A techno-economic study of the recycling of mixed plastics to useful products

The techno-economic implications of recycling the components of mixed plastics waste have been studied in a two-part investigation: (a) An economic survey of the prospects for plastics recycling, the plastics waste arisings from retailing, building, automotive, light engineering and chemical industries have been surveyed by mans of questionnaires and interviews. This was partially successful and indicated that very considerable quantities of relatively clean plastics packaging was available in major department chains and household stores. The possibility of devising collection systems for such sources, which do not lead to any extra cost, have been suggested. However, the household collection of plastics waste has been found to be uneconomic due to high cost of collection, transportation and lack of markets for the end products. (b) In a technical study of blends of PE/PP and PE/PS which are found in admixture in waste plastics, it has been shown that they exhibit poor mechanical properties due to incompatibility. Consequently reprocessing of such unsegregated blends results in products of little technological value. The inclusion of some commercial block and graft copolymers which behave as solid phase dispersants (SPES) increase the toughness of the blends (e.g. EPDM in PE/PP blend and SBS in PE/PS blend). Also, EPDM is found to be very effective for improving the toughness of single component polypropylene. However, the improved Technical properties of such blends have been accompanied by a fast rate of photo-oxidation and loss of toughness due to the presence of unsaturation in SPD's. The change in mechanical properties occurring during oven ageing and ultra-violet light accelerated weathering of these binary and ternary blends was followed by a viscoelastonetric technique (Rheovibron) over 9,, wide range of temperatures, impact resistance at room temperature (20-41'G) and changes in functional groups (i.e. carbonyl and trans-1,4-polybutadiene). Also the heat and light stability of single and mixed plastics to which thiol antioxidants were bound to SPE1 segment have been studied and compared with conventional antioxidants. The long-term performance of the mixed plastics containing SPE1 have been improved significantly by the use of conventional and bound antioxidants. It is concluded that an estimated amount of 30000 tonnes/year of plastics waste is available from department chains and household stores which can be converted to useful end products. This justifies pilot-experiments in collaboration with supermarkets, recyclers and converters by use of low cost SPD's and additives designed to make the materials more compatible.

Nonlinear speech analysis algorithms mapped to a standard metric achieve clinically useful quantification of average Parkinson's disease symptom severity

The standard reference clinical score quantifying average Parkinson's disease (PD) symptom severity is the Unified Parkinson's Disease Rating Scale (UPDRS). At present, UPDRS is determined by the subjective clinical evaluation of the patient's ability to adequately cope with a range of tasks. In this study, we extend recent findings that UPDRS can be objectively assessed to clinically useful accuracy using simple, self-administered speech tests, without requiring the patient's physical presence in the clinic. We apply a wide range of known speech signal processing algorithms to a large database (approx. 6000 recordings from 42 PD patients, recruited to a six-month, multi-centre trial) and propose a number of novel, nonlinear signal processing algorithms which reveal pathological characteristics in PD more accurately than existing approaches. Robust feature selection algorithms select the optimal subset of these algorithms, which is fed into non-parametric regression and classification algorithms, mapping the signal processing algorithm outputs to UPDRS. We demonstrate rapid, accurate replication of the UPDRS assessment with clinically useful accuracy (about 2 UPDRS points difference from the clinicians' estimates, p < 0.001). This study supports the viability of frequent, remote, cost-effective, objective, accurate UPDRS telemonitoring based on self-administered speech tests. This technology could facilitate large-scale clinical trials into novel PD treatments.

Chemical studies of biologically useful molecules

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Towards Useful Overall Network Teletraffic Definitions

A detailed conceptual and a corresponding analytical traffic models of an overall (virtual) circuit switching telecommunication system are used. The models are relatively close to real-life communication systems with homogeneous terminals. In addition to Normalized and Pie-Models Ensue Model and Denial Traffic concept are proposed, as a parts of a technique for presentation and analysis of overall network traffic models functional structure; The ITU-T definitions for: fully routed, successful and effective attempts, and effective traffic are re-formulated. Definitions for fully routed traffic and successful traffic are proposed, because they are absent in the ITU-T recommendations; A definition of demand traffic (absent in ITU-T Recommendations) is proposed. For each definition are appointed: 1) the correspondent part of the conceptual model graphical presentation; 2) analytical equations, valid for mean values, in a stationary state. This allows real network traffic considered to be classified more precisely and shortly. The proposed definitions are applicable for every telecommunication system.

Retinal arteriolar diameter response to flicker light provocation - A useful marker for risk stratification in cardiovascular disease?

