Water governance challenges presented by nanotechnologies: tracking, identifying and quantifying nanomaterials (the ultimate disparate source) in our waterways

2016 ◽  
Vol 47 (3) ◽  
pp. 552-568 ◽  
Author(s):  
Iseult Lynch

Nanotechnologies are considered an enabling technology, as they enhance the functioning of a wide range of products and processes. They are increasingly appearing in consumer products, including sun creams, socks and outdoor paints, resulting in the potential for direct access of nanomaterials (NMs) into wastewater and the environment. As such, they could be considered as the ultimate disparate source, with multiple products and multiple routes into the environment, as well as numerous transformation pathways, such that the final form may bear little resemblance to the initially produced form. NMs thus represent a significant governance and regulatory challenge, for a number of reasons, related to their small size, which makes detection challenging, especially against a background of naturally occurring nanoscale entities (clay and sediment particles, etc.), and their large surface area and high surface energy which leads to very dynamic behaviour and a strong tendency to interact with (bind) anything they come into contact with. Some initial considerations of regulatory issues related to Registration, Evaluation and Authorization of Chemicals, the Water Framework Directive, and the potential for benign-by-design approaches exploiting the potential for recovery or recycling of NMs at the design phase are presented, aimed at reducing the risk of unintentional accumulation of NMs in our waterways.

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1109
Author(s):  
Varnakavi. Naresh ◽  
Nohyun Lee

A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.


2021 ◽  
Vol 14 (6) ◽  
pp. 541
Author(s):  
Hani A. Alhadrami ◽  
Ahmed M. Sayed ◽  
Heba Al-Khatabi ◽  
Nabil A. Alhakamy ◽  
Mostafa E. Rateb

The COVID-19 pandemic is still active around the globe despite the newly introduced vaccines. Hence, finding effective medications or repurposing available ones could offer great help during this serious situation. During our anti-COVID-19 investigation of microbial natural products (MNPs), we came across α-rubromycin, an antibiotic derived from Streptomyces collinus ATCC19743, which was able to suppress the catalytic activity (IC50 = 5.4 µM and Ki = 3.22 µM) of one of the viral key enzymes (i.e., MPro). However, it showed high cytotoxicity toward normal human fibroblasts (CC50 = 16.7 µM). To reduce the cytotoxicity of this microbial metabolite, we utilized a number of in silico tools (ensemble docking, molecular dynamics simulation, binding free energy calculation) to propose a novel scaffold having the main pharmacophoric features to inhibit MPro with better drug-like properties and reduced/minimal toxicity. Nevertheless, reaching this novel scaffold synthetically is a time-consuming process, particularly at this critical time. Instead, this scaffold was used as a template to explore similar molecules among the FDA-approved medications that share its main pharmacophoric features with the aid of pharmacophore-based virtual screening software. As a result, cromoglicic acid (aka cromolyn) was found to be the best hit, which, upon in vitro MPro testing, was 4.5 times more potent (IC50 = 1.1 µM and Ki = 0.68 µM) than α-rubromycin, with minimal cytotoxicity toward normal human fibroblasts (CC50 > 100 µM). This report highlights the potential of MNPs in providing unprecedented scaffolds with a wide range of therapeutic efficacy. It also revealed the importance of cheminformatics tools in speeding up the drug discovery process, which is extremely important in such a critical situation.


2015 ◽  
Vol 14 (4) ◽  
pp. 118-123 ◽  
Author(s):  
Lauren Trees

Purpose – The purpose of this paper is to present enterprise social networking and gamification as two potential tools to help organizations engage Millennial employees in collaboration and learning. Design/methodology/approach – The research provides general descriptions of enterprise social networking and gamification approaches, shares data on adoption of these approaches from APQC’s “2015 Knowledge Management Priorities Data Report” (based on a January 2015 survey of 524 knowledge management professionals) and includes four company examples adapted from APQC’s Connecting People to Content and Transferring and Applying Critical Knowledge best practices studies. The methodology for APQC’s best practices studies involves screening 50 or more organizations with potential best practices in a given research scope area and identifying five or six with proven best practices. APQC then conducts detailed site visits with the selected organizations and publishes case studies based on those site visits. Findings – Enterprise social networking platforms are in place at 50 per cent of organizations, with another 25 per cent planning to implement them by the end of 2015. By providing near-immediate access to information and answers, enterprise social networking helps Millennials learn the ropes at their new workplaces, gives them direct access to more knowledgeable colleagues who can assist and mentor them, and helps them improve their business outcomes by reusing knowledge and lessons learned across projects. Younger workers can also harness the power of social networking to create a sense of belonging and build their reputations in large, dispersed firms, where it is particularly difficult for them to gain visibility. A recent APQC survey indicates that 54 per cent of organizations either currently employ gamification to encourage collaboration or expect to implement it within the next three years. The rush to gamify the enterprise is, at least in part, a reflection of employers’ desire to satisfy Millennials and make them feel connected to a community of co-workers. Although games appeal to a wide range of age groups, Millennials grew up with digital interaction and tend to prefer environments that emphasize teamwork, social learning and frequent feedback – all of which can be delivered through gamification. Originality/value – The value of this paper is to introduce the value of and relationship between enterprise social networking and gamification platforms to human resource (HR) professionals looking to increase engagement and retention rates for Millennial employees.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Adnan Haider ◽  
Inn-Kyu Kang

