Thermal Transport in Radiative Nanofluids by Considering the Influence of Convective Heat Condition

The analysis of nanofluid dynamics in a bounded domain attained much attention of the researchers, engineers, and industrialists. These fluids became much popular in the researcher’s community due to their broad uses regarding the heat transfer in various industries and fluid flowing in engine and in aerodynamics as well. Therefore, the analysis of Cu-kerosene oil and Cu-water is organized between two Riga plates with the novel effects of thermal radiations and surface convection. The problem reduced in the form of dimensionless system and then solved by employing variational iteration and variation of parameter methods. For the sake of validity, the results checked with numerical scheme and found to be excellent. Further, it is examined that the nanofluids move slowly by strengthen Cu fraction factor. The temperature of Cu-kerosene oil and Cu-water significantly rises due to inducing thermal radiations and surface convection. The behaviour of shear stresses is in reverse proportion with the primitive parameters, and local Nusselt number increases due to varying thermal radiations, Biot number, and fraction factor, respectively.

Soret–Dufour impact on a three-dimensional Casson nanofluid flow with dust particles and variable characteristics in a permeable media

In this study, the effects of variable characteristics are analyzed on a three-dimensional (3D) dusty Casson nanofluid flow past a deformable bidirectional surface amalgamated with chemical reaction and Arrhenius activation energy. The surface is deformable in the direction of the x-axis and y-axis. The motion of the flow is induced due to the deformation of the surface. The impression of Soret and Dufour's effects boost the transmission of heat and mass. The flow is analyzed numerically with the combined impacts of thermal radiation, momentum slip, and convective heat condition. A numerical solution for the system of the differential equations is attained by employing the bvp4c function in MATLAB. The dimensionless parameters are graphically illustrated and discussed for the involved profiles. It is perceived that on escalating the Casson fluid and porosity parameters, the velocity field declines for fluid-particle suspension. Also, for augmented activation energy and Soret number, the concentration field enhances. An opposite behavior is noticed in the thermal field for fluctuation in fluid-particle interaction parameters for fluid and dust phase. Drag force coefficient increases on escalating porosity parameter and Hartmann number. On amplifying the radiation parameter heat and mass flux augments. A comparative analysis of the present investigation with an already published work is also added to substantiate the envisioned problem.

Realization of electromagnetic shielding performance for polyimide-matrix composite by self-metallization

Electromagnetic shielding performance has been achieved for a polyimide (PI)-matrix composite by the strategy of self-metallization of its thermosetting PI matrix. Self-metallization of the thermosetting PI was realized by silver ion/poly(amic acid) (PAA) precursor ion exchange and thermal reduction. The factors influencing the self-metallization were investigated. The electrical conductivity and integrity for the surface of the PI were achieved by optimization of ion exchange/thermal reduction parameters. The fabricated PI-matrix composite exhibits a maximum electromagnetic interference shielding effectiveness value of 81 dB. Importantly, the electromagnetic shielding performance can be maintained even after heat condition of 300°C. Meanwhile, the surface-metallized PI composite exhibits mechanical property equivalent to the pristine composite, and an Ag/matrix interfacial strength higher than 19.6 MPa. Besides, self-metallization mechanism of the thermosetting PI was investigated.

Exogenous Methyl Jasmonate Improves Heat Tolerance of Perennial Ryegrass Through Alteration of Osmotic Adjustment, Antioxidant Defense, and Expression of Jasmonic Acid-Responsive Genes

Perennial ryegrass (Lolium perenne L.) is an important cool-season grass species that is widely cultivated in temperate regions worldwide but usually sensitive to heat stress. Jasmonates (JAs) may have a positive effect on plant tolerance under heat stress. In this study, results showed that exogenous methyl jasmonic acid (MeJA) could significantly improve heat tolerance of perennial ryegrass through alteration of osmotic adjustment, antioxidant defense, and the expression of JA-responsive genes. MeJA-induced heat tolerance was involved in the maintenance of better relative water content (RWC), the decline of chlorophyll (Chl) loss for photosynthetic maintenance, as well as maintained lower electrolyte leakage (EL) and malondialdehyde (MDA) content under heat condition, so as to avoid further damage to plants. Besides, results also indicated that exogenous MeJA treatment could increase the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), thus enhancing the scavenging ability of reactive oxygen species, alleviating the oxidative damage caused by heat stress. Heat stress and exogenous MeJA upregulated transcript levels of related genes (LpLOX2, LpAOC, LpOPR3, and LpJMT) in JA biosynthetic pathway, which also could enhance the accumulation of JA and MeJA content. Furthermore, some NAC transcription factors and heat shock proteins may play a positive role in enhancing resistance of perennial ryegrass with heat stress.

