A Study For Efficiently Solving Optimisation Problems With An Increasing Number Of Design Variables

Coupling optimisation algorithms to Finite Element Methods (FEM) is a very promising way to achieve optimal metal forming processes. However, many optimisation algorithms exist and it is not clear which of these algorithms to use. This paper investigates the sensitivity of a Sequential Approximate Optimisation algorithm (SAO) proposed in [1-4] to an increasing number of design variables and compares it with two other algorithms: an Evolutionary Strategy (ES) and an Evolutionary version of the SAO (ESAO). In addition, it observes the influence of different Designs Of Experiments used with the SAO. It is concluded that the SAO is very capable and efficient and its combination with an ES is not beneficial. Moreover, the use of SAO with Fractional Factorial Design is the most efficient method, rather than Full Factorial Design as proposed in [1-4]

Nanoporous Anodic Alumina Photonic Crystals for Optical Chemo- and Biosensing: Fundamentals, Advances, and Perspectives

Optical sensors are a class of devices that enable the identification and/or quantification of analyte molecules across multiple fields and disciplines such as environmental protection, medical diagnosis, security, food technology, biotechnology, and animal welfare. Nanoporous photonic crystal (PC) structures provide excellent platforms to develop such systems for a plethora of applications since these engineered materials enable precise and versatile control of light–matter interactions at the nanoscale. Nanoporous PCs provide both high sensitivity to monitor in real-time molecular binding events and a nanoporous matrix for selective immobilization of molecules of interest over increased surface areas. Nanoporous anodic alumina (NAA), a nanomaterial long envisaged as a PC, is an outstanding platform material to develop optical sensing systems in combination with multiple photonic technologies. Nanoporous anodic alumina photonic crystals (NAA-PCs) provide a versatile nanoporous structure that can be engineered in a multidimensional fashion to create unique PC sensing platforms such as Fabry–Pérot interferometers, distributed Bragg reflectors, gradient-index filters, optical microcavities, and others. The effective medium of NAA-PCs undergoes changes upon interactions with analyte molecules. These changes modify the NAA-PCs’ spectral fingerprints, which can be readily quantified to develop different sensing systems. This review introduces the fundamental development of NAA-PCs, compiling the most significant advances in the use of these optical materials for chemo- and biosensing applications, with a final prospective outlook about this exciting and dynamic field

Integrating surface plasmon resonance and slow photon effects in nanoporous anodic alumina photonic crystals for photocatalysis

This study explores the potential of gold-coated titania-functionalized nanoporous anodic alumina distributed Bragg reflectors (Au-TiO2-NAA-DBRs) as platforms to enhance photocatalytic reactions by integrating “slow photons” and surface plasmon resonance (SPR). The photocatalytic degradation rate of methylene blue – a model organic compound with a well-defined absorption band in the visible spectral region – by these composite photonic crystals (PCs) upon visible-NIR light irradiation is used as an indicator to identify coupling effects between the “slow photon” effect and SPR. Our study demonstrates that the photocatalytic enhancement in Au-TiO2-NAA-DBRs is strongly associated with “slow photon” effect, while the contribution of SPR to the overall photocatalytic enhancement is weak due to the localized generation of surface plasmons on the top surface of the composite PC structure. Photocatalytic enhancement is optimal when the characteristic photonic stopband of these PCs partially overlaps with the absorption band of methylene blue, which results in edges being positioned away from the absorption maximum of the organic dye. The overall photocatalytic degradation for methylene blue is also correlated to the type of noble metal coating and the geometric features of the PC structures. These results establish a rationale for further development of noble metal-coated NAA-based hybrid plasmonic–photonic crystal photocatalyst platforms to optimally integrate “slow photons” and SPR for enhancing the efficiency of photocatalytic reactions and other light harvesting applications.Related: [http://cer.ihtm.bg.ac.rs/handle/123456789/3007]This is peer-reviewed version of the article: Law, L. Liu, M. Markovic, A. D. Abell and A. Santos, Catalysis Science & Technology, 2019, 9, 12, 3158-3176 [https://dx.doi.org/10.1039/C9CY00627C

La obesidad y su asociación con los demás factores de riesgo cardiovascular en escolares de Itapetininga, Brasil

