Tank Production Research Articles

Evaluation of the Performance of Microalgae and Constructed Wetlands for the Reduction of Toxicity Organic Load and Pharmaceuticals from Wastewaters

The present study aimed to evaluate the performance of a novel integrated system composed of microalgae and constructed wetlands (CW). The microalgae production tank was designed as a raceway type, and microalgae of the genus Chlorella were inoculated, while the CW was established as the first stage of the French model and vegetated with the macrophytes Chrysopogon zizanioides, Typha domingensis, and Dracaena trifaciata. The hydraulic retention time in each unit was 7 days, totaling 14 days of treatment. Good reductions in dissolved organic carbon (67.2%) and Total N (68.6%) were achieved after the treatment. The treatment also completely eliminated acute ecotoxicity against Daphnia magna and genotoxicity in the Allium cepa test assay. Liquid chromatographic analysis revealed the presence of 9 pharmaceuticals in the raw wastewaters, whereas only residual dipyrone was detected after the CW unit. Thus, the novel system investigated in our study, which combines microalgae and CW using 3 different species of macrophytes, proved to be a promising alternative for treating urban wastewaters, as it effectively reduced organic load, nutrient content, toxicity, and removed emerging contaminants such as pharmaceuticals. Future recommendations include investigating the primary removal mechanisms of the pharmaceuticals and enhancing the separation process of the microalgae.

RESEARCH ON THE DESTRUCTION PROCESSES OF WELDED JOINTS UNDER CONDITIONS OF DETACHMENT OF THE VERTICAL STEEL TANK BODY FROM THE BOTTOM DURING A FIRE

The study presents a comprehensive analysis of welded joints by applying advanced mathematical modelling and experimental research methods. The primary objective was to develop and validate a methodology for mathematical modelling of the behaviour of welded joints under mechanical loading, as well as to assess the effectiveness of the proposed approaches in predicting their strength and durability. Based on the research results, we can draw the following conclusions. The authors obtained the results of welded joint samples and analysed the corresponding curves of the dependence of force factors on their deformations. The study showed that the destruction of welded joints occurs mainly along the weld seam, where the strength is lower than in the base material of the rods. It is consistent with the practical data of the experiment, which confirms that the weld is the weakest link in the structure. The article substantiated a set of provisions and assumptions for implementing mathematical modelling of the behaviour of samples of welded joints imitating welded joints in a reservoir for petroleum products under mechanical tensile tests. The test results justified the mathematical models of the steel material of welded joints of petroleum product tanks and obtained numerical parameters of the mechanical properties of steel of welded joints. Yield strength is in the range of 240–300 MPa, the modulus of elasticity is 190–240 GPa, the hardening modulus is 18–20 GPa, and the ultimate plastic deformation is 0.00334. Based on a complex of well-founded mathematical models of welded joints, we carried out calculations regarding the numerical study of the behaviour of welded joints under the conditions of their mechanical tests. We compared the obtained results with the results of experimental tests and, based on this comparative analysis, established that they were adequate since the Fisher criterion did not exceed the tabular value and the relative error did not surpass 12%. The findings of this research offer valuable insights and practical recommendations for improving the design and evaluation of welded structures, enhancing their performance and safety in engineering applications.

Predicting weight dispersion in seabass aquaculture using Discrete Event System simulation and Machine Learning modeling

Marine aquaculture, particularly in the Mediterranean region, faces the challenge of minimizing growth dispersion, which has a direct impact on the production cycle, market value and sustainability of the sector. Conventional grading methods are resource intensive and potentially detrimental to fish health. The current study presented an innovative approach in predicting fish weight dispersion in European seabass (Dicentrarchus labrax) aquaculture. Seabass is one of the two major fish species cultivated on the Mediterranean coast, with a fattening cycle of 18–24 months. During this period, several grading operations are carried out to minimize growth dispersion. The intricate feed-fish-water system, characterized by complex interactions among feeding regimes, fish behavior, individual metabolism and environmental factors, is the focus of the study. The comprehensive, five-step methodology addresses this complexity. The process begins with a Discrete Event System (DES) model that simulates the feed-fish-water dynamics, taking into account individual fish metabolism. This is followed by the development of a surrogate machine learning (ML) regressor model, which is trained on DES simulation data to efficiently predict growth distribution. The model is then calibrated and customized for specific fish stocks and production tanks. The preliminary results from 21 tanks in two trials with European seabass (D. labrax) showed the effectiveness of the method. The results from the simulation models achieved a R2 of 99.9 % and a Mean Absolute Percentage Error (MAPE) of 1.1 % for the prediction of mean final weight and a R2 of 90.3 % with a MAPE of 8.1 % for the standard deviation of final weight. In summary, this study represents a significant advance in the planning and management of seabass aquaculture. Given the lack of effective prediction tools in the aquaculture industry, the proposed methodology has the potential to reduce risks and inefficiencies, thus possibly optimizing aquaculture practices by increasing sustainability and profitability.

