Dry Rolling Research Articles

Consideration of Power Transmission Characteristics in a Micro-Gear Train.

Characteristics related to power transmission in the micro-domain, based on dry rolling contact of the gears, were investigated using a 3D-printed gear train with a pitch circle diameter of 84 µm in order to experimentally compare the power transmission efficiency in the macro- and micro-domains. For a basic gear train with two intermeshing gears, it was shown that the gear train in the micro-domain was capable of transmitting power to the same extent as in the macro-domain. However, in gear trains with complex power transmission paths, assuming a planetary gear train with multiple meshing gears, it has been shown that the power transmission characteristics of micro-domain gears differ from those in the macro-domain. The use of gear trains in the micro-region necessitates consideration of the loss of transmitted torque due to contact between tooth surfaces, which is unique to the micro-region and different from its use in the macro-region.

Wear Failure of PEEK-Alumina Ball Bearings in Dry Rolling Contact at 600 rpm - Part 2: Observation of Wear on Retainer

In our previous paper[6], the effects of the retainer wear failure on the friction torque were investigated. In the present paper, to research the failure of the retainers of the PEEK-alumina ball bearings tested under dry rolling contact, the upper and bottom surfaces and the sections of the retainer pockets were observed. The wear damage was found on the surface of the upper and bottom surfaces. On the sections of the pocket, the changes due to wear at the pocket edge was found. On the worn curves of the sections, large scatter of the curvature center positions were numerically calculated in both specimens. The balls moved relatively for the retainer unit to the upper or bottom sides. These results indicate that the wear changed the pocket shape, and the ball could not become to keep the position for the retainer unit. The wear of the pocket caused the failure of the retainer.

Wear Failure of PEEK-Alumina Ball Bearings in Dry Rolling Contact at 600 rpm - Part 1: Effect of Failure due to Wear Damage on Friction Torque

The rolling contact fatigue of PEEK-alumina ball bearings in non-lubrication was tested under 500 N and 600 N. During the tests, the friction torque was measured. The retainers under both conditions broke during the tests, and rubbed on the upper and bottom races. The friction features were not different between 500 N and 600 N. However, the black colored surfaces on the races and retainer were identified only in the test under 600 N. The wear loss of the bearing tested under 600 N was larger than that under 500 N. From these results, the specimen under 600 N received the heavier wear damages than that under 500 N, and the worn surface was not related to the friction torque. The wear damages of the inner elements and the outer rings in the retainer were larger than those of the races and 9-alumina balls in both specimens.

An Experimental Investigation into Roughness Transfer in Asymmetrical Rolling of Steel Strips

This study investigated the effect of rolling parameters such as speed, thickness reduction, roll surface roughness, material thickness, surface condition (dry or lubricated), and rolling force on the roughening characterization in asymmetrical rolling. The surface roughness of the samples subjected to rolling tests was measured. The roughness values' average and standard deviation were found, and 3-D scanning images were acquired. Lubricated texturing experiments revealed that lubrication reduced roughness transfer. It was found that the introduction of roughness on the material surface decreased as the rolling speed increased. On the other hand, a higher speed increases the rolling force, which increases the surface roughness. The effect of speed on the standard deviation varies in direct proportion. Furthermore, lubricated rolling produced a more homogenous roughness distribution at higher speeds, while dry rolling produced homogeneous roughness at lower speeds. It was revealed that the rolling force is higher with thicker materials. While the roll roughness did not affect the rolling force using thicker material much, this effect was more pronounced in the very rough roll using thinner material. The standard deviation was lower in smaller reduction ratios using rough and very rough rolls. According to the results, although asymmetrical rolling has some advantages compared to conventional rolling, it was concluded that it is not a suitable method for roughening steel strips.

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.

