Birth traits of Holstein calves compared with Holstein,Jersey, Montbéliarde,Normande, and Viking Red-sired crossbred calves

Holstein (HO) calves, 3-breed crossbred calves of Montbéliarde, Viking Red, and HO (MVH), and 3-breed crossbred calves of Normande, Jersey, and Viking Red (NJV) were compared for gestation length (GL), calf weight at birth (CW), calving difficulty (CD), and stillbirth (SB) in 2 research herds at the University of Minnesota. Calves were born from January 2009 to December 2019. For the St. Paul and Morris herds, HO calves (n = 1,121) were compared with MVH calves (n = 1,393) from primiparous and multiparous cows. For the single herd analysis at Morris, HO calves (n = 476), MVH calves (n = 922), and NJV calves (n = 405) were compared from primiparous and multiparous cows. Primiparous and multiparous births were analyzed separately because multiparous cows had multiple births, and CD and SB are likely different traits for primiparous and multiparous cows. Statistical analysis of GL, CW, CD, and SB included fixed effects of sex of calf, herd, breed group of calf, and year-season of calving. For the St. Paul and Morris herds, HO calves from primiparous (278 d) and multiparous (279 d) HO cows had shorter GL compared with MVH calves from primiparous (280 d) and multiparous (282 d) crossbred cows. The HO calves (39.4 and 43.2 kg, respectively) from primiparous and multiparous HO cows had lower CW compared with MVH calves (40.3 and 44.3 kg, respectively) from primiparous and multiparous crossbred cows. Calving difficulty and SB were not different for HO and MVH calves from primiparous and multiparous cows. For the single herd analysis at Morris, HO calves (278 and 279 d, respectively) from primiparous and multiparous HO cows had shorter GL compared with MVH calves (281 and 282 d, respectively) and NJV calves (282 and 282 d, respectively) from primiparous and multiparous crossbred cows. The CW of HO calves (38.6 and 42.0 kg, respectively) from primiparous and multiparous HO cows was lower compared with MVH calves (39.7 and 42.9 kg, respectively), but higher compared with NJV calves (35.1 and 38.0 kg, respectively) from primiparous and multiparous crossbred cows. Calving difficulty and SB did not differ for HO, MVH, and NJV calves from primiparous and multiparous cows. The longer GL for crossbred calves and higher CW for MVH calves did not increase CD and SB for primiparous and multiparous cows. Dairy producers may implement 3-breed rotational crossbreeding systems that include the HO, Jersey, Normande, Montbéliarde, and Viking Red breeds, and some breeds may increase GL and CW without an increase in CD and SB.     

Complex study of protective Cr3C2–NiAl coatings deposited by vacuum electro-spark alloying,pulsed cathodic arc evaporation,magnetron sputtering,and hybrid technology

Coatings were obtained by vacuum electro-spark alloying (VESA), pulsed cathodic arc evaporation (PCAE), magnetron sputtering (MS) techniques and VESA-PCAE-MS hybrid technology using Cr₃C₂–NiAl electrodes. The structure of the coatings was analyzed using scanning and transmission electron microscopy, X-ray diffraction and energy-dispersive spectroscopy. Mechanical properties were determined by nanoindentation, while tribological properties were assessed using pin-on-disk tribometer. Corrosion resistance was estimated by voltammetry in 1 N H₂SO₄ and 3.5%NaCl solutions. Oxidation resistance tests were performed at 800°С in air. The VESA coating had the highest thickness, low friction coefficient and high wear resistance. PCAE coating demonstrated the highest hardness (24 GPa) and elastic recovery (59%), oxidation resistance and superior corrosion resistance both in 1 N H₂SO₄ (i_corr = 70 μА/cm²) and 3.5%NaCl (i_corr = 0.74 μА/cm²) solutions. The MS coating had average mechanical properties and low corrosion current density (71 μА/cm²) in 1 N H₂SO₄. Deposition of coatings using VESA-PCAE-MS hybrid technology led to an increase in corrosion and oxidation resistance at least by 1.5 times in comparison with the VESA coating.     

A hybrid homogeneously weighted moving average control chart for process monitoring

Several modifications and enhancements to control charts in increasing the performance of small and moderate process shifts have been introduced in the quality control charting techniques. In this paper, a new hybrid control chart for monitoring process location is proposed by combining two homogeneously weighted moving average (HWMA) control charts. The hybrid homogeneously weighted moving average (HHWMA) statistic is derived using two smoothing constants λ₁ and λ₂ . The average run length (ARL) and the standard deviation of the run length (SDRL) values of the HHWMA control chart are obtained and compared with some existing control charts for monitoring small and moderate shifts in the process location. The results of study show that the HHWMA control chart outperforms the existing control charts in many situations. The application of the HHWMA chart is demonstrated using a simulated data.     

