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  1. Lim WTH, Ooi EH, Foo JJ, Ng KH, Wong JHD, Leong SS
    Ultrasonics, 2023 Aug;133:107046.
    PMID: 37247461 DOI: 10.1016/j.ultras.2023.107046
    The application of ultrasound shear wave elastography for detecting chronic kidney disease, namely renal fibrosis, has been widely studied. A good correlation between tissue Young's modulus and the degree of renal impairment has been established. However, the current limitation of this imaging modality pertains to the linear elastic assumption used in quantifying the stiffness of renal tissue in commercial shear wave elastography systems. As such, when underlying medical conditions such as acquired cystic kidney disease, which may potentially influence the viscous component of renal tissue, is present concurrently with renal fibrosis, the accuracy of the imaging modality in detecting chronic kidney disease may be affected. The findings in this study demonstrate that quantifying the stiffness of linear viscoelastic tissue using an approach similar to those implemented in commercial shear wave elastography systems led to percentage errors as high as 87%. The findings presented indicate that use of shear viscosity to detect changes in renal impairment led to a reduction in percentage error to values as low as 0.3%. For cases in which renal tissue was affected by multiple medical conditions, shear viscosity was found to be a good indicator in gauging the reliability of the Young's modulus (quantified through a shear wave dispersion analysis) in detecting chronic kidney disease. The findings show that percentage error in stiffness quantification can be reduced to as low as 0.6%. The present study demonstrates the potential use of renal shear viscosity as a biomarker to improve the detection of chronic kidney disease.
    Matched MeSH terms: Viscosity
  2. Shimolina L, Gulin A, Khlynova A, Ignatova N, Druzhkova I, Gubina M, et al.
    Int J Mol Sci, 2023 Jul 29;24(15).
    PMID: 37569560 DOI: 10.3390/ijms241512186
    The cell membrane is an important regulator for the cytotoxicity of chemotherapeutic agents. However, the biochemical and biophysical effects that occur in the membrane under the action of chemotherapy drugs are not fully described. In the present study, changes in the microviscosity of membranes of living HeLa-Kyoto tumor cells were studied during chemotherapy with paclitaxel, a widely used antimicrotubule agent. To visualize the microviscosity of the membranes, fluorescence lifetime imaging microscopy (FLIM) with a BODIPY 2 fluorescent molecular rotor was used. The lipid profile of the membranes was assessed using time-of-flight secondary ion mass spectrometry ToF-SIMS. A significant, steady-state decrease in the microviscosity of membranes, both in cell monolayers and in tumor spheroids, was revealed after the treatment. Mass spectrometry showed an increase in the unsaturated fatty acid content in treated cell membranes, which may explain, at least partially, their low microviscosity. These results indicate the involvement of membrane microviscosity in the response of tumor cells to paclitaxel treatment.
    Matched MeSH terms: Viscosity
  3. Maqsood K, Ali A, Ilyas SU, Garg S, Danish M, Abdulrahman A, et al.
    Chemosphere, 2022 Jan;286(Pt 2):131690.
    PMID: 34352553 DOI: 10.1016/j.chemosphere.2021.131690
    The experimental determination of thermophysical properties of nanofluid (NF) is time-consuming and costly, leading to the use of soft computing methods such as response surface methodology (RSM) and artificial neural network (ANN) to estimate these properties. The present study involves modelling and optimization of thermal conductivity and viscosity of NF, which comprises multi-walled carbon nanotubes (MWCNTs) and thermal oil. The modelling is performed to predict the thermal conductivity and viscosity of NF by using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Both models were tested and validated, which showed promising results. In addition, a detailed optimization study was conducted to investigate the optimum thermal conductivity and viscosity by varying temperature and NF weight per cent. Four case studies were explored using different objective functions based on NF application in various industries. The first case study aimed to maximize thermal conductivity (0.15985 W/m oC) while minimizing viscosity (0.03501 Pa s) obtained at 57.86 °C and 0.85 NF wt%. The goal of the second case study was to minimize thermal conductivity (0.13949 W/m °C) and viscosity (0.02526 Pa s) obtained at 55.88 °C and 0.15 NF wt%. The third case study targeted maximizing thermal conductivity (0.15797 W/m °C) and viscosity (0.07611 Pa s), and the optimum temperature and NF wt% were 30.64 °C and 0.0.85,' respectively. The last case study explored the minimum thermal conductivity (0.13735) and maximum viscosity (0.05263 Pa s) obtained at 30.64 °C and 0.15 NF wt%.
