TSI Values Research Articles

Numerical investigation on the impact of aerodynamic braking plates positioned at streamlined sections on the slipstream and wake flow of the high-speed train based on train-fixed reference frame

This paper studies the aerodynamic characteristics of high-speed trains (HSTs) featuring aerodynamic braking plates installed on the streamlined sections, employing the improved delayed detached eddy simulation (IDDES) method at Re = 5.0 × 105. The precision of the numerical simulation methodology has been validated through reduced-scale wind tunnel experiments. A comparative analysis has been conducted on the characteristics of slipstream, wake flow, and upper flow between the original configuration (OC) and the braking configuration (BC) of the HSTs. The findings reveal that the application of braking plates promotes significant separation phenomena around the HSTs, enhancing the slipstream velocity distribution. In the BC, compared to the OC, the maximum value of the time-averaged slipstream velocity has increased by approximately 134.9% and 76.8% at the trackside and platform positions, respectively. Additionally, the TSI value of the slipstream velocity shows increases of around 100.4% and 210.4% at the trackside and platform positions, respectively. Meanwhile, the turbulence fluctuations within the wake region have been enhanced, with the formation of a longitudinal vortex alongside the railway subgrade, whose core nearly covers the TSI positions. Notably, obvious shifts occur within the upper flow field, which significantly strengthens both flow turbulence and slipstream velocity, potentially influencing components on the upper surface of HSTs, such as the pantograph. The deployment of braking plates contributes to a significant increase in overall vehicle pressure drag, thereby enhancing the train's aerodynamic drag. Relative to the OC, the aerodynamic drag of the HST has increased by approximately 235.4% in the BC.

Carboxymethyl chitosan/polyvinyl alcohol hydrogel films by incorporating MSNs as ε-PL carrier with pH-responsive controlled release and antibacterial properties

A hydrogel film with pH-responsive release and excellent antibacterial properties was developed by utilizing mesoporous silica nanoparticles (MSNs) as carriers for ε-PL. Carboxymethyl chitosan (CMCS) is grafted onto aminated-MSNs through amine-bond reaction mediated, which is subsequently bound to polyvinyl alcohol (PVA) by esterification reaction. The addition of MSNs and optimization of CMCS proportion improved the dispersion stability of CMCS/PVA, resulting in a TSI value of 0.6 for 1.6CMCS/0.8PVA@MSNs-ε-PL, which is significantly lower than other groups. The proportion increase of CMCS improved the thermal stability and water oxygen barrier capacities of the 1.6CMCS/0.8PVA@MSNs-ε-PL by enhancing cross-linking with MSNs. The 1.6CMCS/0.8PVA@MSNs-ε-PL exhibited pH-responsive release behavior, with the extent of release increasing proportionally with higher pH levels. The 1.6CMCS/0.8PVA@MSNs-ε-PL exhibited significant antibacterial activity against Pseudomonas azotoformans MN10 in vitro, attributed to the ε-PL's ability to damage the bacterial membrane structure. Hence, the 1.6CMCS/0.8PVA@MSNs-ε-PL exhibits significant potential in food preservation.

Preparation of Modified Polycarboxylate by Pyrrolidone for Using as a Dispersant in Cobalt Blue Nano-Pigment Slurry.

In this paper, N-vinylpyrrolidone was copolymerized with acrylic acid and itaconic acid by free radical polymerization, and a series of polyacrylic acid-co-itaconic acid-co-N-vinylpyrrolidone (PAIN) dispersants with different pyrrolidone ligand contents were synthesized and characterized. Then, the cobalt blue nano-pigment slurry (20 wt%) was prepared through a water-based grinding method, and the optimum grinding technology was explored and determined as follows: PAIN2 as a dispersant, a dispersant dosage of 10 wt%, and a grinding time of 480 min. According to this optimum grinding technology, the prepared pigment slurry had a significantly decreased agglomeration, the D90 of which was 82 nm, and separately increased to 130 nm and 150 nm after heat storage for 3 and 7 days, exhibiting excellent heat storage stability. Additionally, its TSI value was also the lowest (1.9%), indicating good dispersion stability. The QCM and adorption capacity measuring results showed PAIN2 had a larger adsorption capacity, and the formed adsorption layer had a higher rigidity and was not easy to fall off. This was caused by both the interaction of carboxyl groups and the pyrrolidone ligand (strong coordination interaction) in PAIN2 with cobalt blue. The XPS and FT-IR measurements further proved the above-mentioned adsorption mechanism.