Silver nanoparticles (Ag-NPs) have diverted the attention of the scientific community and industrialist itself due to their wide range of applications in industry for the preparation of consumer products and highly accepted application in biomedical fields (especially their efficacy against microbes, anti-inflammatory effects, and wound healing ability). The governing factor for their potent efficacy against microbes is considered to be the various mechanisms enabling it to prevent microbial proliferation and their infections. Furthermore a number of new techniques have been developed to synthesize Ag-NPs with controlled size and geometry. In this review, various synthetic routes adapted for the preparation of the Ag-NPs, the mechanisms involved in its antimicrobial activity, its importance/application in commercial as well as biomedical fields, and possible application in future have been discussed in detail.


2021 ◽  
Vol 316 ◽  
pp. 794-802
Author(s):  
Andrey E. Balanovsky ◽  
Van Trieu Nguyen

The Purpose of paper is to conduct studies to assess the possibility of increasing the hardness of the surface layer of steel St3 grade by plasma heating of the applied surface coating containing powder alloy PR-N80X13S2R. Mixtures of pasta were divided into 2 groups: for furnace chemical-thermal treatment and plasma surface melting. The study of the microstructure showed a difference in the depth of the saturated layer, depending on the processing method, during chemical-thermal treatment-1 mm, plasma fusion - 2 mm. The results of measuring the surface micro-hardness showed that, the obtained coating from a mixture of PR-N80X13S2R + Cr2O3 + NH4Cl has a uniform high surface hardness (31-64 HRC), from a mixture of only PR-N80X13S2R - the surface hardness varies in a wide range (15-60 HRC). The study of the microhardness of the cross section of the surface layer showed that, the diffusion region: from a mixture of powder PR-N80X13S2R + Cr2O3 + NH4Cl has uniform hardness (450-490 HV); from a mixture of PR-N80X13S2R - hardness increases in the depth of the molten region (from 300 to 600 HV), and sharply decreases in the heat affected zone (210-170 HV). The use of PR-N80X13S2R alloy powder as the main component in the composition of the paste deposited on the St3 surface during plasma treatment leads to the formation of a doped surface layer with high hardness.


Author(s):  
Sally Babidge

Water governance refers to the material and regulatory control of water and waters. It involves questions such as who makes decisions about water and how; at what scale such decisions are made in relation to different waters; and who and which water or ecosystem benefits. Classical work in anthropology considered how irrigation practices may have given rise to the development of state forms, and in response to early-21st-century privatization regimes, anthropologists have considered how different groups have challenged the apparent global dominance of commodity values and water as property. Infrastructures for water distribution in urban areas (such as systems of canals, pipes, and faucets), and considerations of the sociocultural effects of hydrological unit delineation and definition (e.g., groundwater or river “basins”) have become key sites for the ethnographic investigation of water governance, emerging forms of personhood, and societal inequalities. The diversity in anthropologies of water unsettles generalized models in global regimes of water governance. The anthropology of water governance and ownership considers the context and contingencies of water and power. It reveals the global dominance of markets, rights, and technical approaches to water management, such as the case of “private water” in Chile, in which water markets have failed to provide equity and environmental health, but also how certain groups avoided complete privatization of water under this extreme example. Ethnographic studies of the cultural organization of resource scarcity over topographically complex and remote terrain, such as that of irrigators in the Andean cordillera, express the diversity of human innovation at the intersection of politics and ecology. In arid South Eastern Australia, basin plans that treat water as a unit of calculation and economic trade place social and ecological relations in peril. Infrastructures of development provide a narrative of unsettled state and development ideologies, and the problem of groundwater management reveals governance challenges in the face of unstable, unknown, and invisible material. Anthropological studies of water contribute to knowledge of earth’s diverse humanity, knowledge practices, and ecologies. Researchers propose that water governance might engage with human differences articulated at multiple scales, as well as in understanding water’s material agency and waters as dynamic, especially in an ever-changing climate.


