms data for research and policyPractical steps for building state capacity and infrastructure to use data for evidence-based decision-makin

A holistic risk management framework for renewable energy investments

Private investments are critical enablers to achieving energy access for over 770 million people worldwide. Despite decreasing capital costs, investments in renewable energy (RE) projects in developing countries are low due to unattractive risk-return profiles. Through understanding key risks drivers and their interactions, actionable insights can be drawn to mitigate investment risks, making energy more accessible. This paper reviews RE risks and methods used for risk assessment and mitigation for developed and developing countries with a focus on Sub-Saharan Africa countries (SSA). The review finds that while risk analysis and evaluation mainly employed semi-quantitative multicriteria decision analysis (MCDA) and system dynamics (SD) methods for developing countries, qualitative methods were used to identify mitigations. The methods assessed technical and economic risks at a minimum, while MCDA and SD methods can assess social, political, and policy risks. The efficacies of mitigations were tested using SD and quantitative methods such as agent-based modelling and Monte Carlo simulation. The paper further introduces a ‘holistic multi-dimensional investor risk management framework’ which can be used to identify actions to improve investment risks in a structured manner. The framework addresses four fundamental limitations observed in the existing literature, recognising that RE risks are complex and involve multidisciplinary perspectives having interactions and feedbacks with other risks, actors, and their actions. This review provides a valuable reference to investors, policymakers, and researchers, providing a catalogue of risks, methods deployed in literature, including a framework to identify impactful actions to improve risk levels

Chemically reactive membrane crystallisation reactor for CO2–NH3 absorption and ammonium bicarbonate crystallisation: Kinetics of heterogeneous crystal growth

The feasibility of gas-liquid hollow fibre membrane contactors for the chemical absorption of carbon dioxide (CO2) into ammonia (NH3), coupled with the crystallisation of ammonium bicarbonate has been demonstrated. In this study, the mechanism of chemically facilitated heterogeneous membrane crystallisation is described, and the solution chemistry required to initiate nucleation elucidated. Induction time for nucleation was dependent on the rate of CO2 absorption, as this governed solution bicarbonate concentration. However, for low NH3 solution concentrations, a reduction in pH was observed with progressive CO2 absorption which shifted equilibria toward ammonium and carbonic acid, inhibiting both absorption and nucleation. An excess of free NH3 buffered pH suitably to balance equilibria to the onset of supersaturation, which ensured sufficient bicarbonate availability to initiate nucleation. Following induction at a supersaturation level of 1.7 (3.3 M NH3), an increase in crystal population density and crystal size was observed at progressive levels of supersaturation which contradicts the trend ordinarily observed for homogeneous nucleation in classical crystallisation technology, and demonstrates the role of the membrane as a physical substrate for heterogeneous nucleation during chemically reactive crystallisation. Both nucleation rate and crystal growth rate increased with increasing levels of supersaturation. This can be ascribed to the relatively low chemical driving force imposed by the shift in equilibrium toward ammonium which suppressed solution reactivity, together with the role of the membrane in promoting counter-current diffusion of CO2 and NH3 into the concentration boundary layer developed at the membrane wall, which permitted replenishment of reactants at the site of nucleation, and is a unique facet specific to this method of membrane facilitated crystallisation. Free ammonia concentration was shown to govern nucleation rate where a limiting NH3 concentration was identified above which crystallisation induced membrane scaling was observed. Provided the chemically reactive membrane crystallisation reactor was operated below this threshold, a consistent (size and number) and reproducible crystallised reaction product was collected downstream of the membrane, which evidenced that sustained membrane operation should be achievable with minimum reactive maintenance intervention

Sensitivity analysis of design parameters for reliability assessment of offshore wind turbine jacket support structures

Offshore Wind Turbine (OWT) support structures are subjected to hostile environments, defined by highly stochastic loads and complex soil-structure interaction, and thus the need for a probabilistic approach towards design. The study carried out herein presents the sensitivity analysis of these inherent stochastic variables imposed on a complex OWT support structure via purpose-developed modular non-intrusive structural reliability assessment formulation. The results from this study reveal that the uncertainties in the wind speed is a structural design driving factor and the hydrodynamic load effects are secondary to this, for the ultimate (ULS) and Fatigue Limit States (FLS) while their relative sensitivities on the Serviceability Limit State (SLS) cannot be clearly distinguished but are seen to have a dominant impact. Also, it was inferred that incorporating correlation between the variables have a significant impact on the reliability of the structure in the ULS design