Application of rheology and interfacial rheology to investigate the emulsion stability of ultrasound-assisted cross-linked myofibrillar protein: Effects of oil phase types

This work was designed to illustrate the differences in the dispersed phase that affect the emulsion stability. The effect of oil types including soy oil, corn oil, rapeseed oil, sunflower oil, and flaxseed oil on the stability of the emulsion stabilized by modified MP (sonication after crosslinking treatment) was investigated. Results showed that the differences in fatty acid composition in the oil phase would affect the interaction between the oil phase and modified MP. Emulsion in the P-flaxseed group (with higher linolenic acid) showed lower TSI values, smaller protein-coated oil droplets, higher adsorbed protein content, storage modulus, and small elastic Lissajous curve area than other emulsion groups. While the P-rapeseed (with higher oleic acid) and P-sunflower (with higher linoleic acid) groups had large droplet sizes, poor emulsion stability, and rheological behavior. Correspondingly, the higher θo/w (86.97°), hf, π (21.55 mN/m), Kdiff, KR, Ed, E-π slope (3.22), and linear interfacial Lissajous plot in the P-flaxseed group indicated modified MP was preferred to adsorb on the surface of flaxseed oil to form an elastic-dominated interfacial protein film with higher deformation resistance. Furthermore, the poorer interfacial adsorption behavior and easily collapsed interfacial film further proved the poor emulsion stability of the P-rapeseed and P-sunflower groups. Therefore, differences in fatty acid compositions of oil phases impacted the interfacial adsorption characteristics of the modified MP, thereby influencing the emulsion stability.

Preparation of Nanoemulgels Containing Lemon Essential Oil and Pectin: Physical Stability and Rheological Properties

Nanoemulgels are novel formulations of great interest for their use as dual-release systems and as fat substitutes in foods. Lemon essential oil, with a large number of benefits due to its antimicrobial, antifungal, and medicinal properties, and low methoxyl pectin, a natural polysaccharide capable of gelling by adding divalent ions such as calcium, are very appropriate ingredients to produce nanoemulgels with potential applications in industries such as cosmetics, agrochemistry, pharmaceuticals, or food. In this work, lemon-essential-oil-in-water nanoemulgels containing low methoxyl pectin derived from citrus peels were prepared following a three-step process that involves the preparation of a nanoemulsion, a pectin gel, and the mixture of both. In the first stage, the stirring time and the rotational rate employed during the mixing step were assessed. Once the preparation protocol was established, the pectin gel/nanoemulsion mass ratio was investigated. Different techniques were combined to evaluate the influence of the processing and the composition variables on the particle size distribution, mean diameters, flow curves, and physical stability of different emulgels obtained. It was found that the processing variables studied, stirring time, and rotational rate, do not influence the mean particle size of the emulgel, with values matching those of the starting nanoemulsion. However, 3 min and 200 rpm were selected for exhibiting the lowest TSI values. Regarding the composition, a higher content of pectin gel caused a higher viscosity, and therefore a higher physical stability, with the 75P/25E emulgel being the most stable. Aggregation of gel particles, because the pectin gel was really a sheared gel, was the main responsible contributor to the results obtained. This work highlights the importance of the preparation and formulation variables to develop stable, innovative formulations based on nanoemulgels.

Research on the ratio of multicomponent emulsion flooding system

In recent years, field test and industrialized application of ASP (alkaline/surfactant/polymer) flooding has been carried out in oilfields, which has obtained an obvious effect on increasing oil and decreasing water and good economic efficiency. However, due to the large proportion of alkali in the ASP flooding system, there are problems such as severe scaling and high cost during field tests, which restrict the promotion of ASP flooding. In order to reduce the amount of alkali used, achieve the goal of reducing scaling and costs, and meanwhile improve emulsification performance while maintaining interfacial activity, a multicomponent emulsion flooding system was developed by combining emulsifier HEFR2 with petroleum sulfonate and sacrificial agent LSCP1 with NaOH.Through laboratory experiments, the water extraction rate, particle diameter, Tsi value, and interfacial activity of the multicomponent emulsion flooding system were tested under different conditions. The results show that when the mass ratio of petroleum sulfonate to emulsifier HEFR2 is between 3:1 and 5:1, and the mass ratio of sacrificial agent LSCP1 to NaOH is between 3:1 and 7:1, the multicomponent emulsion flooding system can maintain good emulsification stability and interfacial activity. The multicomponent emulsion flooding system significantly reduces the amount of alkali used, and the cost of chemical agents is 11% lower than that of the ASP flooding system. At the same time, it achieves the goal of improving the stability of emulsifiers, maintains interfacial activity and reduces costs. This technology has broad application prospects.