    Matched MeSH terms: Viscosity
  4. Low SY, Tan JY, Ban ZH, Siwayanan P
    J Oleo Sci, 2021 Aug 05;70(8):1027-1037.
    PMID: 34248098 DOI: 10.5650/jos.ess21078
    Liquid detergent has an increasing demand in North America, Western Europe, and Southeast Asia countries owing to its convenience to use and efficiency to clean. Alpha methyl ester sulfonates (α-MES), an anionic surfactant derived from palm oil based methyl ester, was reported to have lower manufacturing cost, good detergency with less dosage, excellent biodegradability, higher tolerance to hard water, and lower eco-toxicity as compared to linear alkylbenzene sulfonates (LABS). LABS was known as the workhorse of the detergent industry in the 20th century. Although palm-based α-MES was successfully used as the sole surfactant in powder detergent, there are still some unsettled technical issues related to phase stability and viscosity when using this anionic surfactant in heavy-duty laundry liquid detergent formulations. This paper will review not only the market overview of detergents, the application and performance of green surfactants in laundry detergents but also will highlight the technical issues related to the application of palm-based α-MES in laundry liquid detergent and some of the possible methods to overcome the formulation adversities.
    Matched MeSH terms: Viscosity
  5. Wsoo MA, Razak SIA, Bohari SPM, Shahir S, Salihu R, Kadir MRA, et al.
    Int J Biol Macromol, 2021 Jun 30;181:82-98.
    PMID: 33771547 DOI: 10.1016/j.ijbiomac.2021.03.108
    Vitamin D deficiency is now a global health problem; despite several drug delivery systems for carrying vitamin D due to low bioavailability and loss bioactivity. Developing a new drug delivery system to deliver vitamin D3 is a strong incentive in the current study. Hence, an implantable drug delivery system (IDDS) was developed from the electrospun cellulose acetate (CA) and ε-polycaprolactone (PCL) nanofibrous membrane, in which the core of implants consists of vitamin D3-loaded CA nanofiber (CAVD) and enclosed in a thin layer of the PCL membrane (CAVD/PCL). CA nanofibrous mat loaded with vitamin D3 at the concentrations of 6, 12, and 20% (w/w) of vitamin D3 were produced using electrospinning. The smooth and bead-free fibers with diameters ranged from 324 to 428 nm were obtained. The fiber diameters increased with an increase in vitamin D3 content. The controlled drug release profile was observed over 30-days, which fit with the zero-order model (R2 > 0.96) in the first stage. The mechanical properties of IDDS were improved. Young's modulus and tensile strength of CAVD/PCL (dry) were161 ± 14 and 13.07 ± 2.5 MPa, respectively. CA and PCL nanofibers are non-cytotoxic based on the results of the in-vitro cytotoxicity studies. This study can further broaden in-vivo study and provide a reference for developing a new IDDS to carry vitamin D3 in the future.
    Matched MeSH terms: Viscosity
  6. Krishnan S, Abd Ghani N, Aminuddin NF, Quraishi KS, Razafindramangarafara BL, Baup S, et al.
    Ultrason Sonochem, 2021 Jun;74:105576.
    PMID: 33975186 DOI: 10.1016/j.ultsonch.2021.105576
    This study investigates the potential of using small amounts of ionic liquids (IL) to enhance ultrasound-assisted extraction of lipids content from green microalgae. Three imidazolium-based ILs (butyl, octyl and dodecyl), each of them with two anions (bromide and acetate) were tested as additives. Viscosity and surface tension of the ILs aqueous mixtures were analyzed to determine the influence of ILs' anions and alkyl chain length, whereas KI dosimetry experiments were used as an indicator of radicals formation. A key finding suggests that the small addition of ILs improves the ultrasonication either by enhancing the viscosity and reducing the water surface tension, leading to a more powerful acoustic cavitation process or by increasing HO° production likely to oxidize the microalgae cells membranes, and consequently disrupting them on a more efficient manner. KI dosimetry also revealed that long ILs alkyl chain is detrimental. This experimental observation is confirmed thus strengthened as the yield of extracted lipids from green microalgae has shown an incremental trend when the IL concentration also increased. These hypotheses are currently under investigation to spot detailed impact of ILs on cavitation process.
