Flake Density Research Articles

Influence of flake density and starch retrogradation on in vitro gas production kinetics, digestibility, and ruminal fermentation characteristics of steam-flaked corn.

Previous research has demonstrated that decreasing starch availability of steam-flaked corn by increasing flake density or increasing the degree of starch retrogradation influences in vitro gas production kinetics. However, it is unclear if increasing flake density or the degree of starch retrogradation influences end-products of in vitro ruminal fermentation (methane, volatile fatty acids, ammonia). The objective of this experiment was to evaluate the effects of increasing flake density and the degree of starch retrogradation on in vitro gas production kinetics, digestibility, and ruminal fermentation characteristics of steam-flaked corn. Three ruminally-cannulated steers were fed a high-concentrate diet and sampled for ruminal digesta for an in vitro fermentation experiment with a 5×2 factorial arrangement of treatments. Steam-flaked corn was produced to flake densities of 257, 296, 335, 373, and 412g/L by adjusting the rolls of a steam-flaker. Samples were stored for 3 d at either 23°C to produce fresh steam-flaked corn or at 55°C in heat-sealed foil bags to produce retrograded steam-flaked corn. In vitro fermentation vessels were incubated for 24h and then assessed for fermentation parameters including dry matter digestibility, volatile fatty acid concentrations, and total gas and methane production. Increasing the degree of starch retrogradation decreased (P < 0.01) the rate of gas production across all flake densities of steam-flaked corn but did not decrease the extent of gas production. In vitro methane production, dry matter digestibility, and microbial biomass concentration were not influenced by increasing flake density or starch retrogradation. Increasing the degree of starch retrogradation decreased (P = 0.03) the molar propionate proportion and increased (P < 0.06) the molar proportions of butyrate, isobutyrate, and isovalerate and the acetate:propionate ratio. Enzymatic starch availability of steam-flaked corn was positively correlated with mean propionate proportion (r2 = 0.93) and negatively correlated with the mean butyrate proportion (r2 = 0.89). Results from the current study demonstrate that increasing the degree of starch retrogradation of steam-flaked corn decreased the rate of in vitro gas production and altered volatile fatty acid profiles in the ruminal fermentation media.

A New Purpose to Old Arsenal: Exploring the Safety and Efficacy of a New Regimen Comprising a Combination of Chlorhexidine Gluconate and Cetrimide for Seborrheic Dermatitis Treatment in a Randomized Placebo-Controlled Clinical Trial.

Seborrheic dermatitis is a common scalp condition affecting the quality of life of individuals across all age groups. The uninhibited proliferation of Malassezia spp. and enhanced sebaceous gland activity often leads to scalp flaking, mild erythema, and itching, thereby worsening the situation. Here, we aimed to study the efficacy of an antiseptic liquid as a pre-shampoo rinse followed by a non-anti-dandruff shampoo as a dandruff care strategy. Methods: The anti-dandruff efficacy of a chlorhexidine-cetrimide-based antiseptic liquid (ASL) as a pre-shampoo scalp rinse, followed by a regular non-anti-dandruff shampoo, was compared with a commercialZinc pyrithione (ZnPTO) based anti-dandruff shampoo following a half-head paired treatment design in a randomized, placebo-controlled, double-blind trial. The study was conducted on 50 healthy human adults of both genderswith moderate to severe dandruff. During the 12 weeks of this study, the product's safety and efficacy were evaluated based on the dermatologist's visual assessment, the subjects' self-assessment, the loose flake density score, and hair fall. ASL as a pre-shampoo scalp rinse demonstrated significant reduction (p<0.001 for n=47) in dandruff and itching after the treatment and the regression phase, performing at par with a marketed anti-dandruff shampoo. Moreover, ASL was established to be safe, non-irritant, and well-tolerated. No product-related adverse event, discomfort, or irritation symptoms were recorded, having any impact on hair sensory properties. This study demonstrates that a regimen of a chlorhexidine+cetrimide antiseptic liquid for scalp treatment followed by rinse with a regular shampoo can prove as effective as a ZnPTO-based anti-dandruff shampoo in reducing dandruff symptoms for individuals with moderate dandruff.

