Search

An isoporous membrane with strictly controlled pore size, shape and distribution could provide an efficient, precise and mild sieving of particles in nanotechnology and biomedical applications. However there is a lack of highly porous polymeric membranes combining isoporosity and high permeance in the range below 500 nm. Track-etched membranes are practically the only commercial option. Membranes prepared by phase inversion typically have a broad pore size distribution. Most nanofabrication methods have limited the preparation of membranes with pores in the micrometer range. In this work, we present a nanotechnology-based fabrication methodology to manufacture a stable and flexible nanoporous polymeric membrane with 300 nm isopores using UV nanoimprint lithography. The highly porous membrane has a pore density of 4 × 10

The prompt appearance of multiantibiotic-resistant bacteria necessitates finding alternative treatments that can attenuate bacterial infections while minimizing the rate of antibiotic resistance development.

Understanding climate change impacts on the Cape Floristic Region requires improved knowledge of plant physiological responses to the environment. Studies examining physiological responses of mountain fynbos have consisted of campaign-based measurements, capturing snapshots of plant water relations and photosynthesis. We examine conclusions drawn from prior studies by tracking in situ physiological responses of three species, representing dominant growth forms (proteoid, ericoid, restioid), over 2 years using miniature continuous sap flow technology, long-term observations of leaf/culm water potential and gas exchange, and xylem vulnerability to embolism. We observed considerable inter-specific variation in the timing and extent of seasonal declines in productivity. Shallow-rooted Erica monsoniana exhibited steep within-season declines in sap flow and water potentials, and pronounced inter-annual variability in total daily sap flux (Js). Protea repens showed steady reductions in Js across both years, despite deeper roots and less negative water potentials. Cannomois congesta—a shallow-rooted restioid—was least negatively impacted. Following rehydrating rain at the end of summer, gas exchange recovery was lower in the drier year compared with the normal year, but did not differ between species. Loss of function in the drier year was partially accounted for by loss of xylem transport capacity in Erica and Cannomois, but not Protea. Hitherto unseen water use patterns, including inter-annual variability of gas exchange associated with contrasting water uptake properties, reveal that species use different mechanisms to cope with summer dry periods. Revealing physiological responses of key growth forms enhances predictions of plant function within mountain fynbos under future conditions.

Kimberley was established in 1871 when the first diamond was found in the Kimberley region and then in 2013, the construction of Sol Plaatje University started, and in 2014, they enrolled their first students. Therefore, this study will determine the impact of studentification on Kimberley’s sustainable planning and development. Studentification can be defined as transforming the university’s surrounding neighbourhoods with the influx of students and university staff. Studentification refers to the increase in the number of students in the university areas, as these increases impact the socio-economic and physical aspects of the urban space. Thus, this study will focus on the physical infrastructure and land uses and determine the impact of studentification on Kimberley’s urban social spaces and economic and environmental aspects. The study will also categorise different student housing needs and address these student accommodation needs. This research will adopt a non-experimental approach, which will adopt a qualitative methodology consisting of interviews with specific individuals as a purposeful selection of these individuals who have a good understanding of the research and will be seen as an asset to the study. Nevertheless, the data will be collected through multiple sources and divided into primary and secondary data collection. The primary collection of data will consist of the interview process of 17 specific individuals, and the secondary collection of data will focus on pre-existing data as reviewing of literature and policies and analysing statistics of Kimberley. This is just a brief understanding of the methodology of the study. As part of the secondary data collection, section 2 illustrates the existing literature on studentification reflection on sustainable planning and development and student housing. Reviewing these aspects will provide a broad understanding of the topics relevant to the study. Then, section 3 will review the existing national and provincial legislation, strategies, plans and programmes that govern studentification and student accommodation in South Africa. Reviewing these processes will focus on determining the effects of studentification on Kimberley’s current land uses, infrastructure, Local Economic Development, property values, and the various housing needs of students and how these can be accommodated. The empirical investigation will be divided into two sections to determine the impact of studentification on Kimberley's sustainable planning and development. Analysed the primary data collected through interviews with professional planners, SPU Senior Manager and Student Support and Physical Planning and Infrastructure Director, and residents in surrounding neighbourhoods. These personal interview questions will be formulated to answer the three research questions of the study. Nevertheless, analysing these interviews, they have identified challenges and recommendations for studentification in Kimberley. Then, with the identified challenges and recommendations, two proposals will be formulated, planning policy frameworks and innovations for off-campus student housing. These two proposals would positively affect Kimberley's studentification and promote off-campus student accommodation. &nbsp

