Optimization methods and silicon solar cell numerical models

The goal of this project is the development of an optimization algorithm for use with a solar cell model. It is possible to simultaneously vary design variables such as impurity concentrations, front junction depth, back junctions depth, and cell thickness to maximize the predicted cell efficiency. An optimization algorithm has been developed and interfaced with the Solar Cell Analysis Program in 1 Dimension (SCAPID). SCAPID uses finite difference methods to solve the differential equations which, along with several relations from the physics of semiconductors, describe mathematically the operation of a solar cell. A major obstacle is that the numerical methods used in SCAPID require a significant amount of computer time, and during an optimization the model is called iteratively until the design variables converge to the value associated with the maximum efficiency. This problem has been alleviated by designing an optimization code specifically for use with numerically intensive simulations, to reduce the number of times the efficiency has to be calculated to achieve convergence to the optimal solution. Adapting SCAPID so that it could be called iteratively by the optimization code provided another means of reducing the cpu time required to complete an optimization. Instead of calculating the entire I-V curve, as is usually done in SCAPID, only the efficiency is calculated (maximum power voltage and current) and the solution from previous calculations is used to initiate the next solution

Esecuzione e interpretazione di prove sperimentali su pareti realizzate con tecnologia "ISOSPAN".

In recent years, the resistance of reinforced concrete bearing panels structures has been the object of several research works, to assess the effective behavior of this kind of materials in static and seismic situations. Despite the wide use of this kind of concrete walls in Northern Europe the national regulations are not very detailed and specific. In fact, regarding the structural elements without reinforcement or partially reinforced employed in the industrial buildings, there are no common methods or approved procedures to calculate the strength of this kind walls, both Italian and European (Eurocodes) regulations. In order to partially fill this gap the Italian Ministry of Public Works issued some Guidelines in the July 2011 concerning the construction technique in object, where a series of laboratory tests should be carried on to investigate the mechanical properties (Young and shear moduli) and the panels behavior under different loads and with different geometries. This paper presents a summary of the experimental results of some tests conducted following the above Guidelines and the comparison of these with the analytical results of a proposed procedure

Optimization methods and silicon solar cell numerical models

An optimization algorithm for use with numerical silicon solar cell models was developed. By coupling an optimization algorithm with a solar cell model, it is possible to simultaneously vary design variables such as impurity concentrations, front junction depth, back junction depth, and cell thickness to maximize the predicted cell efficiency. An optimization algorithm was developed and interfaced with the Solar Cell Analysis Program in 1 Dimension (SCAP1D). SCAP1D uses finite difference methods to solve the differential equations which, along with several relations from the physics of semiconductors, describe mathematically the performance of a solar cell. A major obstacle is that the numerical methods used in SCAP1D require a significant amount of computer time, and during an optimization the model is called iteratively until the design variables converge to the values associated with the maximum efficiency. This problem was alleviated by designing an optimization code specifically for use with numerically intensive simulations, to reduce the number of times the efficiency has to be calculated to achieve convergence to the optimal solution

Static and seismic performances of R.C. shear walls cast into wood chip and cement formworks - Experimental tests, theoretical interpretation and numerical validations

The purpose of this thesis is to study the behavior of the particular building system that makes use of load-bearing walls of reinforced concrete cast into mineralized wood. This construction system has been studied under the action of pseudo-static forces (experimentally and numerically) and under dynamic forces (only numerically). The activities carried out, in general, employed experimental equipment for the realization of tests on materials and on specimens that can be both portions and real scale walls. Additionally, a commercial software has been used for the numerical modeling of the elements composing the construction system in object. In particular, in the first chapters of the thesis, a complete analytical treatment based on experimental results obtained in the years before the Ph.D beginning and during the Ph.D is provided. The original aspects, from the experimental point of view, were the two experimental campaigns concerning portions of panel subjected to direct shear and real scale walls subjected to cyclic horizontal forces in a pseudo-static fashion. In addition, the experimental campaign was completed with the tests on wall-to-wall and wall-to-floor connections required by LL. GG. Min. of Public Works (2011) and aimed at the study of load-bearing walls cast within formwork blocks. The direct shear tests have shown an incongruity of the experimental results with the first analytical treatment developed in the years before 2012 and therefore it was necessary to revise it with new theoretical considerations. A new and original analytical treatment based on strut-and-tie mechanisms was developed. In the last chapters, the construction system has been treated numerically. In the numerical modeling of the structural system the analytical treatment exposed in the first chapters was employed using elements with lumped and distributed plasticity able to simulate the main failure mechanisms documented in the experimental tests. This modeling was first validated on the results of tests on full-scale walls and then used to simulate the behavior of multi-story buildings, regular and irregular, with bi-dimensional and spatial models. These buildings have been subjected to static and dynamic forces typical of seismic action. The numerical results of the simulations coupled with the capacity curves enabled the estimate of the seismic response of the building system and, finally, the behavior factor which best synthesizes it. The estimate of this parameter is of fundamental importance in seismic design, it is one of the main research results. It is worth to notice that the Italian Guidelines prescriptions regarding the behavior factor are more conservative with respect to the results of this researc