High Surface Area MoS2 and WS2 As Active HER Catalysts

The ever-increasing demand for clean energy necessitates a widespread adoption of clean energy carriers, namely green hydrogen. However, its production via electrolysis remains expensive. To achieve the needed drop in production cost, efficient catalyst materials are sought after to overcome the energy barrier of water splitting. Transition metal dichalcogenides (TMDCs) such as tungsten and molybdenum disulfide (WS2, MoS2) have been identified as promising catalysts because of their remarkably low Gibbs free energy for hydrogen adsorption.[1] The main challenge for these materials is the precise fabrication of continuous (mono)layers to achieve the desired functional properties.[2] Bottom-up material fabrication approaches like the vapor phase methods CVD and ALD offer several advantages. The use of chemical reactions of gas phase species allows precise thickness control, high quality films and allow large areas to be coated.This study focused on the fabrication of WS2 and MoS2 layers via metal organic chemical vapor deposition (MOCVD) and subsequent investigation of the properties of the resulting films in relation to the applied process conditions. Depositions were performed on FTO substrates and their thickness dependent capability to catalyze the electrochemical hydrogen evolution reaction (HER) were investigated in detail.For WS2 the selective growth of the semiconducting hexagonal phase with the targeted stoichiometry at a deposition temperature of 600°C was achieved (Fig 1 a). Similarly, in the case of MoS2, the hexagonal phase could be selectively deposited from 400 °C onwards and with pronounced crystallinity at 600°C (Fig. 1 b) which also showed the best stochiometric match and highest purity. The thin film characterization was further supported by Raman spectroscopy which serves as probe to verify the formed phase and layer number for 2D-materials. UV-VIS spectroscopy was employed to assess the semiconducting behavior allowing for band gap determination via the Tauc plot. Morphology and surface topography, especially interesting in the realm of HER catalysis, were assessed by SEM and HR-TEM showing the typical flakelike features known for these materials in their hexagonal phase (Fig 1 c). Electrochemical LSV experiments of WS2 in H2SO4 showed thickness dependence of the overpotentials which correlates with the flake density and the availability of vertical edge sites most active for HER (Fig 1 d). Similar studies for MoS2 are ongoing. These results are especially noteworthy as previous studies on WS2 deposited onto FTO have reported notably higher overpotentials.[3,4] This study demonstrates the potential of large area and high surface area TMDCs as effective HER electrocatalysts.[1] S. H. Noh, J. Hwang, J. Kang, M. H. Seo, D. Choi, B. Han, J. Mater. Chem. A 2018, 6, 20005–20014.[2] K. S. Novoselov, D. Jiang, A. K. Geim, et al. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 10451–10453.[3] J.-L. Wree, J.-P. Glauber, A. Devi, et al. J. Mater. Chem. C 2021, 9, 10254–10265.[4] J.-L. Wree, E. Ciftyurek, A. Devi, et al. Dalton Trans. 2020, 49, 13462–13474. Figure 1

Toward an understanding of the mechanism of mixed-salt-mediated CVD growth of MoSe2

The use of liquid precursors in chemical vapor deposition (CVD) techniques is advantageous for growing large-area, uniform two-dimensional (2D) transition-metal dichalcogenides (TMDs) compared to conventional methods using solid precursors. While various liquid precursors have been explored, recent studies highlight the use of mixed-salt precursors for growing uniform and wafer-scale TMDs. In this study, we propose a growth mechanism and present our findings on the epitaxial growth of MoSe2 domains as a function of annealing/growth time and H2 flow rate using Na2MoO4 and Na2SeO3 mixed-salt precursors. We confirm that the increase in the annealing time enhances the distribution of spin-coated precursors, leading to a rise in flake number density. On the other hand, prolonged growth time results in better-aligned MoSe2 flakes along the c-sapphire substrate step-edges. A significant finding is the dynamic diffusion of dendritic structures within large domains over the growth period, owing to the constant dissolution and recrystallization in the presence of residual liquid alloys. An increase in the H2 flow during CVD growth yields small, triangular domains aligned with the step edges, a result of the efficient reduction of precursor alloys and subsequent selenization. Our results provide an insight on achieving uniform and aligned morphology in CVD growth of 2D TMDs using liquid-phase precursors, a crucial step toward large-area fabrication.

Wafer-scale MOCVD grown WS2 with normally off transistor behavior and its general application on different amorphous substrates

In this study, we investigated various approaches to manipulate the flake density, size, and thickness of two-dimensional transition metal dichalcogenides by independently tuning the precursors and process conditions of the metal–organic chemical vapor deposition system. Normally off device characteristics were realized for both the as-grown and transferred cases. Furthermore, we demonstrated the versatility of our growth method by applying it to several commonly used gate dielectric materials, such as SiO2, SiNx, and AlOx.

