216 research outputs found
Measuring greenwashing: A systematic methodological literature review
Greenwashing (GW) is a complex, dynamic, interdisciplinary, multidimensional, and multifaceted phenomenon. There are more theoretical than empirical studies on GW because of several difficulties in collecting accurate data and obtaining objective GW measures. After disentangling the multifaceted GW phenomenon by describing its main dimensions, this study provides a systematic methodological literature review on empirical research papers published from 1990 to 2022 in journals of Business, Management, and Accounting to understand how empirical researchers are operationalizing GW and how our methodological choices affect our understanding of this phenomenon. Our results show that the actual GW operationalization is challenging and that scholars are highly uncertain about how such operationalization should
be designed and implemented to provide an effective GW measurement instrument.
Further, a growing number of studies investigate hypothetical GW cases adopting perception-based measures, while limited research explores real GW cases
Sixty years of the Voting Rights Act: progress and pitfalls
We review the literature on the effects of the 1965 Voting Rights Act (VRA), which removed formal restrictions to Black political participation. After a brief description of racial discrimination suffered by Black Americans since Reconstruction, we introduce the goals that the VRA was meant to achieve. Next, we discuss the local level impact of the law on political participation and representation, on public goods provision and policing practices, and on labor market outcomes. We then turn to whites’ reactions, from political realignment to electoral counter-mobilization to changes in voting rules and arrests patterns. We conclude by discussing how the evidence reviewed in this article can inform policy-making and the design of legislation aimed at reducing racial discrimination and inequality
Black empowerment and white mobilization: the effects of the Voting Rights Act
The 1965 Voting Rights Act (VRA) paved the road to Black empowerment. How did southern whites respond? Leveraging newly digitized data on county-level voter registration rates by race between 1956 and 1980, and exploiting pre-determined variation in exposure to the federal intervention, we document that the VRA increases both Black and white political participation. Consistent with the VRA triggering countermobilization, the surge in white registrations is concentrated where Black political empowerment is more tangible and salient due to the election of African Americans in county commissions. Additional analysis suggests that the VRA has long-lasting negative effects on whites’ racial attitudes
Aerodynamic design methodology for wind tunnel tests of wind turbine rotors
This paper illustrates the methodology and the experimental verification of the design of a 1/75 aero-elastic scaled rotor of the DTU 10 MW reference wind turbine for wind tunnel tests. The aerodynamic design was focused on the minimization of the difference, in terms of thrust coefficient, with respect to the full scale reference. From the Selig low-Reynolds airfoils database, the SD7032 one was chosen for this purpose and a corresponding constant section wing was tested at DTU red wind tunnel, providing force and distributed pressure coefficients for the design, in the Reynolds range 30−250×103 and for different angles of attack. The aero-elastic design algorithm was set to define the optimal spanwise thickness over chord ratio (t/c), the chord length and the twist, in order to match at least the first flapwise scaled natural frequency. An aluminium mould for the carbon fibre autoclave process was CNC manufactured based on B-Splines CAD definition of the external geometry given as an output of the design procedure. Wind tunnel tests at were carried out Politecnico di Milano on the whole 1/75 wind turbine scale model, confirming the successful aerodynamic design and manufacturing approaches. The experimental modal analysis carried out to verify the structural consistency of the scaled blade is also reported
Wind tunnel validation of AeroDyn within LIFES50+ project: Imposed Surge and Pitch tests
