165 research outputs found
On the coherence of synthetic turbulence generation methods
Synthetic turbulence generation methods have been extensively used by engineers and scientists in the past ten years in order to impose initial conditions in a wide range of turbulent flow problems.
The interest in synthetic methods relies in the fact that reliability of methodologies such as large eddy simulation (LES) or direct numerical simulation (DNS) strongly depends on how well the developed turbulence is characterized, which generally leads to computationally expensive simulations. In this work the methodology known as “modified discretizing and synthesizing random flow generation” (MDSRFG) jointly with a LES method is analyzed for its use in the study of bluff body aerodynamics. A comparison with other generation techniques, that are closely related by their features and their conceptual origins, is presented with particular emphasis on the correct representation of the coherence of the velocity field.
The resulting wind loads on the model, along with the statistical characteristics of the flow, show that the MDSRFG technique allows to represent a field of spatially correlated velocities correctly.Publicado en: Mecánica Computacional vol. XXXV, no. 18Facultad de Ingenierí
On the coherence of synthetic turbulence generation methods
Synthetic turbulence generation methods have been extensively used by engineers and scientists in the past ten years in order to impose initial conditions in a wide range of turbulent flow problems.
The interest in synthetic methods relies in the fact that reliability of methodologies such as large eddy simulation (LES) or direct numerical simulation (DNS) strongly depends on how well the developed turbulence is characterized, which generally leads to computationally expensive simulations. In this work the methodology known as “modified discretizing and synthesizing random flow generation” (MDSRFG) jointly with a LES method is analyzed for its use in the study of bluff body aerodynamics. A comparison with other generation techniques, that are closely related by their features and their conceptual origins, is presented with particular emphasis on the correct representation of the coherence of the velocity field.
The resulting wind loads on the model, along with the statistical characteristics of the flow, show that the MDSRFG technique allows to represent a field of spatially correlated velocities correctly.Publicado en: Mecánica Computacional vol. XXXV, no. 18Facultad de Ingenierí
Simulación computacional del cuerpo de Ahmed bajo distintos ángulos de incidencia de viento
En este trabajo se presenta el análisis computacional del flujo de viento alrededor del modelo simplificado conocido como “cuerpo de Ahmed”, bajo distintos ángulos de incidencia. La geometría estudiada del cuerpo corresponde a un ángulo de inclinación de cola de treinta y cinco grados. Se discute sobre la convergencia de mallado para las distintas configuraciones consideradas, las cuales corresponden a distintos ángulos de incidencia del viento sobre el cuerpo. La simulación computacional se lleva a cabo utilizando el código libre y abierto OpenFOAM (Open Field Operation and Manipulation). Se obtienen los coeficientes aerodinámicos, perfiles de velocidad, los cuales resultan concordantes con reportes experimentales de referencias bibliográficas específicas. Se realiza además un post-proceso para determinar las estructuras vorticosas y posterior análisis de la contribución de las distintas componentes del cuerpo en su formación.Publicado en: Mecánica Computacional vol. XXXV, no. 17Facultad de Ingenierí
Simulación computacional del cuerpo de Ahmed bajo distintos ángulos de incidencia de viento
En este trabajo se presenta el análisis computacional del flujo de viento alrededor del modelo simplificado conocido como “cuerpo de Ahmed”, bajo distintos ángulos de incidencia. La geometría estudiada del cuerpo corresponde a un ángulo de inclinación de cola de treinta y cinco grados. Se discute sobre la convergencia de mallado para las distintas configuraciones consideradas, las cuales corresponden a distintos ángulos de incidencia del viento sobre el cuerpo. La simulación computacional se lleva a cabo utilizando el código libre y abierto OpenFOAM (Open Field Operation and Manipulation). Se obtienen los coeficientes aerodinámicos, perfiles de velocidad, los cuales resultan concordantes con reportes experimentales de referencias bibliográficas específicas. Se realiza además un post-proceso para determinar las estructuras vorticosas y posterior análisis de la contribución de las distintas componentes del cuerpo en su formación.Publicado en: Mecánica Computacional vol. XXXV, no. 17Facultad de Ingenierí
Simulación computacional del cuerpo de Ahmed bajo distintos ángulos de incidencia de viento