159 Effect of dry or Temper Rolling of High or low Protein Wheat and its Impact on Rumen Parameters, Liver Abscesses, and Growth Performance of Feedlot Cattle

Abstract The objective of this study was to assess the impact of low (13%, LP) or high protein (18%, HP) wheat grain subjected to dry (DR) vs temper rolling (TR) on growth performance, rumen parameters, and liver abscesses of feedlot steers. A backgrounding (BG) to finishing (FN) feedlot trial was performed using 160 302 ± 34 kg; 24 ruminally cannulated) Angus steers blocked by weight and randomly assigned to 16 pens. Cannulated steers (3 per pen) were housed within 8 pens equipped with a feed intake monitoring system. BG diets contained 35% wheat grain, 60% barley silage, and 5% supplement on a DM basis. Transition (TN) diets included sequential increases to the proportion of wheat grain in the total mixed ration to achieve a FN diet comprised of 85% wheat grain, 10% barley silage, and 5% supplement. Rumen pHs were measured with an indwelling logger and rumen samples were collected in each phase. Steers fed the HP-DR and LP-TR diets had lower (P≤0.03) ruminal pH than HP-TR during the TN phase. Tempering HP wheat reduced (P&amp;lt;0.001) the generation of fine particles during rolling. During BG and TN, steers fed diets containing HP wheat had higher (P&amp;lt;0.001) ruminal NH3 concentrations than the LP treatments. NH3 measurements during the FN phase were higher (P=0.01) for the LP-DR treatment compared to the LP-TR treatment. Greater (P≤0.01) C2:C3 ratios were noted for HP wheat diets during the BG and FN phases whereas the C2:C3 ratio was reduced (P&amp;lt;0.001) with TR wheat during the FN phase. Greater (P= 0.01) NEgs were assessed for FN steers fed LP wheat. Steers fed HP wheat had more severe (P&amp;lt;0.001) abscesses. Results suggest that HP wheat may limit the growth performance of FN cattle and increase the severity of liver abscesses.

Understanding the efficiency of roll lubrication when rolling AD33 aluminium alloy bands in industrial twin mill 175Ч300

This paper describes the results of a study that looked at the effect of contact conditions (including the use of industrial oil I40 (5%) for roll lubrication) on the deformation performance and power draw of a twin cold mill 175&times;300 operated by the machine building site in Dong Nai, Vietnam, when rolling 0.55 mm thick bands made of aluminium alloy AD33. The initial band size is 0.7&times;100&times;2,000 mm. The authors considered reological properties of the aluminium alloy, as well as the roll lubrication environment, to come up with a rational rolling process designed for 0.55&times;100 mm bands made from 0.7&times;100&times;2,000 mm rolled steel. Due to the use of industrial oil I40 (5%) in the mill 175&times;300, the number of passes could be reduced from three to two. The use of industrial oil I40 (5%) in the twin mill 175&times;300 ensured the specified precision and helped reduce the loads. Compared with dry rolling, due to the use of industrial oil I40 (5%), the rolling force could be lowered by 6 kN (8.3%) in the first pass and the power draw &ndash; by 0.025 kW (3.34%). At the same time, the second pass saved 2.96 kN (5.24%) of rolling force and 0,017 kW (3.95%) of power while ensuring the preset band thickness at the mill exit. Compared with dry rolling, when using I40 oil, the rolling force distribution efficiency along the band length rises by 22.7% in the first pass and by 14.64% in the second pass. When using I40 oil (5%), the strain distribution u nevenness along the band length drops by 39.15% &mdash; from 2.35 to 1.43% in the first pass and by 70.08% &mdash; from 3.81 to 1.14% in the second pass. When using I40 oil (5%), the thickness distribution along the length of aluminium band at the mill exit is more even than when the rolls are dry or use water. It also results in a minimized longitudinal thickness variation &delta;h &ndash; i.e. 0.01 mm. These findings helped develop a rational rolling process for AD33 aluminium alloy bands that relies on the use of industrial oil I40 (5%) to lubricate the rolls of an industrial twin mill, while cutting the loads and saving power.

Effect of processing method and severity for hybrid fall rye on dry matter intake, ruminal fermentation, and apparent total tract nutrient digestibility in ruminally cannulated beef heifers

This study compared dry-rolled and tempered hybrid rye when processed to a coarse or fine severity on dry matter intake (DMI), ruminal fermentation, and apparent total tract nutrient digestibility for beef cattle. Eight ruminally cannulated Simmental heifers (327 ± 33.1 kg, mean ± SD) were used in a replicated 4 × 4 Latin square (21-day periods with 16 days for adaptation and 5 d collection) balanced for carry-over effects with a 2 × 2 factorial arrangement of treatments. Feeding tempered rye increased ( P = 0.01) DMI when compared to dry-rolled rye, but there was no effect of processing severity. Cattle fed dry-rolled rye had a greater ( P = 0.04) area that pH was &lt;5.5 when compared to those fed tempered rye. Feeding dry-rolled rye increased dry matter digestibility ( P = 0.02) and crude protein digestibility ( P = 0.01) when compared to tempered rye, and there was a greater effect to increase total tract starch digestibility with increasing severity of processing for tempering than for dry rolling (interaction, P = 0.03). In conclusion, tempered hybrid rye processed to a fine severity may result in similar total tract starch digestibility to dry-rolled hybrid rye without the marked reductions in DMI and ruminal pH.

