Search query: Nano‐photocatalytic materials: possibilities and challenges

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abstract: Semiconductor photocatalysis has received much attention as a potential solution to the worldwide energy shortage and for counteracting environmental degradation. This article reviews state of the art research activities in the field, focusing on the scientific and technological possibilities offered by photocatalytic materials. We begin with a survey of efforts to explore suitable materials and to optimize their energy band configurations for specific applications. We then examine the design and fabrication of advanced photocatalytic materials in the framework of nanotechnology. Many of the most recent advances in photocatalysis have been realized by selective control of the morphology of nanomaterials or by utilizing the collective properties of nano assembly systems. Finally, we discuss the current theoretical understanding of key aspects of photocatalytic materials. This review also highlights crucial issues that should be addressed in future research activities.
author_names: Hua Tong

Shuxin Ouyang

Yingpu Bi

Naoto Umezawa

Mitsutake Oshikiri

Jinhua Ye
title: Nano photocatalytic materials: possibilities and challenges.
venue: Advanced materials
year: 2012

author_names: Hua Tong

Shuxin Ouyang

Yingpu Bi

Naoto Umezawa

Mitsutake Oshikiri

Jinhua Ye
title: Nano photocatalytic Materials: Possibilities and Challenges
year: 2012

abstract: Photocatalysis is one of the most promising processes within catalysis, due to its increasing potential and the possibility of its being combined with renewable solar energy
author_names: Jose M Dona-Rodriguez

Elisenda Pulido Melian
title: Nano Photocatalytic Materials: Possibilities and Challenges
venue: Nanomaterials
year: 2021

abstract: Graphene based metal/metal oxide composites are attracted much interest and attention as promising entrant to available biomedical devices owing to their good stability and unique properties. The fame of Graphene oxide (GO) has been on the increase due to their several applications in the fields of super capacitor and storage devices, ionic conductors and Nano sized membranes. GO is used as light emitting material, which makes it particularly suitable for various medical applications like protein bio sensing and disease discovery, targeted drug delivery and antimicrobial materials are just some of the possibilities GO holds for the biomedical field. GO can easily be mixed with different polymers and other materials, and enhance properties of composite materials like tensile strength, elasticity, conductivity and more. In this present review, discussed thoroughly with graphene based metal/metal oxide composites are used for different applications like antibacterial, antimicrobial, and biomedical etc. In future we expect fine control of the quantity of RGOhybrids is an important challenge to control toxicity.
author_names: and Gurumallesh
title: A Review on Graphene Based Metal/Metal Oxide Composites and Enhanced Properties along with Biomedical Applications
year: 2021

abstract: Additive manufacturing (AM) includes a series of techniques used to create products, in several different materials, such as metal, polymer or ceramics, with digital models. The main advantage of AM is that it allows the creation of complex structures, but AM promises several additional advantages including the possibility to manufacture on demand or replacing smaller worn parts by directly building on an existing piece. Therefore, the interest for and establishment of AM is rapidly expanding, which is positive, however it is important to be aware that new techniques may also result in new challenges regarding health and safety issues. Metals in blood and possible clinical effects due to metal exposure were investigated in AM operators at one of the first serial producing AM facilities in the world during two consecutive years with implementation of preventive measures in between. As comparison, welders and office workers as control group were investigated. Health investigations comprised of surveys, lung function tests, antioxidant activity and vascular inflammation as well as renal and hepatic function analysis. AM operators had significantly reduced nickel levels in blood (10.8 vs 6.2 nmol/L) as well as improved lung function (80 vs 92% of predicted) from year 1 to year 2. This is in line with previously published results displaying reduced exposure. Blood cobalt and nickel levels correlated with previously reported urinary levels, while blood chromium did not. Multivariate modelling showed that blood cobalt, antioxidant/inflammatory marker serum amyloid A1/serum paraoxonase/arylesterase 1 activity and the hepatic markers aspartate transaminase, alanine transaminase, and alkaline phosphatase were higher in AM operators compared to controls. The study show that the selected clinical analyses could function as a complement to metal analyses in biological fluids when investigating exposure related health effects in AM operators. However, validation in larger cohorts is necessary before more definite conclusions could be drawn.
author_names: Stefan A Ljunggren