BACKGROUND: Paucity of data on childhood obesity and cardiovascular risk in Brazil. OBJECTIVE: To determine the prevalence of hypertension, dyslipidemia, obesity and their correlations in a sample of school children in Itapetininga, State of São Paulo, Brazil. METHODS: Cross-sectional study with systematic collection of anthropometric data (weight, height, waist circumference, BMI and blood pressure levels) and determination of glucose, total cholesterol, LDL, HDL, uric acid, and apolipoproteins A and B in a random sample representative of school children from the public education system in Itapetininga, State of São Paulo. For data analysis, we used population parameters from the NCHS curves (2000), blood pressure categories from NHBPEP (2004), and the serum cholesterol levels proposed by the AHA for children and adolescents (2003). RESULTS: A total of 494 children and adolescents participated in the study. Of these, 11.7% had HBP, 51% increased total cholesterol, 40.5% increased LDL-cholesterol, 8.5% increased triglycerides, and 6.1% low HDL-cholesterol levels. Mean (± standard deviation) TC, HDL-cholesterol, LDL-cholesterol and triglycerides were 172.1(27.9), 48.1(10.0), 105.7(23.1) and 90.9(43.8), respectively. Obesity and overweight were detected in 12.8% and 9.7% of the sample, respectively. Individuals of the obese group had a greater chance of presenting with dyslipidemia and hypertension in comparison with those of the other groups. CONCLUSION: This study supports the hypothesis of different prevalences of excess weight among school children from the public education system of the northeastern and southeastern regions of Brazil, with higher rates in the latter. Additionally, it demonstrates an association of obesity with dyslipidemia and hypertension in that group. In light of the paucity of Brazilian data on this issue, our study provides important data for further comparisons.FUNDAMENTO: La escasez de datos sobre la obesidad infantil y el riesgo cardiovascular en Brasil. OBJETIVO: Determinar la prevalencia de hipertensión, dislipidemia, obesidad y sus correlaciones en una muestra de escolares de Itapetininga-SP. MÉTODOS: Corte transversal con recolección sistematizada de datos antropométricos (peso, altura, cintura, índice de masa corporal y niveles de presión) y dosificaciones de glucosa, colesterol (total y fracciones), ácido úrico y apolipoproteína A y B, en una muestra aleatoria, representativa de escolares del sistema público de Itapetininga-SP. Análisis de los datos utilizando parámetros poblacionales de las curvas del NCHS (2000), categorías de presión arterial del NHBPEP(2004) y categorías de los niveles séricos de colesterol propuestos por la AHA para niños y adolescentes (2003). RESULTADOS: Un total de 494 niños y adolescentes participaron en el estudio. De los participantes, el 11,7% presentó HAS, el 51% presentó aumento del colesterol total, el 40,5% presentó aumento del LDL-colesterol, el 8,5% presentó aumento de los triglicéridos y el 6,1% tuvieron valores bajos de HDL-colesterol. Los promedios (+desviación estándar) del CT, HDL-colesterol, LDL-colesterol y triglicéridos fueron respectivamente 172,1 (27,9), 48,1 (10,0), 105,7 (23,1) y 90,9 (43,8). La obesidad y el sobrepeso se detectaron en el 12,8% y el 9,7% de la muestra, teniendo en cuenta que la obesidad determinó una mayor probabilidad de detectarse la dislipidemia y la hipertensión cuando comparada con los demás grupos. CONCLUSIÓN: Este estudio suministra los argumentos a la hipótesis de una distinta prevalencia de exceso de peso entre escolares del sistema público de las regiones nordeste y sudeste, hallándose mayor en ésta última. Adicionalmente, demuestra una asociación de la obesidad con la dislipidemia y la hipertensión en aquel grupo. Ante la condición incipiente de los datos en el Brasil sobre la cuestión estudiada, nuestro trabajo suministra importantes datos para futuras comparaciones.FUNDAMENTO: A escassez de dados sobre a obesidade infantil e o risco cardiovascular no Brasil. OBJETIVO: Determinar a prevalência de hipertensão, dislipidemia, obesidade e suas correlações em uma amostra de escolares de Itapetininga-SP. MÉTODOS: Corte transversal com coleta sistematizada de dados antropométricos (peso, altura, cintura, índice de massa corporal e níveis pressóricos) e dosagens de glicose, colesterol (total e frações), ácido úrico e apolipoproteina A e B, em uma amostra aleatória, representativa de escolares da rede pública de Itapetininga-SP. Análise dos dados utilizando parâmetros populacionais das curvas do NCHS(2000), categorias de pressão arterial do NHBPEP(2004) e categorias dos níveis séricos de colesterol propostos pela AHA para crianças e adolescentes(2003). RESULTADOS: Um total de 494 crianças e adolescentes participaram do estudo. Dos participantes, 11,7% apresentaram HAS, 51% apresentaram aumento do colesterol total, 40,5% apresentaram aumento do LDL-colesterol, 8,5% apresentaram aumento dos triglicérides e 6,1% tiveram valores baixos de HDL-colesterol. As médias (±desvio padrão) do CT, HDL-colesterol, LDL-colesterol e triglicérides foram respectivamente 172,1(27,9), 48,1(10,0), 105,7(23,1) e 90,9(43,8). A obesidade e o sobrepeso foram detectados em 12,8% e 9,7% da amostra, sendo que a obesidade determinou uma maior chance de se detectar a dislipidemia e a hipertensão quando comparada com os demais grupos. CONCLUSÃO: Este estudo fornece subsídios para a hipótese de uma distinta prevalência de excesso de peso entre escolares da rede pública das regiões nordeste e sudeste, maior nesta última. Adicionalmente, demonstra uma associação da obesidade com a dislipidemia e a hipertensão naquele grupo. Diante da incipiência de dados no Brasil sobre a questão estudada, o nosso trabalho fornece dados importantes para futuras comparações.Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasUniversidade Federal de São Paulo (UNIFESP) Departamento de MedicinaUNIFESP, Depto. de MedicinaSciEL