En este trabajo se presenta el análisis computacional del flujo de viento alrededor del modelo simplificado conocido como “cuerpo de Ahmed”, bajo distintos ángulos de incidencia. La geometría estudiada del cuerpo corresponde a un ángulo de inclinación de cola de treinta y cinco grados. Se discute sobre la convergencia de mallado para las distintas configuraciones consideradas, las cuales corresponden a distintos ángulos de incidencia del viento sobre el cuerpo. La simulación computacional se lleva a cabo utilizando el código libre y abierto OpenFOAM (OpenField Operation and Manipulation). Se obtienen los coeficientes aerodinámicos, perfiles de velocidad, los cuales resultan concordantes con reportes experimentales de referencias bibliográficas específicas.Se realiza además un post-proceso para determinar las estructuras vorticosas y posterior análisis de la contribución de las distintas componentes del cuerpo en su formación.Publicado en: Mecánica Computacional vol. XXXV no.47Facultad de Ingenierí
Comparative abundance and diversity of Dryininae (Hymenoptera, Dryinidae) in three savannah phytophysiognomies in southeastern Brazil, under three sampling methods
Comparative abundance and diversity of Dryininae (Hymenoptera, Dryinidae) in three savannah phytophysiognomies in southeastern Brazil, under three sampling methods. This study aimed to assess the abundance and diversity of Dryininae in riparian vegetation, Brazilian savannah, and savannah woodland vegetation at the Estação Ecológica de Jataí, in Luiz Antônio, State of São Paulo, Brazil, by using Moericke, Malaise, and light traps. The sampling was carried out from December 2006 to November 2009, and 371 specimens of Dryininae were caught, with the highest frequencies in spring and summer. Fourteen species of Dryinus Latreille, 1804 and one of Thaumatodryinus Perkins, 1905 were identified. The highest frequencies of Dryinus in the riparian vegetation differed significantly from those obtained in the Brazilian savannah and savannah woodland vegetation. In the riparian vegetation, the highest number of Dryinus was collected using light traps and the interactions between abundance and the collection method used were significant. The number of specimens of Dryinus collected in the Brazilian savannah and savannah woodland vegetation using Malaise traps did not differ significantly from those obtained using Moericke traps. Males significantly outnumbered females in the sex ratio of Dryinus. The species diversity of Dryinus based on females collected using Malaise traps was high in the Brazilian savannah. Furthermore, high species richness of female Dryinus was observed in riparian vegetation (six species) and Brazilian savannah (five). The light trap was the most successful method for sampling diversity of Dryininae
Swine Carcass Condemnation in Commercial Slaughterhouses
ABSTRACT
Objective. The research was conducted to evaluate the main causes of carcass condemnation, as well as the financial loss caused by it, at a commercial slaughterhouse located in Dourados, MS, Brazil. Materials and methods. The data related to carcass condemnation, for the years 2007 to 2009 was obtained from a commercial slaughterhouse, located in the city of Dourados, MS, Brazil, and turned into a percentage of the total number of animals slaughtered during that period. The most frequent causes of carcass condemnation (total or partial) were grouped into classes (pleurisy + pneumonia; enteritis; arthritis; abscesses; fractures/hematomas + contusions + death). The financial loss by the slaughterhouse was estimated using the condemnation data. Results. The total rate of carcass condemnation was low and tended to stability (<0.45%). The most prevalent causes of condemnation during the study period were abscesses and death in the transport, which together accounted for approximately 40% of all condemnation. The condemnation due to health problems tended to decrease or to be stable over the years. However, the condemnations caused by management problems (abscesses, fractures, contusions and death) showed a significant increase. The average loss to the integrative company according to the carcasses condemnation was exceeding U$1,600,000.00 in the years studied. Conclusions. The main causes of carcass condemnation come from management failure. The annual loss by the company can be invested in the training of manpower in order to reduce the rates of carcass condemnation
Bone Characteristics of Broilers Supplemented with Vitamin D Author(s)
