Feeding Operations Research Articles

Geospatial and co-occurrence analysis of antibiotics, hormones, and UV filters in the Chesapeake Bay (USA) to confirm inputs from wastewater treatment plants, septic systems, and animal feeding operations

Previous studies have reported select contaminants of emerging concern (CECs) in limited areas of the Chesapeake Bay (USA), but no comprehensive efforts have been conducted. In this work, 43 antibiotics, 9 hormones, 11 UV filters, and sucralose, were measured in matched water, sediment, and oyster samples from 58 sites. The highest sucralose concentration was 3051 ng L-1 in a subwatershed with 4.43 million liters of wastewater effluent per day (MLD) and 4385 septic systems. Although antibiotic occurrence was generally low in subwatersheds located in less populated areas, 102 ng L-1 ciprofloxacin was detected downstream of 0.58 MLD wastewater effluent and 10 animal feeding operations. Hormones were not regularly detected in water (2%) or oysters (37%), but the high detection frequencies in sediment (74%) were associated with septic systems. UV filters were ubiquitously detected in oysters, and octisalate exhibited the highest concentration (423 ng g-1). Oyster-phase oxybenzone and aqueous-phase sucralose concentrations were significantly correlated to wastewater effluent and septic systems, respectively. Toxicity outcomes were predicted for homosalate and octisalate throughout the Bay, and antimicrobial resistance concerns were noted for the Chester River. The geospatial and co-occurrence relationships constitute crucial advances to understanding CEC occurrence in the Chesapeake Bay and elsewhere.

Enhanced photodegradation of p-arsanilic acid by oxalate in goethite heterogeneous system under UVA irradiation.

The widespread used organoarsenicals have drawn attention for decades due to their potential environment risks. In this study, a heterogeneous system of goethite/oxalate irradiated using UVA light (λ = 365 nm) was applied for the removal of ASA, a kind of organoarsenicals used in animal feeding operations as additives, from the aqueous phase through photodegradation. Results showed that the presence of 5 mM of oxalate significantly enhanced the photodegradation efficiency of ASA in the 0.1 g/L of goethite suspended system from 28 to ~100% within 180 min reaction at pH 5. Acid conditions favored the photoreaction rate, compared with neutral and basic conditions. This reaction process was also influenced by the initial concentration of oxalate and ASA. Furthermore, the mechanism study was conducted by quenching experiments and revealed the important roles of·OH in the degradation of ASA in the goethite/oxalate/UVA system. By analyzing the reaction products, both inorganic arsenic (As(III) and As(V)) and ammonia were detected during the photodegradation of ASA. These findings help to gain a better understanding of the geochemical behavior of ASA in surface water and can also provide a potential treatment method for the organoarsenicals contaminated water.

Evaluating the potential of nanofiltration membranes for removing ammonium, nitrate, and nitrite in drinking water sources

Advanced drinking water treatment process using nanofiltration (NF) membranes has gained attention recently because it removes many challenging constituents in contaminated surface waters, such as dissolved organics and heavy metals. However, much literature has reported high variations and uncertainties of NF membranes for removing nitrogen compounds in the contaminated water—ammonium (NH4+), nitrates (NO3−), and nitrites (NO2−). This study aimed to identify the ability of commercial NF membranes to remove NH4+, NO2−, and NO3− and clarify the mechanisms underlying their transport through NF membranes. This was examined by evaluating their rejection by three commercial NF membranes using artificial and actual river waters under various conditions (variable permeate flux, temperature, pH, and ionic strength). Ammonium commonly showed the highest removal among the three nitrogen compounds, followed by nitrites and nitrates. Interestingly, ammonium removal varied considerably from 6% to 86%, depending on the membrane type and operating conditions. The results indicated that the selected nitrogen compounds (NH4+, NO2−, and NO3−) could be highly rejected depending on the clearance between their hydrated radius and the membrane's pore walls. Further, the rejection of the lowest molecular-weight nitrogen compound (NH4+) could be higher than NO2− and NO3− due to its highest energy barrier and larger hydrated radius. This study suggests that compliance with the drinking water regulations of NH4+, NO2−, and NO3− can be reliably achieved by selecting appropriate membrane types and predicting the range of their removal under various feed water quality and operating conditions.

