Process Optimization

1. ABSTRACT The JPL-led CSP Consortium of enterprises representing government agencies and private companies has joined together to pool in-kind resources for developing the quality and reliability of chip scale packages (CSPs) for a variety of projects. Since last year, more than 150 test vehicles, single- and double-sided, have been assembled and are presently being subjected to various environmental tests.

A hybrid in situ bioremediation/pulsed pumping strategy has been developed to cost effectively remediate a carbon tetrachloride plume in Schoolcraft, Michigan. The pulsed pumping system uses a line of alternating injection and extraction wells perpendicular to the direction of natural groundwater flow. The wells pump periodically to clean the recirculation zone between adjacent wells. During the pump-off phase, natural groundwater flow brings new contaminant into the recirculation zone. The wells are pumped again prior to breakthrough of contaminant from the recirculation zone.A computationally efficient reactor model has been developed, which conceptually divides the aquifer into injection, extraction, and recirculation zones, which are represented by a network of chemical reactors. Solute concentration histories from three-dimensional finite difference simulations and from field data confirm the reactor model predictions. The reactor model is used to investigate the optimal well c...

Weld quality mainly depends on the weld bead geometry and mechanical-metallurgical characteristics of the welded joint which has a direct relationship with the type of welding process being used and its input process parameters i.e. welding current, arc voltage, travel speed etc. In the present study, determination of tungsten inert gas (TIG) welding input parameters for achieving maximum tensile strength of 316L austenitic stainless steel is investigated. Box-Behnken design of response surface methodology has been employed to formulate the experimental plan to identify the effect of process parameters on tensile strength. Square butt joint configuration has been made using three factors - three levels of welding input parameters. Joint strength has been evaluated by notch tensile strength (NTS) and Unnotch tensile strength (UTS) method and correlated with microstructure and micro hardness of the weld. The results indicate that gas flow rate has greater influence on both NTS and UTS...

Blank design is an important task in sheet metal forming process optimization. The initial blank shape has direct effect on the part quality. This paper presents a deformation based blank design approach to determine the initial blank shape for a formed part. The blank design approach is integrated separately into ABAQUS, and DD3IMP, a research purpose in-house FEA code, to

Abstract-Biochemical changes related to stability of food waste compost are strongly affected by different composting techniques. For evaluation of compost maturity three locally fabricated composters and windrow process were examined at seven days interval up to 91 days by ...

Most of the machine learning-based intrusion detection tools developed for Industrial Control Systems (ICS) are trained on network packet captures, and they rely on monitoring network layer traffic alone for intrusion detection. This approach produces weak intrusion detection systems, as ICS cyber-attacks have a real and significant impact on the process variables. A limited number of researchers consider integrating process measurements. However, in complex systems, process variable changes could result from different combinations of abnormal occurrences. This paper examines recent advances in intrusion detection algorithms, their limitations, challenges and the status of their application in critical in-frastructures. We also introduce the discussion on the similarities and conflicts observed in the development of machine learning tools and techniques for fault diagnosis and cybersecurity in the protection of complex systems and the need to establish a clear difference between them. As a case study, we discuss special characteristics in nuclear power control systems and the factors that constraint the direct integration of security algorithms. Moreover, we discuss data reliability issues and present references and direct URL to recent open-source data repositories to aid researchers in developing data-driven ICS intrusion detection systems.

With increasing demand for hydrogen as an environmentally friendly fuel, the catalytic steam reforming of natural gas is gaining prominence as the most attractive processes for production of hydrogen. In the conventional catalytic steam reformer (CSR), the maximum achievable conversion is limited by equilibrium. This limitation is overcome in a membrane steam reformer (MSR), in which the equilibrium is shifted towards higher methane conversion by continuously removing hydrogen from the reaction site and letting it permeate out through a palladium membrane. In spite of this advantage, no industrial scale application of MSR has so far been reported and this is mainly due to high cost of preparation of Pd membrane. In this work, a mathematical model is developed to represent the industrial scale operation of a MSR. The model is simulated to analyse the effect of various operating parameters on performance of MSR. An optimization study is carried out to obtain the optimum values of operating parameters at which the methane conversion is maximum. Effect of increasing the area of Pd membrane on the performance of MSR is studied. It is shown in this work that it is possible to achieve up to 99.9% methane conversion in MSR.

