Complete quantum-inspired framework for computational fluid dynamics

Computational fluid dynamics is both an active research field and a key tool for industrial applications. The central challenge is to simulate turbulent flows in complex geometries, a compute-power intensive task due to the large vector dimensions required by discretized meshes. Here, we propose a full-stack solver for incompressible fluids with memory and runtime scaling polylogarithmically in the mesh size. Our framework is based on matrix-product states, a powerful compressed representation of quantum states. It is complete in that it solves for flows around immersed objects of diverse geometries, with non-trivial boundary conditions, and can retrieve the solution directly from the compressed encoding, i.e. without ever passing through the expensive dense-vector representation. These developments provide a toolbox with potential for radically more efficient simulations of real-life fluid problems

Early Healing Events around Titanium Implant Devices with Different Surface Microtopography: A Pilot Study in an In Vivo Rabbit Model

In the present pilot study, the authors morphologically investigated sandblasted, acid-etched surfaces (SLA) at very early experimental times. The tested devices were titanium plate-like implants with flattened wide lateral sides and jagged narrow sides. Because of these implant shape and placement site, the device gained a firm mechanical stability but the largest portion of the implant surface lacked direct contact with host bone and faced a wide peri-implant space rich in marrow tissue, intentionally created in order to study the interfacial interaction between metal surface and biological microenvironment. The insertion of titanium devices into the proximal tibia elicited a sequence of healing events. Newly formed bone proceeded through an early distance osteogenesis, common to both surfaces, and a delayed contact osteogenesis which seemed to follow different patterns at the two surfaces. In fact, SLA devices showed a more osteoconductive behavior retaining a less dense blood clot, which might be earlier and more easily replaced, and leading to a surface-conditioning layer which promotes osteogenic cell differentiation and appositional new bone deposition at the titanium surface. This model system is expected to provide a starting point for further investigations which clarify the early cellular and biomolecular events occurring at the metal surface

Sensitivity Analysis of the SHERPA Air Quality Model

Uncertainty and sensitivity analysis was conducted on the SHERPA model, predicting air quality improvement linked to emission reduction scenarios. Major responsible of output uncertainty (PM2.5 concentration reductions in g/m3) stems from the uncertainty in the policy options followed by the uncertainty in the emissions (kTon/year) of PPM, NOX, and NH3.JRC.I.1-Modelling, Indicators and Impact Evaluatio

High-mobility In2O3:H electrodes for four-terminal perovskite/CuInSe2 tandem solar cells

Four-terminal (4-T) tandem solar cells (e.g., perovskite/CuInSe2 (CIS)) rely on three transparent conductive oxide electrodes with high mobility and low free carrier absorption in the near-infrared (NIR) region. In this work, a reproducible In2O3:H (IO:H) film deposition process is developed by independently controlling H2 and O2 gas flows during magnetron sputtering, yielding a high mobility value up to 129 cm2 V–1 s–1 in highly crystallized IO:H films annealed at 230 °C. Optimization of H2 and O2 partial pressures further decreases the crystallization temperature to 130 °C. By using a highly crystallized IO:H film as the front electrode in NIR-transparent perovskite solar cell (PSC), a 17.3% steady-state power conversion efficiency and an 82% average transmittance between 820 and 1300 nm are achieved. In combination with an 18.1% CIS solar cell, a 24.6% perovskite/CIS tandem device in 4-T configuration is demonstrated. Optical analysis suggests that an amorphous IO:H film (without postannealing) and a partially crystallized IO:H film (postannealed at 150 °C), when used as a rear electrode in a NIR-transparent PSC and a front electrode in a CIS solar cell, respectively, can outperform the widely used indium-doped zinc oxide (IZO) electrodes, leading to a 1.38 mA/cm2 short-circuit current (Jsc) gain in the bottom CIS cell of 4-T tandems.This work was supported by funding from the Swiss Federal Office of Energy (SFOE)-BFE (project no. SI/501805-01), Swiss National Science Foundation (SNF)-Bridge (project no. 20B2-1_176552/1), and the European Research Council (ERC) under EU’s Horizon 2020 Research and Innovation Program (grant agreement no. 681312). We thank Dr. Yi Hou for the supply of the antireflection foil