Evaluating the effect of finely ground, dry-rolled, and crumbled corn grain on performance, feeding behavior, and starch digestion in Holstein dairy heifers

Corn processing methods including finely ground (FGC), dry rolled (DRC), and crumbled corn (CRC) were evaluated to determine their effects on average daily gain (ADG), structural growth, starch digestibility, feeding behavior, and blood metabolites of young dairy heifers. In this study, 36 Holstein heifers [91 ± 4 d of age, 105 ± 6.5 kg of body weight (BW); mean ± standard deviation] housed in 9 pens (4 heifers per pen) were fed diets (dry matter basis) containing 20% forage (wheat straw) and 80% corn-based concentrate for 60 d. Pens were randomly assigned to 1 of 3 dietary treatments based on the type of corn grain used for the diets: (1) ground corn (FGC; fine: 1.11 ± 0.52 mm); (2) dry-rolled corn (DRC; 2.30 ± 0.68 mm); and (3) crumbled corn (CRC; 2.54 ± 0.70 mm). Heifers had ad libitum access to diets and water throughout the experiment and the feed intake was measured daily. Animals were weighed at the beginning (91 d of age) and end (151 d of age) of the study. The ADG (kg of BW/d) was calculated at the end of experiment at an individual level. Feeding behavior was recorded based on direct observation by monitoring each heifer every 5 min during a 22-h period at 150 d of age. The CRC and DRC tended to increase feed intake compared with FGC, whereas heifers fed CRC tended to have a greater withers height compared with other treatments. Feed efficiency was not affected; however, ADG and final BW increased in heifers fed the CRC diet compared with other diets. Feeding CRC increased total-tract starch digestibility compared with FGC and DRC diets (97.8 vs. 93.1 and 89.5%, respectively). Compared with FGC diet, feeding DRC and CRC tended to increase rumination time. The molar proportion of propionate was greater, and the molar proportion of acetate and acetate-to-propionate ratio were lower in heifers fed CRC than in those fed DRC. The blood glucose and insulin-like growth factor concentrations increased in heifers fed CRC compared with feeding DRC; however, blood urea concentrations decreased by CRC feeding. In conclusion, thermal processing (CRC diet) improved total-tract starch digestibility, ADG, feed intake, and skeletal growth, but had no effect on feed efficiency during the experimental period. Our results indicated that the thermal processing of corn grain improved growth performance of weaned heifers; however, the performance of heifers over a 60-d period did not differ between mechanical processing methods (grinding and dry rolling).

Relationships Between Pulmonary Function and Composite Indices of Femoral Neck Strength in Korean Men (KNHANES IV).

BackgroundDespite the close relationship between osteoporosis and chronic pulmonary diseases, few studies have evaluated relationships between pulmonary functions and bone quality. We investigated associations between pulmonary function test results and femoral neck strength indices (SIs) in Korean men.MethodsThis population-based, cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey IV on 936 men aged ≥ 19 years. Pulmonary functions (forced vital capacity [FVC] and forced expiratory volume in one second [FEV1]) were measured using a dry rolling seal spirometer. Femoral neck SIs, relative to load, were calculated by hip dual-energy X-ray absorptiometry for compression strength index (CSI), bending strength index (BSI), and impact strength index (ISI).ResultsThe 443 (47.3%) of the 936 men were current smokers. FVC, FVC percentage with respect to the expected normal value, FEV1, and FEV1 percentage with respect to the expected normal value (FEV1p) were positively associated with CSI and BSI after adjusting for confounders, including smoking history (β = 0.003–0.223, P = 0.005–0.036). FEV1 and FEV1p were positively associated with ISI (β = 0.000–0.014, P = 0.010–0.025). Of components of femoral neck SIs, bone mineral density was correlated with FEV1 and FEV1p (β = 0.001–0.037, P = 0.017–0.019). After adjusting for all confounders, all femoral neck SIs increased with FVC quintiles (P for trends = 0.001–0.012), and CSI and BSI increased with FEV1 quintiles (P for trends = 0.034–0.043).ConclusionReduced pulmonary function was correlated with reduced femoral neck strength, even after adjusting for smoking history in Korean men. Femoral neck SIs might be useful tools for evaluating bone health in men with reduced pulmonary function.