Oil displacement performance and mechanism of Interfacially Active polymer (IAP)-Emulsifying viscosity Reducer (EVR) supramolecular compound system in heterogenous heavy oil reservoirs

Chemical Cold Heavy Oil Production (CCHOP) represents an effective approach to exploit heavy oil by injecting Oil Viscosity Reducer (OVR). However, the challenge lies in the crossflow of traditional OVR through high permeability channels in heterogeneous heavy oil reservoirs. a supramolecular compound system comprising Interfacially Active Polymer (IAP) and Emulsifying Viscosity Reducer (EVR) were proposed as a novel CHHOP agent to address this problem. A series of experiments were conducted to investigate the heavy oil displacement performance and mechanism of the IAP-EVR compound system, including assessments of heavy oil emulsification, emulsion stability, rheological properties, single-core oil displacement, and heterogeneous microscopic oil displacement. The results demonstrate that a stable O/W emulsion can be formed with the 0.1 wt% IAP-0.3 wt% EVR compound system under a low mixing rate of 200 rpm. The emulsion exhibits only an 8.0% dewatering rate and a low TSI value of 0.8. Moreover, the compound system effectively reduces the heavy oil viscosity from 1000 mPa·s to 325.7 mPa·s, facilitating the emulsification of the remaining oil after water flooding and enhancing its flowability, thus improving oil displacement efficiency. Additionally, the 0.1 wt% IAP-0.3 wt% EVR compound system increases the solution viscosity to 600 mPa·s, leading to a low W/O mobility ratio, which enhances the swept volume. Supramolecular association is identified as a crucial mechanism for stabilizing the emulsion and increasing the solution viscosity, as evidenced by a high elastic modulus of 144.7 mPa and a transition area observed in the viscosity-shear rate curve. In comparison to HPAM and IAP, the 0.1 wt% IAP-0.3 wt% EVR compound system yields higher oil recoveries of 21.84 %OOIP in the single core experiment. Moreover, noticeable emulsification is observed in the produced fluid, and oil recoveries of 89.85 %OOIP and 92.98 %OOIP are achieved in high and low permeable areas, respectively, in the heterogeneous microscopic model. These results indicate a mechanism that enhances both the swept volume and oil displacement efficiency. Overall, the findings of this study provide a laboratory foundation for the promising application of the IAP-EVR compound system in heterogeneous heavy oil reservoirs.

Index of rain aggressiveness and erosivity in different climate types in Brazil

Heavy rains are responsible for triggering erosion processes and landslides. Knowledge of the spatial variation of rainfall aggressiveness makes it possible to plan land use and propose prevention and mitigation measures. This work aims to evaluate the rainfall aggressiveness indices and relate them to the climatic types in Brazil. Estimated monthly precipitation data were used for each Brazilian municipality and the Fournier (IF), Modified Fournier (IFM) and Total Erosivity Index (TEI) indexes were calculated. The data were geoprocessed and correlated with the climate types in Brazil, according to the Köppen classification. The IF ranged from 7.3 to 110.5 with 47.5% of the territory classified as “Moderate erosivity”. The IFM ranged from 48 to 388 with 76% in the “Very High” erosivity class and 16.0% “High”. The climate types Af, Am Cfb, Cwa and Cwb are classified as “Moderate erosivity” or higher. The TSI ranged from 444 to 4977 and 54.3% had “High” erosivity and 31.5% “Moderate”. The climate type Am presented the highest mean TSI followed by Aw, Af, As, CWa and Cwb, with TSI above 2000. The lowest TSI values ​​were observed in the Cfa and Cfb climates, followed by the BSh climate.

