Wind Chill Research Articles

Hypothermia Progression Time Course for Evacuation Planning

Introduction:Accidental hypothermia occurs very rarely. Japan experienced hypothermic victims in the 2011 earthquake and tsunami disaster. In northern Japan, where the largest class of earthquakes and tsunamis are estimated, study for countermeasures has been advanced. The progression of hypothermia varies significantly by individual differences and environmental factors, and it is considered to be challenging to assess its damage. We present the findings that can be the basis for damage estimation from the data of hypothermia victims experienced in mountain rescue.Method:From 2002 to 2020, we examined ten fatal cases of hypothermic witnessed respiratory arrest (HWRA) by companions, which led to subsequent cardiac arrest among 164 cases from mountain rescue. We collected the time course of the deceased from rescue records and calculated the time from cold exposure to symptom, exposure to incapable, and exposure to HWRA. Temperature and wind speed data were extrapolated from nearby AMEDAS and upper-air weather records, and the wind chill index (WCI) was calculated.Results:We obtained the time course data in seven cases of ten, five males and two females between 21 and 67 years old. The weather conditions where the seven cases were placed were -5 to -30°C of WCI. The shortest time from cold exposure to incapacity was 65 minutes, 42.9% (3/7) within 180 minutes, and the fastest time to HWRA was 90 minutes, with 57.1% (4/7) between 10 and 12 and half hours.Conclusion:For disaster evacuation measures, both evacuees and rescuers need specific indicators to refer to. From very little but valuable data, we consider that rescue within 10 hours is necessary for lifesaving in similar conditions. Additionally, increasing the number of cases that become incapacitated within 1-3 hours can be valuable information for considering the location of the evacuation shelter and evacuation plan.

Analysis of Back EMF Harmonics Influenced by Slot–Pole Combinations in Permanent Magnet Vernier In-Wheel Motors

This paper analyzes the back-EMF harmonic characteristics influenced by the slot-pole combinations in permanent magnet vernier motors (PMVM) for in-wheel drive applications. Firstly, the feasible matches between the slot-pole combinations, stator tooth types, as well as winding topologies are given. Secondly, the expressions of fundamental and harmonic back-EMF are then derived, where the equivalent winding factor considering the air-gap permeance harmonics is introduced to evaluate the back-EMF fundamental amplitude. Next, the contribution of each air-gap magnetic field harmonic on the back-EMF harmonic is investigated, which has proven that the air-gap odd-order ineffective magnetic field harmonics are responsible for unexpected back-EMF harmonics. Based on this, the feasible principle of the number of PM poles, armature poles, and flux modulation poles aiming at the low ineffective back-EMF harmonics is established. Finally, extensive finite element analysis (FEA) is conducted, and two prototypes were manufactured and tested, where the experimental results have a good agreement with the FEA and theoretical results.

Statistical Study of the Ionospheric Slab Thickness at Beijing Midlatitude Station

The ratio of the total electron content (TEC) to the F2-layer peak electron density (NmF2) is known as the ionospheric equivalent slab thickness (EST, also known as τ), and it is a crucial indicator of the ionosphere. Using TEC and NmF2 data from the years 2010 to 2017, this work conducts a comprehensive statistical analysis of the ionospheric slab thickness in Beijing, which is in the midlatitude of East Asia. The outcomes show that the τ have different diurnal variations at different seasons for high/low-solar-activity years. On the whole, daytime τ significantly greater than nighttime τ in summer, and it is the opposite for the τ in winter regardless of the solar cycle, whereas the τ during equinox shows different morphology for high/low-solar-activity years. Specifically, daytime τ is larger than nighttime τ during equinox in years of high-solar activity, while the opposite situation applies for the τ during equinox in years of low-solar activity. Moreover, the pre-sunrise and post-sunset peaks are most pronounced during winter for low-solar-activity years. In summer, there is a great increase in τ during the morning hours when compared with other seasons. Furthermore, the τ decreases with the solar activity during nighttime, whereas it seems there is no correlation between daytime τ and solar activity. This paper explained the primary diurnal variations in τ across different seasons during high-/low-solar-activity years by analyzing relative fluctuations of TEC and NmF2 throughout the corresponding period. In addition, based on the disturbance index (DI), which is calculated by instantaneous τ and its corresponding median, this paper found that the storm-time τ might increase when compared with its median value during the daytime, while it may both increase and decrease during the nighttime, especially around dawn and dusk hours. To further analyze the physical mechanism, an example on 2 October 2013 is also presented. The results indicate that the positive disturbance of τ during the main phase of a geomagnetic storm might be caused by the prompt penetration electric field and neutral wind during the storm, and the τ increases during the early recovery phase might be due to the disturbance dynamo electric field as well as the neutral wind during the storm. Moreover, there is a negative disturbance of τ in the recovery phase during the most disturbed sunrise hours, and it might be due to the electric field reversal, neutral wind or other factors during this period. This paper notes the differences of τ in midlatitude between different longitudinal sectors from the related climatology and storm-time behavior, as it would be helpful to improve the current understanding of τ at midlatitudes in East Asia.

