Degree Of Degradation Research Articles

Study on the process of mass transfer and deterioration of limestone under dynamic dissolution of CO2 solution

The long-term erosion of rock by solution can induce a series of karst problems. Therefore, this study focused on limestone and conducted dynamic dissolution experiments under deionized water and CO2 solution conditions to study the deterioration mechanism of limestone under nonequilibrium conditions. The results showed that the degree of degradation of the mechanical properties of the samples in a CO2 solution was obviously greater. In a deionized water environment, the degradation of the mechanical properties of the sample is mainly controlled by the physical softening action of the solution. In the CO2 solution environment, the degradation process can be divided into two stages. In the early stage of the experiment (10 days to 20 days), the degradation of mechanical properties of the sample is also controlled by the physical softening action of the solution. With increasing soaking time, the main rock-forming minerals of limestone gradually react with the CO2 solution, the degradation of the sample is controlled mainly by the chemical corrosion of the CO2 solution, and its degradation rate is much greater than that of physical softening. The results can be used as a reference for assessing the long-term stability of underground engineering in limestone karst development areas.

Characterization of accelerated hydrolysis degradation of poly (lactic acid) in phosphate buffered saline solution

For the reliable use of polylactic acid (PLA) materials in the human body for supportive implants, an appropriate accelerated testing method to assess the lifetime of the PLA with an acceptable model that can describe the entire degradation process is required. In this study, accelerated degradation were conducted on the polylactic acid (PLA) exposed to the phosphate buffered saline (PBS) solution at elevated temperatures, 50 ℃, 60 ℃, and 70 ℃. The high level of accelerated degradation was achieved with elevating temperatures. The evolution of surface degradation degree with exposure time was quantified by measuring the molecular end group and modeled by a proper equation. In addition, it was demonstrated that hydrolysis-induced chain-scission is the governing mechanism in the accelerated degradation. The chemi-crystallization behavior with the hydrolysis degradation was also characterized. The morphological observation revealed that the microcracks and pits are pronouncing mechanisms of surface damage. The tensile properties were severely degraded after a certain period of induction time, depending on the temperature. The sorption kinetics were also assessed and explained during the entire lifetime until the severe mass loss, based on the diffusion with degradation behavior, as well as the evolution of the morphological damages. The formation of the surface degradation layer and subsequent damages are suspected to result in early saturation and secondary sorption behavior at the elevated temperature. Finally, the integrated correlations between the sorption behavior, amount of hydrolysis degradation, and mechanical property decrease were physically described, and accurate correspondences were obtained.

GEOGRAPHICAL FACTORS OF REVITALIZATION OF RURAL SETTLEMENTS “WITHOUT POPULATION

The article proposes a method for identifying “reviving” rural settlements (RS). Case studies of the Tver region RS revealed what features of the geographical location determine a settlement opportunities for revitalization. The previous typology, based on the analysis of satellite images, showed a considerable differentiation in the degree of RS degradation, classified according to the 2010 census as “without population”. Further work to determine the leading factors of revitalization was based on the study of those RS where the houses and outbuildings, identified by satellite images, have been preserved to the greatest extent. Nearness to rivers and water bodies, position relative to federal and regional highways, and location near the regional and/or district center were chosen as key features of the geographical location that have an effect on the prospects for revitalization of a territory. The presence of registered residents (according to current records) and demarcated cadastral plots are indicators of the RS revitalization. The study showed that one third of all RS, which fell into the category “without population” according to 2010 statistics, could now be considered “reviving”. A key factor in the revitalization of rural settlements of the Tver region is their nearness to the river, mainly to the Volga River. Another important factor is the location in the zone of influence of main centers, primarily the city of Tver. The main function is the recreational (dacha) use of such villages.

