scholarly journals PtOEP–PDMS-Based Optical Oxygen Sensor

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5645
Author(s):  
Camila M. Penso ◽  
João L. Rocha ◽  
Marcos S. Martins ◽  
Paulo J. Sousa ◽  
Vânia C. Pinto ◽  
...  
Keyword(s):  
Oxygen Sensor ◽  
Low Cost ◽  
Chemical Properties ◽  
Cost Effective ◽  
Luminescent Properties ◽  
Low Oxygen ◽  
Pdms Film ◽  
Sensing Applications ◽  
Optical Oxygen Sensor

The advanced and widespread use of microfluidic devices, which are usually fabricated in polydimethylsiloxane (PDMS), requires the integration of many sensors, always compatible with microfluidic fabrication processes. Moreover, current limitations of the existing optical and electrochemical oxygen sensors regarding long-term stability due to sensor degradation, biofouling, fabrication processes and cost have led to the development of new approaches. Thus, this manuscript reports the development, fabrication and characterization of a low-cost and highly sensitive dissolved oxygen optical sensor based on a membrane of PDMS doped with platinum octaethylporphyrin (PtOEP) film, fabricated using standard microfluidic materials and processes. The excellent mechanical and chemical properties (high permeability to oxygen, anti-biofouling characteristics) of PDMS result in membranes with superior sensitivity compared with other matrix materials. The wide use of PtOEP in sensing applications, due to its advantage of being easily synthesized using microtechnologies, its strong phosphorescence at room temperature with a quantum yield close to 50%, its excellent Strokes Shift as well as its relatively long lifetime (75 µs), provide the suitable conditions for the development of a miniaturized luminescence optical oxygen sensor allowing long-term applications. The influence of the PDMS film thickness (0.1–2.5 mm) and the PtOEP concentration (363, 545, 727 ppm) in luminescent properties are presented. This enables to achieve low detection levels in a gas media range from 0.5% up to 20%, and in liquid media from 0.5 mg/L up to 3.3 mg/L at 1 atm, 25 °C. As a result, we propose a simple and cost-effective system based on a LED membrane photodiode system to detect low oxygen concentrations for in situ applications.

Building Evaluation Capital in Government: A Queensland Departmental Approach

2017 ◽  
Vol 17 (4) ◽  
pp. 39-49
Author(s):  
Sarah Goswami ◽  
Vicki Lane
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Building Blocks ◽  
Decision Makers ◽  
Value For Money ◽  
Department Of Agriculture ◽  
Evaluation Capacity Building ◽  
Statutory Body

Increasingly, government departments are being held accountable for investment in public services. In Queensland the Financial Accountability Act 2009 (Queensland Treasury, 2016) requires that accountable officers and statutory bodies ‘achieve reasonable value for money by ensuring the operations of the department or statutory body are carried out efficiently, effectively and economically’ (Section 61). Whilst there is a directive for agencies to evaluate and demonstrate value for money, it has in practice been difficult to embed long term, as many systems and decision makers have neglected the role of organisation-wide evaluation capital. This paper will outline the work being undertaken in the Queensland Department of Agriculture and Fisheries (DAF) to implement an Impact and Investment Framework, which will support and embed evaluation in a multidisciplinary setting. A central tenant of this framework is ‘business empowerment and learning'—building the evaluation culture in the organisation by first establishing evaluation building blocks, through business empowerment, support and utility. The framework is comprised of five key elements and is built on the principles of evaluation and evaluation capacity building disciplines. It has been designed to be low-cost, effective and efficient, whilst enabling business improvement, meeting accountability needs and allowing the department to demonstrate the value of its work.

The Research about La0.8Sr0.2CoO3 Application as Dense Diffusion Barrier in Limiting Current Oxygen Sensors

2013 ◽  
Vol 703 ◽  
pp. 111-114
Author(s):  
Yin Lin Wu ◽  
Hai Yan Zhao ◽  
Fu Shen Li
Keyword(s):  
Diffusion Barrier ◽  
Solid Electrolytes ◽  
Oxygen Sensor ◽  
Low Cost ◽  
Limiting Current ◽  
Stabilized Zirconia ◽  
Long Term Stability ◽  
Oxygen Ion ◽  
Ion Conducting

The fabrication and operation of a new thick film type of limiting current oxygen sensor is demonstrated that utilizes yttria (8% mol) stabilized zirconia (YSZ) as oxygen ion conducting solid electrolytes and dense La0.8Sr0.2CoO3(LSC) as diffusion barrier. The oxygen sensor shows a near linear response between 0 to 10.5% O2in argon at 1023K. The advantages of the sensor are simple construction, low cost and potential long term stability.

