Metal-organic framework (MOF) dispersion based fluids for solar-thermal energy conversion

This paper discusses the potential use of metal–organic framework (MOF) dispersion based fluids for solar-to-thermal energy conversion (STEC). For this, the optical and thermal characteristics of MOF dispersion were investigated, with MOFs dispersed in ethylene glycol (EG). This study is focused on three different MOF dispersions, namely ZIF8/EG, CuBTC/EG, and FeBTC/EG, each with varying concentrations of MOF particles. The results showed that FeBTC/EG at a concentration of 0.3 wt% is the optimal fluid for STEC, exhibiting the highest absorption and STEC efficiency compared to the other two fluids. The study also highlights the trade-off between STEC efficiency and cost, as increasing the concentration of MOF particles decreases the specific absorption rate (SAR). Additionally, the paper evaluates the dispersion stability of FeBTC/EG over time, which is critical for practical STEC applications. The novelty of the paper lies in the use of MOF dispersion based fluids for STEC application, which has not been extensively studied before. This study provides valuable insights into the potential use of MOF/EG for STEC and highlights the importance of optimizing the concentration of MOF particles for efficient and cost-effective performance. This study also introduces the novel application of MOF dispersion based fluids for enhanced STEC performance, showcasing FeBTC/EG as a standout for its high efficiency and stability. It marks a significant stride in utilizing MOF materials for sustainable energy, emphasizing practical considerations of dispersion stability and cost-effectiveness in STEC systems.</p

A Single‐Step Process to Produce Carbon Nanotube‐Zinc Compound Hybrid Materials

An atmospheric‐pressure plasma system is developed and is used to treat carbon nanotube assemblies, producing a hybrid carbon‐zinc structure. This system is integrated into a floating‐catalyst chemical vapor deposition furnace used for the synthesis of macroscopic assemblies of carbon nanotubes to allow for the in‐line, continuous, and single‐step production of nano‐composite materials. Material is deposited from a sacrificial zinc wire in the form of nanoparticles and can coat the surface of the individual carbon nanotubes as they form. Additionally, it is found that the deposited materials penetrate further into the carbon nanotube matrix than a comparable post‐synthesis deposition, improving the uniformity of the material through the thickness. Thus, a single‐step metal‐based coating and carbon nanotube synthesis process which can form the basis of production scale manufacturing of metal‐carbon nanotube composite materials with an atmospheric‐pressure plasma system are demonstrated

A reproducible protocol for regeneration and transformation in canola (Brassica napus L.)

The objective of the present study is to develop an efficient protocol for shoot and plant regeneration using five commercial canola cultivars grown under the Egyptian agricultural conditions. The regeneration efficiency from hypocotyl explants was examined. The data indicated that embryonic calli were formed within two weeks in the presence of 1 mgl-1 2,4-D. Adventitious shoots emerged from the embryonic callus in the presence of 4.5 mgl-1 BA. The cultivars showed a varied response to shoot regeneration. Regeneration frequency was high in the cultivar Sarow-4 (68%) followed by Masrri L-16 (64%) compared with the other cultivars tested. Hypocotyl explants from the cultivars Sarow-4 and Semu-249 were inoculated and co-cultivated with Agrobacterium tumefaciens strain LBA4404 harboring a binary vector pBI-121 containing the neomycin phosphotransferase-II gene (NPT-II). The resulted putative transgenic plantlets were able to grow under knanamycin containing medium. The stable integration of the NPT-II gene into the plant genomes was tested by PCR using NPT-II -specific primers. The GUS gene expression can be detected only in the transgenic plants. The reported protocol in the present study is repeatable and can be used to regenerate transgenic canola plants expressing the genes present in A. tumifaciens binary vectors.Keywords: Agrobacterium, canola, GUS assay, regeneration, fransformation, NPT II gen

Nanofluids for direct-absorption solar collectors—DASCs : a review on recent progress and future perspectives

Owing to their superior optical and thermal properties over conventional fluids, nanofluids represent an innovative approach for use as working fluids in direct-absorption solar collectors for efficient solar-to-thermal energy conversion. The application of nanofluids in direct-absorption solar collectors demands high-performance solar thermal nanofluids that exhibit exceptional physical and chemical stability over long periods and under a variety of operating, fluid dynamics, and temperature conditions. In this review, we discuss recent developments in the field of nanofluids utilized in direct-absorption solar collectors in terms of their preparation techniques, optical behaviours, solar thermal energy conversion performance, as well as their physical and thermal stability, along with the experimental setups and calculation approaches used. We also highlight the challenges associated with the practical implementation of nanofluid-based direct-absorption solar collectors and offer suggestions and an outlook for the future

Plasma-induced non-equilibrium electrochemistry synthesis of nanoparticles for solar thermal energy harvesting

Rapid plasma-induced non-equilibrium electrochemistry (PiNE) at atmospheric pressure was used to prepare surfactant-free gold nanoparticles and copper oxide quantum dots. A suite of chemical and physical characterisation is carried out to assess the as-prepared materials. Nanofluids comprised of these nanoparticles in ethylene glycol have been prepared. The energy absorptive properties of the prepared nanofluids were investigated as a potential additive to the traditional working fluids used in solar thermal collectors. The application feasibility has been assessed by calculating a value of power which could be transferred to the thermal fluid. This work demonstrates an alternative and rapid method to produce nanofluids for solar thermal conversion.EPSR