Component Analysis of Corncob After Hydrothermal Treatment

Hydrothermal pretreatment is a green pretreatment technology, which can effectively promote the degradation of biomass without adding any chemical reagent. In this study, hydrothermal pretreatment on improving digestibility of corncobs was investigated and the effect of hydrothermal pretreatment on changes of structure of the corncob lignocellulose was investigated. The composition and amounts of sugar content in hydrolysate and enzymatic hydrolysate were determined. Hydrothermal treatment destroyed the lignocellulose structure of corncob and caused different degrees of degradation. With the increasing temperature of hydrothermal treatment, the degradation of cellulose, hemicellulose and lignin in corncob was detected with increasing the content of reducing sugars in hydrolysate. The hydrolysate of corncob treated by hydrothermal treatment at 190 °C for 60 min mainly included glucose, xylobiose, xylotriose and xylotetraose. The content of glucose, xylobiose, xylotriose and xylotetraose in the hydrolysate of hydrothermal treatment corncob was at level of 0.001 mg • g−1, 16.740 mg • g−1, 4.306 mg • g−1 and 3.164 mg • g−1 respectively. The yield of glucose, xylobiose, xylotriose and xylotetraose in enzymatic hydrolysate were 4.771 mg • g−1, 64.437 mg • g−1, 6.853 mg • g−1 and 1.835 mg • g−1, respectively. The understanding will help to improve the conversion and utilization of corncob as an agriculture residue.

Flexible and twistable free-standing PDMS-magnetic-nanoparticle-based soft magnetic films with robust magnetic properties

In this paper, we develop multifunctional, physically soft, mechanically compliant, and magnetically responsive PDMS films, with embedded Fe3O4 nanoparticles, that show robust magnetic properties over a significant range of mechanical deformation. First, we establish that the magnetic properties, namely the saturation magnetization (M s), remanent magnetization (M r), and intrinsic coercivity (H ci) of these PDMS films in highly deformed configurations, i.e. in folded, twisted (with different twist angles), and bent (flexed) configurations, show very little degradation compared to those obtained in undeformed configurations. Next, the films were subjected to repetitive cycles of zero-to-max deformation (R = 0) and the saturation magnetization of the films was shown to not exhibit any significant degree of progressive degradation as a function of cyclic deformation history. These findings confirm the excellent robustness and cyclic durability of magnetic properties shown by these magnetic and compliant PDMS films and point to their suitability for wearable electronics applications.

Transmission Electronic Microscopy of Vibrio cholerae Biofilms on Chitin-Containing Substrates

Introduction. The evolutionary association of Vibrio cholerae with chitin provided resistance to stress and protection from predators. The most important mechanism that provided V. cholerae with the effectiveness of association with chitin is biofilm formation. The ability to form a biofilm in V. cholerae depends on the presence of a factor, toxin-corrected adhesion pili (TCP), which are synthesized by the tcp A-F genes. One of the key methods for studying biofilms is microscopy. It allows one to visualize the structural elements and study various parameters of biofilms and the effects of various factors on them. Aim. To determine the epidemiological significance of the biofilm-forming ability of toxigenic strains by their morphological characteristics on chitin-containing substrates. Study of structural differences in biofilms of Vibrio cholerae tcpA+– and tcpA– strains on chitin-containing substrates. Results. It has been shown that Vibrio cholerae tcpA+– and tcpA– strains are able to form biofilms on the surface of chitin-containing substrates. The intensity of biofilm formation is more pronounced in tcpA+ strains, because V. cholerae ctxA+ tcpA+ cells in the biofilm are predominantly singly located and the surface of the chitinous exoskeleton with which they are in contact is intact, V. cholerae ctxA– tcpA– cells form chains in the biofilm, which indicates division processes, and scattered chitin of the endocuticle indicates activity of metabolic processes. Conclusion. The strains of V. cholerae used in the work, regardless of the presence or absence of the ctx and tcp genes, form bioplecs on a chitin substrate. The indicator of biofilm formation in terms of the thickness of the biofilm matrix is higher in V. cholerae ctxA+ tcpA+ , in terms of the degree of degradation of the chitin substrate it is higher in V. cholerae ctxA– tcpA– .

Grassland degradation amplifies the negative effect of nitrogen enrichment on soil microbial community stability.

