Search

Oil-contaminated wastewater threatens our environment and health thus novel membrane materials with low or nonfouling properties are an immediate need for oily wastewater treatment in a cost-effective and environmentally friendly manner. In this study, three types of amphiphilic random, gradient, and block copolymers with similar molecular weights and chemical compositions, based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate (TFOA), were synthesized by the reversible addition-fragmentation chain transfer (RAFT) method. The amphiphilic Poly(ether sulfone) membranes were then fabricated by blending with these copolymers via a facile coupled process of nonsolvent induced phase separation and surface segregation. Accompanying the phase inversion process of polymer matrix, the hydrophilic and hydrophobic segments in the amphiphilic modifiers would migrate and immobilize onto the membrane surfaces. This surface segregation process leaded to a chemical heterogeneous membrane surface comprising both hydrophilic PEGMA and low surface energy PTFOA brushes, which was confirmed by X-ray photoelectron spectroscopy (XPS) and surface wettability analyses. Oil-in-water emulsion filtration test of the membranes displayed a lower permeate flux decline and a higher flux recovery (as high as 99.8%), establishing their considerably elevated antifouling properties. Additionally, cyclic oil/water separation and long-term underwater immersion tests demonstrated that the as-prepared membranes modified by these amphiphilic additives possessed excellent antifouling stabilities. © 2016 American Institute of Chemical Engineers AIChE J, 63: 739-750, 2017 [ABSTRACT FROM AUTHOR]

ABSTRACT A series of gradient fluorinated copolymers with a broad variation of the monomer units in the polymer chain were synthesized via semibatch CPDB-mediated RAFT miniemulsion polymerization technique. In the presence of RAFT agent 2-cyanoprop-2-yl dithiobenzoate (CPDB), the copolymerization of BMA and FMA in miniemulsion exhibited typical features of a controlled molecular weights and narrow polydispersities. The macromolecular structure and thermal behavior of the synthesized fluorinated copolymers were investigated in detail. The DSC analyses show that the gradient copolymers showed a unique thermal behavior with broad range of transition temperature. It was also confirmed that the fluorinated gradient copolymer exhibited obvious surface segregation structure and ultra-low surface energy between 16.8 and 20.3 mN/m. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42936. [ABSTRACT FROM AUTHOR]

The deepwater long-line rope aquaculture facility (the raft system) belongs to a raft mariculture method which is mainly composed of buoys, main rope, aquaculture net cages, mooring ropes and anchor stakes embedded into seabed. The buoys are connected with the main rope by rope, the main rope is connected to stake anchor by mooring rope, and the aquaculture net cage is hung on the main rope. The buoyancy of raft system is provided by buoys and the structure stability is ensured by the mooring force from anchor stakes embedded into seabed. The facility stays in deep-open waters with winds, waves, urgent flow, and is influenced by complex sea environment. The raft system will move and deform in the action of environmental load. When the tension force is over the strength of mooring rope or the maximum mooring anchorage force provided by the anchor stake, or the transversal displacement of the main rope is oversize, the raft system will become less stable. The safety and stability of the aquaculture facility will directly affect the success or failure of the whole aquaculture production. Therefore, it's certainly worth researching on the force and motion of the raft system considering the effect of ocean waves and current for structure design, and furthermore analyzing the raft system's wind resistance ability to provide reference for the parameter design of the raft system. In this paper, based on the finite element method, the stress characteristic and deforming of deepwater long-line rope aquaculture facility system were analyzed to establish finite element model equation. For the components in the raft system (buoy, cage, rope) belong to small scale marine structures, the fluent loads were calculated by Morison method, in which in order to calculate different grades of wave, the large wave height should be considered and the nonlinear wave force cannot be ignored, and the two order Stokes wave theory was employed to calculate the speed and acceleration of water particle. Broyden iteration method was used to solve the finite element equation of aquaculture facility system, and then the maximum tensions of the mooring rope in the system in different heights (1-14 m) of sea wave were calculated and compared to its break strength and mooring force of anchoring pile for evaluating wind resistance ability of the aquaculture facility system. As an instance, the wind resistance abilities of deepwater long-line rope aquaculture facilities erected in 30-meter deep sea waters of Zhangzidao aquaculture sea area were analyzed. The result showed that maximum tension of mooring rope was 78.8 kN, the maximum transverse displacement of the raft system was 18.5 m and the wind resistance abilities were at 6-7 level of sea wave (6 m wave height) with 1.5 m/s current. Respectively the actual measured data were 72.7 kN and 16.9 m. By comparison, the values of calculation are well consistent with actual measured ones. By further experimental verification, the analysis model and method can be referenced for practical engineering design of deepwater long-line rope aquaculture facility. [ABSTRACT FROM AUTHOR]

