Sudden Increase In Temperature Research Articles

Kinetic and Thermodynamic Analysis of High-Pressure CO2 Capture Using Ethylenediamine: Experimental Study and Modeling

One of the alternatives to reduce CO2 emissions from industrial sources (mainly the oil and gas industry) is CO2 capture. Absorption with chemical solvents (alkanolamines in aqueous solutions) is the most widely used conventional technology for CO2 capture. Despite the competitive advantages of chemical solvents, the technological challenge in improving the absorption process is to apply alternative solvents, reducing energy demand and increasing the CO2 captured per unit of solvent mass. This work presents an experimental study related to the kinetic and thermodynamic analysis of high-pressure CO2 capture using ethylenediamine (EDA) as a chemical solvent. EDA has two amine groups that can increase the CO2 capture capacity per unit of solvent. A non-stirred experimental setup was installed and commissioned for CO2 capture testing. Tests of the solubility of CO2 in water were carried out to validate the experimental setup. CO2 capture testing was accomplished using EDA in aqueous solutions (0, 5, 10, and 20 wt.% in amine). Finally, a kinetic model involving two steps was proposed, including a rapid absorption step and a slow diffusion step. EDA accelerated the CO2 capture performance. Sudden temperature increases were observed during the initial minutes. The CO2 capture was triggered after the absorption of a minimal amount of CO2 (~10 mmol) into the liquid solutions, and could correspond to the “lean amine acid gas loading” in a typical sweetening process using alkanolamines. At equilibrium, there was a linear relationship between the CO2 loading and the EDA concentration. The CO2 capture behavior obtained adapts accurately (AAD < 1%) to the kinetic mechanism.

Overexpression of seagrass DnaJ gene ZjDjB1 enhances the thermotolerance of transgenic arabidopsis thaliana.

Seagrass meadows are one of the most important marine resources that grow along the coast. They provide habitat and a food source for animals. They also protect the coast, fix sediment and purify seawater. In the current period of global climate change, anomalies in coastal water temperatures are increasing. A sudden increase in water temperature owing to a heat wave can have a profound effect on seagrass. Zostera japonica is a type of intertidal seagrasses, which is exposed to the air at low tide. High temperatures in the summer often lead to a decline in seagrass meadows. DnaJ proteins, also known as J proteins, are a family of conserved chaperone proteins. They are designated as J proteins because they contain a highly conserved J domain. They function as chaperones of heat shock proteins in organisms. In this study, the role of DnaJ protein (ZjDjB1) of Z. japonica under heat stress was studied. ZjDjB1 was localized to the cytoplasm and nucleus. The overexpression of ZjDjB1 in Arabidopsis thaliana results in an increase in thermotolerance and a decrease in the accumulation of reactive oxygen species and also a reduction in membrane damage. ZjDjB1 may achieve this goal by maintaining a low activity of proteolytic enzymes.

Tropical-based EBPR process: The long-term stability, microbial community and its response towards temperature stress.

Temperature is known to influence the operational efficiency of enhanced biological phosphorus removal (EBPR) systems. This study investigated the impact of thermal stress above 30°C on the properties of an EBPR community established with tropical inoculum. The results confirmed the stability of the 30°C EBPR system with high P-removal efficiency over 210 days. Accumulibacter was abundant in the community. When the EBPR sludge was subjected to a sudden temperature increase to 35°C under multiple cycles of anaerobic-aerobic phases, each lasting 4h, high P-removal was maintained over 2days, before gradually failing when the Competibacter appeared to outcompete Accumulibacter. These data suggested that the EBPR capacity is robust when subjected to occasional thermal stress. However, it could not be maintained even for a short time under temperature stress at 40°C. Thus, the threshold temperature for tropical EBPR failure is between 35°C and 40°C. PRACTITIONER POINTS: EBPR was stably maintained at 30°C with Accumulibacter being dominant. Good EBPR activities persisted for a short period at 35°C. EBPR was deteriorated at 40°C. The threshold temperature for tropical EBPR failure is between 35°C and 40°C.

