Evaluation of mist flow characteristic and performance in Minimum Quantity Lubrication (MQL) machining

Minimum Quantity Lubrication (MQL) is an alternative method to supply the cutting fluid in the formation of mist. MQL has proven to reduce machining cost and increase machining performance. The effectiveness and the working principle of MQL are still questionable with very few explanations provided. The present study is conducted to investigate the performance of MQL technique with different combination of spray and machining parameters. The Phase Doppler Anemometry (PDA) was used to characterize the lubricant spray under different input pressure for various nozzle outlet diameter of 2.5 mm (OD25) and 3.0 mm (OD30). This device can measure the amount of droplet and size. From these results, the distance of the nozzle to the cutting tip can be estimated. The turning performance in terms of cutting force and cutting temperature was evaluated under three levels of cutting speed and two levels of feed rate and at a constant depth of cut. The result shows that the most suitable mist flow pattern during machining was the largest spray cone angle supplied under 0.4 MPa input air pressure. In addition, significant reduction of cutting force and cutting temperature were obtained when using OD30 nozzle at the nozzle distances of 6–9 mm and the input air pressure of 0.4 MPa

Thermomechanical Assessment of Plastic Deformation in Model Amorphous Polyamide/Clay Nanocomposites

In an effort to isolate the role of nanofiller independent of changes in polymer microstructure, we report the processing and characterization of model amorphous polyamide/clay nanocomposites. Analyses confirm fully amorphous character, no change in Tg or thermal stability, and a partially exfoliated structure. The tensile modulus, yield stress, and failure stress increase with the clay content, both in dried and conditioned samples. In contrast, failure strain decreases with increasing clay content in conditioned samples but is independent of clay content in dried samples. Concurrently, the conversion of mechanical work to heat during plastic deformation was studied using infrared thermography, with the heat of deformation estimated based on these results and compared to the work of deformation. These results allow us to quantify changes in deformation mechanism and to conclude that the presence of clay enhances the conversion of mechanical energy to heat in these materials

Determination of mist flow characteristic for MQL technique using particle image velocimetry (PIV) and computer fluid dynamics (CFD)

In recent years, minimum quantity lubrication (MQL) machining is regarded as a promising method for reducing machining cost and cutting fluid, while improving cutting performance. However the effectiveness and the working principle of MQL are still questionable with very few explanations provided. The aim of this study is to determine the optimum distance between the nozzle and tool tip and appropriate flow pattern of the mist flow for minimum quantity lubricant using Particle Image Velocimetry (PIV) and Computer Fluid Dynamic (CFD) for optimizing the spraying conditions thus reducing the lubricant consumption. The spray from the nozzle with outlet diameter of 2.5 mm is analysed using Particle Image Velocimetry (PIV) to measure the mist flow velocity and identify the flow pattern. The input pressure of 0.2, 0.3 and 0.4 MPa will be discharged throughout the experiment. Higher pressure produce more mass flow rate which helps in reducing the cutting force and cutting temperature efficiently and prolong tool life. Thus the appropriate distance can reduce lubricant consumption and increase the cooling and lubricating ability with best nozzle position. The applied distance increases the efficiencies of MQL applied during machining process