Mitigation of emerging pollutants by plants

2011 ◽  
Vol 6 (4) ◽  
Author(s):  
D. Reinhold ◽  
N. Aryal
Keyword(s):  
Wastewater Treatment ◽  
Surface Waters ◽  
Low Cost ◽  
Cost Effective ◽  
Emerging Pollutants ◽  
Food Crops ◽  
Minimal Risk ◽  
Sustainable Technologies ◽  
Trace Concentrations

Low cost, sustainable technologies for addressing pollution of waters with trace concentrations of pharmaceuticals and personal care products (PPCPs) are needed. Plant-based ecosystems for wastewater treatment are low-cost, effective technologies with the potential to address PPCPs. This abstract presents recent research examining the phytoremediation of PPCPs in both aquatic and terrestrial systems and discusses potential implications of phytoremediation of PPCPs. Research indicates that duckweed plants can stimulate microbial degradation of ibuprofen, sorb and uptake fluoxetine, and indirectly affect the fate of triclosan. Additionally, research indicates that food crops phytoaccumulate antimicrobials present in biosolids. The implications of these processes include mitigation of ecotoxicological risk from antimicrobial contamination of surface waters and soils with minimal risk to humans from consumption of phytoaccumulated antimicrobials. Additionally, plants may serve as a long-term reservoir for PPCPs in the environment.

Limiting Current Oxygen Sensors with LSM as Dense Diffusion Barrier

2008 ◽  
Vol 368-372 ◽  
pp. 263-264
Author(s):  
Yin Lin Wu ◽  
Ling Wang ◽  
Fu Shen Li ◽  
Yan Qin Zhao
Keyword(s):  
Diffusion Barrier ◽  
Solid Electrolytes ◽  
Oxygen Sensor ◽  
Low Cost ◽  
Limiting Current ◽  
Excellent Performance ◽  
Long Term Stability ◽  
Oxygen Ion ◽  
Ion Conducting

A thick film type of limiting current oxygen sensor which uses yttria (8% mol) stabilized zirconia (YSZ) as oxygen ion conducting solid electrolytes and dense La0.8Sr0.2MnO3 (LSM) as diffusion barrier was developed successfully. The oxygen sensor showed excellent performance at oxygen concentrations ranging from 0 to 10 ppm. The advantages of the sensor are simple construction, low cost and potential long term stability.

scholarly journals Impact of Physico-Chemical Properties of Cellulose Nanocrystal/Silver Nanoparticle Hybrid Suspensions on Their Biocidal and Toxicological Effects

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1862
Author(s):  
Dafne Musino ◽  
Julie Devcic ◽  
Cécile Lelong ◽  
Sylvie Luche ◽  
Camille Rivard ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Low Cost ◽  
Aqueous Suspension ◽  
Chemical Properties ◽  
Molar Ratio ◽  
Biocidal Activity ◽  
Phagocytic Capacity ◽  
Toxicological Effects ◽  
Physico Chemical

There is a demand for nanoparticles that are environmentally acceptable, but simultaneously efficient and low cost. We prepared silver nanoparticles (AgNPs) grafted on a native bio-based substrate (cellulose nanocrystals, CNCs) with high biocidal activity and no toxicological impact. AgNPs of 10 nm are nucleated on CNCs in aqueous suspension with content from 0.4 to 24.7 wt%. XANES experiments show that varying the NaBH4/AgNO3 molar ratio affects the AgNP oxidation state, while maintaining an fcc structure. AgNPs transition from 10 nm spherical NPs to 300 nm triangular-shaped AgNPrisms induced by H2O2 post-treatment. The 48 h biocidal activity of the hybrid tested on B. Subtilis is intensified with the increase of AgNP content irrespective of the Ag+/Ag0 ratio in AgNPs, while the AgNSphere−AgNPrism transition induces a significant reduction of biocidal activity. A very low minimum inhibitory concentration of 0.016 mg AgNP/mL is determined. A new long-term biocidal activity test (up to 168 h) proved efficiency favorable to the smaller AgNPs. Finally, it is shown that AgNPs have no impact on the phagocytic capacity of mammalian cells.

