Windy Day Research Articles

Symbol and Tradition in the Painting of Eudochia Robu

Being an artist with deep visions, Eudochia Robu makes extensive use of symbols in her creation, in which no object appears by chance. Decoding them gives it depth. E. Robu is in the list of the most valuable artists in the republic. One of the symbols that has priority in the artist’s painting is that of the angel, which every time comes with a new social message. The angel appears engaged in various human activities: riding a bicycle, leswinging on the swing, sleeping: “Angel on a bicycle”, “Angel on a donkey”, “Angel and birds”, “Angel with white cherries”, “Sleeping angel IV” saddle, etc. Popular traditions and customs are one of the themes that Eudochia Robu often returns to in her paintings: the undressing of the bride, caloianul (a rainmaking and fertility rite in Romania), the winter holidays, etc. In this sense, we can mention the paintings: “Undressing the Bride”, “Winter landscape with carolers”, “Colind”, “Angel and carolers”, “Traditions”, “Calling the rain”, etc. Even works in the genre of landscape or painting of genre contain popular ornaments taken from the carpet, the popular shirt or traditional architecture: “Butuceni. Ornamental Landscape”, “Windy Day”, “Gate I”, “The Last Supper”, “Angel with Eagle”, “Sleeping Angel IV”, etc. Whatever symbol Eudochia Robu uses, the figurative becomes plastic expression in her paintings.

Mitigating Dry–Hot–Windy Climate Disasters in Wheat Fields Using the Sprinkler Irrigation Method

The dry–hot–windy climate frequently occurs during the grain-filling stage of winter wheat on the North China Plain (NCP) and thus negatively influences wheat yield. Sprinkler irrigation can improve field temperature and humidity and can be used to mitigate dry–hot–windy climate disasters. A two-season field experiment was carried out on the NCP to test how sprinkler irrigation influences the microclimate, canopy temperature and photosynthetic traits, as well as the grain-filling process and final grain yield, when spraying 1.5–2 mm of water on dry–hot–windy days. Field experiments revealed that, compared with the no-spraying treatment, spraying with 2 mm of water each time caused the air and canopy temperatures to decrease by 2.3–7.6 °C and 4.3–9.9 °C, respectively, during and just after spraying stopped, and the temperatures returned to their previous levels approximately one hour after spraying. The air humidity increased by up to 10% during and after spraying. The photosynthesis and transpiration rates and the stomatal conductivity after spraying increased by 34–235%, 15–55% and 24–79%, respectively. The linear relationships between photosynthesis rates and transpiration rates with respect to stomatal conductivity suggest that increases in both photosynthesis and transpiration rates are the main contributors to the increase in stomatal conductivity, which is due mainly to the improved canopy temperature and humidity conditions caused by spraying practices. The grain-filling process was improved by spraying, which ultimately increased the unit grain mass by approximately 5%. One spraying event on a dry–hot–windy day influenced the field microclimate and canopy photosynthetic traits for 90 min (30 min in spraying time + 60 min after spraying). When the intensity of the dry–hot–windy climate is strong, two spraying events can be applied. Spraying 2–2.5 mm of water each time was sufficient when the leaf area index was 4–5 during the grain-filling stage of winter wheat. Spray events can have a slight effect on grain yield when a dry–hot–windy climate occurs within the last five days before harvest.

Design and implementation of an Unmanned Aerial Vehicle (UAV) for image capture in enterprise farming

Unmanned aerial vehicle (UAV), also known as drone is one of the most interesting emerging technologies with a wide range of applications including agriculture, surveillance, security, search and rescue, mapping, farmland surveying, and wildlife conservation, among others. In Nigeria, UAV is gaining popularity in applications such as in social functions for taking both moving and static pictures, military and security, mapping and agriculture. In this work, an UAV was designed, some components produced by 3D printing, coupled and tested with certain level of local content in view. The UAV is a quadcopter equipped with a camera for real-time image capture of farmlands and it can perform autonomous missions by using global positioning system (GPS) waypoints. The weight of the quadcopter was approximately calculated and hence the electrical and mechanical components selected using a standard empirical design table. The thrust to weight ratio was set at 2:1. Autodesk Maya and Inventor software were used to design the frame in two parts: the frame arms on which the propellers are mounted and the central connecting part that links the four arms. The arms are made up of aluminum square pipes while the central connecting part for the arms was printed with a 3D printer (200 x 200 x 200 Wanhao duplicator i3) using PolyEthylene Terephthalate Glycol (PETG) Filament material of 1.75mm standard gauge. Material selection was based on material strength, cost and availability. NCH Debut video and image capture software was used to record live feeds from the UAV onboard camera. Functionality tests for lift, stability, yaw, roll, pitch, loiter, auto landing, return to launch, flight time, altitude/signal, auto mission using GPS waypoints were carried out with the completed UAV on a less windy day to avoid the influence of wind. It was generally observed that the UAV successfully took off the ground, gained stability, flew to over 100m height, captured aerial photographs of the land below it while on flight at the required height and landed safely. Cost saving advantage of 45.28% was achieved when compared to imported equivalent types.

