Multi-Objective Density Diagrams Developed With Machine Learning Models to Optimize Sustainability and Cost-Efficiency of UHPC Mix Design

The emergence of ultra-high-performance concrete (UHPC) as an attractive solution for precast and prestressed applications has coincided with global efforts towards sustainable construction. The increasing need for tools capable of intuitively demonstrating the effect of concrete mixture composition on mechanical performance, cost and eco-efficiency concurrently has motivated this work in an effort to promote design of more sustainable solutions to help meet environmental goals. Such tools are needed to effectively evaluate the environmental impact of UHPC given the outstanding mechanical properties of the material coupled with high volumetric embodied CO2. Meanwhile, artificial intelligence (AI) techniques have emerged as a great opportunity for game-changing tools capable of effectively modeling the synergistic relationships between mix proportions and material performance. This work couples machine learning models with orthogonal arrays to generate machine-learning-based tools to evaluate the tradeoffs between emissions, cost and mechanical performance concurrently. Random forest and k-nearest neighbors’ models are ensembled to predict the compressive strength of UHPC mixtures and generate Performance Density Diagrams (PDDs). These predicted strengths are then coupled with volumetric environmental factors and unit costs to generate eco- and cost-efficiency density diagrams. The makeup of these tools facilitates the evaluation of rather complicated trends associated with mix proportions and multi-objective outcomes, allowing AI-based tools to be of easy use by industry personnel on a daily basis, while serving as decision-making aids during mix design stages and provide proof of mixture optimization that could be introduced in Environmental Product Declarations. The PDD developed herein enabled the design of a mix with compressive strength of 155 MPa, while keeping the aggregate-to-cementitious ratio above unit. Other mixtures were developed from these models and compared to several different concretes from the literature. Results show that high paste content, high strength (and ultra-high strength) concrete technologies are not necessarily detrimental to cost or eco efficiencies. For the different indices evaluated, optimum solutions were mostly obtained with these types of concrete, which means that industry trends toward requiring minimization of embodied CO2 in concrete on a per volume basis are misguided and do not minimize the embodied CO2 in concrete structures

Peripheral Nerve Repair with Cultured Schwann Cells: Getting Closer to the Clinics

Peripheral nerve injuries are a frequent and disabling condition, which affects 13 to 23 per 100.000 persons each year. Severe cases, with structural disruption of the nerve, are associated with poor functional recovery. The experimental treatment using nerve grafts to replace damaged or shortened axons is limited by technical difficulties, invasiveness, and mediocre results. Other therapeutic choices include the adjunctive application of cultured Schwann cells and nerve conduits to guide axonal growth. The bone marrow is a rich source of mesenchymal cells, which can be differentiated in vitro into Schwann cells and subsequently engrafted into the damaged nerve. Alternatively, undifferentiated bone marrow mesenchymal cells can be associated with nerve conduits and afterward transplanted. Experimental studies provide evidence of functional, histological, and electromyographical improvement following transplantation of bone-marrow-derived cells in animal models of peripheral nerve injury. This paper focuses on this new therapeutic approach highlighting its direct translational and clinical utility in promoting regeneration of not only acute but perhaps also chronic cases of peripheral nerve damage

Perpendicular momentum injection by lower hybrid wave in a tokamak

The injection of lower hybrid waves for current drive into a tokamak affects the profile of intrinsic rotation. In this article, the momentum deposition by the lower hybrid wave on the electrons is studied. Due to the increase in the poloidal momentum of the wave as it propagates into the tokamak, the parallel momentum of the wave increases considerably. The change of the perpendicular momentum of the wave is such that the toroidal angular momentum of the wave is conserved. If the perpendicular momentum transfer via electron Landau damping is ignored, the transfer of the toroidal angular momentum to the plasma will be larger than the injected toroidal angular momentum. A proper quasilinear treatment proves that both perpendicular and parallel momentum are transferred to the electrons. The toroidal angular momentum of the electrons is then transferred to the ions via different mechanisms for the parallel and perpendicular momentum. The perpendicular momentum is transferred to ions through an outward radial electron pinch, while the parallel momentum is transferred through collisions.Comment: 22 pages, 4 figure