Upgrading low-concentration oxygen-bearing coal bed methane by dual-reflux vacuum swing adsorption

Fugitive methane (CH4) is a typical by-product of mining processes, which is commonly known as coal bed methane (CBM) or coal mine gas (CMG). The capture of these CH4 gases can simultaneously avoid greenhouse gas emissions and provide extra energy benefits. However, the explosion risk of low-concentration CBM (CH4 molar fraction ≤ 30%) requires strictly safe operating protocols to conduct the capture process. Dual reflux vacuum swing adsorption (DR-VSA) is a promising candidate with a vacuum operating condition which can lower the explosion risk and simultaneously reach CH4 enrichment and O2 removal targets in product and effluent streams. Herein, a low-concentration oxygen-bearing CBM (20% CH4, 16% O2 and 64% N2) can be upgraded to 69.7 mol% in the product gas while ensuring an effluent concentration of 2.5 mol% by the DR-VSA cycle using ionic liquidic zeolites (ILZ) as the adsorbents. A rigorous safety analysis has been conducted to investigate the explosion risk in the adsorption column and product tank, suggesting that the DR-VSA process is a safe technology for upgrading low-concentration oxygen-bearing methane.

Leveraging media for demand control in an optimal network of renewable microgrids with hydrogen facilities in South Korea

Abstract In pursuit of a sustainable 2030 strategy in the Republic of Korea, this study addresses the oversight in recent optimal renewable energy microgrid designs, which, despite encompassing all feasible renewable sources, neglected the pivotal role of hydrogen as an energy carrier. This research explores the feasibility of reprogramming media platforms to dynamically shape energy consumption during peak intervals. It further proposes the retrofitting of microgrids with industrial hydrogen production and storage facilities, aligning with controlled electricity demand. A comprehensive social survey investigates the impact of media content on energy-conscious behaviour and cooperation, specifically targeting energy savings during peak hours. Utilizing a probabilistic model, the study quantifies responses from the surveyed sample and decomposes the energy demand time series to reveal three new consumption patterns: demand reduction by lowering residential electricity consumption at peak intervals without shifts, intense demand shifting by redistributing electricity consumption from peaks to valleys without human intervention, and moderate demand shifting achieved through cooperation with consumers. With these novel energy demand patterns in hand, the study optimally designs renewable microgrids in 17 sites in South Korea, comparing two strategies: Plan A, involving electrolysis-based hydrogen production and storage tanks, and Plan B, which excludes hydrogen facilities. Comparative results demonstrate that media content contributes to a 10.28% and 16.11% reduction in peak electricity consumption, with and without human intervention, respectively. In Plan B, a demand cut saves 937.3 MWh/yr, resulting in a 12.88% reduction in the levelized costs of electricity (LCOE) and a 4.67% reduction in net present costs (NPC) of optimal renewable microgrids in Korea. Conversely, in Plan A, intense demand reduction exhibits superior performance, leading to $981K less NPC, 1,046 MWh/yr less excess electricity, and a 3.76% smaller LCOE. The study recommends the implementation of smart gadgets to control residential electricity consumption, producing industrial hydrogen at Korean sites based on consumer attention and agreement with specific media content. However, it underscores the importance of studying the socio-psychological effects of this plan in future research.

Bioremediation of Basil Pesto Sauce-Manufactured Wastewater by the Microalgae Chlorella vulgaris Beij. and Scenedesmus sp.

