Investigation of process parameters assessment via Design of Experiments for CO2 photoreduction in two photoreactors

CO2 photoreduction with water to obtain solar fuels is one of the most innovative and sustainable processes to harvest light energy and convert it into hydrocarbons. Although photocatalytically active materials and photoreactors have been developed for this purpose, lack of standardisation in testing conditions makes the assessment of process parameters and the comparison of material performance a challenge. Therefore, this paper is aimed at investigating the effect of CO2 photoreduction parameters irradiance and reaction time on production of methane from two photocatalytic rigs. This was pursued through a design of experiments (DOE) approach, which assessed the influence of experimental conditions between different setups. Using low irradiance (40-60 W m-2), reaction time and temperature significantly affected methane production, with a maximum production of 28.50 μmol gcat-1 (40 W m-2, 4 h). When using high irradiance (60-2400 W m-2), only irradiance was found to significantly affect methane production, with a maximum production of 1.90 ∙ 10-1 μmol gcat-1 (1240 W m-2, 2 h). Considering proposed reaction mechanism for CO2 photoreduction, this paper highlights that experimental results give different yet complementary information on the two most important steps of the process, i.e. photoexcitation and surface chemical reaction

Simulated marine plastics pollution weathering : a novel laboratory system for weathering plastics

Over the last three years there has been a call for more environmentally relevant laboratory weathering experiments. These experiments would require well-defined reaction conditions and standardised reporting of both the rate of degradation and methods used. Several new designs have been proposed, however, no design has yet been developed that meets these requirements. This thesis critically reviews the current plastic weathering methodologies and presents a novel method that produces well-defined conditions, omitted by other works. The method presented here aims to implement irradiance of ultraviolet radiation (UVR), temperature and saltwater parameters in a standardised way, as the three most influential variables of marine plastic weathering. In doing so, the practice of reporting single irradiance values is questioned due to its shortfall when comparing studies. The performance of the proposed method was assessed by weathering five plastics for 18 days before the experiment was stopped due to the Covid-19 Pandemic. The degradation of the plastics was measured using a trio of FTIR interfaces (ATR, Diffuse and Specular). A novel introduction of saltwater to the plastic samples provides stable simulated marine conditions to replicate marine weathering. The weathering characteristics from this method were found to be similar to those reported in outdoor weathering studies, showing that the laboratory method presented here is able to simulate environmental weathering. Despite promising results, the performance of the system could still be improved. The ultraviolet irradiance spectrum produced by the weather-o-meter, failed to match solar irradiance over the UVR range from 310 nm – 350 nm, despite having an overall irradiance which matched solar levels. Given the wavelength specific nature of plastic degradation, future work should aim to report the spectrum used, alongside the total irradiance

The development of a photovoltaic remotely operated laboratory experiment: a contribution to meeting the challenge of the renewable energy skills shortage

Skills shortages are often quoted as a threat to renewables growth. The increasing deployment of photovoltaic (PV) systems around the world requires large numbers of trained engineers with a greater understanding of all aspects of PV technology both theoretical and practical. The development of experimental rigs at universities and training establishments is expensive and limited to students physically being present for time constrained activities. One recent approach to increase access to laboratories is the development of remote experiments. Here students can control real experimental equipment using a graphical user interface via the Internet. In this paper we explore the development of a PV laboratory that characterises PV panels under different environmental conditions. It enables users to access and remotely control experimental equipment based at Loughborough University, UK, from anywhere in the world via an Internet connection. We report on student experiences using the laboratory from distance

Educating the world: a remote experiment in photovoltaics

The increasing deployment of photovoltaic (PV) systems requires large numbers of skilled engineers with a greater understanding of all aspects of PV teehnology both theoretical and practical. Developing experimental rigs at universities is expensive and limited to students physically attending the university. One recent approach to increase access to laboratories is the development of remote experiments. Here students can control real experimental equipment using a visual interface via the Internet. In this paper we explore the development of a photovoltaic laboratory to enable users to access and remotely control experimental equipment based at Loughborough University, UK, from anywhere in the world

