Cyclic Process Research Articles

IMPROVING STUDENTS’ LISTENING COMPREHENSION THROUGH YOUTUBE AT SMK MITRA NUSANTARA JATIBENING BARU PONDOK GEDE – BEKASI IN ACADEMIC YEAR 2023/2024

This study aims to determine the effectiveness of using YouTube as a medium to enhance English listening comprehension among students at SMK Mitra Nusantara, Bekasi, during the 2023/2024 academic year. Conducted as Classroom Action Research (CAR), the research involved a cyclical process of planning, action, observation, and reflection, targeting 25 students from class XI TKR. The data collection methods included observation and listening comprehension tests, analyzed through both qualitative and quantitative approaches. The results indicated a significant improvement in students' listening comprehension, as evidenced by the increase in average test scores from 70.4 in the pre-test to 71.92 in Cycle 1, and 81.24 in Cycle 2. Additionally, the number of students meeting the minimum competency criteria rose from 11 in the pre-test to 16 in Cycle 1 and 22 in Cycle 2. Qualitative observations also revealed heightened student engagement and motivation when using YouTube in the classroom. This study recommends that integrating YouTube into listening instruction can serve as an effective strategy for enhancing listening skills at the vocational high school level.

Studies on Multifunctional Nanostructured Materials

Multifunctional materials are of today’s quest. Miniaturization, i.e. development of these materials in the form of nanomaterials is of primary need considering their application in devices. Moreover, if these are obtained in nanostructured form, they can bring wonders. We have adopted a method for developing multiferroic BiFeO3 (BFO) with simultaneous antiferromagnetic, ferroelectric & ferroelastic behaviour in form of nanostructures like nanorods, nanowire etc. by employing Anodised Alumina (AAO) template with various pore sizes from 20nm with solution route followed by controlled vacuum filtration and sintering. Diameters of nanorods are in the range of 20-100 nm as observed by FESEM. Capacitance assayed by cyclic voltammetry (CV) and charge discharge processes reveals a very high value of specific capacitance of 450F/gm. Capacitance has been estimated by extrapolating the charge collected at the electrode to that at scanning rate of infinity which is relevant for the charge collected at the nanorods protruding out of the template. Charging and discharging times are quite constant over a large number of cycles. This large value of specific capacitance can be attributed to the nanostructure form of BFO nanorod. The high value of specific capacitance of BFO nanorods brings forth its use as electrode in storage energy devices. Also, a high value of polarization as well as a significant magnetic susceptibility are observed in multiferroic Bismuth Ferrite (BFO) in the form of nanorods protruding out. The high values of polarization and magnetic susceptibility are attributed to the structured form of BFO nanorods giving rise to the directionality. There is no leakage current in P-E loop examined at various fields and frequencies. Magnetocapacitance measurements reflect a significant enhancement in magnetoelectric coupling also.

Backward induction-based multi-layer approach for watershed flood management in arid regions

Managing floods in interconnected nonurban and urban areas of arid regions prone to flash floods requires a more dynamic and integrated approach than traditional linear methods. In this regard, this study proposes a novel multi-stage decision-making framework which reshapes the traditional cascade approach to flood management by addressing the interdependencies between upstream and downstream regions. The proposed cyclic decision-making process involves five main steps: First, the Hydraulic and Hydrological (H/H) conditions in urban and nonurban areas were modeled using the SWMM. Then, a multi-stage optimization framework was constructed, in the first step of which the detention dams' location and dimensions were optimized in the nonurban area. Next, to link the first and second stages of the optimization, COPRAS method was employed for selecting the critical upstream management strategies. These strategies were determined as the input for the flood network optimization in the second stage. Finally, the Backward Induction Game Theory (BIGT) method was employed to find the best management strategy, under which not only the upstream conditions were considered in downstream flood protection but also stakeholders' conflicts were totally resolved by choosing the Nash Equilibrium. Our findings revealed that the implementation of the selected scenario could reduce flood peaks at the entrance of urban areas by 60.7 % and enhance shock absorption by 81.8 %. In fact, we guarantee that it is possible to propose a scenario encompassing drainage and detention dams' characteristics that, in addition to resolving stakeholders' conflicts of interest, can reduce the risk of flooding in complex watersheds. Moreover, the framework transforms the sequential, one-way cascade decision-making process into a continuous cycle, where upstream and downstream's H/H conditions and stakeholders' preferences are evaluated in coordination to achieve an agreement. Also, this framework helps decision-makers access the most sustainable solutions considering hydrological and socio-economic points of view.

