ENHANCED GRAPH BASED WORD REPRESENTATION FOR BIOMEDICAL NAMED ENTITY RECOGNITION

As the biomedical literature continues to expand rapidly, the significance of extracting biomedical-named entities from this extensive body of work is steadily increasing. Bio-NER presents a greater challenge compared to general entity recognition due to the non-standard use of abbreviations, synonyms, homonyms, ambiguities, and the continual creation of new biomedical entity names. These factors combine to create a significant hurdle in the accurate identification and classification of biomedical entities. The underperformance of machine learning models in biomedical text analysis is primarily attributed to the inadequate representation of these texts through manually created features. In addressing this challenge, this study aims to create enhanced word representation methods to improve biomedical named entity recognition and are based on enhanced graph-based word representation techniques, utilizing machine learning approaches: CRF, SVM, and ensemble learning. These methods are assessed using the well-known GENIA corpus. The results show that SVM, CRF and ensemble learning with morphological, orthographic and context features achieves good results with overall F-measure of (54.6%), (81.87%) and (85.64) respectively. In addition, experimental results also show that enhanced graph-based word representation techniques achieve higher performance with overall F-measures (85.62%), (89.69%) and (91.17) respectively. Results show that proposed graph-based word representations significantly improve the overall performance of CRF, SVM, and ensemble learning over traditional feature representation techniques. In general, results show that word representation is a key factor in constructing a suitable recognition method

Assessment of polyethylene degradation after aging through anaerobic digestion and composting

Impurities in bio-waste enter biogas and compost facilities during bio-waste treatment. The plastic fraction is usually separated and sent for incineration. This study is aimed at evaluating the quality of low density polyethylene after being exposed to anaerobic digestion, composting or both processes sequentially, in order to assess for the optimum post-processing of these plastic fractions, eventually undergoing recycling processes. The alteration in the polymer's quality was first analyzed by non-destructive optical methods, including FTIR, NIR, SEM and EDX. These tests were followed by thermal and mechanical properties' assessment. The surface of the specimens showed signs of degradation, yet the extent of the changes was microscopic. The FTIR and NIR spectra showed higher intensities for C-H bonds in treated samples, which might be an indication of shorter polymer's chain length and/or higher chain scissoring. FTIR showed weak transmission spectral changes at regions representing C-O and O-H bonds for anaerobically digested and sequentially anaerobically digested and composted samples, indicating the existence of oxidized products, which was confirmed by the EDX analysis, where slightly higher oxygen content on the surface of specimens underwent the anaerobic digestion process was observed. However, NIR spectra did not show conforming spectra. It was accordingly concluded that the oxidized products are contaminants (residues on the specimens' surfaces), which was as well confirmed by the DSC analysis. The thermal analysis indicated a decrease in the polymer's crystallinity after being treated, where the decrease effect was the highest by anaerobic digestion, however, the mechanical properties (including tensile strength, elastic modulus and strain at break) pointed out minor quality alteration in treated samples, especially for samples underwent both processes successively. Based on the provided assessment, the general properties of LDPE plastic specimens are acceptable to be recycled, even after undergoing accelerated aging conditions, such as anaerobic digestion and composting. Further analyses are needed to evaluate plastics with additives as well as bags and films

Decontamination and recycling of agrochemical plastic packaging waste.

Agrochemical containers shall undergo decontamination before being considered for recycling. This study provides an assessment on the feasibility of the triple-rinsing decontamination procedure, while evaluating the appropriateness of the material’s quality for recycling. To achieve the objectives of the study, (1) the effectiveness of the decontamination procedure was investigated; (2) containers´ long storage times and changes on the polymer´s structure were assessed; and (3) the quality of the recycled material was tested. Results showed that the triple-rinsing procedure was ineffective for the container´s complete decontamination, yet a further washing step – performed during the simulation of the recycling process – allowed for an improved degree of decontamination for recycling. Photo-oxidation imposed significant changes on the chemical structure of the polymer, where the active ingredient could be detected by FTIR, even after the application of rinsing and extraction. The chemical structure of the bulk material has not changed, indicating that the pesticide mobilization was only confined to the surface. The mechanical tests showed material quality appropriateness, where tensile strength values were within the suggested ranges, providing a possibility for further utilization of this material when appropriate decontamination is applied

Municipal Solid Waste Composition and Generation with Emphasis on Plastics in Nablus City, Palestine