Carrying capacity of mangrove environment for development of river cruise ecotourism in Pengudang, Bintan Island, Indonesia

Mangrove ecotourism management requires information about the ability of the ecosystem to support the presence of tourists so that environmental damage due to human activities can be minimized. This study aims to analyze the suitability of Mangrove Ecotourism for River Cruise in Pengudang Village and recommend the carrying capacity of mangrove ecosystems for ecotourism. The study was conducted using a Geographic Information System approach, data was collected through a Criteria survey for ecotourism to explore rivers and analyzed using a weighting and assessment approach. The results showed that the Pengudang mangrove ecosystem was feasible to be developed for River Cruise ecotourism with a TSI value ranging from 64-75%. Cluster 3 has the largest TSI value of 75%. This is influenced by several parameters such as the density of mangroves and the diversity of mangrove species in the area which attracts visitors to conduct tourism and educational activities. The limiting parameters in River Cruise ecotourism activities in Pengudang are the width of the river and the depth of the river which can only be passed by boats under 5 GT. The carrying capacity or ability of the mangrove ecosystem to accommodate ecological tourism reaches a maximum of 106 people/day.

Persimmon tannin can enhance the emulsifying properties of persimmon pectin via promoting the network and forming a honeycomb-structure

In the present study, multi-scale methods, including emulsifying capability evaluation and emulsion stability determination, were used to explore the effect of persimmon tannin (PT) on the emulsification performance of persimmon pectin (PP). A series of PP-PT solutions containing 10 mg/mL of PP and 0.05–2 mg/mL of PT were prepared and used to fabricate oil-in-water emulsions. Further, the potential influencing mechanism of PT on the emulsifying characteristics of PP was exploited by the Cryo-SEM morphology, interfacial tension, and interfacial dilatational rheology measurements. The results indicated that the emulsifying and emulsion-stability potential of PP was enhanced with the addition of high-level PT (1 and 2 mg/mL), reflected by the improvement in emulsifying capacity, droplet sizes (D 32 , D 43 , and particle size), TSI value, creaming thickness, and the strengthened tolerance to salt ions (100–1000 mmol/L NaCl and 100–500 mmol/L CaCl 2 ), heating treatment (50–90 °C for 60 min), and accelerated destruction process (thermal cycling and accelerated centrifugation). However, PT in low concentrations (0.05, 0.1, and 0.2 mg/mL) displayed emulsion-damaging effects. In addition, high concentrations of PT (1 and 2 mg/mL) promoted the 3D-network structure, formed the honeycomb structure of emulsions and enhanced the viscoelasticity of the interfacial film to resist unfavorable factors. In contrast, the network structure and interfacial viscoelasticity deteriorated when low levels of PT (0.05, 0.1, and 0.2 mg/mL) were added. Overall, high levels of PT can be a cooperative agent for enhancing the emulsification properties of PP. Our data might provide a scientific basis for broadening the application of PP and PT as functional ingredients in the food industry. • PT significantly affected the emulsification properties of PP. • High concentrations of PT (1 and 2 mg/mL) enhanced PP's (10 mg/mL) emulsifying performance; by contrast, the low levels (0.05, 0.1, and 0.2 mg/mL) damaged it. • High concentrations of PT (1 and 2 mg/mL) promoted the 3D-network structure, formed the honeycomb structure of emulsions and enhanced the viscoelasticity of the interfacial film to resist unfavorable factors.

A Saprobic Index for quality of Minapadi Water and the Fish Osmotic Performance Level of Minapadi

Ending hunger is one of the Sustainable Development Goals (SDG) that must be achieved to achieve prosperity. The supply of these food needs connects with human dwelling requirements. Numerous technologies have been developed to solve these difficulties. One of these technologies is minapadi, which uses land effectively. For sustainability objectives to be realized, using such technology must preserve environmental quality. This research intends to assess changes in water quality resulting from the usage of minapadi, as well as fish osmosis performance in minapadi. This research is performed to determine the effect of minapadi technology on water and fish. Samberembe Sleman is the location that has been adopting minapadi for a long time and is the Food and Agriculture Organization of the United Nations (FAO) pilot site. In order to acquire data for use in computing the Tropic Saprobity Index, the minapadi water of Samberembe was collected monthly for four months during the study. Blood samples from tilapia (Oreochromis niloticus) were collected in the fourth month to determine osmotic performance levels. The acquired findings have the highest SI value of 0.986 and the lowest SI value of 0.968. The state of β (meso/oligo saprobik) has the highest TSI value with a value of 1.011, while the state has the lowest TSI value with a value of 0.995 β (meso saprobik). Iso-hyperosmotic is the pattern of osmoregulation in tilapia (Oreochromis niloticus) in minapadi. Stable SI and TSI levels at Minapadi do not fluctuate. This result suggests that the water quality is with lightly contaminated water, yet the TSI value indicates that the water is fertile and potable. The normal condition of fish in minapadi indicates that the use of minapadi does not affect environmental conditions.