Hypothesis of the nature of cross-sectional shape distortion of the cold-pilgering mill die groove during dry pipe rolling

The paper provides results on the further development of a method for calculating heat emissions during plastic strain in its instantaneous deformation zone in the course of cold pilgering of pipes, such as the ones that affect the working tool deflection in coldpilgering mills and mechanical properties of wrought pipe metal. It was determined that a decrease in the cross-sectional depth of the coldpilgering mill die groove due to thermal distortions (thermal effect) caused by plastic strain of a pipe in the instantaneous deformation zone is in direct proportion to the distance of the die groove longitudinal section considered to the roll barrel edge. It was found that sections located closer to the roll barrel receive thermal distortion of a lesser degree. A method is proposed for thermal distortion compensation in roll-pass design calculation. Experiments on applying marks on the roll barrel surface near the groove taper showed that the maximum galling of marks takes place directly near tapers. This indicates the local nature of thermal expansion. Dependencies are presented to determine the value of tool geometry variation depending on the heating temperature. The presented dependencies were tested experimentally and were introduced as a basis for developing the method of calculating the transversal die groove parameters for the cold-pilgering mill taking into account local thermal expansion in the instantaneous deformation zone. The inferred law allows taking into account the influence of cold pilgering peculiarities on the variation of the die groove cross-section geometry in the cold-pilgering mill, pipe dimensions and performance parameters.

Method for Calculating Plastic Deformation of High Resolution and Large Contact Area

AbstractIn a rolling contact, the tribological properties in terms of friction, wear, and fatigue are significantly influenced by the surface roughness. Due to solid contact of the surfaces in the contact area, the roughness and thus also the tribological properties change during the service life of the contact. The initial load leads to major changes of the tribological properties figured out by Brecher et al. (2019, “Influence of the Metalworking Fluid on the Micropitting Wear of Gears,” Wear, 61(434–435), p. 202996). Prediction of the initial changes in topography in the contact area is necessary for specific optimization of rolling contacts. Especially for dry rolling–sliding contact, the roughness of the surfaces is crucial for the lifetime, which is part of the investigations within the DFG priority program 2074 (357505886). In this work, an elastic-plastic contact algorithm for calculating plastic deformation for dry contact of rough surfaces with large contact area and high resolution is presented. Due to the nonlinearity behavior associated with plastic deformation, the plastic contact algorithm is based on an iterative approach. An optimized meshing strategy is implemented to calculate the elastic pressure distribution on the surface. Corresponding to the two-dimensional pressure distribution, the three-dimensional stress distribution allows the consideration of residual stresses and interactions of the microscopic peaks of the rough surface. Furthermore, the three-dimensional plastic strain distribution allows the application of an analytical approach to represent the plastic deformation of the surface. Finally, the solution of a plastic contact calculation with an exemplary topography measured on a real rough surface is presented.

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.

408 WS Distinguished Service Talk: Effects of steam flaking on the carbon-footprint of finishing beef cattle

Abstract Grain processing has been used for many decades to improve the digestibility of feed grains fed to finishing beef cattle and to improve animal performance. The most common methods currently used by feedyards in the U.S. are dry rolling (DRC) and steam flaking (SFC). However, the environmental effects of gain processing have not been rigorously studied. This manuscript presents a comparative estimate of the carbon footprint of steam flaking corn in beef cattle finishing diets with and without wet distiller’s grains with solubles (WDGS). Estimates were based on results of published literature and the Intergovernmental Panel on Climate Change. Although SFC required more natural gas and electricity for processing than DRC, feeding SFC decreased the total carbon-footprint by 9 to 13 % per steer. This was primarily due to 30% lower enteric methane production, 13% lower manure nitrous oxide emissions, and 8% lower feed production requirement than when DRC was fed. The carbon-footprints were slightly greater when the diet contained 20% WDGS than when it contained 0% WDGS.