Chlorella vulgaris and Scenedesmus sp. are commonly used in wastewater treatment due to their fast growth rates and ability to tolerate a range of environmental conditions. This study explored the cultivation of Chlorella vulgaris and Scenedesmus sp. using wastewater from the food industry, particularly from Italian basil pesto production tanks. The experiment involved different carbon dioxide concentrations and light conditions with a dilution rate of basil pesto wastewater at 1:2. Both microalgae strains were able to grow on pesto wastewater, and biomass characterization highlighted the influence of CO2 supply and light irradiation. The highest lipid storage was 79.3 ± 11.4 mg gdry biomass−1 and 75.5 ± 13.3 mg gdry biomass−1 for C. vulgaris and S. obliquus under red light (5% CO2 supply) and white light (0.04% CO2 supply), respectively. Protein storage was detected at 20.3 ± 1.0% and 24.8 ± 1.3% in C. vulgaris and S. obliquus biomasses under white light with a 5% CO2 and 0.04% CO2 supply, respectively. The removal of P, N, chemical oxygen demand, and biological oxygen demand resulted in 80–100%, 75–100%, 26–35%, and 0–20%, respectively.

A Thorough Insight into the Biofilm Properties of Potential Fish Pathogen Tenacibaculum discolor Strain FMCC B487

Tenacibaculum discolor develops biofilm in marine aquaculture production tanks and is identified as one of the causative agents of tenacibaculosis, a bacterial disease that causes significant losses in marine aquaculture production. In this study, the biofilm characteristics of T. discolor strain FMCC B487 were evaluated. Cell growth and biofilm formation and development were studied in miniaturized assays to assess the effect of different levels of environmental factors temperature and salinity, as well as the presence of monosaccharides potentially found in aquaculture hatcheries. The ability of the strain to grow and develop strong biofilms in ambient to high temperatures and at salinities above 20 g/L was shown. Mannose was the monosaccharide with the most prominent impact on the T. discolor strain FMCC B487 biofilm. The composition of planktonic cell extract, biofilm extracts, and extracellular polymeric substances (EPS) produced by T. discolor strain FMCC B487 were investigated by means of colorimetric and fluorometric assays as well as analyses by electrophoresis, gas chromatography, and high-performance size-exclusion chromatography coupled with a multiangle light scattering detector, revealing the dominance of proteins and lipids and the absence of high-molecular-weight polysaccharides. This information may serve as a basis for considering anti-biofilm strategies against the pathogen T. discolor.

Fungicide Use Patterns in Select United States Wine Grape Production Regions.

Wine grape production (Vitis sp.) in the United States requires fungicide inputs for disease control. Currently, there is limited data available on vineyard fungicide use patterns. This information is important in developing tailored recommendations for disease management and fungicide stewardship. In this paper, we summarize the wine grape vineyard fungicide use patterns from four major regions: Napa and Sonoma valleys (California), Willamette Valley (Oregon), Columbia Valley (Washington), and several smaller regions east of the Mississippi River in years 2009 to 2020. We learned that the average in-season total fungicide applications ranged regionally from 5.6 to 8. The most commonly applied Fungicide Resistance Action Committee (FRAC) codes in spray programs were FRAC 3, 13, and M02 across all regions, with some variation to the top four groups in each region. Most applications were made on 14-day intervals; however, shorter intervals (7-day) were favored early season, and longer intervals (21-day) were favored late season. Tank-mixing multiple active ingredients was common east of the Mississippi River during all stages of grape development; this action was typically favored during the bloom period in other regions. In a subset of records that participated in FRAC 11 fungicide resistance testing, the average number of FRAC 11 applications after testing was reduced to either no applications or one application in Napa and Sonoma valleys. This survey provides regionally specific data related to fungicide stewardship practices that could be a focus for future stewardship messaging and fungicide resistance selection training, including total product use (selection events), spray intervals (selection pressure), and tank mixing (selection management).[Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Safety, health, and environmental risk assessment of the aromatic outlet of Imam Khomeini Petrochemical Company using LOPA and fuzzy-LOPA and pollutants and control actions using the Bow-tie method.