A preliminary study of the thermal strain experienced by dive support boat personnel

ABSTRACT Anecdotal evidence indicated some British military dive support boat personnel suffer from uncomfortably cold hands and feet, which could impair their performance and be associated with reductions in core body temperature. This study collected preliminary data on thermal stress and cognitive performance of personnel taking part in a cold-weather training exercise. Six men were monitored during four boat transits in a range of climatic conditions (air temperature +1.2°C to −10.5°C, wind chill −4.5°C to 19.3°C). Core body temperature was measured with a radio pill and 12 skin sites (ISO 9886 plus hand, finger, foot and toe) with iButtons or thermistors. Self-reported thermal comfort and thermal sensation was also recorded. Reaction time and selective attention were measured pre- and post-transit. Participants’ physical characteristics and personal clothing ensembles were recorded. No participant became hypothermic. Most participants’ hand, foot and digit temperatures fell to below 15°C, indicating a risk of impaired dexterity, in addition to that arising from gloves. During the trial, hand and digit temperatures occasionally fell below 10°C. The limited data collected showed personal clothing choices could provide adequate thermal protection for these conditions and temperatures, and highlighted inter-individual variation and the need to allow for significant variation of day-to-day environmental conditions.

Study of Winding Structure to Reduce Harmonic Currents in Dual Three-Phase Motor

Dual three-phase motors have the problem of a large generation of harmonic currents while driving due to small inductance for certain harmonics. The purpose of this paper is to theoretically clarify the effect of the winding structure of dual three-phase motors on harmonic currents. Analytical calculations considering the spatial harmonics of the magnetomotive force are used to formulate the inductance that depends on the winding structure and the harmonic order. The validity of the formulated theoretical expression of the inductance is confirmed by finite element analysis. In addition, drive simulations of the coil pitch 5/6 dual 3-phase motor and the coil pitch 1 dual 3-phase motor are performed, and it is found that the magnitude of the generated harmonic currents can be explained using the formulated inductance values. In conclusion, it is found that dual three-phase motors with large winding factors for fifth and seventh order spatial harmonics can reduce the harmonic currents.

Research on MASS Collision Avoidance in Complex Waters Based on Deep Reinforcement Learning

