Normal Environmental Conditions Research Articles

Manipulation-Compliant Artificial Potential Field and Deep Q-Network: Large Ships Path Planning Based on Deep Reinforcement Learning and Artificial Potential Field

Enhancing the path planning capabilities of ships is crucial for ensuring navigation safety, saving time, and reducing energy consumption in complex maritime environments. Traditional methods, reliant on static algorithms and singular models, are frequently limited by the physical constraints of ships, such as turning radius, and struggle to adapt to the maritime environment’s variability and emergencies. The development of reinforcement learning has introduced new methods and perspectives to path planning by addressing complex environments, achieving multi-objective optimization, and enhancing autonomous learning and adaptability, significantly improving the performance and application scope. In this study, we introduce a two-stage path planning approach for large ships named MAPF–DQN, combining Manipulation-Compliant Artificial Potential Field (MAPF) with Deep Q-Network (DQN). In the first stage, we improve the reward function in DQN by integrating the artificial potential field method and use a time-varying greedy algorithm to search for paths. In the second stage, we use the nonlinear Nomoto model for path smoothing to enhance maneuverability. To validate the performance and effectiveness of the algorithm, we conducted extensive experiments using the model of “Yupeng” ship. Case studies and experimental results demonstrate that the MAPF–DQN algorithm can find paths that closely match the actual trajectory under normal environmental conditions and U-shaped obstacles. In summary, the MAPF–DQN algorithm not only enhances the efficiency of path planning for large ships, but also finds relatively safe and maneuverable routes, which are of great significance for maritime activities.

Thermodynamic performances of a novel multi-mode solar-thermal-assisted liquid carbon dioxide energy storage system

Liquid carbon dioxide energy storage is an efficient and environmentally friendly emerging technology with significant potential for integration with renewable energy sources. However, the heat recovery and utilization during compression and expansion are not implemented well. This paper proposes a multi-mode solar-thermal-assisted liquid carbon dioxide energy storage system integrated with the organic Rankine cycle. Three operation modes of normal operation mode, heat distribution operation mode, and solar thermal power generation mode are developed to achieve flexible control of the system under both normal and extreme environmental conditions. Thermodynamic performance analysis of the system under normal operation mode shows that compared to traditional system with energy storage density of 8.55 kWh/m3, the overall efficiency of the coupled system increases from 49.5 % to 62.1 %, with an energy storage density reaching 21.74 kWh/m3. The impact of key parameters such as temperature and pressure on system performance is discussed. Furthermore, an analysis of the heat flow distribution ratio under the heat distribution mode was conducted, indicating optimal system performance at a heat flow ratio of 6:4. Comparative analysis of the system performance under various operating conditions for the three operation modes was performed, elucidating the operational strategies of each mode.

Management of toxic waste released by incorrectly discarded batteries in Brazil

Abstract The main difference between a dry cell battery and an alkaline one is the composition of the electrolyte. In zinc–carbon batteries, dry cell, the electrolyte is a paste formed by mixing ammonium chloride and zinc chloride, whereas in alkaline batteries, the electrolyte is a concentrated aqueous solution of potassium hydroxide containing a certain amount of zinc oxide, hence the name alkaline for this battery. Therefore, the improper disposal of these materials has numerous consequences for the environment, since the potentially toxic metals present in them can be leached, infiltrating, and contaminating the soil layers, the groundwater, as well as the fauna and flora of the regions nearby. Thus, the objective is to perform studies that aim to simulate and analyze the release of potentially toxic metals present in batteries found in normal environmental conditions, through leaching tests from regular batteries (Zn–C) on fertilized soil, simulating a landfill, in addition to tests on sandy soil in order to aid the identification of possible waste release.

Phytoremediation potential of Brassica oleracea varieties through cadmium tolerance gene expression analysis