By analyzing and investigating the condition of raft culture working for Patinopecten yessoensis and the harvest mode of artificial raft suspended culture in Dalian Zhangzidao, a new type of high efficiency and energy-saving raft culture working mode and devices for Patinopecten yessoensis were upgraded reconstruction. In order to prove that working mode and device structure are reasonable, comparative tests were executed in the sea area of raft suspended culture in Dalian Zhangzidao. The test was divided into two stages, with test sites in Da Hao island, Da Lian island, Xiao Hao island, and Zhang Zi island. For the phase I test, four trial sites were respectively equipped with three original floating raft culture boats, three floating raft culture boats of first stage reconstruction, and two material transport boats (the length, width and depth of the original floating raft culture boats and first stage reconstruction floating raft culture boats are 8 m, 2.4 m and 0.5 m respectively; the loading capacity is limited in order to meet work requirements with one material transport boat respectively equipped with three floating raft culture boats). Tests were based on actual production situations, and lasted 44 d, working 8 h per day. From November 2nd, to November 23rd, 2011 is the scallop harvest working test. From July 30th, to August 20th, 2012 is the scallop grading working test. For the phase II test, four trial sites were respectively equipped with three floating raft culture boats of second stage reconstruction, three floating raft culture boats of first stage reconstruction, and one material transport boat (the length, width, and depth of the floating raft culture boats of second stage reconstruction are 12 m, 3.3 m, and 0.7 m respectively; the loading capacity meet work requirements, so floating raft culture boats of second stage reconstruction didn't need a material transport boat). The test lasted 44 d, working 8 h per day. From November 1st to November 22nd, 2012 is the scallop harvest working test. From August 1st to August 22nd, 2013 is the scallop grading working test. At the end of testing per day, the amounts of pulling cage and consumption costs of energy were calculated. The results show that the upgraded reconstruction raft culture working boats on the first stage, which consisted of the installed pull stalk rope device, pull cage device, shake cage device, screen device, and toothed pulley slide stalk rope device, relying solely on human work operation mode was changed to mechanical work mode, and the amounts of pulling cage were increased by 56.01% of single-ship per day. Because the installed electric equipments and the rate of the starting diesel engine were declined, energy consumption costs were reduced by 13.95%. The second stage reconstruction raft culture working boats were based on retaining electric equipments and the length, width, and depth were increased from 8 m to 12 m, from 2.4 m to 3.3 m, and from 0.5 m to 0.7 m respectively. The amount of pulling cages were respectively increased by 31.69% and 105% than floating raft culture boats of first stage reconstruction and the original floating raft culture boats. Energy consumption costs of the second reconstruction raft culture working boats are an insignificant difference with the first reconstruction raft culture working boats and reduced by 14.12% of the original floating raft culture boats. The second stage reconstruction raft culture working mode saved 10.8 thousand yuan per year more than the original floating raft culture working mode. In conclusion, the reconstruction raft culture working boat improves working efficiency, and reduces energy consumption. It has a good prospect in application. [ABSTRACT FROM AUTHOR]