scholarly journals MIRRA: A Modular and Cost-Effective Microclimate Monitoring System for Real-Time Remote Applications

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4615
Author(s):  
Olivier Pieters ◽  
Emiel Deprost ◽  
Jonas Van Der Donckt ◽  
Lore Brosens ◽  
Pieter Sanczuk ◽  
...  
Keyword(s):  
Climate Change ◽  
Real Time ◽  
Monitoring System ◽  
Low Cost ◽  
Cost Effective ◽  
Time Data ◽  
Real Time Data ◽  
Microclimate Monitoring ◽  
Weather Stations

Monitoring climate change, and its impacts on ecological, agricultural, and other societal systems, is often based on temperature data derived from official weather stations. Yet, these data do not capture most microclimates, influenced by soil, vegetation and topography, operating at spatial scales relevant to the majority of organisms on Earth. Detecting and attributing climate change impacts with confidence and certainty will only be possible by a better quantification of temperature changes in forests, croplands, mountains, shrublands, and other remote habitats. There is an urgent need for a novel, miniature and simple device filling the gap between low-cost devices with manual data download (no instantaneous data) and high-end, expensive weather stations with real-time data access. Here, we develop an integrative real-time monitoring system for microclimate measurements: MIRRA (Microclimate Instrument for Real-time Remote Applications) to tackle this problem. The goal of this platform is the design of a miniature and simple instrument for near instantaneous, long-term and remote measurements of microclimates. To that end, we optimised power consumption and transfer data using a cellular uplink. MIRRA is modular, enabling the use of different sensors (e.g., air and soil temperature, soil moisture and radiation) depending upon the application, and uses an innovative node system highly suitable for remote locations. Data from separate sensor modules are wirelessly sent to a gateway, thus avoiding the drawbacks of cables. With this sensor technology for the long-term, low-cost, real-time and remote sensing of microclimates, we lay the foundation and open a wide range of possibilities to map microclimates in different ecosystems, feeding a next generation of models. MIRRA is, however, not limited to microclimate monitoring thanks to its modular and wireless design. Within limits, it is suitable or any application requiring real-time data logging of power-efficient sensors over long periods of time. We compare the performance of this system to a reference system in real-world conditions in the field, indicating excellent correlation with data collected by established data loggers. This proof-of-concept forms an important foundation to creating the next version of MIRRA, fit for large scale deployment and possible commercialisation. In conclusion, we developed a novel wireless cost-effective sensor system for microclimates.

scholarly journals Hazardous Components of Landfill Leachates and Its Bioremediation

2021 ◽  
Author(s):  
Menaka Salam ◽  
Namdol Nilza
Keyword(s):  
Organic Compounds ◽  
Biological Treatment ◽  
Low Cost ◽  
Chemical Properties ◽  
Industrial Effluents ◽  
Physical Method ◽  
Cost Effective ◽  
Toxic Substances ◽  
Landfill Leachates ◽  
Assessment And Treatment

Landfill leachates contain both dissolved and suspended material and may pose a threat to the environment because of the toxic substances that it carries and contaminates surface water and groundwater. They are composed of several different categories of components out of which many of them are recalcitrant and highly toxic. Major components of landfill leachates are dissolved organic compounds, inorganic macro compounds, heavy metals such as copper, lead, cadmium, chromium, nickel etc. and xenobiotic compounds such as polychlorinated biphenyls. Complex organic compounds which are released from industrial effluents like perfluorooctanoic acid and benzothiazole are also common in many of the landfill leachates. Biological treatment is a low cost effective method for the treatment of landfill leachates which can act as an accelerator for further treatment by either chemical or physical method. Improved strategies have been developed in the biological treatment of leachates which shows the efficiency of the system. But, as leachate characteristics vary depending on the rainfall and other environmental factors, it is important to first thoroughly analyze the physical and chemical properties of the landfill under study. A combined effort involving proper analysis of the leachate components, monitoring leachate flow, risk assessment, and treatment of the leachate before its release is required to efficiently control its impact to the environment.

