Alternative Processing Options Research Articles

The impact of landfill management approaches on methane emissions.

This article reports on how management approaches influence methane emissions from landfills. The project team created various landfill operational scenarios for different regions of the planet with respect to waste composition, organic waste reduction and landfill gas recovery timing. These scenarios were modelled by applying a basic gas generation model according to the United Nations Intergovernmental Panel on Climate Change (IPCC) recommendations. In general, the IPCC's recommended modelling parameters and default values were used. Based on the modelling undertaken, two options stand out as being the most effective methane mitigation measures in a wide range of conditions throughout the world: (a) early gas recovery and (b) reduction of the amount of biodegradable organic waste accepted in a landfill. It is noted that reduction of organic input to any given landfill can take many years to realize. Moreover, suitable alternative processing or disposal options for the organic waste can be unaffordable for a significant percentage of the planet's population. Although effective, organic waste reduction cannot therefore be the only landfill methane mitigation measure. Early landfill gas recovery can be very effective by applying basic technologies that can be deployed relatively quickly, and at modest cost. Policymakers and regulators from around the globe can significantly reduce adverse environmental impacts from landfill gas emissions by stimulating both the early capture and flaring and/or energy recovery of landfill gas and programmes to reduce the inflow of organic waste into landfills.

Alternative Processing Options for Improving the Proteins Functionality by Maillard Conjugation.

Conjugation of the proteins with carbohydrates, occurring in the early stages of the Maillard reactions, received increased attention because of the high potential to ensure the improvement of the biological activity and functional properties of the proteins of different origins. The Maillard conjugates are conventionally formed through wet or dry heating, but the use of alternative technologies involving ultrasound, microwave, pulsed electric fields, high-pressure, or electrodynamic treatments appears to be efficient in accelerating the reaction steps and limiting the formation of toxic compounds. An overview of the mechanisms of these processing technologies, the main parameters influencing the Maillard conjugate formation, as well as their advantages and disadvantages, is provided in this paper. Different strategies employing these alternative technologies are reported in the literature: as pretreatment of the proteins, either alone or in admixture with the carbohydrates, followed by conventional heating, as a single alternative treatment step, or as a combination of heating and alternative processing. The desired functional properties of the proteins can be achieved by selecting the appropriate processing strategy and optimizing the reaction parameters. Moreover, alternative technologies can be exploited to obtain Maillard conjugates with remarkable biological activity in terms of antioxidant, antimicrobial, antihypertensive, anti-inflammatory, antimutagenic, or bifidogenic properties.

Renewable chemical feedstock supply network design: The case of terpenes

Designing supply networks enabled by renewable chemical feedstocks presents complexities in terms of undefined markets, multiple intermediate chemical compound options and uncertain chemical conversion pathways. This research addresses this gap by developing a structured approach for designing compound class defined supply chains (SCs) through involving the analysis of: (i) renewable chemical feedstock sources; (ii) alternative technology and processing options; (iii) intermediate or end-user markets; and (iv) commercial value and viability. In particular, we apply this approach on the promising case of terpenoid feedstocks. Further, in the specific case of terpenes we analyse renewable feedstock SC options for the production of ‘green’ pharmaceuticals demonstrated by a case study on paracetamol. To that end, evidence is obtained through collating the dispersed literature on renewable chemical feedstocks, by semi-structured interviews and through expert panel engagements involving industry and academic informants. The study findings inform about the systemic mapping and modelling of compound class defined material-processing-supply networks, further providing a basis to identify feasible intermediate and final product options. The research contributes to the operations management academic and practice literature by proposing a structured approach for mapping and designing renewable chemical feedstock SCs from a source material perspective, in this case renewable terpenoid feedstocks, in contrast to the traditional end-market applications. From a circular economy perspective, the use of renewable feedstocks in extended SCs demonstrates the utility of the approach by integrating supply side considerations (i.e. feedstock) with uncertainties of intermediate processing options and commercialisation routes.

Methodology to identify appropriate options to manage tritiated waste

Fusion facilities will use tritium as a part of fuel. As a consequence, most of waste is expected to be contaminated with tritium and specific waste management strategies need to be developed taking into account physical and chemical properties of tritium. In France, the reference strategy for waste exceeding acceptance limits for disposal due to its tritium inventory is an interim storage period up to 50 years, corresponding approximately to detritiation factor of 16 due to radioactive decay.This article is mainly focused on the most tritiated categories of waste that would require an interim storage period longer than 50 years. Alternative strategies or additional processing options have been sought for these categories and the article defines methodology of identification of the Best Available Technique (BAT) for reduction of tritium inventory in the waste. Furthermore, the methodology is demonstrated on the case of purely tritiated metallic waste made from stainless steel. The methodology has been divided into three main steps: 1) Identification of the most relevant detritiation techniques; 2) Comparative analysis; and 3) Economical assessment. In order to simplify the first step, a software tool has been developed by CEA and its main features are described in this article. The results given by this tool are then analysed in the second step, which takes into account several non-economic criteria. Results of the comparative analysis show that detritiation of purely tritiated metallic waste made from stainless steel appears to be very attractive, allowing a significant reduction of interim storage duration before disposal in a surface repository. The last step, briefly described in this article, is ongoing and will economically assess the results from the previous steps.