ABSTRACT Vitamin D is added to broiler diets to supply its physiological requirement for bone formation. The fast growth rate of modern broilers is often associated with poor bone formation. Increasing vitamin D supplementation levels and the use of more available sources have applied to try to prevent leg problems, to increase carcass yield, and to improve the performance of broilers. The present study evaluated three vitamin D supplementation levels (1) 3,500 IU (control); (2) control + 1,954 IU of 25-hydroxycholecalciferol; and (3) control + 3,500 IU of vitamin D in broiler diets supplied up to 21 days of age. The objective was to investigate if the vitamin D levels above the recommendations could reduce leg problems in broilers. In this experiment, a total of 1,296 oneday-old male and female Cobb® 500 broilers were used. A 2 x 3 factorial arrangement was applied, consisting of two sexes and three vitamin D levels. No difference was found between the levels of vitamin D (p > 0.05), the performance of males or females, the gait score, the valgus and varus incidence, the tibial dyschondroplasia incidence, the occurance of femoral degeneration, the bone colorimetric, and the carcass yield. Parts yield differences were found (p > 0.05), except for liver and intestine yields. We concluded that the lowest tested vitamin D level (3,500 IU per kilogram of feed) added to the diet was the best choice in terms of cost/ benefit to help minimizing leg problems in broilers
Application of PEG400 in the one-pot synthesis of 7-[4-alkyl- or (hetero) aryl-1H-1,2,3-triazol-1-yl]thieno[3,2-b]pyridines via SNAr and Cu(I)- Catalyzed Azide-Alkyne Cycloaddition and preliminary evaluation of their anti-tumour activity
Several novel 7-[4-alkyl- or (hetero)aryl-1H-1,2,3-triazol-1-yl]thieno[3,2-b]pyridines were prepared in
good to high yields, using the environmentally friendly solvent PEG400 in a one-pot procedure from 7-
chlorothieno[3,2-b]pyridine to form the corresponding azide via SNAr with NaN3, followed by Cu(I)-catalyzed
Azide-Alkyne Cycloaddition (CuAAC) using different types of alkynes. This one-pot reaction in
PEG400 starting from a halogenated heteroaromatic system is reported for the first time and demonstrated
a wide scope of application for alkynes. Preliminary anti-tumour activity on human tumour cell
lines using the prepared 1,4-di(hetero)aryl-1,2,3-triazoles was evaluated, together with their toxicity in
non-tumour cells. Among the tested compounds the most promising one was a 2-ethynylpyridine
derivative.Fundação para a Ciência e Tecnologia (FCT)–Portugal financially
supports CQUM (UID/QUI/686/2019), CIMO-IPBragança (UID/
AGR/690/2019), the research project PTDC/QUI-QFI/28020/2017
(POCI-01-0145-FEDER-028020) also financed by European Regional Development Fund (ERDF), COMPETE2020 and Portugal2020,
the PTNMR network also supported by Portugal2020
and the PhD grant of J.M.R. (SFRH/BD/115844/2016) also financed
by ESF (European Social Fund) and HCOP (Human Capital Operational
Programme).info:eu-repo/semantics/publishedVersio
YES1 drives lung cancer growth and progression and predicts sensitivity to dasatinib
Rationale: The characterization of new genetic alterations is essential to assign effective personalized therapies in non–small cell lung cancer (NSCLC). Furthermore, finding stratification biomarkers is essential for successful personalized therapies. Molecular alterations of YES1, a member of the SRC (proto-oncogene tyrosine-protein kinase Src) family kinases (SFKs), can be found in a significant subset of patients with lung cancer.
Objectives: To evaluate YES1 (v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1) genetic alteration as a therapeutic target and predictive biomarker of response to dasatinib in NSCLC.
Methods: Functional significance was evaluated by in vivo models of NSCLC and metastasis and patient-derived xenografts. The efficacy of pharmacological and genetic (CRISPR [clustered regularly interspaced short palindromic repeats]/Cas9 [CRISPR-associated protein 9]) YES1 abrogation was also evaluated. In vitro functional assays for signaling, survival, and invasion were also performed. The association between YES1 alterations and prognosis was evaluated in clinical samples.
Measurements and Main Results: We demonstrated that YES1 is essential for NSCLC carcinogenesis. Furthermore, YES1 overexpression induced metastatic spread in preclinical in vivo models. YES1 genetic depletion by CRISPR/Cas9 technology significantly reduced tumor growth and metastasis. YES1 effects were mainly driven by mTOR (mammalian target of rapamycin) signaling. Interestingly, cell lines and patient-derived xenograft models with YES1 gene amplifications presented a high sensitivity to dasatinib, an SFK inhibitor, pointing out YES1 status as a stratification biomarker for dasatinib response. Moreover, high YES1 protein expression was an independent predictor for poor prognosis in patients with lung cancer.
Conclusions: YES1 is a promising therapeutic target in lung cancer. Our results provide support for the clinical evaluation of dasatinib treatment in a selected subset of patients using YES1 status as predictive biomarker for therapy
- …