UV protection of polyamide fabrics with polymeric nanocomposites

Sun protective textiles are highly important regarding health problems, not only for children, but also for people who spend a lot of time outdoors in their line of work. The present study shows results for UV protection with thin and thick polyamide textile fabrics treated with different polymeric nanocomposites. Tests with different concentrations of ZnO, Al2O3, SiO2 and TiO2 nanoparticles, dispersed in PMMA, were performed. A more effective UV protection is achieved for TiO2 and ZnO nanocomposites. The increase in UV protection functionality is generally higher for higher concentration of nanoparticles in PMMA matrix and for thicker fabrics. UV protection is eventually more uniform and also more resistant to washing in DBD treated fabrics. Durability of UV protection with ZnO-PMMA stands up to ten washing cycles becoming less effective for more than ten washing cycles. Durability of UV protection given by TiO2, SiO2 and Al2O3 in PMMA is good facing abrasion and washing conditions

The effect of direct thermal method, temperature and time on microstructure of a cast aluminum alloy

The direct thermal method is used for the creation of globular microstructures suitable for semi-solid metal forming. In this paper both simulation and experimental results using direct thermal method are presented. ProCAST® software was used to estimate temperature distribution inside the aluminium billet. In validation work, molten aluminium A356 was poured into metallic copper tube moulds and cooled down to the semi-solid temperature before being quenched in water at room temperature. The effect of pouring temperatures of 630°C, 650°C, 665°C, 680°C and holding times of 45s and 60s on the microstructure of aluminium A356 alloy were investigated. The simulation results showed that the average temperature rate within the copper mould, from initial pouring temperature to just before quenching, was approximately 1°C/s. Examination of the solidified microstructures showed that the microstructure was more spherical when lower pouring temperatures and holding periods were used. From the micrographs it was found that the most globular and smallest structures were achieved at processing parameters of 630°C and 45s

Acclimatization of the Growth of Brassica Juncea to Temperature Stress: Future of IoT Technology in Sustainable Agriculture

Agriculture and global warming are correlated with each other, particularly, it may affect nutrient cycles, microbial activities, and physiological activities of the crops. Agricultural development plays a crucial role in the growth of the economy of developing countries. The agriculture sector is a major source of employment in most of the developing countries. Over the year, there were changes and productivity loss due to the abiotic stresses and imbalance of nutrients of the plants. A continuous increase in temperature may affect the yields of crops up to 17%. Each plant has different characteristics in growth and some plants are susceptible to high temperature, some are quite the opposite. A Brassica Juncea L. belongs to a mustard family Brassicaceae or Cruciferae that are susceptible to high temperature. So, in this work, an attempt has been made for Brassica Juncea L. to grow and yield under temperature stress by controlling the temperature with the use of the Internet of Things (IoT). The experiment has been conducted where Brassica Juncea neither production nor consumption. IoT sensors are used to monitor the temperature and humidity in two different scenarios. This paper analyses the factors that affect the growth of Brassica Juncea and provide a solution to increase productivity. View Article DOI: 10.47856/ijaast.2022.v09i04.00

Durable functionalities in polyamide 6.6 with ZnO-PMMA nanocomposites

Hydrophobicity and hydrophility functionalities imparted in polyamide 6.6 fabrics were tested aiming their permanency facing conditions of wearable common use as domestic washing. High improvement in functional behavior is obtained for well dispersed ZnO nanoparticles in a polymeric matrix applied in polyamide 6.6 fabrics. UV protection has been assigned as very effective for the PA fabric finished with ZnO-PMMA nanocomposite. Experiments were carried out in the fabrics treated with optimized ZnO-PMMA nanocomposites being washing durability of these nanocomposites in PA 6.6 fabrics evaluated measuring hydrophobic behavior by the static water contact angle. Washing durability of hydrophility has been tested when the plasmatic preparation of textile polyamide substrates was made. Surface modification of PA 6.6 with plasma treatment has been evaluated by SEM, AFM and XPS techniques, demonstrating oxidative changes and creation of roughness