Development and evaluation of feature-focused dynamic routing policy

This paper reports on a development of feature-focused dynamic routing policy and its evaluation in a flexible manufacturing systems (FMS) simulation framework. The dynamic policy is based on an integrative methodology in which process planning system IMPlanner is integrated with FMS simulation module. IMPlanner’s rule-based system process selection system performs knowledge-intensive task of generating alternative processing options for each feature for parts in production plan. Generated alternative routings (process plan network) for each part are utilized in the FMS simulation module such that routing decision in FMS are made on periodic intervals by considering alternative processes for each feature and making decision based on the current system status and performance. The proposed framework has been evaluated in an experimental FMS simulation module, implemented in Arena, in which two performance criteria, machine utilization and WIP, were used to make routing decisions. The feature-focused approach is compared with traditional static decision-making, and its improved performance is demonstrated.

Characterization of Blue Agave Bagasse (BAB) as Raw Material for Bioethanol Production Processes by Gravimetric, Thermal, Chromatographic, X-ray Diffraction, Microscopy, and Laser Light Scattering Techniques

A detailed characterization of the main types of blue agave bagasse (BAB) obtained from the four largest tequila factories in the State of Jalisco (Mexico) is presented here. After milling/sieving the agave bagasses, two particle size fractions were identified, one rich in fibers and the other consisting of dust/fine particles. Both fractions were analyzed to determine the content of cellulose, hemicellulose, lignin, organic-soluble compounds, absorbed remaining sugars, minerals, and organic matter. After detailed analyses of both fractions by wet, thermal (thermo-gravimetric analysis (TGA)/differential thermo-gravimetric analysis (DTA)), and other methods (high-performance liquid chromatography (HPLC), microscopy, particle size by laser diffraction light scattering, and crystallinity by X-ray diffraction), a moderate-to-intensive method was devised for further processing the fibrous fraction, which had a high crystalline cellulose content, as well as for its subsequent enzymatic saccharification under well-defined moderate conditions. Alternative processing options were also devised for the dust/fine particle fraction, which has a moderate crystalline cellulose that is rich in adsorbed sugars and that has a high mineral matter content.

Modern analysis of an ancient integrated farming arrangement: life cycle assessment of a mulberry dyke and pond system

Integrated agriculture and aquaculture (IAA), as typified by the mulberry dike-pond system (DPS) of the Pearl River delta of southern China, is often cited as an example of sustainable intensified production due to its characteristic closed loop recycling of nutrients. In this study, we tackle two issues that have been hardly addressed in previous analyses of aquaculture production, greenhouse gas emissions (GHGe) from the pond and the role of labour. Previous assessments led us to revisit the sustainability of the DPS system as a model for a well-studied IAA system using a life cycle assessment (LCA) methodology. Our study quantifies on-farm CH4 and N2O emissions and indirect emissions embedded in inputs, using the global warming potential (GWP) metric. To model the indirect impact of the high labour requirements of the system, a simple methodology based on metabolizable energy requirements is proposed. Our GHGe assessment suggests that using fish ponds to treat organic waste results in higher net emissions than alternative waste processing options (e.g. composting), even when the co-production of fish is accounted for. The majority of total system GWP100 (97 %) can be attributed to methane from the fertilised ponds. Food required to meet labour requirements plays an important role, from 11 to 22 % of total environmental impact. Methane from semi-intensive ponds fertilised with organic waste appears to be a significant source of GWP, calling into question the environmental sustainability of IAA systems such as the mulberry DPS. Improving sustainability in such systems will require better understanding of GHGe from waste-fed aquaculture ponds, notably with respect to on-farm N2O and CH4.

Advanced beamformers for cochlear implant users: acute measurement of speech perception in challenging listening conditions.

