Search results for "PRI"
showing 10 items of 17196 documents
3D cultures of primary astrocytes on Poly-L-lactic acid scaffolds
Tissue engineering is an emerging multidisciplinary field that aims at reproducing in vitro tissues with morphological and functional features similar to the biological tissue of the human body. Polymeric materials can be used in contact with biological systems in replacing destroyed tissue by transplantation [1]. Several biopolymers, including poly L (lactic acid) (PLLA), have been used in biomedical applications to set scaffolds with ductile proprieties and biodegradation kinetics [2]. In particular, the PLLA scaffold topography mimics the natural extracellular matrix and makes it a good candidate for neural tissue engineering. We report about of 3D system the PLLA porous scaffolds prepar…
3D printeru apkalpojošā personāla ķīmiskie un fizikālie darba vides riski
2018
“3D drukāšanas iekārtu apkalpojošā personāla ķīmiskie un fizikālie darba vides riski”. Darba autore: Anete Bušmane. Zinātniskā vadītāja: Dr.chem. Elīna Pajuste. Darba apjoms ir 64 lpp., tajās ietvertas 9 tabulas, 26 attēli, 1 pielikums un 42 literatūras avoti. 3D drukas nozarē no digitāla formāta tiek izdrukāts reāls un aptaustāms objekts, šī nozare līdz šim maz izpētīta ne tikai Latvijā, bet visā pasaulē. Galvenie faktori uz kuriem tiek vērsta uzmanība zinātniskajos rakstos un pētījumos, ir par nozarē sastopamajiem ķīmiskajiem un fizikālajiem riska faktoriem. Zinātnisko pētījumu šajā jomā nav daudz, un tie kas šobrīd ir pieejami nav ar viennozīmīgu informāciju, Latvijā šī nozare līdz šim n…
Green Composites Based on PLA and Agricultural or Marine Waste Prepared by FDM
2021
Three dimensional-printability of green composites is recently growing in importance and interest, especially in the view of feasibility to valorize agricultural and marine waste to attain green fillers capable of reducing bioplastic costs, without compromising their processability and performance from an environmental and mechanical standpoint. In this work, two lignocellulosic fillers, obtained from Opuntia ficus indica and Posidonia oceanica, were added to PLA and processed by FDM. Among the 3D printed biocomposites investigated, slight differences could be found in terms of PLA molecular weight and filler aspect ratio. It was shown that it is possible to replace up to 20% of bioplastic …
P3HT plānu kārtiņu īpašību pētījumi 3D printētu termoelektrisko ierīču pielietojumiem
2019
Šajā darbā tika veikti pētījumi ar poli (3-heksiltiofēna) (P3HT) plānajām kārtiņām ar mērķi novērtēt šī materiāla pielietojamību 3D printētās termoelektriskās ierīcēs. Darbā tika pētītas tīras dažādu polimerizāciju pakāpes P3HT plānās kārtiņas un kārtiņas, kas ir dopētas ar (2,3,5,6-Tetrafluoro-2,5-cikloheksadiēn-1,4-dilidēn)-dimalonodinitrilu (F4TCNQ). Šīm kārtiņām tika noteikta elektrovadītspēja, Zēbeka koeficienti kā arī jaudas faktora vērtības. Lai varētu novērtēt šo vielu pielietojamību 3D printēšanai, to veidotās plānās kārtiņas tika karsētas un noteikti to raksturojošie koeficienti pēc katras karsēšanas. Šī karsēšana simulē apstākļus, kādiem tiktu pakļauti materiāli 3D printēšanas pr…
Topoloģijas optimizācijas algoritmi 3D printējamu struktūru dizainam
2017
Darbs "Topoloģijas optimizācijas algoritmi 3D printējamu struktūru dizainam" ir veltīts topoloģijas optimizācijas algoritmu un 3D printeru funkcionalitātes izpētei. Darbā tiek apskatīti divi topoloģijas optimizācijas algoritmi un to pielietojumi vairākos piemēros. Ir veikta plaša izpēte par 3D printeru tehnisko specifikāciju, to darbību un izmantošanas veidiem. Darba galvenais mērķis ir realizēt topoloģijas optimizācijas algoritmu no uzdevuma formulējuma līdz pat gatavai, izdrukātai detaļai. Darbā ir apskatīti 3D struktūru nepieciešamie izveides nosacījumi, to modelēšana ar topoloģijas optimizāciju, kā arī pats drukāšanas process. Darba rezultātā tika iegūts dzelzceļa tilta posms, kurš vēlā…
PLLA scaffolds with controlled architecture as potential microenvironment for in vitro tumor model
2019
Abstract The "microenvironment" where a tumor develops plays a fundamental role in determining its progression, the onset of metastasis and, eventually, its resistance to therapies. Tumor cells can be considered more or less invasive depending both on the nature of the cells and on the site where they are located. Commonly adopted laboratory culture protocols for the investigation of tumor cells take usually place on standard two-dimensional supports. However, such cultures do not allow for reproduction of the biophysical properties of the tumor’s microenvironment, thus causing the cells to lose most of their relevant characteristics. In this work MDA-MB 231 breast cancer cells were cultiva…
Microstructural characterization of a 3D-printed soil
2022
Transversal applications of 3D-printing (or Additive Manufacturing) have been recently implemented in the field of Geomechanics. In a 3D-printing process, the printed volume is obtained from successive layering of adjacent soil filaments. In this work, the fabric of an as-printed soil has been carried out by combining Mercury Intrusion Porosimetry (MIP) tests and Scanning Electron Microscope (SEM) observations, with the aim to highlight how the particle arrangements and the orientation and shape of pores are linked to the printing operation. The microstructural analyses showed that macropores are the result of the relative position of the filaments and their initial distortion in quasi-undr…
Design challenges and opportunities of 3D printing
2019
In the future, the number and complexity of products made using additive manufacturing (AM) techniques will increase rapidly. The development of softwares and algorithms related to processes will eliminate extra intermediate steps between the product design and the end product, and will finally give us more intelligent way to manufacture these new products. More efficient 3D printing processes will enable the production of cheaper individual items and, furthermore, they will increase the demand for these high - quality tailored unrivalled solutions. The market potential is huge. However, at present the fundamentals of the area are only lightly studied and several key challenges concerning s…
The emerging role of 3D printing in the fabrication of detection systems
2021
Abstract 3D printing is fast evolving as an additive manufacturing technique that has been adopted in (bio)analytical science because of the ample variety of materials and technologies currently available for highly affordable prototyping. This review focuses on the unique characteristics of 3D printing for manufacturing of optical and electrochemical detection systems, and sampling interfaces for analytical purposes using fused deposition modelling, vat polymerization (stereolithography and digital light processing) and photopolymer inkjet printing. The majority of works surveyed within the time span of mid-2018 to mid-2020 encompassed the fabrication of several components of the detection…
Porous 3D Printed Scavenger Filters for Selective Recovery of Precious Metals from Electronic Waste
2018
Selective laser sintering (SLS) 3D printing is used to fabricate highly macroporous ion scavenger filters for recovery of Pd and Pt from electronic waste. The scavengers are printed by using a mixture of polypropylene with 10 wt% of type‐1 anion exchange resin. Porosities and the flow‐through properties of the filters are controlled by adjusting the SLS printing parameters. The cylinder‐shaped filters are used in selective recovery of Pd and Pt from acidic leachate of electronic waste simply by passing the solution through the object. Under such conditions, the scavenger filters are able to capture Pd and Pt as anionic complexes with high efficiency from a solution containing mixture of dif…