Author(s):  
Guru Venkatesan ◽  
Andy Sarles

Droplet-based biomolecular arrays form the basis for a new class of bioinspired material system, whereby decreasing the sizes of the droplets and increasing the number of droplets can lead to higher functional density for the array. In this paper, we report on a non-microfluidic approach to form and connect nanoliter-to-femtoliter, lipid-coated aqueous droplets in oil to form micro-droplet interface bilayers (μDIBs). Two different modes of operation are reported for dispensing a wide range of droplet sizes (2–200μm radius). Due to the high surface-area-to-volume ratios of microdroplets at these length scales, droplet shrinking is prominent, which affects the stability and lifetime of the bilayer. To better quantify these effects, we measure the shrinkage rates for 8 different water droplet/oil compositions and study the effect of lipid placement and lipid type on morphological changes to μDIBs.


2018 ◽  
Vol 2 (4) ◽  
pp. 74 ◽  
Author(s):  
Abinash Tripathy ◽  
Patryk Wąsik ◽  
Syama Sreedharan ◽  
Dipankar Nandi ◽  
Oier Bikondoa ◽  
...  

Functional ZnO nanostructured surfaces are important in a wide range of applications. Here we report the simple fabrication of ZnO surface structures at near room temperature with morphology resembling that of sea urchins, with densely packed, μm-long, tapered nanoneedles radiating from the urchin center. The ZnO urchin structures were successfully formed on several different substrates with high surface density and coverage, including silicon (Si), glass, polydimethylsiloxane (PDMS), and copper (Cu) sheets, as well as Si seeded with ZnO nanocrystals. Time-resolved SEM revealed growth kinetics of the ZnO nanostructures on Si, capturing the emergence of “infant” urchins at the early growth stage and subsequent progressive increases in the urchin nanoneedle length and density, whilst the spiky nanoneedle morphology was retained throughout the growth. ε-Zn(OH)2 orthorhombic crystals were also observed alongside the urchins. The crystal structures of the nanostructures at different growth times were confirmed by synchrotron X-ray diffraction measurements. On seeded Si substrates, a two-stage growth mechanism was identified, with a primary growth step of vertically aligned ZnO nanoneedle arrays preceding the secondary growth of the urchins atop the nanoneedle array. The antibacterial, anti-reflective, and wetting functionality of the ZnO urchins—with spiky nanoneedles and at high surface density—on Si substrates was demonstrated. First, bacteria colonization was found to be suppressed on the surface after 24 h incubation in gram-negative Escherichia coli (E. coli) culture, in contrast to control substrates (bare Si and Si sputtered with a 20 nm ZnO thin film). Secondly, the ZnO urchin surface, exhibiting superhydrophilic property with a water contact angle ~ 0°, could be rendered superhydrophobic with a simple silanization step, characterized by an apparent water contact angle θ of 159° ± 1.4° and contact angle hysteresis ∆θ < 7°. The dynamic superhydrophobicity of the surface was demonstrated by the bouncing-off of a falling 10 μL water droplet, with a contact time of 15.3 milliseconds (ms), captured using a high-speed camera. Thirdly, it was shown that the presence of dense spiky ZnO nanoneedles and urchins on the seeded Si substrate exhibited a reflectance R < 1% over the wavelength range λ = 200–800 nm. The ZnO urchins with a unique morphology fabricated via a simple route at room temperature, and readily implementable on different substrates, may be further exploited for multifunctional surfaces and product formulations.


2021 ◽  
Author(s):  
Nuray Kizildag

Ceramic materials are well known for their hardness, inertness, superior mechanical and thermal properties, resistance against chemical erosion and corrosion. Ceramic nanofibers were first manufactured through a combination of electrospinning with sol–gel method in 2002. The electrospun ceramic nanofibers display unprecedented properties such as high surface area, length, thermo-mechanical properties, and hierarchically porous structure which make them candidates for a wide range of applications such as tissue engineering, sensors, water remediation, energy storage, electromagnetic shielding, thermal insulation materials, etc. This chapter focuses on the most recent advances in the applications of ceramic nanofibers.


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