Second-degree Polynomial Function Research Articles

Mathematical modeling for the efficiency function of the Retiro small hydroelectric power plant turbine-generator set

ABSTRACT Many authors use an efficiency constant for the turbine-generator set to calculate energy generation in hydroelectric projects. This often does not reflect reality because the efficiency of this system is relative and is related to the potential of the net head height and the flow of turbine discharge. The present work aims to perform a mathematical modeling for an analysis of the efficiency of the Turbine-Generator Small Hydroelectric Power Plant (SHPP) Retiro. To perform this analysis, a model based on a second-degree polynomial function was employed. A multivariate regression technique was applied by the Least Square Method (LSM) to obtain the coefficients of the function. To verify the behavior of the measured and adjusted data, the Determination Coefficient (R2) of Root Mean Square Error (RMSE) algorithm was applied. The RMSE Mean of 0.022 and the RMSE Std of 0.029 suggest that the second-degree polynomial function is more consistent and stable across different training and validation datasets. The R2 value of 0.993 indicates that 99.3% of the variability in the data is explained by the model. The Omnibus, Durbin-Watson, and Jarque-Bera tests were applied to diagnose potential issues related to normality, autocorrelation, and adequacy, thereby validating the accuracy and significance of the model. The Hessian matrix technique was also used to verify the critical points of the function. The critical point corresponding to a water head of 11.47 meters and a turbine flow of 145.1 m3/s presented the highest operational efficiency. This study allows presenting a turbine efficiency function, its Hill Curve and a generator efficiency function with its corresponding Efficiency Curve. For efficiency analysis in several flow, height and power settings. The technique has proved efficient and can be an applicable tool in energy parameter studies for other hydroelectric projects with the same characteristics as SHPP Retiro.

Digital image analysis of vertebral body L4 and its ossification center in the human fetus.

Using a Siemens-Biograph 128 mCT camera the morphometric analysis of the L4 vertebral body and its ossification center were done in 55human fetuses aged 17 to 30weeks. No sex differences were found. The mean height, transverse and sagittal diameters of L4 vertebral body followed the logarithmic functions: y = -11.797+ 5.208 × ln(age) ± 0.372, y = -23.462 + 9.428 × ln(age) ± 0.702, y = 2.770 + 13.521 × ln(age) ± 1.722, respectively. The mean cross-sectional area of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701. The mean volume of L4 vertebral body followed the second-degree polynomial function: y = -93.983+ 0.385 × (age)² ± 23.707. The mean transverse and sagittal diameters of the ossification center of L4 vertebral body followed the natural logarithmic function: y = -27.106 + 10.178 × ln(age) ± 0.769 and y = -13.345 + 5.458 × ln(age) ± 0.424, respectively. The mean cross-sectional area and the volume of the ossification center of L4 vertebral body followed the linear function: y = -30.683 + 1.976 × age ± 2.701 and y = -43.214 + 2.760 × age ± 4.085, respectively.

Rethinking Income Inequality: A Search for the Optimal Distribution

The United Nations’ ambitious 2030 Agenda, adopted in September 2015, outlines 17 Sustainable Development Goals (SDGs) with the overarching aim of eradicating poverty and hunger. This agenda represents an unprecedented opportunity to address global challenges. However, one crucial aspect, achieving an appropriate level of income disparity (income inequality), remains a significant hurdle for both academics and policymakers. This research gap necessitates a deeper exploration of the theoretical underpinnings of an optimal income distribution for a given population size. This study delves into this under-researched area by analysing the World Bank’s data on population size and the Gini coefficient (a metric for income inequality) for 103 countries (most recent year data available, up to 2023). The analysis employs regression techniques to unveil the relationship between the Gini coefficient and the natural logarithm of population size. The findings suggest a non-linear association, best characterized by a second-degree polynomial function. This implies that the relationship between population size and optimal income distribution is not a simple linear one. Furthermore, the estimated results indicate that the majority of countries in the sample exhibit Gini coefficients that deviate significantly from their theoretically optimal levels. This finding presents valuable insights for policymakers as they design and implement public policies aimed at achieving a more equitable income distribution. The subsequent section delves into a detailed case study of India, analysing its Gini coefficient and the extent of its deviation from the estimated optimal level.

