5,100 results on '"Characterisation"'
Search Results
2. Nanoclay composites in electrochemical sensors.
- Author
-
Timakwe, Sapokazi, Ngcobo, Sizwe, Smith, Randall, and Matoetoe, Mangaka
- Subjects
ENVIRONMENTAL monitoring ,CARBON electrodes ,ELECTROCHEMICAL sensors ,CARBON compounds ,EFAVIRENZ - Abstract
Nanoclays are layered structures in the nanoscale range with widespread application due to their unique properties such as swelling, cation exchange capacity, and ease of functionalisation using metals, metal oxides, and organic compounds such as carbon paste, polymers, and other biomolecules that form nanoclay composites. Nanoclay functionalisation with silver (Ag), zinc oxide (ZnO), and bimetallic silver–gold (Ag–Au) using hydrophilic and hydrophobic clays is here evaluated and discussed. The composites' synthesis and morphological, crystallinity, and electroactive properties in comparison with pure nanoclay are also assessed. The layered structure and crystallinity of all these nanoclay composites were slightly changed. The clumped layered structures on the surface of the nanocomposites had dispersed white spots that indicated possible surface modification. The nano-films of the composites' electroactivity were comparatively high, as seen from the increase in current in the cyclic voltammetry characterisation voltammograms and the differential pulse voltammograms of the pharmaceutical detection. Efavirenz, nevirapine, and zidovudine detection was improved by modification of the nanocomposite with human serum albumin (HSA), as shown by the higher current, thus indicating improved conductivity of the composites compared to the pure nanoclays. Applying HAS-modified nanocomposites in the analysis of efavirenz, nevirapine, and zidovudine on a glassy carbon electrode (GCE) showed good linearity and acceptable detection limits comparable to those of previous studies. Therefore, it has potential for application in pharmaceutical quality control and environmental monitoring. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Isolation and characterisation of hemicelluloses from oil palm empty fruit bunches.
- Author
-
Tanimu, Musa Idris, Halid, Muhammad Asnawi bin Abdul, Loh, Soh Kheang, and Bachmann, Robert Thomas
- Abstract
A reliable hemicellulose extraction method from oil palm empty fruit bunches (OPEFB) is required for subsequent investigations into its composition and participation in pyrolysis and anaerobic digestion processes. Previous hemicellulose OPEFB research only looked at yield, purity and functional characteristics. In this study, OPEFB extractives were removed followed by hemicellulose A (HA) and B (HB) isolation and characterisation using Fourier-transform infrared, thermogravimetric and ultimate analysis. Energy dispersive X-ray spectroscopy (EDS) was deployed on the extractive-free OPEFB ash. Ethanol-toluene removed 8.2 ± 0.1 wt% extractives from OPEFB, with ethanol only removing another 1.6 ± 0.1 wt% while water extracted a further 5.4 ± 1.1 wt%. Alkaline extraction of OPEFB with 3 M KOH at 40 °C and subsequent centrifugation yielded 28.6 wt% HA, while 8.0 wt% HB was obtained as a precipitate from the supernatant of HA using 95% ethanol. The empirical formula of commercial xylan, a hemicellulose surrogate, and HA and HB were C
5 H9.5 O4.4 , C5 H9.4 O4.1 and C5 H9.8 O2.9 , respectively. FTIR analysis suggests that xylose and arabinose were the main constituents of xylan, HA and HB. The ash content (AC) of HA and HB was ten times greater than xylan (2.7 wt%). EDS analysis suggests that the high AC of HA and HB is attributed to Ca, Mg and Si which could not be effectively removed during extractives removal. Thermogravimetry identified a common decomposition peak at 219 °C confirming the presence of hemicellulose in the isolated HA and HB. Further research is required to refine the extraction protocol to obtain purer OPEFB hemicellulose. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
4. Advancements in microneedle technology: current status and next-generation innovations.
- Author
-
Kumar, Siddhant and Shukla, Rahul
- Subjects
- *
TRANSDERMAL medication , *THREE-dimensional printing , *ELECTROPORATION , *DERMIS - Abstract
AbstractMicroneedle technology is a pivotal component of third-generation transdermal drug delivery systems featuring tiny needles that create temporary microscopic channels in the stratum corneum which facilitate drug penetration in the dermis. This review offers a detailed examination of the current types of microneedles, including solid, coated, dissolving, hollow, and swelling microneedles, along with their preparation techniques as well as their benefits and challenges. Use of 3D printing technology is especially gaining significant attention due to its ability to achieve the high dimensional accuracy required for precise fabrication. Additionally, its customisability presents significant potential for exploring new designs and creating personalised microneedles products. Furthermore, this review explores next generation microneedles, especially stimuli-responsive microneedle, bioinspired microneedle and microneedles combined with other transdermal technology like sonophoresis, electroporation and iontophoresis. Regulatory aspects, characterisation techniques, safety considerations, and cost factors have also been addressed which are crucial for translation from lab to the market. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Odour characterisation of recycled HDPE in different washing and processing processes.
- Author
-
Martínez, Juan López, Rodríguez Rego, Jesús Manuel, Cerezo, Laura Mendoza, Madrigal, María Dolores Samper, and Macías-García, Antonio
- Subjects
HIGH density polyethylene ,PLASTICS ,CONSUMER goods ,MANUFACTURING processes ,PACKAGING waste - Abstract
The waste of polymeric materials in our society is increasing year after year, generating a serious pollution problem. One way to deal with this waste problem is to recycle and reuse these materials. This process of recovery of used plastic materials aims to minimise their impact on the environment and reduce the energy consumption required for the generation of new consumer products. Recycling companies that recover these plastic materials must take into account some aspects such as transparency and colour, cleanliness, size, odour and sorting. One of the major disadvantages in accepting these recycled materials in the production processes is their odour, which in some cases causes the rejection of materials with comparable mechanical characteristics. High-density polyethylene, HDPE, is one of the polymeric wastes generated in the packaging industry. The aim of this work is to eliminate the bad odour of HDPE from waste collection plants for application in the recovery and reuse industry. HDPE supplied by a recycling company was washed, characterised and processed, and the odour was analysed by gas chromatography at each stage and by olfactory panel. In view of the results, it was observed that the washing processes managed to reduce the odour. Likewise, the processing of this waste by extrusion and injection managed to further reduce this effect, even eliminating some of the components responsible for odour by treating the samples with acetone and then extruding and injecting these samples. These results have a direct application in the packaging industry with significant shares of recycled material. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Development of chitosan nanoparticle loaded with Tricholoma fracticum extract and evaluation of in vitro antioxidant activity.
- Author
-
Canbolat, Fadime, Acar, İsmail, and Tezel, Ruhiye Nilay
- Subjects
- *
FIELD emission electron microscopy , *TRANSMISSION electron microscopy , *GALLIC acid , *ZETA potential , *FLAVONOIDS - Abstract
Summary: The objective of this study was to develop Tricholoma fracticum extract‐loaded chitosan nanoparticles (TFNPs) by ionic gelation method and to evaluate their in vitro antioxidant activity. Phenolic and flavonoid contents in the T. fracticum extract were measured spectrophotometrically and chromatographically. Characterisation of NPs was evaluated by field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), ZETA analysis, Fourier‐transform infrared spectroscopy (FT‐IR), UV–visible spectroscopy (UV–Vis) and thermogravimetric analysis (TGA). In vitro antioxidant capacity was determined using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) assays. The phenolic and flavonoid contents in the T. fracticum extract were measured as 7.1 ± 0.3 mg Gallic Acid Equivalent/g extract and 5.5 ± 0.6 mg Quercetin Equivalent/g extract, respectively. The particle size, polydispersity index (PDI) and zeta potential of Blank NP1 and TFNP were 265.5 ± 15.8 nm, 0.4, 38.7 ± 4.0 mV and 333.2 ± 16.3 nm, 0.4, 37.0 ± 4.1 mV, respectively. The highest antioxidant activity was observed in TFNP, followed by T. fracticum extract, chitosan and blank NP, respectively. The preserved or enhanced antioxidant activity observed in the encapsulated T. fracticum extract indicates the potential for loading similar mushroom extracts onto chitosan and thus preserving their bioactive properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Preliminary Characterisation of Thermal Upgrading of Nickel from Saprolite via Selective Reduction.
- Author
-
Bahfie, Fathan, Manaf, Azwar, Astuti, Widi, Nurjaman, Fajar, Prasetyo, Erik, Susanti, Diah, and Sipahutar, Wahyu Solafide
- Subjects
DIFFERENTIAL thermal analysis ,IRON-nickel alloys ,X-ray fluorescence ,SCANNING electron microscopy ,HEMATITE - Abstract
The mineralogical properties and distribution of information established in saprolite from Indonesia were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy energy dispersion spectroscopy (SEM--EDS) and differential thermal analysis (DTA) measurements. The findings suggest that laterite ore has a complex inner core. The percentages of nickel, iron, magnesium, aluminium and silicon in saprolite are 1.82 wt%, 30.47 wt%, 10--20 wt%, 4.86 wt% and 8.1 wt%. Saprolite has 53.1 wt% iron oxide/oxyhydroxide, 38.3 wt% lizardite and 8.7 wt% silicate. According to DTA, saprolite undergoes a phase shift from goethite to haematite at low temperatures (200--300°C). This is a suitable phase to optimise nickel diffusion in iron. Furthermore, the thermal upgrading approach was utilised for this saprolite. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Synthesis and Characterisation of Cellulose Acetate/Polyethylene Glycol Membrane from Pineapple Hump by Phase Inversion Method.