Challenging the drug-likeness dogma for new drug discovery in Tuberculosis

The emergence of multi- and extensively drug resistant tuberculosis worldwide poses a great threat to human health and highlight the need to discover and develop new, effective and inexpensive antituberculosis agents. High-throughput screening assays against well-validated drug targets and structure based drug design have been employed to discover new lead compounds. However, the great majority fail to demonstrate any antimycobacterial activity when tested against Mycobacterium tuberculosis in whole-cell screening assays. This is mainly due to some of the intrinsic properties of the bacilli, such as the extremely low permeability of its cell wall, slow growth, drug resistance, drug tolerance, and persistence. In this sense, understanding the pathways involved in M. tuberculosis drug tolerance, persistence, and pathogenesis, may reveal new approaches for drug development. Moreover, the need for compounds presenting a novel mode of action is of utmost importance due to the emergence of resistance not only to the currently used antituberculosis agents, but also to those in the pipeline. Cheminformatics studies have shown that drugs endowed with antituberculosis activity have the peculiarity of being more lipophilic than many other antibacterials, likely because this leads to improved cell penetration through the extremely waxy mycobacterial cell wall. Moreover, the interaction of the lipophilic moiety with the membrane alters its stability and functional integrity due to the disruption of the proton motive force, resulting in cell death. When a ligand-based medicinal chemistry campaign is ongoing, it is always difficult to predict whether a chemical modification or a functional group would be suitable for improving the activity. Nevertheless, in the "instruction manual" of medicinal chemists, certain functional groups or certain physicochemical characteristics (i.e., high lipophilicity) are considered red flags to look out for in order to safeguard drug-likeness and avoid attritions in the drug discovery process. In this review, we describe how antituberculosis compounds challenge established rules such as the Lipinski's "rule of five" and how medicinal chemistry for antituberculosis compounds must be thought beyond such dogmatic schemes.publishersversionpublishe

Wiring the oncogenic circuitry: Pin1 unleashes mutant p53

4nonenoneNapoli M; Girardini JE; Piazza S; Del Sal GNapoli, Marco; Girardini, Je; Piazza, S; DEL SAL, Giannin

Cereblon versus VHL:Hijacking E3 ligases against each other using PROTACs

<div> <div> <div> <p>The von Hippel-Lindau (VHL) and cereblon (CRBN) proteins are substrate recognition subunits of two ubiquitously expressed and biologically important Cullin RING E3 ubiquitin ligase complexes. VHL and CRBN are also the two most popular E3 ligases being recruited by bifunctional Proteolysis-targeting chimeras (PROTACs) to induce ubiquitination and subsequent proteasomal degradation of a target protein. Using homo-PROTACs, VHL and CRBN have been independently dimerized to induce their own degradation. Here we report the design, synthesis and cellular activity of VHL-CRBN hetero-dimerizing PROTACs featuring diverse conjugation patterns. We found that the most active compound 14a induced potent, rapid and profound preferential degradation of CRBN over VHL in cancer cell lines. At lower concentrations, weaker degradation of VHL was instead observed. This work demonstrates proof of concept of designing PROTACs to hijack different E3 ligases against each other, and highlights a powerful and generalizable proximity-induced strategy to achieve E3 ligase knockdown. </p> </div> </div> </div

PREVALÊNCIA DE AGENTES CAUSADORES DE MASTITE EM BOVINOS CRIADOS EM SISTEMA DE ALOJAMENTO FREE STALL NA REGIÃO OESTE DE SANTA CATARINA E RESISTÊNCIA DOS AGENTES A ANTIMICROBIANOS

