Papers by Keyword: Evaluation

Abstract: A novel polycarboxylate superplasticizer (PCE) with energy saving preparation was elaborately designed and synthesized by using acrylic acid (AA), hydroxypropyl acrylate (HPA) and isopentenyl polyethylene glycol (IPEG) as monomers. To investigate the effects of the preparation method on the effectiveness of PCE, the PCEs were prepared from energy-saving method and common method respectively, and the hydration heat evolutions of the cement pastes containing these PCEs were comparatively probed. Furthermore, the working mechanisms of the PCEs by different preparations were identified via adsorption behavior, adsorption kinetic and Zeta potential of the PCE on cement surfaces. The results showed that, this novel PCE prepared in an energy saving manner can significantly prolong the hydration process and present a stronger adsorption capacity. In addition, the adsorption of this PCE on cement surface exhibited a characteristic of pseudo first order kinetic equation model. The evaluation in energy conservation showed that, this energy saving preparation can save 1.548×10⁴ kJ per 10 ton production. The aim of this study is to provide a new avenue to synthesize a PCE with economical method which achieves energy-saving preparation. Due to the indispensable application in construction industry, the innovations from this study contribute to the low energy-consumption production and high eco-effectiveness of the novel PCE, which has potential applications in low-emission building materials.

Abstract: This study aimed to determine the chemical composition and gas production based on fermentation in the rumen of nine types of forage tropical feed commonly used, named mahogany (Swietenia mahagoni L. Jacq.), tayuman (Bauhinia purpurea), bamboo (Bambusa arundinaceae), canary (Canarium) indicum L.), tea (Camellia sinensis), ketapang (Terminalia catapa L.), lamtoro (Leucaena leucocephala), tehtehan (Duranta repens), and turi (Sesbania grandiflora). Measurement of gas production in vitro was carried out at 7 observation points of hours (2, 4, 8, 16, 36, 48, 72). Tannin activity was measured using measurements of gas production divided into three groups with modified levels of polyethylene glycol (PEG), i.e., samples without PEG (P1); sample + PEG in the amount of 200 mgDM (P2); and PEG + samples of tannins contained in each forage based on literature studies (P3). The total content of tannin varied between 0.20 - 13.80%. The most optimal measurement of gas production was in the sample given PEG of 200mg/kg with a significant difference (P<0.05). From the result, it was found that the higher the tannin content, the lower of gas produced. The addition of PEG was proven to be able to optimize the digestibility value seen from the higher gas production.

Abstract: Fracturing proppant is an important material for hydraulic fracturing, and its performancehas an important impact on the fracturing effect and the fracturing life of oil and gas wells. On thepremise of satisfying the reservoir reconstruction requirement, optimizing the proppant with the besteconomic benefit can reduce the cost of the fracturing operation. The flow conductivity and brokenrate of common proppants are tested to obtain the performance boundaries. Based on the proppantevaluation, according to the selection method, the optimal proppant type for different formationpressures can be selected to maximize economic benefits.

Abstract: Phosphorus scale inhibitor is a kind of agent which can disperse insoluble inorganic salts in water, prevent or interfere with the precipitation and scaling of insoluble inorganic salts on metal surface, and maintain better heat transfer effect of metal equipment. Sodium triethylenetetramine hexamethylphosphonate (TETHMPS) and tetraethylenepentamine heptagon methylene phosphonic (TEPHMPS) were prepared by one-step synthesis method. The effects of temperature, concentration and mixing ratio on scale inhibition were investigated. The results showed that as the concentration of TETHMPS and TEPHMPS increases, the scale inhibition rate increases. At the same temperature, compared with TETHMPS, TEPHMPS has better scale inhibition performance, and the maximum scale inhibition rate can reach 93.59%. The scale inhibition rate of the synthesized scale inhibitor at 80 °C is better than that at 60 °C. The scale inhibition performance of the compound scale inhibitor is better than that of the single scale inhibitor, showing an ideal synergistic effect. When the concentration is 60 mg/L, the scale inhibition rate of TETHMPS is 94.26%, TEPHMPS is 94.55%, and the scale inhibition rate is above 91%.