Rolling Friction of Hybrid Ceramic–Steel Pairs under Different Lubrication Conditions

We present the results of a study of a model rolling tribosystem with ceramic balls making a point “ceramic–steel” contact with a flat movable thrust ring under dry rolling friction and under lubrication. The results of laboratory tribotechnical tests enabled a comparative assessment of the wear rate of hybrid “steel–ceramics–steel” model rolling tribosystems with balls made of different ceramic materials. We ranked the studied material in terms of efficiency and improved the technology of rolling elements for hybrid ball bearings. We manufactured prototype hybrid bearings that undergo bench durability tests.

Towards optimisation of rolling process of potato dough: Effect of processing on the microstructure and the mechanical properties

The quality of potato chips is highly dependent on the mechanical properties of the dough sheet produced prior to frying. It has been well established that poor mechanical properties result in fragile dough sheets and associated high product wastage. However, the effect of the rolling process on the mechanical properties of the dough is unknown so the optimum rolling process can only be obtained via a trial and error approach. This work reports for the first time the effects of dry flake size and rolling parameters on the mechanical performance of potato dough sheets. The laboratory scale rolling setup used a 10 cm roller diameter with a 0.2 mm gap height. Furthermore, an experimental method was developed enabling rigorous tensile testing of fragile potato dough sheets. The mechanical performance of the potato dough sheets was anisotropic, as the Young's modulus and strength were 35% and 57% higher across the rolling direction than those along the rolling direction, respectively. The formability, i.e. the ability to form a coherent sheet of the potato dough is improved by using smaller dry flakes (<500 μm). However, further decrease in the flakes size had no effect on the mechanical behaviour of potato dough sheets, i.e. flakes with diameter smaller than 212 μm showed similar tensile response to flakes smaller than 500 μm. Rolling the dough increases the coherence and the strength of the potato dough sheets, but also introduces defects orientated across the rolling direction which decrease the strength if the dough is rolled too many times. For example, sheets rolled for seven passes showed over 100% improvement in failure stress comparing to sheets rolled for five passes, but when the sheets were rolled for the eighth pass, the failure stress dropped by 17%. Due to the viscoelasticity of the dough, both the tensile modulus and strength of the sheets are higher when tested at higher strain rate. In addition, at higher strain rate, the defects in the sheets did not have enough time to grow, as evidenced by a lower scatter in failure stress. A method to obtain an optimum production condition has been identified, which will lead to fewer production interruptions due to dough breakage, and reduced waste. • Investigation on the effect of rolling process on the mechanical behaviour of thin potato dough sheets. • First research on the dry potato flake size-potato dough sheet property relationship. • Design of a novel test gear to perform tensile tests on potato dough sheets and other fragile materials. • Study on the mechanical behaviour of potato dough sheets after rolling process with high compression rate. • Microstructure observation to identify how the change in potato dough microstructure affects the mechanical performance.

Winding Microtubes: Highly Symmetric and Extremely Compact Multiple Winding Microtubes by a Dry Rolling Mechanism (Adv. Mater. Interfaces 13/2020)

A novel dry rolling technique enables rolled-up nanotechnology to create highly symmetric and extremely compact multiple winding microtubes. The technique exploits hydrophobicity of fluorocarbon polymers and thermal expansion mismatch of polymers and inorganic films upon thermal treatment. It opens up possibilities to fabricate highly complex device architectures, which conventional wet chemical etching technologies have not been able to engineer. More details can be found in article number 1902048 by Somayeh Moradi, Oliver G. Schmidt, and co-workers.

Effect of different corn processing methods on starch gelatinization, granule structure alternation, rumen kinetic dynamics and starch digestion

