78 research outputs found
Quando lo sfruttamento è smart
No full textThe essay examines the ways in which work is used in digital plat. forms. The author proposes to define "smart exploitation" the specific characteristics of the use of work by digital platforms such as Uber. El ements are identified, such as algorithmic management, datification and gamification, highlighting that the freedom of gig workers actually hidks a form of self-exploitation induced by the technical operating models of the platforms themselves. The "smart exploitation" therefore alludes to a
model of technoregulation that promotes the fake self-employment of gig workers
Investigation of electronic structure and chemical bonding of intermetallic Pd2HfIn: An ab-initio study
No full textLa libera circolazione comunitaria di servizi labour intensive
No full textThe Author assumes that the liberalization of the services in the Eu has a direct impact on national labour law. This thesis is illustrated, on one hand, clarifying the concept of "service" in the Ec Treaty and in the Italian legal system. On the other hand, the essay underlines as, in many cases, the provision of services is characterized by a labour intensive nature. In this sense the cross-border service provision makes the transnational workers mobility (posting) possible but, at the same time, it affects legal and contractual provision concerning employment conditions applicable in the host Member States. Finally, it is highlighted how the development of the internal market for services may generate risks of social dumping and regulatory competition among Member States
Studying the role of noise in E. coli chemotaxis
No full textBiochemical signaling networks allow living cells to adapt to changing environments, but these networks have to cope with unavoidable number fluctuations (“noise”) in their molecular constituents. These fluctuations can arise over time in an individual cell (due to inherent stochasticity in chemical reactions) or manifest themselves as differences between individual cells. The chemotaxis signaling network of Escherichia coli, using which these bacteria modulate their random walk-like run/tumble swimming pattern to navigate their environment, is a paradigm for the role of noise in cell signaling. The E. coli chemotaxis network thus has been my model system of choice to characterize and study the role of these different types of noise.
A key signaling protein in this network, CheY, when activated by phosphorylation, causes a switch in the rotational direction of the flagellar motors propelling the cell, leading to tumbling. Since the degree of CheY activation/phosphorylation is a function of the cell’s environment, the CheY-P concentration, [CheY-P], is a measure of the output of the chemotaxis network and random fluctuations in [CheY-P] in time provide a proxy for network noise. However, measuring these fluctuations in the single cell, especially at the relevant timescale of individual run and tumble “decision making” events, remains a challenge. In my thesis work, we developed an approach to quantify short timescale (0.5-5 s) network noise due to [CheY-P] fluctuations using rotational switching statistics of individual flagella observed using time-resolved fluorescence microscopy of individual optically trapped E. coli cells. This work revealed the existence of high network noise at steady state which may be critical to driving cell tumbling. Upon activation of the network, this noise is reduced dramatically; we connect this reduction, through modeling, to the existence of an intrinsic kinetic ceiling on network activation, which may be functionally important to prevent unproductive tumbling.