Influence of Dispersed TiO2 Nanoparticles via Steric Interaction on the Antifouling Performance of PVDF/TiO2 Composite Membranes.

Herein, the influence of various contents of polyethylene glycol (PEG) on the dispersion of TiO2 nanoparticles and the comprehensive properties of PVDF/TiO2 composite membranes via the steric hindrance interaction was systematically explored. Hydrophilic PEG was employed as a dispersing surfactant of TiO2 nanoparticles in the pre-dispersion process and as a pore-forming additive in the following membrane preparation process. The slight overlap shown in the TEM image and low TSI value (<1) of the composite casting solution indicated the effective dispersion and stabilization under the steric interaction with a PEG content of 6 wt.%. Properties such as the surface pore size, the development of finger-like structures, permeability, hydrophilicity and Zeta potential were obviously enhanced. The improved antifouling performance between the membrane surface and foulants was corroborated by less negative free energy of adhesion (about -42.87 mJ/m2), a higher interaction energy barrier (0.65 KT) and low flux declination during the filtration process. The high critical flux and low fouling rate both in winter and summer as well as the long-term running operation in A/O-MBR firmly supported the elevated antifouling performance, which implies a promising application in the municipal sewage treatment field.

Study on the Influence of Ultrasound Homogenisation on the Physical Properties of Vegan Ice Cream Mixes

This study investigated the effect of ultrasound homogenisation on the physical properties of vegan ice cream mixes. Samples were prepared based on vegan recipes with different sorts of stabilisers such as iota carrageenan and iota carrageenan’s acid and enzymatic hydrolysates. Ice cream mixes were compared for stability, particle size distribution, rheological properties and morphological structure. All mentioned analyses were conducted before and after 24 h of maturation at 4 °C. It was found that the ultrasound treatment decreased the size of particles and, in conjunction with the maturation stage, a significant reduction was visible (the lowest value was at 9.76 µm). The addition of the hydrolysates of iota carrageenan had a considerably better effect in reducing the size of particles than iota carrageenan. The range of TSI values was from 1.7 to 4.2. Additionally, two sorts of destabilisation occurred: sedimentation and coalescence, during the maturation of ice cream mixes, which was also visible in the images. According to the rheological properties, ice cream mixes, with the addition of stabilisers, showed non-Newtonian shear-thinning (pseudoplastic) behaviour. Moreover, the effect of ultrasound treatment on the consistency index was only pivotal for ice cream mixes with an addition of iota carrageenan and with enzymatic β-galactosidase hydrolysates of iota carrageenan.

A Study on the Mechanisms of Nanoparticle-Stabilized High Internal Phase Emulsions Constructed by Cross-Linking Egg White Protein Isolate with Different Transglutaminase Concentrations.

There is an increasing interest in the development of high internal phase emulsions (HIPE) stabilized by food-grade nanoparticles due to their potential applications in the food industry. In this study, cross-linked egg white protein isolates (cEPIs) are prepared by adding 10 u/g, 20 u/g, and 40 u/g of transglutaminase (TG), and the impacts of interface properties of cEPIs and emulsifying of HIPEs are investigated. Relative to the native EPI, the cEPIs have more irregular and agglomerated morphology, and the turbidity and hydrophobicity are significantly increased. The particle size and zeta potential of cEPIs considerably varied with the addition of TG. In HIPE, the formation, physical properties, and microstructure are characterized by visual observations, the Turbiscan stability index, and CLSM. The results indicated that stable and gel-like HIPEs are formed by cEPIs at oil internal phase (φ) values of 0.75–0.90. Especially for the enzyme additions of 20 u/g, the cEPIs had the best storage stability and the lowest TSI value (2.50) and formed a gel network structure at φ values of 0.9 microscopically. Overall, this study can enrich the theoretical frame of interface properties by enzyme treatment. Besides, it would be of great importance for the research of HIPE stabilized by cEPIs appropriate to be applied in food formulations.