    Matched MeSH terms: Viscosity
  7. Mohd Basri MS, Liew Min Ren B, A Talib R, Zakaria R, Kamarudin SH
    Polymers (Basel), 2021 May 14;13(10).
    PMID: 34069259 DOI: 10.3390/polym13101581
    Dry mangosteen leaves are one of the raw materials used to produce marker ink. However, research using this free and abundant resource is rather limited. The less efficient one-factor-at-a-time (OFAT) approach was mostly used in past studies on plant-based marker ink. The use of statistical analysis and the regression coefficient model (mathematical model) was considered essential in predicting the best combination of factors in formulating mangosteen leaf-based marker ink. Ideally, ink should have maximum color lightness, minimum viscosity, and fast-drying speed. The objective of this study to study the effect of glycerol and carboxymethyl cellulose (CMC) on the color lightness and viscosity of mangosteen-leaves-based marker ink. The viscosity, color lightness, and drying properties of the ink were tested, the significant effect of glycerol and CMC (responses) on ink properties was identified and the prediction model on the optimum value of the responses was developed by using response surface methodology (RSM). The microstructure of mangosteen leaves was analyzed to study the surface morphology and cell structure during dye extraction. A low amount of glycerol used was found to increase the value of color lightness. A decrease in CMC amounts resulted in low viscosity of marker ink. The optimum formulation for the ink can be achieved when the weight percents of glycerol, benzalkonium chloride, ferrous sulphate, and CMC are set at 5, 5, 1, and 3, respectively. SEM micrographs showed the greatest amount of cell wall structure collapse on samples boiled with the lowest amount of glycerol.
    Matched MeSH terms: Viscosity
  8. Zamram QAZM, Mohsin HF, Mohamad MM, Nor Hazalin NAM, Hamid KA
    Curr Drug Deliv, 2021 Apr 18.
    PMID: 33874872 DOI: 10.2174/1567201818666210419114809
    AIM: Formulating topical products for skin delivery has always been a challenge for pharmaceutical scientists to fulfil good formulation criteria. Despite the challenges, gel-based drug delivery offers some advantages such that it is non-invasive, painless, avoidance of the first-pass metabolism and has satisfactory patient compliance.

    OBJECTIVES: In this study, Chromolaena odorata gel and quercetin gel (bioactive flavonoid compound) were successfully formulated and compared with placebo and conventional wound aid gel. The chromatographic profilling was conducted to screen the presence of phytoconstituents. Subsequently, all formulated gels were subjected to physical characteristic and stability study.

    METHODS: Reverse Phase High-Performance Liquid Chromatography (RP-HPLC) of C.odorata methanolic leaves extract shows a distinct compound separation at retention time 8.4min to 34.8 min at 254nm. All gels were characterised by evaluating their rheological properties including storage modulus, loss modulus and plastic viscosity. Besides, texture analysis was performed to measure the gels' firmness, consistency, cohesiveness, and viscosity index.

    RESULTS: From the observation, C. odorata gel demonstrated better spreadability as compared to the other gels, which acquired less work and favourable to be applied onto the skin. Moreover, C. odorata gel showed no changes in organoleptic properties and proven to be stable after 30 days of accelerated stability study at 40°C ± 2°C with relative humidity (RH) of 75%± 5%.

    CONCLUSION: C. odorata gel has shown to be stable, reflecting the combination of materials used in the formulation, which did not degrade throughout the study. This work suggests the potential of this gel as a vehicle to deliver the active ingredients of C. odorata to the skin, which can be further explored as a topical application in antimicrobial wound management or other skin diseases study.

    Matched MeSH terms: Viscosity
  9. Soo YN, Tan CP, Tan PY, Khalid N, Tan TB
    J Sci Food Agric, 2021 Apr;101(6):2455-2462.
    PMID: 33034060 DOI: 10.1002/jsfa.10871
    BACKGROUND: The popularity of coffee, the second most consumed beverage in the world, contributes to the high demand for liquid non-dairy creamer (LNDC). In this study, palm olein emulsions (as LNDCs) were investigated as alternatives to the more common soybean oil-based LNDCs. LNDCs were prepared via different homogenization pressures (100-300 bar) using different types of oil (palm olein and soybean oil) and concentrations of DATEM emulsifier (5-20 g kg-1 ).