The aim of this study was to characterize the municipal solid waste (MSW) in Nablus city in Palestine, while focusing on the plastic waste fraction. The plastic fraction—an environmentally problematic waste stream—was further characterized into the different polymer types and formats with the aim of suggesting feasible recovery and recycling solutions. Locally generated studies lack data about the recyclable fractions in the MSW and a thorough characterization of the plastic waste stream, although there is global action to minimize and optimally treat this waste fraction. The composition analysis was conducted by collecting 60 samples from five districts with different characteristics (e.g., income, density, level of education, building formats). The fraction of bio- and organic waste is significant in the collected MSW in Nablus, representing about 68% of the total MSW. The recyclables (paper and cardboard, glass, metals and plastics) amount to 27.4% of the generated MSW in the city. The plastic fraction (10.1%) is mainly composed of low-density polyethylene (LDPE) films (39.8%), polyethylene terephthalate (PET) bottles (21.9%), high-density polyethylene (HDPE) rigids (19.0%), and polypropylene (PP) rigids (11.5%), all of which are technologically recyclable. The polymer types and container formats indicated that the collected plastics originate mostly from packaging. The outcomes of this research indicate the need to implement a separate collection system for the organic waste fraction, which could be used to produce compost for the agricultural activities in the region. By having such a system, the dry recyclables (including plastics) can be easily recovered with less degree of contamination for recycling, helping the local recyclers to access cleaner materials. Furthermore, the state of Palestine lacks strict regulations for the end-of-life treatment of the different waste fractions; therefore, having clear guidelines and incentive systems will result in the minimization of the generated waste as well as better achievement of recovery and recycling targets. In addition, expertise, funding, public awareness, facilities, equipment and other provisions are currently lacking or inappropriate. In future, these factors must be addressed to enhance sustainable solid waste management

Development of a method to produce standardised and storable inocula for biomethane potential tests \u2013 Preliminary steps

In biomethane potential (BMP) tests, different sources and origins of inocula might cause significant variations in the tests\u2019 results, preventing from acquiring a harmonised and standardised evaluation of the different substrates. In this study, a method to produce standardised and storable inocula was elaborated. For the development of the different investigation steps a control sludge originated from a wastewater treatment plant was utilised. Freeze-drying was applied in the framework of this study as a long-term conservation method for the anaerobic inocula. In order to ensure a closed system with anaerobic conditions at all times, a test system was developed to allow accurate and representative mass-balance experiments. The test results demonstrated that inocula conservation and re-suspension in BMP tests is possible; the limit value of the expected methane yield of a positive and lyophilised reference-control, was reached. However, a lag phase of 7\u201310 days was obtained, possibly due to the damage of microorganisms as a consequence of the conservation process. Further investigations need to be carried out to optimise the conservation process of the produced inocula or an initial preparation phase should be considered to reduce the lag phase

Municipal solid waste composition and generation with emphasis on plastics in nablus city, Palestine

The aim of this study was to characterize the municipal solid waste (MSW) in Nablus city in Palestine, while focusing on the plastic waste fraction. The plastic fraction—an environmentally problematic waste stream—was further characterized into the different polymer types and formats with the aim of suggesting feasible recovery and recycling solutions. Locally generated studies lack data about the recyclable fractions in the MSW and a thorough characterization of the plastic waste stream, although there is global action to minimize and optimally treat this waste fraction. The composition analysis was conducted by collecting 60 samples from five districts with different characteristics (e.g., income, density, level of education, building formats). The fraction of bio- and organic waste is significant in the collected MSW in Nablus, representing about 68% of the total MSW. The recyclables (paper and cardboard, glass, metals and plastics) amount to 27.4% of the generated MSW in the city. The plastic fraction (10.1%) is mainly composed of low-density polyethylene (LDPE) films (39.8%), polyethylene terephthalate (PET) bottles (21.9%), high-density polyethylene (HDPE) rigids (19.0%), and polypropylene (PP) rigids (11.5%), all of which are technologically recyclable. The polymer types and container formats indicated that the collected plastics originate mostly from packaging. The outcomes of this research indicate the need to implement a separate collection system for the organic waste fraction, which could be used to produce compost for the agricultural activities in the region. By having such a system, the dry recyclables (including plastics) can be easily recovered with less degree of contamination for recycling, helping the local recyclers to access cleaner materials. Furthermore, the state of Palestine lacks strict regulations for the end-of-life treatment of the different waste fractions; therefore, having clear guidelines and incentive systems will result in the minimization of the generated waste as well as better achievement of recovery and recycling targets. In addition, expertise, funding, public awareness, facilities, equipment and other provisions are currently lacking or inappropriate. In future, these factors must be addressed to enhance sustainable solid waste management

Investigation of standardised and adapted inocula for biomethane potential tests

In biomethane potential (BMP) tests, different sources and origins of inocula might cause significant variations in the tests’ results, preventing from acquiring a harmonised and standardised evaluation of the different substrates. In this study, a method to produce standardised and storable inocula was elaborated. In anaerobic bioreactors, inoculum based on Dried Destined Grain Substrates (DDGS) pellets was initially produced as substrate under defined conditions. Freeze-drying was applied in the framework of this study as a long-term conservation method for the anaerobic inocula. In order to ensure a closed system with anaerobic conditions at all times, a test system was developed allowing accurate and representative mass-balance experiments. The test results demonstrated that inocula preservation and re-suspension in BMP tests is possible; the limit value of the expected methane yield of the positive and lyophilised DDGS-substrate- control, was reached. However, the lyophilized inoculum with DDGS as substrate showed a significant lower specific biogas production compared to the postive control. After the repeated addition of DDGS after 68 days of incubation, no lag phase was observed in biogas production in the lyophilized batch. In this case, a lower substrate degradation compared to the first step was observed. Therefore, further investigations are necessary to reduce the lag phase and to develop a two-stage BMP test in which the standardised and storable inoculum can be added at defined concentrations in capsule or tablet form