Today, with the development of the industry, the occurrence of accidents caused by the release and explosion of chemical and toxic substances in industrial units has increased, and these accidents sometimes cause irreparable damage to human life and the environment. According to a study by the American Petroleum Institute, of the recent major accidents in the last 30 years, 44% are related to machinery failure and 12% are caused by unknown factors and lack of information. Therefore, equipment risk control is aimed at preventing large and dangerous accident. The present study, the performance of LOPA and fuzzy-LOPA methods was compared toward the risk assessment of Imam Khomeini Petrochemical Company under certainty and uncertainty of data. This comparison was done in order to a conceptual method with high certainty to assess high-level hazards leading to health and safety risks and environmental pollution. First, the health, safety hazards and environmental aspects were identified via the HAZOP method. Then, a risk assessment was performed using the LOPA method. The fuzzification, severity, and likelihood of each risk were considered as an input variable and risk probability as an output variable. Finally, was the methods used in our analysis were compared and the Bow-tie software was used to draw a Bow-tie diagram to control and reduce the risks. As a result, a total of 50 safety and health hazards and 37 environmental aspects were identified in the aromatic outlet of the studied company using the HAZOP method. The most critical risks identified were operational activities in feed and product tanks; flammable materials pumping; blocking the flare path; and releasing H2S gas. The results showed that the production of air pollutants in the power supply unit, disposal of waste from reactor tanks, disposal of waste from condensate tanks, and fire and explosion of the reactor are high-level environmental risks. In the conditions of uncertainty or the absence of information related to the probability and severity of the risk scenario, among the mentioned methods. The result showed that errors in the risk assessment were reduced to an acceptable extent by using Fuzzy LOPA method.

Modelling and capacity allocation optimization of a combined pumped storage/wind/photovoltaic/hydrogen production system based on the consumption of surplus wind and photovoltaics and reduction of hydrogen production cost

To achieve “carbon neutrality”, clean energy such as wind and solar energy is being developed, but due to the random and intermittent characteristics of wind energy and photovoltaics, the instability of grid connections and the abandoning wind and photovoltaics need to be addressed urgently. This paper proposes a method to solve the problems of grid connection and abandonment in wind and photovoltaic generation systems, that is, to establish a combined pumped storage/wind/photovoltaic/hydrogen production system through the pumped storage and hydrogen production system. The system consists of a pumped storage/wind/photovoltaic complementary subsystem and a hydrogen production subsystem. First, different models in the system are modelled using Simulink and the characteristics of the models are analysed. Subsequently, the wind turbine model and the PV model are simulated to derive the wind-PV complementary characteristic curves, and it is found that the load demand cannot be met by relying on wind-PV complementary power generation alone. To achieve system stability and economy, pumped storage is configured to smooth the output of wind power and PV. After comprehensive consideration, the optimal pumped storage capacity is determined to be 1000 MW. Then, through the simulation of the pumped storage/wind/photovoltaic system, it is found that even though pumped storage can absorb the wind and photovoltaic outputs, there is still a surplus when the wind and photovoltaic outputs are in excess. Therefore, this surplus energy is used for hydrogen production and the configuration of the hydrogen production system is optimized using a particle swarm algorithm to minimize the cost per unit of hydrogen production. After particle swarm optimization, it was determined that the unit cost of hydrogen production was minimized to 3.54 CNY/Nm3 for the configuration of 55 electrolysis tanks of 4 MW and 219 lead-acid tanks of 1 MW/2 MWh. Meanwhile, the electrolysis tank simulation model and the lead-acid battery simulation model were used to obtain maps of their operating conditions, hydrogen production and hydrogen storage tank pressure. In view of the addition of an energy storage system to the wind and photovoltaic generation system, this paper comprehensively considers the two energy storage modes of pumped storage and hydrogen production, and proposes a corresponding capacity optimization configuration scheme, which has reference value for improving the consumption and stability of wind and photovoltaics and realizing the sustainable utilization of clean energy.

VST RESIDUAL LIFE ESTIMATION ALGORITHM BASED ON LOW-CYCLE LOADING CRITERION IN REAL TIME

Due to the significant wear and tear of oil and petroleum product tanks in Russia, there is a need for continuous monitoring of their technical condition. The article provides an overview and analysis of methods for assessing the stress-strain state of the tank wall. The advantages and disadvantages of these methods were identified, as well as the possibility of assessing the stress-strain state of the tank in real time was justified. Calculations of ring stresses were made according to the moment-free theory of shells, calculation of equivalent Von-Mises stresses in ANSYS medium. An analysis of calculations was carried out, the conclusions of which are consistent with the literature data. As a result of the application of various shell theories, production faces a dilemma - or the ability to get operational, but less accurate results and predictions, or use strain gauges to determine wall stresses, or use additional tools in the form of 3D scanning of the tank surface with subsequent processing of data and transfer of the obtained model to the FEA-environment to detect equivalent stresses by Von-Mises, while any efficiency of the process is lost. Strain gauges are one of the effective means of assessing the stress-strain state of the tank wall, but their calibration is not an easy task. The existing diagnostic tools do not allow to estimate the residual wall life by low-cycle loading in real time. An algorithm is proposed for estimating the residual life of the RVS according to the criterion of low-cycle loading in real time, which allows detecting potential problems in advance, maintaining the tank in a timely manner, while reducing the risk of an accident and subsequent more expensive repairs, and promptly taking measures in case of an emergency. The developed algorithm can be used for continuous tank diagnostics.

