Effective Index Research Articles

Strong Coupling of Resonant Metasurfaces with Epsilon-Near-Zero Guided Modes.

We study, both theoretically and experimentally, strong interaction between a quasi-bound state in the continuum (QBIC) supported by a resonant metasurface with an epsilon-near-zero (ENZ) guided mode excited in an ultrathin ITO layer. We observe and quantify the strong coupling regime of the QBIC-ENZ interaction in the hybrid metasurface manifested through the mode splitting over 200 meV. We also measure experimentally the resonant nonlinear response enhanced near the ENZ frequency and observe the effective nonlinear refractive index up to ∼4 × 10-13 m2/W in the ITO-integrated dielectric nanoresonators, which provides a promising platform for low-power nonlinear photonic devices.

Mechanisms of investors’ bounded rationality and market herding effect by the stochastic Ising financial model

The widespread herding effect prevalent in China’s stock market is caused by investors’ bounded rationality behavior. However, the underlying mechanisms are not fully understood. This article aims to use the stochastic Ising financial model, which explains this problem from the perspective of Econophysics. The probability density function and power-law distribution of return data simulated by the stochastic Ising financial model show sharp peaks and fat tails, similar to the stylized facts of real Chinese stock market data. Further, we use this financial model to simulate herding behavior in the market. The results show that when the degree of investor irrationality (represented by β) increases, the Herd Effect Index (HERDI) also rises. When β exceeds a critical point, the HERDI index fluctuates more violently. Through empirical analysis, we find that there is an interactive relationship between investors’ bounded rational behavior and market herding effects, and this model can effectively explain these two phenomena.

An Integrated CREAM for Human Reliability Analysis Based on Consensus Reaching Process under Probabilistic Linguistic Environment

Human reliability analysis (HRA) is widely used to evaluate the impact of human errors on various complex human–machine systems for enhancing their safety and reliability. Nevertheless, it is hard to estimate the human error probability (HEP) in reality due to the uncertainty of state assessment information and the complex relations among common performance conditions (CPCs). In this paper, we aim to present a new integrated cognitive reliability and error analysis method (CREAM) to solve the HRA problems under probabilistic linguistic environment. First, the probabilistic linguistic term sets (PLTSs) are utilized to handle the uncertain task state assessments provided by experts. Second, the minimum conflict consensus model (MCCM) is employed to deal with conflict task state assessment information to assist experts reach consensus. Third, the entropy weighting method is used to determine the relative objective weights of CPCs. Additionally, the CPC effect indexes are introduced to assess the overall effect of CPCs on performance reliability and obtain the HEP estimation. Finally, the reliability of the proposed CREAM is demonstrated via a healthcare practical case. The result shows that the new integrated CREAM can not only effectively represent experts’ uncertain task state assessments but also determine more reliable HEP estimation in HRA.

Urban exodus or suburbanisation? Medium-term COVID-19 pandemic impacts on internal migration in Japan

The COVID-19 pandemic has profoundly affected internal migration patterns worldwide. Most previous studies have reported on pandemic-induced changes in internal migration using data from 2020 and 2021. Therefore, little is known about the pandemic’s medium-term impact. To address this gap, this study investigated an annual series of migration patterns from 2019 to 2023 in Japan. At the municipal level, relationships between net migration rates and population density indicated that the urbanisation trend became weak in 2020, compared to that in 2019, and it was the weakest in 2021. The urbanisation degree became stronger in 2023, increasing to the level in 2020. Using annual inter-municipal migration flows, this study then investigated changes in migration flows to/from and within three major metropolitan areas (Tokyo, Nagoya, and Osaka). The changes in sizes of these flows and migration effectiveness index suggested that the pandemic had the largest impact in the Tokyo metropolitan area, among the three areas, and it stimulated intra-metropolitan migration as suburbanisation, rather than net out-migration as ‘urban exodus’, in Japan. The overall results indicated that the pandemic had the largest impact in 2021, which got smaller as the migration patterns recovered to the pre-pandemic ones in 2023.

The Adaptation of the Communicative Effectiveness Index (CETI) into Greek: A Reliability and Validity Study.

