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Managing Risks in Collaborative Network Organizations Within Sales and Operations Planning: A Maturity Model
No full textPart 7: Collaborative Decision Making 303International audienceSales and Operations Planning (S&OP) is essential for aligning strategic plans with daily operations. However, the dynamic nature of modern Collaborative Network organizations presents challenges due to uncertainties and risks. This research aims to fill this gap by creating a maturity model to manage uncertainties in the S&OP process. A literature review was conducted, examining six key dimensions: Process, Tools, People, Objectives, Decisions, and Key Performance Indicators (KPIs). The review uncovered gaps and limitations in current research on uncertainty management in S&OP, underscoring the need for a maturity model for Collaborative Network organizations. As a result, a three-stage maturity model was developed to evaluate Collaborative Network organizations’ S&OP practices, providing guidance to manage uncertainties within the S&OP process. The study highlights the need for future research to develop well-defined procedures for effectively addressing uncertainties, including scenario planning methodologies and decision-making frameworks that account for uncertainties
Aerogels for Energy Saving and Storage
No full textInternational audienceExplore the energy storage applications of a wide variety of aerogels made from different materials In Aerogels for Energy Saving and Storage, an expert team of researchers delivers a one-stop resource covering the state-of-the-art in aerogels for energy applications. The book covers their morphology, properties, and processability and serves as a valuable resource for researchers and professionals working in materials science and environmentally friendly energy and power technology. The authors offer a comprehensive review of highly efficient energy applications of aerogels that bridges the gap between engineering, science, and chemistry and advances the field of materials development. They provide a Life Cycle Assessment of aerogels in energy systems, as well as discussions of their impact on the environment. Aerogel synthesis, characterization, fabrication, morphology, properties, energy-related applications, and simulations are all explored, and likely future research directions are provided. Readers will also find: •A thorough introduction to aerogels in energy, including state-of-the-art advancements and challenges newly encountered •Comprehensive explorations of chitin-based and cellulose-derived aerogels, as well as lignin-, clay-, and carbon nanotube-based aerogels •Practical discussions of organic, natural, and inorganic aerogels, with further analyses of the lifecycle of aerogels •In-depth examinations of the theory, modeling, and simulation of aerogels Perfect for chemical and environmental engineers, Aerogels for Energy Saving and Storage will also earn a place in the libraries of chemistry and materials science researchers in academia and industry
Introduction to the DIRECT minitrack (Disaster Information, Technology, and Resilience) in the Digital Government track – HICSS 57
No full textInternational audienc
Rotary barrel tumbling as a method of surface preparation for pin-on-disc wear testing samples
No full textInternational audienceSurface preparation is essential to ensure sample homogeneity in terms of surface roughness and mechanical properties, as these factors can significantly affect wear behavior and test repeatability. Although conventional semi-automatic and automatic grinding and polishing processes are efficient and well established, limitations arise for the preparation of large numbers of samples of a hard material such as high-carbon steel, including issues with sample geometry, the need for on-demand sample holders, cost-related limitations, and even considerable human workload and expertise. This study aims to evaluate the use of rotary barrel tumbling—a polishing method that relies on the sliding of abrasive media over the samples’ surface inside a rotating barrel—as an alternative method to prepare the surface of wheel and rail steel samples for pin-on-disc wear testing. A 4-stage tumbling procedure was employed, using different compositions of tumbling media in each stage. Surface roughness and hardness were evaluated throughout the process via 2D and 3D profilometry, microhardness Vickers measurements, and optical microscopy. The proposed method resulted in significant reductions in the surface roughness and hardness of the samples, along with improved homogeneity between samples of different materials and within the same material. These findings suggest that rotary barrel tumbling is an effective alternative method for the surface preparation of pins and discs made of high-carbon steel, enhancing the samples’ suitability for subsequent wear tests
