Eye temperature, an indicator for stress levels in young buffalo bulls – A case study of micro-environment modification

The present study was undertaken with an objective to determine diurnal changes of the eye temperature of buffalo young bulls under different shelter management to determine the effect of heat stress. Twenty four buffalo bulls were randomly divided into two groups, each group comprising of 12 animals based on age (16–18 months) and body weight (Control = 301 ± 8.24 kg and Treatment = 311.45 ± 6.24 kg). The control group was housed under normal management practices followed, and the height of the shed was 10 ft. and width was 12 ft. with concrete floor. Whereas, the treatment group was housed in shed having 15 ft. height and 25 ft. width along with rubber mat as flooring and the total area provided for each animal in both the groups was 45.96 sq. feet. They were also provided with dairy fans and mist cooling in day time to ameliorate the heat stress. The thermal humidity index (THI), floor and roof temperature variation of the shed was recorded. The eye temperature of bulls was measured to evaluate the effect of different housing on the animals’ thermal status under hot dry summer conditions.Results revealed that the THI of treatment shed was significantly (P< 0.01) lower than the control at different times. The floor and roof surface temperature of the treatment shed was significantly (P<0.05) lower than the control shed. Diurnal patterns of eye temperature measured in both the groups showed increased eye temperature in control group bulls compared to treatment group. The eye temperature at 7.00 hrs was similar in both groups, whereas it was highly significant (P<0.01) at 13.00 and 19.00 hrs. The heat stress in the buffalo bulls was exhibited by increased eye temperature. Thus, the variation in the eye temperature can be effectively used as an indicator of heat stress and the dairy fans and mist cooling along with rubber mat flooring can be utilized to ameliorate the heat stress in the buffalo bulls.

Analysis of Infrared Radiation Intensity by Water-Mist Spraying in Ship Exhaust System

The infrared radiation intensity in 3~5μm of conventional ship exhaust system are so severe [1] that can be easily captured by detector. Therefore, it’s necessary to take measure like spraying water mist to decrease temperature of exhaust system in order to decrease infrared radiation intensity. In this paper, the calculation of infrared radiation intensity of conventional ship exhaust system with water-mist spraying will be given. The results show that the average and maximum infrared radiation intensity of the exhaust system can be reduced by 90.3% and 95.7% after water mist cooling.

Effect of spray air settings of speed-increasing contra-angle handpieces on intrapulpal temperatures, drilling times, and coolant spray pattern

Objectives Decreasing aerosol leaks are of great interest, especially in the recent era of COVID-19. The aim was to investigate intrapulpal heat development, coolant spray patterns, and the preparation efficiency of speed-increasing contra-angle handpieces with the spray air on (mist) or off (water jet) settings during restorative cavity preparations. Methods Standard-sized cavities were prepared in 80 extracted intact human molar teeth using diamond cylindrical drills with a 1:5 speed-increasing contra-angle handpiece. A custom-made device maintained the standardized lateral drilling force (3 N) and predetermined depth. Temperatures were measured using intrapulpal thermocouple probes. The four experimental groups were as follows: mist cooling mode at 15 mL/min (AIR15), water jet cooling mode at 15 mL/min (JET15), mist cooling mode at 30 mL/min (AIR30), and water jet cooling mode at 30 mL/min (JET30). The coolant spray pattern was captured using macro-photo imaging. Results The JET15 group had the highest increase in temperature (ΔT = 6.02 °C), while JET30 (ΔT = 2.24 °C; p < 0.001), AIR15 (ΔT = 3.34 °C; p = 0.042), and AIR30 (ΔT = 2.95 °C; p = 0.003) had significantly lower increases in temperature. Fine mist aerosol was formed in the AIR15 and AIR30 preparations but not in the JET15 and JET30 preparations (p < 0.001). The irrigation mode had no influence on the preparation time (p = 0.672). Conclusions Water jet irrigation using coolant at 30 mL/min appeared to be the optimal mode. Considering the safe intrapulpal temperatures and the absence of fine mist aerosols, this mode can be recommended for restorative cavity preparations. Clinical significance To increase infection control in dental practices, the water jet irrigation mode of speed-increasing handpieces with coolant flow rates of 30 mL/min should be considered for restorative cavity preparations.

Simulation of Air/Mist Cooling Among Shock Waves and Passing Wakes Interactions in a Transonic Gas Turbine Stage

This paper presents a 2-D numerical investigation of the effect of interactions of moving wakes and shock waves on mist cooling performance over airfoils in the first stator-rotor stage of a transonic gas turbine. The discrete phase model (DPM) is used to simulate and track the evaporation and movement of the tiny water droplets. Breakup and coalescence sub-models are used to simulate the interaction between the droplets themselves. A linear sliding mesh technique is used to study the transient stator-rotor interaction. The results show that the passing unsteady wakes caused by the blade rotation press the mist on the blade suction side flowing near the blade surface, providing more enhanced film cooling effectiveness. The weak oblique shock waves do not exert a significant effect on the air/mist cooling effectiveness. Injecting a 10% mist ratio noticeably improved the cooling enhancement by reducing the wall temperature values up to 200 K in some locations. Injecting the tiny water droplets does not cause a noticeable pressure loss compared to the air-only cooling case. Injecting mist doesn’t alter the effect of shocks.

Air­-Water Mist Cooling Characteristics of an MS Plate in a Laboratory Scale ROT­ - An Experimental Observation

Steels of various grades are ubiquitous in the modern economy. Cooling of steel during the production process is an important deciding factor about its final mechanical properties. This is dependent on the characteristics of the industrial setup and coolant used. Studies have been undertaken for analysis of their influence on the cooling rate, given specific parameters, for suitable industrial use and optimal production. The present study and experiments undertaken highlight the variation of the cooling rate of a Mild Steel Plate in a miniaturized Run Out Table (ROT), using air­water mist spray cooling under different initial plate temperatures and nozzle bank distances.

Possible Perception Bias in the Thermal Evaluation of Evaporation Cooling with a Misting Fan

Mist evaporation cooling (MEC) is increasingly used as a low-energy means to improve thermal comfort in hot environments. However, the thermal sensation votes (TSV) often overshoot values of Predicted Mean Vote (PMV) models. Evaluations of MEC may be affected by an expectation that mist feels cool or the “good subject” effect. Here, subjects are exposed to a misting fan and an identical fan without mist and asked which fan feels cooler. Unknown to the subjects, the misting fan has almost no cooling effect (about 0.4 K reduction in air temperature) and a hidden heater increased the temperature of the misting fan air flow, making it up to 1.6 K warmer than the fan without mist. Supplemental experiments told the subjects about the heater. Surveys of over 300 subjects when varying this misted air temperature showed a bias above random chance that people vote that a misting fan airflow was cooler, even when it was the same temperature or slightly warmer than the non-misting fan. It is possible that the expectation of cooling or good subject effect influences evaluations of mist. This effect should be considered in thermal comfort evaluations of mist cooling and in the deployment of MEC systems.