Prediction of vascular invasion using a 7-point scale computed tomography grading system in adrenal tumors in dogs

Background: Previous studies evaluating the accuracy of computed tomography (CT) in detecting caudal vena cava (CVC) invasion by adrenal tumors (AT) used a binary system and did not evaluate for other vessels. Objective: Test a 7-point scale CT grading system for accuracy in predicting vascular invasion and for repeatability among radiologists. Build a decision tree based on CT criteria to predict tumor type. Methods: Retrospective observational cross-sectional case study. Abdominal CT studies were analyzed by 3 radiologists using a 7-point CT grading scale for vascular invasion and by 1 radiologist for CT features of AT. Animals: Dogs with AT that underwent adrenalectomy and had pre- and postcontrast CT. Results: Ninety-one dogs; 45 adrenocortical carcinomas (50%), 36 pheochromocytomas (40%), 9 adrenocortical adenomas (10%) and 1 unknown tumor. Carcinoma and pheochromocytoma differed in pre- and postcontrast attenuation, contralateral adrenal size, tumor thrombus short- and long-axis, and tumor and thrombus mineralization. A decision tree was built based on these differences. Adenoma and malignant tumors differed in contour irregularity. Probability of vascular invasion was dependent on CT grading scale, and a large equivocal zone existed between 3 and 6 scores, lowering CT accuracy to detect vascular invasion. Radiologists' agreement for detecting abnormalities (evaluated by chance-corrected weighted kappa statistics) was excellent for CVC and good to moderate for other vessels. The quality of postcontrast CT study had a negative impact on radiologists' performance and agreement. Conclusions and Clinical Importance: Features of CT may help radiologists predict AT type and provide probabilistic information on vascular invasion

Surgical findings and outcomes after unilateral adrenalectomy for primary hyperaldosteronism in cats: a multi-institutional retrospective study

Case series summary: Twenty-nine cats from different institutions with confirmed or highly suspected primary hyperaldosteronism treated by unilateral adrenalectomy were retrospectively included in this study. The most frequent clinical signs were lethargy (n = 20; 69%) and neck ventroflexion (n = 17; 59%). Hypokalaemia was present in all cats, creatinine kinase was elevated in 15 and hyperaldosteronism was documented in 24. Hypertension was frequently encountered (n = 24; 89%). Preoperative treatment included potassium supplementation (n = 19; 66%), spironolactone (n = 16; 55%) and amlodipine (n = 11; 38%). There were 13 adrenal masses on the right side, 15 on the left and, in one cat, no side was reported. The median adrenal mass size was 2 × 1.5 cm (range 1-4.6 × 0.4-3.8); vascular invasion was present in five cats, involving the caudal vena cava in four cats and the renal vein in one. Median duration of surgery was 57 mins. One major intraoperative complication (3%) was reported and consisted of haemorrhage during the removal of a neoplastic thrombus from the caudal vena cava. In 4/29 cats (14%), minor postoperative complications occurred and were treated medically. One fatal complication (3%) was observed, likely due to disseminated intravascular coagulation. The median duration of hospitalisation was 4 days; 97% of cats survived to discharge. The potassium level normalised in 24 cats within 3 months of surgery; hypertension resolved in 21/23 cats. Follow-up was available for 25 cats with a median survival of 1082 days. Death in the long-term follow-up was mainly related to worsening of comorbidities. Relevance and novel information: Adrenalectomy appears to be a safe and effective treatment with a high rate of survival and a low rate of major complications. Long-term medical treatment was not required

Flexible perovskite solar cells and mini-modules for all-thin-film tandem photovoltaics