SEM Evaluation of Chemically Finished Nonwoven Fabrics from Recycled Fibers

2000 ◽  
Vol 6 (S2) ◽  
pp. 770-771
Author(s):  
W. R. Goynes ◽  
E. E. Graves ◽  
W. Tao ◽  
G. F. D'Anna ◽  
M. P. Day ◽  
...  
Keyword(s):  
Textile Industry ◽  
Low Cost ◽  
Cost Effective ◽  
Economic Benefits ◽  
Health Care Facilities ◽  
Nonwoven Fabrics ◽  
Care Facilities ◽  
Emergency Housing ◽  
Recycled Fibers

The textile industry produces large quantities of waste and scrap materials. Most of this waste requires disposal. Both environmental and economic benefits could be derived by developing commercial products to use these materials. Environmentally acceptable textile products include those that utilize recycled materials, or materials that have not been chemically processed. Such products are often not economically profitable because of the added expense necessary for environmental protection. Development of such a cost-effective textile product requires use of low-cost materials, minimal cost production processes, and finishes that have already been developed and tested.The objective of this research was to develop a semi-disposable, economical, light-weight, comfortable thermal blanket that would be both flame-resistant and antibacterial through a limited number of laundry cycles. Targeted uses would be in medical and health care facilities, disaster relief centers, short term and emergency housing needs, recreational areas such as camping, and in military maneuvers where environmental conditions could be harmful to long-term products.

scholarly journals A fluorescent dissolved oxygen sensor with autocalibration based on ruthenium (II) tris-bathophenanthroline complex

2021 ◽  
Vol 2131 (5) ◽  
pp. 052094
Author(s):  
P Plyaka ◽  
O Demekhin ◽  
D Svetlichnyy ◽  
A Zagrebaev ◽  
A Budnik
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Sensor ◽  
Low Cost ◽  
Red Light ◽  
Inorganic Ions ◽  
Sensing Element ◽  
Green Approach ◽  
Red Led ◽  
Aquaculture Facilities

Abstract The study describes a submersible fluorescent dissolved oxygen (DO) sensor suitable for aquaculture facilities. The sensor is based on the quenching of fluorescence from ruthenium (II) tris-bathophenanthroline complex, [Ru(dpp)3]2+. One of its precursors, bathophenanthroline (BPhen), was obtained by a green approach with less aggressive reagents than in a classical synthesis. It was embedded in a polymer membrane and attached to a glass window to fabricate a sensing element. The composition and functioning of the sensor are described. It uses an additional red LED for automatic calibration and correction of measurements due to photodegradation of Ru(dpp) over time. The intensity of the red light reflected from the active Ru(II) centres indicates their concentration and allows for automatic correction of the calibration factor. The sensor has demonstrated good linearity in calibration tests; its readings were independent of the presence of common inorganic ions in water, which might interfere with the results. This novel low-cost sensor with autocalibration is expected to be a long-term solution for aquaculture.

scholarly journals Separation and enrichment of sodium-motile bacteria using cost-effective microfluidics

2020 ◽  
Author(s):  
Jyoti P Gurung ◽  
Moein Navvab Kashani ◽  
Sanaz Agarwal ◽  
Murat Gel ◽  
Matthew AB Baker
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Flagellar Motor ◽  
Term Selection ◽  
E Coli ◽  
Fold Enrichment ◽  
Torque Generation ◽  
Motile Species ◽  
Motile Bacteria

AbstractMany motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through the stator complex, with the next most common ionic power source being sodium. Synthetic chimeric stators which combine sodium- and proton-powered stators have enabled the interrogation of sodium-stators in species that are typically proton-powered, such as the sodium powered PomA-PotB stator complex in E. coli. Much is known about the signalling cascades that respond to attractant and govern switching bias as an end-product of chemotaxis, however less is known about how energetics and chemotaxis interact to affect the colonisation of environmental niches where ion concentrations and compositions may vary. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria. We measure separation efficiencies at varying ionic concentrations and confirm using fluorescence that our device can deliver eight-fold enrichment of the motile proportion of a mixed population of motile and non-motile species. Furthermore, our results show that we can select bacteria from reservoirs where sodium is not initially present. Overall, this technique can be used to implement long-term selection from liquid culture for directed evolution approaches to investigate the adaptation of motility in bacterial ecosystems.

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