Outdoor Studies Research Articles

Enhancing Signal-to-Noise Ratio in Vehicle-to-Vehicle Visible Light Communication Systems Through Diverse LED Array Transmitter Geometries

In this paper, a novel method is introduced to enhance the performance of vehicle-to-vehicle (V2V) visible light communication (VLC) by employing different transmitter (Tx) light-emitting diode (LED) array arrangements with different LED orientations. Improving the signal-to-noise ratio (SNR) is crucial for V2V VLC systems to provide long communication ranges. For this purpose, six transmitter configurations are proposed: single-LED transmitters, as well as 3 × 3 square-, single hexagonal-, octagonal-, 5 × 5 square-, and honeycomb hexagonal-shaped LED arrays. Indoor VLC studies using LED arrays offer a uniform SNR, while outdoor studies focus on optimizing the receiver side to enhance system performance. This paper optimizes system performance by increasing the SNR and communication range of V2V VLC systems by changing the geometry of the Tx LED array and LED orientations. A V2V VLC system using on–off keying (OOK) is modeled in MATLAB, and the SNR and bit error rate (BER) are simulated for different Tx configurations. Our results show that the honeycomb hexagonal transmitter design provides a 19% improvement in system performance with a spacing of 1 cm, and maintains a 16% improvement when the array size is reduced by a factor of 100, making it smaller than one of the smallest industrial headlight modules.

Light induced degradation of CIGS solar cells

Considering warranted lifetimes of PV modules of typically 20-30 years, the performance stability of PV modules is one of the most crucial factors regarding power generation and yield. Long term outdoor performance studies depict realistic operation conditions best, but the correlated nature of e.g. irradiance and temperature impedes the physical interpretation. The possibility to control and tune the conditions in laboratory experiments enables to decompose effects, that are typically overlayed in outdoor experiments. This way, laboratory are crucial to interpret the results obtained in outdoor degradation studies. One driving force of degradation of CIGS modules is light exposure. In literature the focus of light induced degradation (LID) of CIGS modules and solar cells is on metastable changes analyzed on time scales ranging from minutes to hours. In this work we expose industrially produced encapsulated CIGS solar cells for more than 1000 h to light with varied intensity under varied temperature conditions. Such, we aim to study temperature and light intensity dependencies of the observed performance changes. Furthermore, we study the influence of applied bias by comparing LID at short and open circuit. We demonstrate that LID under short circuit conditions leads to VOC degradation, while being temperature assisted and not dependent on the irradiance intensity. CIGS solar cells kept at open circuit conditions appear to be stable under illumination. Exploiting the one diode model, we further connect the observed temperature assisted performance loss to enhanced recombination with lower ideality factor, in comparison to the dominant recombination process before degradation.

Presence and (dis)connectedness – the influence of smartphones usage on human–nature and human–human interactions in outdoor studies

Interactions between students and nature and students and their peers are central to learning processes in outdoor studies programs. This paper draws on symbolic interactionist social theory to interpret participants’ experiences of smartphone usage and its impact on human–nature and human–human interactions. The findings are derived from a collective case study using semi-structured interviews with educators and focus group interviews with students enrolled in outdoor studies programs in Norway. Two primary themes were identified through reflexive thematic analysis: perceptions of nature and attentiveness to peers. Each of these themes illustrates the fluctuating presence and (dis) connectedness of students and the implications of this for learning out-of-doors. On the one hand, the findings suggest that the use of smartphones reduces students’ sensory perception of nature and their attentiveness to interactions with their peers. On the other hand, smartphones and their access to online networks can contribute to the continuity of learning experiences between indoor and outdoor learning, as well as beyond the formal learning environment. Taken together, this inquiry offers new insights into the challenges of tertiary level teaching and learning outdoors in spaces that are mediated (at times) by interactions with smartphones and associated media infrastructures.

Radiocarbon Flux Measurements Provide Insight into Why a Pyroligneous Acid Product Stimulates Plant Growth.

