50 research outputs found

    Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements

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    This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID) of dry matter, crude protein (CP), and amino acids (AA) of cottonseed meal (CSM), sunflower seed meal (SFSM) and distillers dried grains with solubles (DDGS) by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA) varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP) content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01). The SID of individual RUP-AA was different within specific RUP origin (p<0.01). Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance

    The generalized Hamiltonian model for the shafting transient analysis of the hydro turbine generating sets.

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    yesTraditional rotor dynamics mainly focuses on the steady- state behavior of the rotor and shafting. However, for systems such as hydro turbine generating sets (HTGS) where the control and regulation is frequently applied, the shafting safety and stabilization in transient state is then a key factor. The shafting transient state inevitably involves multiparameter domain, multifield coupling, and coupling dynamics. In this paper, the relative value form of the Lagrange function and its equations have been established by defining the base value system of the shafting. Takingthe rotation angle and the angular speed of the shafting as a link, the shafting lateral vibration and generator equations are integrated into the framework of generalized Hamiltonian system. The generalized Hamiltonian control model is thus established. To make the model more general, additional forces of the shafting are taken as the input excitation in proposed model. The control system of the HTGS can be easily connected with the shafting model to form the whole simulation system of the HTGS. It is expected that this study will build a foundation for the coupling dynamics theory using the generalized Hamiltonian theory to investigate coupling dynamic mechanism among the shafting vibration, transient of hydro turbine generating sets, and additional forces of the shafting.National Natural Science Foundation of China under Grant Nos. 51179079 and 5083900

    Nonlocal shear deformable shell model for thermal postbuckling of axially compressed double-walled carbon nanotubes

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    An investigation is reported of the thermal buckling and postbuckling of axially compressed double-walled carbon nanotubes (CNTs) subjected to a uniform temperature rise. The double-walled carbon nanotube is modeled as a nonlocal shear deformable cylindrical shell, which contains small-scale effects and van der Waals interaction forces. The governing equations are based on higher order shear deformation shell theory with a von Karman-Donnell-type of kinematic nonlinearity and include thermal effects. Temperature-dependent material properties, which come from molecular dynamics (MD) simulations, and an initial point defect, which is simulated as a dimple on the tube wall, are both taken into account. The small-scale parameter, e0a, is estimated by matching the buckling temperature of CNTs observed from the MD simulation results with the numerical results obtained from the nonlocal shear deformable shell model. The numerical illustrations concern the thermal postbuckling response of perfect and imperfect, single- and double-walled CNTs with different values of compressive load ratio. The results show that buckling temperature and postbuckling behavior of nanotubes are very sensitive to the small-scale parameter. The results reveal that temperature-dependent material properties have a significant effect on the thermal postbuckling behavior of both single- and double-walled CNTs

    Integrated Evaluation of the Water Deficit Irrigation Scheme of Indigowoad Root under Mulched Drip Irrigation in Arid Regions of Northwest China Based on the Improved TOPSIS Method

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    Limited water resources and low water productivity limit the sustainable development of agriculture in northwest China. In this study, drip irrigation under plastic film was used to achieve an optimal water deficit irrigation (WDI) scheme for the cultivation of indigowoad root (Isatis tinctoria L.). Field water control experiments were conducted in 2016 and 2017. Evaluation of WDI schemes was carried out by considering five indices: water consumption, yield, water use efficiency (WUE), indigo, and (R,S)-goitrin. To enhance the reliability of results, the analytic hierarchy process (AHP) and entropy weight method (EWM) were adopted to calculate the combined weight of the evaluation index. Finally, an improved technique for order of preference by similarity to ideal solution (TOPSIS) that integrated AHP–EWM weights was used to construct a unified, comprehensive evaluation model of indigowoad root under mulched drip irrigation that would produce high yield while saving water. The evaluation results indicated that mild WD (specifically, the V1G1 treatment) was continuously exerted during the vegetative and fleshy root growth periods, which enhanced the WUE and improved the quality of indigowoad root to a certain extent without significantly reducing the yield. These results provide a scientific basis for irrigation of indigowoad in northwest China and other areas with a similar environment

    Photosynthetic Characteristics and Yield Response of <i>Isatis indigotica</i> to Regulated Deficit Irrigation in a Cold and Arid Environment

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    Water resource scarcity is an important factor restricting the sustainable development of agriculture in Northwest China. Regulated deficit irrigation can conserve water while maintaining high crop yields. A field experiment was conducted to evaluate the effect of regulated deficit irrigation on the photosynthetic characteristics, yield, and water use efficiency of woad (Isatis indigotica) under mulched drip irrigation from 2017 to 2019 in a cold and arid area of the Hexi Oasis irrigation region, China. Sufficient water was supplied during the seedling stage. The control consisted of adequate water supplied during the other growth stages, whereas mild, moderate, and severe water deficits were imposed during the vegetative growth period, and a mild and moderate water deficit was imposed during the fleshy root growth stage. A mild water deficit was imposed during the fleshy root maturity period. The results showed that the net photosynthetic rate, transpiration rate, and stomatal conductance under moderate and severe water deficit were significantly (p p > 0.05) from that of the control. Other treatments caused a 6.74–17.74% reduction in the economic yield of woad. The water use efficiency and irrigation water use efficiency were the highest in the mild water deficit during the vegetative growth period and the fleshy root growth period. Therefore, the application of a continuous mild deficit from the vegetative growth stage to the fleshy root growth stage with sufficient water supplied during other growth periods is recommended as the optimal irrigation regime for maximum yield, water use efficiency, and water-saving of woad