The Communicative Effectiveness Index (CETI) is an informant rating scale designed to measure changes in functional communication in people with aphasia (PWA) from the carer's perspective. It offers a comprehensive view of aphasia's impact on everyday communication situations, aiding clinicians in designing personalized intervention plans. The aim of this study was to translate and adapt the CETI into Greek (CETI-GR) and validate its psychometric properties. The CETI-GR was translated into Greek using back-translation. A pilot and a content validity study ensured its acceptability. The study involved 30 people with aphasia and 30 carers. The CETI-GR's psychometric properties were evaluated, including internal consistency, test-retest reliability, inter-rater reliability, and validity measures. The CETI-GR demonstrated excellent internal consistency (Cronbach's α > 0.95) and excellent inter-rater reliability (ICC ≥ 0.93). Excellent consistency was revealed when testing the CETI responses given only by PWA (α = 0.91) versus their carers (α = 0.97). Test-retest reliability was high (ICC = 0.88). Significant correlations between the CETI-GR and measures of language severity, functional communication, and quality of life supported convergent validity. The CETI-GR is a reliable tool for assessing functional communication in chronic aphasia. Its Greek adaptation enhances aphasia rehabilitation, enabling person-centered care and improving the quality of life for people with aphasia and carers.

Unmanned Aerial Vehicle-Measured Multispectral Vegetation Indices for Predicting LAI, SPAD Chlorophyll, and Yield of Maize

Predicting crop yield at preharvest is pivotal for agricultural policy and strategic decision making. Despite global agricultural targets, labour-intensive surveys for yield estimation pose challenges. Using unmanned aerial vehicle (UAV)-based multispectral sensors, this study assessed crop phenology and biotic stress conditions using various spectral vegetation indices. The goal was to enhance the accuracy of predicting key agricultural parameters, such as leaf area index (LAI), soil and plant analyser development (SPAD) chlorophyll, and grain yield of maize. The study’s findings demonstrate that during the kharif season, the wide dynamic range vegetation index (WDRVI) showcased superior correlation coefficients (R), coefficients of determination (R2), and the lowest root mean square errors (RMSEs) of 0.92, 0.86, and 0.14, respectively. However, during the rabi season, the atmospherically resistant vegetation index (ARVI) achieved the highest R and R2 and the lowest RMSEs of 0.83, 0.79, and 0.15, respectively, indicating better accuracy in predicting LAI. Conversely, the normalised difference red-edge index (NDRE) during the kharif season and the modified chlorophyll absorption ratio index (MCARI) during the rabi season were identified as the predictors with the highest accuracy for SPAD chlorophyll prediction. Specifically, R values of 0.91 and 0.94, R2 values of 0.83 and 0.82, and RMSE values of 2.07 and 3.10 were obtained, respectively. The most effective indices for LAI prediction during the kharif season (WDRVI and NDRE) and for SPAD chlorophyll prediction during the rabi season (ARVI and MCARI) were further utilised to construct a yield model using stepwise regression analysis. Integrating the predicted LAI and SPAD chlorophyll values into the model resulted in higher accuracy compared to individual predictions. More exactly, the R2 values were 0.51 and 0.74, while the RMSE values were 9.25 and 6.72, during the kharif and rabi seasons, respectively. These findings underscore the utility of UAV-based multispectral imaging in predicting crop yields, thereby aiding in sustainable crop management practices and benefiting farmers and policymakers alike.

Improving VAT collection efficiency through policy design and compliance improvement and moderated by control of corruption

Value Added Tax (VAT) is increasingly relied upon by an increasing number of economies, as shown by the global trend of increasing standard tax rates, but raises questions about the efficiency of its levy. This study revisits the determinants of VAT collection efficiency by using the C-efficiency ratio approach. Using a dataset of countries in the SEAO region (East Asia, Southeast Asia, and the Pacific), this study was performed quantitatively using a panel data regression analysis. The results show that the government effectiveness index is unlikely to be an appropriate proxy for the compliance gap. In terms of the policy gap, policy changes by increasing the standard VAT rate might reduce the C-efficiency ratio, whereas lowering the VAT registration threshold might not improve the C-efficiency ratio. However, the control of corruption index as a moderating variable could antagonize the negative effect of the VAT standard rate on the C-efficiency ratio. This finding corroborates previous studies and encourages discussion to find variables that better measure compliance and policy gap.

3D Bulk Metamaterials with Engineered Optical Dispersion at Terahertz Frequencies Utilizing Amorphous Multilayered Split-Ring Resonators.