Experimental study on the evolution of pore-fracture structures and mechanism of permeability enhancement in coal under cyclic thermal shock

Heat injection is a new method of recovering enhanced coalbed methane (ECBM). In this study, the impact of a sudden increase in ambient temperature on the permeability of coal was studied, and the application prospects of multiple thermal effects in coal fracturing and permeability enhancement were explored. The permeability and development of pore-fracture structures in coal were tested before and after cyclic thermal shock. The evolution characteristics of the pore distribution were evaluated, and an empirical formula for estimating the permeability growth of coal was established. Digital image processing technology and fractal theory were used to analyse changes in macroscopic fractures. The results indicates that cyclic thermal shock could effectively promote the generation and expansion of permeability pores, effectively connect the relatively independent fracture structures, and break and expand the microfractures and pore groups to form an interwoven fracture network. The increase in cyclic thermal shock resulted in an increase of 0.92%, 1.13%, and 16.15% in total porosity increment, the porosity increment of seepage pores and the proportion increment of seepage pores, respectively, after seven thermal shocks. The permeability of coal exhibited a logarithmic growth pattern with an increase in the number of thermal shock cycles; the average permeability increased by 100.02% after seven cycles. Based on the theory of thermodynamics, the influencing mechanism of cyclic thermal shock on the evolution of pore-fracture structures was explored. Differences were observed in the thermal expansion coefficients of minerals in coal, and thermal stress was generated under cyclic thermal shock, which may lead to damage, promoting fracture formation and increasing permeability. With an increase in the number of thermal shock cycles, the efficiency of permeability enhancement gradually decreased, which suggests that the reservoir conditions should be combined and mining plan should be reasonably set in ECBM extraction using multiple thermal injection techniques.

Assessment of Post-monsoon Drought Over Marathawada Region (Maharashtra, India) Using MODIS Data

Drought is a natural hazard that has a significant effect on the socio-economic, agricultural, and environmental aspects of a region. The Marathwada division of Maharashtra state is infamous for recurring drought situations. Poor precipitation, lack of water storage, relatively high temperature in pre and post-monsoon seasons, and variable unfavorable weather conditions lead to drought in this region. Post-monsoon drought mainly occurs due to deficit rainfall and a sudden increase in temperature. This study represents the overall assessment of post-monsoon drought over Marathwada during October, November, and December for the period 2001 to 2017. Monsoon rainfall deficit results in post-monsoon drought in subsequent months. Detection and monitoring of drought over large areas are possible through remote sensing indices namely, Temperature Condition Index (TCI), Vegetation Condition Index (VCI), and Vegetation Health Index (VHI). VHI is the resultant index from temperature and vegetation indices, which helps to understand vegetation health. During the last 17 years, moderate to severe drought has been observed in two successive years of 2014 and 2015, where TCI, VCI, and VHI indices indicated these years as drought-prone years for the post-monsoon season. Particularly, Bid, Osmanabad, Latur, Nanded, and Parbhani districts suffered severe drought in these successive years. Whereas, all the other years except 2010 and 2017 experienced normal conditions to moderate drought in the Marathwada region. Due to erratic rainfall, it is necessary to plan water utilization and storage in Marathwada to overcome the recurrent drought experienced in the region. This may help agronomists and planners in better management of water resources, particularly for the agricultural sector.