- Author
-
Yuwono, Suripto Dwi, Suprajaya, Kadek, Nurhasanah, Sangging, Putu Ristyaning Ayu, Kusumawati, Anita, Sukmana, Irza, Nazarudin, Susanti, Diah, Ardiyansyah, Hosta, Suharto, Haryadi, Harta, and Bahfie, Fathan
- Subjects
BIOPOLYMERS ,CELLULOSE synthase ,POLYETHYLENE glycol ,FOURIER analysis ,WAVENUMBER ,CELLULOSE acetate - Abstract
Cellulose is a natural polymer contained in growing fibres, such as pineapple fibres. Cellulose can be modified into cellulose acetate, a modified polymer that can be used in the synthesis of a cellulose acetate/polyethylene glycol (CA/PEG) membrane. The phase inversion method was used in this study to produce CA/PEG membranes. Variations in polyethylene glycol (PEG) concentration with a ratio of 1:1 to cellulose acetate, where variations in PEG concentrations used are 2%, 5% and 8%. Acetone and dimethylformamide are used as organic solvents. Membrane morphological analysis using scanning electron microscopy (SEM) and functional group analysis using a Fourier transform infrared (FTIR) spectrometer were performed for membrane characterisation. The result of the synthesis of the CA/PEG membrane is in the form of a thin white layer. The characterisation results of the FTIR spectrometer showed the vibration of the carbonyl bond at wavenumber 1729 cm--1 and the vibration of the hydroxyl bond torque at the wave number 648 cm--1, where the vibration intensity decreased with each addition to the concentration. The results of SEM characterisation show that the increase in PEG concentration increases the percentage porosity of the membrane. The membranes with 2%, 5% and 8% PEG have porosity percentages of 51.54%, 68.70% and 73.50%, respectively. As the membrane with 2% PEG has the lowest percent porosity, it has more potential in removing or filtering solutes from a fluid. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. A Comprehensive Review of the Multifaceted Characterisation Approaches of Dental Ceramics.
- Author
-
Al-Johani, Hanan, Haider, Julfikar, Satterthwaite, Julian, Borba, Marcia, and Silikas, Nick
- Subjects
MATERIALS testing ,SHEAR (Mechanics) ,DENTAL translucency ,PHOTON absorptiometry ,MECHANICS (Physics) ,COMPUTER-aided design ,COLORIMETRY ,SURFACE properties ,TENSILE strength ,SCANNING electron microscopy ,DENTAL ceramics ,BIODEGRADABLE materials ,CALORIMETRY ,PROSTHESIS design & construction ,RELIABILITY (Personality trait) ,CRYSTALLOGRAPHY ,SPECTROPHOTOMETRY ,FLUORESCENCE spectroscopy - Abstract
Ceramic dental restorative materials have growing popularity, albeit their brittle and stochastic nature are acknowledged shortcomings that impact the prosthesis lifespan. The mechanical performance of ceramics is dominated by the constitutional microstructural and fracture toughness mechanisms, as well as externally applied triggers. Thus, there is ongoing expanding research in the sphere of ceramic material engineering and thermal refinement, addressing concerns regarding toughness, machinability, reliability, stainability, and biodegradation. While the current trend in dental ceramic manufacturing has transitioned from micrometric crystalline sizes to submicrometric and nanometric ranges, there is an unclear understanding of the microstructural implications on ceramic behaviour. Therefore, this review covers the comprehensive characterisation approaches commonly employed in the scientific literature to describe the multifaceted performance aspects as well as clinical-related prerequisites of dental ceramics. Moreover, updated standardised testing parameters and performance thresholds pertaining to ceramic mannerisms are described in an attempt to translate their clinical applicability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Composition of renders and plasters of award-winning buildings in Lisbon (Portugal): A contribution to the knowledge of binders used in the 20th Century.
- Author
-
Almeida, Luís, Silva, A. Santos, Veiga, Rosário, and Mirão, José
- Subjects
PORTLAND cement ,X-ray diffraction ,ANALYTICAL chemistry ,THERMAL analysis ,MICROSCOPY - Abstract
This paper reports on the study of renders and plasters from 20th-century award-winning buildings in Lisbon (Portugal) with the Valmor Prize for Architecture. The mortars have been investigated through XRD, optical and electronic microscopy (SEM-EDS), thermal analysis (TGA/DTA), wet chemical analyses and AAS. The results reveal that the use of air lime lasted until the 1940s. It also highlights the beginning of using of Portland cement in mortars in the 1930s, mixed with air-lime, and the abandonment of mortar formulations solely based on air lime. This study highlights the use of finishing lime-gypsum-based mortars until the 1940s and different types of Portland cement from the 1940s onwards. Portland cement was the main binder for the analysed stone-imitating mortars from 1940s to 1970s. Finally, salt contamination was occasionally found in mortars, which generally reveal a good state of conservation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. The Influence of the Rolling Direction on the Mechanical Properties of the Al-Alloy EN AW-5454-D.
- Author
-
Balant, Matjaž, Vuherer, Tomaž, Majerič, Peter, and Rudolf, Rebeka
- Subjects
FRACTURE mechanics ,STRENGTH of materials ,CRACK propagation (Fracture mechanics) ,BRITTLE fractures ,SCANNING electron microscopes - Abstract
A complementary characterisation of the Al-alloy EN AW-5454 was carried out, intended for obtaining the laser hybrid welding parameters of subassemblies in the automotive industry. The investigation included a microstructural examination and the determination of the alloy's properties using several analytical methods (HV5 hardness measurement, tensile test, Charpy impact toughness, fracture mechanics analysis). Samples were prepared in the longitudinal and transverse directions of a cold-rolled sheet of EN AW-5454 with thicknesses of 3.5 mm and 4 mm. The measured hardness on the thinner sheet was 5% higher than on the thicker sheet. The tensile and yield strength were nominal, while the elongations were smaller by 2.2–3.2% for the longitudinal samples and by 2.7–13.7% for the transverse samples. The smaller deviations from the nominal values are for the thinner sheet metal. A precise topographical analysis showed the brittle fractures of the samples. The Charpy impact toughness results on the thicker plate showed a 20% greater work needed to break it in the longitudinal direction than in the transverse direction. With the thinner sheet metal, 40% greater work was needed. SEM (scanning electron microscope) analysis has shown that the intermetallic Al
6 (Mn,Fe) particles in the longitudinal samples were mostly intact, with evidence of tough areas on the upper part of the fracture, indicating a better toughness than the specimens in the transverse direction. More crushed intermetallic particles were observed at the fractures of the transverse samples, and their distribution appeared to be more oriented in the direction of rolling. Fracture mechanics SENB (single edge notch bending) tests and their analysis showed that the resistance of the material to crack propagation in the longitudinal sample was about 50% greater than that in the transverse sample. SEM analysis of the fractures showed that the state of the intermetallic particles in the fracture mechanics testing and the fracture mechanism differed from the one in the Charpy fractures. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
12. Investigating the Use of Differential Scanning Calorimetry in the Prediction of Part Properties in the High-Speed Sintering Process.
- Author
-
Brown, Ryan, Holden, Alfred, and Majewski, Candice
- Subjects
DIFFERENTIAL scanning calorimetry ,LASER sintering ,TENSILE strength ,TRAVERTINE ,SINTERING - Abstract
High-speed sintering (HSS) is an additive manufacturing (AM) technique with high potential for end-use products. Previous research has identified differential scanning calorimetry (DSC) as being a viable method for evaluating the mechanical performance of parts manufactured using the (similar) laser sintering (LS) process through the determination of the degree of particle melt (DPM). This research expands this to demonstrate the applicability of DPM measurement to the HSS process, demonstrating a clear linear correlation between tensile properties and DPM. The DPM increased from 64.9% to 75.8% as sinter speed was reduced from 180 mm/s to 140 mm/s (a slower speed providing a higher energy input), with the ultimate tensile strength approximately doubling over this range. High coefficients of determination (>0.9) indicate that the DPM is a strong indicator of tensile properties, demonstrating the potential for DPM measurements as quality assessment tools for the HSS process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Experimental investigation on the mechanical performance of the Al2O3 and ZrO2 added Al-Mg-Si alloy for structural applications.
- Author
-
Ogunsanya, Olusegun Adebayo, Adewale Akinwande, Abayomi, Raj Mohan, R, Talabi, Henry, Saravana Kumar, M, Vignesh, M, and Bhowmik, Abhijit
- Abstract
The present-day structural application requires advanced materials at extreme conditions, and the development of it is not economically feasible. As a result, existing material in the composite form has more visibility to suit the purpose. The material's strengths and qualities must be examined before it can be recommended for use in harsh conditions. In the present study, Al
2 O3 (3, 6, 9, 12, and 15 wt.%) and ZrO2 particles (2 wt.%) are reinforced with Al-Mg-Si alloy (Al 6061), which possess good isotropic behaviour and better interface bonding. The double stir casting process was adopted for the hybrid composite development, and the samples were cold rolled to reduce grain size and pores in the composites. The developed composites were subjected to mechanical characterisation tests such as hardness, tensile, compression, impact and flexural tests. An increase in reinforcement percentage enhances the mechanical properties. The improvement was attributed to the high thermal mismatch and reduction in the inter-particle distance by cold rolling and the reinforcements. Scanning electron microscope microstructural examination was conducted, and even dispersion of 3 to 15 wt.% Al2 O3 reinforcements was observed. Tensile elongation decreases with an increase in reinforcement percentage. High elastic modulus and temperature mismatch between matrix and reinforcements increase the strength of the composites. The fracture behaviour of the composites generally showed dimples which are characteristics of ductile fracture, except at 15 wt.% Al2 O3 / 2 wt.% ZrO2 showed a large portion of cleavage planes and grain cracking. The Al-Mg-Si alloy is reinforced with 9 wt%. Al2 O3 / 2 wt.% ZrO2 had the best properties suitable for its use in different structural applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
14. Characterization and Morphometric Identification of Household Fan Dust and its Human Health-Risk Implications.
- Author
-
Ravindra, Khaiwal, Vig, Nitasha, Biswal, Manisha, Sehgal, Rakesh, and Mor, Suman
- Subjects
HEALTH risk assessment ,AIR pollutants ,INDOOR air quality ,BACILLUS megaterium ,AIR pollution ,DUST ,MINERAL dusts - Abstract
Several studies highlight the environmental and human health impacts of outdoor air pollution. However, a significant gap exists in understanding indoor air pollution in urban households. The current work aims to characterize the fan dust samples collected from households in Chandigarh, India. The five composite samples were collected from different areas, including the dining room, drawing room, bedroom, kitchen, and worship room, of different households in the same location. Samples were characterized using various analytical techniques like X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The concentration of all the measured elements was found to be relatively lower when compared with other similar studies. Ca and Fe showed a high household fraction. XRD confirmed the high fraction of calcite and quartz particles in household dust samples. In SEM analysis, circular, irregular flakes and fibrous particles indicated coal combustion particles in the household dust. Additionally, sharp edge particles showed the enrichment of minerals in the dust samples. Health risk assessment results indicated that the hazard index values for children and adult populations were within limits for non-carcinogenic and carcinogenic health risks from three exposure pathways, revealing insignificant health risks. Besides, the microbiological examination identifies Paebacillus barcinonensis and Bacillus megaterium in dining room dust, Bacillus megaterium and Bacillus circulans in dining and drawing room dust, Lysinibacillus boronitolerans in Bedroom dust, Paenibacillus species. and Bacillus species. in worship room dust, Bacillus circulance and Bacillus megaterium in the kitchen area. Human activities were strongly found to be associated with microbial and metal existence in the dust samples. Household dust, contaminated with biological and inorganic pollutants, has the potential to pose health risks to occupants. Hence, the study briefly discusses the approaches to minimize household dust and indoor air pollutants. Therefore, improving indoor air quality should be a vital component of public health protection policies for urban and rural households. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. A Comprehensive Review on the Viscoelastic Parameters Used for Engineering Materials, Including Soft Materials, and the Relationships between Different Damping Parameters.