Penurunan Durasi Berbaring Harian Sapi Berahi, sebagai Peluang untuk Dijadikan Teknologi Otomatisasi Peringatan Dini Sapi Berahi

ABSTRAK. Saat ini sudah tersedia berbagai produk teknologi monitoring kesehatan ternak berdasarkan analisis tingkah laku ternak. Namun belum ada teknologi monitoring berdasarkan tingkah laku yang cocok untuk pemeliharaan intensif seperti di Indonesia. Penelitian ini bertujuan untuk mendapatkan dasar teknologi monitoring sapi berahi berdasarkan perubahan total durasi berbaring harian antara sapi berahi dengan non berahi. Sebanyak 18 ekor sapi betina Peranakan Ongole (PO) sehat reproduksi ditempatkan pada kandang individu yang terpantau kamera selama 24 jam. Pengambilan data foto posisi berbaring atau berdiri sapi dilakukan tiap 2 menit. Dilakukan penjumlahan durasi total berdiri dan berbaring harian selama satu siklus berahi. Penentuan kondisi berahi menggunakan metode visual dan menggunakan heat detector “Brunstmessgerat”. Uji T test berpasangan dilakukan untuk membandingkan rata-rata berbaring harian sapi non berahi dengan durasi harian sapi berahi. Hasil penelitian menunjukkan bahwa lama siklus berahi adalah sebesar 20,3 ± 1,5 hari yang mengindikasikan sapi sehat secara reproduksi dan mendapatkan ketercukupan nutrisi pakan. Data total durasi berbaring harian yang didapatkan dari hasil tangkapan foto kamera menunjukkan sebaran data yang terdistribusi normal dan terdapat perbedaan yang nyata antara total durasi berbaring harian sapi berahi 49,83% dengan rata-rata total durasi berbaring harian sapi non berahi 53,60%. Hasil ini membuka peluang untuk dikembangkan menjadi teknologi monitoring sapi berahi berdasarkan perbedaan tingkah laku berbaring sapi. (Decreasing of the total daily lying behavior on oestrus cow, as an opportunity to become an automatic warning system for oestrus cows) ABSTRACT. Today, various livestock health monitoring technology products based on the analysis of livestock behavior are available. However, there is no behavior-based monitoring technology suitable for intensive maintenance such as in Indonesia. This study aims is to obtain the basic monitoring technology for heat cows based on changes of the total daily lying behavior duration between oestrus and non oestrus cows. A total of 18 healthy PO cows were placed in individual pan which were monitored by the camera in 24 hours a day. Collecting photo data from lying or standing position of the cow was done every 2 minutes. The total duration of daily standing and lying behavior for one oestrus cycle was done. The determination of the heat condition used a visual method and a heat detector manufactured by Brunstmessgerat. Paired T-test was conducted to compare the average daily lying behavior of oestrus and non oestrus cows. The results showed that the oestrus cycle length was 20,3 ± 1,5 days, which indicated that the cows were reproductively healthy and had adequate feed nutrition. The total daily lying behavior duration data obtained from the camera photo captures showed that the distribution of data is normally distributed and there is a significant difference between the total daily lying behavior duration of oestrus 49,83% and non oestrus 53,60%. This result opens the opportunity to be developed into a monitoring technology for oestrus cows based on differences in the lying behavior.