EVALUATION OF EUTROPHICATION STATUS OF POOVAR ESTUARY, SOUTHERN KERALA, INDIA

In the present study, the Poovar estuary (PV) of southern Kerala was selected for the evaluation of eutrophication status using Carlson’s Trophic State Index (CTSI). This study is based on Secchi disk transparency- TSI(SD), the concentration of total phosphorus- TSI(TP) and chlorophyll a- TSI (Chl.a) using CTSI. The results of TSI showed that, based on TSI(SD), the PV estuary is under the eutrophic category characterised by high productivity. Season-wise values of TSI (SD) are greater (>60) than TSI(Chl.a), indicating non-algal suspended particles responsible for light attenuation as turbidity is dominated by runoff containing wastewater than algae emanating from canals adjoining the estuary. The TSI(Chl.a) is greater than TSI(TP), which indicates total phosphorus limiting the algal growth. The CTSI Index of PV estuary reveals that all sampling stations fall under the eutrophic condition.

Preparation of Nano-TiO2-Modified PVDF Membranes with Enhanced Antifouling Behaviors via Phase Inversion: Implications of Nanoparticle Dispersion Status in Casting Solutions.

Titanium dioxide (TiO2) nanoparticles have been applied in membrane antifouling performance modification for years. However, the influence of TiO2 nanoparticle dispersion status during the blending process on membrane properties and the inner mechanism has seldom been focused on. Herein, we investigated the influence of the various dispersing statuses of TiO2 nanoparticles on membrane properties and antifouling performance by exploring various blending processes without changing the original recipe. Polyethylene glycol (PEG) was employed as a pore-forming agent during the membrane preparation process, and also as a pre-dispersing agent for the TiO2 nanoparticles via the steric hindrance effect. Compared to the original preparation process of the PVDF/TiO2 composite membrane, the pre-dispersing of TiO2 via PEG ensured a modified membrane with uniform surface pores and structures on cross-sectional morphologies, larger porosity and water permeability, and more negative zeta potential. The contact angle was decreased by 6.0%, implying better hydrophilicity. The improved antifouling performance was corroborated by the increasing free energy of cohesion and adhesion, the interaction energy barrier (0.43 KT) between the membrane surfaces and approaching foulants assessed by classic XDLVO theory and the low flux decline in the filtration experiment. A kinetics mechanism analysis of the casting solutions, which found a low TSI value (<1.0), substantiated that the pre-dispersion of TiO2 with PEG contributed to the high stability and ultimately favorable antifouling behaviors. This study provides an optimized approach to the preparation of excellent nano-TiO2/polymeric composite membranes applied in the municipal sewage treatment field.

Novel antibacterial hydrogels based on gelatin/polyvinyl-alcohol and graphene oxide/silver nanoconjugates: formulation, characterization, and preliminary biocompatibility evaluation

Antibiotic resistance has become a major public health problem generated by their excessive and inappropriate use. This is worrisome because multiple microbial infections that could traditionally be treated without major complications are now considerably challenging to treat. In this regard, research in this field has been focused on searching for new molecules capable of arresting these microbial infections with high effectiveness, including antimicrobial peptides (AMP) and various nanomaterials. Here, we proposed a novel topical hydrogel treatment based on a polymeric network of gelatin-polyvinyl alcohol-hyaluronic acid encapsulating a graphene oxide (GO) nanoconjugate on which silver nanoparticles (Ag NPs) have been grown. This treatment is intended to be stable, biocompatible, non-toxic, pleasant to skin contact, provide bioavailability of the active agent for a prolonged period in the affected skin area where its application is required and inhibit microbial growth effectively. The nanocomposite hydrogels were characterized in terms of microstructure, thermal resistance, rheological behavior, particle size distribution, texture profile and physical stability, as well as a one-month accelerated stability study. The satisfactory results in terms of physical chemistry, stability on storage modulus (G’), TSI values, and microstructure allowed choosing some points of the experimental design to encapsulate the GO-Ag NPs nanoconjugates. The biological evaluation of these nanocomposites showed that the treatments are biocompatible as they have a very low hemolytic effect (less than 5%) and a moderate platelet aggregating capacity (35%–45%). Finally, 100% of bacterial growth was inhibited by the action of the topical nanocomposite hydrogel treatments. These results led to affirm that these treatments can have an excellent performance in this application as well as in wound healing and dressing, bioadhesives, tissue engineering, and other biomedical applications.