Modeling and Analysis of Air Pollution and Environmental Justice: The Case for North Carolina's Hog Concentrated Animal Feeding Operations.

Concentrated animal feeding operations (CAFOs) emit pollutants that can cause negative impacts on human health. The concentration of hog production in North Carolina raises concerns regarding the disproportionate exposure of vulnerable communities to air pollution from CAFOs. We investigated whether exposure to gaseous ammonia () and hydrogen sulfide () (in 2019) differs between subpopulations by examining demographics, including race/ethnicity, age, educational attainment, language proficiency, and socioeconomic status. We used an Air Monitoring Station (AMS)/Environmental Protection Agency (EPA) Regulatory Model (AERMOD)-based Human Exposure Model (version 3) to estimate ambient concentrations of and from hog farms in Duplin County and its surrounding counties in North Carolina and estimate subsequent exposures of communities within of Duplin County, North Carolina, or the Duplin County Region. We combined estimated exposures with 2016 American Community Summary Census data, at the block group level, using spatial analysis to investigate whether exposures to these pollutants differ by race and ethnicity, age, income, education, and language proficiency. Based on these estimations, we assessed associated exposure risks to the impacted communities and used multivariable regression modeling to evaluate the relationship between average ammonia exposures from Duplin regional hog farms and the presence of vulnerable populations. The average [] annual estimated concentration of and in the Duplin County Region is and , respectively. The maximum average annual ambient concentrations are estimated at and for and , respectively. Our descriptive analysis reveals that people of low income, people of color, people with low educational attainment, and the linguistically isolated in the Duplin Region are disproportionately exposed to higher levels of pollutants than the average exposure for residents. Alternatively, our statistical results suggests that after adjusting for covariates, communities of color are associated with 1.70% (95% CI: , 0.44) lower concentrations per 1-SD increase. One-standard deviation increases in the adults with low educational attainment and children years of age is associated with 1.26% (95% CI: , 3.33) and 1.20% (95% CI: , 3.05) higher exposure per 1-SD increase, respectively. Exposures to and differed by race and ethnicity, educational attainment, language proficiency, and socioeconomic status. The observed associations between exposure to CAFO-generated pollutants and sociodemographic indicators differed among demographics. The disproportionate distribution of hog facilities and resulting pollutant exposures among communities may have adverse environmental and human health impacts, raising environmental justice concerns. https://doi.org/10.1289/EHP11344.

An efficient data-driven desalination approach for the element-scale forward osmosis (FO)-reverse osmosis (RO) hybrid systems

Freshwater shortages are a consequence of the rapid increase in population, and desalination of saltwater has gained popularity as an alternative water treatment method in recent years. To date, the forward osmosis-reverse osmosis (FO-RO) hybrid technology has been proposed as a low-energy and environmentally friendly next-generation seawater desalination process. Scaling up the FO-RO hybrid system significantly affects the success of a commercial-scale process. However, neither the ideal structure nor the membrane components for plate-and-frame FO (PFFO) and spiral-wound FO (SWFO) are known. This study aims to explore and optimize the performance of SWFO-RO and PFFO-RO hybrid element-scale systems in the desalination of seawater. The results showed that both hybrid systems could yield high water recovery under optimal operating conditions. The prediction of the system performance (water flux and reverse salt flux) by artificial intelligence was considerably better (R > 0.99, root mean square error <5%) than that of conventional mass balance models. A Markov-based decision tree successfully classified the water flux level in hybrid systems. An optimal set of operational conditions for each membrane system was proposed. For example, in RO, a combination of the feed solution (FS) flow rate (≥17.5 L/min), FS concentration (<17,500 ppm), and operation pressure (<35 bar) would result in high water permeability (>40 LMH). In addition, five SWFO elements and four PFFO elements should be the optimal numbers of FO membranes in the hybrid FO-RO system for effective seawater desalination, especially for long-term operation.