- Author
-
Koruk, Hasan and Rajagopal, Srinath
- Subjects
- *
VIBRATION tests , *RESONANT vibration , *DIELECTRIC loss , *ATOMIC force microscopy , *DAMPING capacity - Abstract
Although the physical properties of a structure, such as stiffness, can be determined using some statical tests, the identification of damping parameters requires a dynamic test. In general, both theoretical prediction and experimental identification of damping are quite difficult. There are many different techniques available for damping identification, and each method gives a different damping parameter. The dynamic indentation method, rheometry, atomic force microscopy, and resonant vibration tests are commonly used to identify the damping of materials, including soft materials. While the viscous damping ratio, loss factor, complex modulus, and viscosity are quite common to describe the damping of materials, there are also other parameters, such as the specific damping capacity, loss angle, half-power bandwidth, and logarithmic decrement, to describe the damping of various materials. Often, one of these parameters is measured, and the measured parameter needs to be converted into another damping parameter for comparison purposes. In this review, the theoretical derivations of different parameters for the description and quantification of damping and their relationships are presented. The expressions for both high damping and low damping are included and evaluated. This study is considered as the first comprehensive review article presenting the theoretical derivations of a large number of damping parameters and the relationships among many damping parameters, with a quantitative evaluation of accurate and approximate formulas. This paper could be a primary resource for damping research and teaching. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Optimisation and physicochemical characterisation of a thermo-alkali stable laccase produced by wastewater associated Bacillus sp. NU2.
- Author
-
Edoamodu, Chiedu E. and Nwodo, Uchechukwu U.
- Subjects
POLLUTANTS ,CHEMICAL inhibitors ,WHEAT bran ,TRITON X-100 ,ORGANIC solvents ,LACCASE - Abstract
Laccase is a multicopper enzyme that plays a unique role in bioremediation of environmental pollutants. Bacteria were isolated from hospital wastewater and screened for laccase production. The laccase production process condition was optimised, and the laccase obtained was characterised. The 16S rRNA molecular analysis conducted on the best laccase producer revealed a Bacillus sp. NU2 identified. The process conditions: pH5, 45°C, 100 rpm, 5% inoculum, and growth constituents viz: tangerine peel and wheat bran agro-wastes, beef extract, ammonium persulfate, glucose, galactose, xylose, sorbitol, fructose carbon sources; and 4-aminophenol inducer optimally stimulated laccase production. The Bacillus sp. NU2 laccase was optimal at pH and temperature conditions of 8.0°C and 60°C, with a noteworthy pH and thermal stability observed. Furthermore, NU2 laccase showed a moderate/high tolerance and relative activity effect on various chemical inhibitors, halides and surfactant of triton x-100 (105 ± 0.92%), PMSF (107 ± 0.81%), and NaCl (94 ± 0.81%) at 1, 3, and 6 (mM) concentration. Additionally, NU2 laccase maintained a relative activity of 101%, 104%, and 102% for Mg
2+ , Zn2+ , and Fe3+ at 1, 3, and 6 mM respectively. Acetone and propanol significantly upregulated laccase activity at 114 ± 0.0008% and 118.24 ± 0.35 and also at 30 and 20 (%) concentrations. Conclusively, the tolerant effect of Bacillus sp. NU2 laccase in pH, temperature, inhibitors and organic solvents suggests its potential for biotechnological application and promotion of a greener environment. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
17. Identification of Rust Resistance Genes in Wheat (Triticum aestivum L.) Using Molecular Markers and Host–Pathogen Interaction Tests.
- Author
-
Pal, Dharam, Kumar, Subodh, Bhardwaj, Subhash Chander, Gangwar, Om Prakash, Pal, Anjali, Patial, Madhu, Watpade, Santosh, Harikrishna, Mallick, Niharika, Fandade, Vikas, and Roy, J. K.
- Subjects
- *
PUCCINIA graminis , *STRIPE rust , *LEAF rust of wheat , *PUCCINIA striiformis , *WHEAT rusts , *RUST diseases - Abstract
The leaf rust (Puccinia triticina f. sp. tritici), stripe rust (Puccinia striiformis f. sp. tritici), and stem rust (Puccinia graminis f. sp. tritici) are major fungal constraints affecting wheat production worldwide. Identifying and deploying wheat varieties with diverse resistance are the best ways to manage all the rusts. Therefore, a continuous search goes on to identify diverse germplasm with effective rust resistance that expresses at different stages of plant growth (seedling and adult plant). A set of 22 rust resistant wheat genotypes and 4 checks (controls), viz., Avocet‐Yr10, Avocet ‐Yr15, Agra Local, and respective positive checks were studied for characterising rust resistance genes using host–pathogen interactions complemented by molecular markers. Among 22 elite genotypes, 05 genotypes amplified 191 bp fragment with marker PSY1E1, confirmed the presence of gene Lr19/Sr25. These genotypes also expressed resistance to most virulent leaf rust pathotypes, 77‐5 and 77‐9 in host–pathogen interaction test (HPI). Seven genotypes showed the presence of Lr34/Yr18/Sr57/Pm38/Ltn1 in homozygous state, whereas G4 showed its presence in heterozygous condition. Among 22 genotypes, 16 genotypes possessed Yr10. Five genotypes (22.7%) exhibited two gene combinations, Lr19/Sr25, and Yr10 as revealed through the detection of 191 bp fragment with marker PSY1E1 and 260 bp fragment with co‐dominantly inherited microsatellite marker Xpsp3000, respectively. All five genotypes (G2, G3, G8, G9, and G18) also expressed brown glumes controlled by the gene Rg1 tightly linked to Yr10 on the 1BS chromosome. Broad spectrum rust resistance present in these lines in good agronomic backgrounds could be used as potent genetic donors for diverse and durable rust resistance breeding programmes in wheat. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. The quantification of radical concentration in organic radical polymers: techniques and challenges.
- Author
-
Ellingsen, Theo A., Thickett, Stuart C., and Fuller, Rebecca O.
- Subjects
- *
ELECTRON paramagnetic resonance , *RADICALS (Chemistry) , *ORGANIC bases , *INFRARED spectroscopy , *ELEMENTAL analysis , *ELECTRON paramagnetic resonance spectroscopy - Abstract
The development of new high-tech applications based on organic radical polymers has driven significant and renewed focus on these open shell macromolecules. The versatility in synthetic methods makes them highly accessible materials for a variety of researchers from different backgrounds. Although numerous overviews of the synthesis, structure and properties are available, the determination of radical concentration has been largely overlooked. This primer outlines the methods available and the non-trivial nature of the characterisation process. Although quantitative electron paramagnetic resonance and magnetometry are the gold standard for direct measurement of paramagnetism, there also exists a wide range of highly accessible complimentary methods for indirect measure such as ultraviolet–visible spectroscopy, elemental analysis and infrared spectroscopy. Organic radical polymers are being developed for applications such as energy storage, catalysis and spintronics. Quantification of radical content can be nuanced, with a variety of techniques available for characterisation. This primer provides an overview and discusses the challenges of implementation to macromolecules containing pendant radicals. (Image credit: Theo A. Ellingsen.) This article belongs to the 10th Anniversary Collection of RACI and AAS Award papers. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Looking at the Iron Age in the inland Iberia and the Mediterranean influences: ceramics from the archaeological site of El Pueyo de Marcuello (Huesca, Spain).
- Author
-
Fabre, José, Pérez-Arantegui, Josefina, Lapuente, Pilar, and Arbués, María-José
- Subjects
- *
INDUCTIVELY coupled plasma atomic emission spectrometry , *ELITE (Social sciences) , *IRON Age , *CALCITE crystals , *MASS spectrometry - Abstract
• The studied materials highlighted the extent of the relationships in areas of the Iberian inland, also connected to the Mediterranean world, during the iron age. • The ceramic characterisation showed only a main production, with two body fabrics, but both used to produce all ceramic types, either traditional or ceremonial, manufactured in local workshops. • The material knowledge of these inland communities provided them the suitable ability to understand the fashions and industrial uses of the coastal circuits to replicate the characteristic elements of the social elites of that time with adequate mastery. The archaeological site called El Pueyo de Marcuello (Huesca, Spain) is an Iron Age urban settlement, geographically situated in inland Iberia, and dated of the second half of the first millennium BCE. The nature and manufacture of their archaeological remains allow identifying this site as a contact point for relevant exchanges, with remarkable connections with Central and Western Mediterranean cultures. These cultural influences and exchanges were investigated through the characterisation of the ceramic objects found during the archaeological excavations. More than forty fragments were studied, including some of the most peculiar ceramic types, and analysed by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and Mass Spectrometry (ICP-MS). The petrographic observations of the thin-sections highlighted two ceramic fabrics, with a similar matrix and mineralogy, but the second one using sparite crystals of crushed calcite as intentionally added temper. The statistical treatment of the chemical data supported the identification of two main compositional subgroups; both included very similar low-calcareous clay bodies. All these data allowed for highlighting a main production, with two body fabrics, but both used to produce all ceramic types, either traditional or ceremonial. These objects could have been largely manufactured in local workshops. The materials from El Pueyo de Marcuello highlighted the extent of the relationships in areas of the Iberian inland, also connected to the rhythms of Mediterranean world, during the Iron Age. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. A shift from contractarianism to 'characterisation': Assessing the ideal Australian approach for determining fiduciary duties in a commercial context.