Bench-Scale Biopile Hydrocarbons Removal Optimization Using the Response Surface Methodology and Simultaneous Optimization

Nowadays, the generation of vast volumes of oily sludges is associated with industrial operations such as production, pretreatment, processing, water separation, and storage tank maintenance. Biopiles can be more efficient than other techniques for removing hydrocarbons in sludges, but their removal efficiency depends on operating variables. The goal of this study was to determine the best operating variable ranges at the bench scale to simultaneously optimize hydrocarbons removal in a biopile prototype. This research was conducted within the framework of a Cuban project and used an experimental protocol that integrates several standardized methods and engineering procedures into a series of steps. A Box-Behnken design was implemented for three factors and two response variables: the mass of Total Petroleum Hydrocarbons (TPH) removed and the final concentration of TPH. A simultaneous optimum was obtained for an initial TPH concentration of 39 278 mg·kg-1 and contents of texturizer and moisture of 6,45 and 25,95%, respectively. The obtained variable ranges ensure a compromise solution that maximizes the mass of TPH removed and keeps the contaminant concentration under the Cuban disposal regulations. The results have been used to set up the biopiles at a pilot scale as a subsequent stage of the project.

Energy-sustainable hospitals: Integration of a novel compound parabolic concentrator system with two storage tanks for domestic hot water production at high and low temperatures

Hospital buildings are known to be energy-intensive, since they are operated all year round at high costs, contain sophisticated medical equipment, and follow strict cleaning practices and environmental regulations. Domestic hot water consumption accounts for most of the energy consumption in hospital buildings.The objective of this research work is to study the energy performance of a novel compound parabolic concentrator system connected to two heat exchangers arranged in series, in turn, connected to two storage tanks that supply domestic hot water to two different hospital users. The first user requires high temperatures for laboratories, cleaning, sterilization of operating room instruments, and so on, while the second user requires lower temperatures mostly represented by health services. To guarantee the supply of the thermal energy needs, an external integration system was connected to each storage tank. A calculation scheme was created in a transient simulation environment that provides dynamically all temperatures at the output of the various system components and all thermal exchanges through each component. Starting from a reference configuration, a parametric simulation was carried out by varying the size of the plant components. The research aim was to evaluate the influence of the component sizes on the plant's transient behaviour by means of a qualitative-quantitative determination of the monthly and yearly system energy exchanges and some performance indicators, such as the solar fraction, solar efficiency and fuel consumption on a monthly and yearly basis. The outcomes of this research demonstrated that the choice of the storage tank volumes and the secondary circuit flow rate allows designers to allocate the solar energy produced between the two users, while the collector area and the primary circuit flow rate allow designers to fix the fraction of overall thermal demand to be satisfied and the efficiency of solar energy conversion into thermal energy to the fluid. Finally, similarly to the f-chart method, some empirical correlations are proposed to rapidly verify the system performance without using any transient simulation tool.

Multivariate calibration strategy in simultaneous determination of temperature properties of petroleum diesel by near infrared spectrometry

It is essential to control the quality of diesel products so that they comply with relevant fuel specifications, however, the quality assessments rely upon conventional wet chemical analyses that are costly and time consuming. Rapid, simultaneous quality measurement enabling immediate online optimisation for process control and blending offers tremendous cost savings by minimising product quality give-away, shipment demurrage, tank inventory, and laboratory analysis. In this study, the use of near infrared spectroscopy and chemometrics demonstrates a straightforward workflow for simultaneous determination of the petroleum diesel’s boiling point at 95% recovery (T95), flash point (FP), cloud point (CP), and cetane index (CI) calibration development. It involved appropriate spectral region selection, calibration/validation set partition, data pre-processing, regression modelling and validation. Based on the calibration and validation results, the supervised learning models that are obtained from a combination region of 4000–4800 cm−1 on a randomly selected calibration set managed to deliver promising predictive performance in terms of coefficient of determination for prediction (r2P/T95 ≥ 0.94, r2P/FP ≥ 0.89, r2P/CP ≥ 0.89, r2P/CI ≥ 0.993), root mean square error of prediction (RMSEP (T95) ≤ 5.2°C, RMSEP (FP) ≤ 2.0°C, RMSEP (CP) ≤ 2.4°C, RMSEP (CI) ≤ 0.3), and ratio of performance deviation (RPD (T95) ≥ 3.7, RPD (FP) ≥ 3.0, RPD (CP) ≥ 2.9, RPD (CI) ≥ 11). Regardless of principal component regression or partial least square regression on either the multiplicative scattering corrected spectra or Savitzky-Golay second derivative spectra, the developed models met respective ASTM reproducibility requirements, and were considered adequate for immediate quality assessment of diesel.

