Papers by Keyword: Compound

Abstract: The article presents the results of studies of the chemical stability of solidified radioactive waste with alkali cement through long-term leaching. Efficiency of application of alkaline slag Portland cement type LCEM IV as a matrix for reliable chemical and physical binding of caesium ions in the compound for long-term burial we confirmed. Modification of alkaline cement by additions of magnetite from 5 to 8.3% and zeolite in the amount from 4.2 to 5% promotes additional sorption of caesium ions in solidification products of alkaline matrix at maximum content of radioactive waste up to 17.5%. It they noted that the maximum values of sorption capacity of compounds (from 42000 to 68000 ml/g) we observed on the 14th day of the leaching process. They are characteristic for compounds containing magnetite from 5 to 8.3%, zeolite - from 4.2 to 7.5% and radioactive waste from 10 to 15%. It is shown that on the first day of leaching the highest rate (8.35E-02 g/сm²day) is characterised by compositions containing magnetite from 5 to 8.3%, zeolite from 4.2 to 5% and radioactive waste from 15 to 17.5%. At 56 days of the test, the leaching rate decreases exponentially to values of 3.45E-05 to 9.62E-06 g/сm²day. Characteristic of compounds, magnetite and zeolite up to 5% and radioactive waste 17.5%.

Abstract: The purpose of this work is to improve the production technology of biodegradable hybrid compositions based on low-density polyethylene with thermoplastic starch and new plasticizer–distilled monoglyceride and determination of the composition effect on mechanical properties. Starch was plasticized with a mixture of glycerol and distilled monoglycerides, instead of the known sorbitol. This article describes methods for producing biodegradable hybrid composite films based on polyethylene and thermoplastic starches (corn, pea and rice) with a mass ratio of components, respectively, 40:60÷60:40 and their mechanical properties. Properties and structure of composite films are studied using test methods, rheological parameters, optical microscopy, and differential scanning calorimetry. The advantages of using monoglycerides as a plasticizer in thermoplastic starch/ polyethylene compositions have been demonstrated. Composites obtained using distilled monoglycerides and thermoplastic corn, pea and rice starch have been characterized by 62-81% higher values of critical stress and 62-93% elongation at rupture, compared with BHC containing sorbitol. The thickness of biodegradable hybrid composite films with monoglycerides is 55-86% less than that of films containing sorbitol in composition of thermoplastic starch. Higher elongation values at rupture and lower film thickness will ensure more effective destruction in environment and more cost-efficient use in packaging.

Abstract: The understanding of tire’s adherence with a rough surface is a common goal for several fields in the automotive sector. In fact, grip is synonym of safety and performance, playing a decisive role for braking distance and vehicle stability, fuel consumption, wear rate [1], noise generation and for the vehicle dynamics control system (e.g. ABS, TCS, AYC and other) [2]. This paper deals with tire tread grip experimental investigation and evaluation under different conditions that influence it during the sliding contact [3]. In this regard the test campaign involves the use of different tire compounds (in terms of viscoelastic characteristics), tested in several conditions: different contact pressure, sliding speed, temperature, sliding contact length and road surface. The test bench employed by the UniNa Vehicle Dynamic Research Group is an upgrade of the British Pendulum, an instrument for outdoor tribological tests on road sections. The principal sensors installed on the test bench are an encoder, for the evaluation of the sliding speed of the tire specimen, and a load cell, for the measurement of the force arising at tire/road interface in the longitudinal and vertical directions [4]. In fact, the grip shall be determined as the ratio of the longitudinal force and corresponding load on the tire. The paper's aim is the description of the experimental campaign after an accurate introduction on the test setup and an illustration of the equipment. Finally, the preliminary results and the methodologies used to process the acquired data are described.

Abstract: Mixing behaviors of the compounds filled with different reinforcing fillers were studied in correlation with compound and vulcanizate properties. Four filler systems were used including: 1) silica plus small amount of silane coupling agent; 2) carbon black; 3) pre-modified silica; and 4) silica+silane-carbon black mixed one. The results have shown that silica provides longer optimum cure time and shorter cure rate than carbon black due to accelerator adsorption on silica surface. In addition, owing to highly polar nature on silica surface the silica-based compounds show rather high viscosity, attributed to stronger filler-filler interaction as can be confirmed by Payne effect and reinforcement index. However, the commercial surface treatment or pre-modified form of silica shows superior properties than in-situ modification of silica by silane during mixing, while it gives comparable properties to carbon black-based compound. Tensile properties of vulcanizates show a good correlation with the basic properties of their compounds.