First Measurement of Ambient Air Quality on the Rural Lower Eastern Shore of Maryland

Concerns about atmospheric ammonia have been expressed recently by some on the Lower Eastern Shore (LES) of Maryland, which lies between the Chesapeake Bay and the Atlantic Ocean on the Delmarva peninsula. Agriculture, seafood and tourism are responsible for a significant fraction of the economic activity on the LES. The USDA 2017 census reported there were ~100 Concentrated Animal Feeding Operations (CAFOs) raising nearly 63 M chickens per year across Somerset and Worcester Counties. We report air quality data collected from sites near Princess Anne, Somerset County, and near Pocomoke City, Worcester County, to address air quality concerns by examining the influence of chicken farms on ammonia in ambient air on the LES. Within a two-mile radius of the Worcester County site, CAFO operations house ~1.6 million birds. The Princess Anne site is comparable to the Pocomoke City site in agricultural use and population demographics but has only a few chicken houses within two miles. The first 33 months of LES ammonia data are presented, and their significance is discussed relative to other ammonia studies. The 33-month average concentration of ammonia in Pocomoke was 10.3 ± 0.08 ppb, more than double that in Princess Anne, which was 4.7 ± 0.04 ppb.

A laboratory-scale compression feed screw for characterizing continuous feeding of dense granular materials

Compression feed screws are commonly used in biorefineries for the continuous feeding of biomass feedstock into reactors. Developing methods to assess the feasibility of feeding granular materials in a compression feed screw is critical for reducing solids handling issues during operation. A laboratory-scale compression feed screw has been built to measure critical process parameters of the feeding operation, namely the driving torque and the mass flow rate. The process parameters of two granular materials, microcrystalline cellulose Avicel PH-200 and milled corn stover are measured using the laboratory-scale feeder. The results show that a larger torque is required to feed corn stover than Avicel PH-200, even though the former consists of more compressible particles. Further, the device can capture real-time fluctuations in the process parameters during operation. The laboratory-scale feeder can be used to compare the feeding of different granular materials and the measured parameters can be used to validate predictive models for a compression screw feeding process.

Technical note: Isolating methane emissions from animal feeding operations in an interfering location

Abstract. Agricultural emissions, including those from concentrated animal feeding operations (CAFOs) for beef and dairy cattle, make up a large portion of the United States' total greenhouse gas (GHG) emissions. However, many CAFOs reside in areas where methane (CH4) from oil and natural gas (ONG) complicates the quantification of CAFO emissions. Traditional approaches to quantify emissions in such regions often relied on inventory subtraction of other known sources. We compare the results of two approaches to attribute the CAFO CH4 emission rate from the total CH4 emission rate derived from an aircraft mass balance technique. These methods make use of the mixing ratio data of CH4, ethane (C2H6), and ammonia (NH3) that were collected simultaneously in-flight downwind of CAFOs in northeastern Colorado. The first approach, the subtraction method (SM), is similar to inventory subtraction, except the amount to be removed is derived from the observed C2H6 to CH4 ratio rather than an inventory estimate. The results from this approach showed high uncertainty, primarily due to how error propagates through subtraction. Alternatively, multivariate regression (MVR) can be used to estimate CAFO CH4 emissions using the NH3 emission rate and an NH3 to CH4 ratio. These results showed significantly less uncertainty. We identified criteria to determine the best attribution method; these criteria can support attribution in other regions. The final emission estimates for the CAFOs presented here were 13 ± 3 g of CH4 per head per hour and 13 ± 2 g of NH3 per head per hour. These estimates are higher than the inventory of the US Environmental Protection Agency (EPA) and previous studies highlighting the need for more measurements of CH4 and NH3 emission rates.