Characteristics of microwave-induced discharge over a biomass-derived char spherical carrier

In this study, a new method of microwave-induced discharge over biomass-derived char (i.e., bio-char) spherical carriers was proposed. Bio-char spherical carriers were obtained through rational forming. The discharge intensity and temperature increase under discharge were measured to elaborate the quantitative relationship between microwave discharge and the temperature increase. The effect of bio-char properties on microwave-induced discharge was investigated. The results revealed that discharge achieved the highest electric–thermal conversion efficiency of 61.04%, and the heat generation ratio through the discharge in the initial 10 min was up to 69.08%. The graphitisation degree and transmission depth of microwaves can affect discharge intensity. A critical light intensity inducing hot spot effect exists under different working conditions, and exceeding the critical value led to the hot spot effect and a sudden increase in bed temperature, with a corresponding range of 2.48–5.76 V. The maximum temperature under microwave discharge reached 981 °C, with a heating rate of 376.4 °C/min. The method is potential in the field of value-added utilization of bio-char and microwave-promoted chemical processes.

Numerical study on convective flow boiling of nanoliquid inside a pipe filling with aluminum metal foam by two-phase model

This study tries to employ the computational fluid dynamics (CFD) approach to investigate the influence of the simultaneous use of the metal foam (porous media) and the water-based nanofluid on the boiling flow regime. For this purpose, boiling flow heat transfer of water-based copper nanofluid inside of both simple pipe and aluminum metal foam pipe is simulated using the Eulerian two-phase CFD model. The nanofluid is supposed to flow inside the pipe with the mass flux of 1927 kg/m2s and the subcooled temperature of 10oc at atmospheric working pressure. The pipe is also under a constant wall heat flux (50–110 KW/m2). Different copper nanoparticle volume fractions (i.e., 0.5, 1, and 1.5%) are considered for this investigation. The porosity and pore density of the metal foam are 0.8 and 10 pore per inch (PPI) respectively. The heat transfer parameters of boiling flow including the wall temperature, the vapor volume fraction on the wall, the onset of the nucleate boiling (ONB), the local heat transfer coefficient, and the mean diameter of the vapor bubble are considered in this study. All heat transfer coefficients predicted by the CFD are compared with the Chen correlation. As far as the authors know, for the first time, the boiling flow of nanofluid-based water inside a metal foam pipe was simulated by the two-phase model of Eulerian. The results reveal that for the metal foam pipe, after happening of the ONB, the wall temperatures suddenly jump over the saturated temperature and the critical heat flux (CHF) happens. But no such sudden increase of the wall temperature is seen along the simple pipe before and after the ONB. Besides, the convective heat transfer coefficient in the metal foam pipe before the beginning of the boiling is more than double the boiling flow in the simple pipe. Although in metal foam pipe, once the boiling happened, the heat transfer coefficient was degraded by 50%, this value is still 25% more than the heat transfer coefficient of the boiling flow in the simple pipe. The results of this study could be practically used for boiling heat transfer analysis of heat exchangers filled by porous media and nanofluid.

Effect of different monomer precursors with identical functionality on the properties of the polymer network

The association between thermo-mechanical properties in polymers and functionality of monomer precursors is frequently exploited in the materials science. However, it is not known if there are more variables beyond monomer functionality that have a similar link. Here, by using simulations to generate spatial networks from chemically different monomers with identical functionality we show that such networks have universal graph-theoretical properties as well as a near-universal elastic modulus. The vitrification temperature was found to be universal only up to a certain network density, as measured by the bond conversion. The latter observation is explained by the fact that monomer’s tendency to coil enhances formation of topological holes, which, when accumulated, amount to a percolating cell complex restricting network’s mobility. This higher-order percolation occurs late after gelation and is shown to coincide with the onset of brittleness, as indicated by a sudden increase in the glass transition temperature.

Engineering Iron Oxide Nanocatalysts by a Microwave-Assisted Polyol Method for the Magnetically Induced Degradation of Organic Pollutants.

