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This study aims to apply novel anticorrosive pigments containing silica fume-phosphates (Si-Ph), which were prepared using core-shell technique by covering 80-90 per cent silica fume (core) with 10-20 per cent phosphates (shell) previously, to play dual functions simultaneously as anticorrosive pigments in coating formulations and as an anticorrosive admixture in concrete even if it is not present in the concrete itself. Two comparisons were held out to show the results of coatings on rebars containing core-shell pigments in concrete, and concrete admixtured with silica fume can perform a dual function as anticorrosive pigment and concrete admixture. The evaluation of corrosion protection efficiency of coatings containing core-shell pigments and those containing phosphates was performed.

Simple chemical techniques were used to prepare core-shell pigments, and their characterization was carried out in a previous work. These pigments were incorporated in solvent-based paint formulations based on epoxy resin. Different electrochemical techniques such as open-circuit potential and electrochemical impedance spectroscopy were used to evaluate the anticorrosive efficiency of the new pigments.

The electrochemical measurements showed that concrete containing coated rebars with core-shell pigments exhibited almost similar results to that of concrete admixtured with silica fume. Also, the anticorrosive performance of coatings containing Si-Ph pigments offered protection efficiency almost similar to that of phosphates, proving that these new pigments can perform both roles as anticorrosive pigment and concrete admixture.

Although the new Si-Ph pigments contain more than 80 per cent waste material, its performance can be compared to original phosphate pigments in the reinforced concrete.

The level of mental alertness among students who are in need of study in the preparatory year – Imam Abdul Rahman Bin Faisal University. The level of self-competence of female students who are in need of study in the preparatory year – Imam Abdul Rahman Bin Faisal University. To learn about the relationship between mental alertness and self-competence among students who are in need of study in the preparatory year – Imam Abdul Rahman Bin Faisal University.

The researchers used the experimental method by following the experimental design with two measurements, tribal and posterior, for two groups, one experimental and the other control, due to its suitability to the nature of this research. Research sample: the research community included female students stumbling in the scientific path of Rayyan, the second semester of the academic year 2020–2021 AD, where the researchers selected the research sample in a deliberate manner from the stalled students of 25 students and a random sample of 10 female students was withdrawn to conduct the exploratory study. The number of the basic research sample is 15 female students. Reasons for selecting the search sample: all of the sample members are female students stumbling in the scientific path of Al-Rayyan for the academic year 2020–2021 and all sample members agree to apply the research.

The researchers refer to this to the virtual psychological guidance program-specific objectives, as well as the follow-up of the scientific principles and principles and the legalization of the measurement tools used in the research and the diversity of the program within the parts of the program and the training sought to develop the ability to manage pressures and emotions and training in social skills, awareness and self-awareness and the use of exercises relaxation, breathing and modern self-help, as well as the use of different methods and techniques such as the method of dialogue, discussion, awareness of feelings and problem-solving, which led to a change in behavior and personal characteristics, which led to a change in behavior and personal characteristics, leading to the development of behavior and personal characteristics.

The study aims to design a hypothetical psychological counseling program as a method of health care and its effect on the level of mental alertness and the level of self-efficacy of students who have struggled to study at the Deanship of the preparatory year – Imam Abdul Rahman bin Faisal University. The researchers used the experimental approach and applied this study on a sample of 25 students from the students who failed to study at the Deanship of the preparatory year for the second semester of the academic year 2020–2021 AD and the most important results were that the psychological counseling program as a method of health care had a positive effect on improving the level of mental alertness and the level of self-efficacy among the students who had failed to study. There is a positive correlation between the level of mental alertness and self-efficacy of struggling students as a way of health care.

In Tunisia, foreign commercial exchanges are predominantly maintained via ocean freight and accomplished through eight major ports. The latter play a critical role in the Tunisian economy, whereby nearly 30.7 million tons of goods were transited in 2018. Maintaining their efficiency therefore remains a very important objective to achieve. In this context, the present study is designed to investigate the technical efficiency of respective Tunisian ports over the 16-year period (2005–2020).

The stochastic frontier analysis (SFA) method is applied to measure the associated time-invariant and time-varying technical efficiency. Moreover, through technical inefficiency modeling, effects of both rail connectivity and private sector participation in handling activities on technical efficiency have also been accounted for.

The reached results turn out to reveal well that the Tunisian ports appear to operate below their production frontier, noticeably marked by persistent technical inefficiency. Additionally, the relevant estimates tend to confirm the berth variable associated importance in highlighting production related to Tunisian ports. More particularly, our analysis reveals that the private sector’s participation proves to display a significantly negative association with technical efficiency, while the ports’ rail connectivity turns out to demonstrate a significantly positive correlation with technical efficiency.