Hydrodynamic alignment and self-assembly of cationic lignin polymers made of architecturally altered monomers

Cationic kraft lignin (CKL) polymers with different degrees of grafting (35.2–125.5 mol%) were synthesized via polymerizing kraft lignin (KL) and [2-(acryloyloxy)ethyl]trimethylammonium chloride (ATAC) or [2 (methacryloyloxy)ethyl]trimethylammonium methyl sulfate (METAM) to investigate the impact of the chain extension of the polymers on the physicochemical behavior of CKL in an aqueous solution. It was observed that, at the same grafting ratio, the structural difference of CKLs influenced their hydrophilicity, in which the contact angle of KL-METAM and KL-ATAC solution (1 g/L) reached 9.4° and 11.8° on a glass slide, respectively, at the maximum degree of grafting of ~125 mol%. KL-METAM had a more three-dimensional and flexible structure than KL-ATAC in solution, which promoted its self-assembly (with the aggregate diameter of 235–532 nm) and sedimentation (with the TSI value of 16.8). The rheological studies confirmed the more elasticity of KL-METAM than KL-ATAC with the elastic modulus of 9.3 and 8 Pa at the highest frequency. Quartz crystal microbalance (QCM) adsorption studies illustrated that KL-METAM adsorbed more greatly and generated a bulkier and more viscoelastic adlayer than KL-ATAC did on a rigid surface, below saturation (ΔD/Δf slope of 0.13–0.45) and at equilibrium (ΔD/Δf slope of 0.02–0.17). For the deposited adlayer, the alterations in the slope of dissipation/frequency (ΔD/Δf) between the early and late stages of adsorption were claimed to be related to the conformational changes of CKLs upon adsorption. The findings of this study showed that the architecture of cationic monomers could affect the structure of CKLs so significantly that the lignin polymers would have different chain conformations and flexibility in solution, varied rheological properties, and adsorption performance on a solid surface. The significance of the monomer architecture on the properties and performance of CKLs was more observable at a higher grafting ratio.

Nineteen Years of Trophic State Variation in Large Lakes of the Yangtze River Delta Region Derived from MODIS Images

The Yangtze River Delta (YRD) is one of the regions with the most intensive human activities. The eutrophication of lakes in this area is becoming increasingly serious with consequent negative impacts on the water supply of the surrounding cities. But the spatial-temporal characteristics and driving factors of the trophic state of the lake in this region are still not clearly addressed. In this study, a semi-analytical algorithm for estimating the trophic index (TSI) using particle absorption at 645 nm based on MODIS images is proposed to monitor and evaluate the trophic state of 41 large lakes (larger than 10 km2) in the YRD from 2002 to 2020. The performance of the proposed algorithm is evaluated using an independent dataset. Results showed that the root-mean-square error (RMSE) of the algorithm is less than 6 and the mean absolute percentage error (MAPE) does not exceed 8%, indicating that it can be applied for remotely deriving the TSI in the YRD. The spatial-temporal patterns revealed that there were significantly more lakes with moderate eutrophication in the Lower Yangtze River (LYR) than in the Lower Huaihe River (LHR). The overall average value of the TSI reaches a maximum in summer and a minimum in winter. The TSI value in the YRD over the period 2002–2020 showed a downward trend, especially after 2013. Individually, 33 lakes showed a downward trend and 8 lakes showed an upward trend. Furthermore, marked seasonal and interannual temporal variations can be clearly observed in the LYR and LHR and the sum of the variance contributions of seasonal and interannual components is more than 50%. Multiple linear regression analysis showed that human activities can explain 65% of the variation in the lake TSI in the YRD.

Science Highlights and Final Updates from 17 Years of Total Solar Irradiance Measurements from the SOlar Radiation and Climate Experiment/Total Irradiance Monitor (SORCE/TIM)

The final version (V.19) of the total solar irradiance data from the SOlar Radiation and Climate Experiment (SORCE) Total Irradiance Monitor has been released. This version includes all calibrations updated to the end of the mission and provides irradiance data from 25 February 2003 through 25 February 2020. These final calibrations are presented along with the resulting final data products. An overview of the on-orbit operations timeline is provided as well as the associated changes in the time-dependent uncertainties. Scientific highlights from the instrument are also presented. These include the establishment of a new, lower TSI value; accuracy improvements to other TSI instruments via a new calibration facility; the lowest on-orbit noise (for high sensitivity to solar variability) of any TSI instrument; the best inherent stability of any on-orbit TSI instrument; a lengthy (17-year) measurement record benefitting from these stable, low-noise measurements; the first reported detection of a solar flare in TSI; and observations of two Venus transits and four Mercury transits.