    RESULTS: Increases in homogenization pressure and emulsifier concentration were observed to have significant (P  0.05) differences between the prepared and commercial LNDCs in terms of their color, appearance, and overall acceptability.

    CONCLUSION: Shelf-stable LNDCs with qualities comparable to commercial LNDC were successfully fabricated. Valuable insights into the effects of homogenization pressure, oil type, and emulsifier concentration, as well as functionality and consumer acceptance of the LNDCs when added into black coffee, were obtained. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Viscosity
  10. Razzaq L, Mujtaba MA, Soudagar MEM, Ahmed W, Fayaz H, Bashir S, et al.
    J Environ Manage, 2021 Mar 15;282:111917.
    PMID: 33453625 DOI: 10.1016/j.jenvman.2020.111917
    This study investigated the engine performance and emission characteristics of biodiesel blends with combined Graphene oxide nanoplatelets (GNPs) and 10% v/v dimethyl carbonate (DMC) as fuel additives as well as analysed the tribological characteristics of those blends. 10% by volume DMC was mixed with 30% palm oil biodiesel blends with diesel. Three different concentrations (40, 80 and 120 ppm) of GNPs were added to these blends via the ultrasonication process to prepare the nanofuels. Sodium dodecyl sulphate (SDS) surfactant was added to improve the stability of these blends. GNPs were characterised using Scanning Electron Microscope (SEM) and Fourier Transform Infrared (FTIR), while the viscosity of nanofuels was investigated by rheometer. UV-spectrometry was used to determine the stability of these nanoplatelets. A ratio of 1:4 GNP: SDS was found to produce maximum stability in biodiesel. Performance and emissions characteristics of these nanofuels have been investigated in a four-stroke compression ignition engine. The maximum reduction in BSFC of 5.05% and the maximum BTE of 22.80% was for B30GNP40DMC10 compared to all other tested blends. A reduction in HC (25%) and CO (4.41%) were observed for B30DMC10, while a reduction in NOx of 3.65% was observed for B30GNP40DMC10. The diesel-biodiesel fuel blends with the addition of GNP exhibited a promising reduction in the average coefficient of friction 15.05%, 8.68% and 3.61% for 120, 80 and 40 ppm concentrations compared to B30. Thus, combined GNP and DMC showed excellent potential for utilisation in diesel engine operation.
    Matched MeSH terms: Viscosity
  11. Asyraf MRM, Ishak MR, Sapuan SM, Yidris N
    Polymers (Basel), 2021 Feb 19;13(4).
    PMID: 33669491 DOI: 10.3390/polym13040620
    The application of pultruded glass fiber-reinforced polymer composites (PGFRPCs) as a replacement for conventional wooden cross-arms in transmission towers is relatively new. Although numerous studies have conducted creep tests on coupon-scale PGFRPC cross-arms, none had performed creep analyses on full-scale PGFRPC cross-arms under actual working load conditions. Thus, this work proposed to study the influence of an additional bracing system on the creep responses of PGFRPC cross-arms in a 132 kV transmission tower. The creep behaviors and responses of the main members in current and braced PGFRPC cross-arm designs were compared and evaluated in a transmission tower under actual working conditions. These PGFRPC cross-arms were subjected to actual working loads mimicking the actual weight of electrical cables and insulators for a duration of 1000 h. The cross-arms were installed on a custom test rig in an open area to simulate the actual environment of tropical climate conditions. Further creep analysis was performed by using Findley and Burger models on the basis of experimental data to link instantaneous and extended (transient and viscoelastic) creep strains. The addition of braced arms to the structure reduced the total strain of a cross-arm's main member beams and improved elastic and viscous moduli. The addition of bracing arms improved the structural integrity and stiffness of the cross-arm structure. The findings of this study suggested that the use of a bracing system in cross-arm structures could prolong the structures' service life and subsequently reduce maintenance effort and cost for long-term applications in transmission towers.
    Matched MeSH terms: Viscosity
  12. Malviya R, Jha S, Fuloria NK, Subramaniyan V, Chakravarthi S, Sathasivam K, et al.
    Polymers (Basel), 2021 Feb 18;13(4).