Identification of critical operational hazards in a biogas upgrading pilot plant through a multi-criteria decision-making and FTOPSIS-HAZOP approach

The hazard and operability analysis (HAZOP) is one of the most popular approaches for risk management, although weaknesses such as the limited number of risk factors considered, the inaccuracy of experts’ opinions or the limited process knowledge might compromise the quality of the results. In this context, conventional HAZOP analysis can be improved via a Fuzzy Multi-Attribute HAZOP technique. Under a fuzzy logic, Analytic Hierarchy Process and the Technique for Order of Preference by Similarity to Ideal Solution can be combined with Fuzzy Multi-Attribute HAZOP to determine the weight of risk factors and to rank critical hazards. The inherent risks biogas upgrading, such as explosiveness, overpressure, or premature deterioration of equipment, should be identified for planning of critical control points and for enabling a proper maintenance plan. Previous models were applied to a photosynthetic biogas upgrading and a biogas-to-polyhydroxyalkanoates production pilot plant in order to identify and get more information about associated risks of the operation of these valorization biotechnologies, sometimes not fully provided by HAZOP analysis. Biotrickling filter and the polyhydroxyalkanoates production tank were identified as the most critical subsystems, with contributions of 33.3% and 17.8% to the overall risk, respectively (within quartile 1, Q1). Additionally, biogas and recycling/feeding streams clustered a large number of operational risks (up to 83.4% of total risk within Q1). The sensibility analysis demonstrated the reliability and robustness of the final ranking. The results of this analysis will support preventive maintenance by identifying critical monitored points when scaling-up biological biogas upgrading processes.

SOME ISSUES OF REAGENT TREATMENT OF INDUSTRIAL WASTEWATER FROM FOOD INDUSTRY

The object of the study is wastewater generated during the salting of fish, containing suspended solids, phosphates, chlorides, organic contaminants, etc., as well as wastewater generated after washing the equipment used in the production and process tanks. Waste water, in accordance with the established requirements, is treated with chemical reagents, where the coagulant of the KEMIRA PAX 20 series (a solution of aluminum polyoxychloride based on Al3+) is used as a coagulant. The purpose of the work: for more economical use of aluminum polyoxychloride, based on stoichiometric calculations of reaction equations, select the optimal dose of coagulant necessary to intensify the processes of flocculation, taking into account the pH of the waste water, determine the alkali consumption and the conditions for its dosing into the treated water.

Biological effects of inhaled crude oil vapor. II. Pulmonary effects

Workers involved in oil exploration and production in the upstream petroleum industry are exposed to crude oil vapor (COV). COV levels in the proximity of workers during production tank gauging and opening of thief hatches can exceed regulatory standards, and several deaths have occurred after opening thief hatches. There is a paucity of information regarding the effects of COV inhalation in the lung. To address these knowledge gaps, the present hazard identification study was undertaken to investigate the effects of an acute, single inhalation exposure (6 h) or a 28 d sub-chronic exposure (6 h/d × 4 d/wk × 4 wks) to COV (300 ppm; Macondo well surrogate oil) on ventilatory and non-ventilatory functions of the lung in a rat model 1 and 28 d after acute exposure, and 1, 28 and 90 d following sub-chronic exposure. Basal airway resistance was increased 90 d post-sub-chronic exposure, but reactivity to methacholine (MCh) was unaffected. In the isolated, perfused trachea preparation the inhibitory effect of the airway epithelium on reactivity to MCh was increased at 90 d post-exposure. Efferent cholinergic nerve activity regulating airway smooth muscle was unaffected by COV exposure. Acute exposure did not affect basal airway epithelial ion transport, but 28 d after sub-chronic exposure alterations in active (Na+ and Cl¯) and passive ion transport occurred. COV treatment did not affect lung vascular permeability. The findings indicate that acute and sub-chronic COV inhalation does not appreciably affect ventilatory properties of the rat, but transient changes in airway epithelium occur.