Abstract: Compared with inorganic phosphonates, organic phosphonates have better chemical stability in water treatment, and are not easy to hydrolyze in higher temperature and wider pH range. In this paper, a one-step synthesis method of ethylene diamine tetra (methylene phosphonic acid) sodium (EDTMPS) and methylene phosphonic acid (DTPMPA) were studied. A new phosphate scale inhibitor was prepared and its scale inhibition performance was evaluated. The results showed that the scale inhibition rate increased with the increase of the concentration of synthetic products (EDTMPS, DTPMPA). At the same concentration, compared with DTPMPA, EDTMPS has better scale inhibition performance, and the maximum scale inhibition rate can reach 96.85%. The scale inhibition performance of composite scale inhibitor is better than that of single scale inhibitor, and the scale inhibition rate of the synthesized products can reach more than 90% after compounding. And inhibitory mechanism has been proposed: Because phosphonates effectively control the rate of nucleation. In addition, polyphosphonates can chelate Ca²⁺, Mg²⁺ plasma to form monocyclic or bicyclic chelates. This will destroy the normal growth process of calcium carbonate and other crystals, thus preventing the formation of calcium carbonate scale.

Abstract: Depending on the type of garment to be designed, designers, developers, and retailers are aware of and put forward certain requirements for the implementation of an appropriate level of quality. But ultimately the consumer is the one who decides whether the product meets his individual requirements. There are many different standardized textile testing methods, as well as various subjective assessment methods for hand feel and wearing comfort occurs. The observations that the analysis of a product has to be complex has become increasingly widespread. The aim of the research is to formalize and practically use the conceptual method of drape, appearance and comfort measurements.

Abstract: Leakage accidents often occur at the bolted flange joints, which are widely used in the petro-chemical plant. This is mainly resulted by the reduction of bolt force during operation. Therefore, bolt force is very important for sealing performance of the joints in service. Based on the leakage rate parameter, the relationship between the bolt force and gasket stress was derived. Moreover, the leakage rate model was established on the basis of bolt force. With this model, the leakage rate can be directly calculated through the bolt force, and the sealing performance can be evaluated. In order to verify this model, corresponding experiments have been performed. It shows that with the internal pressure increasing, the bolt force increases and the gasket stress reduces. There exists a monotonic relationship between the bolt force and gasket stress. The theoretical gasket stress value corresponds well with the experimental value. The calculated leakage rates for the joints also agree well with the experimental value. Then, it is feasible to evaluate the sealing performance for the bolted flange joints based on the bolt force.

Abstract: The manufacturing process gives cast iron castings properties which are dependent on component design, metallurgy and casting method. Factors as local wall thickness influences the coarseness and type of microstructure and the material will have local properties depending on the local metallurgical and thermal history. The stress/strain behaviour of cast products at load are typically performed by using a tensile test machine.

Abstract: This paper presents the simplified method of efficiency evaluation of surface protection products for concrete elements. This evaluation method was designed to consist of as few testing procedures as possible and to use as few specimens as well. Several testing processes most of which were based on the European technical standards were used to compare five commercially available products. Those comparisons served to assess whether the chosen method has sufficient informative value and does not require a disproportionate amount of time and money. The main examined properties were impact on color and reflectivity of the original surface, durability of the coating in extreme weather conditions, wettability of the surface and amount of labor needed for its maintenance. All of these experiments were optimized so that they could be performed on one type of specimen.

Abstract: Economic evaluation of losses conditioned by disposing radioactive wastes of the “Prydniprovskyi Chemical Plant” Production Association on the territory of Kamianske and surrounding areas of the Dnipropetrovsk region is performed. While analysing losses, four uniform groups of expenses and losses were distinguished which include: expenses on protecting and monitoring measures, expenses on remediation measures, social orientation expenses and expenses related to waste disposal. It is shown that expenses on protecting and monitoring radioactive waste storages prevail.