Simulation of copper-water nanofluid in a microchannel in slip flow regime using the lattice Boltzmann method with heat flux boundary condition

Laminar forced convection heat transfer of water–Cu nanofluids in a microchannel is studied using the double population Thermal Lattice Boltzmann method (TLBM). The entering flow is at a lower temperature compared to the microchannel walls. The middle section of the microchannel is heated with a constant and uniform heat flux, simulated by means of the counter slip thermal energy boundary condition. Simulations are performed for nanoparticle volume fractions equal to 0.00%, 0.02% and 0.04% and slip coefficient equal to 0.001, 0.01 and 0.1. Reynolds number is equal to 1, 10 and 50.The model predictions are found to be in good agreement with earlier studies. Streamlines, isotherms, longitudinal variations of Nusselt number and slip velocity as well as velocity and temperature profiles for different cross sections are presented. The results indicate that LBM can be used to simulate forced convection for the nanofluid micro flows. They show that the microchannel performs better heat transfers at higher values of the Reynolds number. For all values of the Reynolds considered in this study, the average Nusselt number increases slightly as the solid volume fraction increases and the slip coefficient increases. The rate of this increase is more significant at higher values of the Reynolds number

Effect of dietary cation-anion balance on milk production and blood mineral of Holstein cows during the last two months of pregnancy

This study was conducted to evaluate the effects of three diets with different cation-anion differences ((DCAD: mEq[(Na + K) − (Cl + S)]/100 g of dry matter)) in far-off and close-up period, on milk production and blood mineral of Holstein cows. Eighteen pregnant cows (220 - 225 d) were fed a base diet with three DCAD (+13 (control), 0, −13/100 g dry matter) for 60 ± 5 days. Control diet consisted of 170 g/kg corn silage, 396 g/kg alfalfa hay and 424 g/kg concentrate mix (dry matter basis). For decrease DCAD, two anionic salts such as ammonium chloride and ammonium sulphate were used. Production of milk and 3.5% fat corrected milk (FCM) were increased with decreasing DCAD. However, milk composition and yield of milk fat, protein and lactose were not affected by diets containing +13, 0 and −13 DCAD. In addition, prepartum dry matter intake, BCS change and body weight gains were similar for cows fed the three diets with different cation-anion differences. At calving, plasma calcium concentration was 6.55, 6.46 and 6.78 mg/dl for cows fed diets containing +13, 0 and −13 DCAD, respectively. Blood pH and concentration of K, Mg and Na were not affected by dietary cation-anion balance. Urinary pH of cows was affected by diets and was decreased linearly with decreasing DCAD. The mean urinary pH was 7.99, 6.81 and 6.11 for cows fed diets containing +13, 0 and −13 DCAD, respectively.Keywords: Metabolic disorders, pregnant cow, anionic saltsAfrican Journal of Biotechnology Vol. 9(36), pp. 5983-5988, 6 September, 201

Nature Inspires Estrus Synchronization in Murciano-Granadina Goats under Extremely Hot Climate

Despite the seasonal nature of reproduction in goats, creating a capacity that enables getting goats pregnant throughout the year is of economical importance in commercial settings. The objective was to compare natural and artificial (hormonal) methods of estrus synchronization on pregnancy rate of Murciano-Granadina goats under extremely hot climate of southern Iran. To synchronize estrus, experimental goats received one of three treatments. The first group (n = 123) was treated with CIDR (intravaginal progesterone release) on day-0 and which was later removed on day-19 plus eCG injection followed by introduction to bucks on day-21. The second group (n = 157) was treated with CIDR on day-0 and with eCG injection on day-17, then CIDR removed on day-19 followed by introduction to bucks on day-21. The third group (n = 257) did not receive any hormonal treatments and were only synchronized naturally via introduction to bucks (natural mating). Findings revealed that natural synchronization (male effect) resulted in significantly greater pregnancy rates compared to the second group (69 vs. 53%, P < 0.05). The first group tended to have greater pregnancy than did the first group (63 vs. 53%, P < 0.10). Improved reproductive performance of dairy goats under hot stressful climate signifies the economical importance and practicality of natural mating as an effective method of estrus synchronization in commercial goat production