Practical parameters for assessing starch digestion and feeding value of steam-flaked corn in finishing diets for feedlot cattle

ABSTRACT Six Holstein steers (153 kg ± 11) with cannulas in the rumen and proximal duodenum were used in a 6 × 6 Latin square design experiment to compare flake density (FD, kg/L), flake thickness (FT, mm), amyloglucosidase reactivity (AGR, % DM) and faecal starch (FS, % DM) as predictors of ruminal (RSD, %) and total tract (TSD, %) starch digestion. Dietary treatments consisted of a finishing diet containing 77% corn. The six corn processing treatments consisted of dry-rolled corn (DRC) with a density of 0.54 kg/L, and steam-flaked corn (SFC) processed to obtain densities of 0.46, 0.41, 0.36, 0.31 and 0.26 kg/L. Compared with DRC, steam flaking enhanced postruminal (34.2%, P < 0.01) and TSD (7.8%, P < 0.01). Measures of FS were the best single predictor of both ruminal (r 2 = 0.97) and TSD (r 2 = 0.98). Whereas AGR was a good predictor of RSD (r 2 = 0.94), it was less effective than FS for estimation of TSD (r 2 = 0.91). We conclude that compared with dry rolling, stream flaking markedly enhances the feeding value of corn. To evaluate the consistency of the flaking process, we recommend in addition to the determinations of FD, measurements of FT, starch enzymatic reactivity and FS are useful indicators.

In vitro gas production kinetics are influenced by grain processing, flake density, starch retrogradation, and Aspergillus oryzae fermentation extract containing α-amylase activity.

Grain processing such as particle size, flake density, or starch retrogradation can influence ruminal degradability characteristics; however, it is unclear how exogenous α-amylase supplementation interacts with different processed grains. Four experiments were conducted to compare the effects of Aspergillus oryzae fermentation extract (Amaize; Alltech Biotechnology Inc., Nicholasville, KY) supplementation on in vitro gas production kinetics of grain substrates with different processing methods that are common in the feedlot industry. In experiment 1, corn processing (dry-rolled, high-moisture, steam-flaked) and Amaize supplementation (0 or 15 U α-amylase activity/100 mL) were evaluated in a 3 × 2 factorial arrangement of treatments. The rate of gas production for dry-rolled corn was higher (P < 0.001) with Amaize supplementation. In experiment 2, flake density (296, 322, 348, 373, and 399 g/L) and starch retrogradation (storage in heat-sealed foil bags for 3 d at 23 or 55°C) were evaluated in a 5 × 2 factorial arrangement of treatments. There was a flake density × starch retrogradation interaction (P < 0.01) for the rate of gas production because the decrease in the rate of gas production with starch retrogradation was greater at lighter flake densities compared with heavier flake densities. In experiment 3, Amaize supplementation was evaluated across flake densities of nonretrograded steam-flaked corn (stored at 23°C) used in experiment 2. There was a flake density × Amaize interaction (P < 0.01) for the rate of gas production where Amaize supplementation resulted in a lower rate of gas production at lighter flake densities (296, 322, and 348 g/L) but a higher rate of gas production at heavier flake densities (373 and 399 g/L). In experiment 4, Amaize supplementation was evaluated across flake densities of retrograded steam-flaked corn (stored at 55°C) used in experiment 2. Gas production was lower after 24 h with Amaize supplementation for retrograded flakes produced to a density of 322 and 399 g/L while Amaize supplementation did not influence gas production at 24 h at other flake densities. There was a flake density × Amaize interaction for the rate of gas production because Amaize supplementation resulted in a faster (P < 0.01) rate of gas production for all flake densities except retrograded flakes produced to a density of 296 g/L. Enzymatic starch availability was positively correlated with the rate of gas production. These data demonstrate that supplementation of 15 U/100 mL of Amaize resulted in greater rates of gas production for dry-rolled corn, corn steam-flaked to heavier densities, and retrograded steam-flaked corn.

Influence of level of dried distillers grains plus solubles substitution for steam-flaked corn on characteristics of growth performance, and dietary energetics of calf-fed Holstein steers during the initial 16-week growing phase: metabolizable protein versus metabolizable amino acids.

This study evaluates the partial replacement of steam-flaked corn (SFC) with increasing dried distillers grains plus solubles (DDGS) levels in growing-finishing diets for calf-fed Holstein steers. Two experiments were conducted. In trial 1, 100 Holstein calves (136 ± 7 kg) were used to evaluate the effect of DDGS as a metabolizable protein source on cattle growth performance, and dietary energetics of calf-fed Holstein steers during the initial 111 d growing phase. Four dietary levels of DDGS were evaluated (10, 15, 20, and 25%, dry matter basis), replacing SFC (flake density, 0.31 kg/L). In trial 2, four Holstein steers (368 ± 20 kg) with cannulas in the rumen and proximal duodenum were used to evaluate treatment effects on characteristics of ruminal and total tract digestion of organic matter (OM), neutral detergent fiber, nitrogen (N), and indispensable amino acid supply to the small intestine. The increasing level of DDGS did not affect (P ≥ 0.13) average daily gain, gain efficiency, and estimated dietary net energy values. Replacement of SFC with increasing levels of DDGS decreased (linear; P = 0.01) ruminal OM digestion. There was no treatment effect on the flow of microbial nitrogen to the small intestine (P = 0.34) and ruminal microbial efficiency (P = 0.79). However, increasing levels of DDGS in the diet increased (linear; P ≤ 0.04) flow of methionine, histidine, phenylalanine, threonine, leucine, isoleucine, and valine but did not affect (P = 0.74) intestinal supply of lysine. Increasing DDGS in the diet increased (linear, P < 0.01) flow of N to the small intestine but decreased (linear; P < 0.01) ruminal N efficiency. Replacing SFC with DDGS increased intake and amino acid leaving the abomasum. Still, this effect was not sufficient to increase the growth performance of calf-fed Holstein during the first 111 d on feed.