Systematic review of demand-side management strategies in power systems of developed and developing countries

Balancing electricity demand and supply remains a significant challenge for the power systems in developing countries, such as Nigeria. In Nigeria, there is a shortage of adequate power supply, and demand-side management (DSM) plays a minor role in the power balancing mechanism with load shedding being widely used. The paper aims to review and compare various existing and emerging DSM strategies in developing countries. An extensive and systematic review was conducted to evaluate potential solutions using DSM to increase the overall energy efficiency in the Nigerian electricity market. This study found that, although the technical and economic potentials of DSM vary in developed countries, the uptakes of DSM have been severely hampered hence preventing the full exploitation and utilisation of the full potential of DSM. The initiatives of a DSM model in Nigeria and other developing countries can play a significant role in addressing demand and supply challenges but an upgrade of the energy infrastructures, a reform of the market structure and the provision of financial incentives are required to allow for wide implementations of DSM strategies in developing countries

Isisfordia molnari sp. nov., a new basal eusuchian from the mid-Cretaceous of Lightning Ridge, Australia

The Australian Mesozoic crocodyliform record is sparse in comparison to other Gondwanan localities. A single formally-named taxon is known from this interval; Isisfordia duncani (Winton Formation, Albian–Turonian, Queensland). We present a previously undescribed crocodyliform braincase from the Griman Creek Formation (Cenomanian), New South Wales, which we assign to Isisfordia molnari sp. nov. Assignment to the genus is based on the possession of a newly-defined autapomorphy of Isisfordia: a broadly exposed prootic within the supratemporal foramen. A second autapomorphy of I. duncani (maximum diameter of the caudal aperture of the cranioquadrate siphonium approximately one-third the mediolateral width of the foramen magnum, with the lateral wall of the caudal aperture formed exclusively by the quadrate) may also be present in I. molnari; however, definitive recognition of this feature is marred by incomplete preservation. The new taxon is differentiated from I. duncani based on the absence of a median ridge on the parietal, and the lack of characteristic ridges on the parietal that form the medial margin of the supratemporal foramina. Reanalysis of a second specimen (the former holotype of the nomen dubium,‘Crocodylus (Bottosaurus) selaslophensis’) allows for its referral to the genus Isisfordia. Crucial to this reappraisal is the reinterpretation of the specimen as a partial maxilla, not the dentary as previously thought. This maxillary fragment possesses specific characteristics shared only with I. duncani; namely an alveolar groove. However, several key features differentiate the maxillary fragment from I. duncani, specifically the presence of continuous alveolar septa, the thickening of the medial alveolar rim, and the alveolar and crown base morphology. These findings constitute the first evidence of Isisfordia outside of the type locality and indicate its widespread occurrence on the freshwater floodplains along the eastern margin of the epeiric Eromanga Sea during the Albian–Cenomanian

Energy transition at local level: analyzing the role of peer effects and socio-economic factors on UK solar photovoltaic deployment

A growing literature highlights the presence of spatial differences in solar photovoltaic (PV) adoption patterns. Central to forward planning is an understanding of what affects PV growth, yet insights into the determinants of PV adoption in the literature are limited. What factors do drive the adoption at local level? Are the effects of these factors geographically uniform or are there nuances? What is the nature of these nuances? Existing studies so far use aggregate macro datasets with limited ability to capture the role of peer effects. This paper considers some established variables but also broadens the base of variables to try to identify new indicators relating to PV adoption. Specifically, it analyses domestic PV adoption in the UK at local level using data on the number of charities as a proxy to capture the opportunities to initiate social interactions and peer effects. A geographically weighted regression model that considers the spatially varying relationship between PV adoption and socio-economic explanatory variables reveals significantly more variability than the global regression. Our results show that charities and self-employment positively influence PV uptake while other socio-economic variables such as population density has bidirectional impacts