The research on decision-making models of ship collision avoidance is confronted with numerous challenges. These challenges encompass inadequate consideration of complex factors, including but not limited to open water scenarios, the absence of static obstacle considerations, and insufficient attention given to avoiding collisions between manned ships and MASSs. A decision model for MASS collision avoidance is proposed to overcome these limitations by integrating the strengths of model-based and model-free methods in reinforcement learning. This model incorporates S-57 chart information, AIS data, and the Dyna framework to improve effectiveness. (1) When the MASS’s navigation task is known, a static navigation environment is built based on S-57 chart information, and the Voronoi diagram and improved A* algorithm are used to obtain the energy-saving optimal static path as the planned sea route. (2) Given the small main dimensions of an MASS, which is easily affected by wind and current factors, the motion model of an MASS is established based on the MMG model considering wind and current factors. At the same time, AIS data are used to extract the target ship (manned ship) data. (3) According to the characteristics of the actual navigation of ships at sea, the state space, action space, and reward function of the reinforcement learning algorithm are designed. The MASS collision avoidance decision model based on the Dyna-DQN model is established. Based on the DQN algorithm, the agent (MASS) and the environment interact continuously, and the actual interaction data generated are used for the iterative update of the collision avoidance strategy and the training of the environment model. Then, the environment model is used to generate a series of simulated empirical data to promote the iterative update of the strategy. Using the waters near the South China Sea as the research object for simulation verification, the navigation tasks are divided into three categories: only considering static obstacles, following the planned sea route considering static obstacles, and following the planned sea route considering both static and dynamic obstacles. The results show that through repeated simulation experiments, an MASS can complete the navigation task without colliding with static and dynamic obstacles. Therefore, the proposed method can be used in the intelligent collision avoidance module of MASSs and is an effective MASS collision avoidance method.

Data driven machine learning models for short‐term load forecasting considering electrical vehicle load

AbstractElectric vehicles (EVs) are gaining popularity due to their fuel efficiency and ability to reduce greenhouse gas emissions. Significant penetration of EVs with unregulated charging, which can have a substantial impact on power networks. Accurate load predictions, including the charging of EVs are crucial for ensuring the cost‐effective and dependable operation of power systems. In order to estimate short‐term load in the presence of EV load, the XG (extreme gradient) boost algorithm is proposed and the effectiveness of the performances are checked against other models. A variety of distinct meteorological parameters and the electrical load pattern for the years 2017 and 2018 for Northeast India are used to train the machine learning classifier models. R‐squared value analyses are also performed to identify the most correlated input parameters that influence the results of various models. Analysis shows that temperature, cloud cover, heat index, dew point, wind chill, and perceived temperature are substantially connected with electricity consumption. The performance of XG boost is outperformed by comparing prediction results with decision tree, random forest, K nearest neighbors, and logistic regression. Three separate case studies were employed for verification using the precision, F1 score, sensitivity, specificity, and accuracy metrics. Our findings demonstrate that, in comparison to other forecasting models, XG Boost exhibits higher accuracy (83.84%, 81.51%, and 85.97%) and robust forecasts.

LASSO and attention-TCN: a concurrent method for indoor particulate matter prediction.

Long time exposure to indoor air pollution environments can increase the risk of cardiovascular and respiratory system damage. Most previous studies focus on outdoor air quality, while few studies on indoor air quality. Current neural network-based methods for indoor air quality prediction ignore the optimization of input variables, process input features serially, and still suffer from loss of information during model training, which may lead to the problems of memory-intensive, time-consuming and low-precision. We present a novel concurrent indoor PM prediction model based on the fusion model of Least Absolute Shrinkage and Selection Operator (LASSO) and an Attention Temporal Convolutional Network (ATCN), together called LATCN. First, a LASSO regression algorithm is used to select features from PM1, PM2.5, PM10 and PM (>10) datasets and environmental factors to optimize the inputs for indoor PM prediction model. Then an Attention Mechanism (AM) is applied to reduce the redundant temporal information to extract key features in inputs. Finally, a TCN is used to forecast indoor particulate concentration in parallel with inputting the extracted features, and it reduces information loss by residual connections. The results show that the main environmental factors affecting indoor PM concentration are the indoor heat index, indoor wind chill, wet bulb temperature and relative humidity. Comparing with Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU) approaches, LATCN systematically reduced the prediction error rate (19.7% ~ 28.1% for the NAE, and 16.4% ~ 21.5% for the RMSE) and improved the model running speed (30.4% ~ 81.2%) over these classical sequence prediction models. Our study can inform the active prevention of indoor air pollution, and provides a theoretical basis for indoor environmental standards, while laying the foundations for developing novel air pollution prevention equipment in the future.

