Failure analysis of multiphase flow corrosion–erosion with three-way injecting water pipe

Water injection is an essential component in a reaction effluent air cooler (REAC) system because its primary function is to dissolve the generated ammonium salt, which leads to deposition or blockage accidents. A damage incident in a three-way pipe made of carbon steel under the multiphase flow field was investigated. The failure analysis was performed by means of scanning electron microscope (SEM) inspection and computational fluid dynamics (CFD) simulation. CFD results show that a large velocity gradient exists near the area of 5–12d at the bottom of the main pipe. This gradient results in a region of low flow velocity, high wall shear stress, and high turbulent kinetic energy. The flow state becomes very chaotic, and the non-uniformity coefficient of velocity is high. The corrosive medium (NH₄Cl or H₂S) dissolving in water increases the causticity of fluid medium and aggravates the flow corrosion. The high risk area from the CFD simulation coincides with the breakage area of the three-way pipe on the spot. This failure incident is attributed to the flow corrosion–erosion.     

Structural analysis of the interrelationship between economic activities and water pollution in Vietnam in the period of 2000–2011

Clean Technologies and Environmental Policy - Rapid economic growth and poor waste management have left Vietnam with severe water pollution problems. It is thus important to develop a model to...     

Structural analysis of phases and heterophase interfaces in the zirconium–boron system

The Zr–ZrB2 eutectic, a model system for metal–boride interfaces, was prepared by r.f. induction melting from high-purity zirconium ingots and zirconium diboride powders. At the eutectic composition and depending on the cooling rate, the formation of either the ZrB phase or a Zr(B) solid solution has been observed in addition to the expected compound Zr and ZrB2. For slow cooling rates, the formation of the compound ZrB by a peritectoid reaction and most likely stabilized by light elements (carbon, nitrogen, oxygen) has been observed. After rapid quenching, TEM investigations revealed the formation of a zirconium-based metastable phase; this new phase, with a nearly fcc structure, has been found in thin foils and is directly related to hexagonal Zr by a Shoji–Nishiyama orientation relationship. The structure at interfaces with habit planes featured by trigonal symmetry ({0 0 0 1} for hexagonal and {1 1 1} for fcc), has been investigated using weak-beam diffraction contrast and high-resolution transmission electron microscopy. The interfaces with a small difference in lattice parameter are accommodated by a misfit dislocation network, whilst those with a large difference in lattice parameter exhibit a more complex structure with ledges and facets. © 1998 Kluwer Academic Publishers     

Impact of modelling approximations in supply chain analysis – an experimental study

This paper presents a study of the comparison of the quality of results obtained at different levels of detail using a supply chain simulation. Analysis of supply chain is typically carried out using aggregated information to maintain the level of complexity of the simulation model at a manageable level. Advances in simulation have provided the ability to build comprehensive (detailed), modular models. The quantitative effect of detailed modelling on the corresponding analysis is investigated in this paper. A three-echelon supply chain is analysed using simulation models of varying levels of detail. Using each of these models, four sets of intensive experiments are performed. The first experiment intends to test whether the supply chain dynamics themselves depend on the modelling accuracy that represents the supply chain. The second and third experiments are conducted to test whether the effectiveness of the strategies employed to reduce the supply chain dynamics vary depending on the type (different detail) of model representing the supply chain. In the fourth experiment, statistical techniques are employed to identify which modelling aspect has the most influence on the supply chain dynamics. It is found that the approximations used in modelling, such as delays and capacity, have more impact on the outcome of supply chain analysis than end customer demand. Evidence that both the basic problem (supply chain dynamics) and the solution (strategy to reduce the dynamics) are greatly influenced by the modelling accuracy are presented.     

