Comparison of experimental and numerical sloshing loads in partially filled tanks

Sloshing phenomenon consists in the movement of liquids inside partially filled tanks, whichgenerates dynamic loads on the tank structure. Resulting impact pressures are of great importance in assessingstructural strength, and their correct evaluation still represents a challenge for the designer due to the highnonlinearities involved, with complex free surface deformations, violent impact phenomena and influence of airtrapping. In the present paper a set of two-dimensional cases for which experimental results are available areconsidered to assess merits and shortcomings of different numerical methods for sloshing evaluation, namely twocommercial RANS solvers (FLOW-3D and LS-DYNA), and two own developed methods (Smoothed ParticleHydrodynamics and RANS). Impact pressures at different critical locations and global moment induced by watermotion for a partially filled tank with rectangular section having a rolling motion have been evaluated and resultsare compared with experiments

Evaluación del perfil mineral, proteína bruta y extracto etéreo de dietas utilizadas en la producción porcina de la provincia de La Pampa

La formulación de dietas comerciales para cerdos implica la elección de los ingredientes alimenticios de menor costo para satisfacer las necesidades nutricionales del animal según la edad, genética, tamaño y etapa fisiológica. La producción porcina de la provincia de La Pampa se caracteriza por bajos índices productivos debido a la utilización ineficiente de ingredientes usados en la elaboración de raciones. El objetivo de este trabajo fue evaluar el perfil nutricional de las dietas suministradas en los establecimientos porcinos de la provincia de La Pampa, relacionándolo a los requerimientos nutricionales de las categorías animales establecidos por las tablas de referencia del Nutrient Requirements of Swine (2012). Se muestreó alimento de las categorías de recría (10-20 kg PV), desarrollo (20-50 kg PV), terminación (50-100 kg PV) y lactancia de 20 establecimientos porcinos seleccionados al azar, tanto intensivos como extensivos. Se analizó la composición proximal de los alimentos y se determinó el perfil multielemental de Ca, Co, Fe, K, Mg, Mn, Na, P, y Zn mediante espectrometría de emisión atómica con plasma inducido por microondas (MIP OES). La composición proximal de los alimentos analizados aportó niveles de energía y proteína bruta propicios para las categorías animales analizadas. Las concentraciones minerales encontradas no cubrieron los requerimientos nutricionales o fueron excesivos dependiendo de la etapa fisiológica. Sin embargo, los resultados obtenidos en el presente estudio representan información valiosa de control de la calidad nutricional para el sector porcino de la provincia. Aun así, se recomienda repetir la investigación con mayor número de observaciones, ya que las muestras obtenidas de los criaderos extensivos fueron muy variables en materia prima y origen de las mismas

Prototipe Alat Pengekstrak Kunyit Otomatis Menggunakan Aktuator Motor DC

Di dalam kunyit terdapat kurkuminoid dengan kandungan utama berupa kurkumin. Pada penelitian sebelumnya telah dibuat alat ukur kadar kurkuminoid portabel. Sebelum kadar kurkumin diukur, kunyit harus diekstrak dahulu. Oleh karena itu dalam penelitian ini dibuat prototipe alat pengekstrak kunyit otomatis. Alat pengesktrak otomatis terdiri dari motor DC sebagai komponen utama penumbuk kunyit. Setelah kunyit selesai ditumbuk maka mikrokontroler akan mengaktifkan solenoid valve sehingga cairan etanol keluar ke tempat penumbuk kunyit sehingga kunyit larut dalam etanol. Larutan ini kemudian diukur absorbansinya menggunakan alat ukur spektrofotometer. Hasil pengukuran kemudian dibandingkan dengan hasil pengekstrakan kunyit secara manual. Sampel kunyit yang diambil adalah satu ruas kunyit pada bagian pangkal, tengah dan ujung. Dari hasil pengukuran ekstraksi secara manual, ekstrak kunyit pada bagian pangkal mempunyai absorbansi sebesar 1,083, bagian tengah 0,888 dan bagian ujung 0,62. Hasil ekstraksi secara otomatis menunjukkan semakin lama penumbukan maka error absorbansi semakin kecil. Penumbukan selama 15 detik diperoleh error absorbansi sebesar 66,76% dan penumbukan selama 3 menit 26,87%. Dengan hasil ini maka dapat diketahui bahwa proses penumbukan optimal dalam waktu 5 menit. Dengan penambahan proses pelarutan maka total waktu yang dibutuhkan adalah sekitar 8 menit. Waktu proses pengekstrakan secara otomatis ini lebih singkat daripada proses pengekstrakan secara manual (15 menit)

Polineuropatía desmielinizante inflamatoria crónica como forma de presentación de lupus eritematoso sistémico

Se describe el caso de una mujer de 35 años que presenta polineuropatía desmielinizante inflamatoria crónica como compromiso neurológico en su diagnóstico inicial de lupus eritematoso sistémico (LES). Si bien el compromiso neurológico es de una prevalencia variable en lupus, la asociación que se describe no es frecuente y tiene importantes connotaciones en el tratamiento

Molecular MR Imaging of Liver Fibrosis: A Feasibility Study Using Rat and Mouse Models