In collaboration with the research groups of Seppe Kuehn, Ido Golding and Nigel Goldenfeld, using single-cell optical trapping, I also studied evolution in E. coli motility/chemotaxis and the cell-cell variation therein in strains that were selected for faster collective migration through agar. In this work, we attempt to connect changes in relevant molecular constituents of the chemotaxis network, CheR and CheB, to changes in motility and chemotaxis at the individual and population level.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2022-12-01The student, Roshni Bano, accepted the attached license on 2020-11-28 at 12:06.The student, Roshni Bano, submitted this Dissertation for approval on 2020-11-28 at 12:18.This Dissertation was approved for publication on 2020-12-03 at 16:25.DSpace SAF Submission Ingestion Package generated from Vireo submission #15973 on 2021-03-04 at 16:32:37Made available in DSpace on 2021-03-05T21:45:38Z (GMT). No. of bitstreams: 2
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Previous issue date: 2020-12-03Embargo set by: Seth Robbins for item 117309
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Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 117309
Lift date: 2023-03-05T21:47:41Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemAuthor requested closed access (OA after 2yrs) in Vireo ETD systemLimite
Interfacial Coupling Effect on Electron Transport in MoS2/SrTiO3 Heterostructure: An Ab-initio Study
No full textAbstractA variety of theoretical and experimental works have reported several potential applications of MoS2 monolayer based heterostructures (HSs) such as light emitting diodes, photodetectors and field effect transistors etc. In the present work, we have theoretically performed as a model case study, MoS2 monolayer deposited over insulating SrTiO3 (001) to study the band alignment at TiO2 termination. The interfacial characteristics are found to be highly dependent on the interface termination. With an insulating oxide material, a significant band gap (0.85eV) is found in MoS2/TiO2 interface heterostructure (HS). A unique electronic band profile with an indirect band gap (0.67eV) is observed in MoS2 monolayer when confined in a cubic environment of SrTiO3 (STO). Adsorption analysis showed the chemisorption of MoS2 on the surface of STO substrate with TiO2 termination which is justified by the charge density calculations that shows the existence of covalent bonding at the interface. The fabrication of HS of such materials paves the path for developing the unprecedented 2D materials with exciting properties such as semiconducting devices, thermoelectric and optoelectronic applications.</jats:p
Effect of Nb doping on electron transport mechanism of CrSi2: A first-principles investigation
No full textCoexistence of Rashba Effect and Spin-valley Coupling in TiX2 (X= Te, S and Se) based Heterostructures
No full textSpin-orbit coupling (SOC) combined with broken inversion symmetry play key
roles in inducing Rashba effect. The combined spontaneous polarization and
Rashba effect enable controlling a material's spin degrees of freedom
electrically. In this work we investigated the electronic band structure for
several combinations of TiX2 monolayers (X= Te, S and Se): TiTe2/TiSe2,
TiTe2/TiS2, and TiSe2/TiS2. Based on the observed orbital hybridization between
the different monolayers in these hetero-structures (HSs), we conclude that the
most significant Rashba splitting occurs in TiSe2/TiS2. Subsequently, we used
Fluorine (F) as an adatom over the surface of TiSe2/TiS2 at hollow and top
sites of the surface to enhance the Rashba intensity, as the F adatom induces
polarization due to difference in charge distribution. Furthermore, by
increasing the number of F atoms on the surface, we reinforced the band
splitting, i.e., we observe Rashba splitting accompanied by Zeeman splitting at
the valence-band edge states. Berry curvatures at K and K' with equal and
opposite nature confirms the existence of valley polarization. The
computationally observed properties suggest that these HSs are promising
candidates for spin-valley Hall effect devices and other spintronic
applications
Investigation of strain effect on electronic, chemical bonding, magnetic and phonon properties of ScNiBi: a DFT study
No full text
Atomistic Modelling of High-Entropy Layered Anodes and Their Electrolyte Interface
No full textVan der Waals (vdW) heterostructures have attracted intense interest
worldwide as they offer several routes to design materials with novel features
and wide-ranging applications. Unfortunately, at present, vdW heterostructures
are restricted to a small number of stackable layers, due to the weak vdW
forces holding adjacent layers together. In this work, we report on
computational studies of a bulk vdW material consisting of alternating TiS2 and
TiSe2 (TSS) vertically arranged layers as a potential candidate for anode
applications. We use density functional theory (DFT) calculations and ab-initio
molecular dynamics (AIMD) simulations to explore the effect of high entropy on
several electrochemically relevant properties of the bulk heterostructure
(TSS-HS) by substituting Mo6+ and Al3+ at the transition metal site (Ti4+). We
also study the solvation shell formation at the electrode-electrolyte interface
(EEI) using AIMD to determine Li-coordination. Based on the properties computed
using DFT and AIMD we propose that high entropy TSS-HS (TSS-HE) might possess
improved electrochemical performance over standard TSS-HS. Factors that could
improve the performance of TSS-HE are 1) Less structural deformation, 2) Strong
bonding (Metal-Oxygen), 3) Better electron mobility, 4) Wider operational
voltage window, and 5) Faster Li-ion diffusion. Our observations suggest that
'high entropy' can be an effective strategy to design new anode materials for
improving electrochemical performance of Li-ion batteries
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