Design and experiments of an automatic pipe winding machine

To solve the time-consuming and laborious problem of manual winding and unwinding water pipes by field workers during irrigation or pesticide spraying in agricultural production, an automatic pipe winding machine for winding and unwinding water pipes was designed. The guiding mechanism, pipe winding mechanism, and pipe arrangement mechanism of the pipe winding machine are designed, and the automatic deviation correction control method of pipe arrangement based on PID and the constant tension control method of pipe winding and unwinding is put forward, and the control system of the automatic pipe winding machine is developed. By making a prototype of an automatic pipe winding machine, the effects of pipe winding and unwinding and the constant tension control of the automatic winding machine are tested and analyzed. The test results show that under the condition of 4.0 km/h speed, the maximum angle error of the automatic pipe winding machine is 3.32°, the average absolute error is 0.95°, and the water pipes are arranged neatly and tightly. The maximum relative error of the water pipe tension is 9.3%, and the maximum relative error under the 0~4.0 km/h velocity step variable condition is 16.3%. The speed of the pipe winding and unwinding can adapt to the change of the vehicle’s speed automatically, and the tension of the pipe is within a reasonable range. The performance of the pipe arrangement and pipe coiling of the automatic pipe winding machine can meet the operating requirements

Causal association of NAFLD with osteoporosis, fracture and falling risk: a bidirectional Mendelian randomization study

IntroductionThe causal association between non-alcoholic fatty liver disease (NAFLD) and osteoporosis remains controversial in previous epidemiological studies. We employed a bidirectional two-sample Mendelian analysis to explore the causal relationship between NAFLD and osteoporosis.MethodThe NAFLD instrumental variables (IVs) were obtained from a large Genome-wide association study (GWAS) meta-analysis dataset of European descent. Two-sample Mendelian randomization (MR) analyses were used to estimate the causal effect of NAFLD on osteoporosis, fracture, and fall. Reverse Mendelian randomization analysis was conducted to estimate the causal effect of osteoporosis on NAFLD. The inverse-variance weighted (IVW) method was the primary analysis in this analysis. We used the MR-Egger method to determine horizontal pleiotropic. The heterogeneity effect of IVs was detected by MR-Egger and IVW analyses.ResultsFive SNPs (rs2980854, rs429358, rs1040196, rs738409, and rs5764430) were chosen as IVs for NAFLD. In forward MR analysis, the IVW-random effect indicated the causal effect of NAFLD on osteoporosis (OR= 1.0021, 95% CI: 1.0006-1.0037, P= 0.007) but not on fracture (OR= 1.0016, 95% CI: 0.998-1.0053, P= 0.389) and fall (OR= 0.9912, 95% CI: 0.9412-1.0440, P= 0.740). Furthermore, the reverse Mendelian randomization did not support a causal effect of osteoporosis on NAFLD (OR= 1.0002, 95% CI: 0.9997-1.0007, P= 0.231). No horizontal pleiotropic was detected in all MR analyses.ConclusionsThe results of this study indicate a causal association between NAFLD and osteoporosis. NAFLD patients have a higher risk of osteoporosis but not fracture and falling risk. In addition, our results do not support a causal effect of osteoporosis on NAFLD

Complexation state of iron and copper in ambient particulate matter and its effect on the oxidative potential

Transition metals have long been recognized as an important component contributing to the toxicological property of ambient particulate matter (PM). Various methods of assessing this toxicity have been applied, including measuring the capability of PM components to generate reactive oxygen species (ROS), and the capability of consuming antioxidants. However, whether transition metals are complexed with organic compounds or free in ambient PM, which could be an important factor determining their ability to generate ROS, is not well understood. We target to investigate the complexation states of important atmospheric metals in this study. A novel fractionation scheme is developed to separate Fe and Cu from ambient PM into hydrophilic, hydrophobic and inorganic fractions. The scheme has been validated by applying it on a mixture of Suwannee River fulvic acid (SRFA) and Fe or Cu. SRFA is selected as a model compound as it represents the humic-like substances present in ambient PM, which are believed to be complexed with Fe and Cu. The results show that a significant amount of iron pre-mixed with SRFA is detected in both hydrophobic and hydrophilic fractions, indicating potential complexation with both types of organic substances. Similar tests conducted with the ambient PM show up to 70-80% of iron complexed with organic compounds. Fe and SRFA show strong synergistic effect in the generation of hydroxyl radical in different antioxidants systems (surrogate lung fluid, ascorbic acid and dithiolthreitol), which is attributed to the higher efficiency of Fe-SRFA complexes to convert H2O2 to ∙OH (Fenton reaction) than Fe alone. Although, Cu and SRFA show additive effect in ∙OH production, while they are antagonistic in the consumption of antioxidants (ascorbic acid and glutathione). Overall, the organic complexation of metals in ambient PM could significantly alter the oxidative potential of ambient PM and needs to be accounted for apportioning the contribution of metals in aerosol toxicity