Although nitrogen (N) enrichment is known to threaten the temporal stability of aboveground net primary productivity, it remains unclear how it alters that of belowground microbial abundance and whether its impact can be regulated by grassland degradation. Using data from N enrichment experiments at temperate grasslands with no, moderate, severe, and extreme degradation degrees, we quantified the temporal stability of soil microbial abundance (hereafter 'microbial community stability') using the ratio of the mean quantitative PCR to its standard deviation over 4 years. Both bacterial and fungal community stability sharply decreased when N input exceeded 30 g N m-2 year-1 in non-degraded grasslands, whereas a reduction in this threshold occurred in degraded grasslands. Microbial species diversity, species asynchrony, and species associations jointly altered microbial community stability. Interestingly, the linkages between plant and microbial community stability were strengthened in degraded grasslands, suggesting that plants and soil microbes might depend on each other to keep stable communities in harsh environments. Our findings highlighted the importance of grassland degradation in regulating the responses of microbial community stability to N enrichment and provided experimental evidence for understanding the relationships between plant and microbial community stability.

Effect of the anode material, applied current and reactor configuration on the atenolol toxicity during an electrooxidation process

Atenolol (ATL) is a beta-blocker pharmaceutical product which is excreted mainly unchanged and may represent a long-term risk for organisms present in the sea and in fresh water. Due to its low biodegradation rate, electrochemical advanced oxidation processes (EAOPs) can be used to remove this compound. In this work, ATL ecotoxicity was analyzed in the presence of sodium sulfate (Na2SO4), which is widely used as supporting electrolyte in EAOPs. Ecotoxicity values were expressed as the pollutant concentration that leads to a 50% inhibition of the root elongation of Lactuca sativa seeds in relation to the control (EC50(5 days)). The obtained values for ATL showed an EC50(5 days) of 1377 mg L−1 towards Lactuca sativa. When Na2SO4 was added, the toxicity of the sample increased but no synergy was detected between both compounds. With 2 g L−1 Na2SO4, ATL showed an EC50(5 days) of 972 mg L−1; and with 4 g L−1 Na2SO4 and higher concentrations, EC50 value for ATL was 0 mg L−1. Statistical tools were used to obtain the zones of the [ATL]-[Na2SO4] plane which are toxic towards Lactuca sativa.Solutions containing ATL and Na2SO4 were treated by electrooxidation. Two anode materials (a boron-doped diamond electrode and a microporous Sb-doped SnO2 ceramic one); three operation currents (0.4, 0.6 and 1 A); and two reactor configurations (one-compartment reactor and two-compartment reactor separated by a cation exchange membrane) were used. Lactuca sativa seeds and Vibrio fischeri bacterium tests were employed to evaluate the toxicity of the solutions before and after applying the electrooxidation process. In all the tests, the ecotoxicity of the treated sample increased. This fact is owing to the persulfate presence in the solution due to the sulfate electrochemical oxidation. Nevertheless, none of the final samples were toxic towards Vibrio fischeri because ecotoxicity values were lower than 10 TU; and, in the case of the one-compartment reactor, practically all of them were also non-toxic towards Lactuca sativa. The toxicity of the treated samples increased when using the two-compartment reactor in the presence of the BDD anode, and when the operation current was increased. This is attributed to the highest formation of persulfates. Amongst all the tests performed in this work, the lowest toxicity value (i.e., 3 TU) together with the complete mineralization and degradation degrees was achieved with the two-compartment reactor using the BDD anode and operating at 0.6 A.

Evaluation of the Evolution of the Ecological Security of Oases in Arid Regions and Its Driving Forces: A Case Study of Ejina Oasis in China