Advanced oxidation processes constitute a promising alternative for the treatment of wastewater containing organic pollutants. Still, the lack of cost-effective processes has hampered the widespread use of these methodologies. Iron oxide magnetic nanoparticles stand as a great alternative since they can be engineered by different reproducible and scalable methods. The present study consists of the synthesis of single-core and multicore magnetic iron oxide nanoparticles by the microwave-assisted polyol method and their use as self-heating catalysts for the degradation of an anionic (acid orange 8) and a cationic dye (methylene blue). Decolorization of these dyes was successfully improved by subjecting the catalyst to an alternating magnetic field (AMF, 16 kA/m, 200 kHz). The sudden temperature increase at the surface of the catalyst led to an intensification of 10% in the decolorization yields using 1 g/L of catalyst, 0.3 M H2O2 and 500 ppm of dye. Full decolorization was achieved at 90 °C, but iron leaching (40 ppm) was detected at this temperature leading to a homogeneous Fenton process. Multicore nanoparticles showed higher degradation rates and 100% efficiencies in four reusability cycles under the AMF. The improvement of this process with AMF is a step forward into more sustainable remediation techniques.

Alleviation of Heat Stress in Tomato by Exogenous Application of Sulfur

Temperature is a key factor influencing plant growth and productivity, however sudden increases in temperature can cause severe consequences in terms of crop performance. We evaluated the influence of elementary sulfur application on the physiology and growth of two tomato genotypes (“Ahmar” and “Roma”) grown in two growth chambers (at 25 and 45 °C). Plants were sprayed with 2, 4, 6, and 8 ppm sulfur 45 days after sowing (untreated plants were kept as control). Plants of the “Roma” cultivar receiving 6 ppm sulfur exhibited maximal shoot and root biomass values followed by those receiving 4 ppm under both temperature conditions. Maximal CO2 index, photosynthetic rate, transpiration rate, and greenness index values (188.1 µmol mol−1, 36.3 µmol CO2 m−2 s−1, 1.8 µmol H2O m−2 s−1, and 95 SPAD, respectively) were observed in plants of “Roma” cultivar grown at 25 °C, indicating positive influences of sulfur on tomato physiology. Similarly, sulfur maximized proline, nitrogen, phosphorus, and potassium contents in leaves of both genotypes at both temperatures. The differences between control and sulfur-treated plants grown under heat stress indicate a possible role of sulfur in mitigating heat stress. Overall, our results suggest that 6 ppm of sulfur is the best dose to alleviate tomato heat stress and enhance the morphological, physiological, and biochemical attributes of tomato plants.

Impact of elevated temperature on the physiological and biochemical responses of Kappaphycus alvarezii (Rhodophyta).

The eucheumatoids Kappaphycus and Eucheuma are cultivated in tropical or subtropical regions for the production of carrageenan, a hydrocolloid widely used in the food and cosmetic industries. Kappaphycus alvarezii is a highly valued economic crop in the Coral Triangle, with the Philippines, Indonesia and Malaysia ranked among the largest producers. In the absence of measures to mitigate climate change, extreme events including heatwaves, typhoons, severe El Niño and La Niña, are expected to increase in frequency and magnitude. This inadvertently brings adverse effects to the seaweed cultivation industry, especially in the tropics. Temperatures are rapidly reaching the upper limit of biologically tolerable levels and an increase in reports of ice-ice and pest outbreaks is attributable to these shifts of environmental parameters. Nevertheless, few reports on the response of eucheumatoids to a changing environment, in particular global warming, are available. Understanding the responses and possible mechanisms for acclimation to warming is crucial for a sustainable seaweed cultivation industry. Here, the physiological and biochemical responses of K. alvarezii to acute warming indicated that the strain used in the current study is unlikely to survive sudden increases in temperature above 36°C. As temperature increased, the growth rates, photosynthetic performance, phycocolloid quality (carrageenan yield, gel strength and gel viscosity) and pigment content (chlorophyll-a, carotenoid and phycobiliproteins) were reduced while the production of reactive oxygen species increased indicating the occurrence of stress in the seaweeds. This study provides a basis for future work on long term acclimation to elevated temperature and mesocosm-based multivariate studies to identify heat-tolerant strains for sustainable cultivation.