Static and dynamic failure mechanisms of circular granite under the condition of water-heat cycles

Based on the engineering environment where rocks surrounding wellbores in energy storage areas are influenced by high temperature, cool and hot water, thermal stress etc. in the exploitation of hydrothermally geothermal energy, the experimental study on mechanical properties of ring granite under the static and dynamic loads in the water-heat condition was performed. The experimental results showed that when the ring granite was influenced by the inner diameters, heating temperatures, curing temperatures and heat recovery cycle times, the impact load-strain curves were nonlinear. However, the concave stages, platform stages and cliff-like drop stages appeared in the load-strain curves under the static loads. The radical peak loads decreased exponentially with the growth of the damage factors and the dynamic peak loads were far greater than the static peak loads. By analyzing the damage cracks and broken fragments, it was found that under the static and dynamic radical loads, the cracks generated in the ring specimens were tensile cracks and the failure mode was tensile failure. However, the dynamic failure was more aggressive than the static failure. Then, the apparent deformation modulus was defined to describe the deformation characteristics of ring granite before the radical peak loads. And it is found that the variation law of dynamic apparent deformation modulus is more dispersed than the changes of static apparent deformation modulus. Finally, based on the deformation and failure characteristics of ring granite obtained from the tests, the static and dynamic failure criteria considering whether the cracks along the loading direction were generated in the inner ring wall were deduced and verified by the corresponding tests.

Impact of climate change on poultry production: A review Impact du changement climatique sur la production avicole: un bilan

One of the major challenges the world is facing currently is the issue of climate change, which is majorly caused by the emission of greenhouse gas that results in warming of the atmosphere, thus poses a threat to agriculture, socio-economic development and feed sustainability. An aspect of agriculture majorly affected by climate change is poultry production. The effect of climate change can be felt by poultry birds due to its range in thermal condition that affects the animal's physiological and behavioural activities. Production in Poultry birds is mostly at its peak under a tolerable heat condition. An understanding of how to control environmental conditions is very crucial to a successful poultry production and welfare. Climate change influences the following aspect of poultry production; chicken embryonic development, growth and production efficiency, egg production and egg quality, meat quality and disease. L'un des principaux défis auxquels le monde est actuellement confronté est le problème du changement climatique, qui est principalement causé par l'émission de gaz à effet de serre qui entraîne un réchauffement de l'atmosphère, qui constitue donc une menace pour l'agriculture, le développement socio-économique et la durabilité des aliments. La production de volaille est l'un des aspects de l'agriculture les plus touchés par le changement climatique. L'effet du changement climatique peut être ressenti par les volailles en raison de sa plage de conditions thermiques qui affecte les activités physiologiques et comportementales de l'animal. La production des volailles est surtout à son apogée dans des conditions de chaleur tolérables. Une compréhension de la façon de contrôler les conditions environnementales est très cruciale pour une production et un bien-être avicole réussis. Le changement climatique influence l'aspect suivant de la production de volaille; développement embryonnaire de poulet, croissance et efficacité de la production, production et qualité des œufs, qualité de la viande et maladies.

Alternative Polyadenylation in response to temperature stress contributes to gene regulation in Populus trichocarpa

Background Genome-wide change of polyadenylation (polyA) sites (also known as alternative polyadenylation, APA) is emerging as an important strategy of gene regulation in response to stress in plants. But little is known in woody perennials that are persistently dealing with multiple abiotic stresses. Results Here, we performed a genome-wide profiling of polyadenylation sites under heat and cold treatments in Populus trichocarpa. Through a comprehensive analysis of polyA tail sequences, we identified 25,919 polyA-site clusters (PACs), and revealed 3429 and 3139 genes shifted polyA sites under heat and cold stresses respectively. We found that a small proportion of genes possessed APA that affected the open reading frames; and some shifts were commonly identified. Functional analysis of genes displaying shifted polyA tails suggested that pathways related to RNA metabolism were linked to regulate the APA events under both heat and cold stresses. Interestingly, we found that the heat stress induced a significantly more antisense PACs comparing to cold and control conditions. Furthermore, we showed that a unique cis-element (AAAAAA) was predominately enriched downstream of PACs in P. trichocarpa genes; and this sequence signal was only absent in shifted PACs under the heat condition, indicating a distinct APA mechanism responsive to heat tolerance. Conclusions This work provides a comprehensive picture of global polyadenylation patterns in response to temperatures stresses in trees. We show that the frequent change of polyA tail is a potential mechanism of gene regulation responsive to stress, which are associated with distinctive sequence signatures.