Parabola or second-degree polynomial function exploration in initial teacher training: Integrating intuition and didactic situations

This work is the result of a master’s investigation in Brazil, which discusses the teaching of the parabola in the initial training of mathematics teachers. Our theoretical framework addresses the relationship between intuition and the dialectics of the theory of didactic situations, which supports the analysis of the results of this study Its objective was to identify and register categories of intuitive reasoning manifested by the subjects when solving a didactic situation involving the parabola with GeoGebra software contribution. The methodology adopted was didactic engineering, experimented with eight students in initial training at a Brazilian public university, among 6<sup>th</sup> and 9<sup>th</sup> undergraduate semesters. The posterior analysis and validation allowed us to verify the need to discuss the parabola, articulating its geometric, algebraic, and analytical views, as well as to reinforce the importance of its teaching with the use of technology.

Evaluation of five models for constructing forest NPP–age relationships in China based on 3121 field survey samples

Abstract. Forest net primary productivity (NPP), representing the net carbon gain from the atmosphere, varies significantly with forest age. Reliable forest NPP–age relationships are essential for forest carbon cycle modeling and prediction. These relationships can be derived from forest inventory or field survey data, but it is unclear which model is the most effective in simulating forest NPP variation with age. Here, we aim to establish NPP–age relationships for China's forests based on 3121 field survey samples. Five models, including the semi-empirical mathematical (SEM) function, the second-degree polynomial (SDP) function, the logarithmic (L) function, the Michaelis–Menten (M) function, and the Γ function, were compared against field data. Results of the comparison showed that the SEM and Γ functions performed much better than the other three models, but due to the limited field survey samples at old ages, the Γ function showed a sharp decrease in NPP (decreased to almost zero) at old ages when building some forest NPP–age curves, while SEM could capture the variations in forest NPP at old ages reasonably well. Considering the overall performance with currently available forest field survey samples, SEM was regarded as the optimal NPP–age model. The finalized forest NPP–age curves for five forest types in six regions of China can facilitate forest carbon cycle modeling and future projection by using the process-based Integrated Terrestrial Ecosystem Carbon (InTEC) model in China and may also be useful for other regions.

Experimental and Numerical Evaluation of Solar Receiver Heat Losses of a Commercial 9 MWe Linear Fresnel Power Plant

Evaluating the heat losses of linear Fresnel concentrator (LFC) receivers is crucial for determining plant efficiency and managing the flow rate in solar lines. This becomes particularly significant when operating in direct steam generation to manage the steam quality at the line outlet. In general, the LFC receiver heat losses are determined experimentally on prototype systems to control the inlet condition or numerically using 3D computational fluid dynamics models or 1D mathematical models. The originality of this work is in reporting the study of heat losses of a commercial 9 MWe solar Fresnel power plant without impacting its electricity production. The experimentally measured receiver’s linear heat losses were found to be well represented by a second-degree polynomial function of the difference between the inlet/outlet fluid temperature average and the ambient temperature. Finally, to express the strong influence of wind speed on the receiver heat losses, a 1D single-phase model was developed and adapted to include the current receiver degradation. To conclude, the model was validated by comparing the experimental and theoretical results. Based on this comparison, it can be concluded that the model accurately predicts experimental heat losses with an acceptable uncertainty of ±30%, regardless of the wind velocity.

Adenine’s band strength at cryogenic temperatures

Infrared observations of the interstellar medium have unveiled the existence of numerous solid-phase molecules. The recent detection of uracil within the (162173) Ryugu asteroid has opened new prospects for the discovery of additional compounds, including nitrogenous bases, in the near future. To facilitate the comprehension, identification, and observation of these substances within astrophysical environments, precise measurements of their infrared band strengths are crucial. In this study, we present the outcomes of laboratory experiments conducted to investigate the behavior of adenine at various temperatures. The measured band strength from 3600 to 1970 cm−1 was determined to be 3.21⋅10−16 cm molecule−1. Additionally, as the temperature decreased, its behavior exhibited a well-fitted second-degree polynomial function. Notably, the experiments indicated no permanent phase changes or hysteresis during the cool-down and warm-up processes, further elucidating the thermal properties of adenine.

Mathematical Modeling of Eyebrow Curvature.