Ecological security is an important guarantee of human security and survival, closely related to sustainable development. However, the ecological security evaluation and driving force analysis of oases in arid areas is still insufficient. Ejina Oasis’s ecological security has experienced significant shifts following the centralized management of the Heihe River’s water allocation. Understanding the shifts in ecological security in the Ejina region is paramount for the oasis’s long-term sustainability. This paper employed the Pressure–State–Response (P–S–R) model to select socioeconomic and ecological indicators, establish a comprehensive ecological security evaluation index system, and then analyze the evolving ecological security in the region. Additionally, this paper explored the relationship between changes in the water area, oasis area, and ecological security by using the gray correlation degree to quantify the influence of Land Use Changes (LUCCs) on the overall ecological security. From 2000 to 2012, the ecological security index of Ejina Oasis remained relatively stable at around 0.4. However, a noticeable upward trend in the ecological security index emerged from 2012 to 2020, indicating a shift toward improved ecological security in the region. Critical determinants of this change included the habitat degradation degree, total population, habitat quality, carbon stock, fractional vegetation cover (FVC), the proportion of tertiary industry, and the volume of water discharged from Wolf Heart Mountain. The degree of habitat degradation, fractional vegetation cover (FVC), and the proportion of tertiary industry had the greatest impact on the change in ecological security. The pressure index was dominant in influencing ecological security before 2012 but gradually transitioned to the state index. This study offers a valuable framework for assessing the intricate relationship between LUCCs and ecological security in water-scarce, arid-region oases.

Vertical variations of bacteriohopanepolyols near the Changjiang Estuary waters: Implications for marine hypoxia and bacterial activities

Bacteriohopanepolyols (BHPs) are widespread in bacteria and are used as lipid biomarkers for specific bacterial activities and environmental changes. However, deposition and degradation dynamics of BHPs are still poorly constrained in marine settings, thereby affecting their reliability as biomarkers. Here, we investigated BHPs in the water columns and sediments near the Changjiang Estuary to evaluate their origins, preservation and responses to seawater hypoxia and bacterial activities. Results indicated that bacteriohopanetetrol stereoisomer (BHT-isomer) in this area was predominantly BHT-x produced by Ca. Scalindua, present in hypoxic bottom seawater. 2-Methyl BHT and nitrogen-fixing cyanobacteria showed similar vertical distribution in the water column, as did amnio-BHPs (aminotetrol and aminopentol) and the aerobic methane oxidation (AMO) gene pmoA. 2-Methyl BHT, aminotetrol and aminopentol were thought to primarily derive from cyanobacteria and aerobic methanotrophs in seawater, respectively, despite other potential sources. Depth profiles suggest that in-situ production in sediments is not a major contribution to sedimentary BHPs, compared to the export and deposition from the water column. The abundances of unsaturated BHT and amino-BHPs in surface sediments were decreased compared with those in the water column, indicating that unsaturated BHT and amino-BHPs appear to undergo a certain degree of early diagenetic degradation. BHT-isomer and 2-Methyl BHT preserved preferentially over amino-BHPs. Additionally, BHT-isomer significantly correlated with anammox functional gene amx-16S rRNA, and 2-Methyl BHT significantly correlated with nitrogen-fixing functional gene nifH. This indicated that BHT-isomer and 2-Methyl BHT are suitable as biomarkers for anammox and cyanobacterial nitrogen fixation. The BHT-isomer ratio accurately reflects the situation in the water column and appears to be a very appropriate proxy for hypoxia. Conversely, sedimentary aminotetrol and aminopentol underestimate the importance of aerobic methane oxidation in seawater, as these are more rapidly degraded upon deposition to the sea floor.