Organic-inorganic perovskite photovoltaic (PV) technology has achieved a record efficiency approaching 24 % in less than 10 years since its first reported application in PV devices. The outstanding PV performances, high absorption coefficient, tunable band gap and low Urbach energy of this organic-inorganic material make perovskite solar cells (PSCs) ideal candidates as top cells in tandem applications. The development of tandem devices enables to improve the power conversion efficiency by reducing thermalization losses and by maximizing the absorption over the entire solar spectrum. All-thin-film perovskite/Cu(In,Ga)Se2 (CIGS) tandem solar cells in four-terminal configuration with efficiencies approaching 25 % have been demonstrated. In addition, PSCs can be efficiently prepared by low-temperature processes on flexible substrates, with reported efficiencies as high as 19 %. As well, CIGS solar cells can be developed on flexible substrates with high efficiencies (> 20 %). The development of flexible PV devices opens the way to high throughput roll-to-roll manufacturing with low embodied energy, and to new applications such as building- or transport-integrated products, as well as internet-of-thing based devices. This thesis focuses on the development of efficient near-infrared (NIR) transparent PSCs grown via low-temperature processing onto a flexible foil, which is commonly used to encapsulate flexible CIGS modules. These developments aim to lay the foundations to future manufacturing of flexible perovskite/CIGS tandem devices by direct integration of the two technologies via high-throughput roll-to-roll processing, considering that the employed flexible foil would avoid any additional costs for the top cell substrate. In addition, the upscaling potential of the developed flexible PSC structure is proved onto larger areas (from 0.15 cm2 to > 10 cm2) and highly accurate scribing methods are employed to realize monolithically-integrated flexible perovskite mini-modules. At first, a low-temperature PSC structure is developed based on an alternative highly NIR-transparent transparent conducting oxide (TCO), Al-doped ZnO (AZO). Thermally evaporated C60 is developed as low-temperature deposited electron transport layer (ETL) to efficiently extract electrons and mitigate hysteresis phenomenon in the flexible PSCs. Efficiencies above 13 % and 11 % are demonstrated on 0.15 and > 1 cm2 active areas, respectively. For tandem application, the gold rear electrode is substituted with a transparent one (appropriate combination of MoOx buffer layer and highly NIR-transparent In2O3:H TCO) to allow efficient transmission of low energy photons, resulting in a 12.2 % NIR-transparent flexible PSC with an average transmittance of 78 %, between 800-1000 nm. As a first proof-of-concept, a flexible perovskite/CIGS tandem cell with an efficiency > 18 % (higher than both single-junction devices) is demonstrated in four-terminal configuration. Through ultraviolet photoelectron spectroscopy (UPS) measurements, the interface between AZO and C60 is identified as a bottleneck for the performances of the developed flexible PSCs, due to unfavorable upward band bending at the TCO/ETL interface that hinders efficient charge extraction. The power conversion efficiency is improved by appropriate interlayer application. Solution processed polyethylenimine ethoxylated (PEIE) and vacuum deposited LiF interfacial modifications enables an absolute efficiency improvement of 2 %. A modulation of the electrostatic potential is verified once interlayers are applied, resulting in a favorable downward band bending at the AZO/C60 interface that results in enhanced electrons extraction. In addition, focusing on the use of vacuum deposited LiF interlayer, better suited for large area processing, a flexible perovskite mini-module with an efficiency of 10.5 % onto an aperture area > 10 cm2 is developed. Laser scribing method is successfully employed to realize monolithically interconnected flexible mini-module with low dead area losses. This precise and accurate approach yields a geometric fill factor (GFF) of 94 %. However, the low-temperature deposited PSC structure developed displays limited Jsc values with respect to state-of-the-art devices. A method is then presented to tackle this issue via a modified vacuum-solution (multi-stage) deposition approach, tailoring PbI2 growth to facilitate organic cations intercalation and to effectively increase perovskite thickness. Through this multi-stage deposition, an improvement in efficiencies for flexible PSCs is shown (from 14.2 % to 15.8 %) thanks to enhanced absorption in the perovskite layer. In addition, in these devices an amorphous TCO, InZnO (IZO), is used, further proving superior bending stability with respect to the initially developed crystalline AZO and to other commonly used TCOs for flexible PSCs. Flexible devices retained 90 % and 80 % of the initial efficiency after 1000 bending cycles at 6 and 4 mm bending radii, respectively. Via the multi-stage process, a flexible NIR-transparent PSC with an efficiency of 14.0 % is presented. By combining the flexible perovskite top cell with a flexible CIGS bottom cell, a flexible perovskite/CIGS tandem, with an efficiency of 19.6 % measured in four-terminal configuration is eventually demonstrated. In order to identify the main steps to improve the efficiency of the developed flexible PSCs, the final part of the thesis focuses on systematic loss analyses. Through transfer-matrix method (TMM)-based simulations, optical losses can be expressed in terms of the corresponding Jsc losses: The front IZO and C60 layers represent a source of parasitic absorption (losses amount to 1.2 mA cm−2) and strong reflection losses are observed between 450- 500 nm. The optical loss analyses are then complemented with a systematic analysis of nonradiative recombination losses. By absolute photoluminescence (PL) measurements, the C60/CH3NH3PbI3 (MAPI) interface results to be a significant source of Voc losses (the QFLS decreases from 1.23 eV for the bare MAPI to 1.10 eV for MAPI grown on C60). To reduce these losses different vacuum deposited interlayers (BCP, B4PyMPM, 3TPYMB and LiF) are screened. An improvement in QFLS of 30-40 meV is observed with respect to C60/MAPI heterojunction by employing B4PyMPM, 3TPYMB and LiF. Their further implementation in flexible PSCs support the conclusions from absolute PL, observing a comparable improvement in Voc values when these interlayers are applied, confirming their passivating role against non-radiative recombination. Further investigations on MAPI/hole transport layer (HTL) interface point out the detrimental role of dopants in Spiro-OMeTAD film (widely employed HTL in the community) as recombination centers upon oxidation and light exposure