BackgroundBrassica oleracea var. acephala, commonly referred to as kale, is a well-documented plant species, a food crop but well recognized for its capacity to endure and manage the accumulation of heavy metals. In this research, the phytoremediation potential of kale was evaluated based on cadmium intake, utilizing three distinct kale varieties originating from Bosnia and Herzegovina. All kales were grown in controlled conditions, with different concentrations of cadmium (Cd), a known strong pollutant found in small concentrations in soil under normal environmental conditions. After the root length analysis and cadmium atomic spectrometry, we utilized quantitative PCR (qPCR) and cycle threshold (Ct) values to calculate the expression levels of five genes associated with Cd heavy metal response: Mitogen-activated protein kinase 2 (MAPK2), Farnesylated protein 26 and 27 (HIPP26, HIPP27), Natural resistance-associated macrophage protein 6 (RAMP6), and Heavy metal accumulator 2 (HMA2). ResultsThe atomic reader's analysis of rising cadmium concentrations revealed a proportional decline in the length of kale roots. The gene expression levels corresponded to cadmium stress differently among varieties, but mostly showing notable up-regulations under Cd stress, indicating the strong Cd presence within the plant. ConclusionsThis study demonstrated differences in gene expression behavior among three B. oleracea varieties from Bosnia and Herzegovina, indicating and filtering the Cd-resistant kale, and kale varieties suitable for phytoremediation. For the first time, such a study was conducted on kale varieties from Bosnia and Herzegovina, analyzing the impact of cadmium on the growth and resilience of these species.

Dynamic response analysis of a semisubmersible floating offshore wind turbine subjected to mooring line failure under normal and extreme environmental conditions

Floating offshore wind turbines (FOWTs) offer a significant opportunity for harnessing wind energy and achieving clean energy goals. This paper investigates the effects of mooring line failure in semisubmersible FOWTs under normal and extreme environmental conditions. The OC4 DeepCwind type semisubmersible with an NREL 5 MW wind turbine is considered for investigating the behavior of FOWT under intact and failed mooring lines. This study covers a wide range of environmental conditions, operational conditions of wind turbines, and mooring line failure scenarios. This paper investigates the mooring line failure effects on platform responses, mooring line fairlead tensions, and tower responses. The results show that the platform surge, heave, pitch responses, tower fore-aft displacement, base shear force in X-direction, and base moment in Y-direction are increased for upwind side mooring line failure during the operational condition of FOWT. Subsequently, the platform sway, roll, yaw responses, tower side-to-side displacement, base shear force in Y-direction, and base moment in X-direction are more during downwind side mooring line failure in the same environment. On the other hand, the impact of upwind side mooring line failure affects all 6 Degrees of Freedom (DOF) platform responses significantly during the parked state of FOWT. The maximum fairlead tensions observed in the remaining mooring lines remain below the mooring line breaking strength even after a mooring line failure during both operational and parked states of FOWT. It is also observed that the platform responses (excluding heave), tower responses, and fairlead tensions exhibit greater values when an extreme turbulence wind model is employed. The platform surge, heave, pitch responses, maximum fairlead tension, tower fore-aft displacement, and tower base moment in Y-direction show higher values under severe sea state condition.

Efficacy ofhydroxypropyl-guar dropsin improving tear film index and ocular surface dynamicsusing two treatment methods under a controlled desiccating environment.

This study aimed to assess the efficacy of hp-guar eye drops on tear film index and ocular surface dynamics under desiccating conditions using protection and relief treatment modalities. The 12 normal, non-dry eye participants were subjected to adverse environmental conditions using a Controlled Environment Chamber (CEC) where the relative humidity (RH) was 5% and the ambient temperature was 21°C. The participants were screened for ocular symptoms, tear osmolarity, ocular surface temperature (OST), tear production using the Ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620, and Schirmer strips. Tear production was calculated by the Tear Function Index test (TFI). The mean tear film osmolarity decreased significantly from 296mOsm/L at 40% RH to 285mOsm/L at 5% RH (p = 0.01). Conflicting responses were seen for osmolarity in protection and relief. Mean tear osmolarity was significantly higher in the protection method in comparison to the relief method (p = 0.005). The mean TFI increased from 557 at 40% to 854 at 5% (p = 0.02). A significant increase in TFI was observed in the relief method in comparison with both 40% (p = 0.001) and 5% (p = 0.04). In the relief method, the mean TFI score went up to 1139 when hp-guar was installed. A significant improvement in ocular comfort was experienced in both the protection (p = 0.041) and relief (p = 0.010) methods at 5% RH. The instillation of hp-guar drops in the relief method resulted in a significant reduction in OST. The mean OST dropped to 33.01 ºC, significantly lower than the recorded OST for both normal (p = 0.040) and dry (p = 0.014) environmental conditions. Hp-guar drops significantly improve tear film parameters under a desiccating environment, however, tear film parameters respond differently to the management modalities. In the protection method, tear film osmolarity was protected against a dry environment, while in the relief mode, an improvement in tear production and a decrease in ocular surface temperature were seen. Hp-guar performance could be maximized for the management of exposure to adverse environments by using a treatment protocol that targets the most affected parameters in each group of patients. Using CEC has the potential to provide researchers with a readily available method to evaluate the efficiency of tear supplementation.

