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Background: Lignin played an important role in the establishment of coated fertilizers coating material as a substitute for petrochemical raw materials. However, so far, the lignin-based coated fertilizers was limited in only the poor slow-release performance. To achieve good slow-release performance of lignin-based coated fertilizers, hydrophilic of lignin need to be resolved to establish an green and better controllable lignin-based coated fertilizers. Results: In the study, a novel green double layer coating with lignin-based polyurethane (LPU) as the inner coating and epoxy resin (EP) as the outer coating was effectively constructed for coated urea. Fourier transform infrared spectra confirmed that lignin and polycaprolactone diol successfully reacted with Hexamethylene diisocyanate. The loss weight and water contact angle (WCA, 75.6–63.6°) of the LPUs decreased with the increased lignin content. The average particle hardness of the lignin-based double-layer coated urea (LDCU) first increased from 58.1 N (lignin of 30%) to 67.0 N (lignin of 60%), but then decreased to 62.3 N (lignin of 70%). The release longevity of the coated urea was closely related to the preparation parameters of the coating material. The optimal cumulative nutrient release rate (79.4%) of LDCU was obtained (lignin of 50%, –CNO/–OH molar ratios of 1.15, EP of 35%, and coating ratio of 5%). The aggregates of hydrone on the LDCU caused the dissolution and swelling of nutrients, and then the diffusion of nutrients through the concentration gradient. Conclusions: A though the nutrient release of the LDCUs was affected by many factors, the successful development of the LDCUs will help improve the rapid development of the coated fertilizer industry. [ABSTRACT FROM AUTHOR]

A kind of multiscale β-sialon grain-reinforced Al2O3 matrix composite ceramic tool material, named ASN, was prepared and studied. For the ASN, β-sialon (molecular formula: Si4Al2O2N6) was synthesized in situ by a hot-pressing and solid-solution reaction process. A total of six samples were prepared at varying sintering temperatures and holding times under vacuum conditions. The solid solution reaction mechanism of β-sialon, the phase composition, mechanical properties, microstructure, and strengthening and toughening mechanisms of the composite ASN were investigated. As a result, within the experimental parameters, an optimal ASN tool material was obtained under a pressure of 32 MPa and at a temperature of 1550 °C for 20 min. The tested mechanical properties of the optimal sample were as follows: flexural strength 997 ± 59 MPa, fracture toughness 6.4 ± 0.3 MPa·m1/2, Vickers hardness 18.2 ± 0.4 GPa, and relative density 98.1 ± 0.2%. According to crystal defect theory, the solid solution reaction mechanism of in-situ-synthesized β-sialon in an Al2O3 matrix involves a double mechanism of unequivalence (or hetero-valence) and interstitial filling. The multiscale β-sialon grains mainly consisted of four grains, which were elongated β-sialon grains with a diameter of 0.3–0.4 μm and an aspect ratio of 6–9, elongated β-sialon grains with a diameter of 70 nm and an aspect ratio of 10, β-sialon whiskers with a diameter of 0.2 μm and an aspect ratio of 12–15, and intragranular β-sialon whiskers with a diameter of 70 nm. The mechanical properties were improved due to strengthening and toughening mechanisms, such as mixed structure mode (intergranular and transgranular), elongated grain pullout, interface bonding, crack reflection, pinning, and bridging. [ABSTRACT FROM AUTHOR]

To investigate the nucleation behavior of ammonium sulphate, commonly used as a fertilizer, during cooling crystallization, polythermal methods have been used to determine the metastable zone widths (MSZWs) of ammonium sulphate in aqueous solution from the saturation temperature at 288.15 to 317.15 K under cooling rates of 6.0 to 30.0 K per hour. MSZWs increased with the increasing cooling rate and the saturation temperature. Based on classical nucleation theory, the nucleation potential model linked the MSZWs to the critical nucleation potential and pre-exponential factor. The MSZWs from one saturation temperature or with one cooling rate were used to predict the MSZWs with other saturation temperatures or with other cooling rates, by the nucleation potential model. The estimated MSZWs were compared with the experimental values. Further, according to the characteristics of the electrolyte solution, the supersaturation term in the nucleation potential model was modified by the activity coefficient. The estimated MSZWs showed improved accuracies and a tendency to be positively correlated with both the supersaturation temperature and cooling rate, which was consistent with the experimentally measured MSZWs. [ABSTRACT FROM AUTHOR]

The purpose of this work is to investigate the effect of the WC content on the surface characteristics and nanoindentation behaviors of WC/Ni-based composite laser-clad coatings. Four NiCrSiBC coatings with WC wt% of 30%, 40%, 50%, and 60%, respectively, were clad on carbon steel substrates using a laser. The morphologies and phase compositions of four clad coatings were comparatively observed. In addition, the hardness and elastic modulus values of the four coatings were measured and quantitatively calculated. As a result, with the increase in WC, the coating grains were more refined. Meanwhile, cracks and WC particle breakage occurred in the 50–60% WC coatings, whereas this was not found in the 30–40% WC coatings. When the WC content increased from 40% up to 50%, the coating hardness and elastic modulus significantly increased. However, a further increase in WC from 50% to 60% did not result in considerable improvement in coating quality but considerably worsened the coating's cracking behavior instead. Therefore, for WC/Ni-based composite coatings, a threshold exists for the WC content, and this value was 50% within the experimental scope of this study. [ABSTRACT FROM AUTHOR]