Analysis of a new dynamic capacity management approach in DDMRP: Application on a real industrial case
No full textInternational audiencePurpose: Although the authors of the Demand Driven Material Requirements Planning (DDMRP) argue that the method DDMRP is the solution to the limitations of traditional production management methods, its capacity management system remains unclear. Since DDMRP operates at infinite capacity, it is important to consider a capacity management approach to avoid under- or overloading production workshops.Design/methodology/approach: We propose a new dynamic capacity management approach for the DDMRP method. Our approach is based on the calculation of the anticipated workload, using DDMRP stock buffers and considering customer order spikes. Considering a real industrial case, we compare the proposed approach to a static one and a dynamic approach from the literature.Findings: The analysis of the results, supported by a two-way ANOVA, indicates that the proposed capacity management approach outperforms the performance of the other two approaches by maximizing the resource loading rate while ensuring a high customer service level.Originality/value: The originality of the article comes on the one hand from the capacity adjustment module by calculating the anticipated workload, and on the other hand from the comparison of this approach with two others, one of which comes from the literature
Oxygen production by solar vapor-phase pyrolysis of lunar regolith simulant
No full textInternational audienceThe oxide-rich lunar surface regolith can be used to extract the oxygen needed for the future of lunar exploration efforts as a consumable for life-support systems and spacecraft propulsion. Various techniques for the extraction of oxygen have been developed already, with solar vapor-phase pyrolysis shown to be a promising yet understudied approach. In contrast to other techniques, it requires only locally available resources, such as unbeneficiated regolith, sunlight, and vacuum in order to liberate oxygen and oxygen-bearing molecules. This study presents experimental work conducted in a purpose-built solar-vacuum furnace showing the evaporation of sodium and iron from a regolith simulant sample and their deposition on the crucible surface. This is matched by the thermochemical equilibrium modeling done in FactSage, which analyzes the process at varying pressures down to ultra-high vacuum. It highlights the need for precise temperature and pressure control, as well as the impact of regolith composition on oxygen dissociation for an efficient extraction of molecular oxygen
Fabrication of eco-friendly nanocellulose-chitosan-calcium Phosphate ternary nanocomposite for wastewater remediation
No full textInternational audienceNanocomposites have emerged as promising materials for pollutant removal due to their unique properties. However, conventional synthesis methods often involve toxic solvents or expensive materials. In this study, we present a novel ternary nanocomposite synthesized via a simple, cost-effective vacuum filtration method. The composite consists of calcium phosphate (CaP), biowaste-derived nanocellulose (diameter <50 nm) (NC), and chitosan (CH). The nanocomposite exhibited exceptional pollutant removal capabilities due to the hybrid approach of combining adsorption and size exclusion that widens and accelerates pollutant removal. When tested with synthetic wastewater containing 10 ppm of Ni ions and 10 ppm of Congo red (CR) dye, it achieved impressive removal rates of 98.7% for Ni ions and 100% for CR dye. Moreover, the nanocomposite effectively removed heavy metals such as Cd, Ag, Al, Fe, Hg, Mo, Li, and Se at 100%, and Ba, Be, P, and Zn at 80%, 92%, 87%, and 97%, respectively, from real-world municipal wastewater. Importantly, this green nanocomposite membrane was synthesized without the use of harmful chemicals or complex modifications and operated at a high flux rate of 146 L/m2.h.MPa. Its outstanding performance highlights its potential for sustainable pollutant removal applications
Importance of design and operating parameters in a sonication system for viscous solutions: effects of input power, horn tip diameter and reactor capacity