Decarbonising product supply chains: design and development of an integrated evidence-based decision support system – the supply chain environmental analysis tool (SCEnAT)

Based upon an increasing academic and business interest in greening the industrial supply chains, this paper establishes the need for a state-of-the-art decision support system (DSS) for carbon emissions accounting and management, mainly across the product supply chains by identifying methodological shortcomings in existing tools, and proposing a supply chain (SC) framework which provide businesses with a holistic understanding of their supply chains and ensuring partners within supply chain collaborative networks have a shared understanding of their emissions. It describes the design and development of a DSS now known as supply chain environmental analysis tool (SCEnAT) in detail, putting its unique and innovative features into a comparative perspective vis-à-vis existing tools and software of different types. The methodological framework used to design and develop SCEnAT integrates different individual techniques/methods of supply chain (SC) mapping, SC carbon accounting, SC interventions and SC interventions evaluation on a range of key performance indicators (KPIs). These individual methods have been used and applied innovatively to the challenge of designing SCEnAT within the desired framework. Finally, we demonstrate the application of SCEnAT, especially the advantage of using a robust carbon accounting methodology, to a SC case study. The SCEnAT framework pushes the theoretical boundary by addressing the problems of intra-organisational approach in decision making for lowering carbon along the supply chain; with an open innovation, cutting edge, hybridised framework that considers the supply chain as a whole in co-decision making for lowering carbon along the supply chain with the most robust methodology of hybrid life cycle analysis (LCA) that considers direct and indirect emissions and interventional performance evaluation for low carbon technology investment and business case building in order to adapt and mitigate climate change problems. This research has implications for future sustainability research in SC, decisions science, management theory, practice and policy.     

Failure of planetary pinions in earth moving equipment—a failure analysis approach

A series of failures of planetary pinions occurred in the final drive epicyclic gearbox of large trucks used in underground mining. A metallurgical analysis indicated that failure had occurred by internal rupture of the gear. This was attributed to poor heat treatment procedures used in case hardening the gear. This had induced high residual stresses just below the case/core interface, leading to the internal rupture of the gear.     

Discussion about the standard system on urban domestic water saving technology in China

Standard is the technical foundation of national economic and social development, and it is the basic rule of establishing social regulation. Researching and constituting the standard system of urban domestic water saving technology is to offer important science basis for revising standard plan and standardize research plan. This paper introduces the present situation of our urban domestic water saving technical standard system, problem and the development direction in the future, as well as project planning of constructing urban domestic water saving technical standard system.     

Failure analysis of transformer liquid — solid insulation system under selective environmental conditions using Weibull statistics method

The failure free operation of transformers is a main factor on economic and safety aspects as per the industrial consumer's point of view. Basically, the transformer is one of the prime equipment in power system network because of its unkind operating condition at different circumstances like higher operating temperature, overloading and continuous operation under uneven outdoor environmental conditions. Above said operating conditions lead to unpredicted failure in the transformer and this directly has an effect on reliability of the power system network. This work aims to investigate the failure rate of transformer liquid insulation (LI)–solid insulation (SI) system at various selective environmental conditions, by considering relative humidity of the air as a frequently variable environmental factor. For investigation, mineral oil (MO) and natural ester like sunflower oil (SFO) and rapeseed oil (RSO) are chosen as the LI system and Kraft paper is chosen as the SI system. The humidified samples are aged at 140 °C up to 1000 h at closed condition. Critical parameters of both LI and SI are periodically measured at an interval of 200 h. Weibull distribution statistics method is used to predict the failure rate of the insulation system with respect to time and relative humidity of the air. From the analysis, it is inferred that the degradation rate of the transformer LI–SI increases with an increase in relative humidity of the air. It is also noted that the LI-MO degrades rapidly when compared with other natural esters.     