Parametric investigation of battery thermal management system with phase change material, metal foam, and fins; utilizing CFD and ANN models

The focus on developing an effective battery thermal management system (BTMS) to maintain optimal temperatures for lithium-ion batteries (LIBs), especially in electric vehicle (EV) applications, has grown significantly. The effective BTMS not only enhances the cooling performance of LIBs but also contributes to increased passenger safety and mileage of EVs. This study investigates BTMS configurations with fins, metal foam, and phase change material (PCM) to minimize temperature of battery during 3C discharging in varying conditions. Additionally, the study explores the impact of different BTMS material combinations and various fins lengths on system performance as a parametric investigation. Moreover, to streamline the analysis process and introduce novelty, artificial intelligence is explored as an alternative to computational fluid dynamics for predicting liquid fraction of PCM and temperature of battery, enhancing the innovative aspect of this study. Numerical simulations, using a non-equilibrium thermal model for metal foam modeling, reveal that the fourth case, integrating all three passive approaches, maintains the lowest temperature and enhances LIB cooling. The optimum BTMS shows a reduction of 3 K compared to BTMS utilizing pure PCM. During discharge process, the temperature difference in the battery decreases by approximately 75 % and 66 % in the fourth case compared to the first case (with pure PCM) under normal and harsh environmental conditions, respectively. Applying copper metal foam and copper fins yields the best results in reducing battery temperature. Increasing the length of fins and adding more fins effectively lower the battery temperature. Finally, an artificial neural network model is developed using the backpropagation learning technique coupled with the gradient descent optimization algorithm. The model exhibits excellent predictive capabilities, achieving high R-squared values of 0.98 for PCM liquid fraction and 0.99 for battery temperature.

Feasibility of micro-organisms in soil bioremediation and dust control

Detrimental impacts of dust caused by mine tailings have yielded to several studies on the efficiency of different soil stabilizers. Bacterial stabilization has been recognized as a reality within recent decades, where bacteria could get adhesion to the grains and stabilize the soil particles. However, these bacteria are prone to be destroyed while exposed to the normal environmental conditions. In this study, the effects of microcapsules containing two types of bacterial freeze-dried spores (B.Subtilis Natto LMG 19457 and B.ESH) have been investigated on the mine tailing stability in terms of two parts. The first part of the study is dedicated to the fabrication of microcapsules within the two bacteria and identification of the characteristics of these microcapsules to set the time of microcapsules break and release in the soil. The urea-formaldehyde microcapsules containing tung oil were synthesized using microencapsulation method and at the following, the bacterial spores of B.Subtilis Natto LMG 19457 and B.ESH which had the high durability and the capability to grow in the silicon oil, were added to the microcapsules. The microcapsules effect on MT specimens and the viability of encapsulated spores were determined. The characteristics of the capsules were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric thermal analysis (TGA). In the second part, wind tunnel tests were conducted to study the effects of microorganism stabilizers on mine tailings. The results indicated that the dust erosion reduced from 16% - using water as a stabilizer- to the 0.2% while using microcapsules containing B.Subtilis Natto LMG 19457 and 0.8% while using microcapsules containing ESH. The results showed the high efficiency of microcapsules containing bacteria in stabilizing the MTs. This phenomenon was proved by SEM imaging in which the voids were bounded significantly while using the bacteria.

Performance Of Concrete-To-Concrete Bond Strength in Wetland Area

One of the techniques of building rehabilitation methods is repairing. Repair is a rehabilitation process to restore the initial capacity of damaged structures on structural components. A fairly popular repair technique is concrete-to-concrete. The strength of this bonding depends on several factors. The mixture used to repair the material affects the bond strength, as does the surface treatment and curing conditions. The study analysedanalysed the influence of strong bonds on surface treatment and curing conditions. Surface preparations were performed with four methods: as cast, drill holes, grooving, and bonding agent. The curing cycle applied two conditions: normal and wet-dry, and the test objects were compressive strength tests, slant shear tests, tensile tests, and flexural tests. The study results showed that the influence of wet-dry environmental conditions was lower than normal environmental conditions, and the highest bond strength values were found in grooving treatments, drill holes, as cast and bonding agents.