    PMID: 33670569 DOI: 10.3390/polym13040610
    The rheological properties of tamarind seed polymer are characterized for its possible commercialization in the food and pharmaceutical industry. Seed polymer was extracted using water as a solvent and ethyl alcohol as a precipitating agent. The temperature's effect on the rheological behavior of the polymeric solution was studied. In addition to this, the temperature coefficient, viscosity, surface tension, activation energy, Gibbs free energy, Reynolds number, and entropy of fusion were calculated by using the Arrhenius, Gibbs-Helmholtz, Frenkel-Eyring, and Eotvos equations, respectively. The activation energy of the gum was found to be 20.46 ± 1.06 kJ/mol. Changes in entropy and enthalpy were found to be 23.66 ± 0.97 and -0.10 ± 0.01 kJ/mol, respectively. The calculated amount of entropy of fusion was found to be 0.88 kJ/mol. A considerable decrease in apparent viscosity and surface tension was produced when the temperature was raised. The present study concludes that the tamarind seed polymer solution is less sensitive to temperature change in comparison to Albzia lebbac gum, Ficus glumosa gum and A. marcocarpa gum. This study also concludes that the attainment of the transition state of viscous flow for tamarind seed gum is accompanied by bond breaking. The excellent physicochemical properties of tamarind seed polymers make them promising excipients for future drug formulation and make their application in the food and cosmetics industry possible.
    Matched MeSH terms: Viscosity
  13. Zainon SNM, Azmi WH
    Micromachines (Basel), 2021 Feb 11;12(2).
    PMID: 33670250 DOI: 10.3390/mi12020176
    Many studies have shown the remarkable enhancement of thermo-physical properties with the addition of a small quantity of nanoparticles into conventional fluids. However, the long-term stability of the nanofluids, which plays a significant role in enhancing these properties, is hard to achieve, thus limiting the performance of the heat transfer fluids in practical applications. The present paper attempts to highlight various approaches used by researchers in improving and evaluating the stability of thermal fluids and thoroughly explores various factors that contribute to the enhancement of the thermo-physical properties of mono, hybrid, and green nanofluids. There are various methods to maintain the stability of nanofluids, but this paper particularly focuses on the sonication process, pH modification, and the use of surfactant. In addition, the common techniques to evaluate the stability of nanofluids are undertaken by using visual observation, TEM, FESEM, XRD, zeta potential analysis, and UV-Vis spectroscopy. Prior investigations revealed that the type of nanoparticle, particle volume concentration, size and shape of particles, temperature, and base fluids highly influence the thermo-physical properties of nanofluids. In conclusion, this paper summarized the findings and strategies to enhance the stability and factors affecting the thermal conductivity and dynamic viscosity of mono and hybrid of nanofluids towards green nanofluids.
    Matched MeSH terms: Viscosity
  14. Shukri R, Alavi S, Dogan H, Shi YC
    Carbohydr Polym, 2021 Feb 01;253:117259.
    PMID: 33278941 DOI: 10.1016/j.carbpol.2020.117259
    The objectives of this study were to study the extrusion of cross-linked waxy maize starches (CLWMS) with different cross-linking levels and their function as a secondary ingredient in extruded oat flour (OF) formulations. CLWMS (18 %) and OF (82 %) were hydrated to 20 % moisture content and subjected to twin-screw extrusion at the screw speed of 350 rpm. Low cross-linking level of CLWMS (0.05 % sodium trimetaphosphate/sodium tripolyphosphate) in OF formulation increased the void fraction and reduced the breaking strength of extrudates. The low cross-linked starch was more resistant to breakdown and had a higher pasting viscosity than the unmodified starch. Higher cross-linking levels of CLWMS restricted swelling of starch granule and increased the resistant starch level of OF formulation but had very poor structural and textural properties. Varying the level of cross-linking offers an alternative way to manipulate the structural, textural and nutritional properties of extrudates in snack and cereal applications.
    Matched MeSH terms: Viscosity
  15. Sharip NS, Ariffin H, Yasim-Anuar TAT, Andou Y, Shirosaki Y, Jawaid M, et al.
    Polymers (Basel), 2021 Jan 27;13(3).
    PMID: 33513876 DOI: 10.3390/polym13030404
    The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young's modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young's modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.
    Matched MeSH terms: Viscosity
  16. Yap AU, Ong JE, Yahya NA
    J Mech Behav Biomed Mater, 2021 01;113:104120.
