FORMATION OF VANILLIN AND SYRINGALDEHYDE IN AN OXYGEN DELIGNIFICATION PROCESS

The formation of vanillin and syringaldehyde during an oxygen delignification process was evaluated. The cleavage of conjugated Cα-Cβ bonds in phenolic lignin caused by the attack of oxygen leads to the formation of aromatic aldehydes and ketones. The formation mechanism was confirmed by the organic compounds identified in the spent liquor by GC/MS. Additionally, the formation of aromatic aldehydes and ketones of hardwood, softwood, and grass was investigated. The results showed that the formed aromatic aldehydes and ketones were related to the units of lignin structure. Among the aromatic aldehydes and ketones present in the spent liquor from oxygen delignification, vanillin and syringaldehyde are of high content, making the spent liquor a potential resource for vanillin and syringaldehyde production

Smart Manufacturing Capability Maturity Model: Connotation, Feature And Trend

In March 2015, the Chinese government unveiled InternetPlus, an action plan expected to push forward the Chinese economy. The plan aims to integrate mobile Internet, cloud computing, big data, and the Internet of Things (IoT) with traditional industries to promote economic restructuring, improve people’s livelihoods, and even transform government and enterprises functions. However for the enterprises, how to evaluate the capability is still an unsolved issue. In this study, considering capability maturity theory and model existed, we summarized the concepts of smart manufacturing and relative research field, combined with the development trend of smart manufacturing and characteristics of the enterprise\u27s competition, a smart manufacturing capability maturity initial model with five levels and seven dimensions was defined. With this model, the connotation of smart manufacturing capability was unveiled and the model also provides reference for enterprises to assess and improve smart manufacturing capability

The PstI/RsaI and DraI polymorphisms of CYP2E1 and head and neck cancer risk: a meta-analysis based on 21 case-control studies

<p>Abstract</p> <p>Background</p> <p><it>CYP2E1 </it>encodes a member of the cytochrome P450 superfamily of enzymes which play a central role in activating and detoxifying many carcinogens and endogenous compounds thought to be involved in the development of cancer. The PstI/RsaI and DraI polymorphism are two of the most commonly studied polymorphisms of the gene for their association with risk of head and neck cancer, but the results are conflicting.</p> <p>Methods</p> <p>We performed a meta-analysis using 21 eligible case-control studies with a total of 4,951 patients and 6,071 controls to summarize the data on the association between the <it>CYP2E1 </it>PstI/RsaI and DraI polymorphism and head and neck cancer risk, especially by interacting with smoking or alcohol.</p> <p>Results</p> <p>Compared with the wild genotype, the OR was 1.96 (95% CI: 1.33-2.90) for PstI/RsaI and 1.56 (95% CI: 1.06-2.27) for DraI polymorphism respectively. When stratified according to ethnicity, the OR increased in the Asians for both polymorphisms (OR = 2.04, 95% CI: 1.32-3.15 for PstI/RsaI; OR = 2.04, 95% CI: 1.27-3.29 for DraI), suggesting that the risk is more pronounced in Asians.</p> <p>Conclusion</p> <p>Our meta-analysis suggests that individuals with the homozygote genotypes of PstI/RsaI or DraI polymorphism might be associated with an increased risk of head and neck cancer, especially in Asians.</p

An Enhanced Erasure Code-Based Security Mechanism for Cloud Storage

Cloud computing offers a wide range of luxuries, such as high performance, rapid elasticity, on-demand self-service, and low cost. However, data security continues to be a significant impediment in the promotion and popularization of cloud computing. To address the problem of data leakage caused by unreliable service providers and external cyber attacks, an enhanced erasure code-based security mechanism is proposed and elaborated in terms of four aspects: data encoding, data transmission, data placement, and data reconstruction, which ensure data security throughout the whole traversing into cloud storage. Based on the mechanism, we implement a secure cloud storage system (SCSS). The key design issues, including data division, construction of generator matrix, data encoding, fragment naming, and data decoding, are also described in detail. Finally, we conduct an analysis of data availability and security and performance evaluation. Experimental results and analysis demonstrate that SCSS achieves high availability, strong security, and excellent performance

An ex vivo preliminary investigation into the impact of parameters on tissue welding strength in small intestine mucosa-mucosa end-to-end anastomosis

Background: Tissue welding is an electrosurgical technique that can fuse tissue for small intestine anastomosis. However, limited knowledge exists on its application in mucosa-mucosa end-to-end anastomosis. This study investigates the effects of initial compression pressure, out-put power, and duration time on anastomosis strength ex vivo in mucosa-mucosa end-to-end anastomosis.Methods:Ex vivo porcine bowel segments were used to create 140 mucosa-mucosa end-to-end fusions. Different experimental parameters were employed for fusion, including initial com-pression pressure (50kPa–400 kPa), output power (90W, 110W, and 140W), and fusion time (5, 10, 15, 20 s). The fusion quality was measured by burst pressure and optical microscopes.Results: The best fusion quality was achieved with an initial compressive pressure between 200 and 250 kPa, an output power of 140W, and a fusion time of 15 s. However, an increase in output power and duration time resulted in a wider range of thermal damage. There was no significant difference between the burst pressure at 15 and 20 s (p &gt; 0.05). However, a substantial increase in thermal damage was observed with longer fusion times of 15 and 20 s (p &lt; 0.05).Conclusion: The best fusion quality for mucosa-mucosa end-to-end anastomosis ex vivo is achieved when the initial compressive pressure is between 200 and 250 kPa, the output power is approximately 140W, and the fusion time is approximately 15 s. These findings can serve as a valuable theoretical foundation and technical guidance for conducting animal experiments in vivo and subsequent tissue regeneration

Numerical and Experimental Study on Jet Trajectory and Fuel Concentration Distribution Characteristics of Kerosene Jet in Air Crossflow

The fuel concentration distribution in an afterburner is a critical factor that affects its ignition, flameout, stability, and combustion efficiency. Additionally, the trajectory of the fuel jet directly affects the distribution of the downstream fuel. Hence, this paper studied the factors that affect a jet’s trajectory and fuel concentration distribution through numerical calculations. The change law of the fuel jet trajectory under various parameters was studied, and the jet penetration depth change rate was analyzed. Moreover, the empirical formula of the spanwise distribution range of the liquid fuel in front of the stabilizer was fitted. Furthermore, this study investigated fuel concentration distribution experimentally in the afterburner under normal temperature and pressure. The paper obtained the variation law of fuel concentration in the spanwise and radial directions, and the proportion of the gaseous fuel in the flow section under the influence of different parameters. Additionally, the spatial distribution of the droplet concentration was obtained, revealing that it increased initially, and then decreased in the flow direction, reaching a peak at the end of the recirculation zone. In the radial direction, two concentration peaks were found in the boundary of the recirculation zone and in the main flow region