The reversible piezochromic luminescence behavior of carbon dots under a cycle of loading/unloading pressure.

Carbon dots (CDs) have gained intensive interest owing to their small size, unique structure, excellent photoluminescence (PL) properties and broad applications. In particular, pressure-triggered irreversible piezochromic behavior of fluorescent CDs was previously reported and attributed to the sp2-sp3 transition in the carbon core or aggregation-induced emission under high pressure. Here, we report the reversible piezochromic behavior of microwave-heating synthesized CDs (named M-CDs) using ethylenediamine and aspartic acid as precursors. Under a loading/unloading cycle, the PL intensity of M-CDs decreased continuously with the pressure increasing from 101 kPa up to 20 GPa, and the maximum emission of M-CDs at 101 kPa (λmax = 550 nm) was slightly blue-shifted to 541 nm at 20 GPa, but when the pressure was released from 20 GPa to normal environmental conditions, both the emission wavelength and the PL intensity of M-CDs returned to their initial states at 101 kPa. The control sample was also synthesized using the same precursors but through a hydrothermal method and thus named H-CDs. Both H-CDs and M-CDs have similar particle sizes, morphology and excitation-dependent PL behavior under 101 kPa; however, H-CDs showed a typical piezochromic behavior with the emission blue-shifted from 518 to 491 nm when the pressure was increased from 101 kPa to 0.97 GPa, and then red-shifted from 491 to 530 nm when the pressure was increased up to 10.53 GPa. This irreversible behavior of H-CDs was accompanied by a 2-fold enhancement of their PL intensity after releasing the pressure. The remarkable different behaviors of M-CDs and H-CDs under a loading/unloading cycle are caused by different interior structures of M-CDs and H-CDs due to different synthetic processes, which is worthy of further research.

Highly Efficient and Reliable Organic Light–Emitting Diodes Enabled by a Multifunctional Hazy Substrate for Extreme Environments

AbstractAs transparent, flexible, and wearable organic electronics degrade under normal outdoor environmental conditions (e.g., water vapor, oxygen, and UV light) and extreme environments, including washing or rain, a customized encapsulation technology is required to improve device reliability. Herein, a simple process is presented for fabricating multifunctional hazy substrates (MFHSs) with excellent gas diffusion barrier (GDB), flexibility, UV reflectance, light scattering, and waterproof properties. First, a spiky polyethylene terephthalate (PET) surface is produced with 76.0% optical haze through ion‐beam treatment followed by the formation of a hydrophobic layer to achieve a waterproof effect (contact angle: 153.3°). Then, a multifunctional multibarrier film is fabricated based on a nano‐laminated distributed Bragg reflector and functional polymer on the functional PET substrate to serve as a GDB and UV filter. This multibarrier film has excellent mechanical and chemical stabilities, in addition to having a water vapor transmission rate of 10−6 g m−2 day−1 and UV transmittance of <3%. The so‐fabricated MFHS not only increases the device efficiency by 73% but also enables a highly flexible and environmentally stable organic light–emitting diode. The surface treatment and encapsulation technologies developed in this study are expected to increase the lifetime of organic devices and facilitate high outdoor usability.

Increasing Sensitivity and Selectivity for Heavy Metal Sensing through Microfluidic Electrochemical Sensor