Evaluation of a novel electrode design for high voltage pulse ore pre-concentration

High Voltage Pulse (HVP) enabled ore preconcentration has the potential to provide large energy savings and upgrade Run-of-Mine ores. The concept is well established in laboratory settings but is yet to be demonstrated at the throughputs needed for industrial uptake of the technology. To scale up this concept from laboratory batch tests to a continuous operation, a novel grizzly-electrode design that integrates pulse discharges for particle breakage and size-based separation into a single step has been patented. In the initial evaluation of the system, two cylindrical electrode bars were adopted with an experiment design to simulate continuous feeding operation. Synthetic particles and a low-grade gold-copper ore were used for the initial evaluation. The evaluation showed pre-concentration can be achieved. Factors affecting the system performance were identified and limitations of the grizzly electrodes are discussed.

ОТБОР ПРОБ ПРИ ОЦЕНКЕ КАЧЕСТВА СМЕШИВАНИЯ

The improvement of the technological process of preparing dry loose feed mixtures is associated with an increase in the structure of feed rations for farm animals in the conditions of farms. It is noted that an increase in the digestibility and palatability of feed, a decrease in the specific energy consumption for the production of feed mixtures depends on the quality of their mixing. The methodological basis of the work was the results of studies of recent years by leading domestic scientists in the field of improving the technological processes for preparing feed mixtures, design and operating parameters of mixers. The analysis of sampling methods is given: periodic for batch mixers; cumulative, allowing to obtain a generalized sample, more representative of the mixing process, also applicable to the study of batch mixers; using special devices - samplers to obtain the most accurate samples. The importance of selecting a control component oriented to the functional features of the mixers, regardless of the sampling method used, is highlighted when monitoring the homogeneity of the mixture. The analysis of existing studies showed a wide range of control components, methods of sampling and separation of components in the study of the mixing process by machines of various designs and principles of operation. The analysis of the works showed that in order to reduce the time spent on isolating the control component and ensure the reliability of the studies, it is necessary to take into account the nature of the mixed cultures. When choosing seeds of sweet clover, clover, millet as control components, a sample mass of 5 grams is sufficient; seeds of beets, buckwheat, wheat and barley, a sample mass of 100 grams is sufficient; seeds of peas, corn, a sample mass of 300 grams is sufficient. A sieve classifier with optimal selection of the mixture with the possibility of separating in sieve or sieve analysis is noted as the most applicable for the isolation of the control component. It is recommended to focus on the method of periodic sampling when examining batch mixers. The cumulative sampling method using samplers is recommended for investigating the performance of continuous mixers and evaluating the overall quality of mixing in batch mixers.

A new PERVAPTM membrane to enhance the dehydration of isopropanol by pervaporation

The performance of a new commercial polyvinyl alcohol (PVA) membrane (PERVAPTM 4100HF) was investigated and compared with a standard membrane (PERVAPTM 4100) for the dehydration of isopropanol (isopropyl alcohol) with an azeotropic point using pervaporation process. Both membranes were also characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, and contact angle (CA) goniometer. The results showed that the PERVAP™ 4100HF was thinner (1–1.5 μm) and had a lower degree of cross-linking than the PERVAP™ 4100HF (2–3 μm). The effect of the feed water concentration and operating temperature on the membranes separation performance in terms of the permeation flux, separation factor, selectivity, and permeance was investigated. The water permeates in the PERVAP™ 4100HF (∼3350 GPU) was seven times higher than that in PERVAP™ 4100 (∼463 GPU) at 70 °C and for 7 wt.% of water concentration in the feed. The water/isopropanol selectivity of the new membrane under these operating conditions was very high (∼17,000). The total permeation flux of water and isopropyl alcohol (IPA) was increased with the feedwater concentration (0.0690–1.0275 and 0.0079–0.6384 kg/m2.hr) for PERVAP™ 4100HF and PERVAP™ 4100, respectively with feed water concentration increased from 7 to 18 wt.%. The temperature dependence of the pervaporation behaviors was investigated in detail in terms of the Arrhenius activation energy. The effect of the feedwater concentration on the Arrhenius activation energy was also studied to evaluate the mass transfer across the membrane under other operating conditions, such as high temperatures and low feedwater concentrations. The new membrane PERVAP™ 4100HF exhibited the best dehydration properties at water concentrations in the azeotropic region and below, making it possible to pervaporate even at low feedwater concentrations.