- Author
-
Trovato, Claudio
- Subjects
- *
FIDUCIARY responsibility , *CONTRACTARIANISM (Ethics) , *BUSINESS negotiation , *CONTRACTS , *JUDGE-made law - Abstract
In the wake of excessive judicial reliance on a contractarian approach to the assessment of fiduciary duties in commercial contexts, both judicial and academic concern has been voiced as to whether such an approach is the most appropriate to ensure fair dealing. What's more, the emergence of novel commercial relationships facilitated by changing values in business and exponential leaps in the capabilities and use of technology warrant a reassessment of whether contractarianism is fit for the purpose of ushering in appropriate legal analysis so that such new developments can be appropriately facilitated. This article argues that contractarianism is not fit for that purpose and that the 'characterisation' of the relationship between parties is a superior and more equitable approach to determining the extent of fiduciary duties in commercial contexts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Investigation of the effect of EDTA modification on golden yellow removal: optimisation with response surface methodology.
- Author
-
Samdan, Canan, Demiral, Ilknur, and Bozkurt, Tugce
- Subjects
- *
CHEMICAL processes , *RESPONSE surfaces (Statistics) , *ACTIVATED carbon , *FUNCTIONAL groups , *SURFACE area - Abstract
Physical or chemical processes can enrich surface functional groups of activated carbon. EDTA grafting was applied to the carbon surface using a chemical treatment in this study. In this way, while there was no significant change in the surface area of the carbon, the Golden Yellow (GY) removal performance increased. The changes caused by EDTA grafting on the carbon surface have been revealed using various methods. Environmental conditions affecting the adsorption process were statistically investigated using Central Composite Design (CCD). Different equations were used to determine the stability, capacity, and mechanism of the GY removal with activated carbon and EDTA grafted carbon. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Compression behaviour and strengthening mechanisms for Cu hybrid composites.
- Author
-
Rajamani, D, Kumaresh Babu, S. P., and Natarajan, S.
- Subjects
HYBRID materials ,HYBRID systems ,STRAIN hardening ,COPPER ,CRYSTAL grain boundaries - Abstract
In this investigation, Cu-TiO
2 -Graphite hybrid composites were fabricated with variations in wt.% of TiO2 and fixed wt.% of Graphite contents through stir casting technique. The size of the grains measured after casting were 83 ± 04, 64 ± 10, 41 ± 10 and 29 ± 04 μm for 0, 3, 6, and 9 wt% hybrid composites, respectively. The addition of 1 wt.% graphite (Gr) was not only to enhance the mechanical and tribological properties but also to improve the wettability during casting. The influence of TiO2 and Gr in Cu-hybrid composite on compression test was investigated followed by characterisation studies involving XRD, EDS, TEM, EBSD. The results reveal that 9 wt% reinforced composite exhibits more strain hardening. Further, composite exhibits higher strength due to the presence of combined strengthening mechanisms such as grain boundary, Orowan and thermal expansion coefficient mismatch in commensurate with ceramic particle addition. Out of these, it is found that Orowan strengthening contributes significantly to the compression strength of the hybrid system investigated. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
23. Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels
- Author
-
Connor R. M. MacDonald and Emily R. Draper
- Subjects
characterisation ,electron microscopy ,gelators ,small angle scattering ,supramolecular materials ,Science ,Organic chemistry ,QD241-441 - Abstract
When evaluating soft self-assembling materials for use in any application, the structural or morphological characterisation is highly important. We know that the hierarchal molecular self-assembly of these materials into larger structures directly influences behaviours such as performance and stability. It is therefore imperative that these materials are characterised effectively over multiple length scales. Two effective methods of achieving this are small angle scattering (SAS) and imaging. Scattering giving us indirect information about the systems, whereas imaging is often looking at the material directly. In this review, we discuss the benefits, caveats and power of using both these techniques separately and together for the characterisation of supramolecular gels.
- Published
- 2024
- Full Text
- View/download PDF
24. A Comprehensive Review of the Multifaceted Characterisation Approaches of Dental Ceramics
- Author
-
Hanan Al-Johani, Julfikar Haider, Julian Satterthwaite, Marcia Borba, and Nick Silikas
- Subjects
dental glass ceramics ,characterisation ,flexural strength ,fracture toughness ,hardness ,machinability ,Medicine - Abstract
Ceramic dental restorative materials have growing popularity, albeit their brittle and stochastic nature are acknowledged shortcomings that impact the prosthesis lifespan. The mechanical performance of ceramics is dominated by the constitutional microstructural and fracture toughness mechanisms, as well as externally applied triggers. Thus, there is ongoing expanding research in the sphere of ceramic material engineering and thermal refinement, addressing concerns regarding toughness, machinability, reliability, stainability, and biodegradation. While the current trend in dental ceramic manufacturing has transitioned from micrometric crystalline sizes to submicrometric and nanometric ranges, there is an unclear understanding of the microstructural implications on ceramic behaviour. Therefore, this review covers the comprehensive characterisation approaches commonly employed in the scientific literature to describe the multifaceted performance aspects as well as clinical-related prerequisites of dental ceramics. Moreover, updated standardised testing parameters and performance thresholds pertaining to ceramic mannerisms are described in an attempt to translate their clinical applicability.
- Published
- 2024
- Full Text
- View/download PDF
25. Co-valorisation of cassava peel and rice husk to biofuel precursor via intermediate pyrolysis: Kinetics, thermodynamic and pyrolytic oil characterisation
- Author
-
Ezeh Ernest Mbamalu and Isah Yakub Mohammed
- Subjects
Biomass ,Characterisation ,Co-valorisation ,Intermediate pyrolysis ,Biofuel precursor ,Environmental technology. Sanitary engineering ,TD1-1066 ,Standardization. Simplification. Waste ,HD62 - Abstract
This study explored the co-valorisation of cassava peel and rice husk into biofuel precursors through pyrolysis. The research involved characterization of the biomass, and thermogravimetric analysis at heating rates of 5, 10, and 15 °C/min. An intermediate pyrolysis was conducted using a laboratory-scale setup with a stainless-steel reactor and a Swagelok double-ended tube, yielding pyrolytic oil for analysis. Proximate analysis revealed cassava peel (CP) contains 9.23 wt% ash, while rice husk (RH) has 16.50 wt% ash respectively, while the combined samples of cassava peel and rice husk (CS) had ash content of 74.27 wt%, fixed carbon of 70.07 wt%, and volatile matter of 75.72 wt%. The heating values for the samples were 17.15 MJ/kg, 15.22 MJ/kg, and 17.06 MJ/kg for cassava peel, rice husk, and combined sample respectively. Ultimate analysis indicated the following elemental compositions: CP (40.95 % C, 5.67 % H, 0.22 % N, 0.09 % S, 52.17 % O2), RH (40.15 % C, 5.98 % H, 0.41 % N, 0.78 % S, 52.68 % O2), and the CS (43.06 % C, 6.41 % H, 0.32 % N, 0.41 % S, 49.80 % O2). Kinetic and thermodynamic analysis from the distributed activation energy models revealed average activation energies of 184.95 kJ/mol (CP), 140.56 kJ/mol (RH), and 125.63 kJ/mol (CS). The pyrolysis products consist of 37.50 wt% pyrolytic oil, 11.12 wt% bio-char, and 51.38 wt% non-condensable gases. GC–MS analysis of the pyrolytic oil identified significant amounts of hydrocarbons, phenols, and phenol derivatives, suggesting potential for biofuel production. This study highlights the viability of combined biomass sources for biofuel production and waste to wealth utilization.
- Published
- 2024
- Full Text
- View/download PDF
26. Synthesis and application of choline chloride based deep eutectic solvents in liquid-liquid and solid-liquid assisted extraction of organophosphorus flame retardants from landfill leachate and sediment.
- Author
-
Sibiya, Innocentia Velaphi, Daso, Adegbenro Peter, and Okonkwo, Okechukwu Jonathan
- Subjects
- *
CHOLINE chloride , *POLLUTANTS , *OXALIC acid , *MELTING points , *EUTECTICS , *FIREPROOFING agents , *ORGANIC solvents - Abstract
The extraction of organic pollutants from environmental samples using green solvents has received a lot of interest recently. Simply said, this is due to their extremely low toxicity and volatility when compared to the common organic solvents. Therefore, many extraction exercises now include ionic solvents, as well as the more current deep eutectic solvents (DES). Hence, the current study reports on 1) the synthesis and characterisation of choline chloride/oxalic acid (1:1) and choline chloride/urea (1:2) deep eutectic solvents and 2) their application in liquid-liquid and solid-liquid assisted extraction of 14 targeted OPFRs from landfill leachate and sediment samples. The densities, refractive indices and melting points of the DES measured were 1.11 ± 0.15 g/mL, 1.14 ± 0.10 g/mL; 1.50 ± 0.12, 1.45 ± 0.20; and 12 ± 0.05°C, 35 ± 0.06–55 ± 0.05°C for choline chloride/urea (1:2) and choline chloride/oxalic acid (1:1) respectively. Choline chloride/urea (1:2) and choline chloride/oxalic acid (1:1) viscosities were 87.0 ± 0.20 kg·m −1·s −1 and 13.5 ± 0.14 kg·m −1·s −1 respectively. 1H NMR and FTIR confirmed the structures of the two DES. Recoveries using internal standards dTPP, dTBP, dTPrP and 13C18MTPP ranged from 59.9 ± 7.41–103 ± 5.32%; whereas the percent recoveries using CRM ranged from 85.7–117%. In the leachate (510–1433 ng/L) and sediment (725–1224 ng/g dw) samples from each landfill, 14 and 13 targeted OPFRs, respectively, were detected. The high recoveries and extraction of OPFRs demonstrated by the two DES imply that these could replace conventional organic solvents used to extract OPFRs from environmental media. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Facile synthesis of copper carbonate/cobalt carbonate/manganese carbonate and copper oxide/cobalt manganese oxide/manganese oxide as novel nanocomposites for efficient photocatalytic degradation of crystal violet dye.
