Physiological acclimation strategies of riparian plants to environment change in the delta of the Tarim River, China

The occurrence and development of riparian forests, which were mainly dominated by mesophytes species related closely with surface water. Since there was no water discharged to the lower reaches of Tarim River in the past three decade years, the riparian forests degrade severely. The groundwater table, the saline content of the groundwater, as well as the content of free proline, soluble sugars, plant endogenous hormones (abscisic acid (ABA), and cytokinins (CTK)) of the leaves and relative rates of sap flow of the Populus euphratica Oliv. (arbor species), Tamarix ramosissima Ldb. (bush species), and Apocynum venetum L. (herb species) were monitored and analyzed at the lower reaches of the Tarim River in the study area where five positions on a transect were fixed at 100 m intervals along a sampling direction from riverbank to the sand dunes before and after water release. The physiological responses and acclimation strategies of three species to variations in water and salinity stress were discussed. It was found that A. venetum population recovered to groundwater table ranging from -1.73 to -3.56 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L; P. euphratica appeared to be more sensitive to the elevation of groundwater table than the A. venetum and T. ramosissima at groundwater table ranging from -5.08 to -5.80 m, and when exposed to saline content of the groundwater ranging from 42.17 to 49.55 m mol/L. T. ramosissima tended to be the best candidate species for reclamation in this hyper-arid area because it responded to groundwater table ranging from -1.73 to -7.05 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L. These results explained the distribution patterns of desert vegetation in the lower reaches of the Tarim River. Understanding the relationships among ecological factors variables, physiological response and acclimation strategies of plant individuals could provide guidance to sustainable management, reclamation and development of this and similar regions

Adhesive performance of camelina protein affected by extraction conditions

Citation: Qi, G., Li, N., Sun, X. S., & Wang, D. (2016). Adhesive performance of camelina protein affected by extraction conditions. Transactions of the Asabe, 59(3), 1083-1090. doi:10.13031/trans.59.11686Camelina protein (CP) adhesives were prepared from de-hulled camelina meal using alkaline solubilization (CP 8, CP 9, CP 10, CP 11, CP 12) and isolelectric precipitation. CP 12 had the highest protein yield with 46.22%, more than twice that of CP 8 (22.71%), indicating that extreme alkaline pH is necessary for high camelina protein solubility and protein yield. Extreme alkalinization resulted in severe molecular dissociation of camelina protein, as indicated by the appearance of a low molecular weight band (20 kDa). Compared to CP 8, CP 9, CP 10, and CP 11, CP 12 had a completely denatured protein structure with greater amounts of exposed functional groups, which is beneficial to the adhesion strength of CP 12. CP 12 with 9% sodium chloride treatment demonstrated optimum adhesion performance with dry and wet strengths of 4.36 and 1.36 MPa, respectively, compared to 3.37 and 1.05 MPa for CP 12 without sodium chloride treatment. © 2016 American Society of Agricultural and Biological Engineers

Tire pyrolysis char: Processes, properties, upgrading and applications

Waste tires are solid wastes with large annual output and with the potential for great harm to the environment. The pyrolysis of waste tires can recycle energy and produce reusable products. Although there are many reviews in the literature in regard to the pyrolysis characteristics of waste tires, no one paper focuses on reviewing and summarizing the tire char. This paper critically appraises the achievements of earlier reports and literature and assesses the current state-of-the-art for the production and application of tire char from waste tires. Initially, the thermal decomposition behavior of different tire rubbers is discussed and compared where it is shown that the different components of waste tire rubber have different thermal degradation characteristics. The influencing factors on the yield and quality of tire char are discussed and assessed in terms of different pyrolysis reactors and technologies, tire type and composition, and a range of pyrolysis process conditions. The composition of the waste tire and pyrolysis conditions are the main factors affecting the distribution of pyrolysis products. Pyrolysis technology and reactor equipment also have an effect on the distribution of pyrolysis products. The physical and chemical structural characteristics of tire char are critically reviewed in detail, including a comparison of the fundamental differences with commercial carbon black and modified tire char (physical activation and chemical activation). Finally, high-value application fields and developmental prospects of tire char are summarized. Through extensive literature review, a novel development was that tire char could be used as a source of gra-phene. The economic analysis of the various tire char applications should be one of the main research directions in the future. The keynote of this review is to promote intensification of waste tire recycling and treatment so that more tire char can be obtained from waste tire pyrolysis and thereby be reused in different applications to obtain more value.This project has received funding from the Science and Technology Exchange Project of China Ministry of Science and Technology (2021- 12-2) and Education Cooperation Project between China and Central Eastern European Countries (2021086) and Shaanxi Provincial Natural Science Foundation Research Program Shaanxi Coal Joint Funding (2019JLZ-12)

Characterization and Performance Assessment of BeiDou-2 and BeiDou-3 Satellite Group Delays