The aim of the study is to describe a mathematical model for analyzing eyebrow curvature that can be applied broadly to curvilinear facial features. A total of 100 digital images (50 men, 50 women) were obtained from standardized headshots of medical professionals. Images were analyzed in ImageJ by plotting either 8 or 15 points along the inferior-most row of contiguous brow cilia. A best-fit curve was automatically fit to these points in Microsoft Excel. The second derivative of the second-degree polynomial and a fourth-degree polynomial were used to evaluate brow curvature. Both techniques were subsequently compared with each other. A second-degree polynomial and fourth-degree polynomial were fit to all eyebrows. Plotting 15 points yielded greater goodness-of-fit than plotting 8 points along the inferior brow and allowed for more sensitive measurement of curvature across all images. A fourth-degree polynomial function provided a closer fit to the eyebrow than a second-degree polynomial function. This method provides a simple and reliable tool for quantitative analysis of eyebrow curvature from images. Fifteen-point plots and a fourth-degree polynomial curve provide a greater goodness-of-fit. The authors believe the described technique can be applied to other curvilinear facial features and will facilitate the analysis of standardized images.

Оцінка молекулярної мішені адемолу методом хемоінформатики

Актуальність. Глутаматна ексайтотоксичність та внутрішньочерепна гіпертензія являють собою потенційні мішені щодо можливих розробок патогенетичної терапії уражень мозку, зокрема тих, що асоційовані з високими значеннями внутрішньочерепного тиску. Мета. Методами хемоінформатики обґрунтувати внутрішньовенне застосування адемолу, виявити здатність адемолу блокувати β-адренорецептори, а також за критеріями лікоподібності та біодоступності оцінити можливість його проходження через гематоенцефалічний бар’єр (ГЕБ). Матеріали та методи. Всі обчислення молекулярних дескрипторів були зроблені за допомогою програмного комплексу SIB Swiss Institute of Bioinformatics, розрахункової платформи та Molinspiration Cheminformatics v2016.09, доступних on-line. Результати. Молекулярна маса адемолу не перевищує 500, середній показник ліпофільності розрахований за допомогою програмного комплексу [5], знаходиться для наведених сполук у прийнятному діапазоні. Для адемолу величина LogP дорівнює 2,736, що вище, ніж у ремантадину (2,456), однак нижче, ніж у пропранололу (2,967). Визначено загальну площу полярних поверхонь молекул (TPSA), що розраховується на основі методики, опублікованої Ertl et al. [6] у вигляді внесків суми площин атомів О та N та інших, у складі функціональних груп полярних фрагментів. Для предикації проникнення адемолу через ГЕБ використали розраховані in silico дескриптори — усереднену ліпофільність, що виявилася близькою до описаного раніше коефіцієнту ліпофільності у суміші октанолу та фосфатного буфера [9], та TPSA. Кореляція афінітету (LogKi, nM) з полярністю для відомих β-адреноблокаторів та адемолу описується як параболічна поліноміальна функція другого порядку. Висновки. Побудовано модель кореляції афінітету від ліпофільності для ряду β-адреноблокаторів та передбачено афінність адемолу, що наближається до високоафінних неселективних β-адреноблокаторів.

Novel Approach for Design of Merging and Diverging Length at Toll Plazas: A Case Study

Traffic operations at toll plazas are influenced by the merging and diverging behavior of vehicles near the toll plaza in the flare area. Proper guidelines for the design of merging and diverging sections at toll plazas under mixed traffic conditions are not specified by the Indian Highway Capacity Manual, the Indian Road Congress, or the American Association of State Highway and Transportation Officials. Thus, the present study attempts to develop design criteria for diverging and merging lengths. The field data were collected using the performance-box instrument at Ghoti toll plaza located at National Highway No. 60 in India, operating under mixed traffic conditions. The concept of discretization of speed profile is proposed and applied to segregate sections of the zone of influence into ten equal parts each of 50 m length. The statistical test shows that speed has a significant difference between the sections and also in between the different classes of vehicle. Results of the speed-distance plot show that the second-degree polynomial function is the best fit for zone of deceleration and power function for the zone of acceleration. The study revealed that, for 50 km/h approach speed, the minimum diverging and merging distances should be 125.67–308.98 m and 47.93–294.23 m, respectively. The proposed guidelines for merging and diverging length are useful for the design of the flare area and to improve operational efficiency and level of service at toll plazas operating under mixed traffic conditions.