A benchmark for validation of numerical results in sheet metal forming

Advances in FE codes for simulation of sheet metal forming processes have enabled its use during pre-production stage of a component. Some of recent developments include improvements and implementation of new material models of mechanical behaviour. However, these developments and corresponding results need to be validated, which means being compared with experimental results. On the other hand, in order that experimental results are a reference data, they need to be tested to repeatability and need to be obtained with such characteristic preferably by different institutions.http://www.sciencedirect.com/science/article/B6TGJ-4CS4NXC-M/1/11b425ff3006b6fcdad85f1f6b4fa57

Star Formation Rates from [C II] 158 μm and Mid-infrared Emission Lines for Starbursts and Active Galactic Nuclei

A summary is presented for 130 galaxies observed with the Herschel Photodetector Array Camera and Spectrometer instrument to measure fluxes for the [C II] 158 μm emission line. Sources cover a wide range of active galactic nucleus to starburst classifications, as derived from polycyclic aromatic hydrocarbon strength measured with the Spitzer Infrared Spectrograph. Redshifts from [C II] and line to continuum strengths (equivalent width (EW) of [C II]) are given for the full sample, which includes 18 new [C II] flux measures. Calibration of L([C II)]) as a star formation rate (SFR) indicator is determined by comparing [C II] luminosities with mid-infrared [Ne II] and [Ne III] emission line luminosities; this gives the same result as determining SFR using bolometric luminosities of reradiating dust from starbursts: log SFR = log L([C II)]) - 7.0, for SFR in M ⊙ yr-1 and L([C II]) in L ⊙. We conclude that L([C II]) can be used to measure SFR in any source to a precision of ~50%, even if total source luminosities are dominated by an active galactic nucleus (AGN) component. The line to continuum ratio at 158 μm, EW([C II]), is not significantly greater for starbursts (median EW([C II]) = 1.0 μm) compared to composites and AGNs (median EW([C II]) = 0.7 μm), showing that the far-infrared continuum at 158 μm scales with [C II] regardless of classification. This indicates that the continuum at 158 μm also arises primarily from the starburst component within any source, giving log SFR = log νL ν(158 μm) - 42.8 for SFR in M ⊙ yr-1 and νL ν(158 μm) in erg s-1

