ARTICLE | doi:10.20944/preprints202208.0328.v1
Subject: Engineering, Mechanical Engineering Keywords: thin-film sensors; foil sensors; composite structures; structural bonding; multifunctional bondline; function conformity; sensor integration; structural health monitoring
Online: 18 August 2022 (03:41:32 CEST)
We present an integrable, sensor inlay for monitoring crack initiation and growth inside bondlines of structural carbon fiber reinforced plastic (CFRP) components. The sensing structures are sandwiched between crack stopping polyvinyliden fluoride (PVDF) and a thin reinforcing polyetherimide (PEI) layer. Good adhesion at all interfaces of the sensor system and to the CFRP material is crucial as weak bonds can counteract the desired crack stopping functionality. At the same time, the chosen reinforcing layer must withstand high strains, safely support the metallic measuring grids and possess outstanding fatigue strength. We show that this robust sensor system, which measures the strain at two successive fronts inside the bondline, allows to recognize cracks in the proximity of the inlay regardless of the mechanical loads. Feasibility is demonstrated by static load tests as well as cyclic long-term fatigue testing with up to 1,000,000 cycles. In addition to pure crack detection, crack distance estimation based on sensor signals is illustrated. The inlay integration process is developed with respect to industrial applicability. Thus, implementation of the proposed system will allow the potential of lightweight CFRP constructions to be better exploited by expanding the possibilities of structural adhesive bonding.
ARTICLE | doi:10.20944/preprints201811.0002.v1
Subject: Social Sciences, Economics Keywords: Agricultural ExternalitiesPublic GoodsSustainable Agricultural Development Multifunctional Agriculture
Online: 1 November 2018 (18:31:26 CET)
The agriculture and rural areas perform a new function which requires the delivery of public goods to the society. In turn, a comprehensive identification and analysis of agricultural externalities (external economies) involves a need for developing a dedicated valuation methodology. This paper presents the assumptions of the public goods theory and puts them in the context of agriculture. The study focuses on analyzing the valuation methods for external economies, and proposes a methodology for the valuation of some illustrative positive externalities of agricultural production and of natural environment resources regarded as public goods (the agri-tourist value of a farm and the value of a natural waterhole).
ARTICLE | doi:10.20944/preprints202107.0708.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: landscape design and planning; research-by-design; multifunctional agriculture
Online: 30 July 2021 (15:49:35 CEST)
Rural landscapes all over the world are subject to great transformations, first of all the continuous and slow depopulation of land and villages. It is a dramatic phenomenon that causes devastating consequences for environmental systems and for the tangible and intangible heritage of entire territories. The situation becomes more ambiguous when it comes to cultural landscapes, especially those internationally recognized as exceptional (i.e. inscribed on the UNESCO World Heritage List). In this case, the risk is to abandon agricultural production in favor of consumerist tourist economies, which can damage the territorial authenticity. In this paper we question the role of the landscape project in strengthening territorial resilience. In particular, a composite and interdependent action is proposed between landscape design and implementation of a multifunctional agriculture model, oriented towards teaching and tourism. To undertake this investigation, a master's thesis work on Landscape Architecture is examined, as an opportunity for a research-by-design method. The application case is the Italian UNESCO site of Vignale Monferrato, a depopulated rural village, characterized by abandoned land and buildings. The paper concludes by outlining replicability application scenarios for the proposed model.
ARTICLE | doi:10.20944/preprints201810.0502.v2
Subject: Chemistry, Other Keywords: Keywords: Multifunctional polymeric materials; polysilanes; chiral polymers; photoactive polymers.