Polymers have been used effectively in the Oil & Gas Industry for a variety of field applications, such as enhanced oil recovery (EOR), well conformance, mobility control, and others. Polymer intermolecular interactions with the porous rock, in particular, formation clogging and the associated alterations to permeability, is a common problem in the industry. In this work, fluorescent polymers and single-molecule imaging are presented for the first time to assess the dynamic interaction and transport behavior of polymer molecules utilizing a microfluidic device. Pore-scale simulations are performed to replicate the experimental observations. The microfluidic chip, also known as a "Reservoir-on-a-Chip" functions as a 2D surrogate to evaluate the flow processes that take place at the pore-scale. The pore-throat sizes of an oil-bearing reservoir rock, which range from 2 to 10 nm, are taken into consideration while designing the microfluidic chip. Using soft lithography, we created the micromodel from polydimethylsiloxane (PDMS). The conventional use of tracers to monitor polymers has a restriction due to the tendency of polymer and tracer molecules to segregate. For the first time, we develop a novel microscopy method to observe the dynamic behavior of polymer pore-clogging and unclogging processes. We provide direct dynamic observations of polymer molecules during their transport within the aqueous phase and their clustering and accumulations. Pore-scale simulations were carried out to simulate the phenomena using a finite-element simulation tool. The simulations revealed a decline in flow conductivity over time within the flow channels that experienced polymer accumulation and retention, which is consistent with the experimental observation of polymer retention. The performed single-phase flow simulations allowed us to assess the flow behavior of the tagged polymer molecules within the aqueous phase. Additionally, both experimental observation and numerical simulations are used to evaluate the retention mechanisms that emerge during flow and how they affect apparent permeability. This work provides new insights to assessing the mechanisms of polymer retention in porous media.

Liquid hydrogen (LH2) storage is viewed as a viable approach to assure sufficient hydrogen capacity at commercial fuelling stations. Presently, LH2 is produced at remote facilities and then transported to the end-use site by road vehicles (i.e., LH2 tanker trucks). Venting of hydrogen to depressurize the transport storage tank is a routine part of the LH2 delivery and site transfer process. The behavior of cold hydrogen plumes has not been well characterized because of the sparsity of empirical field data, which can lead to overly conservative safety requirements. Committee members of the National Fire Protection Association (NFPA) Standard 2 [1] formed the Hydrogen Storage Safety Task Group, which consists of hydrogen producers, safety experts, and computational fluid dynamics modellers, has identified the lack of understanding of hydrogen dispersion during LH2 venting of storage vessels as a critical gap for establishing safety distances at LH2 facilities, especially commercial hydrogen fuelling stations. To address this need, the National Renewable Energy Laboratory Sensor Laboratory, in collaboration with the NFPA Hydrogen Storage Task Group, developed a prototype Cold Hydrogen Plume Analyzer to empirically characterize the hydrogen plume formed during LH2 storage tank venting. The prototype analyzer was field deployed during an actual LH2 venting process. Critical findings included: • Hydrogen above the lower flammable limit (LFL) was detected as much as 2 m lower than the release point, which is not predicted by existing models. • Personal monitors detected hydrogen at ground level, although at levels below the LFL. • A small but inconsistent correlation was found between oxygen depletion and the hydrogen concentration. • A negligible to non-existent correlation was found between in-situ temperature measurements and the hydrogen concentration. The prototype analyzer is being upgraded for enhanced metrological capabilities, including improved real-time spatial and temporal profiling of hydrogen plumes and tracking of prevailing weather conditions. Additional deployments are planned to monitor plume behavior under different wind, humidity, and temperature conditions. The data will be shared with the Hydrogen Storage Task Group and ultimately will be used support theoretical models and code requirements prescribed in NFPA 2.