This paper presents the first set of results of the steady and unsteady wind tunnel tests, performed at Politecnico di Milano wind tunnel, on a 1/75 rigid scale model of the DTU 10 MW wind turbine, within the LIFES50+ project. The aim of these tests is the validation of the open source code AeroDyn developed at NREL. Numerical and experimental steady results are compared in terms of thrust and torque coefficients, showing good agreement, as well as for unsteady measurements gathered with a 2 degree-of-freedom test rig, capable of imposing the displacements at the base of the model, and providing the surge and pitch motion of the floating offshore wind turbine (FOWT) scale model. The measurements of the unsteady test configuration are compared with AeroDyn/Dynin module results, implementing the generalized dynamic wake (GDW) model. Numerical and experimental comparison showed similar behaviours in terms of non linear hysteresis, however some discrepancies are herein reported and need further data analysis and interpretations about the aerodynamic integral quantities, with a special attention to the physics of the unsteady phenomenon
Subcutaneous Tissue Expander Placement with Synthetic Titanium-Coated Mesh in Breast Reconstruction: Long-term Results
A subcutaneous, prepectoral, muscle-sparing approach has been recently described for implant-based breast reconstruction. This is a preliminary series of 2-stage breast reconstructions by means of tissue expander placed subcutaneously with the support of a titanium-coated polypropylene mesh. A pilot series of cases was started in 2012. Inclusion criteria were informed consent, age less than 80 years, normal body mass index (range, 18.5–24.9), no T4 and metastatic cancers, no comorbidities, and nonsmoking patients. Expander losses, infections, seromas, skin/nipple necrosis, wound dehiscence, and reinterventions were registered in follow-up visits. Furthermore, patients were followed up in second-stage procedures and for at least 1 year from implant positioning to collect any surgical complication, reinterventions, cosmetic outcome, and oncological data. Between June 2012 and March 2014, 25 cases were enrolled in the study. Expander/implant loss rate was 0%. Skin/nipple necrosis rate was 4%. Infections rate was 12% after first-stage and 4% after second-stage procedure. Seromas rate was 0%. Five (20%) fat graft procedures were performed over the expander before second-stage reconstruction, and no reinterventions were required after second stage. Patients mean score was 99 for cosmetic outcome satisfaction, in a 0–100 scale. Subcutaneous 2-stage reconstruction with synthetic mesh proved safe and feasible. Patients satisfaction is very good after 14 months median follow-up form definitive implant placement. Although the present study involved only a small number of cases, a tissue-expander subcutaneous reconstruction seems to have promising results. Whenever pectoralis major muscle can be spared, a conservative reconstruction might be an option
Unexpected different chemoselectivity in the aerobic oxidation of methylated planar catechin and bent epicatechin derivatives catalysed by the Trametes villosa laccase/1-hydroxybenzotriazole system
Unreported methylated catechin and epicatechin derivatives 5 and 6 were synthesized by an oxa-Pictet-
Spengler reaction. Catechin 5 shows the B and C rings coplanar because of the formation of a trans
junction between the C ring and the newly generated six-term cycle D, in turn condensed to ring B. In
contrast, epicatechin 6 presents a bent geometry due to the establishment of a cis junction between the
C ring and the newly formed cycle D. The oxidation of compounds 5 and 6 in the presence of the
Trametes villosa laccase/1-hydroxybenzotriazole (HBT) system was investigated under aerobic conditions
in both a biphasic system and a reverse micelle. The unexpected different chemoselective oxidation at
the benzylic position of catechin and epicatechin derivatives 5 and 6 has been rationalized using a
molecular modelling approach. These results demonstrate that the Trametes villosa laccase/HBT system
represents a useful tool to functionalize the C-2 or C-4 position of phenolic compounds depending on
the structural features
Trapping at the Solid−Gas Interface: Selective Adsorption of Naphthalene by Montmorillonite Intercalated with a Fe(III)− Phenanthroline Complex
In this study, stable hybrid materials (Mt−Fe(III)Phen),
made by the μ-oxo Fe(III)−phenanthroline complex [(OH2)3(Phen)-
FeOFe(Phen)(OH2)3]4+ (Fe(III)Phen) intercalated in different amounts
into montmorillonite (Mt), were used as a trap for immobilizing gaseous
benzene and naphthalene and their mono chloro-derivatives at 25 and 50
°C. The entrapping process was studied through elemental analysis, magic
angle spinning NMR spectroscopy, thermal analysis, and evolved gas mass
spectrometry. Naphthalene and 1-chloronaphthalene were found to be
immobilized in large amount at both temperatures. Molecular modeling
allowed designing of the structure of the interlayer in the presence of the
immobilized aromatic molecules. Adsorption is affected by the amount of
the Fe complex hosted in the interlayer of the entrapping hybrid materials.