- Author
-
Almehizia, Abdulrahman A., Al-Omar, Mohamed A., Naglah, Ahmed M., Hegazey, R.M., Al-Wasidi, Asma S., Katouah, Hanadi A., Basha, Maram T., Alghanmi, Reem M., Khedr, Abdalla M., Algethami, Faisal K., and Abdelrahman, Ehab A.
- Subjects
- *
FIELD emission electron microscopes , *TRANSMISSION electron microscopes , *COPPER , *SODIUM carbonate , *MANGANESE oxides , *GENTIAN violet - Abstract
In this work, copper carbonate/cobalt carbonate/manganese carbonate and copper oxide/cobalt manganese oxide/manganese oxide new nanocomposites were fabricated via precipitation of Cu(II)/Co(II)/Mn(II) solution using sodium carbonate and ignition of precipitate at 600°C for 3 h, respectively. Several instruments, including UV–Vis spectrophotometer, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), nitrogen gas sorption analyser, and field emission scanning electron microscope (FE-SEM), were used to characterise the fabricated nanocomposites. Energy dispersive X-ray investigation confirmed that the composite produced owing to precipitation by sodium carbonate comprises carbon, oxygen, manganese, cobalt, and copper where the weight percentages are equal to 27.15, 52.49, 5.59, 5.75, and 9.02%, respectively. In addition, the composite produced owing to ignition at 600°C for 3 h comprises oxygen, manganese, cobalt, and copper where the weight percentages are equal to 8.62, 31.50, 38.58, and 21.30%, respectively. Transmission electron microscope examination confirmed that the composites produced owing to precipitation by sodium carbonate and ignition at 600°C for 3 h comprise polyhedral and spherical shapes with an average diameter of 36.85 and 22.34 nm, respectively. The BET surface area, average pore size, and total pore volume of the composite produced owing to precipitation by sodium carbonate are 29.8662 m2/g, 2.1634 nm, and 0.0323 cc/g, respectively. In addition, the BET surface area, average pore size, and total pore volume of the composite produced owing to ignition at 600°C for 3 h are 33.3714 m2/g, 5.2308 nm, and 0.0873 cc/g, respectively. 0.06 g of the fabricated nanocomposites degrade 100% of 60 mL of 15 mg/L of crystal violet dye solution within 20 min in the presence of hydrogen peroxide under UV irradiation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Encapsulation of NiS and ZnS in analcime nanoparticles as novel nanocomposites for the effective photocatalytic degradation of orange G and methylene blue dyes.
- Author
-
Abdelwahab, Mohamed A., El Rayes, S.M., Kamel, Medhat M., and Abdelrahman, Ehab A.
- Subjects
- *
CONDUCTION bands , *METHYLENE blue , *PHOTODEGRADATION , *SODIUM dichromate , *ELECTROSTATIC fields - Abstract
Encapsulation of semiconductor materials in zeolites is one of the important types of composites that have been used as photocatalysts in the degradation of several organic dyes. The high surface area and uniform porous structure of the zeolite particles prevent the coagulation of the catalyst and ensure its stability and dispersion. The strong polarised electrostatic field of zeolites can decrease the energy consumption needed to facilitate the electrons transfer from the valence band to the conduction band. So, in this paper, ethylenediaminetetraacetic acid disodium salt dihydrate was used as an organic template to hydrothermally synthesise analcime nanoparticles. Besides, NiS and ZnS were encapsulated in the analcime nanoparticles as novel photocatalysts for the efficient degradation of orange G and methylene blue dyes. EDX, XRD, FE-SEM, FT-IR, HR-TEM, diffuse reflectance spectrophotometer, and nitrogen gas sorption instruments were used to characterise the novel photocatalysts. The XRD results confirmed that the encapsulation of NiS or ZnS in the analcime nanoparticles led to a decrease in the intensity of the peaks only without affecting their positions. The FE-SEM images confirmed that the encapsulation of NiS or ZnS in the analcime nanoparticles changed the surface of the analcime from small spherical particles into large spherical particles, in addition to the presence of irregular shapes. Besides, the nitrogen gas sorption analyser confirmed that the encapsulation of NiS or ZnS in the analcime nanoparticles led to an increase in average pore radius and total pore volume and a decrease in BET surface area. The percentage of photocatalytic degradation of orange G dye using NiS/analcime and ZnS/analcime composites is 63.60 and 70.50%, respectively. The percentage of photocatalytic degradation of methylene blue dye using NiS/analcime and ZnS/analcime composites is 88.76 and 98.31%, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Isolation and characterisation of zinc‐chelating peptides from tilapia (Oreochromis niloticus) protein hydrolysate.
- Author
-
Shen, Zehan, He, Shan, Abukhadra, Mostafa R., El‐Sherbeeny, Ahmed M., Zeng, Qingzhu, Liu, Lixiang, Deng, Shanggui, and Gao, Jingrong
- Abstract
Summary: This study aimed to isolate and characterise zinc‐chelating peptides from tilapia (Oreochromis niloticus) protein hydrolysate. The hydrolysate was fractionated using a multi‐ultrafiltration technique, yielding peptide fractions with molecular weights between 0.5 and 5 kDa. These fractions were further purified using immobilised metal ion affinity chromatography (IMAC‐Zn2+) and reverse high‐performance liquid chromatography (RP‐HPLC). Among the fractions obtained, the peptide fraction F211 exhibited a zinc‐binding capacity of 76.26 ± 2.46 mg g−1. Sequence analysis indicated that zinc binding occurred at amino acids on the F21 peptide and at valine or glutamate residues on the F22 peptide fraction. Structural characterisation revealed that amino nitrogen and oxygen atoms from carboxylate groups were the primary binding sites for Zn2+. Additionally, the zinc–peptide complex demonstrated strong thermal stability, which is significant for potential applications in food processing and storage, where maintaining the integrity of nutritional supplements under varying temperature conditions is crucial. These findings provide a feasible approach for the separation and purification of zinc‐binding peptides from tilapia protein hydrolysates and contribute to the understanding of the binding mechanisms between zinc and peptides. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Highly efficient removal of Pb2+ and Cu2+ ions using r-GO/PPY/SiO2 based nanosorbent.
- Author
-
Joshi, Naveen Chandra
- Subjects
- *
NANOCOMPOSITE materials , *GRAPHENE oxide , *WATER pollution , *WASTEWATER treatment , *ADSORPTION capacity - Abstract
In the treatment of wastewater incorporating inorganic and organic contaminants, graphene oxide and polymer-based nanocomposites have gained a lot of interest. In the current study, reduced graphene oxide (r-GO), polypyrrole (PPY) and silica (SiO2) based nanocomposite material (r-GO/PPY/SiO2) was utilised as an effective adsorbent for the removal of Pb2+ and Cu2+ ions from contaminated water. The r-GO/PPY/SiO2 was synthesised using an efficient and low-cost approach, and it was then analysed using various techniques. Under the employed adsorption conditions, this material was demonstrated to be a very efficient adsorbent for the decontamination of Pb2+ and Cu2+ ions in wastewater. The highest adsorption capacities of r-GO/PPY/SiO2 for Pb2+ and Cu2+ ions were evaluated to be 19.305 and 23.148 mg/g. The pseudo-second order rate constants have been determined as 90.9 and 66.225 mg/g/min for Pb2+ and Cu2+ ions, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Characterising assurance: scepticism and mistrust in cyber security.
- Author
-
Spencer, Matt
- Abstract
This paper presents an analysis of recent transformations in cyber security assurance, a field of evaluation that aims to establish whether technical products are secure. I work from a set of narratives about problems with assurance, drawn from interviews with practitioners based in the UK. I focus on characterisation: the stories practitioners tell, the cast of characters that populate them, and how such stories act to problematise the domain. Mistrust, it is argued, can be understood in terms of the capacities of sceptical narratives to efface the power of security certifications to be taken on 'face value.' A text-based view of mistrust is thus developed that can be differentiated from the conventional disposition-centred view. Examining mistrust, then, leads us to ask not how to change dispositions to make them 'more trusting,' but rather to critical questions about the palette of characters that feature in cyber security. I close the essay by offering a commentary on the way characterisation leads to the anticipation of experts in formulations of policy and on the possible 'counter-characterisation' that might be developed, for instance around 'caring' characters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Jerusalem artichoke diversity in Türkiye: comparative analysis of clone and organ-based biochemical composition.