Analysis of pyroelectric properties in quenched NBT-BT composition

Quenching has recently demonstrated its efficacy in elevating the ferroelectric to relaxor phase transition temperature (TFR) in 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-6BT). Consequently, the current investigation comprehensively examines the pyroelectric properties of quenched NBT-6BT. The pyroelectric coefficient is measured using the Byer-Roundy method, incorporating a strategic approach to mitigate the risk of overestimation by implementing cyclic heating and cooling. Quenching enhances the depolarization temperature (Td) by approximately 40 °C, quantified through the temperature-dependent pyroelectric current density (Ip). The maximum pyroelectric current (52nA) and voltage (200V) responses to thermal cycling (15s heating/cooling) were observed in quenched NBT-6BT. The voltage sensitivity figures of merit were equivalent for both furnace-cooled and quenched NBT-6BT. The assessment of pyroelectric energy storage involved charging a 48 nF capacitor in 180s, resulting in a maximum voltage of 38V. The outcomes strongly endorse the quenched NBT-6BT as an efficient pyroelectric material, showcasing promising attributes for applications in sensing and energy harvesting across a broad temperature range.

고령자의 구직 여정: 질적연구 접근

Despite the significant number of older adults in South Korea seeking employment for livelihood maintenance, researchers have not given sufficient attention to elderly workers, and studies on their job search experiences remain scarce. This study draws on a self-regulation perspective on job search models to explore the job search patterns and internal experiences of older job seekers, aiming to gain a deeper understanding of their experiences during the job search process. We conducted a qualitative study based on in-depth interviews with 11 older job seekers in South Korea. The results indicate that older job seekers face disadvantageous job search environments due to age-discriminatory employment practices, intergenerational job competition, and limited access to information. These factors seem to restrict their employment options both qualitatively and quantitatively. Older job seekers, desperate for employment to maintain their livelihood, experience anxiety during the job search process but persist through self-regulation strategies. Even after gaining employment, they struggle with job insecurity and vulnerability. In response, they employ various emotional and cognitive regulation strategies, including self-blame, cognitive reappraisal, and downward comparison. However, upon job termination, they repeatedly return to the disadvantageous job search environment, creating a cyclical process.

An automatic eddy detection algorithm based on quadrant angle of velocity vector and its application

ABSTRACT Eddies assume a pivotal role in both the oceanic heat cycle and marine dynamic processes. The development of real-time satellite observations, coupled with advancements in computer intelligence, has propelled automatic eddy detection algorithms to the forefront of ocean remote sensing research. Nevertheless, target omissions and accuracy degradations are inevitable for multiple detection algorithms due to strong morphological variations in ocean eddies. This paper proposes an automatic detection algorithm based on the quadrant angle of the velocity vector in the flow field. Firstly, a rectangular search box is established, and the corresponding quadrant angles at the four vertices are calculated. Secondly, the centres and types of eddies are determined according to the cumulative sum and variety rules of quadrant angles. Then the outermost boundary is identified by regularity of quadrant angles in eight directions expanding outward from the centre of the eddy using the stream function equation. The new algorithm is assessed and verified using geostrophic flow data derived from the CMEMS standard gridded sea level anomaly product. Furthermore, its detection capabilities are demonstrated through a comparative analysis with several other algorithms. All methods exhibit consistent efficacy in detecting the majority of eddies with similar spatial distributions. In cases where the new algorithm identifies a specific eddy not detected by the FF15 and ND10 algorithms, sea surface temperature data is employed for verification. The sea surface temperature distribution map, along with the obtained results, illustrates the superiority of the new algorithm and its adaptability to products with varying resolutions. Additionally, the results undergo verification through a manual detection method, revealing that the new algorithm achieves SDR of 91.73% and an EDR of 3.54%. This percentage significantly surpasses the lower acceptable limit of 80% for the SDR parameter. The new algorithm is applied to study eddies with lifetimes exceeding ten days, spanning from March 2022 to February 2023, within the East China Sea and the South China Sea. The radius of SCS eddies is generally larger than that of ECS eddies, both cyclonic and anticyclonic. This further confirms the significant influence of regional ocean dynamics on the structure of eddies in different regions. Finally, the algorithm is applied to SWOT data to test the adaptability of the algorithm to non-regular grid data. The results show that the algorithm can effectively analyse SWOT data within 60° latitudes.

