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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A survey of the cylinder machine boxboard industry

Rohde, Charles N. January 1965 (has links)
Thesis (M.B.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01
2

The use of a char pile reactor to study char bed processes

Aiken, Gregg W. 11 June 1988 (has links)
No description available.
3

Återvinning av dryckeskartonger : En studie som syftar till att öka återvinningsgraden av Tetra Paks förpackningar i Indonesien / Recycling of beverage cartons : Increasing Tetra Paks recycling rate in Indonesia

Backlund, Per January 2014 (has links)
People of the modern world consume more than they ever used to do. Because of the close correlation between consumption and the amount of waste, the waste volume is also expected to increase. The purpose of this study is to examine if some measures in the recycling process from Sweden could be implemented in Indonesia. In fact, Indonesia is one of the countries in which the waste management system is struggling. Tetra Pak, one of the world leading producer of food packaging, is studied in this report. Tetra Paks recycling rate of their beverage cartons is relatively low, 8.42 %, in Indonesia compared with their recycling rate in other countries. To answer the purpose, information was collected from scientific reports, by interviews carried out in both Sweden and Indonesia and by study visits in Indonesia. The results of the study shows that there are measures which could be made in the recycling process to increase the recycling rate in Indonesia. School projects and deposit systems could increase the collection rate and a drumscreen and a buffertank could make the recycling process more profitable for the papermills. There is also some alternative end products which could make the whole recycling process more public visible. One of the conclusions of this study is that the paper mills should adjust their drumscreens, this to increase the fibre yield which is crucial for the recycling value. Another conclusions is that Tetra Pak should consider to initiate a recycling business by their own, in order to reduce the burden on the environment.
4

Prediction of Plastic Fragments in Recycled Paper Using Near-Infrared Spectroscopy

Alieva, Fidan January 2023 (has links)
Sustainability has gained a lot of attention in the field of research. Researchers and consumers both prioritize sustainability and environmental issues over previously dominant materials, such as plastic. Packaging and disposable items that used to be made of plastic have largely been replaced with paper. Unfortunately, paper does not perform as well as plastic regarding barrier properties against grease, oxygen, or water vapor. Barrier properties are an important factor when choosing packaging material for food, among other things, as they help maintain the shelf life of the product. In order to improve the properties of the paper packaging and expand its use, the paper is coated with a polymer. However, the polymer contributes to challenges in the recycling of the products as some of the polymer attaches to the fibers, causing difficulties in the separation of each material. Small fragments of plastic may end up in the material streams and the recycled pulp due to the existing challenges in completely removing plastic from cellulosic substrates during recycling. This thesis analyzes the possibilities of identifying and classifying plastic fragments of polyethylene (PE) and polyvinyl alcohol (PVOH) in recycled paper sheets using near-infrared spectroscopy together with multivariate data analysis. The purpose of the work is to develop models that can identify possible residues that may appear in recycled products from various industries. Paper sheets of two different grammages and six different compositions of recycled fiber and virgin fiber were created and scanned by NIR, with and without plastic film under the sheets. The scans were used to develop classification models to identify and categorize scans not included in the calibration data set. The performance of the models was tested by applying them to images of sheets of paper with plastic fragments of different sizes and different type underneath. The results indicated potential in the method. The prediction of the paper sheets with a lower grammage was mostly correct, whereas the classification of polyethylene showed the best performance. There was some noise in the prediction of the plastic fragments, regardless of the grammage of the paper. The noise may be due to a wide variation in the calibration data set since it consisted of paper sheets of six different compositions. A large part of the noise was incorrectly classified as polyvinyl alcohol, which can be due to differences in the manufacturing process of the plastic films. The conclusion of the thesis is that it is feasible to identify and categorize plastic fragments of polyethylene and polyvinyl alcohol in recycled paper sheets with a certain margin of error. It can be stated that the method shows promise, but further research and development in the field is required to build models that can be applied to a wider range of samples.

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