Metal-organic framework (MOF) dispersion based fluids for solar-thermal energy conversion

This paper discusses the potential use of metal–organic framework (MOF) dispersion based fluids for solar-to-thermal energy conversion (STEC). For this, the optical and thermal characteristics of MOF dispersion were investigated, with MOFs dispersed in ethylene glycol (EG). This study is focused on three different MOF dispersions, namely ZIF8/EG, CuBTC/EG, and FeBTC/EG, each with varying concentrations of MOF particles. The results showed that FeBTC/EG at a concentration of 0.3 wt% is the optimal fluid for STEC, exhibiting the highest absorption and STEC efficiency compared to the other two fluids. The study also highlights the trade-off between STEC efficiency and cost, as increasing the concentration of MOF particles decreases the specific absorption rate (SAR). Additionally, the paper evaluates the dispersion stability of FeBTC/EG over time, which is critical for practical STEC applications. The novelty of the paper lies in the use of MOF dispersion based fluids for STEC application, which has not been extensively studied before. This study provides valuable insights into the potential use of MOF/EG for STEC and highlights the importance of optimizing the concentration of MOF particles for efficient and cost-effective performance. This study also introduces the novel application of MOF dispersion based fluids for enhanced STEC performance, showcasing FeBTC/EG as a standout for its high efficiency and stability. It marks a significant stride in utilizing MOF materials for sustainable energy, emphasizing practical considerations of dispersion stability and cost-effectiveness in STEC systems

A single‐step process to produce carbon nanotube‐zinc compound hybrid materials

An atmospheric-pressure plasma system is developed and is used to treat carbon nanotube assemblies, producing a hybrid carbon-zinc structure. This system is integrated into a floating-catalyst chemical vapor deposition furnace used for the synthesis of macroscopic assemblies of carbon nanotubes to allow for the in-line, continuous, and single-step production of nano-composite materials. Material is deposited from a sacrificial zinc wire in the form of nanoparticles and can coat the surface of the individual carbon nanotubes as they form. Additionally, it is found that the deposited materials penetrate further into the carbon nanotube matrix than a comparable post-synthesis deposition, improving the uniformity of the material through the thickness. Thus, a single-step metal-based coating and carbon nanotube synthesis process which can form the basis of production scale manufacturing of metal-carbon nanotube composite materials with an atmospheric-pressure plasma system are demonstrated

Genotype Dependent Somatic Embryogenesis from Egyptian Rice Mature Zygotic Embryos

Abs tract: Seven agronomically and genetically different rice (Oryza sativa L.) c u lt iv a rs were compared for their capacity for callus induction and plant regene ra t io n from mature zygotic embryos . W hite embryonic calli were formed within three weeks in the pres ence of 3 mgl 2,4,D . T h e s o matic Giza 178 s howed high regeneration fre q u e ncy (39%) followed by Giza 175 (38%) where the cultivar H1 s howed the lowes t record (24%). The data obtained fro m t h e random amplified polymorphic DNA analys is s howed that a total of 45 DNA markers were detected among the s e v e n ric e cultivars of wh ich, 29 bands were polymorphic (64.4%) and can be cons idered as us eful RA PD markers for th e rice cultivars us ed. Based on the data obtained by RA PD analys is , it was pos s ible to dis c riminate between the different genotyp e s u s e d . Sixteen out of the twenty nine polymorphic RAPD markers generated were found to be genotype-specific. Thes e markers can be verified as being RAPD markers ass ociated with the rege n e ra t io n c a pacity in the s even rice genotypes. Genetic s tability in tis s uecultured rice plants was examined by randomly amplified polymorphic DNA (RA PD) an a ly s is . T he genetic s imilarity between the mother and the regenerated plants was hig h fo r Giza 178 (91%) and it w a s 87.5 and 82 for Giza 175 and Sakha 102 respectively. The cultivar Giza 178 proved t o b e a us eful genetic res ource with unique regeneration ability and can be us ed for efficient generation of trans genic rice plants

Efficient solar-thermal energy conversion with surfactant-free Cu-oxide nanofluids

Data Availability: Data will be made available on request.Appendix A. Supplementary material available online at https://www.sciencedirect.com/science/article/pii/S2211285522011909?via%3Dihub#sec0065Copyright © 2022 The Author(s). High-specification nanofluids can potentially enable cost-effective and highly efficient solar-to-thermal energy conversion. However, their implementation is adversely affected by poor absorption spectral range and stability challenges of the nanoparticles. Here we demonstrate the synthesis, full characterization and application of Cu-oxide nanoparticles with high optical absorption and long-term stability over many months. The synthesis method, based on a hybrid plasma-liquid non-equilibrium electrochemical process, ensures a very limited environmental impact as it relies on a solid metal precursor while avoiding the use of additional chemicals such as surfactants and other reducing agents. We further investigate the fundamental links between the nanofluid performance and the material and optical properties and produce a theoretical model to determine the energy conversion efficiency. The results show that nanofluids produced with our Cu-oxide nanoparticles can achieve exceptional solar thermal conversion efficiencies close to ∼90% and can provide a viable solution for an efficient solar thermal conversion technology.EPSRC (award no. EP/M024938/1, EP/V055232/1, EP/R008841/1)