    PMID: 33086137 DOI: 10.1016/j.jmbbm.2020.104120
    OBJECTIVES: This study determined the effects of self-adhesive resin coatings on viscoelastic properties of highly viscous glass ionomer cements (HVGICs) using dynamic mechanical analysis.

    MATERIALS AND METHODS: The HVGICs evaluated were Zirconomer [ZR] (Shofu), Equia Forte [EQ] (GC) and Riva [RV] (SDI). Sixty specimens (12mm x 2mm x 2mm) of each material were fabricated using customized Teflon molds. After initial set, the specimens were removed from their molds, finished, measured and randomly divided into 3 groups of 20. Half the specimens in each group were left uncoated while the remaining half was covered with the respective manufacturers' resin coating. The specimens were subsequently conditioned in distilled water, artificial saliva or citric acid at 37°C for 7 days. The uncoated and coated specimens (n=10) were then subjected to dynamic mechanical testing in flexure mode at 37°C with a frequency of 0.1 to 10Hz. Storage modulus, loss modulus and loss tangent data were subjected to normality testing and statistical analysis using one-way ANOVA/Scheffe's post-hoc test and Ttest at significance level p<0.05.

    RESULTS: Mean storage modulus ranged from 1.39 ± 0.36 to 10.80 ± 0.86 GPa while mean loss modulus varied from 0.13 ± 0.03 to 0.70 ± 0.14 GPa after conditioning in the different mediums. Values for loss tangent ranged from 39.4 ± 7.75 to 213.2 ± 20.11 (x10 -3 ). Significant differences in visco-elastic properties were observed between mediums and materials. When conditioned in distilled water and artificial saliva,storage modulus was significantly improved when ZR, EQ and RV were uncoated. Significantly higher values were, however, observed with resin coating when the materials were exposed to citric acid.

    CONCLUSION: The visco-elastic properties of HVGICs were influenced by both resin coating and chemical environment.

    Matched MeSH terms: Viscosity
  17. Syed FNN, Zakaria MH, Bujang JS, Christianus A
    Int J Food Sci, 2021;2021:8825970.
    PMID: 33553420 DOI: 10.1155/2021/8825970
    Several aquatic macrophytes such as Colocasia esculenta, Eleocharis dulcis, Nelumbo nucifera, Sagittaria sagittifolia, Trapa bispinosa, and Typha angustifolia possessed carbohydrate mainly in their storage and reproductive parts. Starch morphology, total starch, and amylose content of these six freshwater plant species were determined. Their functional properties, i.e., starch crystallinity, thermal properties, and rheological behaviour were assessed. Large starch granules were in N. nucifera rhizome (>15 μm), medium-sized was N. nucifera seed (8-18 μm), while the rest of the starches were small starch granules (<8 μm). Shapes of the starch granules varied from oval and irregular with centric hilum to elongated granules with the eccentric hilum. Eleocharis dulcis corm starch had significantly higher total starch content (90.87%), followed by corms of C. esculenta (82.35%) and S. sagittifolia (71.71%). Nelumbo nucifera seed starch had significantly higher amylose content (71.45%), followed by T. angustifolia pollen (36.47%). In comparison, the waxy starch was in N. nucifera rhizome (7.63%), T. bispinosa seed (8.83%), C. esculenta corm (10.61%), and T. angustifolia rhizome (13.51%). Higher resistant starch was observed mostly in rhizomes of N. nucifera (39.34%)>T. angustifolia (37.19%) and corm parts of E. dulcis (37.41%)>S. sagittifolia (35.09%) compared to seed and pollen starches. The XRD profiles of macrophytes starches displayed in all the corms and N. nucifera seed had A-type crystallinity. The T. bispinosa seed had CA-type, whereas the rest of the starches exhibited CB-type crystallinity. Waxy starches of C. esculenta corm had higher relative crystallinity (36.91%) and viscosity (46.2 mPa s) than regular starches. Based on thermal properties, high-amylose of N. nucifera seed and T. angustifolia pollen resulted in higher gelatinization enthalpy (19.93 and 18.66 J g-1, respectively). Starch properties showed equally good potential as commercial starches in starch-based food production based on their starch properties and functionality.
    Matched MeSH terms: Viscosity
  18. Mat Noor NA, Shafie S, Admon MA
    PLoS One, 2021;16(5):e0250402.