The use of hydrogen as a clean and renewable energy source is increasing rapidly for both vehicle and stationary applications. There are safety concerns for the locations in which hydrogen is made, used, and transported (i.e., pipelines and tanker trucks). Sensors are needed to comply with safety regulations and to enable a smooth and safe rollout of hydrogen as an alternative energy. However, hydrogen sensors do not yet exist that have the combined features of small size and low power for easy deployment coupled with high-volume manufacturability and low cost. This is necessary to accommodate the emerging fixed and mobile markets while retaining critical metrological metrics, including measurement range, detection limits, selectivity, fast response, stability, and long lifetime. An amperometric gas sensor for hydrogen (AGS) has been developed using an innovative manufacturing method. The sensor was designed using scalable fabrication strategies based on “Printed Electronics” (PE) methodology which are compatible with large-scale production. Prototype sensors were batch fabricated with multiple individual elements on a substrate compatible in size with a standard 8-inch wafer to enable high-volume, low-cost manufacturing, thereby leveraging PE and semiconductor fabrication infrastructure. This novel AGS was instrumented with control circuitry and evaluated for hydrogen detection in the range of 0–5000 ppmv H2 in air. Specific performance evaluations included assessment of the sensor measurement range, repeatability, and selectivity.

O livro “Inovações e tendências no ensino e pesquisa em conforto ambiental e sustentabilidade do ambiente construído” apresenta uma seleção de artigos apresentados no VI Enanparq, ocorrido em 2021, durante a pandemia de Covid-19. As contribuições trazidas por esse livro demonstram que teorias para o ensino de projeto arquitetônico e conforto ambiental ainda estão sendo discutidas e formuladas e que muitos experimentos vêm sendo desenvolvidos, na busca de melhores práticas. No âmbito da pesquisa e formação em conforto ambiental e arquitetura sustentável, destaca-se um ambiente variável, ambíguo e complexo, que demanda novas perspectivas para o ensino em cursos de Arquitetura e Urbanismo. Nesse contexto, faz-se destaque à pedagogia intitulada blended learning, ou aprendizagem híbrida, método que une elementos do ensino online e presencial, muito explorado durante a pandemia. Faz-se destaque também à sala de aula invertida, em que o estudante deve assistir a palestras e ler textos disponibilizados antes das aulas práticas, de forma a aumentar o tempo em sala de aula para a aplicação prática dos conceitos aprendidos. Os resultados dessas novas pedagogias para o ensino de projeto arquitetônico e conforto ambiental ainda não se demonstraram, no entanto, inteiramente positivos, sendo a discussão de estudos de caso bastante válida. Vale ressaltar, nesse sentido, que a tradição do ateliê para o ensino de projeto arquitetônico não se demostra facilmente adaptável ao ensino à distância, tendo em vista o princípio da conversa reflexiva entre estudante e instrutor.

Motion sensors are an essential component of many electronic systems. However, the development of inertial motion sensors based on fatigue-free soft proof mass has not been explored extensively in the field of soft electronics. Nontoxic gallium-based liquid metals are an emerging class of material that exhibit attractive electromechanical properties, making them excellent proof mass materials for inertial sensors. Here, we propose and demonstrate a fully soft laser-induced graphene (LIG) and liquid metal-based inertial sensor integrated with temperature, humidity, and breathing sensors. The inertial sensor design confines a graphene-coated liquid metal droplet inside a fluidic channel, rolling over LIG resistive electrode. The proposed sensor architecture and material realize a highly mobile proof mass and a vibrational space for its oscillation. The inertial sensor exhibits a high sensitivity of 6.52% m

The pleural lobes are the origin of different pathologies, including malignant tumors, e.g., pleural mesothelioma. In some cases, clinical and macroscopic presentation point strongly to the diagnosis but often enough the patient has another underlying disease; malignant neoplasms of the lung as well as other organs (skin, pancreas, prostate or kidney) can mimic pleural mesothelioma and if so, are defined as ‘pseudo-mesothelioma’. We present eight cases that are clinically and macroscopically highly suspicious for pleural mesothelioma. All patients were autopsied due to medico-legal issues and work-related diseases. Six out of eight patients underwent autopsy to exclude possibility of asbestos-related malignancy and two out of eight due to exclusion of silicosis. From the eight cases, only three were real pleural mesotheliomas. Another three were adenocarcinomas of the lung mimicking pleural mesotheliomas. One had squamous cell carcinoma of the lung. Lastly, one patient had an extraordinary case of papillary renal cell carcinoma metastasizing universally in both pleura lobes. Due to striking morphological similarities, the exact final diagnosis was only possible after extended immunohistochemical analysis of the tissues. In summary, not only is it difficult to distinguish between real or pseudo pleural mesothelioma in patients having had contact with asbestos. Even patients with no evidence of asbestos contact can have clinical and pathological events strongly suggesting asbestosis and mesothelioma, without having it.