Based on one year of data, a comprehensive assessment of broadcast group delays and differential code biases (DCBs) from network solutions is presented for all open BeiDou signals. Daily DCB estimates exhibit a precision of 0.1 ns, which also places a limit on long-term variations of the satellite group delays. On the other hand, the estimated DCBs show a notable dependence on the employed receivers, which causes inconsistencies at the few-nanosecond level between BeiDou-2 and BeiDou-3 satellites. Systematic satellite-specific offsets can likewise be identified in broadcast group delay values and clock offsets. These constitute the dominant contribution of the signal-in-space range error (SISRE) budget and are a limiting factor for single point positioning and timing. Use of the modernized B1C/B2a signals is therefore recommended instead of B1I/B3I. This offers a SISRE reduction from about 0.6 m to 0.45 m and also improves the consistency of precise clock and bias products derived from heterogeneous receiver networks

Trajectory Optimization Based on Multi-Interval Mesh Refinement Method

In order to improve the optimization accuracy and convergence rate for trajectory optimization of the air-to-air missile, a multi-interval mesh refinement Radau pseudospectral method was introduced. This method made the mesh endpoints converge to the practical nonsmooth points and decreased the overall collocation points to improve convergence rate and computational efficiency. The trajectory was divided into four phases according to the working time of engine and handover of midcourse and terminal guidance, and then the optimization model was built. The multi-interval mesh refinement Radau pseudospectral method with different collocation points in each mesh interval was used to solve the trajectory optimization model. Moreover, this method was compared with traditional h method. Simulation results show that this method can decrease the dimensionality of nonlinear programming (NLP) problem and therefore improve the efficiency of pseudospectral methods for solving trajectory optimization problems

Oily sludge catalytic pyrolysis combined with fine particle removal using a Ni-ceramic membrane

Pyrolysis is one of the effective technology for oily sludge treatment and energy recovery. However, pyrolysis of oily sludge generates solid particles which are taken away from the reactor by gas, causing blockage in downstream equipment and reducing the quality of pyrolysis oil and gas. A study on the clean catalytic pyrolysis of oily sludge was carried out, by incorporating a ceramic membrane with or without Ni inside the pyrolysis reactor. It aims to investigate the effect of ceramic membrane on oily sludge pyrolysis and particulate removal. The yield of the pyrolysis gas produced from the reaction with Ni-ceramic membrane is 31.46 L/kg, while the recovery rate of pyrolysis oil is 48.21%. On the contrary, the yield of the pyrolysis gas produced from the reaction with blank ceramic membrane is 17.92 L/kg, while the recovery rate of pyrolysis oil is 62.63%. The particulate matter content in gas without and with Ni-ceramic membrane are 2.74 and 0.07 mg/L. The particulate matter content in oil without and with Ni-ceramic membrane are 3708.9 and 156.7 mg/L, respectively. Results indicated that the Ni catalyst loading on the ceramic membrane could improve the yield of the pyrolysis gas and remove the fine particles effectively. In addition, a long-time catalytic pyrolysis experiment was carried out, with the feeding speed of 4.17 g/min and the reaction temperature of 500 °C. It was found from the set conditions that the Ni-ceramic membrane could be used continuously for 420 min

Variable-Time-Domain Online Neighboring Optimal Trajectory Modification for Hypersonic Interceptors

The predicted impact point (PIP) of hypersonic interception changes continually; therefore the midcourse guidance law must have the ability of online trajectory optimization. In this paper, an online trajectory generation algorithm is designed based on neighboring optimal control (NOC) theory and improved indirect Radau pseudospectral method (IRPM). A trajectory optimization model is designed according to the features of operations in near space. Two-point boundary value problems (TPBVPs) are obtained based on NOC theory. The second-order linear form of transversality conditions is deduced backward to express the modifications of terminal states, costates, and flight time in terms of current state errors and terminal constraints modifications. By treating the current states and the optimal costates modifications as initial constraints and perturbations, the feedback control variables are obtained based on improved IRPM and nominal trajectory information. The simulation results show that when the changes of terminal constraints are not relatively large, this method can generate a modified trajectory effectively with high precision of terminal modifications. The design concept can provide a reference for the design of the online trajectory generation system of hypersonic vehicles

Biomass-based carbon materials for CO2 capture:A review

Carbon capture and sequestration technologies are essential to reduce CO2 emissions which are responsible for global warming. Carbon-based materials can play an important role in the reduction of CO2 emissions. These materials are normally produced from biomass through technologies such as pyrolysis and hydrothermal carbonization. The type of biomass feedstock and biomass conversion conditions can significantly affect the textual properties and surface chemistry of the carbon materials. Various modification methods such as material activation or N-doping can improve the properties of carbon materials to obtain better CO2 capture effects. This review summarizes recently reported research in the areas of using biomass-based materials for CO2 capture. The technologies of biomass conversion to carbon materials and modification of the carbon materials are critically analyzed. Meanwhile, the mechanisms of the CO2 capture process and research of different modification carbon materials for CO2 capture are also discussed. Finally, potential future research directions are suggested to promote carbon capture using biomass-based materials