Naša naloga bo izvesti modeliranje in simulacijo na osnovi treh delovnih procesov. Delovne procese sestavljajo trije pravilniki, ki se izvajajo na Fakulteti za informacijske študije v Novem mestu, in sicer: Pravilnik o anketiranju študentov, pravilnik o študentih s posebnim statusom ter pravilnik o izvajanju delovne prakse. Vse tri pravilnike bomo najprej opisali in nato izdelali tabelo aktivnosti in tabelo lastnosti (metodologija TAD) za vsak delovni proces. Pomagali si bomo s programskim orodjem iGrafx, kjer bomo izvedli modeliranje in simulacijo. Na podlagi rezultatov simulacije bomo ugotovili kako posamezna aktivnost vpliva na celoten proces ter podali predlog za izboljšavo le-te.
KLJUČNE BESEDE:
Delovni proces, modeliranje, simulacije, metodologija TAD, programsko orodje iGrafx.

In conventional thermal spraying, the spray particles are partially or fully molten when they deposit on the substrate. Cold spraying, in contrast, uses less thermal and more kinetic energy. In this process, solid particles impact on the substrate at high velocities and form excellent coatings. Due to comparatively low temperatures and typically inert process gases, cold spraying is particularly suitable for heat and oxidation sensitive materials. In recent years, modeling and computational methods have been widely used to study this relatively new spraying process, particularly to describe impact conditions of particles, to improve nozzle design, and to provide a better understanding of the thermo-mechanical processes that lead to particle bonding and deposition. This paper summarizes the state of the art in these theoretical studies, alongside a comprehensive description of the process. The paper also discusses the prediction of coating properties in the light of modeling combined with experimental investigations.

An improved, safe, and scalable isolation process for (substituted) pyridine and quinoline N-oxides in quantitative yields along with high purities using the m-CPBA−NH 3 (g) system is described. The safety was assessed by reaction calorimetry and differential scanning calorimetry studies for possible hazards during the conversion and isolation steps. Careful interpretation of the data substantiated the safety and scalability. The process flow is simplified to meet the industrial requirements of safety, cost-effectiveness, and utility minimization. The reaction was safely demonstrated at a 2.5 kg scale.

During the last decade, a major shift has begun in chemical industry, since there is an urgent need for new tools that are able to support the optimization of operating technologies. This trend is driven by the new tools of information technology. Approaches of this shift differ from company to company but one common feature is that communication between design, manufacturing, marketing and management is centered on modeling and simulation, which integrates not only the whole product and process development chains, but all the process units, plants, and subdivisions of the company. These approaches are under continuous development. Among the wide range of possible improvements, this paper focuses to two frequent imperfections: (i) developed and refined process models are used only in advanced process control system (APC) integrated into distributed control system (DCS) and operator training systems (OTS), and not for detailed analysis and optimization, and (ii) optimal process operating points of these chemical plants are adjusted only at the design and test phase of a new technology, but optima moves with time, new catalyst system, lower price of reactants, claim for new or higher purity products, etc. The aim of this paper is to review, how to manage process optimization, and to show our process simulator based on the chemical engineering model of the technology. This paper will present a case study to demonstrate the technological and ecological benefits of the analysis and optimization of an B. Balasko et al. operating multi-product polymerization plant. The models of advanced process control system (APC) and reactor cascade were implemented in MATLAB ® Simulink ® environment, as a powerful and popular dynamic simulator.

Lactic acid bacteria (LAB) have a long tradition of use in the food industry, and the number and diversity of their applications has increased considerably over the years. Traditionally, process optimization for these applications involved both strain selection and trial and error. More recently, metabolic engineering has emerged as a discipline that focuses on the rational improvement of industrially useful strains. In the post-genomic era, metabolic engineering increasingly benefits from systems biology, an approach that combines mathematical modelling techniques with functional-genomics data to build models for biological interpretation and--ultimately--prediction. In this review, the industrial applications of LAB are mapped onto available global, genome-scale metabolic modelling techniques to evaluate the extent to which functional genomics and systems biology can live up to their industrial promise.