A study on optoelectronic performance of perovskite solar cell under different stress testing conditions

Since the inception of perovskites in the light absorbing region of solar cell, perovskite solar cell (PSC) have come a long way from a mere power conversion efficiency (PCE) of 3.8% in 2009 to 25.2% in 2019. The sudden growth in efficiency is riddled with instability issues caused by myriad extrinsic and intrinsic factors like moisture, heat, cell configuration etc., which would prove difficult for commercial scalability of the cells. Like other commercially established photovoltaic cells, PSCs have to pass certain stress tests before it can be deemed commercially viable. In the present study, we have focussed on three main types of stress testing on perovskite solar cells, 1) Damp heat test (i.e. solar cells were exposed to high humidity (RH>85%) and high temperature (85 °C) simultaneously, 2) Thermal stress (sudden increase and decrease in ambient temperature with a ramp rate of 65 °C/h) and 3) Outdoor aging under natural diurnal conditions for 504 h. Our results show that the PSCs are more susceptible to accelerated degradation under damp heat test due to the combined effect of heat and moisture retaining less than 1% of initial PCE. Under lower humidity levels, they managed to retain ~70% of initial PCE. Moreover, cells had ~37% of initial PCE towards 504 h of outdoor exposure. Temperature dependence on resistances of the cell was also studied under thermal stress conditions. Our results and analysis would be helpful for those interested in developing or designing a consensus on testing PSCs before paving its way for commercialization.

Visualization of pool boiling and occurring critical heat flux on coiled wire

Pool boiling is used in various industries and play a significant role in heat transfer. So far, multiple studies have been carried out on investigating boiling and applying heat flux on the wire. In the present paper, the boiling of the coiled wire under atmospheric pressure conditions has been investigated. The fluid temperature inside the pool is considered under both constant (equal to saturation temperature) and variable temperature conditions. The value of the ring density in the coiled wire is considered to be variable. Based on the results, changing the pool liquid temperature changes bubble departure diameter and frequency. Also, increasing the density of the coil ring increases the diameter of bubbles. It has been observed that the bubbles are usually formed inside the coil, and after moving to the two ends of the coil, they leave the coil. However, by increasing the amount of heat flux and the pool liquid temperature, the size of bubbles will be larger; therefore, the bubbles must leave the coil from the empty spaces between the rings. By increasing the amount of applied heat flux, the coil was enclosed in a layer of vapor, which results in a decrease in the amount of heat transfer coefficient, and finally, a sudden increase in temperature on the wire will occur, which indicates the critical heat flux. Also, it has been observed that the critical heat flux always arises in the coil region of wire and not in the straight part of the wire.

Application of Iot with Motion Sensor for Smart Learning Environment

Considering the estimate of the potential system in the classroom, lights and fan control is expected to be performed in three modules. Thus, in the case of light and ventilator power, occupancy sensor is used to estimate the amount of output voltage increases in the diode while the rotational speed increases simultaneously. Motion sensors are common where safety and energy efficiency are concerned. They can be used for burglary alarms or surveillance cameras, which activate such devices when it detects nearby motion. This can be an energy saver by turning off lights in a building as it no longer detects activity and is commonly used in office buildings and toilets. The PIR is a motion sensor that you might have seen when you enter a bathroom or office space, normally with a white mask. They are lightweight, low powered, simple to use and low cost. The way it detects motion is by sensing the temperature differences between the surroundings PIRs are fitted with a passive sensors level of infrared radiation –all emits some low-level radiations, but a human body emits good heat. This triggers a pulse when the sensor senses a different shift between the two slots which is what it detects as ‘movement’ Technology is available that combines both PIR and microwave sensors to have less false alarms, a sudden increase in room temperature will cause the PIR to go off while wind will push an object and activate the microwave sensor.