Introduction Cadmium usually exists in nature as a compound and under normal environmental conditions, its small content will not affect human health. Nevertheless, with human society's development, heavy metal ions pollution has become substantially serious, and they have serious biological toxicity. Hence, it is important to develop simple, rapid, sensitive, and portable devices for Cd2+ sensing [1].In the present work, we show how paper based microfluidic sensors improve sensitivity and limit of detection (LOD) in comparison to classical screen-printed carbon-based electrode (SPCE). Furthermore, the presented microfluidic electrochemical carbon-based sensor (μCS) do not employ critical metals and rely on graphite foil that is modified by N-doped carbon nanoonions (N-CNOs) N-CNOs. Experimental For the synthesis of N-doped CNOs the Kuznetsov method was employed [2]. The alignment of the component for μCS device is sketched below. After providing the analyte solution through the sponge the electrochemical detection is carried out through accumulation of the metal at the working electrode for varying times and cathodic potentials. The final detection is carried out through square wave anodic stripping voltammetry (SWASV) of the accumulated metal. Results and discussion To realize a sensitive measurement, some experimental conditions including the optimal amount of the employed N-doped CNOs and Nafion in the nanocomposite, deposition time and potential, and the effect of pH of supporting electrolyte were studied. By increasing the deposition time ranging from 0 to 5 min, the SPCE/N-CNOs signal was increased and after that, it remains roughly constant because the WE surface is being saturated and also the amount of analyte in the droplet was reduced due to the presence of a stagnant flow. However, for μCS/N-CNOs by increasing the accumulation time ranging from 0 to 10 min the signal was increased which shows that the electrode surface is still far from being saturated (because of the live flow). A linear concentration range from 1.0 to 100.0 μg L- 1 was achieved using SWASV. Also, the LOD and sensitivity are calculated to be 0.5 μg L- 1 and 1.02 μA µM-1 cm-2, respectively. Additionally, the method was successfully employed for measurements of Cd2+ in different real samples, which demonstrated the excellent applicability of the device for the adsorption and detection of heavy metal ions. Conclusion The μCS/N-CNOs offers several core advantages over SPCE/N-CNOs in terms of cost, simplicity, analysis time, and sensitivity. These unique advantages are due to the combined microfluidic configuration, 3D electrode layout, and a unique modifier. We believe our findings would have significant implications in developing other portable, fast, and cost-effective electrochemical detection platforms, such as clinical diagnosis and security inspection.

Development of local-power-free, remote α-particle detection using optical fibers.

We demonstrate the application of fluorescence optical fiber coupled to a telecom grade fiber as a sensor for alpha particles using alpha-specific ZnS(Ag) scintillation materials whose wavelength is down-shifted into a low-loss region of the telecom grade fiber transmission band. Telecom-grade fiber optics offer a solution for sensing alpha radiation in deep repositories and cask storage for radioactive materials due to the stability of SiO2 under normal environmental conditions and its relative radiation hardness at low radiation doses. Long-term nuclear waste storage facilities require sensors for the detection of leakage of radioactive materials that are maintenance-free, do not require power and can survive with no 'wear out' mechanisms for decades. By accomplishing the wavelength transformation, we maximize efficiencies in the detection of α-particles and signal transport and can detect alpha scintillation at distances on the order of >1km with a sensor that is ~3% efficient and can be easily scaled as a sensor array. This paper describes the construction and testing of the sensor including manufacture of the controlled thickness films, verification of the wavelength shift from 450to 620nm and optimization of the sensitivity as a function of thickness. We also model the relative sensitivity of the film as a function of film thickness, and we demonstrate a signal-to-noise ratio of 10 at a range of greater than 1km.

Evaluation of the Groundwater Ecological Water Requirement in the Southeast Margin of Otindag Sandy Land Based on Allowable Groundwater Depth Drawdown

Water resources in arid and semi-arid areas are limiting factors for ecosystem health and economic development. Therefore, an accurate and reasonable assessment of ecological water demand is crucial for efficient water resource utilization. In this study, we used vegetation coverage and groundwater depth to assess the state of vegetation growth in the Zhenglanqi, located at the southeastern edge of Otindag Sandy Land. Our results indicate the existence of a statistical power index function between vegetation coverage and groundwater depth scatter plots, where even minor changes in groundwater depth can have a significant impact on vegetation growth. In order to quantitatively assess the impact of subsidence on vegetation ecology, we propose a maximum allowable subsidence level under conditions that maintain normal ecological conditions, based on the initial subsidence depth and ecological guarantee rate. Our findings suggest that regions with shallower initial groundwater depths are more sensitive to changes in their environment than regions with deeper groundwater depths. The total groundwater consumption in the study area was 83 million cubic meters while maintaining an ecological guarantee rate of 80%; thus, while ensuring normal environmental conditions, human exploitation of shallow groundwater accounts for only 16 percent.