The findings of this study can provide port authorities and policymakers with insights into the technical efficiency of Tunisian ports by identifying best practices, the main factors influencing their efficiency (such as rail connectivity and private sector’s participation) and areas for improvement in these ports.

The present study stands as a pioneering attempt to examine the efficiency dimension through the implementation of panel data estimation modeling frameworks, particularly the random-effects and the Battese and Coelli (1995) approaches, applied to measure the technical efficiency of the Tunisian port sector. Similarly, the present study also represents an effective attempt, whereby the effects of exogenous variables, notably the rail connectivity and private sector participation, are thoroughly considered in exploring the technical efficiency of Tunisian ports.

The purpose of this paper is to present the extension of plane wave based method.

The mixed functional are discretized using enriched finite elements. The fluid is discretized by enriched acoustic element, the structure by enriched structural finite element and the interface fluid‐structure by fluid‐structure interaction element.

Results obtained show the potentialities of the proposed method to solve a much larger class of wave problems in mid‐ and high‐frequency ranges.

The plane wave based method has previously been applied successfully to finite element and boundary element models for the Helmholtz equation and elastodynamic problems. This paper describes the extension of this method to the vibro‐acoustic problem.

In this paper, a maintenance strategy based on improved imperfect maintenance actions with stochastic repair times for multiperiod randomly failing equipment is developed. The main objective is to minimize the total maintenance cost by jointly finding the optimal preventive maintenance (PM) cycle and planning horizon.

A model based on the mathematical theory of reliability is developed to minimize the total maintenance cost by jointly finding the optimal couple: PM cycle T* and planning horizon H*. The proposed model aims to characterize the evolutionary impact of imperfect PM actions on the equipment failure rate and the resulting mean number of failures. The conventional threshold accepting (TA) algorithm is implemented to solve the proposed model. A numerical example for a given set of input parameters is presented in order to show the usefulness of the proposed model. A sensitivity analysis of some of the key parameters is performed to demonstrate the coherence of the developed maintenance policy.

The obtained results showed a sensitive trade-off between PM frequency and the total maintenance cost. Performing PM actions more frequently helps significantly to reduce the expected number of corrective maintenance actions and the corresponding total cost. It has also been found that improving the efficiency of the PM actions allows for maintaining the equipment less frequently by increasing the time between successive PM actions.

Given the complexity of the objective function to be minimized and the stochastic nature of the model's parameters, the authors limited this study to equally cyclic production periods over the planning horizon.

The present model aims to provide an integrated maintenance/production comprehensive framework to assist planners in establishing maintenance schedules considering multiperiod randomly failing production systems and the evolutionary impact of imperfect PM actions on the equipment failure rate.

Contrary to the majority of existing works in the literature dealing with maintenance strategies, the authors consider that repair times are stochastic to provide a more realistic framework. In addition, the developed model considers the impact of imperfect maintenance on the equipment's mean time to failure. Thus, the evolutionary impact of imperfect PM actions on the equipment failure rate and the resulting mean number of failures is characterized. Simultaneously, the production planning horizon along with the length of each PM cycle is optimized in order to minimize the total maintenance cost over the planning horizon.

The continuous and rapid growth of remittances has become one of the sources of income for millions of poor families in developing countries. As such, an increase of remittance flow can have a significant impact on the ability of the household not only to get enough food but also to get nutritious foods. Therefore, this study investigates the implication of remittances on food security (FS) in 51 developing countries from 2011–2016.

A dynamic panel estimator is applied to examine remittances and FS nexus.

By using the dynamic panel estimator, the results indicate that the level of food supply tends to be higher in countries with a higher flow of remittances. This study justifies the need for high income as well as high middle-income countries to be more open and receptive to migration as this could indirectly the mean through which host countries can assist economic development in low-income developing countries.

Given the diverse measure of FS, past studies demonstrated a positive association between remittance and FS, but it may focus on only one dimension of FS. To the authors’ limited knowledge, this is not enough to know the importance of remittance in determining the overall FS status. Hence, this study wishes to extend the literature by using a more comprehensive measure of FS and more countries in the sample.

Using organic coatings serves as a key method to protect metal structures against corrosion. Attempts have been made to improve the corrosion inhibition of the coatings using novel types of pigments. This study aims to study the application of organic coatings containing rice straw (RS) waste as anticorrosive pigment for corrosion protection of reinforced steel. The RS was used by precipitating a thin layer of ferrite pigments on its surface to improve their characteristics and corrosion resistance activity.