A 3D bulk metamaterial (MM) containing amorphous multilayered split-ring resonators is proposed, fabricated, and evaluated. Experimentally, the effective refractive index is engineered via the 3D bulk MM, with a contrast of 0.118 across the frequency span from 0.315 to 0.366 THz and the index changing at a slope of 2.314 per THz within this frequency range. Additionally, the 3D bulk MM exhibits optical isotropy with respect to polarization. Moreover, the peak transmission and optical dispersion are tailored by adjusting the density of the split-ring resonators. Compared to reported conventional approaches for constructing bulk MMs, this approach offers advantages in terms of the potential for large-scale manufacturing, the ability to adopt any shape, optical isotropy, and rapid optical dispersion. These features hold promise for dispersive optical devices operating at THz frequencies, such as high-dispersive prisms for high-resolution spectroscopy.

Age-adjusted Charlson Comorbidity Index as an effective tool for the choice between simultaneous or staged bilateral total knee arthroplasty.

The choice between simultaneous and staged bilateral total knee arthroplasty (BTKA) remains controversial. Age-adjusted Charlson Comorbidity Index(CCI) is a promising tool for risk-stratification. We aimed to compare the outcomes between patients who underwent simultaneous and staged BTKA, stratified by age-adjusted CCI scores. We conducted this retrospective, single-surgeon case series from 2010 to 2020. This study consisted of 1558 simultaneous BTKA and 786 staged BTKA procedures. The outcome domains included 30-day and 90-day readmission and 1-year reoperation events. We performed multivariate regression analysis to compare the risk of readmission and reoperation following simultaneous and staged BTKA. Other factors included age, sex, body mass index, diabetes mellitus, rheumatoid arthritis, smoking, receiving thromboprophylaxis and blood transfusion. The rates of 30-day, 90-day readmission and 1-year reoperation following simultaneous BTKA was 1.99%, 2.70% and 0.71%, respectively. The rates of 30-day, 90-day readmission and 1-year reoperation following staged BTKA was 0.89%, 1.78% and 0.89%, respectively. For patients with age-adjusted CCI ≥ 4 points, simultaneous BTKA was associated with a higher risk of 30-day (aOR:3.369, 95% CI:0.990-11.466) and 90-day readmission (aOR:2.310, 95% CI:0.942-5.668). In patients with age-adjusted CCI ≤ 3 points, the risk of readmission and reoperation was not different between simultaneous or staged BTKA. Simultaneous BTKA was associated with an increased risk of short-term readmissions in patients with age-adjusted CCI ≥ 4 points but not in those with age-adjusted CCI ≤ 3 points. Age-adjusted CCI can be an effective index for the choice between simultaneous and staged BTKA procedures.

Foam density mapping via THz imaging

Plastic foams, near-ubiquitous in everyday life and industry, show properties that depend primarily on density. Density measurement, although straightforward in principle, is not always easy. As such, while several methods are available, plastic foam industry is not yet supported with a standard technique that effectively enables to control density maps. To overcome this issue, this paper proposes Terahertz (THz) time-of-flight imaging using normal reflection measurements as a fast, relatively cheap, contactless, non-destructive and non-dangerous way to map plastic foam density, based on the expected relationship between density and refractive index. The approach is demonstrated in the case of polypropylene foams. First, the relationship between the estimated effective refractive index and the polypropylene foam density is derived by characterizing a set of carefully crafted samples having uniform density in the range 70–900 kg/m3. The obtained calibration curve subtends a linear relationship between the density and the refractive index in the range of interest. This relationship is validated against a set of test samples, whose estimated average densities are consistent with the nominal ones, with an absolute error lower than 10 kg/m3 and a percentage error on the estimate of 5%. Exploiting the calibration curve, it is possible to build quantitative images depicting the spatial distribution of the sample density. THz images are able to reveal the non-uniform density distribution of some samples, which cannot be appreciated from visual inspection. Finally, the complex spatial density pattern of a graded foam sample is characterized and quantitatively compared with the density map obtained via X-ray microscopy. The comparison confirms that the proposed THz approach successfully determines the density pattern with an accuracy and a spatial scale variability compliant with those commonly required for plastic foam density estimate.