Agriculture in the 21st century faces many formidable challenges with the growing global population. Increasing demands on the planet's natural resources already tax existing agricultural practices. Today, many farmers are using biochemical treatments to improve their yields. Commercialized organic biostimulants exist in the form of pyroligneous acid generated by burning agricultural waste products. Recently, we examined the mechanisms through which a commercial pyroligneous acid product, Coriphol™, manufactured by Corigin Solutions, Inc., stimulates plant growth. During the 2023 growing season, outdoor studies were conducted in soybean to examine the effects of different Coriphol™ treatment concentrations on plant growth. Plant height, number of leaves, and leaf size were positively impacted in a dose-dependent manner with 2 gallon/acre soil treatments being optimal. At harvest, this level of treatment boosted crop yield by 40%. To gain an understanding of why Coriphol™ improves plant fitness, follow-up laboratory-based studies were conducted using radiocarbon flux analysis. Here, radioactive 11CO2 was administered to live plants and comparisons were made between untreated soybean plants and plants treated at an equivalent Coriphol™ dose of 2 gallons/acre. Leaf metabolites were analyzed using radio-high-performance liquid chromatography for [11C]-chlorophyll (Chl) a and b components, as well as [11C]-β-carotene (β-Car) where fractional yields were used to calculate metabolic rates of synthesis. Altogether, Coriphol™ treatment boosted rates of Chl a, Chl b, and β-Car biosynthesis 3-fold, 2.6-fold, and 4.7-fold, respectively, and also increased their metabolic turnover 2.2-fold, 2.1-fold, and 3.9-fold, respectively. Also, the Chl a/b ratio increased from 3.1 to 3.4 with treatment. Altogether, these effects contributed to a 13.8% increase in leaf carbon capture.

Achilles Tendon Loading during Running Estimated Via Shear Wave Tensiometry: A Step Toward Wearable Kinetic Analysis.

Understanding muscle-tendon forces (e.g., triceps surae and Achilles tendon) during locomotion may aid in the assessment of human performance, injury risk, and rehabilitation progress. Shear wave tensiometry is a noninvasive technique for assessing in vivo tendon forces that has been recently adapted to a wearable technology. However, previous laboratory-based and outdoor tensiometry studies have not evaluated running. This study was undertaken to assess the capacity for shear wave tensiometry to produce valid measures of Achilles tendon loading during running at a range of speeds. Participants walked (1.34 m·s -1 ) and ran (2.68, 3.35, and 4.47 m·s -1 ) on an instrumented treadmill while shear wave tensiometers recorded Achilles tendon wave speeds simultaneously with whole-body kinematic and ground reaction force data. A simple isometric task allowed for the participant-specific conversion of Achilles tendon wave speeds to forces. Achilles tendon forces were compared with ankle torque measures obtained independently via inverse dynamics analyses. Differences in Achilles tendon wave speed, Achilles tendon force, and ankle torque across walking and running speeds were analyzed with linear mixed-effects models. Achilles tendon wave speed, Achilles tendon force, and ankle torque exhibited similar temporal patterns across the stance phase of walking and running. Significant monotonic increases in peak Achilles tendon wave speed (56.0-83.8 m·s -1 ), Achilles tendon force (44.0-98.7 N·kg -1 ), and ankle torque (1.72-3.68 N·m·(kg -1 )) were observed with increasing locomotion speed (1.34-4.47 m·s -1 ). Tensiometry estimates of peak Achilles tendon force during running (8.2-10.1 body weights) were within the range of those estimated previously via indirect methods. These results set the stage for using tensiometry to evaluate Achilles tendon loading during unobstructed athletic movements, such as running, performed in the field.

The public-health significance of far-UVC-induced indoor ozone and its associated secondary chemistry.

There has been much recent interest in whole-room far-UVC (wavelength around 222 nm) to markedly and safely reduce overall levels of airborne pathogens in occupied indoor locations. Far-UVC light produces very low levels of ozone-in real-world scenarios induced ozone levels of less than 10 ppb, and much less in moderately or well-ventilated rooms compliant with US far-UVC dose recommendations, and very much less in rooms compliant with international far-UVC dose standards. At these very low ozone levels, there is no epidemiological evidence of increased health risks from any of the very large outdoor ozone studies, whether from ozone alone or from ozone plus associated pollutants. Indoors, at the low ozone concentrations of relevance here, ozone does not react rapidly enough with preexisting airborne volatile organic compounds to compete with even extremely low levels of room ventilation, so significant ozone-induced ultrafine particle production is very unlikely. Direct measurements in real-life room scenarios are consistent with these conclusions. A potential exception is the cleaning material limonene, which has an unusually high ozone interaction cross-section; in the far-UVC context, turning off far-UVC lights during cleaning with limonene products would be reasonable.