Failure assessment of crude oil preheating tubes in mono ethylene glycol–water mixture solution

Aqueous solutions of glycol are commonly used in many applications as heat transfer media. In this study, failure analysis and the leakage of oil tubes in a crude oil pre-heater of a desalting plant were assessed. Crude oil pre-heater (furnace) is a type of heat exchanger in which heat is transferred to oil tubes via ethylene glycol solution in order to increase its temperature for further processing. With the increase of temperature, the viscosity of the oil plus water mixture inside the tubes is reduced and desalting is facilitated. Reports show that, these tubes facing external corrosion in the form of smooth cavities finally lead to leakage. These tubes are made from ASTM A106 Gr B steel. The failure assessment of tubes was carried out by performing various chemical and metallurgical tests. Corrosion coupons were also immersed in ethylene glycol fluid at different places inside the furnace. The investigation revealed that degradation of ethylene glycol forming organic acids (acetic acid, carbonic acid, and formic acid), as the consequent reduction of the pH, take place progressively, being responsible for carbon steel acidic corrosion and eventually to the failure of pre-heating tubes. An action was taken to examine different pH stabilizers for mono ethylene glycol solution. The results obtained by polarization curves showed that, by using stabilizer EN231 at pH = 10.5, corrosion rate reduces to a minimum.     

Dynamics model and analysis of the lifting system of automatic catwalk北大核心CSCD

When the field test of rope pulled automatic catwalk was carried out, the load fluctuation of rope was obvious, and it was difficult to complete the lifting of the target weight column. Therefore, the structure and motion characteristics of rope pulled automatic catwalk were analyzed, and dynamic model based on the D'Alemebert principle was established, MATLAB software was used to analyze the influence of the distance between the block on the base and the bottom of the ramp, the hinge position of the transfer arm and the support arm, and the length of the support arm on the load of rope. The analysis results showed that adjusting the position of block on the base to the bottom of the ramp, and reducing the length of support arm could reduce the required force of rope in the process of lifting. According to the analysis results, the structure size of automatic catwalk was adjusted to carry out the field test, the test result showed that the maximum lifting oil pressure of the hydraulic which was decreased by more than 2 MPa, the lifting capacity of automatic catwalk was improved. The analysis and experimental results can guide the design and optimization of rope pulled automatic catwalk.     

Interdiffusion inα solid solutions of the Cu-Zn-Sn system

The interdiffusion coefficients in the f c c phase of Cu-Zn-Sn alloys, , have been determined at 1073 K. The concentration profiles indicate that the diffusion rate of tin is greater than that of zinc in the Cu-Zn-Sn alloy. The diffusion paths show the typical S-shaped curves. All of the four interdiffusion coefficients are positive and they are very sensitive to the solute concentration. The atomic mobilities of the three diffusing elements in Kirkendall planes increase in the order of Cu, Zn, Sn. The interaction energy of the Cu-Sn bond is much larger than that of the Zn-Sn bond. From the results of the present work it seems that the Onsager reciprocal relation holds in the a phase of the Cu-Zn-Sn system.     

P, ρ, T-properties and phase equilibria in the water-n-hexane system with a low content of water

Using a piezometer of constant volume, we determined experimentally the P, ρ, and T properties and the phase equilibria for the binary water-n-hexane mixtures with 0.04, 0.05, 0.06, and 0.0673 mass fraction of H₂O over the density range of 0.067–0.607 g/cm³, temperature range of 380–680 K, at pressures up to 60 MPa. The equilibrium lines of the liquid-liquid and liquid-gas transition have been determined. The three-phase line, the line of the azeotrope, and the lower branch of the critical line (all lines are joined at the upper finite critical point) have been plotted in the work.     

An analysis of manufacturers’ supply and demand uncertainty based on the dynamic customisation degree

Diverse demands regarding products are common; however, manufacturers usually cannot respond immediately to meet such changes upon demand, and thus, customer satisfaction tends to be reduced. Notebook computer manufacturers adopt a production mode of mass customisation; hence, a certain degree of dynamic customisation measurements, inherent in different supply chain models, allow manufacturers to evaluate costs and profits in advance. The application of the model, as proposed in this study, indicates that the most important factor of the customisation degree is product price. The dynamic customisation degree is adjusted based on monitoring indicators, which requires less total cost and produces greater accuracy in forecast results regarding the prediction model of customer demands. This study develops a dynamic customisation model for total product profits, inventory cost of semi-manufactured products, shortage costs and buffer inventory costs, which are affected by the degree of dynamic customisation of the products. It also analyses the supply and demand uncertainties of the Direct Shipment of the Manufactured Model, as well as the Door-to-Door Direct Shipment of the End User Model in the notebook computer industry, as the criteria with respect to a firm's customisation degree, costs, and profits in different supply chain mode operations.     