Be international or be innovative? be both? The role of the entrepreneurial profile

Be international? Be innovative? Be international and innovative? Following the logic of the upper echelon (UE) perspective, this paper studies the impact of the entrepreneur(s) demography, background, and experience on their strategic choices, i.e., innovation, internationalization, or a combination of the two strategies. We employ cluster analysis on a sample of 88 Italian Small- and Medium-sized Enterprises (SMEs) operating in different industries to classify the firms along their entrepreneur(s)\u2019 characteristics. Three significantly different clusters emerge, i.e., the typical Italian family firms, a group of businesses led by solitary self-made men, and the team-founded firms. The three groups are related to differences in internationalization behavior and innovation practice. Family-led firms are mainly domestic and concentrated on product innovation, while team-founded firms combine intensive internationalization with innovative marketing and management practices. A third cluster describes the solitary founder with serial business experience, whose businesses foster product and process innovation combined with moderate levels and scope of internationalization. Furthermore, our findings reveal that internationalization tends to be related to the type of innovation, much more than to R&D intensity or other measures of novelty (i.e., radical or incremental)

BE INTERNATIONAL OR BE INNOVATIVE? THE IMPACT OF ENTREPRENEURIAL PROFILES IN DRIVING THE STRATEGY OF SMES

Be international or be innovative? Or be both? This is a common dilemma for small and medium enterprises (SMEs) which often perceive their lack of resources as a barrier to implementing both development paths at the same time. This paper argues that characteristics of the entrepreneur/the management team play a crucial role in that they drive the firm towards one or a combination of these two alternative growth strategies,. providing entrepreneurs with a much better understanding of the main strategic options and their relationship with the performance of the firm. We provide a literature review on extant research which deals with the characteristics of entrepreneurs as related to innovation and internationalisation and the associated performance consequences. The empirical investigation is based on a sample of Italian SMEs. operating in Lombardy in different industries – one of the strongest economic areas – which was drawn from official statistic. Cluster analysis is used to group the SMEs along their entrepreneurial profiles, internationalization degrees and innovation orientation. Three significantly different groups emerge, i.e. the typical Italian family firm, a group of businesses which represents the solitary self-made man, and the team-founded firms. These three clusters show significant differences in internationalisation and innovation behaviour. Interestingly, the three groups’ degree of internationalization seems to be more a question of type (product, process, marketing/organizational practice) than of level of innovation Team-founded firms, which innovate marketing/organizational practices, are the most intensive internationalisers, whereas family firms concentrate predominantly on product innovation and the domestic market. The study contributes to the debate about the relation between internationalization and innovation from an entrepreneurship point of view ad offers insights s for SMEs regarding the choice of growth strategies