Are Drought and Wind Force Driving Factors of Wind Erosion Climatic Erosivity in a Changing Climate? A Case Study in a Landlocked Country in Central Europe

The intensity and frequency of occurrence of wind erosion have had an increasing tendency in recent years, exacerbating environmental and agricultural problems around the world. The question of whether climate change will have an accelerating impact on wind erosion might be answered by analyzing three driving parameters: wind erosion climatic erosivity (CE), standard precipitation index (SPI), and wind factor (Wf). A time series analysis of historical climatic data over a period of 58 years was performed using ArcGIS software and descriptive statistics, to detect spatiotemporal variations regarding climate change. The results of the analysis indicate that the number and intensity of drought periods are already increasing in Central Europe. Through the CE equation using the key indicators wind speed (U), temperature (T), humidity (r), and precipitation (P), we calculated decadal spatiotemporal variation and potential scenarios of climate change in terms of wind erosion intensity. The results of the study show that there has been a 1.75 °C increase in temperature since 1961 and fluctuating wind erosion intensity in recent decades. The frequency of drought periods has increased only slightly, but there has been an increase in the amount of precipitation in the last two decades of the study period, up to +6.63 and +6.53%. The wind analysis showed that mean maximum wind speed (Umaxmean) had a decreasing trend (R2 = 0.32), and the occurrence of erosive wind (Uer) (>5 m/s) exhibited seasonal changes toward spring. Wf exhibited a rise of 11.86 and 3.66% in the first two decades of the study period, followed by a decline of 8.49% in the last decade. CE analysis indicated oscillation in both directions, with decadal changes ranging between −16.95 and +15.21%. Wind erosion is becoming a more significant issue in Central Europe because of climate change, and the situation could worsen in the future. This study provides valuable insights into the impact of climate change on wind erosion in Europe and highlights the need for effective measures to mitigate its effects.

Analysis of Exchange Power in the Power System of an Unmanned Aerial Vehicle with a BlDC Engine

The purpose of this work is the analysis of the power supply system of unmanned aerial vehicle. One of the most important tasks of this system is to ensure the smallest possible losses in order to achieve greater endurance of the aircraft, which means – the ability to complete the mission. The presence of an inactive component of consumed power obviously reduces the efficiency of the entire unmanned aerial vehicle. Considering also that due to the influence of wind, speed changes and other factors, the power system spends a significant amount of time in the transition mode, the impact of this phenomenon becomes even more significant. Thus, the phenomenon of the occurrence of exchange power in the power supply system of an unmanned aerial vehicle is analyzed. One of the most common solutions for unmanned aerial vehicles is the use of a BLDC motor, which is a further development of DC motors and was created with the aim of improving their basic characteristics. This type of engine has gained its popularity due to numerous advantages: high reliability, efficiency, speed and others. The principles of control of the BLDС engine are given. The unmanned aerial vehicle power supply system, built on the basis of a buck converter and a bridge inverter, was analyzed. An equivalent circuit of the converter is built, taking into account the losses in the electric circuit. On its basis the relations for determining the value of exchange power in the power supply system are derived. With the help of these expressions, it is possible to determine the value of the exchange energy at an arbitrary time interval in the real power supply system of the aircraft. A model of the power supply system of an unmanned aerial vehicle with a BLDC engine was built in the Matlab Simulink software environment. A time diagram is obtained, on the basis of which it is possible to draw a conclusion about the content of exchange power in the converter circuit. To minimize this phenomenon, it is necessary to develop a compensation system or an intelligent control system.

Insights from the first winter weather observations near Mount Everest's summit

Insights from the first winter weather observations near Mount Everest's summit

Development of interactive guidance for cold exposure using a thermoregulatory model