Complexation state of iron and copper in ambient particulate matter and its effect on the oxidative potential

Transition metals have long been recognized as an important component contributing to the toxicological property of ambient particulate matter (PM). Various methods of assessing this toxicity have been applied, including measuring the capability of PM components to generate reactive oxygen species (ROS), and the capability of consuming antioxidants. However, whether transition metals are complexed with organic compounds or free in ambient PM, which could be an important factor determining their ability to generate ROS, is not well understood. We target to investigate the complexation states of important atmospheric metals in this study. A novel fractionation scheme is developed to separate Fe and Cu from ambient PM into hydrophilic, hydrophobic and inorganic fractions. The scheme has been validated by applying it on a mixture of Suwannee River fulvic acid (SRFA) and Fe or Cu. SRFA is selected as a model compound as it represents the humic-like substances present in ambient PM, which are believed to be complexed with Fe and Cu. The results show that a significant amount of iron pre-mixed with SRFA is detected in both hydrophobic and hydrophilic fractions, indicating potential complexation with both types of organic substances. Similar tests conducted with the ambient PM show up to 70-80% of iron complexed with organic compounds. Fe and SRFA show strong synergistic effect in the generation of hydroxyl radical in different antioxidants systems (surrogate lung fluid, ascorbic acid and dithiolthreitol), which is attributed to the higher efficiency of Fe-SRFA complexes to convert H2O2 to ∙OH (Fenton reaction) than Fe alone. Although, Cu and SRFA show additive effect in ∙OH production, while they are antagonistic in the consumption of antioxidants (ascorbic acid and glutathione). Overall, the organic complexation of metals in ambient PM could significantly alter the oxidative potential of ambient PM and needs to be accounted for apportioning the contribution of metals in aerosol toxicity.U of I OnlyAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD syste

Unraveling Mechanisms of Reactive Oxygen Species Formation from Secondary Organic Aerosols