Tectonic geomorphology and paleoseismology of the northern East Franklin Mountains fault, El Paso, Texas, USA

The 45 km-long, north-trending East Franklin Mountains Fault lies in the southern Rio Grande rift (Texas). Late Quaternary normal fault scarps up to 20 m high traverse the eastern range front, but also bulge up to 2 km out onto the piedmont in lobes as much as 3.5 km wide. In the lobe areas the range-front fault strand displays no fault scarps, as if displacement has shifted to the piedmont strand since ca. 400 ka. We divide the faulted piedmont alluvial fans into seven age classes (from Middle Pleistocene to Holocene), based on erosional dissection and soil profile development. Piedmont scarps in Qf1 deposits (250–400 ka) range from 18 to 20 m high; in Qf2-3 deposits (65–100 ka), 9–10 m high; and in Qf3-4 deposits (20 ka), 2.7–4 m high (the latest displacement event). Scarp heights underestimate true vertical displacement of the footwall surface, which lies buried beneath younger fan deposits of unknown thickness on the hanging wall. Hanging-wall aggradation also causes variable scarp heights along strike on single-age landforms, with burial thickness a second-degree polynomial function (parabolic) of distance to the nearest active stream. Our paleoseismic trench on a 9.8 m-high scarp exposed evidence for five displacement events in the past 44 ka, the latest three of which had vertical displacements of 3–4 m. Such displacements imply surface ruptures longer than the 26.5 km fault length previously mapped in the USA, indicating rupture extended onto adjacent faults. The minimum long-term slip rate (>11.2 m in 44 ka) is 0.25 mm/yr; over last full seismic cycle (ca. 11–29 ka) it is 0.20–0.21 mm/yr. Optically-stimulated luminescence (OSL) dating shows that fine sand-silt grains in colluvial deposits were not all zeroed during deposition. Single-aliquot dating of quartz grains yielded multiple OSL age peaks, the youngest peaks of which yield a chronology compatible with stratigraphy and soil development in the colluvial wedge sequence.

Systematics of the semimicroscopic proton-nucleus optical potential at low energies relevant for nuclear astrophysics

Astrophysical models studying the origin of the p-nuclei require knowledge of the reaction rates of photodisintegrations and capture reactions. Since experimental data at astrophysically relevant energies are limited, reaction rate calculations rely on Hauser-Feshbach (HF) theory predictions. The HF theory requires nuclear physics input such as masses, level densities, $\gamma$-ray strength functions and proton-nucleus optical potentials (pOMP). The scope of this work is to improve a global semi-microscopic pOMP at energies relevant to the p-process. This is achieved by adjusting the normalization parameters of the OMP to all available proton-capture cross sections measured at low energies. By establishing the systematic behaviour of these parameters, one expects to enhance the predictive power of the pOMP when expanding to mass regions where no data exists. The HF calculations were obtained using TALYS code. The normalization parameters for the real and imaginary central potentials ($\lambda_V$ and $\lambda_W$) were adjusted to fit the proton data in the energy range where the cross-section are independent of the other nuclear inputs. Results show that the $\lambda_V$ parameter has a strong mass dependence that can be described by a second-degree polynomial function for A $\leq$ 100 and an exponential increase for 100 < A < 162. Though variations of the $\lambda_W$ have a smaller effect on the calculations, a global increase by 50$\%$ improves the results for certain nuclei without affecting the rest of the cases. The resulting adjustment functions were obtained by fitting all suitable proton data and can be used with reasonable confidence to generate the global semi-microscopic pOMP for nuclei in the medium to heavy mass region. For better statistics, more low-energy (p,$\gamma$) cross section data are needed for heavier nuclei with mass A $>$ 100.

Determination of the critical micelle concentration and thermodynamic parameters of phenylcarbamic acid derivatives using a fluorescence method

Critical micelle concentration (CMC) values of 1-[3-(2-alkoxyphenylcarbamoyloxy)-2-hydroxypropyl]-4-(4-fluorophenyl)piperazin-1-ium-chlorides (alkoxy = methoxy to propoxy; 6a–c) were determined by a fluorescence method using pyrene as a probe over a temperature interval T = 293.15–313.15 K. The dependence of CMC on T turned out forming the U-shape. The curve was drawn by fitting of observed values using a second-degree polynomial function and so-called power-law equation, minimum of the curve was observed at T = 298.15 K. Thermodynamic parameters of micellization, i.e., molar Gibbs energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°), respectively, were calculated according to a phase separation model. Following the observations, the enthalpy (ΔH°) and entropy contributions (−TΔS°) to the molar Gibbs energy (ΔG°) were calculated. It was found that contribution of enthalpy increased with the increase in temperature, and entropy contribution decreased within chosen range of the temperature. Finally, the enthalpy–entropy compensation and the compensation temperature (Tc) were determined.