- Author
-
Hanci, Fatih, Inan, Zelal, Dalda Şekerci, Akife, and Uzun, Aydın
- Subjects
JERUSALEM artichoke ,PRINCIPAL components analysis ,GERMPLASM ,PATH analysis (Statistics) ,VITAMIN C - Abstract
In this study, biochemical analyses were performed for the first time on 22 different Jerusalem artichokes clones collected from different regions of Türkiye and samples from three different organs of each clone, considering the interaction effects. As a result of the study, the interaction effect of clones and sampled organs was found significant for total flavonoids, ascorbic acid, total chlorophyll, pH, H
2 O2 removal capacity, total dry matter, water soluble dry matter and antioxidant capacity via FRAP. According to the correlation analysis, the highest coefficient among the parameters in the tuber was between titratable acidity and total phenolic matter (0,576). Principal component analysis was used to assess the degree to which the parameters explained the variation in the gene pool. Factors directly and indirectly affecting the amount of water-soluble dry matter in the tuber were examined by path analysis. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
33. Seracam: characterisation of a new small field of view hybrid gamma camera for nuclear medicine
- Author
-
Sarah L. Bugby, Andrew L. Farnworth, William R. Brooks, and Alan C. Perkins
- Subjects
Gamma camera ,Portable scintigraphy ,Characterisation ,Thyroid ,Gastric emptying ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Background Portable gamma cameras are being developed for nuclear medicine procedures such as thyroid scintigraphy. This article introduces Seracam® – a new technology that combines small field of view gamma imaging with optical imaging – and reports its performance and suitability for small organ imaging. Methods The count rate capability, uniformity, spatial resolution, and sensitivity for 99mTc are reported for four integrated pinhole collimators of nominal sizes of 1 mm, 2 mm, 3 mm and 5 mm. Characterisation methodology is based on NEMA guidelines, with some adjustments necessitated by camera design. Two diagnostic scenarios – thyroid scintigraphy and gastric emptying – are simulated using clinically relevant activities and geometries to investigate application-specific performance. A qualitative assessment of the potential benefits and disadvantages of Seracam is also provided. Results Seracam’s performance across the measured characteristics is appropriate for small field of view applications in nuclear medicine. At an imaging distance of 50 mm, corresponding to a field of view of 77.6 mm × 77.6 mm, spatial resolution ranged from 4.6 mm to 26 mm and sensitivity from 3.6 cps/MBq to 52.2 cps/MBq, depending on the collimator chosen. Results from the clinical simulations were particularly promising despite the challenging scenarios investigated. The optimal collimator choice was strongly application dependent, with gastric emptying relying on the higher sensitivity of the 5 mm pinhole whereas thyroid imaging benefitted from the enhanced spatial resolution of the 1 mm pinhole. Signal to noise ratio in images was improved by pixel binning. Seracam has lower measured sensitivity when compared to a traditional large field of view gamma camera, for the simulated applications this is balanced by advantages such as high spatial resolution, portability, ease of use and real time gamma-optical image fusion and display. Conclusion The results show that Seracam has appropriate performance for small organ 99mTc imaging. The results also show that the performance of small field of view systems must be considered holistically and in clinically appropriate scenarios.
- Published
- 2024
- Full Text
- View/download PDF
34. Immobilisation of catalase purified from mushroom (Hydnum repandum) onto glutaraldehyde-activated chitosan and characterisation: Its application for the removal of hydrogen peroxide from artificial wastewater
- Author
-
Tabaru Işıl Nur and Türkhan Ayşe
- Subjects
catalase ,three-phase partitioning ,immobilisation ,characterisation ,h2o2 removal ,Chemistry ,QD1-999 - Abstract
Hydrogen peroxide (H2O2) is a chemical that is widely used in many industrial processes, and, except at certain concentrations, it is toxic in biological systems such as water and air. Among enzymes, catalases are important industrial enzymes because of their role in the conversion of hydrogen peroxide to water and molecular oxygen. Herein, catalase (CAT) from Hydnum repandum was purified 3.02-fold with a yield of 68.10% by three-phase partitioning (TPP) for the first time. The purified catalase was immobilised on glutaraldehyde-activated chitosan (Glu-Cts), and its applicability for the removal of hydrogen peroxide released from industrial processes was investigated. The results of the present study showed that the optimum pH and temperature were found to be 7.0 and 30°C for both free and immobilised catalase (CAT-Glu-Cts). The catalytic efficiency (V max/K m) of the immobilised enzyme increased 8-fold compared to the free enzyme. CAT-Glu-Cts was shown to have better pH, thermal stability, and storage stability than free CAT. In this study, >96% of 6 mM, 15 ve 24 mM H2O2 was removed from artificial wastewater after 2 h using immobilised catalase. We expect that CAT-Glu-Cts, obtained by purifying a plant-derived catalase and immobilising it into an environmentally friendly and biocompatible material, is a promising candidate that can be safely used for H2O2 removal in various branches of industry.
- Published
- 2024
- Full Text
- View/download PDF
35. A Novel Kunitz Trypsin Inhibitor from Enterolobium gummiferum Seeds Exhibits Antibiofilm Properties against Pathogenic Yeasts.
- Author
-
da Silva, Matheus M., de Oliveira, Caio F. R., Almeida, Claudiane V., Sobrinho, Ismaell A. S., and Macedo, Maria L. R.
- Subjects
- *
PEPTIDASE , *CIRCULAR dichroism , *PHYSIOLOGY , *TRYPSIN , *YEAST - Abstract
Plant peptidase inhibitors play crucial roles in plant defence mechanisms and physiological processes. In this study, we isolated and characterised a Kunitz trypsin inhibitor from Enterolobium gummiferum seeds named EgPI (E. gummiferum peptidase inhibitor). The purification process involved two chromatography steps using size exclusion and hydrophobic resins, resulting in high purity and yield. EgPI appeared as a single band of ~20 kDa in SDS-PAGE. Under reducing conditions, the inhibitor exhibited two polypeptide chains, with 15 and 5 kDa. Functional characterisation revealed that EgPI displayed an inhibition stoichiometry of 1:1 against trypsin, with a dissociation constant of 8.4 × 10−9 mol·L−1. The amino-terminal sequencing of EgPI revealed the homology with Kunitz inhibitors. Circular dichroism analysis provided insights into the secondary structure of EgPI, which displayed the signature typical of Kunitz inhibitors. Stability studies demonstrated that EgPI maintained the secondary structure necessary to exhibit its inhibitory activity up to 70 °C and over a pH range from 2 to 8. Microbiological screening revealed that EgPI has antibiofilm properties against pathogenic yeasts at 1.125 μmol·L−1, and EgPI reduced C. albicans biofilm formation by 82.7%. The high affinity of EgPI for trypsin suggests potential applications in various fields. Furthermore, its antibiofilm properties recommended its usefulness in agriculture and antimicrobial therapy research, highlighting the practical implications of our research. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Potential of GTL biosolids in a circular economy: investigating blending, pyrolysis, activation, and characterisation.
- Author
-
Zuhara, Shifa, Zakaria, Yahya, and McKay, Gordon
- Subjects
CIRCULAR economy ,BIOCHAR ,SEWAGE sludge ,X-ray powder diffraction ,X-ray photoelectron spectroscopy ,PYROLYSIS - Abstract
Qatar's population has been rapidly increasing in recent years, and the country's long-term vision, QNV 2030, aims to sustain this growth by transforming the country into a sustainable state. One aspect of this vision is to convert waste into value-added products, which will reduce the environmental and spatial burden associated with waste in Qatar, while contributing to a circular economy. This study describes methods for producing biochar and activated carbon (AC) from gas-to-liquids derived biosolids, cardboard waste and mixed samples using pyrolysis and activation techniques. The characterisation of products revealed that the yield of biochar samples was higher than AC, and that the pH of the biochar samples was more alkaline than the feed samples due to metals after pyrolysis and reduced acid surface functional groups. Proximate analysis of samples showed lowered moisture and enhanced ash in feeds upon pyrolysis and activation due to increased temperature with reduced volatile content. AC application to water treatment is considered a potential benefit due to the increased surface area, pore volume and magnetic properties based on the Brunauer–Emmett–Teller (BET) and X-ray Powder Diffraction (XRD) analysis. The X-ray photoelectron spectroscopy (XPS) analysis also showed increased –CO
3 /O–C = O and potassium in the ACs as a result of potassium carbonate activation. The study proposes various applications that can support a circular economy, but future studies should investigate actual applications and potential health and environmental effects and evaluate the feasibility and environmental impact of production methods. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
37. Will substitutes in EU private international law: deathbed gifts and contracts for the benefit of a third party upon death.
- Author
-
Wendland, Charlotte
- Subjects
- *
INHERITANCE & succession , *CONFLICT of laws , *CONTRACTS , *GIFTS - Abstract
Will substitutes exist in many legal systems, including those of Member States of the European Union. Two of these will substitutes are deathbed gifts and contracts for the benefit of a third party upon death. Both instruments are located at the intersection of succession law and contract law and are therefore difficult to characterise for the purposes of private international law. One could either characterise them as succession instruments in the sense of the EU Succession Regulation or as contracts in the sense of the Rome I Regulation. This article analyses the different options on how to characterise these will substitutes by taking into account the wording of both Regulations, comparative analysis of the substantive law, the likelihood of adaptation and the recent judgment by the Court of Justice of the European Union (CJEU) on this matter. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Exploring the properties of Garcinia indica Linn rind powder and its possible usage in food industry.
- Author
-
Awari, Ankita, Kumar, Mukul, Kaushik, Deepika, Oz, Emel, Proestos, Charalampos, Zeng, Maomao, Brennan, Charles, Ahmed, Mukhtar, and Oz, Fatih
- Subjects
- *
GARCINIA , *FOOD industry , *BLOOD sugar , *POWDERS , *REGULATION of body weight , *FUNCTIONAL foods , *PLANT extracts - Abstract
Summary: The study investigates, the potential utilisation of the Garcinia indica linn rind powder as a valuable and healthy ingredient for food industry. Techno‐functional properties revealed the functional attributes which is crucial for product development. Characterisation of the powder and extract revealed the physical, chemical, and structural properties through FTIR, HPLC, and SEM. Therefore, moisture content (5.45%), ash content (2.80%), fibre content (7.56%), and fat content (9.54%) were reported in G. indica linn rind. Phytochemical analysis indicated significant levels of phenolic and flavonoid compounds, suggesting antioxidant potential, supported by inhibition in the DPPH assay with IC50 value of 485.1 μg/mL. In‐vitro assays revealed inhibitory effects on α‐amylase with IC50 value of 58.43 μg/mL and glucose with an IC50 value of 0.39 μg/mL, indicating potential benefits in blood glucose management and weight control. Overall, G. indica rind powder shows promise as a natural ingredient with diverse applications in functional foods and nutraceuticals, offering potential health benefits through innovative product formulations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Localised Objective Characterisation Assessment of Lymphoedema (LOCAL): Using High-Frequency Ultrasound, Bioelectrical Impedance Spectroscopy and Volume to Evaluate Superficial Tissue Composition.