Boosting Noise Reduction Effect via Unsupervised Fine-Tuning Strategy

Over the last decade, supervised denoising models, trained on extensive datasets, have exhibited remarkable performance in image denoising, owing to their superior denoising effects. However, these models exhibit limited flexibility and manifest varying degrees of degradation in noise reduction capability when applied in practical scenarios, particularly when the noise distribution of a given noisy image deviates from that of the training images. To tackle this problem, we put forward a two-stage denoising model that is actualized by attaching an unsupervised fine-tuning phase after a supervised denoising model processes the input noisy image and secures a denoised image (regarded as a preprocessed image). More specifically, in the first stage we replace the convolution block adopted by the U-shaped network framework (utilized in the deep image prior method) with the Transformer module, and the resultant model is referred to as a U-Transformer. The U-Transformer model is trained to preprocess the input noisy images using noisy images and their labels. As for the second stage, we condense the supervised U-Transformer model into a simplified version, incorporating only one Transformer module with fewer parameters. Additionally, we shift its training mode to unsupervised training, following a similar approach as employed in the deep image prior method. This stage aims to further eliminate minor residual noise and artifacts present in the preprocessed image, resulting in clearer and more realistic output images. Experimental results illustrate that the proposed method achieves significant noise reduction in both synthetic and real images, surpassing state-of-the-art methods. This superiority stems from the supervised model’s ability to rapidly process given noisy images, while the unsupervised model leverages its flexibility to generate a fine-tuned network, enhancing noise reduction capability. Moreover, with support from the supervised model providing higher-quality preprocessed images, the proposed unsupervised fine-tuning model requires fewer parameters, facilitating rapid training and convergence, resulting in overall high execution efficiency.

Pruning Quantized Unsupervised Meta-Learning DegradingNet Solution for Industrial Equipment and Semiconductor Process Anomaly Detection and Prediction

Machine- and deep-learning methods are used for industrial applications in prognostics and health management (PHM) for semiconductor processing and equipment anomaly detection to achieve proactive equipment maintenance and prevent process interruptions or equipment downtime. This study proposes a Pruning Quantized Unsupervised Meta-learning DegradingNet Solution (PQUM-DNS) for the fast training and retraining of new equipment or processes with limited data for anomaly detection and the prediction of various equipment and process conditions. This study utilizes real data from a factory chiller host motor, the Paderborn current and vibration open dataset, and the SECOM semiconductor open dataset to conduct experimental simulations, calculate the average value, and obtain the results. Compared to conventional deep autoencoders, PQUM-DNS reduces the average data volume required for rapid training and retraining by about 75% with similar AUC. The average RMSE of the predictive degradation degree is 0.037 for Holt–Winters, and the model size is reduced by about 60% through pruning and quantization which can be realized by edge devices, such as Raspberry Pi. This makes the proposed PQUM-DNS very suitable for intelligent equipment management and maintenance in industrial applications.

Constant damage inelastic permanent period shift ratios spectra

The phenomenon of elongation of the structural period after earthquake excitation has been widely observed, and elongated period obtained after earthquake excitations can be used for post-earthquake assessment. The inelastic permanent period shift ratio, an indicator representing the degree of stiffness degradation and closely relating to the damage state, is defined as the ratio of the elongated period Tin of single-degree-of-freedom (SDOF) systems after earthquake excitations to the initial period Tel. The objective of this paper is to investigate the inelastic permanent period shift ratios under constant damage performances through nonlinear time-history analysis of SDOF systems, and the modified Park-Ang damage index is employed to characterize the structural damage. Inelastic permanent period shift ratio spectra are statistically constructed considering both the ground motion characteristics (such as site conditions, velocity pulse, magnitude, closet distance, directivity effects, significant duration and frequency contents) and structural parameters (including damage states, hysteretic models, ultimate deformation capacity, energy dissipation factor and postyield ratio). The results showed that the permanent period shift ratio is a reliable damage indicator for assessment of global damage states. The influence caused by ground motions on the estimation of the mean of the permanent period elongation ratio under constant damage performances is limited, while the effects caused by different structural damage and deformation capacity can reach up to approximately 70% and 33%, respectively. An expression for the relationship between the damage index and the permanent period shift ratio is established. Ignoring the differences of structural performances, using the period shift ratios to directly assess the global damage states will lead to erroneous results.