Liquid-liquid chromatography isolation of Petasites hybridus sesquiterpenes and their LC-HR-MS/MS and NMR characterization

Petasites hybridus L. (butterbur, Asteraceae) is a well-known medicinal plant traditionally used as a remedy for neurological, respiratory, cardiovascular, and gastrointestinal disorders. Eremophilane-type sesquiterpenes (petasins) are considered to be the major bioactive constituents of butterbur. However, efficient methods to isolate high-purity petasins in sufficient amounts for further analytical and biological testing are lacking. In this study, various sesquiterpenes were separated from a methanol rootstock extract of P. hybridus with liquid-liquid chromatography (LLC). The appropriate biphasic solvent system was selected using the predictive thermodynamic model COSMO-RS and shake-flask experiments. After the selection of the feed (extract) concentration and operating flow rate, a batch LLC experiment was performed with n-hexane/ethyl acetate/methanol/water 5/1/5/1 (v/v/v/v). For those LLC fractions containing petasin derivatives with purities < 95%, a preparative high-performance liquid chromatography purification step followed. All isolated compounds were identified by state-of-the-art spectroscopic methods, i.e., liquid chromatography coupled with high-resolution tandem mass spectrometry and nuclear magnetic resonance techniques. As a result, six compounds were obtained, namely 8β-hydroxyeremophil-7(11)-en-12,8-olide, 2-[(angeloyl)oxy]eremophil-7(11)-en-12,8-olide, 8α/β-H-eremophil-7(11)-en-12,8-olide, neopetasin, petasin, and isopetasin. The isolated petasins can be further used as reference materials for standardization and pharmacological evaluation.

Effect of humidification and cell heating on the operational stability of polymer electrolyte membrane fuel cell

Because of its clean or zero-emission nature, the PEM fuel cell is considered a potential energy conversion device for power production. The performance of the PEM fuel cell is known to be influenced by many parameters, such as operating temperature, pressure, and humidification of the reactants. In addition, the operational stability of the PEM fuel cell under these conditions with the purging of water during its operation should also be studied to understand the performance of the PEM fuel cell. Therefore, this paper brings out the effects of cell humidification and cell heating on the performance, especially the operational stability concerning the liquid water removal of the PEM fuel cell. The experiments are conducted on a single PEM fuel cell with mixed flow distributors operating on different cell temperatures and humidification conditions. At dry feed operation of the PEM fuel cell at ambient condition, the cell utilizes around 80.3% of water generated for its membrane hydration, i.e., self-humidification. When the PEM fuel cell is operated at full humidification (100% RH) on both sides, the membrane is well hydrated, and the cell attains the maximum power density of 0.25 W/cm2, which is 56% more than dry feed operation. The results of the experiments at static current density demonstrate membrane hydration is the significant factor for both stable operation and efficient power output. External purging must periodically be carried out to stabilize the cell due to voltage fluctuations. The major outcome of the current study is to establish the connection between hydration and the stability of the PEM fuel cell.

Numerical performance analysis of solid oxide fuel cell stacks with internal ammonia cracking

Ammonia-fueled operation of solid oxide fuel cells is a promising alternative to their hydrogen-fueled operation. However, high ammonia decomposition rates at elevated operating temperatures of the solid oxide cells lead to a significant temperature drop at the stack inlet, causing increased thermal stresses. A multi-scale model is used in this study to investigate stack performance under direct feed and external pre-cracking of ammonia. Additionally, the effects of co- and counter-flow configurations, gas inflow temperatures, current density, and air flow rate on the stack performance under direct ammonia feed are examined. The simulation results show that for gas inlet temperatures above 750 °C, the power densities with direct feed and external cracking of ammonia differ by less than 5%. Moreover, it is indicated that the thermal stresses are lowest for the co-flow case, which decrease with decreasing gas inlet temperature and current density and with increasing air flow. Finally, this study shows that under practically applicable operating conditions, the risk of mechanical failure of the cells under direct ammonia feed operation is small.