Frequency-dependent ferroelectric heat cycles in polymer blends: Enhancements in electrocaloric performance of P(VDF-TrFE) and P(VDF-TrFE-CTFE)

Copolymer (P(VDF-TrFE-CTFE)) and terpolymer (P(VDF-TrFE)) have been widely investigated for their promising electrocaloric effect (ECE), whereas, their mixture of ECE has not been investigated. In this work, P(VDF-TrFE was mixed with a variety of concentrations of P(VDF-TrFE-CTFE) and its ECE effect was investigated in detail. Results indicated that after mixing of the copolymer, an additional change of adiabatic temperature (T + Tad) could be obtained. Moreover, the energy density (ND) is drastically enhanced when the copolymer concentration increases up to 3 % due to antiferroelectric behavior of polymer blends (i.e. Copolymer content = 30 wt%). In addition, we observed that we can tune the working of frequency dependent ferroelectric heat cycle instead of pyroelectric heat cycle by changing the operational frequency in antiferroelectric range and the rejection of output heat is increased by decreasing the operational frequency (from 10−2Hz to 102 Hz). And we propose to use ΔT Vs E loop as the criteria to explain the ferroelectric heat cycle. Using this novel technique, we could successfully compare the efficiency of heat cycles. Three times higher efficiency of ΔT-E loop at low frequency (10−2 Hz) was achieved due to the blend's antiferroelectric behavior.

Dynamics of deposition and removal of a fluorocarbon film in the cyclic process of plasma-chemical etching of silicon

In situ measurements of the dynamics of deposition and etching of a fluorocarbon film (FCF) during cyclic plasma-chemical etching of silicon using a laser interferometer have been carried out. Direct measurements of the deposition and etch rates, as well as the etch time of the FCF, open up new possibilities for optimizing the cycle procedure. For example, adjusting the etching time of the FCF improves the selectivity of the etching process.

Experiences of parents of children with mental illnesses: A systematic review and meta-ethnographic synthesis.

In this paper, we present a qualitative meta-ethnographic synthesis of 26 articles reporting experiences of subjective burden in 389 parents of children with mental illnesses. The studies were identified through a systematic literature search of PubMed, CINAHL Ultimate, APA PsycInfo, and MedLine Ultimate. We conducted a quality appraisal and followed the seven stages of meta-ethnographic synthesis. We developed a line of argument synthesis in the form of a model that depicts the subjective, temporal, and psychological experiences of parents. The model proposes a cyclical process characterized by five stages, each depicting a transitional point in which parents re-evaluate their experiences: caring for an intimate stranger; turning point; unavoidable role; uncertain future; transcendence. This model highlights the complex psychological processes that parents endure when caring for a child with a mental illness. The review highlights several methodological issues in this field of research, including issues related to sampling, poor reporting of data analysis, limited critical appraisal, and a lack of reflexivity. Future research should address the gaps in the literature while also attending to the issues that have been highlighted by this review.

