Search

This research assesses the impact of major marine hydrodynamic factors, such as waves, currents, and sea levels on the changing processes of the seabed topography and the coastlines of the Namyit (Nam Yết) Island of Truong Sa (Spratly) Islands, based on a many continuous years-data set. The study uses MIKE model to calculate and simulate the impact of wave field and current field on the process of accretion and erosion that changes the topography of the seabed. The results show that when comparing between calculated wave height, speed of the currents, and sea level height and those observed on scene are 69.1%, 54.5%, and 95.4% respectively. These figures meet the requirement of Nash Sutcliffe Efficiency, in which calculated sea level shows highest reliability. The research results provide an overview of wave and currents regimes in Northeast and Southwest monsoon seasons, and the characteristics of the current seabed topography around Namyit Island. The changing of seabed around Namyit Island includes diversified accretion and erosion. In the area from the depth of 10 m to the Island’ coastlines, the accretion dominant, with sediment thickness of up to 2.0 m. At 200 m West and East of the island, there have erosion areas, with sediment thickness reduces to 1.0 m. The changing of natural seabed topography of the researched area is mainly impacted by the process of accretion and erosion of sediment due to hydrodynamic regimes (waves, currents, and sea levels fluctuations) and the development and decline of seabed coral system. The research results are the scientific basis for planning, and proposing the construction around the island, planning for navigation channels dredging, and providing information for naval training, exercises, and operations around offshore islands.

We present a numerical study on a 2D array of plasmonic structures covered by a subwavelength film. We explain the origin of surface lattice resonances (SLRs) using the coupled dipole approximation and show that the diffraction-assisted plasmonic resonances and formation of bound states in the continuum (BICs) can be controlled by altering the optical environment. Our study shows that when the refractive index contrast Δn n > 0.3) not only sustains plasmonic-induced resonances but also forms both symmetry-protected and accidental BICs. The results can aid the streamlined design of plasmonic lattices in studies on light–matter interactions and applications in biosensors and optoelectronic devices.

Owing to their high oscillator strength, binding energy, and low-cost fabrication, two-dimensional halide perovskites have recently gained attention as excellent materials for generating exciton-polaritons at room temperature. Unlike traditional materials used for polaritons, such as ZnO, GaAs, and GaN, halide perovskites exhibit great compatibility with matured CMOS technologies. However, no studies have reported perovskite-based polaritons on silicon platforms. Here, we numerically demonstrate the possibility of a polariton when a Si nanodisk array couples with a thin film of phenethylammonium lead iodide perovskite. An asymmetric lattice of thin Si nanodisks is used to generate surface lattice resonances from the coupling between the disk's electrical resonator and the lattice's diffracted waves. Polaritonic modes with high Rabi splitting values can be easily achieved for a large range of parameters. This Rabi splitting can be engineered by varying the ratio of electromagnetic energy confined within the Si disk and perovskite thin film. This study provides insight into nanophotonic structure design for CMOS-based optoelectronics, sensors, and polaritonic devices.

A total of 140 growing pigs [Duroc × (Yorkshire × Landrace)] with an average body weight of 24.10 ± 1.66 kg were used in a 6 wk trial to determine the effect of dietary protease supplementation to ...

A total of 105 finishing pigs [(Yorkshire × Landrace) × Duroc] with an initial body weight of 51.0 ± 3.33 kg were used in a 10 wk trial to evaluate the effect of a protected blend of organic acids ...