Purpose: To to evaluate the benefit of bilinear and linear fitting to characterize the retinal vessel dilation to flicker light stimulation for the purpose of risk stratification in cardiovascular disease. Methods: Forty-five patients (15 with coronary artery disease (CAD), 15 with Diabetes Mellitus (DM) and 15 with CAD and DM) all underwent contact tonometry, digital blood pressure measurement, fundus photography, retinal vessel oximetry, static retinal vessel analysis and continous retinal diameter assessment using the retinal vessel analyser (and flicker light provocation). In addition we measured blood glucose (HbA1c) and keratinin levels in DM patients. Results: With increased severity of cardiovascular disease a more linear reaction profile of retinal arteriolar diameter to flicker light provocation can be observed. Conclusion: Absolute values of vessel dilation provide only limited information on the state of retinal arteriolar dilatory response to flicker light. The approach of bilinear fitting takes into account the immediate response to flicker light provocation as well as the maintained dilatory capacity during prolonged stimulation. Individuals with cardiovascular disease however show a largely linear reaction profile indicating an impairment of the initial rapid dilatory response as usually observed in healty individuals

'It’d be useful, but I wouldn’t use it':barriers to university students’ feedback seeking and recipience

For feedback to be effective, it must be used by the receiver. Prior research has outlined numerous reasons why students’ use of feedback is sometimes limited, but there has been little systematic exploration of these barriers. In 11 activity-oriented focus groups, 31 undergraduate Psychology students discussed how they use assessment feedback. The data revealed many barriers that inhibit use of feedback, ranging from students’ difficulties with decoding terminology, to their unwillingness to expend effort. Thematic analysis identified four underlying psychological processes: awareness, cognisance, agency, and volition. We argue that these processes should be considered when designing interventions to encourage students’ engagement with feedback. Whereas the barriers identified could all in principle be removed, we propose that doing so would typically require – or would at least benefit from – a sharing of responsibility between teacher and student. The data highlight the importance of training students to be proactive receivers of feedback.

The isolation, characterization, and application of WRKY genes as useful molecular markers in tropical trees

The improvement of tropical tree crops using conventional breeding methods faces challenges due to the length of time involved. Thus, like most crops, there is an effort to utilize molecular genetic markers in breeding programs to select for desirable agronomic traits. Known as marker assisted breeding or marker assisted selection, genetic markers associated with a phenotype of interest are used to screen and select material reducing the time necessary to evaluate candidates. As the focus of this research was improving disease resistance in tropical trees, the usefulness of the WRKY gene superfamily was investigated as candidates for generating useful molecular genetic markers. WRKY genes encode plant-specific transcriptional factors associated with regulating plants' responses to both biotic and abiotic stress. ^ One pair of degenerate primers amplified 48 WRKY gene fragments from three taxonomically distinct, economically important, tropical tree crop species: 18 from Theobroma cacao L., 21 from Cocos nucifera L. and 9 from Persea americana Mill. Several loci from each species were polymorphic because of single nucleotide substitutions present within a putative non-coding region of the loci. Capillary array electrophoresis-single strand conformational polymorphism (CAE-SSCP) mapped four WRKY loci onto a genetic linkage map of a T. cacao F2 population segregating for resistance to witches' broom disease. Additionally, PCR primers specific for four T. cacao loci successfully amplified WRKY loci from 15 members of the Byttneriae tribe. A method was devised to allow the reliable discrimination of alleles by CAE-SSCP using only the mobility assigned to the sample peaks. Once this method was validated, the diversity of three WRKY loci was evaluated in a germplasm collection of T. cacao . One locus displayed high diversity in the collection, with at least 18 alleles detected from mobility differences of the product peaks. The number of WRKY loci available within the genome, ease of isolation by degenerate PCR, codominant segregation demonstrated in the F2 population, and usefulness for screening germplasm collections and closely related wild species demonstrates that the WRKY superfamily of genes are excellent candidates for developing a number of genetic molecular markers for breeding purposes in tropical trees. ^

Net-surplus as a useful tool to analyse financial information in co-op societies

This paper aims to analyse a sample of Galician co-ops to verify whether or not it is possible to deduce different financial behaviours among co-op partners from the amount of net-surplus. To this end, our study adds net-surplus to the variation registered in some account entries so that other residual incomes yielded by the co-op may be considered. The distribution of these revenues shows that partners do not usually choose to fully anticipate residual incomes. This reveals that some firms follow a positive net-surplus strategy, which is actually different from the null net-surplus strategy asserted by the classical financial theory. Furthermore, results show that differences between both strategies are statistically significant. This opens a path to future research on determinants explaining why co-op partners voluntarily renounce to anticipating these residual incomes. Such behaviour only arises when yearly accounts render a positive result, thereby making the accounting net-surplus a useful tool to analyse financial information in co-op societies.