The process conditions for a high-efficiency and low cost crystalline silicon solar cell were optimized. Novel approaches such as wafer cleaning and saw -damage removal using 0.5wt% of 2,4,6-trichloro-1,3,5-triazine, silicon surface texturing with optimized pyramid heights (∼5μm), and a third step of drive-in after phosphosilicate glass (PSG) removal followed by oxide removal were investigated. A simple method of chemical etching adopted for edge isolation was optimized with edge etching of 5–10μm, without any penetration of chemicals between the stacked wafers. The conversion efficiency, open-circuit voltage, short-circuit current, and fill factor of the cell fabricated with the optimized process were a maximum of 17.12%, 618.4mV, 5.32A, and 77% under AM1.5 conditions, respectively.

Clitoria ternatea L. commonly known as ‘blue pea’ is an underutilized plant in Sri Lanka. The blue coloured flower of this plant is used in medicine in Sri Lankan traditional medical system and also reported to have several health benefits in recent findings at the international level. However, to date scientifically validated value added products from blue pea flower (BPF) is very limited worldwide. In this connection, this study was carried out to develop a commercial potential blue pea flower extract (BFE) incorporated beverage having functional properties. Dried BPFs were extracted into water with varying flower: water ratio, temperature, and time using response surface methodology (RSM) along with Box–Behnken design. A range of BFE incorporated beverages was developed comprising a natural sweetener (Stevia extract) and a flavour (lime). The most acceptable formulation was selected via ranking and hedonic sensory tests. Further, it was evaluated for functional properties in term...

Résumé :
Les bioréacteurs anaérobies sont aujourd’hui des moyens performants pour dépolluer les eaux usées des industries agro-alimentaires. Leur capacité à transformer les polluants en biogaz tel que le méthane offre de plus un intérêt écologique et énergétique non négligeable puisqu’ils s’inscrivent aujourd’hui dans les sources d’énergies renouvelables. Cependant, la mise en oeuvre des bioréacteurs anaérobies reste souvent sous optimale, notamment pendant les phases de démarrage pour lesquelles les modèles disponibles sont insuffisamment précis, notamment en ce qui concerne la prédiction des profils de biomasse. A partir d’un modèle existant, un modèle de tendances a été développé pour prédire de façon indépendante la biomasse en solution et la biomasse agglomérée en biofilm. L’identification des paramètres du modèle a été réalisée à partir de données de démarrage d’un bioréacteur appartenant au Laboratoire de Biotechnologie de l’Environnement de l’INRA de Narbonne. Ce modèle a été utilisé pour déterminer le profil de commande optimal du taux de dilution et de la concentration d’alimentation en substrat à appliquer au système pour réduire le temps d’atteinte d’un rendement épuratoire pré-spécifié. Une étude sur la régulation du rendement épuratoire avec le taux de dilution a aussi été réalisée et montre un bon compromis entre un excellent taux d’épuration et une vitesse de démarrage intéressante.

Abstract:
Today, anaerobic bioreactors are high-performance industrial facilities that are able to remove polluted wastewaters of the food-processing industries. Their capability to transform pollutant is interesting on an ecologic and energetic perspective, since biogases are deemed to be renewable energy sources. However, anaerobic digestion is often performed in a suboptimal manner, notably during the starting phases since biomass concentration transitory profiles are not correctly modelled. A tendency model has been developed on the basis of an existing dynamic model to predict independently bacteria in the solution and bacteria that are bound together in a biofilm. Model parameter identification has been performed using data obtained on the bioreactor of the Environmental Biotechnology Laboratory of the INRA of Narbonne. With this tendency model, optimal control profiles have been found, in terms of dilution rate and organic substrate inlet concentration. Applying this optimal profile to the system leads to a reducing of the time needed to reach a pre-specified yield. In addition, dilution rate was used to control the purification yield. This case study raised a good compromise between high purification rate and a significant final time reduction of the start-up phase.