Assessment of Dairy Farmers' Knowledge Regarding Good Dairy Farming Practices in Uttar Pradesh, India

Dairy farming is essential for households with low and moderate-income, serving as a crucial component of both subsistence and commercial farming. The dairy sector holds significant potential and offers ample opportunities to enhance the socio-economic status of farmers due to its ability to generate higher productivity and profits within a shorter timeframe compared to other businesses. The study was conducted to measure dairy farmers' knowledge level regarding good dairy farming practices in Uttar Pradesh. Being the highest milk-producing state in India, Uttar Pradesh was selected purposively for the study. Further selection of districts, blocks, and villages for two each was done randomly. While selecting respondents, 10 percent of dairy farmers from the total household of each village were considered under a proportionate random sampling method. The criteria of the respondents were the dairy farmers should have at least one lactating dairy animal at the time of investigation. From the study, it was observed that 64.85 percent of respondents had knowledge about how many days is the colostrum-free milk available from animals and 81.21 percent of respondents knew about animals going to repeat their heat cycle. The majority (97.88%) of respondents had knowledge about colostrums feeding to newborn calves and 62.42 percent respondents had knowledge about special bedding for newborn calves. 84.24 percent of respondents had knowledge about ill animals and 56.36 percent of respondents had knowledge about the proper disposal of dung. 94.24 percent of respondents knew how many workers manage 5 animals on their farm. 48.79 percent of respondents had overall knowledge about good dairy farming practices. Study identified require a clear strengthening of extension services through targeted training programs to improve the knowledge of key practices among the farming community. Another low awareness is about schemes by the government on support to farmers in terms of finances and technical means. This can be improved through better communication channels by working with local cooperatives and NGOs.

Competitive oxidation mechanism endows MXene-based supercapacitors with high-temperature tolerance and self-healing capability

MXenes emerge as promising candidates for supercapacitors due to their tunable surface chemistry and high conductivity. However, high temperatures can accelerate MXenes oxidation when exposed to air, limiting their application in supercapacitors for extreme environment operations that require high-temperature tolerance. In this work, we propose introducing bentonite nanosheets between Ti3CNTx MXene layers to suppress the high-temperature oxidation of Ti3CNTx films via a competitive oxidation mechanism, and develope a matched self-healing solid-state bentonite-based electrolyte capable of spontaneously restoring its ionic conductivity after high-temperature dehydration. The Ti3CNTx/bentonite films demonstrate exceptionally high thermal stability at temperatures of up to 600 °C when exposed to air. The solid-state supercapacitors assembled using Ti3CNTx/bentonite films and the bentonite-based electrolyte achieve a high areal capacitance of 22.8 mF cm-2 and demonstrate high-temperature tolerance, exhibiting the ability to self-heal and recover the charge storage performance even after multiple cycles of heating to 300 °C and air cooling. This work could pave the way for the application of MXenes in high-temperature tolerant and self-healing supercapacitors with enhanced longevity.

Covalent Organic Frameworks with Regulated Water Adsorption Sites for Efficient Cooling of Electronics.

The excessive heat accumulation has been the greatest danger for chips to maintain the computing power. In this paper, a passive thermal management strategy for electronics cooling was developed based on the water vapor desorption process of the covalent organic frameworks (COFs). The precise regulation for the number of carbonyl group and the ratio of hydrophilicity and hydrophobicity within pore channels was achieved by water adsorption sites engineering. In particular, COF-THTA with abundant water adsorption sites exhibited highest water uptake and desorption energy, which facilitate efficient cooling of electronics. In proof-of-concept testing, COF-THTA coating (40 × 40 mm) provided a temperature drop of 7.5 °C in 25 minutes at a heating power of 937.5 W/m2, and remained stable after 10 intermittent heat cycles. Furthermore, the equivalent enthalpy of COF-THTA coating can reach up to 1136 J/gcoating. In real application scenarios, COF-THTA coating improved the performance of two real computing devices by 26.73% and 22.61%, respectively. This strategy based on COFs provides a new thinking for passive thermal management, exhibiting great potential in efficient cooling of electronics.