Ruminal Dry Matter, Neutral Detergent Fibre and Acid Detergent Fiber Degradation Kinetics of Dominant Pasture Forages in Kurdestan Province of Iran

Neutral detergent fiber (NDF) is a major chemical component of forages and its degradability (dNDF) is an essential parameter in predicting their energetic value. Moreover, dNDF has been used in models to estimate the physical fill of fibrous feeds in the rumen and, therefore, the intake capacity of animals. As the available information on the nutritive value of pastoral forages is limited a study was undertaken to measure chemical composition and cell wall degradation kinetics of eight pasture forages in the rumen

Ground Wheat Grain for Midlactation Cows: Challenging a Common Wisdom

The objective was to determine the effects of ground wheat grain (GW) inclusion rate, grinding extent (GE), and their interaction on lactating cow performance. Eight midlactation cows in 3 × 4 m individual boxes were used in a 4 × 4 replicated Latin square design study with 4 21 d periods. GW was fed at either 10% or 20% of diet dry matter (DM), as either finer or coarser particles. DM intake increased and net energy for lactation (NEL) intake tended to increase when GW was fed at 10% instead of 20% of diet DM. Milk energy yield, milk solids content and yield, and urine pH were unaffected. Fecal pH tended to increase at 20% versus 10% GW. Total tract apparent NDF, but not DM, digestibility tended to be greater for coarsely than finely GW and tended to be greater at 10% versus 20% GW. GW at 10% versus 20% of diet DM decreased blood BHBA and increased blood concentrations of total proteins and albumin. Data provide novel evidence that both finely and coarsely ground WG can be safely fed up to 20% midlactation cows. Commercial accessibility and cost will determine feeding preference of wheat grain to dairy cows

Assessing IPv6 Through Web Access - A Measurement Study and Its Findings

Transitioning an infrastructure the size of the Internet is no small feat. We are in the midst of such a transition, \ie from IPv4 to IPv6. IPv6 was standardized 15~years ago, but until recently there were few incentives to adopt it. The allocation of the last large block of IPv4 addresses changed that, and migrating to an IPv6 Internet has become more urgent. This migration is, however, still rife with uncertainties and challenges. The goal of this paper is to provide insight into this transition, and possibly make it smoother. The focus is on the ``network,\u27\u27 and the paper reports on extensive measurements that compare and contrast IPv6 and IPv4. Two important hypotheses, denoted as H1 and H2, were identified and validated. H1 argues that the IPv6 and IPv4 data planes now perform by and large comparably. In contrast, H2 points to routing differences as the primary culprit behind occurrences of poorer IPv6 performance. In other words, promoting IPv6 and IPv4 peering parity is probably the single most effective step towards equal IPv6 and IPv4 performanc

Multi-port coordination: Unlocking flexibility and hydrogen opportunities in green energy networks

\ua9 2024Seaports are responsible for consuming a large amount of energy and producing a sizeable amount of environmental emissions. However, optimal coordination and cooperation present an opportunity to transform this challenge into an opportunity by enabling flexibility in their generation and load units. This paper introduces a coordination framework for exploiting flexibility across multiple ports. The proposed method fosters cooperation between ports in achieving lower environmental emissions while leveraging flexibility to increase their revenue. This platform allows ports to participate in providing flexibility for the energy grid through the introduction of a green port-to-grid concept while optimising their cooperation. Furthermore, the proximity to offshore wind farms is considered an opportunity for the ports to investigate their role in harnessing green hydrogen. The proposed method explores the hydrogen storage capability of ports as an opportunity for increasing the techno-economic benefits, particularly through coupling them with offshore wind farms. Compared to existing literature, the proposed method enjoys a comprehensive logistics-electric model for the ports, a novel coordination framework for multi-port flexibility, and the potentials of hydrogen storage for the ports. These unique features position this paper a valuable reference for research and industry by demonstrating realistic cooperation among ports in the energy network. The simulation results confirm the effectiveness of the proposed port flexibility coordination from both environmental and economic perspectives