Electromagnetic interference (EMI) is a pervasive and harmful phenomenon in modern society that affects the functionality and reliability of electronic devices and poses a threat to human health. To address this issue, EMI-shielding materials with high absorption performance have attracted considerable attention. Among various candidates, two-dimensional MXenes are promising materials for EMI shielding due to their high conductivity and tunable surface chemistry. Moreover, by incorporating magnetic and conductive fillers into MXene/polymer composites, the EMI shielding performance can be further improved through structural design and impedance matching. Herein, we provide a comprehensive review of the recent progress in MXene/polymer composites for absorption-dominated EMI shielding applications. We summarize the fabrication methods and EMI shielding mechanisms of different composite structures, such as homogeneous, multilayer, segregated, porous, and hybrid structures. We also analyze the advantages and disadvantages of these structures in terms of EMI shielding effectiveness and the absorption ratio. Furthermore, we discuss the roles of magnetic and conductive fillers in modulating the electrical properties and EMI shielding performance of the composites. We also introduce the methods for evaluating the EMI shielding performance of the materials and emphasize the electromagnetic parameters and challenges. Finally, we provide insights and suggestions for the future development of MXene/polymer composites for EMI shielding applications., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Human DNA sequencing protocols have revolutionized human biology, biomedical science, and clinical practice, but still have very important limitations. One limitation is that most protocols do not separate or assemble (i.e., "phase") the nucleotide content of each of the maternally and paternally derived chromosomal homologs making up the 22 autosomal pairs and the chromosomal pair making up the pseudo-autosomal region of the sex chromosomes. This has led to a dearth of studies and a consequent underappreciation of many phenomena of fundamental importance to basic and clinical genomic science. We discuss a few protocols for obtaining phase information as well as their limitations, including those that could be used in tumor phasing settings. We then describe a number of biological and clinical phenomena that require phase information. These include phenomena that require precise knowledge of the nucleotide sequence in a chromosomal segment from germline or somatic cells, such as DNA binding events, and insight into unique cis vs. trans-acting functionally impactful variant combinations-for example, variants implicated in a phenotype governed by compound heterozygosity. In addition, we also comment on the need for reliable and consensus-based diploid-context computational workflows for variant identification as well as the need for laboratory-based functional verification strategies for validating cis vs. trans effects of variant combinations. We also briefly describe available resources, example studies, as well as areas of further research, and ultimately argue that the science behind the study of human diploidy, referred to as "diplomics," which will be enabled by nucleotide-level resolution of phased genomes, is a logical next step in the analysis of human genome biology., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

High durability, low cost, and superior anti-icing and active deicing multifunctional surface coatings, especially in the extreme environment, are highly desired to inhibit and/or eliminate the detriment of icing in many fields, such as automobile, aerospace, and power transmission. Herein, we first report a facile and versatile strategy to prepare novel slippery polyols-infused porous surfaces (SPIPS's) with the inexpensive polyols as the lubricant liquids. These SPIPS's are fabricated by a spray-coating approach based on amino-modified magnetic Fe 3 O 4 nanoparticles (MNP@NH 2 ) and amphiphilic P(poly(ethylene glycol) methyl ether methacrylate- co-glycidyl methacrylate) copolymer covalent cross-linked hybrids, followed by infusion with various polyols. The as-prepared surface exhibits excellent antifrosting property, that is, it can greatly postpone frost formation as long as 2700 s at -18 °C. Meanwhile, differential scanning calorimetry results clearly demonstrate that SPIPS's show a remarkable freezing point depression capacity and the crystallization point of water can be decreased as low as -36.8 °C. The SPIPS also displays an extremely low ice adhesion strength (0.1 kPa) due to its unique surface characteristics. Moreover, outstanding active thermal deicing property is achieved for these slippery surfaces because of intrinsically photothermal effect of magnetic Fe 3 O 4 nanoparticle. Hence, these results indicate that this kind of multifunctional bioinspired slippery surface, with superb stability, good cost effectiveness, and easy fabrication, can be used as a promising candidate for anti-icing and deicing applications.