    Photosynthetic Characteristics and Yield Response of Isatis indigotica to Regulated Deficit Irrigation in a Cold and Arid Environment

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    Water resource scarcity is an important factor restricting the sustainable development of agriculture in Northwest China. Regulated deficit irrigation can conserve water while maintaining high crop yields. A field experiment was conducted to evaluate the effect of regulated deficit irrigation on the photosynthetic characteristics, yield, and water use efficiency of woad (Isatis indigotica) under mulched drip irrigation from 2017 to 2019 in a cold and arid area of the Hexi Oasis irrigation region, China. Sufficient water was supplied during the seedling stage. The control consisted of adequate water supplied during the other growth stages, whereas mild, moderate, and severe water deficits were imposed during the vegetative growth period, and a mild and moderate water deficit was imposed during the fleshy root growth stage. A mild water deficit was imposed during the fleshy root maturity period. The results showed that the net photosynthetic rate, transpiration rate, and stomatal conductance under moderate and severe water deficit were significantly (p &lt; 0.05) decreased compared with the control, respectively, during the vegetative growth period. The economic yield of mild water deficit during the vegetative growth and mild water deficit during the vegetative growth and fleshy root growth did not differ significantly (p &gt; 0.05) from that of the control. Other treatments caused a 6.74&ndash;17.74% reduction in the economic yield of woad. The water use efficiency and irrigation water use efficiency were the highest in the mild water deficit during the vegetative growth period and the fleshy root growth period. Therefore, the application of a continuous mild deficit from the vegetative growth stage to the fleshy root growth stage with sufficient water supplied during other growth periods is recommended as the optimal irrigation regime for maximum yield, water use efficiency, and water-saving of woad

    The effect of health literacy and self-management efficacy on the health-related quality of life of hypertensive patients in a western rural area of China: a cross-sectional study

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    Abstract Background Hypertension is a common and frequently occurring chronic disease of the cardiovascular system. Besides the pathological factors, the occurrence and exacerbation of hypertension are also associated with many factors of lifestyle and behaviors. Thus hypertensive patients’ Health-related quality of life (HRQL) is not only influenced by the disease itself but also by many subjective factors such as health literacy and self-management efficacy, especially in the deeper part of southwestern China and thus is less developed compared to the other places. The purpose of this study was to examine the association between the HRQL of hypertensive patients and health literacy and self-management efficacy as well as how they affect the HRQL, so as to provide a theoretical reference for improving the HRQL of patients with hypertension in less developed areas. Methods This was a cross-sectional study of baseline data from a clustered randomized controlled trial. The study design had passed a cross-national peer review and accepted grants by the China Medical Board. It was also registered in the Chinese Clinical Trial Registry (ChiCTR-OOR-14005563). A standardized questionnaire adapted from a previous validated WHO questionnaire was used for the survey which included detailed questions about patient’s socio-demographic characteristics and self-reported information. Patients’ HRQL was measured by the Mandarin version of the 36-item Short Form. We used the validated Mandarin version of the Self-Efficacy for Managing Chronic Disease 6-Item Scale to assess patients’ self-management efficacy. The validated three-item Brief Health Literacy Screening (BHLS) was used to measure the patients’ health literacy. A structural equation model was constructed, and p ≤ 0.05 was taken as significant. Results Demographic characteristics, health literacy and self-management efficacy have all significant effects on HRQL. Age, education level, self-management efficacy and health literacy were significantly related to the HRQL. The constructed model had a good fit for the data according to the model fit indices. Based on the model, health literacy (r = 0.604, p = 0.029) and Self-management efficacy (r = 0.714, p = 0.018) have a significant impact on HRQL. Demographic characteristics were inversely related to HRQL (r = −0.419, p = 0.007), but have a significant impact on health literacy (r = 0.675, p = 0.029) and self-management efficacy (r = 0.379, p = 0.029). At the same time, self-management efficacy was positively correlated to health literacy (r = 0.413, p < 0.01). Conclusions Age, education level, self-management efficacy and health literacy were all related to the HRQL of patient with hypertension, which means that patients who are more elderly and have lower education level, low self-management efficacy and poor health literacy get worse HRQL. This may imply the necessary to introduce routine assessment of health literacy and self-management efficacy into assessment procedures for hypertensive patients’ health management. Such assessment can help professionals to identify the population at greatest risk for poor health outcomes and low well-being in the future. In clinical practice, effective interventions such as direct guidance and education to raise the self-management efficacy and enhance health literacy might improve the HRQL of patients with hypertension. Trial registration Retrospectively registered Chinese Clinical Trial Registry ( ChiCTR-OOR-14005563 ). Name of registry: Effects of the integrated delivery system and payment system of community-based intervention on rural patients of chronic diseases in Qianjiang District, China Date of registration: Retrospectively registered 23 November 2014. Date of enrolment of the first participant to the trial: 5 July 201
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