From Windy Day Stories to Wind Farms of the Future: Leveraging Student Resources to Make Sense of Phenomena with Data Puzzles

From Windy Day Stories to Wind Farms of the Future: Leveraging Student Resources to Make Sense of Phenomena with Data Puzzles

The collapse of the Tacoma Narrows bridge-- Why?

In 1940, a new bridge over the Tacoma Narrows south of Seattle went into violent oscillation for over an hour and then collapsed, with the loss of one dog's life. The bridge satisfied all of the engineering standards but the first windy day doomed it. What happened? A variety of explanations have been advanced, but the cause turned out to be quite simple, though unexpected. (It was not resonance.) There are many similarities between it and the fundamental playing behaviour of wind instruments, a positive feedback mechanism coupling the bridge to the wind. (It was not resonance.) In 2006, Daniel Green and I, using a finite element program of G. Morgenthal, showed what triggered this positive feedback mechanism in the case of the bridge, and this talk will discuss the features of our explanation

Empirical Evidence of Reduced Wildfire Ignition Risk in the Presence of Strong Winds

Anyone who has tried lighting a campfire on a windy day can appreciate how difficult it could be. However, despite real-life experience and despite laboratory experiments which have demonstrated that fire ignition risk dramatically decreases beyond a certain wind threshold, current fire weather indices (FWIs) do not take this effect into account and assume a monotonic relation between wind velocity and ignition risk. In this paper, we perform a global analysis which empirically quantifies the probability of ignition as a function of wind velocity. Using both traditional methods (a logistic regression and a generalized additive model) and machine learning techniques, we find that beyond a threshold of approximately 3–4 m/s, the ignition risk substantially decreases. The effect holds when accounting for additional factors such as temperature and relative humidity. We recommend updating FWIs to account for this issue.

Microgrids Imitate Nature for Improved Performance—Use of Nature-Inspired Optimization Techniques in Future Power Systems

There is a constant push towards increasing use of renewable energy-based distributed generators around the globe. While they provide a clean and sustainable source of energy, they employ technologies that are unknown to traditional power systems. These generators are interfaced via inverters that lack the inertia of large synchronous machines. This manifests itself as a more volatile frequency profile that is susceptible to disturbances. This phenomenon is more amplified in stand-alone microgrids which are utilized as a popular electrification alternative in isolated or underserved communities. One solution approach takes its inspiration from nature, e.g., behavior of bees, butterflies, or ants. When employed in a suitable way, animals’ natural behavior helps optimize interaction between different renewable-energy based generators and create a more stable microgrid. There are different approaches to stabilizing such systems with novel optimization approaches. Some of them optimize the ratio between generators that utilize rotating machines and inverters. Penetration of renewable energy generation is about increasing the share of inverter-interfaced generators in the system without causing stability issues. Since renewable energy resources are intermittent and not dispatchable, it is important to create a diverse portfolio where the overall system achieves some stability. For instance, if a local grid is fed by PV panels, wind generation and a small-scale hydroelectric power plant, the varying nature of these resources may complement each other. On a sunny day, PV output might be very high, and wind may not be so significant. On the other hand, on a rainy day, clouds may reduce PV output while precipitation may feed the local hydro power plant. Similarly, wind generation might complement others on a windy day. While the idea is easy to comprehend qualitatively, finding the correct ratio is not trivial. Furthermore, there are many factors at play that are independently changing and impacting the outcome. For different sites, the available renewable energy resources, their profiles as well as the local load conditions would be different. Therefore, a systematic approach is required to optimize these systems at planning, operation and control levels. Nature-inspired optimization algorithms seem to have an edge in doing just that.