Ultra Stable X‐Ray Imaging Through a Mutually Reinforcing Strategy Between Perovskite Nanocrystal‐Polymethyltrifluoropropylsiloxane

AbstractThe instability of halide perovskite nanocrystals (PNCs) and related composite polymer films posed considerable challenges for application in flexible optoelectronic devices. Herein, perovskite nanocrystal‐polymethyltrifluoropropylsiloxane (PNCs‐PMFS) composites are developed that exhibit outstanding optical stability and irradiation resistance through a mutually reinforcing strategy. The photoluminescence (PL) intensity of PNCs‐PMFS remained stable after four heating cycles, whereas perovskite nanocrystal‐polydimethylsiloxane (PNCs‐PDMS) composites exhibited a 31% decrease in PL intensity. Moreover, PNCs‐PMFS demonstrated superior luminescence stability under UV and X‐ray irradiation due to strong ion‐dipole interactions between PNCs and trifluoromethyl (CF3) dipoles. Under γ‐ray irradiation (300 kGy), PNCs‐PMFS retained 73% (2.86 MPa) of the initial mechanical strength, while PMFS without PNCs retained only 51%. This enhancement is attributed to the effective reduction of free radical concentration in the system by PNCs, as confirmed by electron spin resonance (ESR) and curing curve. Density‐functional theory (DFT) calculations further indicated that PNCs adsorbed free radicals, thereby facilitating interfacial charge transfer and forming a stable resonance structure. These advancements enabled PNCs‐PMFS to serve as scintillation screens for X‐ray detection and imaging, achieving a spatial resolution of 19.0 lp mm−1 and a detection limit of 3.78 µGy s−1, offering novel insights for designing of X‐ray detectors in high‐energy radiation environments.

First field application of functionalized nanoparticles-based nanofluids in thermal enhanced oil recovery: From laboratory experiments to cyclic steam stimulation process

The increasing global demand for fossil fuels and the depletion of light crude oil reserves have driven the petroleum industry to focus on exploiting heavy crude oils, which present significant challenges in recovery and processing. To address these challenges, enhanced oil recovery (EOR) technologies are being developed, with a strong emphasis on advances in catalysis and nanomaterials science. This research significantly contributes to developing new technologies for petroleum exploitation by introducing a novel nanofluid designed to facilitate in-situ upgrading of heavy oil, improving its quality for downstream refining and fuel production. The nanofluid, engineered to enhance the productivity of a heavy oil reservoir under cyclic steam stimulation, targets improvements in oil recovery and fuel-quality indicators such as API gravity and viscosity. Laboratory tests demonstrated the nanofluid’s capability to reduce oil viscosity, improve oil mobility, and selectively interact with heavy oil fractions like resins and asphaltenes. Displacement tests simulating steam injection conditions showed an improvement in oil recovery, increasing from 56 % to 76 % after nanofluid application. The treatment also led to a notable increase in API gravity, from 11.6° to 29.2°, and a significant reduction in viscosity, from 39,987 cP to 104 cP, indicating enhanced crude oil quality, critical for refining and fuel production. Field trials in two wells in Colombia demonstrated the nanofluid’s practical effectiveness, with production increases averaging 97 % and incremental yields of 11,966 barrels in well A and 3213 barrels in well B. Post-treatment, the crude oil exhibited sustained improvements in quality, with API gravity increasing from 11.6° to 13.4° and viscosity decreasing from 39,987 cP to 11,734 cP. These results confirm the long-term durability of the nanofluid’s effects and its potential to enhance fuel production from heavy oil reservoirs. Additionally, the field trial indicated a 48 % reduction in operational costs, primarily due to decreased steam generation and lower CO2 emissions, highlighting the environmental and economic benefits of nanofluid technology for petroleum exploitation.