Sustainable green composite of yam and agricultural waste corn stalk fiber with good mechanical, thermal, optical, aging performance and excellent biodegradability

Sustainable green composites with safe biodegradability produced using environmentally benign materials are required as modern-day alternatives for harmful synthetic materials. Agricultural waste such as corn stalks and underutilized natural polymer sources such as yam are significant potential candidates in this regard. In our work, a green composite of yam and alkali-treated corn stalk fiber was prepared through a simple solution casting and oven-drying method. The successfully prepared green composites displayed good mechanical and thermal properties as the corn stalk fibers effectively reinforced the yam bioplastic matrix. Spectral studies such as FTIR, SEM, and p-XRD confirmed the probable structural changes and formation of the composites. Prepared green composites possessed high resistance and good thermal (−2 °C and 70 °C), UV (254 nm for 180 hours), and chemical aging properties along with low moisture absorption behavior. Further, the green composites showed excellent biodegradable nature under normal environmental conditions. Thus, potentially capable green composite for applications in packaging, biomedical, automobile, and construction sectors was reported here.

Effect of heat shock on embryonic development and its impact on commercial traits of silkworm Bombyx mori. L

The early stage of an organism – embryonic stage, architects all the post embryonic developments which are governed by genetic and environmental conditions, but the effect of hot events during that stage remain obscure in the silkworm Bombyx mori L. Thus, APM1; a multivoltine parental breed of a ruling CB and APHO1 silkworm breed developed through induction of thermotolerance, and APHO1 breed to examine the impact of heat shock (HS) on the embryo and resulta nt larvae. Different developmental stages of embryo were exposed to varied HS temperatures for 2 h followed by a 2 h recovery period. After HS the eggs and the resultant larvae were reared under normal environmental conditions. Interestingly, 450C although determined as lethal temperature yielded vibrant larvae. Whereas APM1 and APHO1 eggs heat shocked at 350C exhibited increased hatching (91.66 and 69.33%), larval weight (1.72 and 3.33 g), effective rate of rearing (72.39 and 81.93%), cocoon weight (1.01 and1.6 g), shell weight (0.12 and 0.29 g), shell ratio (13.11 and 20.52%) and pupal weights (0.87 and1.29g) when compared to control APM1 and APHO1. Besides increased total protein content, expression of 205 kDa, 90 kDa and 70 kDa heat shock proteins and the glycogen content was found more on day - 3 compared to day - 2 in the embryos of APM1 and APHO1 which eventually declined as the embryonic development proceeded to hatching. This work shows that APM1 and APHO1 eggs had shown profound response to HS temperatures exhibiting varied acquired thermotolerance to overcome fluctuating environmental condition.

Identifying indigenous bast microfibers for archaeological research in East Asia

East Asia, particularly China, has a long history of fiber production. Before cotton was introduced in historic times, bast fibers from various indigenous plants dominated fiber technologies. Previous studies on early fiber technology primarily relied on indirect evidence because actual fiber and textile remains are extremely rare in archaeological contexts. Such materials tend to decay quickly in normal environmental conditions, a situation that negatively impacts on our knowledge of the origin and diversity of fiber technology in the past. However, archaeologists have often observed microfiber remains when conducting microfossil analysis (such as starch and phytoliths) on artifact residues and soils, indicating a great potential for the study of ancient fibers from archaeological contexts. In this study, we first analyze morphological features of five modern bast fibers indigenous to East Asia, including hemp, ramie, kudzu vine, velvet leaf, and paper mulberry, to create a reference database; then we discuss the applicability of these features to identification of archaeological microfiber remains.

Utilization of Extraction Procedures for Evaluating Environmental Risk from Waste Materials.

Several procedures for extracting content from different waste materials types were investigated, with the aim of evaluating their environmental impact. The waste materials consisted of wastes from bauxite ore processing by means of the Bayer process (red mud, Ajka, Hungary), bauxite ore using the sintering process followed by the Bayer process (brown-red mud, Žiar nad Hronom, Banská Bystrica region, Slovakia) and sulphide ores (metal-rich post-flotation tailing, Lintich, Slovakia). The extraction procedures were carried out with the aim of isolating "mobilizable" fractions using 0.05 M ethylenediaminetetraacetic acid (EDTA) and 0.43 M acetic acid (AA) (representing environmental risk during changes in normal environmental conditions) and "maximum potentially mobilizable" fractions using 2 M HNO3 (representing the total environmental risk). The content of chosen toxic heavy metals (THMs) (Cd, Cr, Cu, Pb, Ni, Zn) and Fe, Mn as metals creating Fe/Mn oxides in the extracts and solutions after microwave digestion was determined using high-resolution continuum source flame atomic absorption spectrometry (HR CS FAAS). On the basis of the results obtained in this study, it is possible to state that different origin of waste materials is reflected in different mobility of toxic heavy metals into the surrounding environment. From the point of view of toxic heavy metals mobility, disposal site of wastes after bauxite processing are much less of a threat to the environment than disposal site of flotation sludge after processing sulphide ores. The single extraction of 0.43 M AA is more effective than the extraction of 0.05 M EDTA for the purposes of determining the content of metals in the mobilizable fraction of tailing waste materials. The mobility of the studied toxic heavy metals in the Lintich tailing decreases in the direction from the lagoon to the dam, which may indicate the fact that the dam serves to a certain extent to inhibit the mobility of metals into the surrounding ecosystem.