Frequency tunable mid-infrared split ring resonators on a phase change material

Meta-surfaces arrays are 2D meta-materials with a periodicity below the diffraction limit that permits to obtain homogeneous layers of resonant effective refractive index. In this work we present an analytical model that describes the electromagnetic behavior of meta-surfaces constituted by split-ring resonators (SRR). SRR resonance frequency can be adjusted by choosing their geometric parameters and the materials they are made of. Their deposition on a phase change material enables an optical modulation of resonance peak during the phase transition. We demonstrate a mid-infrared tunable SRR meta-surface using Vanadium dioxide (VO2) as phase change material deposited on III-V semiconductors by low temperature pulsed laser ablation technique. The presented measurements exhibit a maximum of 100 cm−1 resonance shift. This result is very promising for the conception of monolithic, robust, compact, frequency tunable III-V based devices in the mid-infrared.

Prebiotic Chemistry and Sepiolite: A Density Functional Theory Approach

In this study, the molecular interactions of sepiolite, a biocompatibility clay mineral with known as biomaterial, and purine and pyrimidine molecules forming the bases of DNA and RNA molecules were modeled by Density Functional Theory. In addition to the geometry optimization, interaction energy, bond critical point, and electrostatic potential calculations revealed that essential molecules for our source of life interact with the basal surface of the clay. For example, the best interaction energies between bases / sepiolite were found to be -127.47, -121.35 kJ / mol for guanine and cytosine, respectively. Looking at the modeling results, one of the most important factors affecting the interaction energies is H-bond. In order to reveal this, bond critical points analyze were performed and it was computed that a large amount of intermolecular interaction energies came from H-bonds. For example, it has been calculated that close to 70% of the total energy in the guanine/TOT model is from H-bonds. Besides, this value of the cytosine/TOT model was found to be around 72%. The most effective indexes in these two models are 145 and 135, and the H-bond energies were recorded as -22.41 and 31.41 kJ/mol, respectively. Considering all the analyzes run, it can be concluded that the basal surfaces of the sepiolite are a suitable host for the nitrogenous bases, which are the main sources of life.

Research on ecological restoration and green reclamation technology of goaf in phosphorus mines

The subsidiary of Yunnan Phosphate Group Co., Ltd., Kunyang Phosphate Mine’s mining area is the subject of study. The mining of open-pit phosphate mines has caused significant damage to the ecological environment. Therefore, carrying out ecological restoration and green reclamation of the ecosystem in the mining area has become the top priority for current development. This article establishes an evaluation system for ecological restoration indicators, selecting four indicators including vegetation coverage, soil and water conservation, restoration of native plants, and Plant Species Diversity Index to assess the effects of ecological restoration and green reclamation of phosphate mines. The techniques of reconstructing soil ecological structure using phosphate tailings substrate and improving acidic soil with soil conditioner and calcium-magnesium phosphate compound fertilizer were applied. A series of other measures were taken, including: drafting scientific ecological restoration plans; employing physical, chemical, and biological methods for ecological restoration and green reclamation; selecting suitable plant species for planting; enhancing planting techniques; and strengthening post-restoration ecological monitoring and regulation. After ecological restoration and green reclamation, the Ecological Remediation Effect Index (EREI) for the years 2020, 2021, and 2022 were 48.40, 87.38, and 93.23 respectively, indicating significant improvement in the ecological environment. Furthermore, the difficulties encountered during the ecological system restoration process of the mine and the future development directions were summarized, providing practical and guiding significance for ecological restoration and green reclamation of abandoned mining areas both domestically and internationally.

Factors influencing IoT adoption for sustainable facilities management in Saudi Arabia: a stakeholder assessment

PurposeThis paper evaluates the factors influencing the utilization of the Internet of Things (IoT) for sustainable facilities management (SFM) practices in Saudi Arabia.Design/methodology/approachA mixed approach, combining a literature review, pilot-testing and questionnaire survey, was adopted to evaluate the factors. Twenty-seven factors were identified and grouped into four groups: technical, business and organizational, operational and security and privacy. The questionnaire was distributed to 30 facilities managers and 30 IoT specialists, totaling 60 practitioners, to determine the effect index of each factor. The practitioners' consensus on the ranking of the factors was then determined.FindingsThe study identifies the top-ranking factors as: “Difficulty in ensuring data security and protection,” “Difficulty in ensuring data privacy and confidentiality” and “Limited awareness and understanding of IoT benefits and capabilities.” These factors highlight the challenges to successful IoT implementation in the FM sector. The FM sector could benefit from utilizing IoT while maintaining the security, privacy and effectiveness of building operations by successfully addressing these concerns. A high level of consensus on the ranking of the factors was observed between facilities managers and IoT specialists. This was substantiated by a Spearman’s rank correlation coefficient of 0.79.Originality/valueThis study enriches the literature by combining practical insights from facilities managers with technical expertise from IoT specialists on the factors impacting IoT implementation in the Saudi Arabian FM sector. Beyond academic contributions, it provides practical insights for industry professionals, fostering a culture of knowledge-sharing and guiding future research in this field.