Liam J Ward

Pal Graff

Anders Persson

Malin Leijon Lind

Helen Karlsson
title: Metal additive manufacturing and possible clinical markers for the monitoring of exposure related health effects
venue: PloS one
year: 2021

abstract: Emerging online arenas offer new possibilities for the study of online communication aided by computer assisted methods of data collection. However, these possibilities also entail certain challenges. As online data collection such as "scraping" of web content becomes part of the methodological repertoire of non technically inclined researchers, and as the data available for researchers to place under scrutiny grows ever more plentiful, we point to two challenges that need to be tackled if we are to grasp current developments. How can we make sense of the massive amounts of novel forms of mediated communication, and how can we approach them in an ethically sound manner? While all branches of media and communication research face these challenges, we are specifically interested in discussing them in relation to the broad field of political communication. Political communication research tries to understand and explain all forms of "purposeful communication about politics" (McNair 2003: 23) To do so, researchers have sampled newspaper articles, studied a selection of television broadcasts, analysed documentaries, or listened in on specific radio programmes. In the age of the mass media, these were perfectly legitimate approaches and they still are. Yet political communication research has had to expand its arsenal of approaches. During the roughly 15 years that have passed since the Web emerged as a mainstream platform for mediated communication, researchers have tried to grasp its effect on political communication. The majority of such work, however, notably relies on traditional methodological approaches. If we wish to properly understand online political communication, we need to explore novel possibilities. To assess the importance of blog posts, twitter messages and other so called social media outlets as platforms for political expression, to take one pertinent example, we first need to get an overview of the different types of these mediated forms of expression in our polity. This does not only entail intricate definitional delimitations, but also a some what daunting methodological task. Those trying to get an overview of the online communication during the latest Swedish election, for instance, would find a lot of material too much even to get a perspective on, perhaps. The number of messages or utterances users of one not very widespread service (Twitter) themselves labelled #val2010" "election2010" amounted to over 100,000 during a one month period leading up to the election. Still, empirical endeavours based on such data constitute necessary steps on the way forward for political communication research. And they clearly entail some challenges.
author_names: Hallvard Moe

Anders Olof Larsson
title: Methodological and Ethical Challenges Associated with Large scale Analyses of Online Political Communication
year: 2013

abstract: Excited state dynamics simulations are a powerful tool to investigate photo induced reactions of molecules and materials and provide complementary information to experiments. Since the applicability of these simulation techniques is limited by the costs of the underlying electronic structure calculations, we develop and assess different machine learning models for this task. The machine learning models are trained on \emph ab initio} calculations for excited electronic states, using the methylenimmonium cation (CH$_2$NH$_2^ as a model system. For the prediction of excited state properties, multiple outputs are desirable, which is straightforward with neural networks but less explored with kernel ridge regression. We overcome this challenge for kernel ridge regression in the case of energy predictions by encoding the electronic states explicitly in the inputs, in addition to the molecular representation. We adopt this strategy also for our neural networks for comparison. Such a state encoding enables not only kernel ridge regression with multiple outputs but leads also to more accurate machine learning models for state specific properties. An important goal for excited state machine learning models is their use in dynamics simulations, which needs not only state specific information but also couplings, i.e. properties involving pairs of states. Accordingly, we investigate the performance of different models for such coupling elements. Furthermore, we explore how combining all properties in a single neural network affects the accuracy. As an ultimate test for our machine learning models, we carry out excited state dynamics simulations based on the predicted energies, forces and couplings and, thus, show the scopes and possibilities of machine learning for the treatment of electronically excited states.
author_names: Julia Westermayr

