Comparative Evaluation of Cooling Systems for Farrowing Sows

The field studies reported here compare the performance of three cooling systems for relieving farrowing/lactating sows of heat stress under the warm and humid production climate in southern China. The comparative systems included (1) tunnel ventilation (TV) with vertical head-zone ventilation (HZV) vs. TV with HZV and drip cooling (DC), (2) TV only vs. TV with DC, and (3) horizontal air mixing (HAM) only vs. HAM and DC. For the HZV, a perforated overhead air duct was used to create an air velocity of 0.6 to 0.8 m/s (118 to 157 ft/min) in the head zone of the sow. The paired tests were conducted successively in an experimental commercial farrowing barn housing 42 sows. Body temperature (Tb) and respiration rate (RR) of the sows were used to evaluate the efficacy of the systems. The results indicate that sows under TV + DC or TV + HZV + DC had significantly lower Tb than those under TV only or TV + HZV (P \u3c 0.01 and P \u3c 0.001, respectively). DC under HAM was less effective for Tb reduction (P \u3e 0.05). DC reduced RR in all cases, 42% under TV (P \u3c 0.01), 41% under TV + HZV (P \u3c 0.01), and 22% under HAM (P \u3e 0.05). It was concluded that TV with DC provides the most cost-effective cooling scheme

Temporal Variation of Greenhouse Gas Emission in Gestation Swine Building

The objective of this study was to examine the temporal variation of greenhouse gas (GHG) concentration in the swine building over both daily and seasonal basis. The air samples were collected every one hour continuously for three days during summer and spring, and analyzed by gas chromatography (GC). Barn temperature was collected and the management practices were also noted. Results showed that methane (CH4) and carbon dioxide (CO2) concentration was related to the internal temperature and ventilation. Daily CH4 and CO2 concentrations varied more during cold weather than warmer weather; nighttime GHG concentration in the gestation building was higher than daytime because of the low air exchange. Average CH4 concentration in the gestation building was 16.67 + 9.88 ppm in spring and 9.25 + 7.64 ppm in summer. Average CO2 concentrations were 2361.65 + 960.96 ppm in spring and 1134.96 + 373.53 ppm in summer

Interpretation and prediction of optical properties: novel fluorescent dyes as a test case

The rapid development of modern quantum mechanical theories and computational resources facilitates extended characterization of molecular systems of increasing size and complexity, including chromophores of biochemical or technological interest. Efficient and accurate computations of molecular structure and properties in the ground and excited electronic states are routinely performed using density functional theory (DFT) and its time-dependent (TD-DFT) counterpart. However, the direct comparison with experiment requires simulation of electronic absorption or emission spectra, for which inclusion of vibrational effects leads to more realistic line shapes while at the same time allowing for more reliable interpretation and prediction of optical properties and providing additional information that is not available from experimental low-resolution UV-vis spectra. Computational support can help identify the most interesting chromophores among a large number of potential candidates for designing new materials or sensors, as well as unraveling effects contributing to the overall spectroscopic phenomena. In this perspective, recently developed viologen derivatives (1,1′-disubstituted-4,4′-bipyridyl cation salts, viol) are selected as test cases to illustrate the advantages of spectroscopic theoretical methodologies, which are still not widely used in “chemical” interpretation. Although these molecules are characterized by improved stability as well as the dual function of chromism and luminescence, their detailed spectroscopic characterization is hampered due to the availability of only low-resolution experimental spectra. DFT-based absorption and emission spectra are exploited in the analysis of optical properties, allowing detailed investigation of vibrational effects and gaining more insights on the structure–spectra relationship, which can be extended to develop further viologen dyes with improved optical properties

The growing inequality between firms

Globalisation, technological progress and a range of policies and institutions are driving ‘Great Divergences’ in wages and productivity, write Giuseppe Berlingieri, Patrick Blanchenay and Chiara Criscuol

Mapping knowledge structures and theme trends of atopic dermatitis: a co-word biclustering and quantitative analysis of the publication between 2015 and 2019

Background Atopic dermatitis (AD) has been a hot research direction of dermatologists for a long time. However, the knowledge structures and theme trends for AD have not yet been studied bibliometrically. Objective To investigate the distribution pattern and knowledge structure of AD related literatures in PubMed. Methods Bibliographic information was generated by the Bibliographic Item Co-Occurrence Matrix Builder (BICOMB). A visual matrix was created by the gCLUTO software. GraphPad Prism 5 software was used to construct a Strategic diagram analysis. Ucinet 6.0 software and NetDraw 2.084 software were used to generate a social network analysis (SNA). Results Among all the extracted MeSH terms and subheadings, 77 MeSH terms/MeSH subheadings with a high-frequency were identified, and hot topics were gathered together into 6 groups. In the strategic diagram, immunology, microbiology, and drug therapy of AD were fully developed. In contrast, prevention, pathology, genetics, metabolism, administration, cost of illness, quality of life therapeutic paradigm, and immunosuppressive agents of AD were considerably immature offering prospective scope for further research. Conclusions The results may potentially aid in describing an all-round grasp of the current research areas and furnish guidelines for the researchers for beginning new projects

Uptake Fluoride from Water by Starch Stabilized Layered Double Hydroxides

A novel starch stabilized Mg/Al layered Double hydroxides (S-LDHs) was prepared in a facile approach and its fluoride ion removal performance was developed. Characterization of S-LDHs was employed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and particle size distribution. The adsorption property was studied through the assessment of the adsorption isotherms, kinetic models, thermal dynamics, and pH influence. The result shows that a low loading of starch of 10 mg onto layered double hydroxides (LDHs) could obviously improve the fluoride removal rate. The S-LDHs had three times higher the adsorption capacity to fluoride than that of Mg/Al LDHs to fluoride. The particle size was smaller and the particle size distribution was narrower for S-LDHs than that for Mg/Al LDHs. The Langmuir adsorption isotherm model and pseudo-second-order kinetic model fitted well with the experimental data. In thermodynamic parameters, the enthalpy (ΔH0) value was 35.63 kJ·mol−1 and the entropy (ΔS0) value was 0.0806 kJ·mol−1K−1. The values of ΔG0 were negative, implying the adsorption process is spontaneous. S-LDHs reveals stable adsorption property in a wide pH range from 3 to 9. The mechanism for fluoride adsorption on S-LDHs included surface adsorption and interaction ion exchange