The compatibility of tetraethylammonium decahydrodecaborate (BHN) with some energetic components and inert materials of solid propellants was studied by DSC method, where glycidyl azide polymer (GAP), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitroamine (HMX), lead 3-nitro-1,2,4-triazol-5-onate (NTO-Pb), hexanitrohexaazaisowurtzitane (CL-20), 3,4-dinitrofurzanfuroxan (DNTF), N-guanylurea-dinitramide (GUDN), aluminum powder (Al, particle size=12.18 μm) and magnesium powder (Mg, particle size: 44-74 μm) were used as energetic components and polyoxytetramethylene-co-oxyethylene (PET), polyethylene glycol (PEG), addition product of hexamethylene diisocyanate and water (N-100), hydroxyl terminated polybutadiene (HTPB), cupric adipate (AD-Cu), cupric 2,4-dihydroxy-benzoate ( β-Cu), lead phthalate ( ϕ-Pb), carbon black (C. B.), aluminum oxide (Al2O3), 1,3-dimethyl-1,3-diphenyl urea (C2), di-2-ethylhexyl sebacate (DOS) and potassium perchlorate (KP), were used as inert materials. It was concluded that the binary systems of BHN with NTO-Pb, CL-20, aluminum powder, magnesium powder, PET, PEG, N-100, AD-Cu, β-Cu, ϕ-Pb, C. B., Al2O3, C2, DOS, and KP are compatible, and systems of BHN with GAP and HMX are slightly sensitive, and with RDX, DNTF, and GUDN are incompatible. The impact and friction sensitivity data of BHN and BHN in combination with the energetic materials under present study were obtained, and there was no consequential affiliation between sensitivity and compatibility. [ABSTRACT FROM AUTHOR]

An advanced hydrophobic lignin-based polyurethane coated urea (HLPCU) was successfully developed by synergy of carbon black (CB) and polysiloxane. In this work, CB and polysiloxane were employed to modify the liquefied lignin-based polyurethane (LLPU) and improve it's the hydrophobicity. The effects of polysiloxane contents and coating rates on the nutrient release of HLPCU were thoroughly investigated. The lignin was degraded into polyol with a low molecular weight. FT-IR, XPS and EDX results confirmed that polysiloxane was grafted to the LLPU. The water contact angle (WCA) of the HLPUs (89.39°–98.68°) gradually increased as the polysiloxane content rose (5 %–15 %). However, when the polysiloxane content further increased to 20 %, the WCA of the HLPUs rapidly declined (90.82°). A proper amount of polysiloxane molecules could increase thermo-physical properties of LLPU. The almost no pores were observed on the section micrograph of the HLPCU obtained by synergy of CB and polysiloxane. Synergy between CB and polysiloxane could significantly improve hydrophobicity and then enhance N release longevity of HLPCU (polysiloxane content of 15 %, coating rates of 7 %) up to 44 days. Compared to traditional urea, HLPCU could improve total N use efficiency the cabbage. The HLPCU and HLPCU85 treatments (15 % weight loss with fertilization) reduced the greenhouse effect of N 2 O, CO 2 and CH 4 and finally reduced GWP, especially for HLPCU85 treatment. This work will supply an advanced approach and process technology for progress of HLPCU and sustainable agriculture. • An advanced hydrophobic lignin-based polyurethane coated urea (HLPCU) was prepared. • Synergy between carbon black and polysiloxane improved nutrient release of HLPCU. • The coating material appeared excellent biodegradability in the soil. • The HLPCU improved the N use efficiency and reduced greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Background: Sepsis is one of the most common critical illnesses in intensive care unit (ICU) clinical practice. Intravenous infusion technology is an important method for life support. The commonly used deep vein indwelling is expensive, and the incidence of infection due to long-term placement is high. Ultrasound technology can guide clinical puncture operations in real time and greatly improve the success rate of puncture. In the present study, we aimed to explore the effect of ultrasound-guided external jugular vein puncture and catheterization in patients with sepsis., Methods: From December 2018 to December 2019, a total of 61 patients with sepsis from the ICU or neurology care unit (NCU) were included in the present study and were randomly divided into the experimental group (n=30) and control group (n=31). Ultrasound-guided indwelling cannula needle was used in the experimental group, and blind indwelling cannula needle was used in the control group. The success rate of puncture at first operation, indwelling complications (e.g., bleeding, redness, infection, poor infusion), and operation time of the 2 methods were compared., Results: A comparison of the patients in the control group with the experimental group indicated no significant differences in age, body mass index, sex, temperature, mean aortic pressure, sequential organ failure score, need for vasopressors, central venous pressure, leucocytes, hemoglobin, platelets, albumin, and mechanical ventilation (all P>0.05). The duration of ICU or NCU stay was 5 days in the experimental group compared with 7 days in the control group (P=0.009). Compared with the control group, the experimental group had shorter successful puncture time (4.0 vs. 6.0 min, P<0.001), higher first puncture success rate (93% vs. 71%, Ρ=0.023), and a lower incidence of complications (12.5% vs. 45.0%, P=0.001)., Conclusions: For patients with sepsis in ICU, ultrasound-guided puncture is superior to blind manual puncture.