International audience; In many situations of practical or/and theoretical interest, the assumption that the interfaces between constituent phases of a composite are smooth is no longer appropriate, and the consideration of rough interfaces at microscopic scale is necessary. However, in micromechanics, when the interfaces between the constituent phases of composites become rough, all classical well-known micromechanical schemes resorting to Eshelby's formalism cannot be applicable and the problem of determining the effective properties of composites become largely open. The present work aims to determine the effective thermal conductivity of a composite in which the interfaces between its constituent phases are perfectly bonded but oscillate quickly around a curved surface and along two directions. To achieve this objective, a two-scale homogenization method is proposed. In the first-scale homogenization, or microscopic-to-mesoscopic upscaling, the interfacial zone in which the interface oscillates is homogenized as an equivalent interphase by applying an asymptotic analysis. The thermal properties of the equivalent interphase can generally be determined by using a numerical approach based on the fast Fourier transform (FFT) method. In particular case where the equivalent interphase is very thin, this interphase is then replaced with a general imperfect interface situated at its middle surface. By applying the equivalent inclusion method, every inclusion with imperfect interface is further substituted by an equivalent inclusion with perfect interface. In the second scale homogenization, or mesoscopic-to-macroscopic upscaling, due to the fact that the interfaces are perfect, the effective thermal conductivity can be analytically obtained by using some well-known classical micromechanical schemes. To illustrate the two-scale homogenization method proposed in this work, the case of a layered

Simple Summary Many countries have enforced a ban on the use of all antibiotics in animal feed as growth promoters due to public health concerns about the emergence of antimicrobial resistance. There are a variety of candidates for the replacement of antibiotic growth promoters like probiotic, prebiotics, herbs, or essential oil. Organic acids have been suggested as alternatives to replace antibiotics in the diets of animals. It is reported that the lower the pKa of the OAs, the greater its effect on the reduction of stomach pH and the lower its antimicrobial effect in the more distal portions during its transit through the GIT which eventually will have better effect on animal’s health as well as their performance. Herein, we focus on the use of organic acids’ mixture as feed additives in the diet of swine in term of their immune system, gut health, nutrient digestibility, and growth performance as well as gas emission. Abstract Due to the increasing safety concerns about the risk of spreading antibiotic resistance in the environment, and the presence of chemical residues in animal products, using organic acids (OAs) to replace antibiotic in the diet of farm animals has increased considerably in recent years. It has been suggested that OAs could attribute to diverse elements such as antimicrobial activity, decreasing the pH of digesta particularly in the gastrointestinal tract (GIT), slowing feed transit in the GIT to maximize feed digestion and nutrient absorption, inducing enzyme secretion and activity in the small intestine, and providing nutrients to intestinal tissue. It has been reported that OAs mixture might be more effective than individual OAs due to the synergistic effects of different pKa values and have a broad-spectrum activity. In conclusion, this review showed that an OA mixture, which can improve nutrient digestibility and growth performance, modulate intestinal bacterial populations and improve gut health, as well as decreasing gas emission, can be used as alternative to antibiotic growth promoters. However, the results of OA mixtures are not always consistent, and the response to dietary OAs could be affected by the type of OAs, dosage, feed formula, and the age of animals. In this review, we will give an overview of the current use of OAs mixture in swine feed.

We investigated the effects of a blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) supplementation in 800 1-d-old male Ross 308 broiler chickens (42 &plusmn, 0.90 g) in a 7-week study. Broiler chicks were randomly allocated into one of the five dietary treatments (16 birds per pen with 10 pens per treatment). Dietary treatments consisted of corn-soybean meal based basal diet and the basal diet supplemented with blend of OAs and MCFAs at 0.25, 0.5, 0.75 g, and 1 g per kg of feed. In the current study, during the whole experimental period, the inclusion of the blend of OAs and MCFAs in the basal diet linearly improved (p &lt, 0.05) body weight gain (BWG), feed conversion ratio (FCR), and dry matter digestibility. The increasing inclusion of the blend of OA and MCFA levels in the diets linearly decreased (p = 0.002) feed intake during d 1 to 7. Broilers fed diets containing different levels of the blend of OAs and MCFAs showed a linear increase (p = 0.006) in Lactobacillus concentrations and decrease (p = 0.014) in ammonia (NH3) at the end of the experiment. However, the blend of OAs and MCFAs did not affect carcass quality, E. coli, and Salmonella counts, as well as hydrogen sulfide and total mercaptans gas emission (p &gt, 0.05). In conclusion, the blend of OA and MCFA supplementation positively influenced growth performance, DM digestibility, excreta Lactobacillus counts, as well as NH3 gas emission in broiler chickens.