Modeling and optimization of salt and boron removal in reverse osmosis system

Seawater reverse osmosis (SWRO) is a mature technology that has significantly evolved over the past few decades. However, boron removal remains a serious challenge. A new RO transport model was developed by combining the irreversible thermodynamic theory and solution-diffusion theory and considering the solute concentration polarization phenomenon. The developed RO model supplemented by the use of variable solution properties and transport parameters was validated with existing data and, it was then applied to identify the main operation parameters and assess their effect on SWRO performance, with the aim of minimizing specific energy consumption and satisfying water quality requirements. The results showed that the solution-diffusion approach, cannot capture the interaction between transported boron and water species. For high pH, applied feed pressure, and flow rate, the convective transport of boron through the seawater membrane is remarkable and its contribution to the overall boron flux can reach over 20 %. The feed operating conditions have significantly influenced the quality of the water production and the amount of energy used. The results showed that the optimal SEC increased by approximately 40 %, and the recovery ratio decreased by 11.6 % as the feed flow rate increased from 0.002 to 0.005 m3/s.

20 Years of Environmental Injustice and the Mississippi Hog Industry: Spatial and Statistical Analyses for Low-Wealth Communities and Communities of Color

Background: The industrialization and consolidation of the animal agriculture industry has led to the rise of concentrated animal feeding operations (CAFOs). CAFOs and their runoff have been linked to deleterious effects on environmental and human health. A previous study demonstrated that hog CAFOs were disproportionately sited within or near low-wealth communities and communities of color, raising environmental justice concerns. This study aimed at replicated prior methods to assess whether environmental injustices that were identified nearly 20 years ago have been adequately addressed through policy and/or other mechanisms. Methods: CAFO data, including facility size and manure generation, were taken from the Mississippi Department of Environmental Quality. Buffer analysis was conducted using CAFO data and block-group sociodemographic data from the 2018 5-year American Community Survey to measure CAFO proximity to communities of concern (low-wealth, communities of color). Statistical analyses (quintile analysis, prevalence ratios, negative binomial regression, spearman correlation assessments) were utilized to measure the correlation between CAFO presence and sociodemographics. Results: The CAFOs in Mississippi were located in block groups that have an average or greater African American population compared with the state. The highest number of hog CAFOs were within block groups with 15.9%–36.9% of people below the poverty line. Conclusion: Race and socioeconomic status could be factors in determining the likelihood of living near a hog CAFO in Mississippi, yet these analyses did not demonstrate a positive correlation between race, socioeconomic status, and the presence of CAFOs. Considering the potential harm that hog CAFOs pose to low-wealth populations and communities of color, policy recommendations include a moratorium on expansion; phasing out the largest CAFOs in the state; and stricter enforcement of environmental protections with regards to animal agriculture.

EFFECT OF HEAT TRANSFER ON FIRE DEVELOPMENT STAGES AND SPREAD OF FIRE

Fire has played a leading role in the development of civilizations and fire and the energy produced by fire have been effective in every turning point throughout history. The main energy of the cannons used by Fatih Sultan Mehmet in the conquest of Istanbul in 1453 is the combustion reaction. On the basis of the industrial revolution and mechanization, the main energy source is the combustion reaction. Today, the combustion reaction is the basis of the operation of automobiles, heating, feeding and many other processes. Cooking, heating, lighting and pottery making, which are also the most basic needs, have always been thanks to fire. In this way, fire has become so important for human beings that it is the subject of myths. However, especially in the last century, with the rapid development of technology, the variety of building materials, items and devices used in the construction of living spaces has increased and the use of synthetic-based products as raw materials has become widespread in these areas. This situation can cause today's fires to be much more destructive. In today's fires, many different fire gases occur. Likewise, the heat value produced by fires can be much higher. This not only facilitates the growth and spread of fires, but also makes extinguishing efforts more difficult. It absolutely necessitates the use of personal protection equipment so that the heat and fire gases generated do not affect the extinguishing personnel. In recent years, many firefighters who entered the fire environment without using personal protective equipment or wearing them incorrectly have been injured or lost their lives. In this paper, the heat transfer patterns and fire stages that cause the rapid growth of indoor fires are examined, and the indicators that may be the harbinger of possible dangers in these stages are emphasized.