Effect of Silver Water Produced by an Engineered Device Designed to Food Industry

Hygienic norms in the food and beverages production systems should be permanently monitored to prevent contamination with pathogens which could cause diseases in humans and animals. As regards the industrial scale of food and beverages production, the maximum extension of the shelf life is an essential task. Peracetic acid (CH3COOOH) is frequently applied in sanitation procedures of production piping and product tanks, but if it is not rinsed well, could drastically affect organoleptic characteristics of the products. Silver water (containing Ag+) could replace the use of peracetic acid. A device for efficient production of silver water is constructed. The silver content of the water produced is determined by atomic absorption spectroscopy, UV-Vis and IR spectral analysis. It is found that minimal inhibitory concentration (MIC) of 1 μg silver content inhibited the yeast (Saccharomyces cerevisiae ATCC 200060) growth (24 ± 1 mm mean inhibition zone) on a similar rate as 30 μg kanamycin (27 ± 1 mm). Bacterial (Escherichia coli ATCC 47093) growth inhibited by 1.5 μg silver content (18 ± 1 mm) is comparable to 10 μg ampicillin (17 ± 1 mm) but not to 30 μg kanamycin (35 ± 1 mm).

Fiber-Optic Hydrophone Based on Michelson's Interferometer with Active Stabilization for Liquid Volume Measurement.

Sensing technologies using optical fibers have been studied and applied since the 1970s in oil and gas, industrial, medical, aerospace, and civil areas. Detecting ultrasound acoustic waves through fiber-optic hydrophone (FOH) sensors can be one solution for continuous measurement of volumes inside production tanks used by these industries. This work presents an FOH system composed of two optical fiber coils made with commercial single mode fiber (SMF) working in the sensor head of a Michelson’s interferometer (MI) supported by an active stabilization mechanism that drives another optical coil wound around a piezoelectric actuator (PZT) in the reference arm to mitigate external mechanical and thermal noise from the environment. A 1000 mL glass graduated cylinder filled with water is used as a test tank, inside which the sensor head and an ultrasound source are placed. For detection, amplitudes and phases are measured, and machine learning algorithms predict their respective liquid volumes. The acoustic waves create patterns electronically detected with resolution of 1 mL and sensitivity of 340 mrad/mL and 70 mvolts/mL. The nonlinear behavior of both measurands requires classification, distance metrics, and regression algorithms to define an adequate model. The results show the system can determine liquid volumes with an accuracy of 99.4% using a k-nearest neighbors (k-NN) classification with one neighbor and Manhattan’s distance. Moreover, Gaussian process regression using rational quadratic metrics presented a root mean squared error (RMSE) of 0.211 mL.

Microbial water quality of the copepod Acartia tonsa in cultures for use as live feed

Live feed is important for rearing of marine larvae in the aquaculture industry and copepods have shown some superior qualities compared to Artemia and rotifers. Whereas the nutritional composition is one factor contributing to this, the mechanisms behind better performance are not fully known. Microbial conditions could be an important contributor. We characterized the microbiota associated with intensive rearing of the calanoid copepod Acartia tonsa by culture-dependent and independent methods. During three independent 14-days production cycles, qualitative and quantitative aspects of incoming water, algal cultures (Rhodomonas baltica), and copepod production tanks were measured using flow cytometry with RNA-staining, plate counts, 16S-rDNA amplicon sequencing and hemolytic activity. Assessment of the microbial quality was done based on r/K-theory, presence/absence of hemolytic activity and taxonomic characterization. None of the sample types showed detectable bacteria with hemolytic activity. The incoming water was dominated by opportunistic r-strategists, whereas the algae reservoir was dominated by K-strategist. The production tank had dominance of r-strategists. Abundance of genera with known pathogenic members were not detected in any samples, except the incoming water samples. However, the incoming water contributed with only 1–3% of the cells to the production tank. Because of this, the intensively reared A. tonsa cultures appear to have a good microbial water quality as live feed for marine larvae, and the microbial water quality may contribute to the good results obtained when using copepods during first feeding.