Entropy of resilience: Formulism and validation using strained-induced surface wettability study on thin film alloys

To circumvent the lack of interfacial tension data, we introduced a new material thermodynamics property termed as entropy of resilience SR to promote the application of Young’s equation. Derived from Helmholtz free energy analysis, this property relates to a specimen’s reduction in entropy and heat formation process. Moreover, we demonstrate a non-linear entropy-strain relationship, and proposed entropy change can be characterized by tensile tests and water contact angle measurements. Hence, water contact angle change is established as a second-degree polynomial function of strain, validated by surface wetting measurement of intrinsically strained thin film NiTi. Accordingly, a ∼60° increase in water contact angle can be interpreted as an entropy reduction of 38.61 Jkg−1K−1. This newly defined concept of entropy of resilience corresponds to a new paradigm shift wherein entropy is regarded as the predominate thermodynamic driver of surface wetting.

Volumetric Flow Observer For A Pumping Unit Without Backpressure With Induction Electric Drive

The article describes the construction of a volumetric fluid supply observer in pumping systems. The electric drive of the pump unit uses an induction motor with a squirrel-cage rotor. The rotation speed of the electric motor is adjustable. A centrifugal pump is used to pressurize a pipeline. Requirements for the automation level of pumping units are growing, so the research topic is relevant. When constructing the observer, the double squirrel cage induction motor model in a fixed coordinate system is used. The impeller rotation speed and the pump resistance moment were estimated based on the Luenberger observer. The observer is used to identify the volume flow. It is based on a centrifugal pump model using approximating coefficients of a Second-Degree Polynomial function. The article provides the dynamic characteristics of the reference model and observer. As a studies result, an error in the steady state operating mode of 1% was determined.

Feasibility study of a proton fluence monitor for LEO-Nanosatellite missions based on displacement damage induced in GaAs-LED

High-energy protons trigger irreparable displacement damage (DD) in unbiased Gallium Arsenide (GaAs) Light-Emitting Diode GaAs-LED (GAL) . The DD is caused by non-ionizing-energy-loss (NIEL) process and results in reduction of light emission of the GAL when connected to a power source. Based on this finding a lightweight, low current consuming proton detector for space applications was developed. A commercial off the shelf (COTS) yellow GAL optically coupled to a Light-to-Frequency converter chip (LFC) made the basic assembly of the proposed proton detector. The device was calibrated using selected GAL samples irradiated with a 180 MeV proton beam from a proton-therapy medical cyclotron to 2, 10, 50, 100, 200 and 300 Gy dose levels. The light output of the GAL was measured with the detector assembly and presented as frequency (kHz). Protons of energy distribution between 100 keV to ∼500 MeV are trapped in the inner-shell of the Van Allen belt (VAB) surrounding the earth, whereas the intensity of trapped electrons (Emax ∼10 MeV) remains insignificant. The GAL light output data (frequency) was fitted with a second-degree polynomial function of imparted proton dose (∼ number of protons). The results were parameterized for widely used NASA radiation belt models AP8-Max and AP8-Min using the proton NIEL distribution in Gallium Arsenide (GaAs). Spacecrafts, in particular Nanosatellites operating in low earth orbit (LEO) environment are primarily exposed to those trapped protons in the VAB . Nanosatellites endure severe radiation exposure while passing through the South Atlantic Anomaly (SAA) region. The footprint, mass and average current consumption of the proton detector was 0.027 cm2, 0.28 g and 2.5 mA respectively. The highest detectable level proton fluence (protons⋅cm−2) was evaluated to be 1.17× 109 and 1.01× 109 for AP8-Max and AP8-Min models respectively. Hence the proposed GAL based radiation detector is only suited for proton fluence monitoring on board LEO-Nanosatellites (NanoSat) of short lifetime, usually 6–18 months.

Temperaturni model fotonaponskog modula

The primary purpose of this study is to create a thermal model of a photovoltaic module which is usable under real climatic conditions in the Central Europe region. The system for temperature measurements of the photovoltaic module was designed and built at the Department of Physics SUA in Nitra. The climate data utilized in the present study were obtained from a weather station. The measurements were performed during the summer on PV modules. The results obtained indicate that the response of the module temperature is dynamic with changes in irradiance and module temperature, particularly during the periods of fluctuating irradiance. Mathematical descriptions of the obtained time-temperature and time-irradiance relations were made on the basis of the experimental results obtained. A second-degree polynomial function was established for every graphical relation obtained with relatively high coefficients of determination. The temperature model of PV modules was generated after fitting the experimental results to real dependencies and correlation analysis values.