An experiment was conducted to assess effects of Enterococcus faecium and a blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) in finishing pigs. A total of 120 pigs [Duroc × (Yorkshire × Landrace); 51.04 ± 1.82 kg] were randomly assigned to five dietary treatments: CON, basal diet; BOM1, CON + 500 mg kg−1 blend of OAs and MCFAs; BOM2, CON + 1000 mg kg−1 blend of OAs and MCFAs; EBOM1, BOM1 + 20 mg kg−1 E. faecium; EBOM2, BOM2 + 20 mg kg−1 E. faecium. Pigs fed EBOM1 and EBOM2 diets had higher average daily gain and average daily feed intake (during days 36–70 and days 1–70) and greater digestibility of dry matter (days 35 and 70) compared with those fed BOM1 and BOM2 diets (P 0.05). In conclusion, supplementation with the combination of E. faecium and a blend of OAs and MCFAs was more effective in improving growth performance and nutrient digestibility than supplementation with blend of OAs and MCFAs alone in finishing pigs.

A total of 180 crossbred pigs [(Landrace × Yorkshire) × Duroc] with an average body weight of 22.61 ± 1.23 kg were used in an 18 wk study to determine the effect of protease and bromelain in low-protein diets in grower–finisher pigs. Dietary treatments included: T1, basal diet treatment; T2, low-protein treatment; T3 (T2 + 0.2 g kg−1 protease); and T4 (T2 + 0.3 g kg−1 bromelain). Pigs fed protease- and bromelain-supplemented diets increased average daily gain and gain to feed ratio at week 18, dry matter and nitrogen digestibility at week 6, as well as energy digestibility at week 12, compared with low-protein diet (P 3) and hydrogen sulfide (H2S) emission was observed in pigs fed the dietary protease and bromelain supplementation at the 6th wk (P 3 and H2S in growing–finishing pigs.

A total of 480 one-day-old male Ross 308 broilers with an average initial body weight (BW) of 42 ± 1 g was randomly divided into four treatments (8 replicates/treatment, 15 birds/replicate) by their BW to evaluate the influence of a cocktail of protease and xylanase in different energy density of corn- and soybean-meal-based diet on broilers. This experiment lasted for 35 d and there were two phases; starter (1–18 d) and finisher (19–35 d). The experiment was a 2 × 2 factorial arrangement with two levels of metabolizable energy and the cocktail enzyme with 200 mg of protease kg−1 diet and 100 FXU xylanase kg−1 diet. Both high-nutrient density and cocktail enzyme supplementation increased (P 3) and hydrogen sulphide (H2S) emission. In conclusion, dietary supplementation of the cocktail enzyme component improved BWG, N retention, and reduced excreta noxious gas emission in broilers.

This study aimed to evaluate the effects of dietary supplementation of lysolecithin emulsifier on growth performance, nutrient digestibility, and blood lipid profiles in growing broiler chickens. In total, 1,020 1-day-old male Ross 308 broiler chickens with an average initial live weight of 43±1.2 g were randomly allotted to five dietary treatments for a 35 d experiment. The treatments included: (1) NC, negative control (metabolizable energy (ME)=3,100 kcal/kg for phase 1 and phase 2), (2) PC, positive control (ME=3,200 kcal/kg), (3) T1, NC+0.03% lysolecithin, (4) T2, NC+0.06% lysolecithin, and (5) T3, NC+0.09% lysolecithin. During days 1-35, the feed conversion ratios (FCR) of broiler chickens fed with T2 and T3 diets were lower than those of broiler chickens fed with NC diet (P