Reactive oxygen species (ROS), including the hydroxyl radical (•OH), superoxide (O2•-), hydroperoxyl radical (HO2•) and hydrogen peroxide (H2O2), play a central role in chemical transformation and health effects of atmospheric aerosols. Respiratory deposition of secondary organic aerosols (SOA) and transition metals may lead to the generation of ROS to cause oxidative stress, but the underlying mechanism and formation kinetics of ROS are not well understood. Using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping technique, the ROS formation is characterized from aqueous reactions of SOA involving transition metals, lung antioxidants, reaction media with different pH as well as photoirradiation. First, we demonstrate dominant formation of superoxide (O2•-) with molar yields of 0.01 – 0.03% from aqueous reactions of biogenic SOA generated by •OH photooxidation of isoprene, β-pinene, α-terpineol, and d-limonene. The temporal evolution of •OH and O2•- formation is elucidated by kinetic modeling with a cascade of aqueous reactions including the decomposition of organic hydroperoxides, •OH oxidation of primary or secondary alcohols, and unimolecular decomposition of α-hydroxyperoxyl radicals. Relative yields of various types of ROS reflect relative abundance of organic hydroperoxides and alcohols contained in SOA. In addition, we observed substantial formation of organic radicals in surrogate lung fluid (SLF) by mixtures of Fe2+ and SOA generated from photooxidation of isoprene, α-terpineol and toluene. The molar yields of organic radicals by SOA are measured to be 0.03 – 0.5% in SLF, which are 5 – 10 times higher than in water. We observe that Fe2+ enhances organic radical yields dramatically by a factor of 20 – 80, which can be attributed to Fe2+-facilitated decomposition of organic peroxides, consistent with a positive correlation between peroxide contents and organic radical yields. Ascorbate mediates redox cycling of iron ions to sustain organic peroxide decomposition, as supported by kinetic modeling reproducing time- and concentration-dependence of organic radical formation as well as additional experiments observing the formation of Fe2+ and ascorbate radicals in mixtures of ascorbate and Fe3+. •OH and superoxide are found to be scavenged by antioxidants efficiently. Furthermore, we find highly distinct radical yields and composition at different pH in the range of 1 – 7.4 from SOA generated by oxidation of isoprene, α-terpineol, α-pinene, β-pinene, toluene and naphthalene. We observe that isoprene SOA have substantial hydroxyl radical (•OH) and organic radical yields at neutral pH, which are 1.5 – 2 times higher compared to acidic conditions in total radical yields. Superoxide (O2•-) is found to be the dominant species generated by all types of SOA at lower pH. At neutral pH, α-terpineol SOA exhibit a substantial yield of carbon-centered organic radicals, while no radical formation is observed by aromatic SOA. Further experiments with model compounds show that the decomposition of organic peroxide leading to radical formation may be suppressed at lower pH due to acid-catalyzed rearrangement of peroxides. We also observe 1.5 – 3 times higher molar yields of hydrogen peroxide (H2O2) in acidic conditions compared to neutral pH by biogenic and aromatic SOA, likely due to enhanced decomposition of α-hydroxyhydroperoxides and quinone redox cycling, respectively. Finally, we identify that photoirradiation can induce efficient formation of organic radicals from SOA with radical yields up to 1.5%, ~ 100 times higher compared to dark conditions. Further experiments show that total peroxide fractions in SOA decrease 50 – 70% after irradiation, indicating organic peroxides as a probable source of organic radical formation. High resolution mass spectrometry (HR-MS) confirms the substantial formation of organic radicals by identifying BMPO-organic radical adducts, which may provide insights into the chemical structures of these organic radicals and subsequently their formation mechanisms. These findings and mechanistic understanding have important implications on the atmospheric fate of SOA and particle-phase reactions of highly oxygenated organic molecules as well as oxidative stress upon respiratory deposition

Effects of Acidity on Reactive Oxygen Species Formation from Secondary Organic Aerosols.

Reactive oxygen species (ROS) play a critical role in the chemical transformation of atmospheric secondary organic aerosols (SOA) and aerosol health effects by causing oxidative stress in vivo. Acidity is an important physicochemical property of atmospheric aerosols, but its effects on the ROS formation from SOA have been poorly characterized. By applying the electron paramagnetic resonance spin-trapping technique and the Diogenes chemiluminescence assay, we find highly distinct radical yields and composition at different pH values in the range of 1-7.4 from SOA generated by oxidation of isoprene, α-terpineol, α-pinene, β-pinene, toluene, and naphthalene. We observe that isoprene SOA has substantial hydroxyl radical (•OH) and organic radical yields at neutral pH, which are 1.5-2 times higher compared to acidic conditions in total radical yields. Superoxide (O2 •-) is found to be the dominant species generated by all types of SOAs at lower pH. At neutral pH, α-terpineol SOA exhibits a substantial yield of carbon-centered organic radicals, while no radical formation is observed by aromatic SOA. Further experiments with model compounds show that the decomposition of organic peroxide leading to radical formation may be suppressed at lower pH due to acid-catalyzed rearrangement of peroxides. We also observe 1.5-3 times higher molar yields of hydrogen peroxide (H2O2) in acidic conditions compared to neutral pH by biogenic and aromatic SOA, likely due to enhanced decomposition of α-hydroxyhydroperoxides and quinone redox cycling, respectively. These findings are critical to bridge the gap in understanding ROS formation mechanisms and kinetics in atmospheric and physiological environments