Dynamic forecasting of individual cow milk yield in automatic milking systems

Accurate forecasting of dairy cow milk yield is useful to dairy farmers, both in relation to financial planning and for detection of deviating yield patterns, which can be an indicator of mastitis and other diseases. In this study we developed a dynamic linear model (DLM) designed to forecast milk yields of individual cows per milking, as they are milked in milking robots. The DLM implements a Wood's function to account for the expected total daily milk yield. It further implements a second-degree polynomial function to account for the effect of the time intervals between milkings on the proportion of the expected total daily milk yield. By combining these 2 functions in a dynamic framework, the DLM was able to continuously forecast the amount of milk to be produced in a given milking. Data from 169,774 milkings on 5 different farms in 2 different countries were used in this study. A separate farm-specific implementation of the DLM was made for each of the 5 farms. To determine which factors would influence the forecast accuracy, the standardized forecast errors of the DLM were described with a linear mixed effects model (lme). This lme included lactation stage (early, middle, or late), somatic cell count (SCC) level (nonelevated or elevated), and whether or not the proper farm-specific version of the DLM was used. The standardized forecast errors of the DLM were only affected by SCC level and interactions between SCC level and lactation stage. Therefore, we concluded that the implementation of Wood's function combined with a second-degree polynomial is useful for dynamic modeling of milk yield in milking robots, and that this model has potential to be used as part of a mastitis detection system.

Nonlinear analysis of VCO jitter generation using Volterra series

PurposeCharge pump phase locked loops (CPPLLs) are nonlinear systems as a result of the nonlinear behavior of voltage-controlled oscillators (VCO). This paper aims to specify jitter generation of voltage controlled oscillator phase noise in CPPLLs, by considering approximated practical model for VCO.Design/methodology/approachCPPLL, in practice, shows nonlinear behavior, and usually in LC-VCOs, it follows second-degree polynomial function behavior. Therefore, the nonlinear differential equation of the system is obtained which shows the CPPLLs are a nonlinear system with memory, and that Volterra series expansion is useful for such systems.FindingsIn this paper, by considering approximated practical model for VCO, jitter generation of voltage controlled oscillator phase noise in CPPLLs is specified. Behavioral simulation is used to validate the analytical results. The results show a suitable agreement between analytical equations and simulation results.Originality/valueThe proposed method in this paper has two advantages over the conventional design and analysis methods. First, in contrast to an ideal CPPLL, in which the characteristic of the VCO’s output frequency based on the control voltage is linear, in the present paper, a nonlinear behavior was considered for this characteristic in accordance with the real situations. Besides, regarding the simulations in this paper, a behavior similar to the second-degree polynomial was considered, which caused the dependence of the produced jitter’s characteristic corner frequency on the jitter’s amplitude. Second, some new nonlinear differential equations were proposed for the system, which ensured the calculation of the produced jitter of the VCO phase noise in CPPLLs. The presented method is general enough to be used for designing the CPPLL.

Measurement of Pesticide Drift from Unmanned Aerial Vehicle Application to a Vineyard

Abstract. Unmanned aerial vehicles (UAVs) are now being used to perform commercial pesticide applications in California, but little information is available regarding the amount of pesticide drift resulting from these applications. The physical dimensions and operating speed of UAVs differ substantially from those of manned aircraft and fall outside the validated range of spray dispersion models. This study measured spray drift from a 0.84 ha aerial pesticide application of imidacloprid performed with a Yamaha R-Max II UAV over a Napa Valley vineyard. Downwind deposition samples, in-swath deposition samples, and downwind air samples were collected up to 48 m downwind of the application field. In-swath deposition samples measured approximately 57% of the target rate, while downwind drift deposition decreased from approximately 0.4% at 7.5 m downwind to 0.03% at 48 m downwind. All air samples were below the method detection limit. A drift deposition curve fitted to measured ground deposition using a log-log second-degree polynomial function yielded an R2 value of 0.985. An estimated 0.28% to 0.54% of applied material was lost as drift out to 50 m downwind of the field edge based on ground deposition measurements, 82% of which deposited within the first 7.5 m downwind. Uncertainty in mass accountancy and deposition measurements is discussed, with sources of error including obstructions in the downwind measurement area, low collection efficiency of the sampling media, a high coefficient of variation of spray deposition in the treatment field, and possible photodegradation of the tracer material. Keywords: Aerial application, AGDISP, Pesticide deposition, Pesticide drift, Remotely piloted aircraft, UAV, Unmanned aerial vehicle, Vineyard.