Simulation of the Electrochemical and Thermal Properties of Electric Vehicle Power Batteries

The optimal energy and power performance of lithium ion batteries can be attained if a suitable thermal battery management system is used. Furthermore, to ensure the safe operation, a well functioning temperature control method, is needed. To achieve these goals, the simulation software COMSOL Multiphysics used to construct a three-dimensional electrochemical/thermal model of a monomer lithium ion battery. The simulation makes it possible to study the thermal characteristics at different ambient temperatures and different discharge rates. The obtained main outcomes are 1) The temperature of the lithium ion battery increases with increasing discharge ratio, and a sudden temperature increase is observed for higher discharge ratios, 2) For constant discharge rates, the temperature increase of the battery occurs mainly in the positive and negative electrode region, while lower temperatures are observed in the center and lower-edge region. A comparison between simulation and obtained date, indicates that the three-dimensional electrochemical/thermal model of the monomer lithium ion battery described the lithium ion battery well in terms of both heat generation and heat transfer.

Gene expression differences between abalone that are susceptible and resilient to a simulated heat wave event

Sudden increases in water temperature can lead to mortality of cultured and wild mollusc communities during the summer months. The frequency and severity of mortality events are expected to increase as climate changes. The molecular basis for individual survival ability is poorly understood. To better understand signatures and mechanisms affecting survival we analyzed the gene expression profiles of greenlip abalone (Haliotis laevigata) classified as susceptible or resilient to laboratory induced heat stress both prior to, and at three time points throughout, the heat stress event. We detected 487 genes that were significantly differentially expressed between resilient and susceptible abalone (28 of these were significantly differentially expressed over all three time points and 26 were significantly differentially expressed throughout two of the three heat stress trial sampling points). These 54 genes also demonstrated a similar relative expression level difference between resilient and susceptible abalone in samples collected six months prior to the heat stress event. Three distinct co-expression networks incorporating these genes were also identified. The most informative transcriptomic differences between resilient and susceptible abalone throughout the heat stress trial were associated with metabolism (e.g. Mitofusin 1) and immune process (e.g. Multiple epidermal growth factor-like domain 10, Lysozyme). These functional mechanisms may enable resilient individuals to endure heat wave events. These signatures could be used to predict an individual's resilience. The findings have application in aiding stock selection for the aquaculture industry, to provide greater resilience to global climate change.

A review of heat stress signaling in plants

The threat and crisis of food due to global warming has a related with global climate change. The threat of a decline in food production in various countries by climate change triggers a long drought. The increase in temperature causes heat stress on the plant which has an impact on the decline in land quality and others. Heat stress is often defined as an increase in temperature for a certain period of time, which can cause irreversible damage to plants, which generally occurs at temperatures of 10-15°C above the threshold. Heat stress is a major factor limiting crop productivity and adaptation, especially when extreme temperatures coincide with the critical stage of plant growth. Heat stress is a major factor limiting crop productivity and adaptation, especially when extreme temperatures coincide with the critical stage of plant growth. Excessive heat can disrupt by denaturing enzymes and damaging metabolism so that changes occur in the morphological structure, phenology, physiology and molecular plants. The response to increase in temperature of 5-10° C, makes plants produce a unique protein called heat shock proteins (HSP). An increase in HSP production occurs when plants experience a sudden or gradual increase in temperature. HSP is released when the stress of exposed to plant. Under these conditions HSP is useful for protecting proteins and causes resistant plants. The resistance obtained by heat shock is different from the resistance obtained by rapid growth at moderately high temperatures. This difference is presumed by the presence of HSP responses induced by heat stress. The HSP can play a role as a sign of gene stress and activation and in regulating oxidation reactions in cells. Utilization of heat stress signaling in food crops breeding can be used to development Wheat Tolerance to High Temperature.