Background & Aims: Liver biopsy, the current clinical gold standard for fibrosis assessment, is invasive and has sampling errors, and is not optimal for screening, monitoring, or clinical decision-making. Fibrosis is characterized by excessive accumulation of extracellular matrix proteins including type I collagen. We hypothesize that molecular magnetic resonance imaging (MRI) with a probe targeted to type I collagen could provide a direct and non-invasive method of fibrosis assessment. Methods: Liver fibrosis was induced in rats with diethylnitrosamine and in mice with carbon tetrachloride. Animals were imaged prior to and immediately following i.v. administration of either collagen-targeted probe EP-3533 or non-targeted control Gd-DTPA. Magnetic resonance (MR) signal washout characteristics were evaluated from T1 maps and T1-weighted images. Liver tissue was subjected to pathologic scoring of fibrosis and analyzed for gadolinium and hydroxyproline. Results: EP-3533-enhanced MR showed greater signal intensity on delayed imaging (normalized signal enhancement mice: control = 0.39 ± 0.04, fibrotic = 0.55 ± 0.03, p <0.01) and slower signal washout in the fibrotic liver compared to controls (liver t1/2 = 51.3 ± 3.6 vs. 42.0 ± 2.5 min, p <0.05 and 54.5 ± 1.9 vs. 44.1 ± 2.9 min, p <0.01 for fibrotic vs. controls in rat and mouse models, respectively). Gd-DTPA-enhanced MR could not distinguish fibrotic from control animals. EP-3533 gadolinium concentration in the liver showed strong positive correlations with hydroxyproline levels (r = 0.74 (rats), r = 0.77 (mice)) and with Ishak scoring (r = 0.84 (rats), r = 0.79 (mice)). Conclusions: Molecular MRI of liver fibrosis with a collagen-specific probe identifies fibrotic tissue in two rodent models of disease

A new device to measure the structural properties of the femuranterior cruciate ligament-tibia complex

Previous studies of biomechanical properties of femur-anterior cruciate ligamenttibia complex (FATC) utilized a wide variety of testing methodologies Introduction The anterior cruciate ligament (ACL) has a very complex anatomy which enables it to perform an important role in guiding knee motion. As the knee undergoes flexionextension, internal-external, and varus-valgus rotation, the length and orientation of the ACL change significantly. The broad attachments of the ACL to both the femur and the tibia allow various portions of the ligament to be relatively taut throughout a full range of knee motion. So, given a particular orientation of the knee, some collagen bundles of the ACL experience tension while other bundles are unloaded Previous studies of the biomechanical properties of the femur-ACL-tibia complexes (FATC) utilized knee orientations and loading directions which were poorly documented and seemingly arbitrary with respect to the ligament orientation relative to the direction of applied load. Thus, data are difficult to compare with one another. Viidik [5] investigated the structural properties of the FATC in rabbits with the knee in a fully extended position and with the femur, tibia, and ACL all aligned along the axis of the applied tensile load. Gupta et al. [6] used a similar experimental set up to test the FATC of canines, but with the tibia externally rotated 90 deg relative to the femur to eliminate the natural twist in the ACL. Noyes and Groo

Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics

To help understand the high activity of silver as an oxidation catalyst, e.g., for the oxidation of ethylene to epoxide and the dehydrogenation of methanol to formaldehyde, the interaction and stability of oxygen species at the Ag(111) surface has been studied for a wide range of coverages. Through calculation of the free energy, as obtained from density-functional theory and taking into account the temperature and pressure via the oxygen chemical potential, we obtain the phase diagram of O/Ag(111). Our results reveal that a thin surface-oxide structure is most stable for the temperature and pressure range of ethylene epoxidation and we propose it (and possibly other similar structures) contains the species actuating the catalysis. For higher temperatures, low coverages of chemisorbed oxygen are most stable, which could also play a role in oxidation reactions. For temperatures greater than about 775 K there are no stable oxygen species, except for the possibility of O atoms adsorbed at under-coordinated surface sites Our calculations rule out thicker oxide-like structures, as well as bulk dissolved oxygen and molecular ozone-like species, as playing a role in the oxidation reactions.Comment: 15 pages including 9 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Anti-cancer activities of allyl isothiocyanate and its conjugated silicon quantum dots

Allyl isothiocyanate (AITC), a dietary phytochemical in some cruciferous vegetables, exhibits promising anticancer activities in many cancer models. However, previous data showed AITC to have a biphasic effect on cell viability, DNA damage and migration in human hepatoma HepG2 cells. Moreover, in a 3D co-culture of HUVEC with pericytes, it inhibited tube formation at high doses but promoted this at low doses, which confirmed its biphasic effect on angiogenesis. siRNA knockdown of Nrf2 and glutathione inhibition abolished the stimulation effect of AITC on cell migration and DNA damage. The biological activity of a novel AITC-conjugated silicon quantum dots (AITC-SiQDs) has been investigated for the first time. AITC-SiQDs showed similar anti-cancer properties to AITC at high doses while avoiding the low doses stimulation effect. In addition, AITC-SiQDs showed a lower and long-lasting activation of Nrf2 translocation into nucleus which correlated with their levels of cellular uptake, as detected by the intrinsic fluorescence of SiQDs. ROS production could be one of the mechanisms behind the anti-cancer effect of AITC-SiQDs. These data provide novel insights into the biphasic effect of AITC and highlight the application of nanotechnology to optimize the therapeutic potential of dietary isothiocyanates in cancer treatment