    PMID: 33956793 DOI: 10.1371/journal.pone.0250402
    The heat and mass transfer on time dependent hydrodynamic squeeze flow of Jeffrey nanofluid across two plates over permeable medium in the slip condition with heat generation/absorption, thermal radiation and chemical reaction are investigated. The impacts of Brownian motion and thermophoresis is examined in the Buongiorno's nanofluid model. Conversion of the governing partial differential equations to the ordinary differential equations is conducted via similarity transformation. The dimensionless equations are solved by imposing numerical method of Keller-box. The outputs are compared with previous reported works in the journals for the validation of the present outputs and found in proper agreement. The behavior of velocity, temperature, and nanoparticles concentration profiles by varying the pertinent parameters are examined. Findings portray that the acceleration of the velocity profile and the wall shear stress is due to the squeezing of plates. Furthermore, the velocity, temperature and concentration profile decline with boost in Hartmann number and ratio of relaxation to retardation times. It is discovered that the rate of heat transfer and temperature profile increase when viscous dissipation, thermophoresis and heat source/sink rises. In contrast, the increment of thermal radiation reduces the temperature and enhances the heat transfer rate. Besides, the mass transfer rate decelerates for increasing Brownian motion in nanofluid, while it elevates when chemical reaction and thermophoresis increases.
    Matched MeSH terms: Viscosity
  19. Toopkanloo SP, Tan TB, Abas F, Azam M, Nehdi IA, Tan CP
    Molecules, 2020 Dec 11;25(24).
    PMID: 33322600 DOI: 10.3390/molecules25245873
    In order to improve the membrane lipophilicity and the affinity towards the environment of lipid bilayers, squalene (SQ) could be conjugated to phospholipids in the formation of liposomes. The effect of membrane composition and concentrations on the degradation of liposomes prepared via the extrusion method was investigated. Liposomes were prepared using a mixture of SQ, cholesterol (CH) and Tween80 (TW80). Based on the optimal conditions, liposome batches were prepared in the absence and presence of SQ. Their physicochemical and stability behavior were evaluated as a function of liposome constituent. From the optimization study, the liposomal formulation containing 5% (w/w) mixed soy lecithin (ML), 0.5% (w/w) SQ, 0.3% (w/w) CH and 0.75% (w/w) TW80 had optimal physicochemical properties and displayed a unilamellar structure. Liposome prepared using the optimal formulation had a low particle size (158.31 ± 2.96 nm) and acceptable %increase in the particle size (15.09% ± 3.76%) and %trolox equivalent antioxidant capacity (%TEAC) loss (35.69% ± 0.72%) against UV light treatment (280-320 nm) for 6 h. The interesting outcome of this research was the association of naturally occurring substance SQ for size reduction without the extra input of energy or mechanical procedures, and improvement of vesicle stability and antioxidant activity of ML-based liposome. This study also demonstrated that the presence of SQ in the membrane might increase the acyl chain dynamics and decrease the viscosity of the dispersion, thereby limiting long-term stability of the liposome.
    Matched MeSH terms: Viscosity
  20. Umar S, Sulaiman F, Abdullah N, Mohamad SN
    J Nanosci Nanotechnol, 2020 12 01;20(12):7569-7576.
    PMID: 32711628 DOI: 10.1166/jnn.2020.18616
    Conventional thermal fluids with suspended nanoparticles, known as nanofluids, have been developed for heat transfer applications. Heat transfer loss could be reduced significantly if the thermophysical properties of the heat transfer fluid are improved, which to some extent, could reduce the present global environmental challenges associated with energy utilization, such as climate change and global warming. In this work, the role of the concentration of sodium dodecyl-benzene sulfonate (SDBS) in the stability of Al₂O₃/bio-oil nanofluid is investigated the zeta potential value, and its implications to the viscosity and thermal conductivity of the nanofluid are explored. The bio-oil based nanofluid is fixed using a two-step method in which the prepared base fluid is added with 13-nm alumina nanoparticles powder. Various weight fractions of SDBS (0.1, 0.2, 0.4, 0.6, and 1.0 wt%) are used for both 0.1 and 0.2 wt% Al₂O₃ to investigate the significance of the stability of a nanofluid on its thermal conductivity and viscosity. Results indicate that a stable nanofluid has reduced viscosity and increased thermal conductivity.
    Matched MeSH terms: Viscosity
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