In this study, the effect of four corn processing methods including grinding (G), dry-rolling (DR), steam-flaking (SF) and super-conditioning (SC), on corn starch parameters viz. gelatinization, granule structure alternation, rumen kinetic dynamics and the extent and site of starch digestion were compared. In addition, physical properties, chemical composition, gas production (GP), pH, ammonia nitrogen (NH3-N) and volatile fatty acids (VFAs) of batch culture after 24 h were determined. The apparent density of the SC corn resembled that of the G corn (0.758 vs 0.837 kg/L); however, its geometric mean of particle size (3.39 mm) was greater than that of the G corn (1.56 mm) and smaller than that of the SF corn (5.43 mm). In addition, dry matter (DM), ether extract (EE) and neutral detergent fiber (aNDF) were not significantly affected (P > 0.01) by the processing method. The starch content of the SC and SF corns were greater (P < 0.01) than that of the DR and G corns. GP after 6, 12 and 24-h incubation and GP rate were greater (P < 0.01) in the SC corn; nevertheless, GP at 48-h incubation was the same in SC and SF corns (P> 0.01). The pH and NH3-N of batch culture after 24-h were significantly lower (P < 0.01) in the SC corn than in the other processing methods. The SF corn increased (P < 0.01) acetate and acetate to propionate ratio, but decreased (P < 0.01) propionate while the SC corn reduced (P < 0.01) acetate and acetate to propionate ratio, but raised propionate (P < 0.01). The time required for 25 % and 75 % fermentation of substrate was significantly reduced by the SC corn (P < 0.01). The highest starch gelatinization (P < 0.01) was obtained from SC, followed by SF corn. The rapidly soluble fraction (a) for DM, starch and CP was greater (P < 0.01) in the SC corn than in other processing methods; however, the slowly degradable fraction (b) for DM and starch was lower (P < 0.001) in the SC corn than in other methods. Although the effective rumen degradability of DM (ERDDM) remained unchanged (P> 0.01), the effective rumen degradability of starch (ERDS) and the effective rumen degradability of protein (ERDCP) were found to be greater in the SC corn than in other processing methods (P < 0.01). Ruminal and total tract digestibility of starch increased (P < 0.01) in the SC corn, but intestinal DM (P = 0.002) and starch (P < 0.01) digestibility of the SC corn diminished. The ruminal CP digestibility was lower (P = 0.06) in the SF corn than in the SC corn; however, SC and SF corns showed greater intestinal (P = 0.005) and total tract (P = 0.021) CP digestibility. The results indicated more starch gelatinization in the SC process in terms of higher exposure of particles to conditioning and homogenization, which enabled the alteration of starch granules and the protein matrix in the endosperm of corn. Furthermore, the SC process could influence the rumen kinetic dynamics, the extent and site of starch digestion as well as the efficiency of using starch under in vitro and in situ conditions.

Highly Symmetric and Extremely Compact Multiple Winding Microtubes by a Dry Rolling Mechanism

AbstractRolled‐up nanotechnology has received significant attention to self‐assemble planar nanomembranes into 3D micro and nanotubular architectures. These tubular structures have been well recognized as novel building blocks in a variety of applications ranging from microelectronics and nanophotonics to microbatteries and microrobotics. However, fabrication of multiwinding microtubes with precise control over the winding interfaces, which is crucial for many complex applications, is not easy to achieve by existing materials and technologies. Here, a dry rolling approach is introduced to tackle this challenge and create tight windings in compact and highly symmetric cylindrical microstructures. This technique exploits hydrophobicity of fluorocarbon polymers and the thermal expansion mismatch of polymers and inorganic films upon thermal treatment. Quality parameters for rolled‐up microtubes, against which different fabrication technologies can be benchmarked are defined. The technique offers to fabricate long freestanding multiwinding microtubes as well as hierarchical architectures incorporating rolled‐up wrinkled nanomembranes. This work presents an important step forward toward the fabrication of more complex but well‐controlled microtubes for advanced high‐quality device architectures.

A new seeding method, dry rolling applied to synthesize SAPO-34 zeolite membrane for nitrogen/methane separation

A new seeding method for the secondary growth of zeolite membrane, dry rolling, was applied to synthesize SAPO-34 zeolite membrane. In dry rolling, seeds are introduced on the outer surface of tubular support by mechanically rolling support in a cylindrical container with dry seed particles. During the process, plate-like SAPO-34 seeds fractured into smaller particulates which were uniformly distributed on the support and partially infiltrated into the pores of the support. The low speed and long seeding provided a more homogeneous seed layer due to uniform distribution of fractured tiny seeds and no mechanical damage of support. The homogeneous seed coating reliably developed SAPO-34 separation layer with better performance during the secondary growth process compared with conventional manual rubbing. The membrane synthesized at an optimum condition showed N2/CH4 permselectivity of 4.38 and N2 and CH4 permeance of 399 and 91 GPU, respectively. The performance was comparable or better than generally reported single gas performance, but the performance reliability was much better. Therefore, it could be concluded that dry rolling can be one of the reliable seeding processes for the preparation of zeolite membranes.