The evaluation of corrosion behavior of coated reinforced steel with paints containing these novel pigments is reported using different electrochemical methods.

The coatings containing the new prepared RS-ferrite pigments offered good corrosion protection, and coatings containing RS-ZnFe showed the best protection performance.

This paper introduces novel method to prepare treated RS without any burning and to play the role of pigments in anticorrosive paint formulations based on its silica content.

The purpose of this paper is to examine whether Fama–French common risk-factor portfolio investors herd on a daily basis for five developed markets, namely, Europe, Japan, Asia Pacific ex Japan, North America and Globe.

To examine the herd behavior of common risk-factor portfolio investors, this paper utilizes the cross-sectional absolute deviations (CSAD) methodology, covering a daily data sampling period of July 1990 to January 2019 from Kenneth R. French-Data Library. CSAD driven by fundamental and non-fundamental information is assessed using Fama–French five-factor model.

The results do not provide evidence for herding under normal market conditions, either when reacting to fundamental information or non-fundamental information, for any region under consideration. However, Fama–French common risk-factor portfolio investors mimic the underlying risk factors in returns related to size and book-to-market value, size and operating profitability, size and investment and size and momentum of the equity stocks in European and Japanese markets during crisis period. Also, no considerable evidence is found for herding (on fundamental information) under crisis and up-market conditions except for Japan. Ancillary findings are discussed under conclusion.

Further research on new risk factors explaining stock return variation may help improve the model performance. The performance can be improved by adding new risk factors that are free from behavioral bias but significant in explaining common stock return variation. Also, it is necessary to revisit the existing common risk factors in order to understand behavioral aspects that may affect cost of capital calculations (e.g. pricing errors) and valuation of investment portfolios.

This is the first paper that examines the herd behavior (fundamental and non-fundamental) of Fama–French common risk-factor investors using five-factor model.

Technology transfer becoming an important area especially in developing and less developed countries. The purpose of this paper is to address issue of supply chains’ benchmarking based upon their capability to mange technology transfer critical barriers mitigation efforts toward making technology transfer process implementation successful.

The present paper is based on two research stages. Initially, extensive literature review has been made to identify critical barriers. In total, 20 technology transfer critical barriers have been identified from literature review and categorized in to six criteria. In second stage, analytics hierarchy process has been utilized to rank the critical barriers of technology transfer in supply chain and provide a benchmarking framework.

Political barriers (PB) have been analyzed most significant criteria of critical barriers to technology transfer followed by socio-cultural barriers (SO) and economic barriers (EB). “Political instability,” “Difficulty in transfer and diffusion,” “Too expensive,” “Inappropriate/incompetent technology and resource wastage in technologies imported,” “Inactive role of SC members and resistance to change” and “Management attitude” have been found most hindering barrier in their respective category/criterion of technology transfer barriers.

Scope of the present study has been limited to propose framework to benchmark supply chains by analyzing 20 critical barriers of technology transfer grouped in to six dimensions using analytical hierarchy approach based on “ratings provided by experts,” which may be biased.

Benchmarking process has been proposed to calculate value of total of overall weights to a particular supply chain named as “Technology Transfer Barriers Mitigation Index (TTBMI)” useful to present capability of supply chains to manage technology transfer barriers by a single numeric value. From “provider” developed county’s view point, present benchmarking framework may be further applied to compare developing countries’ ability to absorb and diffuse new technology.

Benchmarking procedure has been dealt with using well-established methodology- analytical hierarchy process toward providing single numeric value index (TTBMI) indicating ability of supply chains to manage/mitigate technology transfer barriers.

This paper aims to evaluate the ability of Aubepine and Molokhia extract, obtained by cathodic electrochemical treatment (CET), to protect steel rebar against attack by chloride ions in environment of reinforced concrete marine structures. The effect of Aubepine and Molokhia extract was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques.

This experimental work has achieved particularity to compare the behaviour of two types of treatment (carbon steel treated one time by Aubepine extract and one time by Molokhia extract) submitted to the presence and absence of chloride ions.

The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel. Inhibition was found to increase with increasing concentration of Molokhia extract and for Aubepine extract maximum concentration is 1 g/L.

Plant extracts and traditional medicinal herbs have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors.

Aubepine and Molokhia extract are novel green plants extract as corrosion inhibiting coating for steel embedded in concrete. Aubepine is a genus of trees in the family Rosaceae and Molokhia is the leaves of Corchorus olitorius. Flavonoids content was found in both of Aubepine and Molokhia extract as green inhibitors for corrosion of metals.