ABSTRACT For decades, the Wind Chill Temperature Index (WCT) and its various iterations have been used to assess the risk of frostbite on unclothed body parts. This paper presents an innovative knowledge-based Cold Weather Ensemble Decision Aid (CoWEDA) that can be used to guide the selection of the most appropriate cold weather ensemble(s) relative to anticipated mission physical activities and environmental conditions. CoWEDA consists of a validated six-cylinder thermoregulatory model, a database of clothing properties, algorithms for calculating the whole ensemble properties from individual garments and a graphical user interface. The user-friendly CoWEDA allows users to select from an inventory of clothing items to build an ensemble suitable for their needs. CoWEDA predicts the risks of both frostbite and hypothermia and ensures that a selected clothing ensemble will provide adequate protection to prevent cold injury. CoWEDA predictions provide not only estimates of frostbite risk similar to WCT tables but also hypothermia times and clothing required to prevent cold injuries. In addition, a CoWEDA model variant can predict survivability and clothing requirements during cold water immersion. Thus, CoWEDA represents a significant enhancement of the WCT-based guidance for cold weather safety and survival by providing greater individual fidelity in cold injury predictions.

Changes in complex bioclimatic indicators in Crimea since the middle of the 20th century

BACKGROUND: Observed global climate changes can significantly influence on the regional climate anomalies and recreational conditions over the Crimean peninsula.
 AIM: To study the features of complex bioclimatic indicators changes on the territory of Crimea over a multidecadal period (~70 years), paying special attention to each month of the year, and on bases of obtained results to show the possible way of recreational activities development associated with these changes.
 METHODS: For calculations, we used daily hydrometeorological data for each month from the archive of observations at the network of European weather stations E-OBS (v. 17.0) from 22 stations and NCEP/NCAR R1 reanalysis for the period of 19502018. The obtained arrays were verified in accordance with an open database of standard daily station observations in Crimea in 20052018. To assess the impact of climate change on the human body, the equivalent effective temperature, normal equivalent effective temperature, weight content of oxygen in the air (partial oxygen density) (O2), wet wind chill index Hill (Hw) and index Bodmann dry wind chiller (S) were calculated. The features of their linear trends for each month in the Crimean Peninsula were analysed.
 RESULTS: Monthwise analyses of the bioclimatic indicator trends demonstrated an increase or decrease in recreational comfort in certain seasons. The most pronounced positive normal equivalent effective temperature trends over Crimea were observed from winter to spring. This indicated improved complex recreational conditions in recent decades and the possibility to extend the duration of the holiday season. The pO2, Hw and S indices had opposite tendencies throughout the year (except for December). According to the pO2 index, in the period from August to October, a physiological oxygen deficiency may be experienced throughout Crimea. Windy and uncomfortable bioclimatic conditions tend to increase in the steppes of Crimea in December.
 CONCLUSION: The patterns of changes in bioclimatic indicators revealed through this study can be used as a regulatory factor for effectively organising and conducting recreational activities in the territory of Crimea and thus ensure the duration of the recreational period.

Influence of filament number and size on the basic properties of in situ made MgB2 wires

Monel-sheathed MgB2 wires with 6, 18 and 54 filaments of diameter 0.83 mm manufactured by Sam Dong Co., Ltd, have been subjected to twisting, drawing and rolling and measurements at low temperatures. R(T), I–V characteristics, critical currents and stress/strain tolerances of these wires were analyzed. Low reduction of critical current (⩽10%) by twisting between 50 mm and 12.5 mm was observed, especially for the wire with 54 filaments, which also showed the best strain tolerance to tension, ∼0.43% at 4.2 K. The engineering current density of the 18-filament wire was decreased by 56% by drawing from 0.83 mm to 0.4 mm, but improved by ∼24% by rolling from 0.83 mm to 0.64 mm. A small uninsulated coil was made from wire flattened from 0.83 mm to 0.64 mm by the wind and react process, resulting in a very high winding packing factor of 0.91 and also a high winding current density of 104 A cm−2 at B ⩽ 5.6 T. The presented properties are interesting for possible applications of these MgB2 wires in DC windings.