Felix A Faber

Anders S Christensen

O Anatole von Lilienfeld

Philipp Marquetand
title: Neural networks and kernel ridge regression for excited states dynamics of CH2NH$_2^ From single state to multi state representations and multi property machine learning models
venue: Mach. Learn. Sci. Technol.
year: 2020

abstract: Along with the possibilities of lighter and stronger materials, clean water and sustainable energy, the development of nanomedicine is one of the primary reasons why huge amounts of public funding are currently going into the development of nanotechnology worldwide. The environmental risks of conventional medical products did not receive much attention until the 1990s; however, the potential environmental side effects have come under increased scientific and regulatory scrutiny in the last decade. In this Editorial, we will take a closer look at scientific and regulatory issues related to the environmental risks of nanomedical products and we will discuss some of the challenges that need to be addressed to ensure that nanomedicines are not only safe for humans but also for the environment. Although the field of nanotechnology is very broad in scope, most attention with regard to human health and environmental risks has evolved around engineered nanoparticles (ENPs) such as C60, carbon nanotubes, metals, metaloxides and quantum dots [1] At the same time, potential risks related to dendrimers and liposomes have only been raised to a lesser extent. The application of ENPs for medical use offers immense benefits within areas, such as diagnosis, targeted drug delivery and drug development [101] However, the use of ENPs in nanomedicine has not been subject to much regulatory scrutiny because existing laws and regulatory instruments are believed to also cover medical products based on nanotechnology. The extensive testing requirements prior to marketing of medicine may also contribute to the notion that the potentially negative effects will be discovered prior to marketing, that patients are adequately informed about negative side effects and that the benefits outweigh the risks or the adverse effects, should such be found to occur.
author_names: Anders Baun

Steffen Foss Hansen
title: Environmental challenges for nanomedicine.
venue: Nanomedicine
year: 2008

abstract: Von Neumann, the inventor of the modern computer, realized that if life is a physical process, it should be possible to implement life in other media than biochemistry. In the 1950s, he was one of the first to propose the possibility of implementing genuine living processes in computers and robots. This perspective, while still controversial, is rapidly gaining momentum in many science and engineering communities. Below, we summarize our recent activities to create artificial life from scratch in physicochemical systems. We also outline the nature of the grand science and engineering challenges faced as we seek to realize Von Neumann's vision: Integration of information processing and material production from the nano to the macroscale in technical systems.
author_names: Steen Rasmussen

Anders Albertsen

Harold Fellermann

Pernille Lykke Pedersen

Carsten Svaneborg

Hans-Joachim Ziock
title: Assembling living materials and engineering life like technologies
venue: GECCO '11
year: 2011

abstract: Ecotoxicity data is a requirement for pre and post market registration of chemicals by European and international regulations (e.g. REACH) The algal toxicity test is frequently used in regulatory risk assessment of chemicals. In order to achieve high reliability and reproducibility the development of standardized guidelines is vital. For algal toxicity testing, the guidelines require stable and uniform conditions of parameters such as pH, temperature, carbon dioxide levels and light intensity. Nanomaterials and other so called difficult substances can interfere with light causing a large variation in results obtained hampering their regulatory acceptance. To address these challenges, we have developed LEVITATT (LED Vertical Illumination Table for Algal Toxicity Tests) The setup utilizes LED illumination from below allowing for a homogenous light distribution and temperature control while also minimizing intra sample shading. The setup optimizes the sample volume for biomass quantification and does at the same time ensure a sufficient influx of CO2 to support exponential growth of the algae. Additionally, the material of the test containers can be tailored to minimize adsorption and volatilization. When testing colored substances or particle suspensions, the use of LED lights also allows for increasing the light intensity without additional heat generation. The compact design and minimal equipment requirements increase the possibilities for implementation of the LEVITATT in a wide range of laboratories. While compliant with standardized ISO and OECD guidelines for algal toxicity testing, LEVITATT also showed a lower inter sample variability for two reference substances (3,5 Dicholorophenol and K2Cr2O7) and three nanomaterials (ZnO, CeO2, and BaSO4) compared to Erlenmeyer flasks and microtiter plates.
author_names: Lars M Skjolding

Susanne Kruse

Sara Norgaard Sorensen

Rune Hjorth

Anders Baun
title: A Small Scale Setup for Algal Toxicity Testing of Nanomaterials and Other Difficult Substances.
venue: Journal of visualized experiments JoVE
year: 2020