The development of a remote laboratory for distance learning and its impact on student learning

Currently, there is an increase drive in the development of remote laboratories to compliment and sometimes replace physical and virtual laboratories. This drive is fuelled by the impact on the pedagogy of distance learning caused by the rapid advancements in information and communication technologies, especially the internet. In this paper we outline the systematic approach used in the development of the Photovoltaic Remote Laboratory at Loughborough University, highlighting challenges and successes. We also evaluate the impact the remote lab has on student learning to contribute to the growing debat

EgoFace: Egocentric Face Performance Capture and Videorealistic Reenactment

Face performance capture and reenactment techniques use multiple cameras and sensors, positioned at a distance from the face or mounted on heavy wearable devices. This limits their applications in mobile and outdoor environments. We present EgoFace, a radically new lightweight setup for face performance capture and front-view videorealistic reenactment using a single egocentric RGB camera. Our lightweight setup allows operations in uncontrolled environments, and lends itself to telepresence applications such as video-conferencing from dynamic environments. The input image is projected into a low dimensional latent space of the facial expression parameters. Through careful adversarial training of the parameter-space synthetic rendering, a videorealistic animation is produced. Our problem is challenging as the human visual system is sensitive to the smallest face irregularities that could occur in the final results. This sensitivity is even stronger for video results. Our solution is trained in a pre-processing stage, through a supervised manner without manual annotations. EgoFace captures a wide variety of facial expressions, including mouth movements and asymmetrical expressions. It works under varying illuminations, background, movements, handles people from different ethnicities and can operate in real time

Feasibility study for the advanced one-dimensional high temperature optical strain measurement system, phase 3

The Instrumentation and Control Technology Division is developing optical strain measurement systems for applications using high temperature wire and fiber specimens. This feasibility study has determined that stable optical signals can be obtained from specimens at temperatures beyond 2,400 C. A system using an area array sensor is proposed to alleviate off-axis decorrelation arising from rigid body motions. A digital signal processor (DSP) is recommended to perform speckle correlations at a rate near the data acquisition rate. Design parameters are discussed, and fundamental limits on the speckle shift strain measurement technique are defined

In a squeeze: Epibiosis may affect the distribution of kelp forests

The processes limiting the population recovery of the kelp Saccharina latissima after recent large‐scale loss from the south coast of Norway are poorly understood. Previous investigations do, however, suggest that the impacts of biotic interactions (epibiosis and competition) and increased water turbidity are important. We investigated the depth‐related patterns of growth, epibiosis, and mortality in two sample populations of kelp, from the south and the southwest coast of Norway. The investigations were performed over a period of seven months, in a crossed translocational study, where kelps were mounted on rigs at six depths (1, 3, 6, 9, 15, and 24 m). In a second experiment, the amounts of light blocked by different epibiont layers growing on the kelp frond were investigated. While growth decreased with depth in spring and summer, the kelp grew faster at 15 m than at shallower depths in fall. Survival was low both in shallow water and below 15 m depth. Epibionts covered the kelp growing at depths from 1 to 9 m, and the laboratory study showed that the coverage may have deprived the individuals of as much as 90% of the available light. Although the depth‐related results we present apply—in the strictest sense—only to kelp translocated on rigs, we argue that the relative patterns are relevant for natural populations. Growth and survival of S. latissima is likely to be reduced by heavy loads of epibionts, while depths where epibionts are sparse may be close to the lower limit of the kelps depth distribution along the south coast of Norway. This suggests that a vertical squeeze, or narrowing of the distribution range of kelp forests may be occurring in Norway.publishedVersio

The development of a remote laboratory for distance learning at Loughborough University

The increasing deployment of photovoltaic systems requires large numbers of skilled engineers with a greater understanding of all aspects of PV technology both theoretical and practical. Developing experimental rigs at universities is expensive and limited to students physically attending the university. One recent approach to increase access to laboratories is the development of remote experiments. Here students can control real experimental equipment using a visual interface via the Internet. In this paper we explore the development of a photovoltaic laboratory to enable users to access and remotely control experimental equipment based at Loughborough University from anywhere in the world