Comparing Regional Energy Consumption for Direct Drone and Truck Deliveries

Drone delivery, once thought of as fictitious, is becoming a reality with the efforts of both forward-looking enterprises and supportive government policies. This emerging mode of e-commerce delivery raises many concerns. One important concern is the energy efficiency of direct delivery drones compared with conventional delivery trucks at a regional systems level. In this study, we develop and apply methods to quantify the regional energy impacts of drone delivery, then we assess these impacts and compare them with the impacts of truck delivery. To study this problem, we develop an optimization model that determines an optimal set of fulfillment centers (FCs) with variable service capacities that allow drones to make direct e-commerce deliveries. We adopt two drone delivery energy estimation models from the literature and use them as inputs to demonstrate the potential range of energy needs. We also develop another optimization model to account for the energy consumption of diesel trucks (DTs) and battery electric vehicles (BEVs). We test the models using validated simulation data for the Chicago metropolitan area in the U.S. to quantify the energy implications of these three delivery modes. For drone delivery, we further extend our analyses by considering the impact of wind speed and flight patterns. Our results show that direct delivery drones require 15.8% more energy than BEVs on an average windy day, and they need 15% more energy than DTs on a very windy day. We provide essential parameter values for reproducibility and list relevant open problems.

Utilization of Solar Energy for Water Desalination and Purification Using Solar Concentrator

This paper focuses on a a solar energy-based project aimed at water desalination and purification. The project's objective is to establish an economically viable and sustainable approach to water heating and desalination, offering benefits to global communities. The project team has devised a solar heating system utilizing a Fresnel array-inspired setup, intended to complement a desalination system employing membrane distillation, which necessitates water heating. The primary focus has been on designing an efficient solar receiver to absorb solar energy for water heating. Moreover, the team has developed equations for concentrator mirror angles across various days, generating charts indicating optimal mirror angles and spacing between mirror rows for different solar times. Project outcomes involve applying heat transfer loss theory via conduction across individual receiver layers, conducting experiments to assess coating efficiency and receiver performance. The team successfully assembled the system with four parallel mirror rows, spaced at 1.5 feet intervals to minimize shadow casting. The solar receiver features two glass tubes, air gaps held by 3D-printed end caps, and an internal mesh turbulator to enhance heat transfer through flow turbulence. The ultimate objective was to heat water sufficiently for membrane distillation (around 40°-70°C). Experimental testing on a windy day with clouds resulted in a final water temperature of 38°C after 3 hours. Receiver efficiency, calculated by comparing solar energy incident on the pipe to energy transferred to water, was 17.5%. While not within the desired range, these promising results, considering surrounding conditions, deem the project successful in creating an efficient heating system for membrane distillation. Recommendations and improvements are possible, confirming the project as a successful proof of concept.

On Remembering Hanau and Being an Emotional Academic

On Remembering Hanau and Being an Emotional Academic

Background segmentation in difficult weather conditions.

Background segmentation is a process in which an algorithm removes the static background from an image. This allows only a changing section of the image. This process is important for motion detection or object tracking. In this article, an approach is proposed to compare several existing algorithms for background segmentation under severe weather conditions. Three weather conditions were tested: falling snow, rain and a sunny windy day. The test algorithms were executed on a test video containing frames collected by a dedicated Raspberry Pi camera. The frames used in the tests included cars, bicycles, motorcycles, people, and trees. Preliminary results from these tests show interesting differences in detail detection and detection noise.

EDCB ET AA: A Mnemonic for Resuscitating Hypothermic Patients Under Extreme Conditions

EDCB ET AA: A Mnemonic for Resuscitating Hypothermic Patients Under Extreme Conditions

The Poetry of Punishment

"On a radiant Monday morning in May, I am at the middle school, waiting to see who I have today for In School Suspension. Minivans are pulling up in front, and I open the window and let the breeze blow in the first image of the poem I will spend the day writing. It's a windy day, and everything is in motion, clouds, trees, kids heading into their day at school. Using my fingers to count out syllables, I find the words for my first line, in iambic pentameter. The day's sonnet is underway […]"

Musical Effects in Anne Brontë's Poem “Lines Composed in a Wood on a Windy Day”

Musical Effects in Anne Brontë's Poem “Lines Composed in a Wood on a Windy Day”

Potential of medium-resolution satellite imagery for monitoring sand transport in pre-Saharan urban areas