Survival and nutritional requirements for overwintering Drosophila suzukii (Diptera: Drosophilidae) in Kentucky.

The ability to cope with novel climates is a key determinant of an invasive species' success. Drosophila suzukii (Matsumura, 1931) is an invasive fruit pest, and its seasonality varies across its range. Current evidence suggests that D. suzukii occurs year-round in warmer climates but has low overwintering survival in colder climates and relies on refuges or reinvades each spring. Here, we assessed the capacity of D. suzukii ability to overwinter in Kentucky, a temperate mid-latitude state with relatively mild but variable winters. We tracked year-round population changes for 3 yr and observed the highest populations in early winter months. Following an annual population crash in winter, small numbers of flies remained through the late winter and spring. We also conducted outdoor cage studies to determine the extent to which food resources and microhabitat impact survival and postwinter fecundity under natural conditions. Flies with no food had poor survival during the warmest periods of winter, and flies in all treatments had lower survival in the coldest month. Provisioning flies with either artificial diet or wild berries improved survival. As a follow-up, we determined whether D. suzukii could survive and reproduce after long-term exposure to a typical winter temperature on various wild berries. Drosophila suzukii had the highest survival on privet (Ligustrum sp.), but all berry types yielded higher survival than flies without food. Our results suggest that noncrop berries play an important role for overwintering D. suzukii, and as winters warm the availability of wild berries could influence early-season populations.

Outdoor Thermal Comfort Optimization in a Cold Climate to Mitigate the Level of Urban Heat Island in an Urban Area

Climatic and micro-climatic phenomena such as summer heat waves and Urban Heat Island (UHI) are increasingly endangering the city’s livability and safety. The importance of urban features on the UHI effect encourages us to consider the configuration of urban elements to improve cities’ sustainability and livability. Most solutions are viable when a city redevelops and new areas are built to focus on aspects such as optimum design and the orientation of building masses and streets, which affect thermal comfort. This research looks beyond outdoor thermal comfort studies using UHI data and geoprocessing techniques in Tallinn, Estonia. This study supposes that designing urban canyons with proper orientation helps to mitigate the UHI effect by maximizing outdoor thermal comfort at the pedestrian level during hot summer days. In addition, optimizing the orientation of buildings makes it possible to create shaded and cooler areas for pedestrians, reducing surface temperature, which may create more comfortable and sustainable urban environments with lower energy demands and reduced heat-related health risks. This research aims to generate valuable insights into how urban environments can be designed and configured to improve sustainability, livability, and outdoor thermal comfort for pedestrians. According to the study results, researchers can identify the most effective interventions to achieve these objectives by leveraging UHI data and geoprocessing techniques and using CFD simulations. This evaluation is beneficial in guiding urban planners and architects in proposing mitigation solutions to enhance thermal comfort in cities and creating suitable conditions for approved thermal comfort levels. Results of the study show that in the location used for the survey, Tallinn, Estonia, the orientation of West-East offers the optimum level of comfort regarding thermal comfort and surface temperature in the urban environment.

A Review on the Impacts of Urban Heat Islands on Outdoor Thermal Comfort

The worsening urban heat island (UHI) effect poses a great challenge to the thermal comfort of people outdoors. However, there has not been a summary of the mechanisms by which UHI affects outdoor thermal comfort (OTC). This paper reviews the commonly used OTC evaluation indexes, data collection methods, and mitigation measures and discusses the relationship between UHI and OTC. The review is limited to peer-reviewed journal publications found in five databases: Science Direct, Scopus, Google Scholar, PubMed, and Web of Science. The review results indicate that physiological equivalent temperature (PET), universal thermal climate index (UTCI), and wet bulb globe temperature (WBGT) are the most widely used indexes in outdoor thermal comfort studies. The data collection methods mainly include questionnaire surveys, measurement, simulation, and formula calculation. There are four main approaches to mitigating the UHI effect in order to improve the comfort of people outdoors: vegetation strategies, water strategies, urban planning strategies, and material strategies. Future research can focus on developing OTC research methods and indexes and combine thermal comfort with visual comfort, auditory comfort, etc. to better evaluate the overall comfort.