A bovinocultura de leite no Brasil vem crescendo ao longo dos anos, visto que em 2011 o país atingiu a produção de 21,6 bilhões de litros de leite, tendo as regiões Sudeste e Sul como maiores produtoras. Visando ao aumento na produtividade e considerando as características do relevo na região Oeste de Santa Catarina, tem-se aumentado o número de propriedades aderindo ao sistema de alojamento de bovinos em Free Stall, entretanto, os animais criados em galpões tornam-se mais suscetíveis às enfermidades em razão do maior contato e da alta carga microbiológica do ambiente. Entre essas enfermidades, destaca-se a mastite, que se trata do processo inflamatório da glândula mamária, geralmente de caráter infeccioso, caracterizada por alterações no leite e no tecido glandular, podendo ser classificada como clínica ou subclínica, ou ainda ser classificada de acordo com o agente causador em contagiosa ou ambiental. Com o objetivo de determinar a prevalência de agentes causadores de mastite em bovinos criados em sistema de alojamento Free Stall no Oeste de Santa Catarina e avaliar a resistência dos agentes aos principais antimicrobianos utilizados para tratamento dos casos de mastite, foram realizadas coletas de leite de animais positivos para o teste California Mastitis Test (CMT), selecionados por conveniência. As amostras foram enviadas para o laboratório de microbiologia da Universidade do Oeste de Santa Catarina (Unoesc), onde foram realizados os testes para a identificação dos agentes e teste de suscetibilidade aos antimicrobianos. Observou-se que o agente de maior prevalência foi Staphylococcus sp. coagulase negativa (38,56%) , seguido de Staphylococcus sp. coagulase positiva (11,76%), Enterococcus saccharolyticus (10,46%), Staphylococcus aureus (9,15%), Streptococcus uberis (4,58%), Acinetobacter sp. (3,27%), Enterobacter aerogenes (3,27%), Alcaligenes faecalis (2,61%), Aeromonas sp. (2,61%), Streptococcus acidominimus (2,61%) e 11,11% de outros microrganismos. Em relação ao teste de suscetibilidade aos antimicrobianos, constatou-se que os microrganismos Gram positivos isolados apresentaram sensibilidade aos seguintes antimicrobianos: Ceftiofur (98,36%), Enrofloxacina (97,54%), Amoxicilina + ácido clavulânico (95,90%), Ampicilina (94,26%), Eritromicina (90,16%), Sulfametoxazol + trimetoprim (88,52%), Penicilina (87,70%), Tetraciclina (80,33%), Gentamicina (77,04%), Neomicina (65,57%), Oxaciclina (59,84%) e Estreptomicina (40,16%). Já os microrganismos Gram negativos apresentaram sensibilidade à Enrofloxacina (96%), Norfloxacina (92%), Tetracilcina (88%), Ceftiofur (80%), Gentamicina (76%), Neomicina (72%), Sulfametoxazol + trimetoprim (68%), Estreptomicina (52%), Ampicilina (44%), Lincomicina (36%), Amocicilina (36%) e Oxacilina (12%). O agente de maior prevalência Staphylococcus coagulase negativa apresentou maior sensibilidade para Amoxicilina + ácido clavulânico (98,30%), seguido de Ceftiofur (96,61%) e enrofloxacina (96,61%), enquanto o Staphylococcus aureus apresentou 100% de sensibilidade para ceftiofur e enrofloxacina, seguido de ampicilina (92,85%). Dessa forma, enfatiza-se a importância da realização de testes para identificação dos agentes, bem como testes para verificar a susuctibilidade dos mesmos, a fim de realizar-se um correto tratamento e prevenção por meio de manejo adequado de acordo com cada situação.Palavras-chave: Free stall. Mastite. Antibiograma. Microrganismos

Influenza della microstruttura sulla resistenza a fatica di un acciaio sinterizzato al cromo prodotto con la polvere prelegata Astaloy CrL

Il comportamento a fatica di acciai sinterizzati al cromo, prodotti con la polvere base Astaloy CrL,è stato studiato in funzione della densità al verde, della temperatura di sinterizzazione e dellamicrostruttura, che varia con la percentuale di carbonio, con il trattamento di tempra o di cementazione.La cementazione è stata condotta sia in gas che in plasma, in impianti industriali ottimizzando i rispettiviparametri. La resistenza a fatica, determinata su campioni intagliati, aumenta poco con la temperaturadi sinterizzazione e molto di più con la densità al verde. Essa inoltre migliora passando da unamicrostruttura bainitica inferiore, ad una martensitica distesa. Con la cementazione, la resistenza a faticaaumenta ulteriormente. La differenza fra cementazione in plasma e cementazione in gas, malgradola migliore microstruttura degli strati superficiali, non è particolarmente marcata