One of the most spectacular manifestations of desertification is silting up. On a sandy windy day in the Saharan environment, the atmosphere can be so loaded with solid matter that it feels like twilight. It thus presents a danger and a health risk for the population at two levels: i) at the respiratory level, firstly because of the inhalation of solid matter and ii) at the level of sight; solids entering the eye can cause irritation and over time serious infections. One of the most spectacular manifestations of desertification is silting up. On a sandy windy day in the Saharan environment, the atmosphere can be so loaded with solid matter that it feels like twilight. Wind erosion is the main cause of all silting up, the wind playing the double role of erosive agent and transport agent. However, in pre-Saharan environments, sand can also be transported by bedload in wadis; in some cases, the sand can also be of very local origin (erosion of soft sandstone for example); some popular cultures then speak of a "source of sand" which they describe as "inexhaustible". The silting up of a territory can be accelerated (climatic conditions, existence of favorable transport corridors) or slowed down by natural screens (vegetation or relief, for example). Studying the silting up and trying to understand its causes and evolution requires having a multi-date synoptic view of the territory; satellite imagery then appears to be the most appropriate means to provide adequate basic information. The present study has three main objectives: i) delimit areas covered with sand or likely to be; ii) delimit the potential foci (or sources) of supply for the silting up phenomenon and finally iii) hypothesize on the progression of the silting up phenomenon for a pre-Saharan area where we are witnessing a significant and rapid extension to the both urban space and cultures on the outskirts. It mainly concerns the city of Laghouat, a former oasis in the southern foothills of the Saharan Atlas, and its periphery. The population of Laghouat increased from 42,800 inhabitants in 1977 to 119,043 inhabitants in the year 2003 (estimate), i.e. a variation of 178% (i.e. a multiplication by a factor of 2.8) in 26 years resulting in increasingly important consumption needs of all kinds and a profound change in space. It is estimated at 170,693 in 2021. Data from the National Statistics Office are only available until 2019 for overall statistics. For the present work we used several satellite images at different spatial resolutions: a Landsat MSS image from April 1972 at 80 meters resolution, two Landsat TM images at 30 meters from April 1987 and April 2000 and finally an image extract. ASTER from 2004 to 15 meters. We applied a specific index combining some of the channels to accentuate the perception and the distinction of the zones of transfer and accumulation of sand. The comparative analysis of the images makes it possible to specify, firstly, the preferred directions of sand transport and, secondly, the directions of transport and then the areas likely to be most affected.

Studying the Rate of Evaporation Using Pocket and Computer-Supported Weighing Scales

Already when they enter primary school, children have rich everyday experience with factors influencing the rate of liquids’ evaporation. Tea spilled into a large puddle on the table evaporates more rapidly than the same amount remaining in the cup, laundry hanging on a clothesline dries faster on a hot and windy day in comparison with a cold and windless one. We use examples such as these when we tell students that the rate of evaporation is affected by the temperature of a liquid, its surface area, and the airflow above the surface that accelerates the removal of vapors; the type of liquid is also essential. This paper describes a simple way of approximate quantification of these effects in a few hands-on experiments using weighing scales.

Moving People Tracking and False Track Removing with Infrared Thermal Imaging by a Multirotor

Infrared (IR) thermal imaging can detect the warm temperature of the human body regardless of the light conditions, thus small drones equipped with the IR thermal camera can be utilized to recognize human activity for smart surveillance, road safety, and search and rescue missions. However, the unpredictable motion of the drone poses more challenges than a fixed camera. This paper addresses the detection and tracking of people through IR thermal video captured by a multirotor. For object detection, each frame is first registered with a reference frame to compensate for its coordinates. Then, the objects in each frame are segmented through k-means clustering and morphological operations. Falsely detected objects are removed considering the actual size and the shape of the object. The centroid of the segmented area is considered the measured position for target tracking. The track is initialized with two-point differencing initialization, and the target states are continuously estimated by the interacting multiple model (IMM) filter. The nearest neighbor association rule assigns the measurement to the track. Tracks that move slower than the minimum speed are terminated at the proposed criteria. In the experiments, three videos were captured with a long-wave IR band thermal imaging camera mounted on a multirotor. In the first and second videos, eight pedestrians on a pavement and three hikers on a mountain on winter nights were captured, respectively. In the third video, two walking people with complex backgrounds were captured on a windy summer day. The image characteristics vary between videos depending on the climate and surrounding objects, but the proposed scheme shows the robust performance in all cases; the average root mean squared errors in position and velocity are obtained as 0.08 m and 0.53 m/s, respectively for the first video, 0.06 m and 0.58 m/s, respectively for the second video, and 0.18 m and 1.84 m/s, respectively for the third video. The proposed method reduces false tracks from 10 to 1 in the third video.

