Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

High voltage electrical treatments can eco-efficiently promote the production of high added value peptides during chymotryptic hydrolysis of β-lactoglobulin

Chymotryptic hydrolysis of β-lactoglobulin (β-lg) leads to the release of a wide range of biofunctional peptides.However,the proteolysis of native β-lg is limited due to its compact globular structure,thus ending with low yields of peptides.Whereas our previous study showed that eco-efficient High Voltage Electric Treatments (HVET),namely Pulsed Electric Fields (PEF) and Electric Arc (ARC),of β-lg substantially improved its enzymatic hydrolysis,no information regarding the nature of released peptides is available up to date.Hence,the time-dependent release of peptides and the dynamics of this release were discussed in the current study.Chromatographic analysis of the final hydrolysates showed that chymotrypsinolysis of HVET samples released 19% more peptides with higher concentration than the native and preheated ones.Furthermore,1-min HVET were found to be more efficient than 10-min ones as they led to the release of bioactive peptides (even without chymotrypsin) with higher eco-efficiency scores.

EFFECT OF SOLUTION TREATMENT IN AN ELECTRIC FIELD ON MECHANICAL PROPERTIES AND MICROSTRUCTURE OF 2091 Al—Li ALLOY

Solution treatment of 20% Al-Li alloy in an electric field has been studied. The results show that it increases the solubility of elements and accelerates the nucleation of T1-phase and promotes the formation of the precipitation free zones(PFZ), and increases the strength and decreases the plasticity of the alloy.

Effect of homogenization treatment in electric field on microstructure and properties of 1420 Al-Li alloy

In comparison with the homogenization treatment without an electric field prior to the same solid solution and aging treatment, the homogenization treatment in an electric field increases the hardness and strength of 1420 Al Li alloy, but somewhat decreases the elongation of the alloy. Moreover, the elongation of the alloy increases with the homogenization temperature in an electric field increasing. TEM observation showed that the homogenization treatment in an electric field can accelerate the dissolution of the coarse particles of second phase on the grain boundary as well as make δ′phase precipitated in subsequent aging process finer and more numerous.

Effects of O_2 Plasma Treatment on the Chemical and Electric Properties of Low-k SiOF Films

With the progress of ULSI technology, materials with low dielectric constant are required to replace Si02 film as the interlayer to scale down the interconnection delay. Fluorinated Si oxide thin films (SiOF) are a promising material for the low dielectric constant and the process compatibility in existing technology. However, SiOF films are liable to absorb moisture when exposed to air. By treating the SiOF films with O2 plasma, it was found that the moisture resistibility of SiOF films was remarkably improved. The mechanism of the improvement in stability of dielectric constant was investigated. The results show that: 1) F atoms dissociated from the films and the bond angle of Si-O-Si decreased. 2) The plasma treatment enhanced the strength of Si-F bonds by removing unstable =SiF2 structures in the films. Resistibility of SiOF films in moisture was improved.

EFFECT OF HOMOGENIZATION TREATMENT UNDER AN ELECTRIC FIELD ON T_1 DISTRIBUTION AND MECHANICAL PROPERTIES OF 2091 Al－Li ALLOY

Homogenization treatment under an electric field increases the distributive homogeneity of the T1 precipitation and improves the yield strength of 2091 Al-Li alloy.

Effects of electric pulse on microstructure of Al-Si alloy in liquid and solid states

In order to investigate the change in liquid microstructure of Al-Si alloytreated by electric pulse (EP), X-ray diffraction tests with liquid Al-Si alloy and ZL109 alloytreated or not by EP were carried out. The results show that the number of Al-Si atomic clustersdecreases and that of Al-Al and Si-Si atomic clusters increases for the treated samples. The testswith ZL109 alloy indicate that a large amount of primary crystal Si appears in the solidifiedmicrostructure after treated by EP. It is found that EP can change the microstructure of liquidmetal by affecting the probability of electrons appearing in different atoms (Al and Si) in theliquid metal. The combining force of different atoms decreases relatively, and that of the sameatoms increases, which is the main reason of reducing the atomic cluster with different atoms(Al-Si) and increasing the atomic cluster with the same atoms (Al-Al, Si-Si). The increasing of theatomic cluster with the same atom cluster resulted in the increasing of Si activity and the higherpoint of eutectics in the phase diagram. It makes a lot of primary silicon appeared in ZL109 alloy.

TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION FOR TREATMENT OF SPINAL SPASTICITY

Thirty-two patients with spinally originated muscle spasticity were treated with a transcutaneous electrical nerve

Non-Invasive Treatment to Grade 1 Essential Hypertension by Percutaneous Laser and Electric Pulse to Acupoint with Music:A Randomized Controlled Trial

Objective： To study a non-drug therapy for hypertension disease by combining percutaneous laser and electric pulse stimulation to acupoint with music, and to test the efficiency of the combining treatment to grade 1 essential hypertension. Methods： A total of 174 patients with grade 1 essential hypertension were randomly assigned to 3 groups with a random number table after Chinese medicine（CM） syndrome differentiation： the photoelectric and musical treatment group（Group 1, with a self-developed multi-mode audio frequency pulse photoelectric therapeutic apparatus）, acupuncture group（Group 2）, and oral placebo group（Group 3）, 58 cases per group. The curative effect of each group was evaluated by the changes of blood pressure and CM syndrome integral before and after treatment. Results： Compared with Group 3, there were significant decrease of blood pressure and CM syndrome integral in Group 1 and Group 2（P〈0.01）. Compared with Group 2, Group 1 showed the highest decrease in systolic pressure（P〈0.017）. The total effective rate of anti-hypertension in Group 1（91.38%, 53/58） was significantly higher than that in Group 2（74.13%, 43/58） and Group 3（18.97%, 11/58, P〈0.05 or P〈0.01）; and that in Group 2 was also significantly higher than that in Group 3（P〈0.01）. There were significant difference in the total effective rate of CM syndrome integral in both Group 1（93.10%, 54/58） and Group 2（84.48%, 49/58） as compared with Group 3（17.24%, 10/58, P〈0.01）, while there was no significant difference between Group 1 and Group 2（P〉0.05）. Conclusions： The multi-mode audio frequency pulse photoelectric therapeutic apparatus, combining music, laser and electric pulse stimulation, is clinically useful for grade 1 essential hypertension. This ＂three in one＂ therapy method is non-invasive, easy and simple to handle. It is expected to be popularized as a new alternative treatment.

Performance and recent improvement in microbial fuel cells for simultaneous carbon and nitrogen removal: A review

Microbial fuel cells（MFCs） have become a promising technology for wastewater treatment accompanying electricity generation. Carbon and nitrogen removal can be achieved by utilizing the electron transfer between the anode and cathode in an MFC. However,large-scale power production and high removal efficiency must be achieved at a low cost to make MFCs practical and economically competitive in the future. This article reviews the principles, feasibility and bottlenecks of MFCs for simultaneous carbon and nitrogen removal, the recent advances and prospective strategies for performance improvement, as well as the involved microbes and electron transfer mechanisms.

Effect of grain refinement on cutting force of difficult-to-cut metals in ultra-precision machining

The nickel-based superalloy Inconel 718 is treated with Coupled Ultrasonic and Electric Pulse Treatment(CUEPT),and the surface grain is refined from the average size of 9550.0 nm to287.9,216.3,150.5,126.3,25.8 nm by different effective treatment currents,respectively.The ultraprecision turning experiments are carried out on the processed workpiece after CUEPT.The experimental results show that the average cutting force increases with the decrease of surface grain size.Moreover,a mathematical model that can describe the relationship between grain size and cutting force is established,and the calculated results match the experimental results well.The calculated results also indicate that the variation of cutting force caused by the same variation of grain size decreases as the degree of grain refinement increases.Finally,the influence mechanism of grain refinement on cutting force is analyzed.The improvement of stability of grain boundaries and the increase of number of grain boundaries cause the increase of cutting force after grain refinement.