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This study aims to provide a theoretical basis to evaluate the suitability and integrity of corrosion pipes.

The three-dimensional models of the P110S oil pipe with local corrosion damage, general corrosion damage, pitting corrosion damage are established based on the API 579 standard using the nonlinear finite element analysis method for parametric research.

The reliability of the model is verified based on the experimental data from the existing literature. The effects of the oil pipe’s size and the corrosion damage’s type on the residual internal pressure strength are simulated and obtained. What’s more, a basic method for predicting the remaining life of corrosion damaged pipes is proposed.

The authors evaluated the residual strength of various corroded tubing, compared the tubing with different corrosion types and proposed a basic method for predicting the remaining life of the corroded tubing from the corrosion depth.

The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L).

Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film.

Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance.

When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.

The purpose of this paper is to test bagasse extract as an effective corrosion inhibitor.

The bagasse was extracted without any toxic substance and was found to be effective for corrosion of J55 steel.

The inhibition efficiency of bagasse was more than 90 per cent in 3.5 per cent NaCl solution saturated with CO₂ for corrosion inhibition of J55 steel.

The inhibition effect of Saccharum sinense bagasse extract on the corrosion of J55 steel in 3.5 weight per cent NaCl saturated with CO₂ solution was investigated by means of Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, polarization curve and scanning electron microscope.

It can be used as low-cost corrosion inhibitor.

It is an environment-friendly corrosion inhibitor.

This work is original and carried out in Southwest Petroleum University, China. This is not communicated anywhere else.

The paper reports an investigation into the use of aqueous extracts of rice bran as a green inhibitor for corrosion of carbon steel in hydrochloric acid (HCl) solution.

Extracts from the rice bran were used as the main component of an environmentally friendly corrosion inhibitor for use in HCl pickling processes. Inhibition behavior on carbon steel in HCl was investigated by means of mass‐loss tests, polarization curves, electrochemical impedance spectroscopy and atomic force microscopy.

The results show that the extract exhibited good inhibition performance in 1 M HCl. The inhibition efficiency increased with increase in the concentration of the inhibitor and was only moderately affected by temperature variations in the range 303‐363 K. The inhibitive action was due to adsorption on the A3 steel and the adsorption process was consistent with the Langmuir isotherm. The free energy of adsorption (ΔG_ads.) was −4.192 kJ/mol. The negative value of ΔG_ads. indicated spontaneous adsorption of the inhibitor occurred on the surface of A3 steel.

Rice bran extract is an effective inhibitor and can be used to protect carbon steel from corrosion in HCl solution.

The rice bran extracts are an effective green inhibitor and can be widely used in the pickling of metals.

The purpose of this paper is to investigate changes of China’s agri-food exports to Germany caused by China’s accession to WTO and the global financial crisis in a quantitative way. The paper aims to detect structural breaks and compare differences before and after the change points.

The structural breaks detection procedures in this paper can be applied to find out two different types of change points, i.e. in the middle and at the end of one time series. Then time series and regression models are used to compare differences of trade relationship before and after the detected change points. The methods can be employed in any economic series and work well in practice.

The results indicate that structural breaks in 2002 and 2009 are caused by China’s accession to WTO and the financial crisis. Time series and regression models show that the development of China’s exports to Germany in agri-food products has different features in different sub-periods. Before 1999, there is no significant relationship between China’s exports to Germany and Germany’s imports from the world. Between 2002 and 2008 the former depends on the latter very strongly, and China’s exports to Germany developed quickly and stably. It decreased, however suddenly in 2009, caused by the great reduction of Germany’s imports from the world in that year. But China’s market share in Germany still had a small gain. Analysis of two categories in agri-food trade also leads to similar conclusions. Comparing the two events we see rather different patterns even if they both indicate structural breaks in the development of China’s agri-food exports to Germany.

This paper partly originally proposes two statistical algorithms for detecting different kinds of structural breaks in the middle part and at the end of a short-time series, respectively.