A Case for Micromachines in Laboratory-Based DFIG Wind Turbine Systems for Fault Studies

For laboratory-based systems, the selection of components is critical to ensure proper representation of the actual system. In past investigations, researchers made use of small-scale off-the-shelf wound rotor induction machines (WRIMs) to perform laboratory-based studies. However, there are no reports validating their applicability in comparison to using the actual machines. In this regard, this paper investigates the correlation between the dimensional parameters and the electrical asymmetry indicators for a large-scale wind generator and laboratory-based generators. For the latter, a comparison is made between using a standard small-scale off-the-shelf WRIM and a micromachine. It is shown that the harmonic frequencies in a healthy machine and those due to inherent asymmetries appear at the same positions on the stator current spectrum for the three machines. However, there is a difference in the amplitudes of these components, given their dependence on the winding factors for a specific machine. The dimensional analysis techniques used to scale down the large-scale generator into a micromachine ensure that these parameters are related. However, this is not the case for the standard small-scale WRIM. Further work demonstrates the correlation of the fault-related harmonics between the micromachine and the large-scale machine for a rotor inter-turn fault condition. Micromachines are designed to ensure that the time constants are proportional representations of the larger machine, thus providing an accurate reflection of what is expected under transient operating conditions of wind turbines. This would assist in the development of condition monitoring strategies that are suited for the actual systems in the industry.

Effects of Eulerian current, Stokes drift and wind while simulating surface drifter trajectories in the Baltic Sea

The simulation of Lagrangian drift is an important task in applications such as dispersion of pollutants, larvae and search and rescue activities. In this study, the Eulerian current, Stokes drift and wind effect on the simulation of observed drifters were analysed. The Lagrangian OceanParcels model was used, and the surface trajectories were assessed by comparison with 9 GPS drifter trajectories in the Gulf of Finland, Gulf of Riga and Lithuanian coast. The Normalised Cumulative Lagrangian Separation (NCLS) distance between the simulated and the satellite-tracked drifter trajectories, and the mean absolute error (MAE) were used as comparison metrics. The present study suggests the need to consider the Stokes drift and the wind factor in addition to the modelled Eulerian currents to obtain a better description of the trajectories of particles. By making these considerations, the OceanParcels model could adequately simulate particle trajectories in the sub-basins within the Baltic Sea. The realized model tests showed that motion of surface drifters are strongly controlled by the Stokes drift when the significant wave height is >1 m, whereas the wind component and the Eulerian currents are crucial when the significant wave height is <0.6 m or the wave (Stokes drift) directions do not match the wind direction.

Understanding and improving temporary road sign stability

Temporary road signage is used throughout road networks to regulate traffic and provide warnings to road users. Wind and other factors induce frequent falling of temporary road signage and are a major road safety concern that needs to be addressed. The main aim of this paper was to gain an understanding of temporary road sign stability in the presence of passing road trains and investigate the possibility of stabilising temporary road signage through appropriate design modifications. Simulations and experimental trials were carried out to assess the stability of current temporary road signs used in the industry. This analysis used Ansys Fluent to simulate fluid dynamics in order to infer road sign stability. A field experimental trial was performed in Western Australia’s Pilbara Region using a modified temporary road sign developed based on the outcome of the Ansys simulation. The findings from the simulations showed that the current design is unstable and highly prone to wind induced failure. The simulations suggest that road train transit at 100 km/h is capable of inducing approximately 8 m/s wind velocity in the proximity of the sign, which is greater than that permissible for a rigid sign with no leg mobility. Field trials showed that the modified sign remained stable at 1.2 m from the edge line although it was still prone to falling over at closer distances.