Nutritional value, productive performance, and economic efficiency response to the degree of steam-flaked yellow corn in growing rabbits.

The performance of a corn steam flaker was evaluated to improve steam-flaked corn (SFC) quality and investigate its feeding effects on nutritional value, productive performance, digestibility coefficients,and economic efficiency of growing rabbits. The flaker performance was studied as a function of change in steaming time, steam chest temperatureand roll gap. Performance evaluation of the flaker was carried out in terms of flake thickness (FT), flake density (FD) and processing index (PI) as well as rabbit feeding trials. Experimental results clarified that values of FT, FDand PI are in the optimal limits under conditions of 118°C steam chest temperature, 40 min steaming time and 0.80 mm roll gap. Steam flaking is an acceptable process for rabbit feeds as SFC with optimal FD of between 0.36 and 0.39 kg/L corresponding to a PI of between 50.14% and 54.32% significantly improve the nutritional value of SFCcompared with whole corn grain by 1.31%, 1.26% and 160.75%respectively. Also, SFC severely decreased the total count of harmful bacteria, fungi countand mortality rate compared to whole corn grain. Rabbits fed SFC processed to the density of 0.36 kg/L of the diet had better body weight gain, feed conversion ratio, organic matter digestibility, net revenueand economic efficiency of 9.29%, 8.89%, 4.65%, 15.62%and 15.43% compared with rabbit fed whole yellow corn grainrespectively. In conclusion, it is convenient to entirely substitute whole corn grain with SFC to be utilised in rabbits' diets where achieved the best feeding effects results.

Corn processing, flake density, and starch retrogradation influence ruminal solubility of starch, fiber, protein, and minerals.

Five ruminally cannulated steers (body weight = 390 ± 7.86 kg) were used in three experiments to evaluate effects of corn processing, flake density, and starch retrogradation on in situ ruminal degradation. In experiment 1, corn was left whole or processed with no screen, ground through a 6-mm screen, or ground through a 1-mm screen. In experiment 2, we produced steam-flaked corn at four densities: 309, 335, 360, and 386 g/L. These four flake densities were sifted for 20 s through a 4-mm screen to produce two particle sizes within each flake density: sifted flakes (>4 mm) and sifted fines (<4 mm). In experiment 3, sifted flakes (335 g/L) were stored for 3-d at either 23 °C (starch availability = 55%) or 55 °C to induce starch retrogradation (starch availability = 41%). All samples for each of the three experiments were weighed into nylon bags and ruminally incubated for 0-h to estimate the soluble fraction. The residue remaining was analyzed for nutrient composition. In experiment 1, whole shelled corn had lesser (P < 0.01) ruminal solubility of all nutrients measured compared with ground corn. Corn ground with a screen (6 and 1 mm) had greater (P < 0.01) ruminal solubility of all nutrients measured compared with corn ground with no screen. Corn ground through a 1-mm screen had greater (P < 0.03) ruminal solubility of DM, total starch, CP, ADF, AHF, P, Mg, K, S, Zn, Fe, and Mn compared with corn ground through a 6-mm screen. In experiment 2, increasing flake density linearly decreased (P < 0.02) the soluble fraction of DM, total starch, CP, ADF, AHF, P, K, S, and Zn of sifted flakes. The soluble DM fraction of sifted fines tended to decrease (P = 0.06) linearly with increasing flake density. Total starch, CP, NDF, and Zn soluble fractions of sifted fines were not influenced by flake density. In experiment 3, storage of sifted flakes in heat-sealed foil bags at 55 °C for 3-d decreased (P < 0.04) the soluble fractions of DM, total starch, CP, NDF, P, Mg, K, S, and Fe. With each increase in the degree of corn processing, there was an increase in the solubility of nutrients. Increasing flake density can decrease ruminal solubility of flakes; however, the soluble fraction of sifted fines is not influenced as much by changes in flake density. Inducing starch retrogradation decreases ruminal solubility of starch, nonstarch OM, and minerals.