Uudenlaiset arvonluontimallit kiertotalouden muovipakkausekosysteemissä

The circular economy (CE) requires innovative solutions to meet the current challenges with plastic packaging in Finland. The aim of the thesis is to develop clarity and a better understanding of the stakeholders and their readiness to transition towards the CE, the value circles and business models within the plastic packaging ecosystem. There needs to be an alignment of the understanding and perceptions between the challenges and commercial interests of expert academic views and those of organizations and businesses. Novel collaboration and sustainable value creation are needed from the stakeholders. The transition from the fossil-based PET to the bio-based PEF plastic is examined through a framework for sustainable circular business model innovation. There is increasing consumer demand for more sustainable products (e.g. recyclable and reusable plastic packages and packages from new packaging materials) while public interest in climate change and environmental issues is spreading. At the same time there are gaps between the existing knowledge and real-world commercial interests and pressures of businesses and organizations in the plastic packaging ecosystem. Who are the key stakeholders in the ecosystems and what kind of value circles and flows exist? What kind of new CE business models will emerge in the ecosystems? Finding some answers to these questions from the key people working with these issues will open new possibilities for bridging the gap to find more fundamental and viable solutions. The thesis is based on qualitative research using the interview method with relevant literature review for a firm theoretical foundation. The theoretical base of the research leans on previous literature on the CE ecosystems, value creation, and plastics. The data set gathered with the academics and representatives from organizations and businesses is analysed and discussed. The findings demonstrate that the fundamental challenges of the transition from fossil-based PET to bio-based PEF as plastic packaging material are complex. The ecosystem is sensitive to many aspects from economic, social, technological, organizational, operational, process, policy, regulatory and statutory changes. This may have a major impact on ecosystems, and rate of change can be relatively slow depending on circumstances, which can also reverse rapidly. The main findings reveal that the plastic packaging ecosystem is fragmented and that the regulatory and market barriers are hindering many aspects of circularity. Finding new solutions for plastic packaging should involve ways to overcome the technological barriers that are currently in the way of scaling up the production cycles.Kiertotalous edellyttää innovatiivisia ratkaisuja nykyisiin muovipakkausten haasteisiin Suomessa. Pro gradu -tutkielman tarkoituksena on tutkia muovipakkausekosysteemin sidosryhmiä ja niiden valmiuksia kiertotalouteen, sekä ymmärtää nykyisiä arvokiertoja ja liiketoimintamalleja. Akateemiset näkemykset yhdessä organisaatioiden ja yritysten näkemysten kanssa ekosysteemin haasteista ja kaupallisista eduista tulee yhtenäistää. Sidosryhmiltä vaaditaan uudenlaista yhteistyötä ja kestävää arvonluontia. Muutosta fossiilipohjaisesta PET-muovista biopohjaiseen PEF-muoviin tarkastellaan kiertotalouden viitekehyksen avulla. Kuluttajien kysyntä ekologisesti kestävämmille tuotteille kasvaa, (mm. uudelleenkäytettävät muovipakkaukset ja pakkaukset uusista materiaaleista), kun yleinen kiinnostus ilmastonmuutokseen ja ympäristöasioihin lisääntyy. Samanaikaisesti muovipakkausten ekosysteemissä on aukkoja olemassa olevan tiedon ja yritysten ja organisaatioiden reaalimaailman kaupallisten etujen ja paineiden välillä. Mitkä ovat muovipakkausekosysteemien keskeisimmät sidosryhmät, ja millaisia arvokiertoja ja -virtauksia on olemassa? Millaisia uusia kiertotalouden liiketoimintamalleja voi syntyä muutoksessa fossiilipohjaisesta muovista biopohjaiseen muoviin? Tutkielma täydentää aiempaa tutkimusta vastaamalla näihin kysymyksiin koskien nykyistä muovipakkausekosysteemiä Suomessa. Metodologia perustuu kvalitatiiviseen tutkimukseen, ja aineiston keruun menetelmänä asiantuntijoita sekä pakkausekosysteemin eri sidosryhmiä haastatellaan puolistrukturoiduilla haastatteluilla, joiden tulokset analysoidaan ja käsitellään. Tutkielman teoreettinen perusta nojaa aiempaan tutkimukseen kiertotalouden ekosysteemeistä, arvon muodostuksesta sekä muoveista. Tutkielman tulokset osoittavat, että fossiilisesta PET:stä biopohjaiseen PEF-muovipakkausmateriaaliin siirtymisessä on merkittäviä ja monimutkaisia haasteita. Ekosysteemi on herkkä taloudellisille, sosiaalisille, teknologisille, organisatorisille, toiminnallisille, prosessi-, politiikka-, sääntely- ja lakimuutoksille. Niiden vaikutus ekosysteemiin voi olla voimakas, ja muutosnopeus voi olla suhteellisen hidas riippuen olosuhteista, jotka voivat myös muuttua nopeasti. Päätulokset osoittavat, että muovipakkausekosysteemi on pirstaloitunut, ja sääntely sekä markkinoiden luomat rajoitukset ovat kiertotalouden kehittymisen hidasteena. Tuotantomäärien kasvattaminen vaatii teknologista kehitystä, jotta uudet muovipakkausratkaisut saavat jalansijaa markkinoilla

Cyber Security in Modern Agriculture. Case Study: IoT-based Insect Pest Trap System

A simple traditional insect pest trap system is transformed by Internet of Things (IoT for short) into an advanced connected device. The benefits are immense but cyber security imposes a great threat. The goal is to develop a checklist of requirements for developers of IoT-augmented traps that are alert to the challenges. The initial joy of creating prototypes using IoT in an end-to-end system is an achievement that needs to be reinforced with good knowledge of cyber security Theory about the use of IoT in agriculture is comprehensive; technical details, architectural descriptions and general uptake of modern ICT is vast. Still, there are gaps and some neglect from a practical angle on the requirements to develop IoT prototypes for ensuring system continuity.; a shortcoming that is addressed here. There is a need to study the cyber security requirements for a development project of an IoT-based insect pest trap monitoring system. Guidance is needed to assist developers with limited cyber security knowledge to understand and be aware of threat scenarios and mitigation efforts to minimize the potential cyber-attacks. Using a case study involving a combination of investigating the IoT modules used in the field experiment prototypes’ and related literature review, concrete guidance is developed. The fundamental principles of developing a proper business case and requirements apply equally to the insect pest project as any other project implementation. Basic cyber security knowledge is essential for developers including awareness of regular IoT news. The contemporary cyber security and IoT environment within the agriculture sector is dynamic and evolving rapidly with modern technology. The significance of this study is that it informs about theoretical understanding of IoT and cyber security and gives practical guidance to developers on how to be diligent about the fundamentals

Development of a method for accurate and objective neurological tremor analysis

A method that allows for quantitative analysis of simulated tremor has been developed. The technique can complement the qualitative analysis carried out by physicians in tremor diagnosis of Parkinson patients.Master of Science (Biomedical Engineering

IOT-teknik för uppföljning av skadegörare

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IOT-teknik för uppföljning av skadegörare

201