Coagulation for treatment of swine slaughterhouse wastewater

In this study, wastewater taken from the Nam Phong swine slaughterhouse, Ho Chi Minh City, was used to evaluate the treatment efficiency of common coagulants, including Alum (Aluminum Sulfate - Al2(SO4)3.18H2O), Poly-Aluminum Chloride (PAC), and Ferrous Sulfate (FeSO4.7H2O), using a jar-test system. The experiments were conducted using the one-factor-at-a-time method to examine three variables which are pH, stirring speed, and coagulant dosage. The results showed that both Alum and PAC perform over 90% removal of colour, turbidity, COD, and total phosphorus (TP) from slaughterhouse wastewater at pH 7 with a stirring speed of 75 revolutions per minute (RPM) and average coagulant dosages of 450 mg/L for Alum and 550 mg/L for PAC. Meanwhile, under the appropriate conditions of pH equal to 10 and 75 RPM with a chemical dosage of 350 mg/L, COD and TP removal efficiencies by Ferrous Sulfate exceed 87%, but those of turbidity and colour only reach 25%. This finding could be a promising coagulation method as a pre-treatment for the swine slaughterhouse wastewater

On Duality, Symmetry and Symmetry lost in Solid Mechanics

International audienceThe paper recalls the concept of duality in Mathematics and extends it to Solid Mechanics. One important application of duality is to restore some symmetry between current fields and their adjoint ones. This leads to many alternative schemes for numerical analyses, different from the classical one as used in classical variational formulation of boundary value problems (Finite Element Method). Usually, Conservation laws in Fracture Mechanics make use of the current fields, displacement and stress. Many conservation laws of this type are not free of the source term. Consequently, one cannot derive path-independent integrals for use in Fracture Mechanics. The introduction of variables and dual or adjoint variables leads to true path-independent integrals. Duality also introduces some anti-symmetry in current fields and adjoint ones for some boundary value problems. The symmetry is lost between fields and adjoint fields. The last notion enables us to derive new variational formulation on dual subspaces and to exactly solve inverse problems for detecting cracks and volume defects

Stick-slip waves between elastic and rigid half-spaces

International audienceThe construction of an analytic solution of the problem of stick-slip waves crossing the interface between an elastic half-space and a tigid one under unilateral contact and Coulomb friction is considered. The method of solution is based on the analytic continuation method of Radok's complex potentials within the framework of steady elastodynamic problems. The governing equations combined with the boundary conditions are reduced to a Riemann-Hilbert problem with discontinuous coefficient, and closed-form expressions of the solution are derived. It is found that the existence of solutions depends on the additional velocity, which is related to the longitudinal elongation. If this velocity is ignored, there is no solution, if not, it is possible to construct weakly singular solutions satisfying all stick-slip conditions except over a narrow zone where the waves exhibit a crack-like behaviour

Translation of Enterprise Architecture Concept to Facilitate Digital Transformation Initiatives in Vietnam : Processes, Mechanisms and Impacts

Governments around the world have increasingly adopted digital transformation (DT) initiatives to increase their strategic competitiveness in the global market. To support successful DT, governments have to introduce new governance logics and revise IT strategies to facilitate DT initiatives. In this study, we report a case study of how Enterprise Architecture (EA) concepts were introduced and translated into practices in Vietnamese government agencies over a span of 15 years. This translation process has enabled EA concepts to facilitate various DT initiatives such as e-government, digitalization, to name a few. Our findings suggest two mechanisms in the translation process: a theorization mechanism to generalize local practices into field-level abstract concepts, making them easier to spread, while a contextualization mechanism unpacks these concepts into practical, adaptable approaches, aligning EA with adopters' priorities and increasing its chances of dissemination. Furthermore, our findings illustrate how translation happened when the initial concepts are ambiguous and not-well-understood by adopters. In this situation, there is a need for widespread experiments and sense-making among pioneers before field- and organizational-level translation can occur.©2023 Association for Information Systems.fi=vertaisarvioitu|en=peerReviewed

Translation of Enterprise Architecture Concept to Facilitate Digital Transformation Initiatives in Vietnam: Processes, Mechanisms and Impacts

Governments around the world have increasingly adopted digital transformation (DT) initiatives to increase their strategic competitiveness in the global market. To support successful DT, governments have to introduce new governance logics and revise IT strategies to facilitate DT initiatives. In this study, we report a case study of how Enterprise Architecture (EA) concepts were introduced and translated into practices in Vietnamese government agencies over a span of 15 years. This translation process has enabled EA concepts to facilitate various DT initiatives such as e-government, digitalization, to name a few. Our findings suggest two mechanisms in the translation process: a theorization mechanism to generalize local practices into field-level abstract concepts, making them easier to spread, while a contextualization mechanism unpacks these concepts into practical, adaptable approaches, aligning EA with adopters\u27 priorities and increasing its chances of dissemination. Furthermore, our findings illustrate how translation happened when the initial concepts are ambiguous and not-well-understood by adopters. In this situation, there is a need for widespread experiments and sense-making among pioneers before field- and organizational-level translation can occur