Meat quality of chickens subjected to cyclic heat stress while supplemented with ZINC-L-SELENOMETHIONINE

A significant additional benefit of incorporating organic forms of selenium into poultry diets is the substantial improvement in the nutritional quality of the meat. This study aimed to investigate gradual inclusions of Zinc-L-Selenomethionine in the diet of broiler chickens from one to 42 days of age, reared under cyclic heat stress conditions, and its effects on carcass traits, breast myopathies, quality, and composition. A total of 1,000 one-day-old male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg of Zn-L-SeMet per kg of feed, with each group consisting of ten replicates of 20 birds. The carcass traits were unaffected (p ≥ 0.102). All scores of breast myopathy incidence (from 0 to 3) were affected by the treatments (p < 0.05). For wooden breast, the inclusion of 1.30 mg provided breasts with a lower incidence. Breasts from the 0.15 mg treatment had a lower incidence within the severe and extreme White striping scores. The treatments had no significant effects on the breast meat quality (p ≥ 0.180), lipid peroxidation (p ≥ 0.172), or composition (p ≥ 0.383). Including 1.30 mg of Zn-L-SeMet for broiler chickens results in better scores of 0 for wooden breast. For white striping, supplementation from 0.15 mg of Zn-L-SeMet reduces the incidence of score 3.

Enzyme-Assisted Solid-Phase Microextraction Coupled with a DNA Nanowalker for Dual-Amplified Detection of Chloramphenicol in Animal-Derived Food Products.

Chloramphenicol (CAP), an aminoalcohol antibiotic, exerts its action on bacterial ribosomes, thereby obstructing protein synthesis. However, the use of CAP in husbandry may lead to its excessive accumulation in animal-derived food products. This presents potential risks to consumer health. This study developed a novel dual-amplification fluorescence detection method by integrating enzyme-assisted solid-phase microextraction (SPME) with a Fe3O4@Au NP-based DNA nanowalker for the detection of CAP in food. The combination of a quartz rod-based SPME biosensor and DNA nanowalker effectively eliminated matrix interference, enabling the conversion of CAP and enhancement of detection signals through two cyclic amplification processes. The strategy demonstrated high sensitivity with a limit of detection of 28.1 aM as well as a wide linear range from 0.1 fM to 1 nM (with R2 > 0.99). This method also demonstrates robust stability and accuracy in detecting trace amounts of CAP in both authentic and prepared positive samples.

The heating effect analysis of electromagnetic induction heating system based on the multi objective optimization strategy

Lithium-ion battery heating in cold weather is necessary to ensure its low-temperature performance and lifetime, so the multi objective optimization heating strategy based on the non-dominated sorting genetic algorithm II is introduced to improve the heating effect of electromagnetic induction heating system, in which the generated Pareto frontier as the research sample is input in K-medoid algorithm in order to reduce the feasible range of solution sets and then get the optimal induction coil parameters combination, and the temperature rise and terminal voltage output performance of battery are characterized by the electrochemical-thermal coupling model. Firstly, under the optimal parameters combination (N = 180, f = 9 kHZ, IA = 6 A), the battery can be heated from 243.15 K to 293.15 K in 1430 s with the temperature difference of 2.74 K, and the temperature field is mainly generated by the heat conduction from active material to mandrel during the heating process due to skin effect and material property. Secondly, the internal resistance is decreased by more than 3 times after the heating, giving rise to the substantial improvement of energy output ability. Finally, neither noticeable discharging capacity retention loss nor apparent voltage output difference is founded after the 200 repeated heating cycles, as compared with the normal charging-discharging cycle at 293.15 K, so the heating strategy has almost no effect on the battery aging and lifetime deterioration. Therefore, the proposed heating strategy can realize a suitable tradeoff among temperature-rising effect, lifespan and low-temperature operating performance, which has substantial potential to be a feasible method for improving the applicability of electric vehicles in a cold weather.

Numerical study of shell and tube thermal energy storage system: Enhancing solidification performance with single-walled carbon nanotubes in phase change material