ObjectiveTo investigate the performance of monaural and binaural beamforming technology with an additional noise reduction algorithm, in cochlear implant recipients.MethodThis experimental study was conducted as a single subject repeated measures design within a large German cochlear implant centre. Twelve experienced users of an Advanced Bionics HiRes90K or CII implant with a Harmony speech processor were enrolled. The cochlear implant processor of each subject was connected to one of two bilaterally placed state-of-the-art hearing aids (Phonak Ambra) providing three alternative directional processing options: an omnidirectional setting, an adaptive monaural beamformer, and a binaural beamformer. A further noise reduction algorithm (ClearVoice) was applied to the signal on the cochlear implant processor itself. The speech signal was presented from 0° and speech shaped noise presented from loudspeakers placed at ±70°, ±135° and 180°. The Oldenburg sentence test was used to determine the signal-to-noise ratio at which subjects scored 50% correct.ResultsBoth the adaptive and binaural beamformer were significantly better than the omnidirectional condition (5.3 dB±1.2 dB and 7.1 dB±1.6 dB (p<0.001) respectively). The best score was achieved with the binaural beamformer in combination with the ClearVoice noise reduction algorithm, with a significant improvement in SRT of 7.9 dB±2.4 dB (p<0.001) over the omnidirectional alone condition.ConclusionsThe study showed that the binaural beamformer implemented in the Phonak Ambra hearing aid could be used in conjunction with a Harmony speech processor to produce substantial average improvements in SRT of 7.1 dB. The monaural, adaptive beamformer provided an averaged SRT improvement of 5.3 dB.

Investigation of excipient and processing on solid phase transformation and dissolution of ciprofloxacin

Ciprofloxacin, a very slightly soluble antibiotics, is known to exist as both anhydrous and hydrous forms. This study was carried out to investigate the solid phase transformation of ciprofloxacin during conventional formulation processing that impacts the performance of solid dosage forms. In addition, alternative processing and formulation options were also evaluated to circumvent phase transformation. Anhydrate and hydrate of ciprofloxacin were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and powder dissolution. As expected, the anhydrate exhibited significantly higher dissolution rate than the hydrate. However, it rapidly converted to the hydrate upon exposure to aqueous medium. Interestingly, premixing the anhydrate with HPMC in the presence of water or ethanol was found to inhibit the processing-induced phase transition. Further studies demonstrated that wet granulation could be an option for preparing tablets with high loading of ciprofloxacin anhydrate through proper selection of excipients and control of processing conditions. Dissolution study of ciprofloxacin in HPMC based extended release matrix tablets indicated different dissolution rates between tablets containing the anhydrate and hydrate, suggesting transformation to the hydrate was significantly inhibited by HPMC in the gel layer of the hydrated tablets.

An integrated design and planning environment for welding: Part 1: Product modelling

There is extensive literature and industrial evidence that the early stages of product design are particularly important for life-cycle cost control, product quality and manufacturability. The early stages of weld structure design are characterised by the gradual generation and addition of information to a generally incomplete product model. This process includes the identification of component shapes, positions of joints between components and the selection of joining methods, based on the required functionality and applied manufacturing constraints. Aggregate process planning is a methodology for evaluating alternative design and processing options at the early design stages by applying manufacturing process criteria. This paper discusses the definition and implementation of CAPABLE/Welding, a newly developed aggregate process planning system for supporting early design assessment of complex fabrications. The first part of this paper details the overall structure of the aggregate product model implemented in CAPABLE/Welding. An aggregate product model of a fabrication is defined using object-oriented and feature-based methods. The use of relevant design rules to generate weld features is discussed in this paper using as an example the design procedure for a complex fabrication. Methods for abstracting necessary product data from STEP files and directly from a proprietary CAD system are also discussed. The second part of this paper discusses how the product model can be used in aggregate process planning.

Biased cognitive operations in anxiety: Accessibility of information or assignment of processing priorities?

There is considerable evidence that anxiety is associated with a cognitive bias favouring the processing of threat-related information. Bower's (1981) network model attributes this bias to the enhanced availability of mood congruent information from memory. However, certain experimental tasks do not reveal such a bias, when this effect is strongly predicted by the model. We note that all tasks which have demonstrated such mood congruent processing effects in anxious subjects share the requirement that these subjects must assign priorities to simultaneously available, and differentially valenced, alternative processing options. This feature has been consistently lacking in those paradigms we have found insensitive to the influence of anxiety. It is therefore suggested that anxiety is associated with the assignment of high processing priorities to threat-related options, rather than with the facilitated availability of threat-related information from memory. This proposal was experimentally tested using a lexical decision task, which is sensitive to the accessibility of information from memory, under conditions which either do or do not introduce the requirement to assign priorities to alternative processing options. The results indicate that the facilitated processing of threat related stimulus words, shown by generalised anxiety patients, does indeed appear to reflect a bias in the assignment of processing priorities, rather than the enhanced availability of this information from memory.