Outdoor recreation is one of the fastest-growing economic sectors in the United States and is being used by communities to support economic development, social prosperity, and environmental ...protection. For communities that have whitewater rivers, whitewater recreation provides a powerful economic alternative to ailing extractive and manufacturing industries that have long dominated rural communities. In order to promulgate a whitewater recreation-based economy, stakeholders need information about their whitewater resources, including how often and when they can be paddled. The overall goal of this study, therefore, was to develop an analytical framework that quantifies boatable days, that is, the number of days that streamflow exceeds the minimum boatable flow levels needed to paddle downstream. Importantly, our framework uses publicly available streamflow and minimum boatable flow information that can be used to quantify boatable days for any whitewater run in the country, irrespective of watershed size or river flashiness. We applied the framework to three world-class whitewater rivers in the central Appalachian Mountains, USA, and found abundant and stable boating opportunities throughout the year. Our results underscore the potential for strategically developing whitewater recreation as a means of economic diversification and highlight how boatable days analysis can be used for quantifying whitewater resources.
The “whitewater zone” represents a critical maritime feature intimately tied to ship identification and stealth capabilities. In this study, the large eddy simulation method is employed to analyze ...wake fields under varying operational conditions, and the influence of propeller turbulence and bubble wakes on the “whitewater zone” is investigated in conjunction with a self-built optical testing platform. The results indicate that an increase in propeller speed serves to stabilize the vortex structure but also results in a unimodal signal waveform. Moreover, the behavior of bubbles exerts a significant impact on the flow field structure. The coalescence and division of large bubbles play a primary role in altering the flow field structure of the “whitewater zone,” consequently accelerating the mixing and diffusion of the “whitewater.” The smaller bubbles exhibit prolonged retention times and a broader disturbance area within the surrounding flow field. The research conclusion has certain reference significance for the future development of ocean exploration technology.
•An optical test platform for identifying the “whitewater area” is constructed.•Details on the “whitewater area” flow field characteristics is elucidated.•The effect of the “whitewater area” on the laser transmission signal is examined.
External auditory canal exostoses (EACE) are bony formations that develop insidiously in the auditory meatus from chronic exposure to cold water and, in severe cases, require surgery. This condition ...has been understudied in the whitewater kayakers and not yet studied in the riverboarding population. Precautions such as earplugs are thought to prevent the formation of EACE because they mechanically block cold water from contacting the sensitive skin in the external auditory canal; however, earplugs are not commonly utilized by athletes. Inquiring about hobbies and the use of protective equipment can be done during osteopathic physicians' preventive care visits.
This article aims to determine the prevalence of EACE in Colorado whitewater athletes and their attitudes about wearing ear protection before and after an educational intervention directed at increasing awareness and prevention of EACE.
In July 2020, participants of this cross-sectional study completed a 10-min survey that collected demographics, whitewater experience, and perceptions of EACE, followed by an educational intervention. Participant ears were photographed utilizing a digital otoscope to assess EACE, and severity ratings were categorized into one of four occlusion levels: none (0%), mild (<25%), moderate (25-75%), or severe (>75%). Spearman correlation coefficients and Wilcoxon signed-rank tests were utilized to assess changes in attitudes before and after the educational intervention.
Eighty-one participants (mean SD age = 36.3 12.6 years, 25.9% female) completed the study: 74 kayakers and seven riverboarders. After the intervention, 60.5% (49/81) (p<0.001) reported greater understanding of EACE and 75.0% (60/80) were more likely to wear ear protection (p<0.001). Most (58.0%, 47/81) never wore ear protection. Of the 61 (75.0%) participants with at least one ear severity rating, most (55.7%, 34/61) had moderate EACE, 29.5% (18/61) had no to mild EACE, and 14.8% (9/61) had severe EACE (p<0.001). Impaired hearing was the biggest barrier to utilizing ear protection (51.6%, 33/64).
Our results suggested that the educational intervention improved understanding of EACE and may increase utilization of ear protection in this population. Such prevention efforts may lead to better health of whitewater paddlers by reducing the incidence of EACE. Encouraging osteopathic physicians to inquire about hobbies and protective equipment during primary care preventive visits is essential to help keep athletes in the river doing what they love for longer, contributing to a healthier and happier whole person.