Flake density and starch retrogradation influence in situ ruminal degradability characteristics of steam-flaked corn and predicted starch digestibility and energetic efficiency.

Five ruminally cannulated steers (body weight = 390 ± 7.86 kg) were used in two experiments to evaluate the effects of flake density and starch retrogradation on in situ ruminal degradation of steam-flaked corn. In experiment 1, sifted flakes with flake densities of 257, 296, 335, 373, and 412 g/L (enzymatic starch availabilities: 87%, 76%, 66%, 43%, and 49%, respectively) were evaluated in a randomized complete block design experiment. In experiment 2, the experimental design was a randomized complete block design with a 3 × 2 factorial arrangement of treatments. Three steam-flaked corn fractions corresponding to different particle sizes were used: flakes + fines (not sifted; >4 and <4 mm), sifted flakes (>4 mm), and sifted fines (<4 mm). Particle size fractions were stored for 3 d at either 23 °C or 55 °C (starch availabilities averaged across particle sizes: 53.3% and 25.5%, respectively) in heat-sealed foil bags. Samples were ruminally incubated for 0, 3, 6, 12, 24, 48, 72, or 96 h. Degradation data were modeled to obtain the rate and extent of degradation and passage rate was set to 6% per hour. In experiment 1, the rate of degradation decreased linearly (P < 0.01) and in situ ruminal dry matter (DM) degradability decreased linearly (P < 0.01) from 78.9% to 57.3% as flake density increased from 257 to 412 g/L. In experiment 2, storage of steam-flaked corn samples at 55 °C for 3 d decreased (P < 0.01) the rate of degradation by 37.6% across all particle sizes. Storing samples at 55 °C for 3 d decreased (P < 0.01) in situ ruminal DM degradability of flakes + fines, sifted flakes, and sifted fines by 20.9%, 22.6%, and 14.7%, respectively. Using data from experiment 1 and 2, enzymatic starch availability of sifted flakes was positively correlated (R2 = 0.97; P < 0.01) with in situ ruminal DM degradability. The results demonstrate that decreased starch availability resulting from either starch retrogradation or increased flake density is associated with decreased ruminal digestibility. Decreases in starch availability and in situ ruminal degradability may indicate that increasing flake density or starch retrogradation could potentially alter the site of digestion in cattle. Using prediction equations, decreases in ruminal starch digestibility of steam-flaked corn caused by increasing flake density or increasing starch retrogradation could increase energetic efficiency, depending on the rate of passage and if small intestinal starch digestibility is maintained.

Improved model of powder blend compacting in a roll compactor

A new mathematical model of mineral fertilizer compacting using a roll compactor is developed. This model is based on the transition to the values of stress tensor components averaged over the cross-sectional area of the powder mixture flow. To define these stresses, equations of equilibrium of the elementary layer determined in the mixture by two planes perpendicular to the flow direction are composed. To obtain relatively simple analytical relations in the calculations, the hypothesis of a power-law dependence of hydrostatic pressure on mixture density, accepted in the framework of the Johansen model, was used. In order to take into account changes in the mechanical characteristics of the mixture (angle of internal friction, coefficient of external friction, transverse strain coefficient) while compacting, we approximated the known experimental dependencies of the corresponding characteristics on the density. The inter-particle cohesion parameter was taken to be proportional to the hydrostatic pressure. The model allows calculating the gap between the rolls surfaces for a given initial bulk density and the required flake density. With the known gap value, the distribution of the axial average stresses in the powder mixture, the normal and shear stresses on the rolls’ surfaces are determined. The results of the calculations of the rolls surface gap and the normal roll pressure diagram are compared with the experimental data given in the literature for the urea compacting process.

PSIV-9 Effective ruminal degradability of steam-flaked corn is influenced by flake density and starch retrogradation