The coupling of Organic Rankine Cycle (ORC) and Latent Heat Thermal Energy Storage (LHTES) is a novel strategy for efficiently using solar energy. The objective of this study is to explore the solidification performance of phase change material (PCM) with single-walled carbon nanotubes (SWCNTs) for thermal management in solar energy system. The evolution of temperature and liquid fraction during the solidification process is investigated across four cases: Case 01 without SWCNTs, and Cases 02, 03, and 04 with 2 %, 3 %, and 4 % SWCNTs dispersion, respectively. By analyzing the temperature and liquid fraction contours over time, the impact of SWCNTs concentration on thermal performance is assessed. Case 01 has a total solidification time of 14,400 s. In comparison, Case 02 achieves solidification in 13,600 s, Case 03 in 13,040 s, and Case 04 in 12,500 s, reflecting time savings of 5.55 %, 9.44 %, and 13.2 %, respectively. Additionally, Case 04 exhibits the highest sensible heat release of 527.9 kJ and a total heat energy release of 2851.09 kJ. The dimensionless TES rate P′ for Case 04 is 1.26, indicating a 26 % improvement in thermal energy storage performance over the baseline. These findings underscore the effectiveness of SWCNTs-enhanced PCM in optimizing solar energy systems through enhanced heat transfer and accelerated solidification.

Origins of Extreme CAPE Around the World

AbstractSevere convection, responsible for hazards such as tornadoes, flash floods, and hail, is usually preceded by abundant convective available potential energy (CAPE). In this work, we use a Lagrangian approach to study the buildup of anomalously large values of CAPE from 2012 to 2013 in various regions. Nearly all extreme values of CAPE arise from surface fluxes underneath a layer of convective inhibition (the CIN layer) over several diurnal cycles, but the origin of the CIN layer and the diurnal cycle of surface fluxes differ around the world. In some regions, such as North America and Europe, the air above the boundary layer must be much warmer than usual to form this CIN layer, whereas in other regions, especially the Middle East and central Africa, a CIN layer is common. Additionally, high CAPE occurrences that are over land (those in the Americas, Europe, Africa, and Southeast Asia) tend to lose their CIN layers before the time of maximum CAPE due to large diurnal cycles of sensible heating, whereas those that occur over coastal waters (in the Middle East, Northern Australia, South Asia, and the Mediterranean) usually retain substantial convective inhibition. Uniquely, CAPE in Southeast Australia often builds up due to cooling aloft rather than to boundary layer warming. These results show that one hoping to understand or predict CAPE patterns must understand a variety of mechanisms acting in different regions.

Comparison of High n-3 PUFA Levels and Cyclic Heat Stress Effects on Carcass Characteristics, Meat Quality, and Oxidative Stability of Breast Meat of Broilers Fed Low- and High-Antioxidant Diets.

This study investigated the individual and combined effects of a high dietary n-3 PUFA intake and cyclic heat stress (HS) on the carcass characteristics, meat quality, and oxidative stability of broiler breast meat and the potential of antioxidant supplementation (vitamins E, C, and selenium) to mitigate these effects. A total of 192 one-day-old male Ross 308 broilers were randomly assigned to 24 pens within two controlled environment chambers and fed with the following diets: a basal diet low in antioxidants according to NRC recommendations (NRC group), a basal diet according to Aviagen recommendations additionally supplemented with 200 IU/kg vitamin E, 250 mg/kg vitamin C, and 0.15 mg/kg selenium (HAOX group), and these two diets further supplemented with 5% linseed oil (NRC N-3 and HAOX N-3 groups). On day 22, the broilers were exposed to the following two environmental conditions: thermoneutral (TN, 21 °C) or cyclic HS (HS, 34 ± 1 °C, 7 h/d) in a 2 × 2 × 2 factorial design. A high intake of n-3 PUFAs significantly decreased growth performance, dressing percentage, and breast yield, while the incidence of pale, soft, and exudative (PSE) meat characteristics and malondialdehyde (MDA) levels increased. Cyclic HS reduced body weight (BW) and average daily feed intake (ADFI), but had limited effects on meat quality. No interactions between n-3 PUFAs and HS were observed for any measurements. High antioxidant supplementation increased breast yield, improved meat quality, and reduced oxidative stress, as evidenced by an enhanced antioxidant activity and lower MDA levels. In conclusion, n-3 PUFAs had a negative effect on both the carcass characteristics and meat quality of broilers, while HS primarily affected only carcass characteristics, with neither stressor having severe adverse effects. High levels of antioxidants could mitigate the negative effects of dietary- and heat-induced oxidative stress by enhancing the oxidative stability of broiler meat.