Dispersal and Risk Factors for Airborne Escherichia coli in the Proximity to Beef Cattle Feedlots

California Leafy Green Products Handler Marketing Agreement (LGMA) established food safety metrics with guidance recommendations of 366 m (1,200 feet) and 1,609 m (1 mile) distances between production fields of leafy greens and a concentrated animal feeding operation (CAFO) containing >1,000 and >80,000 head of cattle, respectively. This study evaluated the effect of these distance metrics and environmental factors on the occurrence of airborneEscherichia coliin proximity to seven commercial beef cattle feedlots located in Imperial Valley, California. A total of 168 air samples were collected from seven beef cattle feedlots during March and April 2020, which were the months implicated in the 2018 Yuma Arizona lettuce outbreak of E. coli O157:H7. The distance between air sampling sites and the edge of the feedlot ranged from ∼0 to ∼2,200 m (∼1.3 mile), with each sample comprised of 1,000 L of processed air taken at a 1.2 m elevation over a 10-minute duration. E. colicolonies were enumerated on CHROMagar ECC selective agar and confirmed with conventional PCR. Meteorological data (air temperature, wind speed, wind direction, relative humidity) were collectedin situ. The prevalence and mean concentration ofE. coliwere 6.55% (11/168) and 0.09 CFU per 1,000 L of air, with positive samples limited to within 37 m (120 ft) of the feedlot.Based on logistic regression, the odds of airborne E. coli detection were associated with little to no wind and close proximity to a feedlot. This pilot study found limited dispersal of airborne E. coli in proximity to commercial feedlots in Imperial Valley, with light-to-no wind and proximity within 37 m of a feedlot significant factor-associated airborne E. coli in this produce-growing region of California.

Photovoice Reveals Residents' Concerns for Air and Water Quality in Industry-Impacted Rural Community.

Rural communities of color in the southeastern U.S. experience a high burden of environmental hazards from concentrated industry placement. Community-engaged research and qualitative methods can improve our understanding of meaning-making in a community impacted by polluting facilities. This study applies the photovoice method to assess how a predominantly African American community in rural North Carolina, impacted by a landfill and confined animal feeding operations (CAFOs), perceives their health-related quality of life (HRQoL). Two research questions were developed with community-based partners: (a) How do environmental health concerns in this community influence residents' perceptions of their HRQoL? and (b) How do community and county factors facilitate or inhibit community organizing around these concerns? Three photo assignment sessions were held to engage participants in discussions related to the research questions. Researchers analyzed discussion audio recordings and identified themes related to concerns about the following issues: health and quality of life, the landfill industry's influence on community cohesion and self-determination, and actions to address environmental injustice in Sampson County. Photovoice benefits community-engaged researchers by providing a process for assessing the research interests of a community. Photovoice also serves community organizers by providing residents with a structured way to discuss their lived experiences and strategize ways to reduce hazard exposure.

Research on remote emergency control breaking device for trolley type circuit breaker switchgear

High-voltage transmission and distribution lines use circuit breaker switchgear for stopping and feeding operations. Therefore, if abnormal emergencies in circuit breaker shutdown and transmission, it is urgent to carry out remote control switching to solve the problem that the circuit breaker cannot be operated with power when the remote control fails. This paper develops a trolley type circuit breaker switchgear remote emergency control shunting device, which can remotely shunt the circuit breakers on the switchgear and sink control cabinet manually in situ. And we also discusses the hardware and software design principle as well as the advantage analysis to ensure the personal safety of the operators on site and provide reference for improving the safety, economy, flexibility and reliability of the power grid.