Governance of nature-based health promotion: public policy and volunteer organisations’ innovations of outdoor activities among urban youth

ABSTRACT This article explores multilevel governance networking and innovation to better understand how nature-based public health can be promoted at a grassroot level within an urban context. Hence, the leading research question examines the extent of networking and collaboration within state and municipal policymaking and the implementation of socially inclusive nature-based activities among urban youths conducted by local volunteer organisations. Multilevel networking and collaboration represent an analytical alternative to bottom-up and top-down strategies, which dominate the socio-political policies of outdoor studies in several countries. The exploration draws on empirical research conducted in 2020 based on a qualitative design. A website review was carried out to analyse facilitated nature-based health innovations embracing educational activities, leadership, and organisation run by local volunteer organisations targeting youth aged 6–19 across Oslo, Norway’s capital. The investigation was substantiated by twenty-eight interviews with leaders of volunteer organisations and primary healthcare coordinators in five of Oslo’s fifteen city districts, exploring their organisational experiences and reflections on nature-based innovations as a measure to promote health. The governance approach revealed several paradoxes and ambiguities in policy and practice. For example, there is a gap between the policy vision and available resources. There is also a need to understand better the complex networks and collaboration of public agencies and dedicated volunteers, their organisations, and interests. Furthermore, the continuous professionalisation of the voluntary sector and its significance in building a governance infrastructure that increases the capability of ongoing nature-based activity innovations need to be developed to meet policy goals and young people’s needs and interests. Social inequalities were reported among those participating in nature-based activities and those who were not engaged. This pattern follows the well-documented spatial distribution of socioeconomic disparities.

Electrical Efficiency Investigation on Photovoltaic Thermal Collector with Two Different Coolants

The design and development of a photovoltaic thermal (PVT) collector were developed in this study, and electrical and electrical thermal efficiency were assessed. To improve system performance, two types of coolants were employed, liquid and liquid-based MnO nanofluid. Flow rates ranging from 1 to 4 liters per minute (LPM) for the interval of 1.0 LPM were employed, together with a 0.1% concentration of manganese oxide (MnO) nanofluid. Various parametric investigations, including electrical power generation, glazing surface temperature, electrical efficiency, and electrical thermal efficiency, were carried out on testing days, which were clear and sunny. Outdoor studies for the aforementioned nanofluids and liquids were carried out at volume flow rates ranging from 1 to 4 LPM, which can be compared for reference to a freestanding PV system. The research of two efficiency levels, electrical and electrical thermal, revealed that MnO water nanofluid provides better photovoltaic energy conversion than water nanofluid and stand-alone PV systems. In this study, three different domains were examined: stand-alone PV, liquid-based PVT collector, and liquid-based MnO nanofluids. The stand-alone PV system achieved a lower performance, the liquid-based MnO performed better, and the liquid-based PVT achieved an intermediate level.

Demand for outdoor recreation in a time of a pandemic

The extent of the health benefits of contact with nature came to the fore during the health crisis. However, studies do not fully appreciate the effect of the type of natural environment to which individuals are exposed. The studies often use a very vague category of “green space” for the purpose. We apply social sciences analytical concepts to analyze demands for recreational uses of both forests and ocean beaches in a time of sanitary crisis. Our studies use data from two regional surveys applied to a representative sample of the Aquitaine population. We underline the social inequalities with regard to access to forest and ocean beaches, even though outdoor recreation is free of charge most of the time. We also identify salient differences between uses, motivations, and risk perceptions in both of the natural settings. We discuss how such discrepancies are inherited from previously constructed social representations. We believe that public health studies could benefit greatly from the achievements of several decades of research in the field of outdoor studies.

A Platform for Outdoor Real-Time Characterization of Photovoltaic Technologies

In recent years, thin-film and organic photovoltaic (OPV) technologies have been increasingly used as alternatives to conventional technologies due to their low weight, portability, and ease of installation. Outdoor characterization studies allow knowing the real performances of these photovoltaic (PV) technologies in different environmental conditions. Therefore, to address the above, this article presents the hardware–software design and implementation of an integrated and scalable platform for performing the outdoor real-time characterization of modern PV/OPV technologies located at different altitudes. The platform allows knowing the outdoor performance of PV/OPV technologies in real environmental conditions by acquiring data from different monitoring stations located at different altitudes. The proposed platform allows characterizing solar panels and mini-modules and acquiring relevant information to analyze power generation capacity and efficiency. Furthermore, other devices for new PV technologies characterization can be easily added, achieving a scale-up of the platform. A preliminary study of the outdoor performance of emerging PV/OPV technologies was carried out at three different altitudes in a tropical climate region. From the results, the copper indium gallium selenide (CIGS) technology presents the best outdoor performance with an average PCE of 9.64%; the OPV technology has the best behavior at high temperatures with a voltage loss rate of 0.0206 V/°C; and the cadmium telluride (CdTe) technology is the most affected by temperature, with a voltage loss rate of 0.0803 V/°C.