Quercetin-mediated alteration in photosynthetic efficiency, sugar metabolism, elemental status, yield, and redox potential in two varieties of okra.

Quercetin is a bioactive natural compound with an antioxidative property that can potentially modify plant physiology. The current investigation aimed to gauge the effect of different concentrations of foliar spray of quercetin (0, 0.5, 1, 1.5, 2.0 mM) on several morphological and physio-biochemical performances of Abelmoschus esculentus L. (Moench.) plants under normal environmental conditions. The foliar spray on the plant leaves was applied 25 days after sowing (DAS) and continued up to 30 DAS once each day. The plants were sampled at 30 and 45 DAS to monitor several parameters. The foliar treatments of quercetin significantly upgraded all the studied parameters. The results direct that most of the traits such as growth, nutrient uptake, photosynthetic, and enzyme activities were promoted in a dose-dependent way. Quercetin application lowered the reactive oxygen species (ROS) buildup by increasing the antioxidant enzyme activities. Microscopic investigations further revealed a significant enhancement in the stomatal aperture under quercetin application. Out of several doses tested, 1 mM of quercetin proved best and can be used for further investigations.

Evaluation of Therapeutic Capability of Emustil Drops against Tear Film Complications under Dry Environmental Conditions in Healthy Individuals.

Background and Objectives: Dry eye disease (DED) is a multifactorial ailment of the tears and ocular surface. The purpose of this study was to assess the tear film physiology under controlled dry environmental conditions and compare the efficacy of oil-in-water emulsion drops on tear film parameters in protection and relief treatment modalities under low-humidity conditions. Emustil eye drops were used after exposure to a low-humidity environment in the relief method, whereas, in the protection method, the drops were applied before exposure to low humidity. Materials and Methods: 12 normal male subjects (mean age 34.0 ± 7.0 years) were exposed to ultra-dry environmental conditions. A number of tear film measurements were carried out under desiccating environmental conditions in a controlled environment chamber (CEC), where the chamber temperature sat at 21 °C with a relative humidity (RH) of 5%. Keeler's TearScope Plus and an HIRCAL grid were used to assess the tear break-up time and lipid layer thickness (LLT), and the evaporation rate was evaluated using a Servomed EP3 Evaporimeter. Results: LLT measurements showed that the dry environment affected LLT significantly (p = 0.031). The median grade of LLT dropped from grade 3 (50-70 nm) at 40% RH to grade 2 (13-50 nm) at 5% RH. A significant increase in LLT was seen after both modes of treatment, with a median LLT grade of 3 when the Emustil was used for both protection (p = 0.004) and relief (p = 0.016). The mean tear evaporation rate in normal environmental conditions (40%) was 40.46 ± 11.80 g/m2/h (0.11 µL/min) and increased sharply to 83.77 ± 20.37 g/m2/h (0.25 µL/min) after exposure to the dry environment. A minimal decrease in tear film evaporation rate was seen in relief; however, statistical tests showed that the decrease in tear film evaporation rate was not significant. Mean NITBUT dropped from 13.6 s at 40% RH to 6.6 s at 5% RH (p = 0.002). All NITBUT measurements at 5% RH (with or without the instillation of Emustil) were significantly lower than those at 40%. The instillation of Emustil at 5% RH resulted in a significant improvement in NITBUT for protection (p = 0.016) but this was not the case for relief (p = 0.0.56). Conclusions: A control environmental chamber (CEC) enables the analysis of tear film parameters comparable to those found in dry eye patients. This enables us to examine the capability of oil in emulsion drops to manage tear film disruption in healthy individuals. This study suggests that using Emustil oil-in-water emulsion before exposure to a dry environment should be advocated for people who work in dry environments.