This study was conducted to evaluate the effect of different omega-6: omega-3 fatty acid (FA) ratios in a corn&ndash, soybean meal-based diet in growing pigs. A total of 140 [Duroc &times, (Landrace &times, Yorkshire)] growing pigs with an average body weight (BW) of 24.75 &plusmn, 1.43 kg were used in a 6-week trial. Pigs were allocated randomly into one of four treatments according to sex and BW (seven replications with five pigs per pen). The treatment groups consisted of 4 diets with omega-6:omega-3 FA ratios of 17:1, 15:1, 10:1, and 5:1. In the current study, the energy digestibility, BW, and average daily gain (ADG) increased (p &lt, 0.05) in pigs provided with the 5:1 diet compared to pigs fed the 17:1 diet in the sixth week. The low-density lipoprotein (LDL) concentrations of blood were lower (p &lt, 0.05) in pigs fed the 5:1 diet compared to the 17:1 and 15:1 diet. However, the fecal microflora and fecal gas emissions were unaffected (p &gt, 0.05) by the different omega-6: omega-3 FA ratios in diets. In conclusion, reducing omega-6: omega-3 ratio by increasing omega-3 in diet improved BW, ADG, and gross energy digestibility, and reduced the LDL concentrations of blood in growing pigs.

This study was conducted to determine the effect of crumbled diet on growth performance, market day age, and meat quality of growing-finishing pigs. A total of 120 crossbred pigs [(Landrace × Yorks...

This study was conducted to evaluate the effect of Enterococcus faecium (EF) and endo-1,4-β-xylanase (XY) in finishing pigs. The pigs were randomly divided into four treatments with eight replicati...

A total of 26 (Landrace × Yorkshire) sows were randomly allotted to two experimental dietary treatments: 1) basal diet (CON); 2) CON plus 0.28% sow pack (SP) to determine the effect of Bacillus subtilis, essential oil, chromium and glucose as sow pack supplementation on sows and piglets. During the overall study, sows fed the SP diet increased body weight of sow after weanling and farrowing, sow back-fat thickness on d 110 , average daily gain of piglets, the level of immunoglobulin-G (IgG) and insulin on d 14 lactating and after weanling and decreased body weight loss, the level of cortisol and glucose on d 14 lactating as well as the level of cortisol after weanling 3 d (P less than 0.05). In conclusion, the results indicated that supplementation of sow pack diet increased performance of sows and piglets, IgG, insulin of blood and decreased the cortisol and glucose in the blood profiles of sows.

This experiment was conducted to evaluate the effect of extracted rice bran supplementation in the diet on production performance, feed intake, egg quality, and excreta microflora in laying hens. A...

A total of 160 crossbred weanling pigs [(Landrace × Yorkshire) × Duroc, 28 days old] with an initial bodyweight of 8.01 ± 0.74 kg were used in a 42-day trial (Phase 1: Days 1–14, Phase 2: Days 14–42). The experiment was conducted to evaluate the effects of the inclusion of fermented oats (FO) to a corn and soybean meal-based diet on the performance of weanling pigs fed with high nutrient-density (HD) and low nutrient-density (LD) diets. Pigs were randomly distributed into one of four dietary treatments in a 2 × 2 factorial arrangement. Two levels of nutrient density [LD = 3323 (Phase 1: 1–14 days) and 3269 kcal/kg (Phase 2: 14–42 days); HD = 3446 (Phase 1: 1–14 days) and 3325 kcal/kg (Phase 2: 14–42 days), the differences in dietary energy were based on differences in the content of fish meal, animal fat, corn and FO [0%, 5% (Phase 1) or 2.5% (Phase 2)] were used according to the bodyweight and sex of pigs [8 replicate pens per treatment with 5 pigs in a pen (3 gilts and 2 barrows)]. During the overall trial period (Days 1–42), the average daily gain and gain:feed ratio of pigs fed HD and FO diets were significantly higher (P ≤ 0.05) than those of pigs fed with LD and non-fermented oats diets respectively. On Day 14, the apparent total tract digestibility of dry matter and nitrogen of the HD groups were significantly greater (P ≤ 0.05) than those of the LD groups. The apparent total tract digestibility of energy of the FO groups was significantly greater (P ≤ 0.05) than that of the non-fermented oats diet groups during the whole experimental period. Pigs fed with FO showed higher (P ≤ 0.05) ileal Lactobacillus and lower (P ≤ 0.05) Escherichia coli counts compared with those fed with the non-fermented oats diet. In conclusion, administration of FO to a LD diet demonstrated beneficial effects on the growth performance, nutrient digestibility and ileal microorganisms balance of weanling pigs.