Elitist clonal selection algorithm for optimal choice of free knots in B-spline data fitting

Data fitting with B-splines is a challenging problem in reverse engineering for CAD/CAM, virtual reality, data visualization, and many other fields. It is well-known that the fitting improves greatly if knots are considered as free variables. This leads, however, to a very difficult multimodal and multivariate continuous nonlinear optimization problem, the so-called knot adjustment problem. In this context, the present paper introduces an adapted elitist clonal selection algorithm for automatic knot adjustment of B-spline curves. Given a set of noisy data points, our method determines the number and location of knots automatically in order to obtain an extremely accurate fitting of data. In addition, our method minimizes the number of parameters required for this task. Our approach performs very well and in a fully automatic way even for the cases of underlying functions requiring identical multiple knots, such as functions with discontinuities and cusps. To evaluate its performance, it has been applied to three challenging test functions, and results have been compared with those from other alternative methods based on AIS and genetic algorithms. Our experimental results show that our proposal outperforms previous approaches in terms of accuracy and flexibility. Some other issues such as the parameter tuning, the complexity of the algorithm, and the CPU runtime are also discussed.     

冷轧平整机机前甩尾轧制工艺的开发与应用

本文介绍了柳钢冷轧板带厂1550 mm单机架平整机机前甩尾轧制的工艺。改进前轧制每卷钢卷生产效率低,钢卷成材率低,改进后生产效率、成材率明显提高,部分规格的钢卷能实现带尾剪切长度为零。     

Effect of hyperbranched poly(citric polyethylene glycol) with various polyethylene glycol chain lengths on starch plasticization and retrogradation

A series of hyperbranched poly(citric polyethylene glycol) (PCPEG) materials with varied polyethylene glycol (PEG) chain lengths as plasticizers were mixed with maize starch (MS) via cooking and film‐forming. The structure, pasting property, plasticization, aging property, moisture absorption and compatibility of plasticized starches were studied by means of Fourier transform infrared spectroscopy, X‐ray diffraction, rapid viscosity analysis, tension testing, moisture absorption measurements and scanning electron microscopy. Compared with PEG and citric acid, PCPEG was more effective in promoting starch chain movement and inhibiting the retrogradation of starch film. Also, PCPEG/MS had smaller moisture content. The longer the plasticizer chain, the better were the aging resistance and moisture resistance of starch. But with an increase of PEG chain length, mechanical properties of PCPEG/MS deteriorated and the compatibility between PCPEG and MS decreased. The hyperbranched derivative of PEG with longer chain exhibited improved plasticization and compatibility with starch. © 2019 Society of Chemical Industry     

An automated treatment planning strategy for highly noncoplanar radiotherapy arc trajectories

Radiation therapy is a technology-driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head-and-neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high-quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques.     

Contribution of metal vapor mass at periphery part of pulsed arc to electromagnetic force in weld pool

The arc welding has been used in various welding methods because it is inexpensive and high in strength after welding. However, it is a problem that accidents such as collapse of the bridge occur because of the welding defects. The welding of low cost and high productivity is required without the welding defects. The pulsed TIG welding is inexpensive and capable of high‐quality welding. The electromagnetic force contributing to penetration changes because the transient response of arc temperature and iron vapor generated from anode occurs. However, the analysis of pulsed TIG welding with metal vapor has been elucidated only metal vapor concentration near anode with transient phenomenon and heat flux. Thus, the theoretical elucidation of penetration depth with control factor has not been researched. In this paper, the contribution of metal vapor mass at the periphery part of pulsed arc to the electromagnetic force in the weld pool is elucidated. As a result, the iron vapor mass at periphery part decreased with increasing the frequency. The iron vapor was stagnated at axial center within one cycle. The electromagnetic force to the penetration depth direction in weld pool increased at axial center. Therefore, the metal vapor mass at periphery part plays an important role for the electromagnetic force increment at axial center.     

Factors involved in associations between Facebook use and college adjustment: Social competence,perceived usefulness,and use patterns

Although previous research has investigated widespread use of social media, especially Facebook, by youth attending college, the conditions under which these media foster adjustment to college remain unclear. This study tested a model illuminating pathways linking social competence to college adjustment via students’ perceptions about the usefulness of Facebook and ways in which they used the medium. Self-report survey data from 321 college students (M age = 20.09; 58% female; 84% Caucasian) attending a major Midwestern university supported the proposed model, indicating that higher social competence could foster or impede college adjustment, depending upon how it was related to beliefs about the usefulness of different Facebook functions and how these perceptions, in turn, were associated with patterns of Facebook use. Findings underscore the importance of considering connections among personal attributes, perception of media effectiveness, and media behaviors in assessing the implications of social media for users’ psychosocial well-being.     

M1080B无心外圆磨床改进

M1080B无心外圆磨床砂轮及导轮宽度较窄,磨削轴承套圈外圆时,磨削效率低,托板架调整较为繁琐、皮带打滑、磨损较为严重。针对上述问题,提出了相应的解决办法,提高了磨削效率。