HeLoDL: Hedgerow Localization Based on Deep Learning

Accurate localization of hedges in 3D space is a key step in automatic pruning. However, due to the irregularity of the hedge shape, the localization accuracy based on traditional algorithms is poor. In this paper, we propose a deep learning approach based on a bird’s-eye view to overcoming this problem, which we call HeLoDL. Specifically, we first project the hedge point cloud top-down as a single image and, then, augment the image with morphological operations and rotation. Finally, we trained a convolutional neural network, HeLoDL, based on transfer learning, to regress the center axis and radius of the hedge. In addition, we propose an evaluation metric OIoU that can respond to the radius error, as well as the circle center error in an integrated way. In our test set, HeLoDL achieved an accuracy of 90.44% within the error tolerance, which greatly exceeds the 61.74% of the state-of-the-art algorithm. The average OIoU of HeLoDL is 92.65%; however, the average OIoU of the best conventional algorithm is 83.69%. Extensive experiments demonstrated that HeLoDL shows considerable accuracy in the 3D spatial localization of irregular models

<i>HeLoDL</i>: Hedgerow Localization Based on Deep Learning

Accurate localization of hedges in 3D space is a key step in automatic pruning. However, due to the irregularity of the hedge shape, the localization accuracy based on traditional algorithms is poor. In this paper, we propose a deep learning approach based on a bird’s-eye view to overcoming this problem, which we call HeLoDL. Specifically, we first project the hedge point cloud top-down as a single image and, then, augment the image with morphological operations and rotation. Finally, we trained a convolutional neural network, HeLoDL, based on transfer learning, to regress the center axis and radius of the hedge. In addition, we propose an evaluation metric OIoU that can respond to the radius error, as well as the circle center error in an integrated way. In our test set, HeLoDL achieved an accuracy of 90.44% within the error tolerance, which greatly exceeds the 61.74% of the state-of-the-art algorithm. The average OIoU of HeLoDL is 92.65%; however, the average OIoU of the best conventional algorithm is 83.69%. Extensive experiments demonstrated that HeLoDL shows considerable accuracy in the 3D spatial localization of irregular models

Photoenhanced Radical Formation in Aqueous Mixtures of Levoglucosan and Benzoquinone: Implications to Photochemical Aging of Biomass-Burning Organic Aerosols.

The photochemical aging of biomass-burning organic aerosols (BBOAs) by exposure to sunlight changes the chemical composition over its atmospheric lifetime, affecting the toxicological and climate-relevant properties of BBOA particles. This study used electron paramagnetic resonance (EPR) spectroscopy with a spin-trapping agent, 5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO), high-resolution mass spectrometry, and kinetic modeling to study the photosensitized formation of reactive oxygen species (ROS) and free radicals in mixtures of benzoquinone and levoglucosan, known BBOA tracer molecules. EPR analysis of irradiated benzoquinone solutions showed dominant formation of hydroxyl radicals (•OH), which are known products of reaction of triplet-state benzoquinone with water, also yielding semiquinone radicals. In addition, hydrogen radicals (H•) were also observed, which were not detected in previous studies. They were most likely generated by photochemical decomposition of semiquinone radicals. The irradiation of mixtures of benzoquinone and levoglucosan led to substantial formation of carbon- and oxygen-centered organic radicals, which became prominent in mixtures with a higher fraction of levoglucosan. High-resolution mass spectrometry permitted direct observation of BMPO-radical adducts and demonstrated the formation of •OH, semiquinone radicals, and organic radicals derived from oxidation of benzoquinone and levoglucosan. Mass spectrometry also detected superoxide radical adducts (BMPO-OOH) that did not appear in the EPR spectra. Kinetic modeling of the processes in the irradiated mixtures successfully reproduced the time evolution of the observed formation of the BMPO adducts of •OH and H• observed with EPR. The model was then applied to describe photochemical processes that would occur in mixtures of benzoquinone and levoglucosan in the absence of BMPO, predicting the generation of HO2• due to the reaction of H• with dissolved oxygen. These results imply that photoirradiation of aerosols containing photosensitizers induces ROS formation and secondary radical chemistry to drive photochemical aging of BBOA in the atmosphere