Abstract: The equilibrium alloys closed to Mg-Nd side in the Mg-rich corner of the Mg-Zn-Nd system at 400°C have been investigated by scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The binary solid solutions Mg₁₂Nd and Mg₃Nd with the solubility of Zn have been identified. The maximum solubility of Zn in Mg₁₂Nd is 4.8at%, and Mg₁₂Nd phase can be in equilibrium with Mg solid solution. However, only when the solubility range of Zn in 26at%~32.2at%, Mg₃Nd can be in two-phase equilibrium with Mg solid solution. As the results, two two-phase regions as Mg+Mg₁₂Nd and Mg+Mg₃Nd and a three-phase region as Mg+Mg₁₂Nd+Mg₃Nd in Mg-Nd-Zn ternary isothermal section at 400°C have been identified.

Abstract: This Paenibacillus polymyxa (P1) was fermented under the specific conditions and extracted the microbial flocculant (MBFP1) whose main components were polysaccharide. Compounded the MBFP1 and modified sepiolite fibers according to a certain mass ratio to make the microbial flocculant/sepiolite fibers water treatment materials (MBFSF), then analyzed their microstructure by SEM,and studied on the pollutants removal capacity in domestic sewage.The results show that,COD removal rate in domestic sewage can reach 97.2%,when pH=7.2 and the addition quantity of MBFSF is 15mg/L,in which the composite mass ratio of MBFP1 and sepiolite fibers is 5:2.Therefore,MBFSF has many advantages such as little dosage,high flocculating rate,fast settling velocity and no pollution,etc.

Abstract: Base on the thermodynamic calculation, CsI _(s) does not decompose to Cs _(s) and I _(s) at 600°C, either does not from I_2(g), CsO_(g), CsO_2(g), Cs₂O_(g), and Cs₂O_3(g). However during the experiment when CsI_(s) is heated above to 200 °C at 1 atm the purple vapor can clearly be obviated. The vapor should be I_2(g). It is because the incomplete boing of I^- which in the CsI compound is evaporation. In this paper, we are interesting in CsI properties during heating and calculation the Cs-I-O thermodynamic characterizations by the thermodynamic data books.

Abstract: With the method of solution polymerization, we prepared a high conversion rate and larger molecular weight acrylate copolymer. Using synthetic copolymer, low temperature stripping material was compounded with the proportional certain kinds of crosslinking agent, plasticizer, thickener and release agent, according to the certain reaction temperature and the loading sequence. The material mechanical properties, stripping, decontamination rate was tested and characterization. We got the strip materials meeting the low temperature environment. Finally, the influence factors of copolymerization reaction: the choice of solvent, dosage of initiator, monomer and the dosage was discussed. To achieve higher conversion rate and larger molecular weight acrylate copolymer, the method of solution polymerization was adopted in this study. Low temperature stripping material was compounded with synthetic copolymer, together with crosslinking agent, plasticizer, thickener and release agent in certain proportion, according to reaction temperature and the loading sequence. This material’s mechanical properties, stripping, decontamination rate were tested and characterizing definition was done. Results showed this strip material could meet the requirement of low temperature environment. Finally, the influence factors of copolymerization reaction were discussed, including the choice of solvent, dosage of initiator, monomer and the dosage.

Abstract: On the basis of experimental research about PVA fiber concrete, combined with the technology measures such as expansive belt, construction quality monitoring, the jointless design and construction is successfully carried out for an industry tank. The water storage test results showed that impervious performances can meet the requirements of specification and achieved desired effects.

Abstract: In this research, a study is made on the production and manufacturing process of the WPC unit member with 70% of wooden fiber contents, and described the productivity and durability of various modules based on factory-production-and-assembly-at-site system. Further, the study explained about the basic manufacturing process of eco-friendly highly filled extrusion-formed WPC, its unitification and material and mechanical characteristics.