The Effect of the Potamogeton crispus on Phosphorus Changes throughout Growth and Decomposition: A Comparison of Indoor and Outdoor Studies

Phosphorus (P) transport and transformation in water were investigated using Potamogeton crispus. To compare and evaluate our indoor experiment with outdoor data, we used the simultaneous indoor experiment and field observation approach. The effects of P. crispus growth and decomposition on P concentrations were investigated. P. crispus significantly reduced the P content of different forms in the water during the growth period, and significantly increased the P content of different forms in the water during the decomposition period, according to the findings. As a result, the P level of the water varied seasonally and regularly. The pH and dissolved oxygen (DO) of environmental factors in the water revealed an increasing trend during the P. crispus growth period and a negative trend during the decomposition period. The changing trend of chlorophyll a (Chl-a) and alkaline phosphatase activity (APA) was inverse, decreasing during the growth period of P. crispus and increasing during the decomposition period. In the P. crispus growth environment, all forms of P in water were positively related to Chl-a, APA, and pH, and negatively related to DO. The comparison of the indoor experiment with field data revealed that the indoor experiment number has a larger standard deviation, indicating that the indoor experiment data fluctuated substantially. The indoor simulation experiment has the disadvantage of large data fluctuation. As a result, this study demonstrated that P. crispus regulated the P cycle in water via absorption and changes in environmental factors during the growth period, and released nutrients via decomposition during the decomposition period, thereby influencing the migration and transformation of P in the water. This work may be used as a reference for future research into the process of P exchange between sediments and water interfaces caused by P. crispus.

Effect of depth of flooding on growth and fecundity of fall panicum (Panicum dichotomiflorum)

AbstractFall panicum is the most prevalent and problematic weed in rice in Florida. Outdoor studies were conducted in 2021 to determine the effect of flooding on fall panicum growth and its ability to produce and develop panicles. Fall panicum at the two- to four-leaf and four- to six-leaf stages of development were flooded in stock tanks maintained at flooding depths of 0, 10, 15, 20, and 30 cm for 56 d. Plant height, number of tillers and leaves, leaf area, shoot biomass, root biomass, and panicle branches for both fall panicum leaf stages of development decreased with increasing flooding depth. Fall panicum flooded at the two- to four-leaf stage survived flood depth of 15 cm, whereas plants flooded at the four- to six-leaf stage survived and emerged from a flood depth of up to 20 cm. The 10-cm flood depth resulted in the tallest plants with more leaves, tillers, and leaf area for both growth stages. The probability of fall panicum survival and ability to produce panicles decreased as flood depth increased. Flood depth required for 50% survival for four- to six-leaf-stage plants was estimated to occur at 14 cm, whereas that for plants at the two- to four-leaf stage occurred at 12 cm. The flood depth required to reduce panicle branch production by 50% was estimated to be 15 and 20 cm for two- to four-leaf, and four- to six-leaf-stage plants, respectively. These results show that flooding >10 cm is required to significantly reduce fall panicum survival and ability to produce panicles. Since flood level in rice is usually maintained at an average of 10 cm, chemical weed control will be important to supplement flooding for effective control of fall panicum in rice.

Гибридный концентраторно-планарный фотоэлектрический модуль с гетероструктурными солнечными элементами

The paper presents a promising solution for photovoltaic modules that provides overcoming the main conceptual limitation for the concentrator concept in photovoltaics - the impossibility to convert diffused (scattered) solar radiation coming to the panel of sunlight concentrators. The design of a hybrid concentrator-planar photovoltaic module based on heterostructure solar cells: A3B5 triple-junction and Si-HJT is presented. The results of initial outdoor studies of the module output characteristics are discussed and estimates of its energy efficiency are given.

