Human resource: what contribution to flexibility? Case study: A Group of Algerian Company

Evaluation is pervasive and it is necessary for everyone to know its need because it has a big impact on the company accordingly it highlights the needs and the decisions taken of the organization. In the current context where the environment is characterized by complexity and uncertainty, companies must adapt and respond quickly to change. Human capital is considered as a resource for the organization, the most important without any doubt. The role of HR is to encourage initiatives to develop the potential sources of flexibility. Thus the assessment remains essential and necessary at the time of the transition of the Algerian economy to a market economy. Our problem is as follows: the human resource is a brake or business flexibility factor? Our study attempts to explore and apply the research tool of Volberd practiced by a group of companies, such as two-dimensional concept of flexibility in order to characterize their flexibility profiles and highlight the contribution of human resources, as a variable flexibility

The thermal properties of mortars modified by the effect of combining polymers and SCMs

The thermal performance of the building materials is relevant to any use of composite materials, especially in relation to constructions where it is desirable to have high specific heat, low thermal conductivity and slight or no decrease of stiffness upon heating. The thermal coefficients of composite mortars made up of mixtures of combining styrene polyacrylic SPA Latex and supplementary cementitious materials SCMs were measured at different ages (7, 14, 28, 60, 90 and 120 days). So, in order to determine the thermal conductivity, the calorific capacity and thermal diffusivity of SCM-modified mortars, it seemed interesting to evaluate the influence of adding the SPA Latex (0.5%, 1% and 2%w) on the properties of these mortars when exposed to a quick thermal conductivity meter based on standard ISO 8302-91. The highest thermal conductivity of 1.51 W.m-1.K-1 was observed with the samples containing only plain cement. It decreased with the increase of SPA latex percentages. The lowest values of thermal coefficients were obtained with the samples prepared with SPA polymer at 2% and SCMs. In this way, the results obtained highlight the beneficial effect of combining SPA polymer and SCM materials as thermal insulation in comparison with other insulation materials. In fact, using SCMs as cement substitutes reduces the energy consumption. These composite mortars address problems related to environmental pollution by CO2 emissions, and can be recommended as materials for energy efficiency in buildings

Chemical, mechanical and thermal properties of mortar composites containing waste PET

International audienceThe main objective of this study was to investigate the potential utilization of polyethylene terephthalate PET waste incementitious matrix, as substituent to cement, to develop lightweight construction materials and for preventing chemical attacksor repairing various reinforced concrete structures. Composites containing different amounts of PET particles, as partialreplacement to cement by weight, were characterized by destructive and non-destructive testing. So, the thermal conductivity,ultrasonic pulse velocity (UPV) and sorptivity coefficients of composite made up of mixtures of PET polymer were measured;the adverse environmental conditions are simulated by using various acid solutions. The corrosion process was monitored bymeasuring the mass loss and compressive strength for different periods. The experimental investigation revealed that the additionof PET particles reduces the UPV; furthermore, thermal conductivity and sorptivity of the composites have been decreased. So,the decrease of the sorptivity-value is favorable to the durability of the specimen structures. On behalf of the resistance toaggressive environments, it was found that the course of action of acid attack is dependent on the type of acid and solubility ofthe calcium salt formed. The presence of PET was found to lower the detrimental effect of acids on composite. Scanning electronmicroscope (SEM), X-ray diffraction and FT-IR analyses were used to better understand the cement hydration products of thedeteriorated mortars. In this way, the obtained PET-mortar composites would appear to be low-cost materials which wouldcontribute to resolving some of the solid waste problems in addition to conserving energy

Experimental and Theoretical Investigations of Argania spinosa’s Extracts on the Antioxidant Activity and Mild Steel Corrosion’s Inhibition in 1 M HCl

The aim of the present research is the evaluation of the extraction process effect on the chemical composition, the antioxidant activities, and the mild steel corrosion inhibition ability of Argania spinosa’s extracts (alimentary oil (AO) and hexanic extract of roasted almonds (HERA)). The chemical composition revealed that both extracts have the same major compounds: Palmitic, linoleic, and stearic acids, with their order slightly different. Electrochemical impedance spectroscopy (EIS), weight loss measurements, and polarization curves were used to estimate AO and HERA’s mild steel corrosion’s inhibition capacity. Based on these three methods, AO registered, respectively, 81%, 87%, and 87% inhibition efficiency while HERA registered 78%, 84%, and 82% inhibition efficiency. The antioxidant activity of AO and HERA was examined in parallel with standard antioxidants (gallic acid and quercetin) using two assays: DPPH* scavenging assay and ferric reducing antioxidant power assay (FRAP). AO had less EC50 in both techniques (DPPH*: 3559.08 ± 161.75 μg/mL; FRAP 1288.58 ± 169.21 μg/mL) than HERA (DPPH*: 3621.43 ± 316.05 μg/mL; FRAP 1655.86 ± 240.18 μg/mL). Quantum chemical and molecular dynamic studies were employed to suggest the adsorption mechanism