Reducing Left Ventricular Wall Stress through Aortic Valve Enlargement via Transcatheter Aortic Valve Implantation in Severe Aortic Stenosis.

Background: In aortic stenosis, the left ventricle exerts additional force to pump blood through the narrowed aortic valve into the downstream arterial vasculature. Adaptive hypertrophy helps to maintain wall stress homeostasis but at the expense of impaired compliance. Advanced ventricular deformation impacts the extent of functional recovery benefits achieved through transcatheter aortic valve implantation. Methods and Results: Subgroups were stratified based on output, with low-flow severe aortic stenosis defined as stroke volume index <35 mL· m-2. Before intervention, the low-flow subgroup exhibited worse effective orifice area index and arterial and global impedance, along with thinner wall thickness and larger chamber volume marginally. LV performance, including stroke volume index, ventricular elastance, and ventricular-arterial coupling, were notably inferior, consistent with worse adverse remodeling. Although the effective orifice area index was similarly augmented after TAVI, inferior recovery benefits were noted. Persistently higher wall stress and energy consumption were observed, along with poorer ventricular-arterial coupling. These changes in wall stress showed an inverse relationship with alterations in wall thickness and were proportional to changes in dimension and volume. Additionally, they were proportional to changes in left ventricular end-systolic pressure, pressure-volume area, and ventricular-arterial coupling but inversely related to ventricular end-systolic elastance. Conclusions: The study revealed that aortic valve enlargement through transcatheter aortic valve implantation reduces left ventricular wall stress in severe aortic stenosis. The reduced recovery benefits in the low-flow subgroup were evident. Wall stress could serve as a marker of mechanical benefit after the intervention.

Efficient prediction of optical properties in hexagonal PCF using machine learning models

This research explores the use of machine learning (ML) models to forecast optical characteristics in photonic crystal fibers (PCF). Specifically, we focus on a solid core index-guided PCF with a hexagonal cladding arrangement. The primary challenges to PCF propagation analysis and predictions are accuracy, computational error, and time constraints. To address these difficulties, we have specially used ML ensemble models including Decision Tree Regressor (DTR), Random Forest Regressor (RFR), Gradient Boosting Regressor (GBR), eXtreme Gradient Boosting Regression (XGBR), and Bagging Regressor (BR). Model performance is assessed using metrics like Mean Squared Error (MSE) and R-squared (R2) through 10-fold cross-validation. Our key findings show that the GBR model outperforms other models and shows extremely low MSE and outstanding R2 values in predicting effective refractive index (Neff), effective mode area (Aeff), confinement loss, and dispersion. In addition, the study compares the performance of ML models with that of previous works using Artificial Neural Network (ANN), demonstrating improved efficiency in predicting optical characteristics for hexagonal PCFs.

Assessment of apple soluble sugar content by hyperspectral vegetation indexes

Soluble sugar content in apple fruit is a crucial internal quality factor. Rapid and accurate estimation of soluble sugar content in apple fruit is helpful to predicting maturity. However, few studies have used an approach of hyperspectral vegetation indexes for monitoring apple soluble sugar content from ground-based handheld hyperspectral data. This study systematically analyzed the performance of hyperspectral vegetation indexes of apple in estimating the soluble sugar content. The visible and near infrared spectral of apple samples were measured by using a hyperspectral equipment, with the wavelength of 350–2500 nm. Eleven early-ripening apple varieties were collected from orchards located in five provinces of China, and the sugar content of each apple fruit sample was measured using laboratory methods. Two-band combination method was used to identify the effective spectral index. Results showed that the newly developed two-band ratio spectral index R833/R834 (Rλ is the reflectance value at wavelength λ) was recommended as the optimal index for monitoring early-ripening apple soluble sugar content, generated the coefficients of determination, root mean square error (RMSE) and residual prediction deviation (RPD) values between the measured and predicted values of 0.73%, 0.72%, and 1.38%, respectively. Result indicated that the newly developed two-band index R833/R834 can be used to nondestructively determine apple fruit soluble sugar content. The findings can provide insight into the relationship between the optical properties of apple fruit at different wavelengths and soluble sugar content.

