Compound hot temperature and high chlorophyll extreme events in global lakes

An emerging concern for lake ecosystems is the occurrence of compound extreme events i.e., situations where multiple within-lake extremes occur simultaneously. Of particular concern are the co-occurrence of lake heatwaves (anomalously warm temperatures) and high chlorophyll-a extremes, two important variables that influence the functioning of aquatic ecosystems. Here, using satellite observations, we provide the first assessment of univariate and compound extreme events in lakes worldwide. Our analysis suggests that the intensity of lake heatwaves and high chlorophyll-a extremes differ across lakes and are influenced primarily by the annual range in surface water temperature and chlorophyll-a concentrations. The intensity of lake heatwaves is even greater in smaller lakes and in those that are shallow and experience cooler average temperatures. Our analysis also suggests that, in most of the studied lakes, compound extremes occur more often than would be assumed from the product of their independent probabilities. We anticipate compound extreme events to have more severe impacts on lake ecosystems than those previously reported due to the occurrence of univariate extremes.

Theoretical Analysis of Vuilleumier’s Hypothetical Engine and Cooler

Vuilleumier machines are a promising technology for heating. Respective performances of Vuilleumier’s engine and cooler are generally unclear. In Stirling machines, performances can be determined based on PV power flow and heat flow methods. In this work, respective performances based on two methods in current Vuilleumier models were investigated. It was found that PV power flow and heat flow methods in current Vuilleumier models were ineffective for analysis of respective performances due to there being no piston as a boundary between Vuilleumier’s engine and cooler. Then, a virtual piston was assumed, and a virtual piston based Vuilleumier model (VPBVM) was developed. The relative Carnot efficiencies of the obtained engine and cooler were 53~64% and 43~49%, respectively, at conditions of 550 °C hot temperature, 50~70 °C warm temperature, and −20~10 °C cold temperature. The results indicated that respective performances obtained in VPBVM were reasonable. Moreover, the engine’s compression ratios could be obtained in VPBVM and were 1.2~1.24. Thus, VPBVM could be effective for the analysis of the Vuilleumier machine’s engine and cooler.

Short-Term Impact of Ambient Temperature on the Incidence of Influenza in Wuhan, China

Few studies have estimated the nonlinear association of ambient temperature with the risk of influenza. We therefore applied a time-series analysis to explore the short-term effect of ambient temperature on the incidence of influenza in Wuhan, China. Daily influenza cases were collected from Hubei Provincial Center for Disease Control and Prevention (Hubei CDC) from January 1st, 2014 to December 31st, 2017. The meteorological and daily pollutant data was obtained from the Hubei Meteorological Service Center and National Air Quality Monitoring Stations, respectively. We used a generalized additive model (GAM) coupled with the distributed lag nonlinear model (DLNM) to explore the exposure-lag-response relationship between the short-term risk of influenza and daily average ambient temperature. Analyses were also performed to assess the extreme cold and hot temperature effects. We observed that the ambient temperature was statistically significant, and the exposure-response curve is approximately S-shaped, with a peak observed at 23.57℃. The single-day lag curve showed that extreme hot and cold temperatures were both significantly associated with influenza. The extreme hot temperature has an acute effect on influenza, with the most significant effect observed at lag 0-1. The extreme cold temperature has a relatively smaller effect but lasts longer, with the effect exerted continuously during a lag of 2-4 days. Our study found significant nonlinear and delayed associations between ambient temperature and the incidence of influenza. Our finding contributes to the establishment of an early warning system for airborne infectious diseases.

TAMBAL BAN SEPEDA MOTOR YANG ERGONOMIS MENGGUNAKAN ARDUINO UNO

Tire patch is an activity to repair the tire incompletely only on the part that is leaking. the tire patch tool uses canned gas as a heater, the use of canned gas as a tire heater turns out to have many shortcomings such as the results of the patch being less sticky, the patching time is quite long and it costs a lot of money to buy canned gas. The methodology used in this study is the method of validity, namely testing the hot temperature on an Arduino Uno-based automatic tire patch with a Bluetooth connection. The result of designing an ergonomic motorcycle tire patch tool based on Arduino Uno. The control system tool can work in accordance with its supporting instruments by detecting hot temperatures to operating the device using a Bluetooth connection, there are two types of support systems which are often referred to as software and hardware, so the design process is carried out on both of these supports. The test was carried out 3 times. The first test using a temperature of 80-100 oC takes 3 minutes 28 seconds. The second test using a temperature of 100-120 oC takes 4 minutes 30 seconds with poor results because the results of the patch cannot withstand a large load and cannot withstand being used for too long, while the last or third test uses a temperature of 120-160 oC with the required time. 5 minutes 40 seconds with good patching results.

Design of Cooling and Heating Tool Using Thermoelectric Peltier Based On Arduino Uno

Cooler is an electronic device used to cool food and drinks. The current cooling system still uses refrigerants that can damage the ozone layer. The thermoelectric based cooling system can be used as an alternative since it produces sufficient temperature difference on both sides by considering its advantages that is more environmentally friendly. This research is aimed to design and built a cooling and heating system using a thermoelectric Peltier TEC 12715 based on microcontroller Arduino uno. This system uses the Peltier thermoelectric effects as coolant and warmer because it produces temperature difference on both sides. Based on this research, in the no load condition the system can produce a cold temperature of 21,3 ℃ and a hot temperature of 80,2 ℃ in the 40th minute of use. When given a load of 300 ml and 220 ml drink bottles, the system can produce a cold temperature of 22,2 ℃ and a hot temperature of 70,7 ℃ in the 40th minute of use. The TEC 12715 Peltier component used in this research produces the optimal temperature if a voltage of 12 volts and a current of 15 amperes are applied to each Peltier component. The designed system is able to operate repeatedly, properly, and continuously since it is directly connected to alternative current power which is common in households.

Evolution of extreme hot temperatures over Euro-Mediterranean main airports

<p><span><span>As a result of global warming, the magnitude and the frequency of extreme hot temperature events have increased remarkably in the recent decades. </span><span>In the absence of policies, global warming is expected to continue during the next years, and certain regions which are already characterized by warm and hot temperatures, such as the Euro-Mediterranean region, may be notably impacted in numerous and diverse fields. The aeronautical sector is among these vulnerable fields, as aircraft takeoff performances also depend on air temperature. For instance, a</span><span>n increase in ground temperature results in a decrease in air density, and consequently in the available thrust for takeoff. This may lead to flight delays, weight restrictions or even flight cancellations. Concerning the aircraft engines, an increase in temperature may negatively impact the performance and may also lead to an increase of pollutant emissions into the atmosphere. All of these effects would have a social, economic and health impact.</span></span></p><p><span><span>In this study we analyze the evolution of extreme hot temperatures on aircraft performance over the main airports in the Southern Euro-Mediterranean region, using simulations performed by regional climate models (RCMs) from the Euro-CORDEX international exercise. To this end, we first evaluate RCMs in terms of their representation of extreme hot temperatures and their trends in the present period by comparing to different observational datasets and also to the driving GCMs. The results of this comparison show that RCMs don't </span><span>represent better the amplitude nor the temporal trends of hot temperature events in summer</span><span>, despide their higher spatial resolution. We assess the changes in the hot temperature extremes from the Euro-CORDEX future projections and we evaluate the risk of weight restriction in the next decades.</span></span></p>