Online: 26 October 2018 (12:10:41 CEST)
Now-a-days, the thrust area of materials’ research is to develop multifunctional materials, which have multiple properties in a single functional material. We are interested to develop multifunctional polysilanes having special functional properties such as optical activity and photoluminescence (PL) properties. In this investigation, poly(methyl phenyl silane) (PMPS) was integrated with a chiral unit and a photoactive unit by in situ photopolymerization of (R)-N-(1-phenyl ethyl) methacrylamide (R-NPEMAM) and disperse red 1 methacrylate (DR1MA) monomer in the presence of PMPS. PMPS acted as a macrophotoinitiator and by UV exposure it produced macroradicals which initiated polymerization of chiral and photoactive monomers. Thus a block copolymer of PMPS-b-(R-NPEMAM-ran-DR1MA) was synthesized.The synthesized multifunctional organic inorganic hybrid polymer samples were characterized by FTIR and NMR spectroscopy. The molecular weights of the samples were measured by GPC analysis. The optical, chiroptical and photoluminescence properties were studied. The narrow band at about 1638 cm-1 is due to C=O stretching vibration of -CONH- of the chiral unit. A wide absorption peaks at 3444 cm-1 is the characteristic of NH trans stretching vibration of secondary amide group. The asymmetric stretching of NO2 group appeared at 1481 cm-1 and the characteristic peak at 1427 cm-1 was observed due to azo (-N=N-) group stretching of DR1MA unit. The Si-Si band of PMPS appeared at about 462 cm-1 in FTIR spectra. The optical absorbance observed at 272 nm is due to π-π* transition of aromatic ring and at 330 nm corresponds to σ-σ* transition of Si-Si bond. The other electronic absorption observed in the visible region at 475 nm corresponds to the combined contribution of n-π* and π-π* transition of DR1MA unit. The photoluminescence properties of such polymers were studied for the variation of concentration of the polymer solution and variation with excitation energy such as 275 nm, 325 nm and 475 nm in THF solvent. Such synthesized multifunctional photoactive organic-inorganic polymers having unusual optical, chiroptical and photoluminescence property may find novel optoelectronic (friend foe identification and secretive code identification) applications.
REVIEW | doi:10.20944/preprints202102.0449.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: multifunctional; hydrogel nanocomposties; tissue engineering; drug delivery; wound healing; bioprinting; biowearable devices
Online: 22 February 2021 (08:48:20 CET)
Hydrogels are used for various biomedical applications due to their biocompatibility, capacity to mimic the extracellular matrix, and ability to encapsulate and deliver cells and therapeutics. However, traditional hydrogels have a few shortcomings, especially regarding their physical properties, thereby limiting their broad applicability. Recently, researchers have investigated the incorporation of nanoparticles (NPs) into hydrogels to improve and add to the physical and biochemical properties of hydrogels. This brief review focuses on papers that describe the use of nanoparticles to improve more than one property of hydrogels. Such multifunctional hydrogel nanocomposites have enhanced potential for various applications, including tissue engineering, drug delivery, wound healing, bioprinting and biowearable devices.
ARTICLE | doi:10.20944/preprints201901.0280.v1
Subject: Physical Sciences, Optics Keywords: thin film crystal growth; epitaxial layer growth; multifunctional borate crystals; planar optical waveguides
Online: 28 January 2019 (12:20:05 CET)
We investigated fabrication of neodymium doped thin film optical waveguide-based devices as potential active sources for planar integrated optics. Liquid-phase epitaxial growth was used to fabricate neodymium-doped yttrium aluminum borate films on compatible lattice-matched un-doped yttrium aluminum borate substrates. We observed the refractive index contrast of the doped and un-doped crystal layers by differential interference contrast microscopy. In addition, characterization by X-ray powder diffraction, optical absorption and luminescence spectra demonstrated the crystal quality and uniformity and optical guiding of the resulting thin films.