Abstract The objective of this study was to evaluate in situ ruminal digestion characteristics of steam-flaked corn with large differences in starch availability (SA) using two different models: 1) increasing flake density and 2) exposure to 55°C temperatures to induce starch retrogradation. Five ruminally-cannulated steers (body weight = 390 ± 7.86 kg) were pen-fed a starter diet. In Exp. 1, sifted flakes with flake densities of 257, 296, 335, 373, and 412 g/L (SA: 87%, 76%, 66%, 43%, and 49%, respectively) were evaluated. In Exp. 2, three steam-flaked corn fractions were evaluated: flakes + fines (not sifted), sifted flakes (&amp;gt;4-mm), and sifted fines (&amp;lt; 4-mm). Feed fractions were stored for 3-d at either 23°C or 55°C (average SA across steam-flaked corn fractions: 53.3% and 25.5% respectively). Treatments of Exp. 2 were arranged with a 3 × 2 factorial. Both experiments were duplicated and analyzed as randomized complete block designs. In Exp. 1, the fractional rate of degradation linearly decreased (P &amp;lt; 0.001) and effective ruminal dry matter degradability (ERD) linearly decreased (P &amp;lt; 0.001) from 80.8% to 60.3% as flake density increased from 257 to 412 g/L. In Exp. 2, storage of steam-flaked corn samples at 55ºC for 3-d decreased (P &amp;lt; 0.001) the fractional rate of degradation and ERD by 38.6% and 21.7% across all feed fractions, respectively. Using data from Exp. 1 and 2, SA of sifted flakes was positively correlated (Pearson = 0.8435; R2 = 0.71; P &amp;lt; 0.001) to ERD. The results of the current study demonstrate that decreased SA resulting from starch retrogradation or increased flake density is associated with decreased ERD. Decreases in SA and ERD may indicate that increasing flake density or starch retrogradation could potentially alter the site of digestion in cattle, by increasing postruminal starch flows.

Comparison of the effects of dry rolling, temper rolling, and steam flaking barley grain on dry matter intake, growth, and carcass characteristics of finishing beef steers

ABSTRACT Objective The objective of this study was to compare performance of finishing steers fed dry-rolled, temper-rolled, or steam-flaked barley grain when processed to yield a coarse or medium flake. Materials and Methods A total of 420 steers (initial BW ± SD; 375 ± 26 kg), blocked by BW, were randomly assigned to 1 of 4 treatments (15 steers per pen) in a 111-d finishing study. Steers were transitioned to a finishing diet containing (1) dry-rolled barley (DR; 522.1 g/L); (2) temper-rolled barley (TR; 539.7 g/L); or (3) steam-flaked barley at a moderate (MF; 361.0 g/L) or (4) coarse flake density (CF; 450.3 g/L). Dry matter intake, ADG, starch digestibility, fecal starch, and carcass data were collected. Results and Discussion Feeding MF (10.8 kg/d) and CF (11.6 kg/d) decreased DMI relative to DR (12.7 kg/d) and TR (12.7 kg/d). Steers fed MF had lesser ADG (2.16 kg/d; P = 0.009) relative to DR (2.34 kg/d) and TR (2.30 kg/d), whereas CF (2.28 kg/d) was intermediate but not different. The G:F was greater for MF (0.201 kg/kg; P Implications and Applications Steam flaking barley grain may increase feed efficiency by reducing DMI and increasing starch digestibility, but reducing flaking density may negatively affect ADG.

Effects of dietary roughage neutral detergent fiber levels and flint corn processing method on growth performance, carcass characteristics, feeding behavior, and rumen morphometrics of Bos indicus cattle1

Flint corn processing method [coarse ground corn (CGC; 3.2 mm average particle size) or steam-flaked corn (SFC; 0.360 kg/L flake density)] was evaluated in conjunction with 4 levels of NDF from sugarcane bagasse (SCB) as roughage source (RNDF; 4%, 7%, 10%, and 13%; DM basis) to determine impact on growth performance, carcass characteristics, starch utilization, feeding behavior, and rumen morphometrics of Bos indicus beef cattle. Two hundred and forty Nellore bulls were blocked by initial BW (350 ± 37 kg), assigned to 32 feedlot pens and pens within weight block were randomly assigned, in a 2 × 4 factorial arrangement (2 corn processing and 4 levels of RNDF) to treatments. Effects of corn grain processing × RNDF level were not detected (P ≥ 0.14) for growth performance, dietary net energy concentration, carcass traits, rumen morphometrics, and feeding behavior, except for time spent ruminating and time spent resting (P ≤ 0.04), and a tendency for papillae width (P ≤ 0.09). Bulls fed SFC-based diets consumed 7% less (P = 0.001), had 10.6% greater carcass-adjusted ADG (P < 0.001) and 19% greater carcass-adjusted feed efficiency (P < 0.001) compared with bulls fed CGC-based diets. Observed net energy for maintenance and gain values were 14.9% and 19.4% greater (P < 0.001), respectively, for SFC than for CGC-based diets. Fecal starch concentration was less (P < 0.001) for bulls fed SFC compared with those fed CGC. No grain processing effects were detected (P = 0.51) for rumenitis score; however, cattle fed SFC presented smaller ruminal absorptive surface area (P = 0.03). Dry matter intake increased linearly (P = 0.02) and carcass-adjusted feed efficiency tended (P = 0.06) to decrease linearly as RNDF increased. Dietary RNDF concentration did not affect carcass characteristics (P ≥ 0.19), except for dressing percentage, which tended to decrease linearly (P = 0.06) as RNDF in finishing diets increased. Increasing RNDF in finishing diets had no effect (P = 0.26) on time spent eating, but time spent ruminating and resting increased linearly (min/d; P < 0.001) with increased dietary RNDF. Steam flaking markedly increased flint corn energy value, net energy of diets, and animal growth performance, and led to improvements on feed efficiency when compared with grinding, regardless of RNDF content of diets. Increasing dietary RNDF compromised feedlot cattle feed efficiency and carcass dressing.