Automatic Feature Construction-Based Genetic Programming for Degraded Image Classification

Accurately classifying degraded images is a challenging task that relies on domain expertise to devise effective image processing techniques for various levels of degradation. Genetic Programming (GP) has been proven to be an excellent approach for solving image classification tasks. However, the program structures designed in current GP-based methods are not effective in classifying images with quality degradation. During the iterative process of GP algorithms, the high similarity between individuals often results in convergence to local optima, hindering the discovery of the best solutions. Moreover, the varied degrees of image quality degradation often lead to overfitting in the solutions derived by GP. Therefore, this research introduces an innovative program structure, distinct from the traditional program structure, which automates the creation of new features by transmitting information learned across multiple nodes, thus improving GP individual ability in constructing discriminative features. An accompanying evolution strategy addresses high similarity among GP individuals by retaining promising ones, thereby refining the algorithm’s development of more effective GP solutions. To counter the potential overfitting issue of the best GP individual, a multi-generational individual ensemble strategy is proposed, focusing on constructing an ensemble GP individual with an enhanced generalization capability. The new method evaluates performance in original, blurry, low contrast, noisy, and occlusion scenarios for six different types of datasets. It compares with a multitude of effective methods. The results show that the new method achieves better classification performance on degraded images compared with the comparative methods.

Experimental study on dredged slurry treatment with straw as horizonal drains by vacuum preloading

This paper presents a novel method of treating high water content dredged slurry by vacuum pre-pressure using woven rice straw as horizontal drainage boards (SHDs). This not only helps to avoid the impact of plastic drainage boards on the environment, but also helps to utilize agricultural related waste. The study aimed to investigate the effect of SHDs degradation on the vacuum transfer within the horizontal drainage boards and the consolidation characteristics of dredged slurry. Indoor vacuum preloading model tests were conducted to investigate soil settlement, straw degradation, vacuum variation and water content distribution within the drainage board. The results show that SHDs can significantly improve the consolidation of dredged slurry. The closer the straw is to the interface between the drainage board and the vacuum pipe, the greater the degree of degradation. The water content was distributed with depth in an oblique “z” shape, while a point with higher water content existed at 1/3 of the soil above the drainage boards. In addition, the low water content zone around the drainage board shows an elliptical shape due to the influence of gravity. These research results have some reference value for the ecological treatment of dredged slurry and straw.

Monitoring of oil distribution transformer in laboratory conditions

The paper discusses the issue of analyzing the amount of gas and water contained in transformer oil. Such diagnostics include tests and measurements to verify the insulating and cooling properties of the oil, from which it is possible to determine the degree of transformer degradation. The experimental measurement is mainly focused on the state of the quantity of gases and water on the oil distribution transformer and their mutual ratios using monitoring and off-line measurements. In conclusion, an example of the analysis of the mechanical strength of the winding in the oil container of the aforementioned distribution transformer is the monitoring method of tracking the cooling curves through optical sensors.

The Characteristics of Ancient Residence Wood from the Qing Dynasty in Yunnan Province

This study takes the wooden components of the different parts of the ancient buildings at the site of the Zhuangzishang Conference as the object of study, and investigates the deterioration state of the different wood components. To assess their degree of degradation, the wood anatomy, basic density (BD), maximum water content (MWC), cell wall major components, X-ray diffraction (XRD), infrared spectroscopy (IR), and thermogravimetry (TG) were used to compare the samples of new and old wood from the same species. The window (W) was identified by microscopic characterization as cypress (Cupressus sp.), the footing beam (FB) and the weatherboard (WB) as pine (Pinus spp.), the purlin (P) and the column (C) as Chinses fir (Cunninghamia spp.), and the floor (F) as spruce (Picea sp.). In terms of their physical properties, the old wood had a lower basic density of 2.58%–38.19%, a lower air-dry density of 2.87%–39.81%, and a higher maximum moisture content of 8.52%–41.38% compared to the reference wood. The degradation of the FB, which has been subjected to moisture and sunlight, and the P, which has been subjected to termite damage, was greater than that of their conspecifics. The integrated holocellulose of the ancient wood was 3.34%–16.48% less, and the hemicellulose was 1.6%–21.92% less compared to that of the reference wood, and the lignin was 1.32%–25.07% more. The XRD results showed that the crystallinity of the cellulose was greater in the different species of ancient wood compared to the control wood, which was caused by the decrease in the amorphous zones of the hemicellulose and cellulose in the ancient wood. The IR indicated that the degradation of cellulose and hemicellulose occurred in the old wood of all species, from the new lignin uptake peaks in the UV-exposed W, FB, and WB compared to the control timber. The pyrolytic behavior of the ancient and control timber is mainly related to the degradation of the tree species and the ancient wood holocellulose. These results show that the differences in the wooden components of the different parts of the ancient buildings at the Zhuangzishang Conference site are mainly related to the species of trees used in the components, and are secondly related to the location of the ancient wood members, which provides useful information for the protection and repair of the ancient buildings at the site.