Can metals and radionuclides in Shiveluch (Kamchatka) volcanic ash affect human health?

Volcanic eruption is associated with the release of large volumes of pollutants in the environment, which can pose a risk to humans and other living organisms. The elemental and radioisotope composition of ash released during the Shiveluch Volcano eruption in 2023 was analyzed using ICP-MS and low-background gamma spectrometry. The ash consisted of 59% SiO2, 16.7% Al2O3, 5.3% CaO, 4.6 % Na2O, 4.5% Fe2O3, 1.4% K2O, 0.48% TiO2, 0.17% P2O5, 0.15% S, 0.078% MnO and 44 trace elements. Hazard Quotient and Hazard Index were calculated in order to evaluate the potential health risks to children and adults due to exposure to contaminants via inhalation, ingestion, and dermal contact. All values were below the unit, indicating a low probability of non-carcinogenic and cancerogenic risk occurrence in target groups. The average activity concentrations of the natural radionuclides were 350, 12.4 and 4.84 Bq/kg for 40K, 226Ra and 232Th. Radiological indices, including external and internal risk assessment, radium equivalent activity, annual effective dose, gamma index, and excess lifetime cancer risk were calculated to estimate the radiological hazard for the population. The values of all indices were below the recommended safety limits, indicating a low level of hazard for the exposed population.

Swimming ability of the Carybdea marsupialis (Cnidaria: Cubozoa: Carybdeidae): implications for its spatial distribution

AbstractAlthough usually considered part of the plankton, cubozoans are strong swimmers. The aim of this study was to determine the influence of the active swimming ability of the box jellyfish Carybdea marsupialis on the spatial distribution of a well‐studied population in the NW Mediterranean where adults and juveniles do not overlap geographically. To accomplish this, we analyzed the swimming speed, effective velocity, effective displacement index (EDI), and proficiency of 27 individuals with diagonal bell widths (DBWs) ranging from 1.1 to 36 mm. The laboratory analysis utilized conventional video recordings and the video analysis tool Tracker. Mean swimming speed for small juveniles, medium juveniles and adults was 9.7 ± 0.8, 21.9 ± 2.3 and 43.1 ± 1.8 mm s−1 (mean ± se), respectively. Effective velocity was also proportional to size, ranging from 5.0 ± 0.7 to 38.8 ± 3.1 mm s−1 (mean ± se). The calculated EDI for each group was 0.51 ± 0.05, 0.84 ± 0.06 and 0.90 ± 0.05 (mean ± se), respectively. Proficiency showed an inverse trend, from 6.4 ± 0.6 s−1 for the small juveniles to 1.36 ± 0.05 for adults (mean ± se). Comparing the swimming speed results with the local currents obtained from drifting buoys analyzed in the area, adults would be able to swim strongly enough to overcome almost 70% of the currents, whereas the small juveniles would not reach 17%. This would allow larger individuals to select their habitat, while smaller individuals are left dependent on advection. Although experiments adding currents in aquaria would be necessary to confirm these theoretical results, the data obtained would be useful in improving the performance of bio‐mathematical models used to predict jellyfish blooms since, even though the sting of C. marsupialis is non‐fatal, it may produce systemic effects in sensitive swimmers.

The mitigating effect of street trees, urban flora, and the suburban environment on seasonal peak UV indices: A case study from Brisbane, Australia.

Tree shade, particularly shade that obscures direct sunlight near peak periods of midday solar exposure can have a pronounced effect on potentially harmful ultraviolet radiation, and in turn, strongly influence the maximum daily UV index (UVI). In this study, the seasonal influence of tree shade on the UVI is evaluated from 210 hemispherical sky view images collected alongside public walkways and footpaths from 10 residential Brisbane suburbs. The effective sidewalk UV index is calculated underneath planted tree canopies, adjacent residential gardens, buildings and background tree species. Results are presented with respect to seasonal variations in the diurnal solar elevation for each month of the year at Brisbane's latitude. The research also examines the total reduction in UVI due to the presence of individual tree species, showing reductions in the midday UVI of up to 91% of an equivalent unimpeded sky hemisphere when overhead tree canopies are present. Important footpath tree species for peak midday UVI mitigation include Pongamia pinnata, Xanthostemon chrysanthus, Senna siamea, and Libidibia ferrea. The planting and maintenance of existing tree species already growing alongside residential Brisbane streets will improve the shade characteristics of suburbs and enhance UV protection for local residents.