(Invited) Novel Three-Dimensional Fuzzy Graphene (3DFG)-Based Platform for Interrogation of Excitable Cells

Investigating and modulating electrical activity of cardiomyocytes and neurons is essential to understanding their physiology, regeneration of excitable cells/tissues, and treatment of various disorders. Recently, microelectrode arrays (MEAs) have gained tremendous popularity since they enable multi-site recordings at sub-msec temporal resolution, provide two-way interaction with cells i.e. recording and stimulation, and have well-established microfabrication methods. However, currently used planar MEAs are not able to record and stimulate at sub-cellular resolution due to significant increase in electrode impedance which reduces the signal-to-noise ratio (SNR) of recorded signal. Currently there is a need to (i) enable high density electrode arrays, (ii) provide high spatial resolution, and (iii) prevent averaging of signals from multiple cells. To address these needs, we have developed three-dimensional out-of-plane grown fuzzy graphene (3DFG)-based MEA. Out-of-plane growth of single-to-few layers of graphene flakes leverages graphene's outstanding surface-to-volume ratio. The high surface area leads to significant reduction in impedance, thus enabling electrical recordings with high SNR and development of ultra-microelectrode arrays to perform sub-cellular measurements. Furthermore, the high flake density of graphene in 3DFG lead to high photo-absorbance in UV-NIR range. This opens up avenues to enable photo-thermal stimulation of cells with high precision and sub-cellular resolution. Our presented approach would greatly impact our basic understanding of signal transduction in complex cellular assemblies. Furthermore, it would provide a platform for developing and screening of therapeutics, and treatment of various cardiac and neurological diseases.

Comparative effects of grain source on digestion characteristics of finishing diets for feedlot cattle: steam-flaked corn, barley, wheat, and oats

Twelve Holstein steers (454 ± 32 kg) with cannulas in rumen and proximal duodenum were used in a generalized randomized block design to compare steam-flaked corn (SFC), barley (SFB), wheat (SFW), and oats (SFO) as grain sources (74% of diet dry matter, flake density = 0.31 kg L−1) on characteristics of digestion. Ruminal organic matter (OM) digestion was similar for SFC-, SFB-, and SFW-based diets, but lower for SFO. Ruminal microbial efficiency was greater for SFW and SFO. Given that the undegradable intake protein (UIP) value of SFC is 57%, the comparative UIP values for SFB, SFW, and SFO were 39.8%, 36.1%, and 47.3%, respectively. Ruminal starch digestion was lower for SFC than the other flaked grains. Total-tract OM digestion and digestible energy were greatest for SFC, intermediate for SFB and SFW, and lowest for SFO. Given the net energy maintenance (NEm) value of SFC is 2.40 Mcal kg−1, the comparative NEm value for SFB, SFW, and SFO were 2.25, 2.36, and 2.17 Mcal kg−1, respectively. Steam flaking results in important modifications of small grains that appreciably affect their comparative feeding value. Current standards underestimates the NE value of SFB, SFW, and SFO, and overestimates the UIP values for SFB and SFO.

Tuning Morphology and Defect Density in Self-Assembled Thin-Films of Solvent-Exfoliated WSe2 for Photoelectrochemical Hydrogen Production