On the contrary, under the same conditions, benzene and chlorobenzene
were not adsorbed. Thermal desorption of naphthalenes was obtained
under mild conditions, and immobilization was found to be reversible at least for 20 adsorption/desorption cyclesThe authors are thankful to the University of Modena and
Reggio Emilia for FAR 2016 funding program (PAsTIME
Project, grant number: FAR2016DIPBORSARI), for the
Visiting Professor program, and for the facilities provided by
the Centro Interdipartimentale Grandi Strumenti, to MIUR for
funding program FFABR 2017, to the Computational Centre
of University of Granada and CINECA of Bologna for the
high-performance computing service, and to the Andalusian
project RMN1897 and the Spanish projects FIS2013-48444-
C2-2-P and FIS2016-77692-C2-2-P for financial support
Excitation-Energy Transfer Paths from Tryptophans to Coordinated Copper Ions in Engineered Azurins: a Source of Observables for Monitoring Protein Structural Changes
The intrinsic fluorescence of recombinant proteins offers a powerful tool to detect and characterize structural changes induced by chemical or biological stimuli. We show that metal-ion binding to a hexahistidine tail can significantly broaden the range of such structurally sensitive fluorescence observables. Bipositive metal-ions as Cu2+, Ni2+ and Zn2+ bind 6xHis-tag azurin and its 6xHis-tagged R129W and W48A-R129W mutants with good efficiency and, thereby, quench their intrinsic fluorescence. Due to a much more favourable spectral overlap, the 6xHis-tag/Cu2+ complex(es) are the most efficient quenchers of both W48 and W129 emissions. Based on simple F\uf6rster-type dependence of energy-transfer efficiency on donor/acceptor distance, we can trace several excitation-energy transfer paths across the protein structure. Unexpected lifetime components in the azurin 6xHis-tag/Cu2+ complex emission decays reveal underneath complexity in the conformational landscape of these systems. The new tryptophan emission quenching paths provide additional signals for detecting and identifying protein structural changes
TiLoop® Bra mesh used for immediate breast reconstruction: comparison of retropectoral and subcutaneous implant placement in a prospective single-institution series
primo studio sulla ricostruzione immediata con rete T loop e protesi definitiva in donne mastectomizzate.BACKGROUND:
Immediate implant reconstruction after a conservative mastectomy is an attractive option made easier by prosthetic devices. Titanized polypropylene meshes are used as a hammock to cover the lower lateral implant pole. We conducted a prospective nonrandomized single-institution study of reconstructions using titanium-coated meshes either in a standard muscular mesh pocket or in a complete subcutaneous approach. The complete subcutaneous approach means to wrap an implant with titanized mesh in order to position the implant subcutaneously and spare muscles.
METHODS:
Between November 2011 and January 2014, we performed immediate implant breast reconstructions after conservative mastectomies using TiLoop® Bra, either with the standard retropectoral or with a prepectoral approach. Selection criteria included only women with normal Body Mass Index (BMI), no large and very ptotic breasts, no history of smoking, no diabetes, and no previous radiotherapy. We analyzed short-term outcomes of such procedures and compared the outcomes to evaluate implant losses and surgical complications.
RESULTS:
A total of 73 mastectomies were performed. Group 1 comprised 29 women, 5 bilateral procedures, 34 reconstructions, using the standard muscular mesh pocket. Group 2 comprised 34 women, 5 bilateral procedures, 39 reconstructions with the prepectoral subcutaneous technique. Baseline and oncologic characteristics were homogeneous between the two groups. After a median follow-up period of 13 and 12 months, respectively, no implant losses were recorded in group 1, and one implant loss was recorded in group 2. We registered three surgical complications in group 1 and two surgical complications in group 2.
CONCLUSIONS:
Titanium-coated polypropylene meshes, as a tool for immediate definitive implant breast reconstruction, resulted as safe and effective in a short-term analysis, both for a retropectoral and a totally subcutaneous implant placement. Long-term results are forthcoming. A strict selection is mandatory to achieve optimal results. Level of Evidence: Level II, therapeutic stud
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