Seasonal concentrations of total, particulate and dissolved Al, Cu, Cd, Cr, Fe, Pb and Ni were analyzed in surface water and total metals in sediment samples from black and whitewater rivers within ...the Itacoatiara City, Central Amazon. Metals concentrations in water and sediment samples demonstrated that even though urbanization and agricultural practices are common in this region. Metal concentrations in sediments samples are acceptable regarding the recommended levels for protection of aquatic life. From this work, which is the first trace elements study in the main tributaries from Itacoatiara region, we conclude that metals are present in a particulate form, being easier to be transported to other aquatic bodies. During flooding periods an increase of Al, Fe and total organic compound (TOC) in almost water sampling points was observed.
In the wood-free paper industry, whitewater is usually a mixture of additives for paper production. We are currently lacking an efficient, cost-effective purification technology for their removal. In ...closed whitewater cycles the additives accumulate, causing adverse production problems, such as the formation of slime and pitch. The aim of our study was to find an effective bio-based strategy for whitewater treatment using a selection of indigenous bacterial isolates. We first obtained a large collection of bacterial isolates and then tested them individually by simple plate and spectrophotometric methods for their ability to degrade the papermaking additives, i.e., carbohydrates, resin acids, alkyl ketene dimers, polyvinyl alcohol, latex, and azo and fluorescent dyes. We examined correlation between carbon source use, genera, and inoculum source of isolates using two multivariate methods: principal component analysis and FreeViz projection. Of the 318 bacterial isolates, we selected a consortium of four strains (
sp. CST37-CF,
sp. BLA14-CF,
sp. AKD4-BF and
sp. RES19-BTP) that degrade the entire spectrum of tested additives by means of dissolved organic carbon measurements. A proof-of-concept study on a pilot scale was then performed by immobilizing the artificial consortium of the four strains and inserting them into a 33-liter, tubular flow-through reactor with a retention time of < 15 h. The consortium caused an 88% reduction in the COD of the whitewater, even after 21 days.
Incident shortwave solar radiation entering the ocean depends on albedo α and plays an important role in the temperature variability and pathogen mortality of the nearshore region. As foam has an ...elevated albedo, open-ocean albedo parameterizations include whitecapping effects through a wind-based foam fraction. However, surfzone depth-limited wave breaking does not require wind. Surfzone albedo observations are very rare, the variability of surfzone albedo is not known, and parameterizations are not available. New, year-long upwelling and downwelling shortwave radiation observations were made from the Scripps Institution of Oceanography pier spanning the surfzone and inner-shelf. Surfzone albedo was elevated due to foam with mean observed albedo of α=0.15 and one-minute average albedo as high as α=0.45, far exceeding expected albedo (0.06) from standard parameterizations. Using a pier-mounted GoPro camera, an image-based albedo parameterization is developed that estimates the fractional foam area to derive albedo. This parameterization has high skill (r2=0.90) on time scales as short as a wave period (9 s). A second wave-model based parameterization for (hourly) averaged albedo is developed relating the non-dimensional roller energy dissipation to the mean foam fraction and thus albedo. The parameterization has good skill (r2=0.68) and resolves cross-shore albedo variations. These new parameterizations can be used where imagery is available or wave models are applicable, and can be used to constrain local heat budgets and pathogen mortality.
•Surfzone albedo can reach 0.45 and varies rapidly with breaking-wave foam.•Image-based parameterization accurately predicts albedo at wave time scales.•Wave-model based parameterization predicts time-averaged cross-shore albedo.
Water plays several essential roles in paper manufacturing. It serves as a suspending medium and a swelling agent for the fibres, dispersing and forming them into a uniform sheet during the initial ...stage of the papermaking process. It also serves as the solvent for a variety of chemicals and additives to adjust product quality. Water reclamation has always been a momentous task in the pulp and paper (P&P) industry. The main driving forces for the adoption of process water and wastewater treatment technologies are environmental regulations, costs of wastewater discharge and the high cost of freshwater. Recent developments have made it possible to not only reduce water consumption and environmental impacts, but also to recover treated water and valuable compounds such as fibres, making water recycling technologies cost-efficient. Thus, the economic viability of these technologies has played an important role in their application. The technologies applied, the level of reduction in water consumption and the extent of water recycling are different for each mill, since the quality of whitewater and wastewater varies depending on the raw materials and products. The maintenance of the balance between partial equilibria of process variables such as water flowrates, pulp consistency, physiochemical, thermal and microbiological properties through water management is important for maintaining efficient water use and lowering the need for consumption of additional fresh water.
Display omitted
•The process and waste waters of recycled paper mills can be treated for reuse.•Water usage can be reduced through process water and wastewater management.•There are consequences of closing the process water loop without proper treatment.•It is possible to achieve zero liquid discharge with a combination of technologies.
PDF