Relationship between casting modulus and grain size in cast A356 aluminium alloys

Microstructure of Al-Si alloy castings depends most generally on melt preparation and on the cooling rate imposed by the thermal modulus of the component. In the case of Al-Si alloys, emphasis is put during melt preparation on refinement of pro-eutectic (Al) grains and on modification of the Al-Si eutectic. Thermal analysis has been used since long to check melt preparation before casting, i.e. by analysis of the cooling curve during solidification of a sample cast in an instrumented cup. The conclusions drawn from such analysis are however valid for the particular cooling conditions of the cups. It thus appeared of interest to investigate how these conclusions could extrapolate to predict microstructure in complicated cast parts showing local changes in the solidification conditions. For that purpose, thermal analysis cups and instrumented sand and die castings with different thermal moduli and thus cooling rates have been made, and the whole set of cooling curves thus recorded has been analysed. A statistical analysis of the characteristic features of the cooling curves related to grain refinement in sand and die castings allowed determining the most significant parameters and expressing the cube of grain size as a polynomial of these parameters. After introduction of a further parameter quantifying melt refining an excellent correlation, with a R2 factor of 0.99 was obtained

Fabrication of Nd3+ and Yb3+ doped NIR emitting nano fluorescent probe: A candidate for bioimaging applications

The intentional design of rare earth doped luminescent architecture exhibits unique optical properties and it can be considered as a promising and potential probe for optical imaging applications. Calcium fluoride (CaF2) nanoparticles doped with optimum concentration of Nd3+ and Yb3+ as sensitizer and activator, respectively, were synthesized by wet precipitation method and characterized by x-ray diffraction (XRD) and photoluminescence. In spite of the fact that the energy transfer takes place from Nd3+ to Yb3+, the luminescence intensity was found to be weak due to the lattice defects generated from the doping of trivalent cations (Nd3+ and Yb3+) for divalent host cations (Ca2+). These defect centres were tailored via charge compensation approach by co-doping Na+ ion and by optimizing its concentration and heat treatment duration. CaF2 doped with 5 mol% Nd3+, 3 mol% Yb3+ and 4 mol% Na+ after heat treatment for 2 h exhibited significantly enhanced emission intensity and life time. The ex vivo fluorescence imaging experiment was done at various thickness of chicken breast tissue. The maximum theoretical depth penetration of the NIR light was calculated and the value is 14 mm. The fabricated phosphor can serve as contrast agent for deep tissue near infrared (NIR) light imaging

Solidification behavior of intensively sheared hypoeutectic Al-Si alloy liquid

The official published version of this article can be found at the link below.The effect of the processing temperature on the microstructural and mechanical properties of Al-Si (hypoeutectic) alloy solidified from intensively sheared liquid metal has been investigated systematically. Intensive shearing gives a significant refinement in grain size and intermetallic particle size. It also is observed that the morphology of intermetallics, defect bands, and microscopic defects in high-pressure die cast components are affected by intensive shearing the liquid metal. We attempt to discuss the possible mechanism for these effects.Funded by the EPSRC

SmedGD: the Schmidtea mediterranea genome database

The planarian Schmidtea mediterranea is rapidly emerging as a model organism for the study of regeneration, tissue homeostasis and stem cell biology. The recent sequencing, assembly and annotation of its genome are expected to further buoy the biomedical importance of this organism. In order to make the extensive data associated with the genome sequence accessible to the biomedical and planarian communities, we have created the Schmidtea mediterranea Genome Database (SmedGD). SmedGD integrates in a single web-accessible portal all available data associated with the planarian genome, including predicted and annotated genes, ESTs, protein homologies, gene expression patterns and RNAi phenotypes. Moreover, SmedGD was designed using tools provided by the Generic Model Organism Database (GMOD) project, thus making its data structure compatible with other model organism databases. Because of the unique phylogenetic position of planarians, SmedGD (http://smedgd.neuro.utah.edu) will prove useful not only to the planarian research community, but also to those engaged in developmental and evolutionary biology, comparative genomics, stem cell research and regeneration