Who is in control of road safety? A STAMP control structure analysis of the road transport system in Queensland,Australia

Despite significant progress, road trauma continues to represent a global safety issue. In Queensland (Qld), Australia, there is currently a focus on preventing the ‘fatal five’ behaviours underpinning road trauma (drug and drink driving, distraction, seat belt wearing, speeding, and fatigue), along with an emphasis on a shared responsibility for road safety that spans road users, vehicle manufacturers, designers, policy makers etc. The aim of this article is to clarify who shares the responsibility for road safety in Qld and to determine what control measures are enacted to prevent the fatal five behaviours. This is achieved through the presentation of a control structure model that depicts the actors and organisations within the Qld road transport system along with the control and feedback relationships that exist between them. Validated through a Delphi study, the model shows a diverse set of actors and organisations who share the responsibility for road safety that goes beyond those discussed in road safety policies and strategies. The analysis also shows that, compared to other safety critical domains, there are less formal control structures in road transport and that opportunities exist to add new controls and strengthen existing ones. Relationships that influence rather than control are also prominent. Finally, when compared to other safety critical domains, the strength of road safety controls is brought into question.     

Experience in polyharmonic analysis of the parameters of the earth’s rotation

A method for approximating time series by an nth degree trigonometric polynomial for a series of parameters of the Earths rotation, calculated from GPS and GLONASS measurements, is tested. Satisfactory agreement is obtained between the model and experimental data. The results can be used for complex modeling and forecasting of the parameters of the Earths rotation.Translated from Izmeritelnaya Tekhnika, No. 12, pp. 40–42, December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Remains of 137Cs contamination in the city of Goiânia, Brazil

The results of measurements, performed in 1999, of the remaining 137Cs contamination in some of the sites where fragments of a radioactive source of a teletherapy unit had been manipulated in 1987 are presented. This episode occurred in the city of Goiania, during Brazil's worst radiological accident ever reported. Using the technique of gamma ray spectrometry, analyses of both surface and profile soil and vegetable samples were made. High values of 137Cs activity per unit mass were found in soil layers at depths between 10 and 40cm from the surface. Some values exceeded by up to eight times the action level of 22.5 kBq x kg(-1) proposed by the Brazilian National Nuclear Energy Commission (CNEN) during the decontamination process at the time of the accident, for the first year after the accident. Absorbed dose rates at 1 m above the ground were calculated from the data of 137Cs concentration in the soil and compared with those obtained from in situ gamma ray spectrometry and from thermoluminescence dosimetry.     

Colour reproduction analysis of portrait photography in cross-media system: image on the computer monitor–electrophotographic printing

Photography is dominant illustration technique. Two-thirds of illustrations are realised in this technique most in commonly in the digital photography system. The portrait is one of the most present and most challenging photographic motifs which can be, in a technical sense, analysed primarily through monitoring of the changes in the skin colours. Modern publishing is characterised by increasing number of small circulations created in electrophotographic printing and, parallel, in electronic media. This paper deals with the portrait photography created on the computer monitor and with electrophotographic printing and the question if they can be, for consumers, considered to be the same. The evaluation was attended by the visual comparison based on the principle of memory harmonisation and ΔE₀₀ determination. The results point out satisfactory reproduction in the electrophotographic printing of colour portrait photography in comparison to the portrait defined on the computer monitor, although the reproduction results in colour changes for skin colours and primary and secondary colours of additive and subtractive synthesis.