A far-infrared spectroscopic survey of intermediate redshift (ultra) luminous infrared galaxies

We present Herschel far-IR photometry and spectroscopy as well as ground-based CO observations of an intermediate redshift (0.21 _ z _ 0.88) sample of Herschel-selected (ultra)-luminous infrared galaxies (LIR >1011.5 L_). With these measurements, we trace the dust continuum, far-IR atomic line emission, in particular [C ii] 157.7μm, as well as the molecular gas of z ∼ 0.3 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) and perform a detailed investigation of the interstellar medium of the population. We find that the majority of Herschel-selected intermediate redshift (U)LIRGs have LCii/LFIR ratios that are a factor of about 10 higher than that of local ULIRGs and comparable to that of local normal and high-z star-forming galaxies. Using our sample to bridge local and high-z [C ii] observations, we find that the majority of galaxies at all redshifts and all luminosities follow an LCii−LFIR relation with a slope of unity, from which local ULIRGs and high-z active-galactic-nucleus-dominated sources are clear outliers.We also confirm that the strong anti-correlation between the LCii/LFIR ratio and the far-IR color L60/L100 observed in the local universe holds over a broad range of redshifts and luminosities, in the sense that warmer sources exhibit lower LC ii/LFIR at any epoch. Intermediate redshift ULIRGs are also characterized by large molecular gas reservoirs and by lower star formation efficiencies compared to that of local ULIRGs. The high LC ii/LFIR ratios, the moderate star formation efficiencies (LIR/L _COor LIR/MH2 ), and the relatively low dust temperatures of our sample (which are also common characteristics of high-z star-forming galaxies with ULIRG-like luminosities) indicate that the evolution of the physical properties of (U)LIRGs between the present day and z > 1 is already significant by z ∼ 0.3

Could thermal fluctuations seed cosmic structure?

We examine the possibility that thermal, rather than quantum, fluctuations are responsible for seeding the structure of our universe. We find that while the thermalization condition leads to nearly Gaussian statistics, a Harrisson-Zeldovich spectrum for the primordial fluctuations can only be achieved in very special circumstances. These depend on whether the universe gets hotter or colder in time, while the modes are leaving the horizon. In the latter case we find a no-go theorem which can only be avoided if the fundamental degrees of freedom are not particle-like, such as in string gases near the Hagedorn phase transition. The former case is less forbidding, and we suggest two potentially successful ``warming universe'' scenarios. One makes use of the Phoenix universe, the other of ``phantom'' matter.Comment: minor corrections made, references added, matches the version accepted to PR

Rational Management of Photons for Enhanced Photocatalysis in Structurally-Colored Nanoporous Anodic Alumina Photonic Crystals

A comprehensive study on the engineering of titanium dioxide-functionalized nanoporous anodic alumina distributed Bragg reflectors (TiO2–NAA-DBRs) for photocatalysis enhanced by the “slow photon” effect is presented. The photocatalytic performance of these composite photonic crystals (PCs) is assessed by monitoring photodegradation of a variety of organic molecules with absorbance bands across the spectral regions. This study demonstrates that photocatalytic performance of TiO2–NAA-DBRs is enhanced by the “slow photon” effect when the edges of the PC’s photonic stopband (PSB) fall within the absorbance band of the organic molecules. The photocatalytic performance is significantly enhanced when the PSB’s red edge is in close proximity to the absorbance band of the organic molecules. Overall photocatalytic degradation is also dependent on the total pore length of the PC structure, charge of the organic molecules, percentage of vis–near-IR irradiation, and matrix complexity (i.e., interfering ions and molecules) when the PC’s PSB is partially or entirely misaligned with respect to the absorbance band of the organic molecules. Finally, the real-life application of TiO2–NAA-DBRs to degrade pollutants such as pesticides in environmental matrices is demonstrated. This study provides new insights into the development of rationally engineered, high-performing, safe, and reusable photocatalyst systems.This is peer-reviewed version of the article: ACS Applied Energy Materials, 2019, 2, 2, 1169-1184, [https://doi.org/10.1021/acsaem.8b01721][http://cer.ihtm.bg.ac.rs/handle/123456789/2988