Evaluation method for insulation degradation of power transformer windings based on incomplete internet of things sensing data

AbstractThis paper proposes a novel evaluation method to address the challenge of evaluating insulation degradation in power transformer windings based on incomplete online Internet of Things (IoT) sensing data. The method leverages the Wasserstein Slim Generative Adversarial Imputation Network with Gradient Penalty algorithm to fill the irregularly missing power transformer IoT perception data, including voltage, current, temperature, and partial discharge. Subsequently, electrical, thermal, and mechanical performance degradation damage indicators for transformer winding insulation are constructed using the filled and complete IoT perception data. By applying the tensor fusion algorithm, the characteristics of these degradation damage indicators are fused, leading to the development of a comprehensive degradation evaluation index for the winding insulation. The evaluation of the winding insulation degradation state is achieved through the minimum quantization error method. The proposed method is validated using the real‐world transformer IoT perception data, and the experimental results demonstrate its ability to accurately assess the degree of winding insulation degradation, regardless of the presence of random or continuous irregularities in IoT sensing data.

Improving the quality properties of soybean oil by using rice bran oil.

This study aims to study the effect of substituting soybean oil (SO) with rice bran oil (RBO) at different levels (25%, 50%, and 75%) on the physical and chemical properties, fatty acid composition, and oxidative stability of SO, also, study the effect of storing SO, RBO, and their blend oils at ambient temperature for a period of 12 months on the content of free fatty acids (% FFA), peroxide value (PV), and thiobarbituric acid (TBA). RBO demonstrated good quality, as evidenced by its initial low values of % FFA, PV, and TBA. Furthermore, RBO was found to be an excellent source of γ-oryzanol, whereas the other oils lacked this compound. Consequently, increasing the proportion of RBO in SO resulted in the least degradation, while pure SO exhibited the highest degree of degradation. Moreover, the blend oils demonstrated an inhibitory effect against oxidation, allowing for a prolonged storage period without the use of industrial antioxidants. Throughout the entire storage period, the % FFA and PV of all tested blend oil samples remained within the limits recommended for human consumption. TBA exhibited a similar trend to PV. However, an incremental increase in TBA values was observed as the storage period of the oils extended. In SO, TBA levels increased from 0.533 mg malonaldehyde/kg oil at the beginning to 1.446 mg malonaldehyde/kg oil after 12 months of storage. In RBO, TBA levels increased from 0.336 mg malonaldehyde/kg oil at the beginning to 0.882 mg malonaldehyde/kg oil after 12 months of storage.

Effects of composition and pH on the degradation of hyaluronate and carboxymethyl cellulose gels and release of nanocrystalline silver.

Adhesions are fibrous tissue connections which are a common complication of surgical procedures and may be prevented by protecting tissue surfaces and reducing inflammation. The combination of biodegradable polymers and nanocrystalline silver can be used to create an anti-inflammatory gel to be applied during surgery. In this study, sodium hyaluronate and sodium carboxymethyl cellulose were added in concentrations from 0.25% to 1% w/v to aqueous nanocrystalline silver solutions to create viscous gels. Gels were loaded into dialysis cassettes and placed in PBS for 3 days. pH was adjusted using potassium phosphate monobasic and sodium hydroxide. Release of silver into the PBS was measured at several time points. Polymer degradation was compared by measuring the viscosity of the gels before and after the experiment. Gels lost up to 84% of initial viscosity over 3 days and released between 24% and 41% of the added silver. Gels with higher initial viscosity did not have a greater degree of degradation, as measured by percent viscosity reduction, but still resulted in a higher final viscosity. Silver release was not significantly impacted by pH or composition, but still varied between experimental groups.