When the doorbell rings in COVID-19 times: Numerical insights into some possible scenarios.

As ongoing Corona virus disease 2019 pandemic is ravaging the world, more and more people are following social distancing norms, avoiding unnecessary outings and preferring online shopping from the safety of their home over visiting brick and mortar stores and neighborhood shops. Although this has led to a significant reduction in chances of exposure, human-to-human interaction at the doorstep of the customer might be involved during the delivery of the ordered items. This human-to-human doorstep interaction arises in some other situations also. There is a finite probability that the person standing in front of the door coughs or sneezes during such an interaction. In this work, a three dimensional (3D) Euler–Lagrangian computational fluid dynamic model is used to understand the transmission and evaporation of micrometer-size droplets generated due to a coughing event in this setting. Different possible scenarios varying in wind direction, wind velocity, ventilation in the vicinity of door, and extent of door opening have been postulated and simulated. The results obtained from numerical simulations show that in the presence of wind, the dynamics of transmission of droplets is much faster than the dynamics of their evaporation. Thus wind velocity and direction have a significant impact on the fate of the droplets. The simulation results show that even if the door is opened by a very small degree, cough droplets enter through the door. Having open windows in the vicinity of the door on a windy day is expected to reduce the chance of the exposure significantly.

Video monitoring of in‐channel wood: From flux characterization and prediction to recommendations to equip stations

AbstractWood flux (piece number per time interval) is a key parameter for understanding wood budgeting, determining the controlling factors, and managing flood risk in a river basin. Quantitative wood flux data is critically needed to improve the understanding of wood dynamics and estimate wood discharge in rivers. In this study, the streamside videography technique was applied to detect wood passage and measure instantaneous rates of wood transport. The goal was to better understand how wood flux responds to flood and wind events and then predict wood flux. In total, one exceptional wind and seven flood events were monitored on the Ain River, France, and around 24,000 wood pieces were detected visually. It is confirmed that, in general, there is a threshold of wood motion in the river equal to 60% of bankfull discharge. However, in a flood following a windy day, no obvious threshold for wood motion was observed, which confirms that wind is important for the preparation of wood for transport between floods. In two multi‐peak floods, around two‐thirds of the total amount of wood was delivered on the first peak, which confirms the importance of the time between floods for predicting wood fluxes. Moreover, we found an empirical relation between wood frequency and wood discharge, which is used to estimate the total wood amount produced by each of the floods. The data set is then used to develop a random forest regression model to predict wood frequency as a function of three input variables that are derived from the flow hydrograph. The model calculates the total wood volume either during day or night based on the video monitoring technique for the first time, which expands its utility for wood budgeting in a watershed. A one‐to‐one link is then established between the fraction of detected pieces of wood and the dimensionless parameter “passing time × frame rate”, which provides a general guideline for the design of monitoring stations.

"Potential of medium-resolution satellite imagery for monitoring sand transport in pre-Saharan urban areas"

One of the most spectacular manifestations of desertification is silting up. On a sandy windy day in the Saharan environment, the atmosphere can be so loaded with solid matter that it feels like twilight. It thus presents a danger and a health risk for the population at two levels: i) at the respiratory level, firstly because of the inhalation of solid matter and ii) at the level of sight; solids entering the eye can cause irritation and over time serious infections. One of the most spectacular manifestations of desertification is silting up. On a sandy windy day in the Saharan environment, the atmosphere can be so loaded with solid matter that it feels like twilight. Wind erosion is the main cause of all silting up, the wind playing the double role of erosive agent and transport agent. However, in pre-Saharan environments, sand can also be transported by bedload in wadis; in some cases, the sand can also be of very local origin (erosion of soft sandstone for example); some popular cultures then speak of a "source of sand" which they describe as "inexhaustible". The silting up of a territory can be accelerated (climatic conditions, existence of favorable transport corridors) or slowed down by natural screens (vegetation or relief, for example). Studying the silting up and trying to understand its causes and evolution requires having a multi-date synoptic view of the territory; satellite imagery then appears to be the most appropriate means to provide adequate basic information.