No full textInternational audienceThis study investigates the distribution of ultrasound (US) energy in a batch system for solutions with viscosity ranging from 1 to approximately 3000 mPas. Sonication was performed using horn type configurations operating at 20-30 kHz and rated power capacity of 50 or 200 W. Two different tip diameters (3 or 7 mm) and two insertion depths (35 or 25 mm) within vessels of different sizes (≈60 or 130 ml) were utilized. Additionally, a special conical tip design was employed. For each experimental set-up, the calorimetric efficiency was estimated, the cavitationally active regions were visualized using the sonochemiluminescence (SCL) method and bubble cluster formation inside the vessel was macroscopically observed using a high speed camera (HSC). In the viscosity range tested, the calorimetry results showed that the efficiency and continuous operation of the device depend on both the rated power and the horn tip diameter. The ratio between electrical and calorimetric power input remained consistently around 40 to 50% across the different configurations for water, but for the 123.2 mPas solution exhibited significant variation ranging from 40 to 85%. Moreover, the power density in the smaller reactor was found to be nearly double compared to the larger one. The SCL analysis showed multiple cavitationally active zones in all set-ups, and the zones intensity decreased considerably with increase of the solutions viscosity. The results for the cone tip were not conclusive, but can be used as the basis for further investigation. The current research highlights the importance of thoroughly understanding the impact of each design parameter, and of establishing characterization methodologies to assist in the future development of scaled-up, commercial applications
Analyse de l'adhérence et de la conformité des interventions chirurgicales entre la programmation et la régulation
No full textInternational audienceLa planification des interventions chirurgicales dans un bloc opératoire se déroule selon trois horizons décisionnels : (1) La planification consiste à attribuer des plages horaires appelées vacations à chaque spécialité ou à chaque opérateur. Elle est réalisée tous les 6 à 12 mois. (2) La programmation cherche à remplir au mieux les vacations avec une séquence d'opérations chirurgicales ayant chacune une heure de début et une heure de fin prévisionnelles. Le programme se constitue au fil des consultations des chirurgiens, mais il est "gelé" 7 jours avant la date d'intervention afin de réserver les ressources nécessaires. (3) La régulation opérationnelle, face aux aléas, permet la réalisation du programme opératoire le jour J. Le facteur humain étant prépondérant, il occasionne des écarts entre la réalisation et la programmation prévisionnelle. Bien que la performance du bloc opératoire ait fait l'objet de nombreux travaux, avec comme résultats des indicateurs aujourd'hui largement connus et utilisés, il n'y a pas de publication à notre connaissance s'intéressant aux écarts entre la programmation des opérations et leur réalisation après régulation. Dans cet article, nous tentons d'analyser l'adhérence et la conformité, deux indicateurs destinés à évaluer l'adéquation de la programmation et de la régulation.A planificação das intervenções cirúrgicas em uma sala de operações ocorre em três etapas decisivas: (1) Planificação propriamente dita: Consiste em atribuir intervalos de tempo, chamados de turnos, para cada especialidade ou cirurgião. Essa planificação é realizada a cada 6 a 12 meses. (2) Programação: Busca preencher os turnos da melhor forma possível, com uma sequência de operações cirúrgicas, cada uma com horário de início e de término previstos. O programa é construído ao longo das consultas com os cirurgiões, mas é “congelado” 7 dias antes da data da intervenção para reservar os recursos necessários. (3) Ajuste: É a fase operacional que permite a execução do planejamneto da operação no dia da cirurgia (dia J). Devido ao fator humano, podem ocorrer discrepâncias entre a execução real e a programação prevista. Embora a eficiência dobloco cirúrgico tenha sido objeto de muitos estudos, com resultados amplamente conhecidos e utilizados, não há, até onde sabemos, publicações que abordem as divergências entre a programação das operações e sua realização após os ajustes. Neste artigo, analisamos a aderência e a conformidade, dois indicadores destinados a avaliar a adequação entre a programação e a execução
Effect of oxygen dissolution on the mechanical behavior of thin Ti-6Al-4V specimens oxidized at high temperature: Experimental and modelling approach
No full textInternational audienceMicromechanical characterization of the oxygen-rich layer (ORL) of a Ti-6Al-4V alloy due to high-temperature oxidation was investigated at room temperature. The tensile strength of the pre-oxidized specimens linearly decreased as a function of the surface fraction of ORL in relation to the gage section, demonstrating a competition between oxygen strengthening and embrittlement. Electron-probe microanalyses and nanoindentation testing aimed at locally assessing the elastic and hardness response of the material as a function of the oxygen content. These properties were used in finite element simulations to quantify stress profiles within the oxygen-graded material for different ORL thickness/specimen thickness couples