The semantic relations between Arabic word representations were recognized and widely studied in theoretical studies in linguistics many centuries ago. Nonetheless, most of the previous research in automatic information retrieval (IR) focused on stem or root-based indexing, while lemmas and patterns are under-exploited. However, the authors believe that each of the four morphological levels encapsulates a part of the meaning of words. That is, the purpose is to aggregate these levels using more sophisticated approaches to reach the optimal combination which enhances IR.

The authors first compare the state-of-the art Arabic natural language processing (NLP) tools in IR. This allows to select the most accurate tool in each representation level i.e. developing four basic IR systems. Then, the authors compare two rank aggregation approaches which combine the results of these systems. The first approach is based on linear combination, while the second exploits classification-based meta-search.

Combining different word representation levels, consistently and significantly enhances IR results. The proposed classification-based approach outperforms linear combination and all the basic systems.

The work stands by a standard experimental comparative study which assesses several NLP tools and combining approaches on different test collections and IR models. Thus, it may be helpful for future research works to choose the most suitable tools and develop more sophisticated methods for handling the complexity of Arabic language.

The originality of the idea is to consider that the richness of Arabic is an exploitable characteristic and no more a challenging limit. Thus, the authors combine 4 different morphological levels for the first time in Arabic IR. This approach widely overtook previous research results.

The peer review history for this article is available at: https://publons.com/publon/10.1108/OIR-11-2020-0515

Important reserves of oil and gas, which are left to be discovered and produced, are mainly concentrated in challenging locations and under severe conditions such as high pressure (HP)/high temperature (HT). The presence of aggressive environments including H₂S, CO₂ and chlorides plus HP/HT causes a series of corrosion problems, which cost the oil industry billions of dollars a year. Thus, there is an increasing challenge for tubes (i.e. oil country tubular goods, for short, OCTG) used in producing oil and gas. The purpose of this study is to summarize different kinds of corrosion problems and their mitigation, to more efficiently protect OCTG from corrosion.

To effectively select proper mitigation methods, the mechanism of corrosion must be understood, which can be classified into four categories: sweet corrosion, sour corrosion, galvanic corrosion and microbiologically induced corrosion. Also, the effects of environmental and material factors on the corrosion rate are presented. Subsequently, current technology of mitigating these corrosion problems has been discussed, including the development of materials, application of chemical inhibitors and application of protective layers.

It is stressed that limits exist for each individual mitigation method; therefore, a careful balance between economic life of OCTG and safety in operation is required.

The main purpose of this essay is to give a brief review and detailed introduction and analysis about those technologies.

The purpose of this paper is to investigate linkages among competitive strategy, strategic capabilities, environmental uncertainty, and organizational performance in small and medium sized enterprises (SMEs) in China and the USA.

In China, a survey was administered to managers of SMEs in Shanghai and Guangzhou. In the USA, a survey was administered to managers of SMEs in three major cities. Competitive strategy, capabilities, uncertainty, and performance were measured by previously validated scales.

Findings support the integrity Miles and Snow generic strategic typology. Performance satisfaction was significantly lower in firms employing a reactor strategy as opposed to those employing prospector, defender, or analyzer strategies. Additional support was found for the concept of strategic clarity, as businesses reporting moderate strategic clarity had lower levels of satisfaction with performance than those reporting either a single strategy or a combination emphasis on three equal strategies.

Chinese SMEs tend to prefer cost-based approaches to their local markets. A differentiation market approach is challenging in most local Chinese economies due to the low wages of most jobs in an economy that is still largely centrally planned. In the USA, more disposable income leads to more market opportunities. While this situation is gradually changing in China, it is not at a point where SMEs feel comfortable pursuing totally differentiated strategies.

Several distinctions in competitive strategy, capabilities, and environmental uncertainty between China and the USA are recognized by analysis. Analyzers and defenders in Chinese SMEs tend to follow industry prospectors with lower prices and/or superior service. They might change strategies after gaining a foothold in the market. Performance for SMEs with low strategic clarity often depends on established guanxi with governmental agencies or stated-owned enterprises, a situation very different from that in the USA.