Verification of clinical guidelines encoded into knowledge-based DSSs

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Surgical treatment in patient with non-small-cell lung cancer with fissure involvement: Anatomical versus nonanatomical resection

OBJECTIVE: Despite the intense debate concerning the prognostic impact of fissure involvement (FI) in patients with non-small-cell lung cancer, no specific surgical strategies have been yet recommended when this condition occurs. In this setting, we report our monocentric 10-years experience to investigate this issue. METHODS: From January 2000 to January 2010, the clinical data of 40 non-small-cell lung cancer patients with FI undergoing curative resection were retrospectively reviewed. The sample was stratified according to the type of resection: group A (28 patients): anatomical resection (bilobectomy [21 patients], pneumonectomy [7 patients]); group B (12 patients): nonanatomical resection (lobectomy plus wedge resection [LWR]). The end-points were (1) impact of different surgical approach on the pulmonary function (measured before surgery and 1 month after discharge); (2) disease-specific survival; and (3) tumor recurrence.The t test, χ, and log-rank tests, Kaplan-Meier method, and Cox and logistic regression analyses were used for the statistical analysis. RESULTS: No differences between the two groups were found when comparing the clinical characteristics, histology, pN or pT status, p-stage, residual (R1) disease, tumor grading, or tumor size. Similarly, the baseline preoperative function (tested as forced expiratory volume in 1 second-%-predicted, FEV1%) was likewise comparable (92.5% ± 21.0% in group A versus 85.2% ± 20.0% in group B; p = not significant). The decline of FEV1% after surgery was slightly higher in group A (-24.9% ± 13.5%) when compared with that in group B (-19.5% ± 13.3%), but this difference was not statistically significant (p = ns). Nevertheless, the 5-year disease-specific survival was 56% for group A and 47% for group B (p = ns). The recurrence rate did not differ between the patients undergoing a LWR (3 of 12 patients) and those undergoing a bilobectomy or pneumonectomy (9 of 28 patients) (p = ns). The presence of FI extended for more than 3 cm was found to be the most significant prognostic factor when analyzing survival (p = 0.002) and recurrence rate (p< 0.001). CONCLUSIONS: Our results suggest that nonanatomical resection (LWR) could be considered as a feasible surgical option (especially in "frail" patients with an extent of FI less than 3 cm) in the light of the similar oncological and functional outcome compared with anatomical resection. Further studies based on larger series are needed to confirm these preliminary data and also to investigate the impact on the postoperative quality of life

InGaN green light emitting diodes with deposited nanoparticles

We grew an InGaN/GaN-based light-emitting diode (LED) wafer by metal-organic chemical vapor deposition (MOCVD), fabricated devices by optical lithography, and successfully deposited ellipsoidal Ag nano-particles by way of e-beam lithography on top. The diodes exhibited good device performance, in which we expected an enhancement of the radiated intensity by the simulations and emission measurements. The obtained results showed the feasibility of plasmon-assisted LED emission enhancement. © 2007

Management of syncope: clinical and economic impact of a Syncope Unit

Aims Aim of this observational study is to evaluate the clinical performance of a Syncope Unit, in order to assess whether the implemented organization really improves syncope management. Methods and results The study enrolled patients with unexplained syncope who were consecutively referred to our Syncope Unit, either as outpatients or during hospitalization, in a 2-month period. The design of this observational study consists in three phases: a retrospective analysis of their clinical. management in the 9 months prior to the first attendance at the Syncope Unit (phase one), their subsequent clinical management in the Syncope Unit (phase two) and a 9-month follow-up (phase three). The retrospective analysis of phase one showed that 25% of patients had already been hospitalized without diagnosis. After Syncope Unit evaluation, diagnosis was obtained in 82% of patients, with 15% of patients indicated to pacing. In the follow-up, 23% of patients experienced a syncopal recurrence. Our analysis indicated an 85% reduction of hospital costs in the follow-up period. Conclusion The clinical and economic analysis of the three phases of our study demonstrates that a Syncope Unit allows an improved management of patients with syncope