- Author
-
Sanderson, Jennifer, Tuttle, Neil, Box, Robyn, Reul-Hirche, Hildegard, and Laakso, E-Liisa
- Subjects
- *
BIOELECTRIC impedance , *IMPEDANCE spectroscopy , *LYMPHEDEMA , *VOLUME measurements , *RESEARCH personnel - Abstract
Lymphoedema tissue is characterised by excess free fluid and structural changes to the extracellular matrix (ECM) in the form of fibrotic and fatty deposition. These tissue characteristics are integral to the assessment of lymphoedema progression; however, clinicians and researchers often focus on changes in the free fluid, volume and function of lymphatic vasculature to inform practice. Subsequently, little is known about the effect of clinical interventions on lymphoedema tissue composition. This article presents a novel approach to classify lymphoedema tissue. The Localised Objective Characterisation Assessment of Lymphoedema (LOCAL) classification combines diagnostic and clinically meaningful objective assessment thresholds to infer lymphoedema pathophysiological changes in tissue layers. The LOCAL classification method was verified using data from fifteen women with unilateral breast cancer-related lymphoedema who were evaluated at three sites on each arm using high-frequency ultrasound (HFUS), bio-electrical impedance spectroscopy (BIS) and volume measurements. Participants exhibited an uneven distribution of volume between the proximal and distal segments of the arm (p = 0.023), with multiple tissue compositional categories observed across sites on the same limb (p < 0.001). The LOCAL method demonstrated utility in categorising a diverse range of lymphoedema tissue layer changes beyond what can be ascertained from whole-limb measures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Development and Optimisation of Olive Oilinfused Emulgel from Andrographis Extract Using Quality by Design (QbD) Methodology.
- Author
-
Sirisha Mulukuri, N. V. L., Devi, Kusum, Satheesh Madhav, N. V., Prabhakar, T., Ranjitha, and Kumar, Pankaj
- Subjects
SUPERCRITICAL fluid extraction ,EXPERIMENTAL arthritis ,SESAME oil ,LABORATORY rats ,ALUMINUM tubes ,ANDROGRAPHIS paniculata ,XANTHAN gum ,HYDROXYTYROSOL - Published
- 2024
- Full Text
- View/download PDF
41. Proteomic Characterization of Human Placenta: Insights into Potential Therapeutic Applications for Osteoarthritis.
- Author
-
James, Jithu Jerin, Sandhya, K. V., Sridhar, K. N., Sudarson, S., Basavaraj, B. V., and Bharath, S.
- Abstract
Biologics have become increasingly prominent as therapeutics in recent years due to their innate immune-privileged nature, biocompatibility, and high levels of protein biofactors. The aim of the study is to characterise the biologic, lyophilized human placenta (LHP) and explore its therapeutic potential for osteoarthritis (OA). The presence of six bioactive constituents that regulate cell-extracellular matrix interaction was identified by liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF/MS). Metalloproteinase inhibitor 3 (TIMP3), alpha-1 anti-trypsin (a1AT), basic fibroblast growth factor (bFGF), and transforming growth factor β1 (TGFβ1) were detected and quantified using ELISA. The total protein content present in LHP by Bradford assay was found to be 409.35 ± 0.005 μg/ml. The analytical techniques such as Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR), solid state carbon-13 Nuclear Magnetic Resonance (ssC
13 NMR) spectroscopy, and Differential Scanning Calorimetry (DSC) revealed the secondary structure and conformational stability of LHP. X-Ray diffraction (XRD) studies showed its amorphous nature. Bioactivity assessment of LHP was performed in human keratinocytes (HaCaT) and human dermal fibroblasts (HDF) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The LHP was highly proliferative against skin cells and non-toxic, based on the findings of the bioactivity assay. LHP has the potential to be used as a therapeutic agent for OA, as its characterisation unveiled its physical stability, significant concentration of bioactive components that are pertinent to cartilage repair and its conformational stability. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
42. Extraction optimisation, purification, characterisation, antibacterial, and antioxidant activity of polysaccharide from Platycodon grandiflorus leaves.
- Author
-
Sun, J. R., Wang, D. H., Fu, D. D., and Gu, S. B.
- Subjects
SALMONELLA typhimurium ,CHINESE medicine ,ANTIBACTERIAL agents ,PSEUDOMONAS aeruginosa ,FREE radicals - Abstract
Platycodon platycodon is a traditional Chinese medicine homologous food, which is rich in stems and leaves, but mostly discarded. In the present work, the extraction process of polysaccharide from P. grandiflorus leaves (PGLP) was optimised. After isolation and purification, the antibacterial and antioxidant activities of the polysaccharide were studied. The extraction rate was highest under the conditions of ultrasonic power 280 W, solid-tosolvent ratio 1:22 (w/v), extraction temperature 79°C, and extraction time 3.5 h, reaching 10.11%, which was consistent with the model predicted value. The crude polysaccharide was isolated and purified by DEAE-52 cellulose chromatography and Sephadex G-100 chromatography column, and two components PGLP-2-1 and PGLP-4-1 were obtained. UV-Vis, FT-IR, and XRD analyses showed that PGLP-2-1 and PGLP-4-1 had typical characteristics of polysaccharides. PGLP-2-1 had the highest antibacterial activity against Staphylococcus aureus, and the inhibitory zone diameter reached 17.46 mm; in addition, it had weaker antibacterial activity against Pseudomonas aeruginosa, Salmonella Typhimurium, and Bacillus subtilis. PGLP-4-1 had a weak antibacterial activity against Pseudomonas aeruginosa, Salmonella Typhimurium, and Staphylococcus aureus, and the inhibitory zone diameters were 12.24, 11.35, and 12.52 mm, respectively. PGLP-2-1 had strong scavenging ability on superoxide anion, hydroxyl, DPPH, and ABTS free radicals, and the highest scavenging rate reached 86.68, 80.96, 74.82, and 78.88%, respectively. PGLP-4-1 also had strong scavenging ability on superoxide anion, hydroxyl, DPPH, and ABTS free radicals; and the highest scavenging rate reached 75.04, 72.23, 60.56, and 50.25%, respectively. The results indicated that PGLP-2-1 and PGLP-4-1 had strong antioxidant activity, and the antioxidant activity of PGLP-2-1 was higher than PGLP-4-1. The present work provided a theoretical basis for the comprehensive development and utilisation of P. platycodon leaves. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Bioactive Compounds in the Oils of the Autochthonous Slovenian Olive Varieties 'Buga', 'Črnica' and 'Drobnica'.
- Author
-
Valenčič, Vasilij, Bučar-Miklavčič, Milena, and Podgornik, Maja
- Subjects
OLIVE oil ,OLEIC acid ,LINOLEIC acid ,CLIMATE change ,BIOACTIVE compounds - Abstract
The adaptation of autochthonous olive varieties to local soil and climatic conditions can lead to a unique chemical composition and characteristics of olive oils that may differ from the generally accepted quality standards set out in the International Olive Oil Council strategy documents and EU regulations. Therefore, the fatty acid composition, biophenol, tocopherol, sterol and triterpenic dialcohol content and composition of the autochthonous Slovenian olive varieties 'Buga', 'Črnica' and 'Drobnica' were studied for a three-year period with the aim of valorising the characteristics of the three olive varieties. Standardised and accredited analytical methods in accordance with SIST EN ISO/IEC 17025:2017 were applied. The results of the investigation showed that the highest average amount of oleic acid (75.75%) was found in the oils of the 'Črnica' variety, followed by the 'Drobnica' (72.06%) and the 'Buga' (68.73%). All three varieties are a good source of total biophenols ('Buga' 616 mg/kg, 'Drobnica' 569 mg/kg and 'Črnica' 427 mg/kg) and α-tocopherol ('Buga' 378 mg/kg, 'Drobnica' 279 mg/kg, and 'Črnica' 243 mg/kg). 'Buga' and 'Drobnica' are characterised by high amounts of total sterols, 2468 mg/kg and 2391 mg/kg, respectively, while 'Črnica' oils, in comparison, showed a lower average value of total sterols (1351 mg/kg). Due to their exceptional chemical composition, 'Buga', 'Črnica' and 'Drobnica' show great potential for the further cultivation and valorisation of traditional olive oil production in the region, thus contributing to the preservation of biodiversity and local traditions. The quality parameters of olive oil from the autochthonous Slovenian olive varieties 'Buga', 'Črnica' and 'Drobnica' also fulfil the limits for extra virgin olive oil according to the Commission Delegated Regulation (EU) 2022/2104, despite local climatic influences. However, accelerated growth due to climatic changes affecting early harvest can lead to them falling outside these limits, which was observed in particular for the 'Buga' variety in terms of the linoleic acid content. This study emphasises the importance of timing the harvest to achieve optimum maturity and meet EU quality standards, taking into account the genetic makeup of the varieties and their response to the current climatic conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Seracam: characterisation of a new small field of view hybrid gamma camera for nuclear medicine.
- Author
-
Bugby, Sarah L., Farnworth, Andrew L., Brooks, William R., and Perkins, Alan C.
- Subjects
- *
SCINTILLATION cameras , *NUCLEAR medicine , *COLLIMATORS , *SIGNAL-to-noise ratio , *TECHNOLOGICAL innovations , *IMAGE fusion - Abstract
Background: Portable gamma cameras are being developed for nuclear medicine procedures such as thyroid scintigraphy. This article introduces Seracam® – a new technology that combines small field of view gamma imaging with optical imaging – and reports its performance and suitability for small organ imaging. Methods: The count rate capability, uniformity, spatial resolution, and sensitivity for 99mTc are reported for four integrated pinhole collimators of nominal sizes of 1 mm, 2 mm, 3 mm and 5 mm. Characterisation methodology is based on NEMA guidelines, with some adjustments necessitated by camera design. Two diagnostic scenarios – thyroid scintigraphy and gastric emptying – are simulated using clinically relevant activities and geometries to investigate application-specific performance. A qualitative assessment of the potential benefits and disadvantages of Seracam is also provided. Results: Seracam's performance across the measured characteristics is appropriate for small field of view applications in nuclear medicine. At an imaging distance of 50 mm, corresponding to a field of view of 77.6 mm × 77.6 mm, spatial resolution ranged from 4.6 mm to 26 mm and sensitivity from 3.6 cps/MBq to 52.2 cps/MBq, depending on the collimator chosen. Results from the clinical simulations were particularly promising despite the challenging scenarios investigated. The optimal collimator choice was strongly application dependent, with gastric emptying relying on the higher sensitivity of the 5 mm pinhole whereas thyroid imaging benefitted from the enhanced spatial resolution of the 1 mm pinhole. Signal to noise ratio in images was improved by pixel binning. Seracam has lower measured sensitivity when compared to a traditional large field of view gamma camera, for the simulated applications this is balanced by advantages such as high spatial resolution, portability, ease of use and real time gamma-optical image fusion and display. Conclusion: The results show that Seracam has appropriate performance for small organ 99mTc imaging. The results also show that the performance of small field of view systems must be considered holistically and in clinically appropriate scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. GREEN SYNTHESIS OF COPPER NANOPARTICLES FROM ALOE VERA LEAF GEL CONCENTRATE AND ITS CHARACTERISATION.