Resource assessment for green hydrogen production in Kazakhstan

Kazakhstan has long been regarded as a major exporter of fossil fuel energy. As the global energy sector is undergoing an unprecedented transition to low-carbon solutions, new emerging energy technologies, such as hydrogen production, require more different resource bases than present energy technologies. Kazakhstan needs to consider whether it has enough resources to stay competitive in energy markets undergoing an energy transition. Green hydrogen can be made from water electrolysis powered by low-carbon electricity sources such as wind turbines and solar panels. We provided the first resource assessment for green hydrogen production in Kazakhstan by focusing on three essential resources: water, renewable electricity, and critical raw materials. Our estimations showed that with the current plan of Kazakhstan to keep its water budget constant in the future, producing 2–10 Mt green hydrogen would require reducing the water use of industry in Kazakhstan by 0.6–3% or 0.036–0.18 km3/year. This could be implemented by increasing the share of renewables in electricity generation and phasing out some of the water- and carbon-intensive industries. Renewable electricity potential in South and West Kazakhstan is sufficient to run electrolyzers up to 5700 and 1600 h/year for wind turbines and solar panels, respectively. In our base case scenario, 5 Mt green hydrogen production would require 50 GW solar and 67 GW wind capacity, considering Kazakhstan's wind and solar capacity factors. This could convert into 28,652 tons of nickel, 15,832 tons of titanium, and many other critical raw materials. Although our estimations for critical raw materials were based on limited geological data, Kazakhstan has access to the most critical raw materials to support original equipment manufacturers of low-carbon technologies in Kazakhstan and other countries. As new geologic exploration kicks off in Kazakhstan, it is expected that more deposits of critical raw materials will be discovered to respond to their potential future needs for green hydrogen production.

The Effect of Wind Chill in Closed House on Broiler Performance

Fan settings (wind speed) in the cage must be adjusted to the age and weight of the chickens. Any movement of the wind at a certain speed will have an impact on the difference between the actual temperature read on the thermometer and the effective temperature felt by the chickens. This is because there is a cold temperature effect (wind chill effect) due to air movement. On the 1st floor of the KTM cage, there was an error setting the fan on which caused the wind speed to be higher than necessary, causing a wind chill effect. This case caused the performance of the chickens in the 1st-floor cage not to reach the target. To get the ideal temperature and wind speed in the cage, the effort needed is to adjust the fan to turn on taking into account the wind chill effect. Based on the results of considering the wind chill effect in the cage, the value of feed intake, body weight gain, and body weight at the age of 7-35 days appear to be higher with a low feed conversion value and a higher production index.

Study on the Basic Performance Deterioration Law and the Application of Lead Rubber Bearings under the Alternation of Aging and Seawater Erosion

Lead rubber isolation bearings are well-recognized as a common and effective means to mitigate the seismic responses of bridges. However, rubber isolation bearings used in offshore bridges are extremely vulnerable to the action of the alternation of aging and seawater erosion caused by weather conditions, wind, waves, and other factors. Meanwhile, the deterioration law and application of lead rubber bearings subject to the effect of aging and seawater erosion cycles are not clear. Thus, aging and seawater erosion cycles testing on both lead rubber isolation bearings (LRB) and rubber materials were carried out. The parameters for the Mooney–Rivlin model of the rubber material used in LRBs were determined and the time-varying law of basic performance of LRBs was obtained based on test results of LRBs and their rubber material. Then, the determined rubber material parameters were applied into the finite-element model of LRBs to verify the basic performance degradation law of the LRBs. Finally, the obtained basic performance degradation law of LRBs was substituted into the finite model of offshore bridges to investigate the impact of the property degradation of LRBs on their seismic performance. The time-varying law of seismic performance of offshore bridge structures was also studied based on finite element analysis. The results show that both the horizontal and vertical stiffness of LRBs increase with the alternating of aging and seawater erosion time, and the horizontal and vertical stiffness increase by 16.1% and 24.3%, respectively, during the 120-year service period. Additionally, the Mooney–Rivlin model parameters of the LRB rubber material are also significantly affected by the alternating of aging and seawater erosion. Additionally, the results also indicate the deterioration of LRBs has a great influence on the anti-seismic performance of offshore bridge structures. After 120 years of service of offshore bridge isolation bearings under the alternating of aging and seawater erosion, the maximum displacement of the pier top of the offshore bridges, the maximum bending moment at the pier bottom, and the maximum displacement of the rubber bearing increased by 14.2%, 6.6%, and 9.1%, respectively. The findings of this paper play an important role in the seismic behavior study and the life-cycle performance analysis of offshore traffic projects such as sea-crossing bridges in marine environments. At the same time, they also lay a theoretical foundation for the performance analysis of rubber isolation bearings and offshore bridge structures under the alternation of aging and seawater erosion cycles.