Hybrid concentrator-planar photovoltaic module with heterostructure solar cells

The paper presents a promising solution for photovoltaic modules that provides overcoming the main conceptual limitation for the concentrator concept in photovoltaics --- the impossibility to convert diffused (scattered) solar radiation coming to the panel of sunlight concentrators. The design of a hybrid concentrator-planar photovoltaic module based on heterostructure solar cells: A3B5 triple-junction and Si-HJT is presented. The results of initial outdoor studies of the module output characteristics are discussed and estimates of its energy efficiency are given. Keywords: hybrid concentrator-planar photovoltaic module, multijunction solar cell, Si-HJT planar photoconverter, diffusely scattered radiation.

An investigation of outdoor recreational users' willingness to participate in aquatic invasive plant control

Aquatic invasive plants (AIP) can have major ecological and socioeconomic impacts. Effective management is therefore essential. Because many biological invasions occur in places used for outdoor recreation, recreational user engagement is widely advocated. However, few studies have been conducted on recreational user engagement in biological control, and those that exist have placed surprisingly little emphasis on several predictors used in the field of outdoor studies. This study explored the factors influencing recreational users' willingness to participate in the control of AIP at a freshwater lake in south-western France. Five actions were proposed (i.e. changing the way one uses the lake, informing others about the plants, being part of a manual removal collective, sending information to a participative citizen observatory, giving money). In a first step, I demonstrated that the proportion of the individuals' responses on the five willingness to engage is statistically different. In a second step, I estimated binomial regressions to model willingness to participate in the various management actions. Predictors drawn from the invasion sciences and outdoor research studies were included. Recreational factors were highly significant in predicting willingness to participate. Good knowledge of the invasive plants and participation in water-based activities were also strong positive incentives to participate. The influences of perceived impacts (both positive and negative) and education were ambivalent. The study confirms that not all forms of participation in the control of biological invasion are considered of equal value. To increase the scale of community-based management, it is therefore important to define precisely what is being asked of the recreational user.

Applying a diagnostic equation for maximum urban heat island intensity based on local climate zones for Guangzhou, China

The Urban Heat Island (UHI) is a widely studied phenomenon, characterized by unique spatiotemporal variations depending on urban structure. Seeking a simple and rapid method to monitor the Urban Heat Island Intensity (UHII) for local urban area with multiple inner morphology is essential for energy saving, citizen health, and urban planning. Hence, this study proposed a diagnostic equation for daily maximum urban heat island intensity (UHIImax) based on routine meteorological data and basic urban properties. The applicability of equation, previously proposed by European scholars, was evaluated based on Local Climate Zone (LCZ) scheme by a long-term temperature observation experiment conducted in Guangzhou. Overall, the underestimation of UHIImax was caused by LCZ1,2,3,4, in which the morphological parameters were outside the application range of the original equation. Then, a revised equation was proposed by adding the impervious surface fraction (ISF) in morphological parameters based on the spatiotemporal variance of UHII for different LCZ. The revised equation was evaluated against a year dataset and revealed a higher accuracy than the original one with a decrease of RMSE and MEAE at 0.4K, 0.15K, an increase of dr at 0.1. Moreover, the efficiency of the equations for all the seasons and LCZs were elucidated. In summary, the results can be used as a tool for monitoring the development of UHI in outdoor temperature studies.

The Role of Turbulent Coherent Structures on Microalgal Mixing for Nutrient Removal in Jet and Paddlewheel Raceway Ponds

Outdoor studies were conducted on microalgae cultures in two raceway ponds (kept in constant motion with either jet or paddlewheel) with a flatbed to treat anaerobic digestion piggery effluent and to observe the characteristics of turbulence on microalgal mixing and growth. Acoustic Doppler Velocimeters (ADV) were deployed to record the instantaneous velocity components and acoustic backscatter as a substitution of microalgae concentration. The present research on microalgal mixing considers the effect of event-based turbulent features such as the widely known ‘turbulent bursting’ phenomenon. This is an important aspect, as turbulent coherent structures can result in microalgal mixing, which can lead to significant changes in microalgal growth. The experimental results presented in this paper of two contrasting environments of jet- and paddlewheel-driven ponds suggested that: (1) turbulent bursting events significantly contributed to microalgal mixing when paddlewheels and jets were used; (2) among four type of turbulent bursting events, ejections and sweeps contributed more to the total microalgal mixing; and, (3) a correlation was revealed using wavelet transform between the momentum and microalgal mixing flux when either jet or paddlewheel were used. Such similarities in jet and paddlewheel raceway ponds highlight the need to introduce turbulent coherent structures as an essential parameter for microalgal mixing studies.