- Author
-
Khanna, Vibhu, Singh, Saurabh, Sudhakar, Kalvatala, Baghel, Dileep Singh, Kumar, Bimlesh, Wadhawa, Sheetu, and Pandey, Narendra Kumar
- Subjects
- *
ENERGY dispersive X-ray spectroscopy , *COPPER sulfate , *ALOE vera , *COPPER , *SCANNING electron microscopy , *REDUCING agents - Abstract
Copper nanoparticles were synthesized from Aloe vera leaf gel extract concentrate from 0.1 Molar Copper sulphate pentahydrate solution. The Aloe vera gel concentrate and copper sulphate solution during the process were subjected to spectrophotometric absorption studies. Prepared nanoparticles were observed for size, zeta potential and polydispersity index, scanning electron microscopy, and energy dispersive X-ray analysis. The results showed that the size of elemental copper synthesized with the help of Aloe vera leaf gel extract concentrate was 272nm. SEM analysis confirmed the morphology of synthesized nanoparticles (spherical shapes). EDX studies further confirmed the presence of 67.21% elemental copper in newly synthesized nanoparticles prepared from Aloe vera leaf gel concentrate. The process of green synthesis uses eco-friendly resources to increase biological safety. The Aloe vera leaf gel extract concentrate efficiently served as a reducing and a capping agent to reduce the size of copper particles to the nanoparticle range. The method is low in cost and saves energy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Characterisation of the observed diurnal cycle of precipitation over the Maritime Continent.
- Author
-
Mustafa, Jack M., Matthews, Adrian J., Hall, Rob A., Heywood, Karen J., and Azaneu, Marina V. C.
- Subjects
- *
COASTS , *CONTINENTS , *SEASONS - Abstract
This study investigates the temporal and spatial complexities of the mean diurnal cycle (DC) of precipitation over the Maritime Continent during the wet season using the Integrated Multi‐satellite Retrievals for GPM (IMERG) data product and highlights systematic inaccuracies of amplitude and phase representation using the first diurnal harmonic (FDH). The first‐order nature of the DC of precipitation is already well documented, typically featuring heavy precipitation over near‐coastal land areas in the late afternoon and evening followed by maximum precipitation overnight over the surrounding seas, with offshore propagation evident in places. The DC is often described concisely in terms of an amplitude and phase based on the FDH parameters, however the omission of higher‐order components of variability results in the FDH parameters being poor indicators of the magnitude and peak time of diurnal variability in many locations. This study improves the accuracy of the amplitude and phase parameters by characterising the DC using two novel waveforms—a skew‐permitting waveform and a spike‐permitting waveform—which are constructed to characterise single‐peak cycles with rapid transitions more accurately. Key characterisation improvements include correction of a phase lag (averaging approximately 1 h) over near‐coastal land areas and capture of the short‐lasting but extreme peak in precipitation rate over Java which increases the amplitude by the order of 20%. The new skew parameter shows that locations close to coastlines experience rapid intensification and gradual weakening of diurnal precipitation, while there is a tendency toward gradual intensification and rapid weakening far inland and offshore. The new spike parameter shows that near‐coastal land experiences a brief and precisely timed peak in precipitation, whereas diurnal activity over inland locations is longer‐lasting and less precisely timed, and waters surrounding Java experience a precisely timed suppression of precipitation. Other potential applications of the novel waveforms used in this study are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Ground-Based Characterisation of a Compact Instrument for Gamma-ray Burst Detection on a CubeSat Platform.
- Author
-
Dunwoody, Rachel, Murphy, David, Uliyanov, Alexey, Mangan, Joseph, Doyle, Maeve, Thompson, Joseph, de Barra, Cuan, Hanlon, Lorraine, McKeown, David, Shortt, Brian, and McBreen, Sheila
- Subjects
SPACE industrialization ,CUBESATS (Artificial satellites) ,PHOTOMULTIPLIERS ,ORBITS (Astronomy) ,SPACE vehicles ,GAMMA ray bursts - Abstract
Gamma-ray bursts (GRBs) are intense and short-lived cosmic explosions. Miniaturised CubeSat-compatible instruments for the study of GRBs are being developed to help bridge the gap in large missions and assist in achieving full sky coverage. CubeSats are small, compact satellites conforming to a design standard and have transformed the space industry. They are relatively low-cost and are developed on fast timescales, which has provided unparalleled access to space. This paper focuses on GMOD, the gamma-ray module, onboard the 2U CubeSat EIRSAT-1, launched on December 1st 2023. GMOD is a scintillation-based instrument with a cerium bromide crystal coupled to an array of sixteen silicon photomultipliers, designed for the detection of GRBs. The characterisation of GMOD in the spacecraft, along with the validation of an updated spacecraft MEGAlib model is presented and this approach can be followed by other CubeSats with similar science goals. The energy resolution of the flight model is 7.07% at 662 keV and the effective area peaks in the tens to hundreds of keV, making it a suitable instrument for the detection of GRBs. An investigation into the instrument's angular response is also detailed. The results from this characterisation campaign are a benchmark for the instrument's performance pre-launch and will be used to compare with the detector's performance in orbit. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Characterisation, Metabolite Profile, and Antioxidant Activity of Silver Nanoparticles Synthesised Using the Algae Palmaria palmata.
- Author
-
Savitri, Evika S., Auliyah, Hafidah N., and Muchtaromah, Bayyinatul
- Subjects
DULSE ,SILVER nanoparticles ,SCANNING electron microscopy ,PHYTOCHEMICALS ,ANTIOXIDANTS - Abstract
Palmaria palmata contains phytochemicals with potential antioxidant properties, such as polyphenols and mycosporins (MAAs). Phycoerythrin and phycocyanin are pigments found in the red algae species Palmaria palmata. It is believed that P. palmata derived silver nanoparticles have excellent antioxidant activity. This study aims to determine the morphological, metabolite profile and antioxidant activity of silver nanoparticle compounds synthesised using P. palmata. The green synthesis of silver nanoparticles was performed using P. palmata as a bioreductant. The morphological characteristics observed were the size and shape of the particles, which were observed using the particle size analyser (PSA) and scanning electron microscopy (SEM). Biochemical characteristics studied were secondary metabolite profiles and antioxidant activity of silver nanoparticle compounds using P. palmata. The metabolite profile was tested using High-Performance Liquid Chromatography (HPLC). The antioxidant activity was tested using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method with ascorbic acid as the positive control. The study showed that P. palmata AgNPs are spherical, with a size of 185.5 nm. P. palmata AgNP contains phenolic group metabolites of gallic acid at a retention time of 2.74 minutes with a peak height of 89.248 mAu and a relative peak area of 98.73%. The antioxidant activity of AgNP synthesised using P. palmata possesses an IC
50 value of 17.113 ± 1.584 ppm, indicating a more robust antioxidant activity compared to the extract of P. palmata, which had an IC50 value of 33.875 ± 11.238 ppm. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
49. Ripening and Rotting Heroes: Growth, Decay, and Narrative Abjection in Anthony Trollope's The Small House at Allington and The Last Chronicle of Barset.
- Author
-
Last, Stephanie
- Subjects
- TROLLOPE, Anthony, 1815-1882, SMALL House at Allington, The (Book : Trollope)
- Abstract
This essay argues that Anthony Trollope introduces a framework of character growth and decay, evinced through organic metaphors of ripening and rotting, to distinguish good and bad characters in The Small House at Allington and The Last Chronicle of Barset. By comparing a developing protagonist with a mature one who enters a phase of decline, we see how Trollope's commitment to nuanced characterisation is disrupted by his didactic aim of designating, and then torturing, patently bad figures. An analysis of the psychologies and aesthetics of character, framed around Julia Kristeva's theory of abjection, shows how Trollope figures two subtly paralleled protagonists as opposites, establishing one as a palatable figure and the other as a nauseating one. The isolation of a rotten character serves a dual purpose: Trollope teaches his moral lessons by subjecting the character to physical, psychological, and structural decay, while narrative progression, culminating in the imperative happy ending, is structured around the abjection of the bad object. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Experimental characterisation and statistical modelling of woven carbon fibre weld conductors for electrical resistance welding of thermoplastic composites.
- Author
-
Sänger, Alexander, Endrass, Manuel, and Kupke, Michael
- Subjects
RESISTANCE welding ,ELECTRICAL conductors ,THERMOPLASTIC composites ,WELDING ,STATISTICAL models ,FIBERS - Abstract
Resistance welding of high-performance thermoplastic composites is a promising joining technique for the structural assembly of aerospace components. Knowledge of the weld conductor resistance as a function of its dimensions, as well as external boundary conditions such as contact preparation and pressure, can be used to scale welding parameters. This paper presents a comprehensive review on the weld conductor contact preparation, length, width and contact pressure dependent resistance with respect to the Toray 5HS T300JB carbon woven prepreg 281 gsm fibre architecture. The study is based on a 4-wire resistance measurement of the carbon fibre fabric weld conductors and was conducted to provide a solid basis for defining the weld conductor's resistance, considering the dependence on length, width and contact pressure. The experimentally determined resistance values were approximated using linear and non-linear regression functions and combined into a general formulation with respect to the investigated carbon fibre fabric architecture. The least squares fit of experimental versus model data confirmed a very high model confidence. Thus, the model allows a simplified transfer of electrical properties for process pre-design and scaling considering weld conductors with the same fibre architecture. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.