The layered semiconducting transition metal dichalcogenides can be exfoliated into atomically-thin 2D sheets offering promising opto-electronic characteristics for application in solar energy conversion. However, the challenges to fabricate high-quality thin films of these 2D sheets using scalable and cost-effective methods limit their practical application. Here we present novel solution-based approaches for large-area semiconducting films of liquid exfoliated WSe2 with controllable flake alignment and defect density, which is leveraged to advance the understanding of the morphological and structural factors on the optoelectronic performance in devices. Specifically, we develop a thin film self-assembly method employing spatial confinement of WSe2 nanoflakes which affords overlapping-free morphology and superior charge transfer character over films with aggregations.[1, 2] The critical roles of the flake edge density, flake lateral size and thickness on the photogenerated charge transport and transfer are established by both experimental (by solution-based flake size sorting) and theoretical (by anisotropic charge transport simulation) routes.[3] In addition, we recently develop approaches to reduce charge recombination at internal crystal defects and surface dangling bonds by applying pre-annealing and surfactant treatments, respectively, which affords a considerable improvement that represents a new benchmark for the performance of solution-processed WSe2. Solar photocurrents for H2 evolution up to 4.0 mA cm–2 (at 0V vs RHE, AM 1.5G illumination), and internal quantum efficiency over 60% are reported for 10 nm thick WSe2 photoelectrodes. [1] Yu X.; Prevot, M. S.; Guijarro, N.; Sivula, K. Nat. Commun. 2015, 6, 7596. [2] Yu X.; Prévot, M. S.; Sivula, K. Chem. Mater. 2014, 26, 5892. [3] Yu, X.; Sivula, K. Chem. Mater. 2017, 29, 6863.

Effects of rumen-degradable protein:rumen-undegradable protein ratio and corn processing on production performance, nitrogen efficiency, and feeding behavior of Holstein dairy cows

This study was conducted to investigate the effects of the ratio of rumen-degradable protein (RDP) to rumen-undegradable protein (RUP) and corn processing method on production performance, nitrogen (N) efficiency, and feeding behavior of high-producing Holstein dairy cows. Twelve multiparous Holstein cows (second parity; milk yield = 48 ± 3 kg/d) were assigned to a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Factor 1 was corn processing method [ground corn (GC) or steam flaked corn (SFC) with a flake density of about 390 g/L], and factor 2 was RDP:RUP ratio [low ratio (LR) = 60:40; high ratio (HR) = 65:35] based on crude protein (%). The crude protein concentrations were kept constant across the treatments (16.7% of DM). No significant interactions of main treatment effects occurred for lactation performance data. Cows fed 2 different RDP:RUP ratios exhibited similar dry matter intake (DMI), but those fed SFC showed decreased feed intake compared with those receiving GC (25.1 ± 0.48 vs. 26.2 ± 0.47 kg/d, respectively). Cows fed HR diets produced more milk than did those fed LR diets (44.4 ± 1.05 vs. 43.2 ± 1.05 kg/d, respectively). Milk fat content decreased but milk protein content increased in cows fed SFC compared with those fed GC. Feed efficiency (i.e., milk yield/DMI) was enhanced with increasing ratio of RDP:RUP (1.68 ± 0.04 vs. 1.74 ± 0.04 for LR and HR, respectively). Apparent N efficiency was higher in cows fed HR than in those fed LR (30.4 ± 0.61 vs. 29.2 ± 0.62, respectively). Compared with cows fed the GC-based diet, those receiving SFC exhibited lower values of N intake, N-NH3 concentration, and fecal N excretion. Cows receiving SFC-based diets spent more time ruminating (min/kg of DMI) than did those fed GC. Although these results showed no interaction effects of RDP:RUP ratio and corn processing method on performance, higher RDP:RUP ratios and ground corn can be effective feeding strategies for feed to lactating cows receiving high-concentrate diets.

Engineered cost-effective growth of Co-based nanoflakes as a sustainable water oxidation electrocatalyst

Developing low-cost, scalable and reproducible synthesis methods for water oxidation reaction (WOR) catalysts is highly desirable and also challenging in energy, environmental and industrial applications. In this context, electrochemical deposition is known as an easy and cost-effective technique in nanomaterial growth. Herein, cobalt-based nanoflakes were grown on a flexible and commercially available steel mesh substrate by electrodeposition approach with a crystalline structure as a mixture of oxide, hydroxide and oxyhydroxide phases. For the first time, the correlation between electrodeposition parameters, time and current density, and morphological characteristics of the grown nanoflakes (density and aspect ratio based on SEM results) has been derived. According to a comprehensive study of the flakes’ electrocatalytic performance in WOR, the optimized sample fabricated with a moderate electrodeposition current density (7 mA cm−2) and duration time (2000 s) revealed the highest density (7.6 × 108 cm−2) and aspect ratio (7.1) as well as the lowest values for overpotential (OP = 324 mV) and charge transfer resistance (14 Ω). This designed array of Co-based nanoflakes also showed the lowest value of overpotential for bare cobalt-based WOR electrocatalysts reported yet. High and low values for deposition current density and/or deposition time had a negative effect on the sample surface, leaving some areas without any flakes or with incomplete and inefficient formation of nanoflakes with low densities and aspect ratios. A similar effect was observed for annealed samples in the range of 200–400 °C. Based on recorded overpotentials and extracted surface morphological parameters, a linear and logarithmic behavior in overpotential–flake density dependency was proposed for current density and time controlled systems, respectively.