ARTICLE | doi:10.20944/preprints202201.0410.v1
Subject: Chemistry, Physical Chemistry Keywords: multifunctional microcarriers; curcumin; decorated poly(acrylic acid); layer-by-layer (LbL) deposition; antimicrobial function
Online: 27 January 2022 (11:01:46 CET)
The design of multifunctional microcarriers has attracted significant attention because they combine various functions within a single system. In this study, we developed a set of multi-layered hydrogel microcarriers, which were first loaded with chemotherapeutic curcumin (CUR), then using the layer-by-layer (LbL) technique, coated through a polyelectrolyte shell consisting of chitosan (CHIT) or poly(allylamine hydrochloride) (PAH). As an outer layer with antimicrobial function, newly synthesised alkylene quaternary ammonium salt functionalised polyelectrolytes (A-QAS-PEs) were applied. For this purpose, poly(acrylic acid) (PAA) was decorated with dif-ferent hydrophobic side chains (n-hexane and n-dodecane side entities) and different degrees of substitution (m) of quaternary ammonium groups (abbreviated as PAA-C(O)O-(CH2)n-N+(CH3)3(m); n=6,12; m=8-14%). The grafting approach of PAA with the al-kylene quaternary ammonium salt moiety was performed under mild reaction conditions using Steglich esterification followed by quaternisation. The structure of antimicrobial decorated PAA was confirmed by 1H NMR and FTIR, and the mean diameter of all multifunctional microparticles was characterised by SEM. The viscoelastic properties of the functional layers were studied using QCM-D. The release of CUR from the microcarriers was described using a hybrid model, i.e., a combination of first-order kinetics and the Korsmeyer-Peppas model. The antimicrobial activity of functionalised PAA and multilayered CUR-loaded hydrogel microcarriers with quaternary am-monium function was assessed against Staphylococcus aureus and Serratia marcescens by the agar diffusion assay method. Only a limited inhibition zone of PAA was observed, but in the case of both antimicrobial decorated PAA and the corresponding multilayered nanocarriers, the inhibi-tory activity increase was achieved against both strains of bacteria.
ARTICLE | doi:10.20944/preprints201704.0140.v1
Subject: Social Sciences, Other Keywords: common lands; baldios; wild mushrooms; non-timber forest products; Portugal; multifunctional forestry; community; community forestry; local values; forest governance
Online: 21 April 2017 (12:18:11 CEST)
Forest community connections are crucial to ensure forest stewardship and sustainability. We set to explore the potential of mushrooming to enable such connections in contexts were these were historically broken, alienating local people from forests. Taking the case of the recent devolution of a community forest in central Portugal (baldios) to the local population, the authors present a five-year pilot project to rework mycology from a mushroom-centered approach to a mushroom-in-baldios approach. Mushrooms were used as an entry-point to connect the forest ecology with the challenges of governance and community building. The devised activities provided an opportunity for people inside and outside the local community to adventure into the woods, find about their socio-ecological history, develop communal and convivial relationships and engage in the responsible gathering of wild mushrooms. However, the hosting of mushroomers to know, value and engage with the community forest recovery is constantly worked against the enclosure of mushrooms to provide marketable forms of leisure. The outcome will depend on the relationships established between mushrooms, mycologists, local administrators, commoners and poachers, operating within a framework that favors the eradication of resources instead of the long-term relationships that sustain places.
ARTICLE | doi:10.20944/preprints202103.0059.v1
Subject: Life Sciences, Biochemistry Keywords: Metallothionein (MT); Scientific discovery; Scientific pursuit; Research strategies; upward looking research; Exploratory research; Protein function; Compensation; Moonlighting; multifunctional proteins; Vestiges
Online: 2 March 2021 (09:39:39 CET)
In the mid-1950s, Bert L. Vallee and his colleague Marvin Margoshes discovered a molecule known today as metallothionein (MT). Meanwhile MTs have been shown to be common in many biological organisms. Despite their prevalence, however, it remains unclear to date what exactly MTs do and how they contribute to the biological function of an organism or organ. Honoring Dr. Vallee’s sometimes innovative approach to research, this contribution sets out to show how philosophy of science can help us gain a clearer picture of biochemical research. We shall look into both the discovery of as well as recent research on Dr. Vallee’s beloved family of MT proteins to illustrate (i) how exploratory and upward-looking research play important roles in biochemical discoveries although they do not fit the paradigmatic approach of decomposition and struc-ture-function mapping. Besides, we shall suggest (ii) that while other biochemical molecules ex-hibit a clearly identifiable function, other research hypotheses might be worthy of pursuit in the case of MTs.