A theoretical and experimental study of extinguishing compressed air foam on an n-heptane storage tank fire with variable fuel thickness

Compressed air foam (CAF) is an environment friendly fire extinguishing technique being used around the world since the ban of halogen-based agents. In this work, its extinguishing behavior on a radiation-controlled storage tank fire was firstly investigated based on the controlling mechanism of burning rate. A formula of burning rate after foam discharge is deduced. It was found that the oleophobic effect of fluorocarbon surfactants, the increased foam layer thickness and lower diffusion coefficient had coupled chemical and physical effects on extinguishing, which outweighed the cooling effect of foam evaporation. Due to the properties of CAF, a special phenomenon of the sudden increase in the flame temperature and radiation after foam discharge was analyzed. The increase in foam spreading length with time was found to still abide by a power law under fire conditions. A concept of effective and total extinguishing time was suggested, both of which reduce with a rising foam flow rate, but the reduction rate decreases at higher flow rate. In addition, the foam dosage with flow rate had a U-shaped curve at total extinction. For the case of lower fuel thickness, its burning rate was lower and the extinguishing time was longer.

New insights into the Pt(hkl)-alkaline solution interphases from the laser induced temperature jump method

The interfacial properties of platinum single crystal electrodes in contact with alkaline aqueous solutions (pH = 13) have been investigated using the laser induced temperature jump method. This technique offers insights into the net orientation of water dipoles in contact with the electrode surface by recording the coulostatic potential changes after a sudden increase of the interfacial temperature in the submicrosecond time scale. This information is intimately related with the magnitude and sign of charge separation at the interphase and the resulting electric field. In all cases, water shows a net orientation with the hydrogen towards the metal at the lowest investigated potential value, reflected in negative potential transients. The magnitude of the water orientation decreases as the applied potential increases. Eventually, the sign of the potential transient changes, reflecting a reorientation of the water dipoles. The potential where such inversion takes place follows the order Pt(110) < Pt(100) < Pt(111) in accordance with the observed behavior in acid solution and the trend of the work function. For Pt(111) the change of sign of the laser induced potential transient takes place at the onset of hydroxyl adsorption. For the three surfaces, when the pH is decreased to ca. pH = 11, a slow response is detected at potentials values above the inversion point. This could be due to a fast adsorption process or to a slow reorientation of water. After the introduction of steps on the (111) terrace, the inversion shifts to the double layer region, allowing the unambiguous identification of the inversion with a change on the net orientation of the water molecules. For stepped surfaces, a second inversion of the laser induced potential transient is observed that could be related with an effect of the local charge on steps disrupting the ordering of the water network. Comparison with analogous results in acid solution gives information about the local distribution of charges on the stepped surfaces.

The effect of intermittent feeding and cold water on performance and carcass traits of broilers reared under daily heat stress.

ObjectiveThis study aimed to determine the effect of intermittent feeding and cold water on performance and carcass traits in broiler chickens between 4 to 6 wk of age exposed to daily high temperature.MethodsBroilers were assigned to four treatment groups according to a 2×2 factorial design between 22 to 42 d of age (80 broilers per treatment, 4 replications). Broilers were divided into two main groups as feeding type (ad-libitum [AL] and intermittent [IF] for 6 h daily) and sub-groups as water temperature (normal [NW], 24.9°C and cold [CW], 16.4°C). Heat treatment was applied between 11.00 to 17.00 h daily between 22 to 42 d of age.ResultsLive weight at 6th wk was not affected by feeding type and water temperature, but the live weight was significantly higher in IF chickens at the 5th wk (p<0.05). Average weekly gain of IF broiler chickens were higher compared to AL group at 4, 5, and 6 wk of age (p< 0.05). Although feeding type did not affect feed intake in 4 and 5th wk, feed intake was higher in IF chickens at 6th wk (p<0.01). In addition, feeding type and water temperature did not affect feed conversion ratio and interactions were not significant (p>0.05). Water temperature had no significant effect on heart, liver, gizzard, and abdominal fat percentages (p>0.05).ConclusionIt is concluded that IF increased the average weekly gain in chickens reared under daily heat stress for 6 h between 22 to 42 d of age. IF in hot environmental conditions slightly increased performance without adversely affecting health, welfare, and physiological traits, whereas CW implementation had no significant effect on performance. It can also be said that IF suppresses a sudden increase in body temperature depending on age and live weight.