Experimental investigation of precession driven flows in a triaxial ellipsoid

<p>Precession driven flows are relevant for geo- and astrophysical fluid dynamics as well as industrial applications. In the context of planetary core dynamics, they are attributed to the generation of magnetic fields and/or anomalous dissipation. While precession driven flows have been frequently studied in a cylindrical, spherical or spheroidal container shape, the geometry of a triaxial ellipsoid, representing the geophysical case of core mantle boundary deformation in a tidally locked planet, has received less attention.</p><p>Here, we present results from an experimental study in a triaxial ellipsoid. The main focus of our study is on the base flow of uniform vorticity and we report a good agreement between experimental data and existing semi-analytical models. The amplitude of the time averaged uniform vorticity displays a hysteresis loop as a function of the precession forcing and we demonstrate that this observation depends on the ellipticity of the container. Our study also comprises experiments where the boundary layer is expected to be in a turbulent state. Therefore, we discuss the applicability of an effective damping coefficient in the semi-analytical models to account for the dissipation in a turbulent boundary layer. </p>

Effect of container shape on freeze concentration of apple juice

Concentrating fruit juices by freezing supports the maintenance of both nutrients and flavors. Development of the freezing concentration process has introduced equipment such as centrifuge or block freezing systems, which are suitable for large-scale commercial processing. However, the necessary characteristics of freeze concentration methods for juices include simplicity and low cost. This study examined the effects of different container shapes on the processes of freezing and melting. The shape of the container was found to be more important than the melting temperature, across a relatively large scale. Furthermore, the nutrient procyanidin B2 and saccharides were concentrated. The methods concentrated juice components under low cost conditions without complex equipment. This research thus not only offers benefits for commercial juice preparation but also provides new insight into effects of shape differences in concentration technologies.

Scaling Effects on the Residual Thermomechanical Stress During Ice-Free Cooling to Storage Temperature

Cryopreservation via vitrification (glass formation) is a promising approach for long-term preservation of large-size tissues and organs. Unfortunately, thermomechanical stress, which is driven by the tendency of materials to change size with temperature, may lead to structural failure. This study focuses on analysis of thermomechanical stress in a realistic, pillow-like shape cryobag as it is cooled to cryogenic storage, subject to sufficiently high cooling rates to facilitate vitrification. Contrary to common perception, it is demonstrated in this study that the maximum stress in the specimen does not necessarily increase with increasing size of the specimen. In fact, the maximum stress is affected by the combination of two competing effects, associated with the extent of the temperature gradients within the specimen and its overall volume. On one hand, the increase in specimen size gives rise to more prominent temperature gradients, which can intensify the thermomechanical stress. On the other hand, the temperature distribution at the core of larger specimens is more uniform, which leads to a larger portion of the specimen transitioning from fluid to a glassy material almost instantaneously, which carries a moderating effect on the overall mechanical stress at the glassy state (i.e., lower residual stress). In conclusion, this study demonstrates the role of container shape optimization in reducing the thermomechanical stress during cooling.

The effect of age and vision on functional measures of medication management, across different prescription drug container shapes in persons with visual impairment

The relative effect of age and vision on medication management tasks (time and accuracy of entering the pharmacy phone number and interpreting dose) across four different prescription drug container shapes is examined. A mixed measures three-factor design was employed, with within-subject control. The repeated-measure independent variable of interest was container shape (four conditions), and the two between-subject independent variables were vision and age. Older age and decreased vision were found to be generally negatively associated with time and accuracy of entering the phone number and correct interpretation of dose. Container shape modified the effect of vision and age on the medication management tasks. Interactions between independent variables of age, vision, and container shape make it difficult to recommend one container shape for all participants. The results presented give credence for further examination of packing for label readability and other aspects of medication management, given the ease at which packaging can be modified.

Effect of the Lifting Velocity and Container Shape on Angle of Repose of Iron Ore Particles

To investigate the impact of lifting velocity and container shape on angle of repose, the fixed-base cylinder method was performed using three types of container shape. The container shape was lifted a series of lifting velocities. Six size fractions of iron ore particles ranging from coarser to fine particles were used as the test materials. And the sand-pile calibration method was then used to calibrate the contact parameters of iron ore particles. Results show angle of repose decreased exponentially with the lifting velocity, while it appeared approximately to be invariant to particle shape, for all size fractions. The sand pile highly depends on the container shape at a low lifting velocity but appears to be invariant to particle size for a high lifting velocity. And then a predictive equation is established and a very close agreement between the predicted and measured angle of repose is attained. Finally, a series of DEM simulations considering the irregular particle shape are conducted by means of sphere clump method to calibrate the contact parameters and are in good visual agreement with the experimental results, indicating the “tuned” contact parameters as well as the applicability of the predicted equation.

Tinggalan Batu Lumpang di Desa Ruko, Kecamatan Tobelo: Tinjauan Atas Konteks Sejarah dan Sosial Budaya Kerajaan-Kerajaan Lokal di Halmahera Utara

Batu Lumpang in the archaeological perspecitve is known as remains with the characteristic as a tool for mashing food . This stone has a container shape that made of stone vessels were notched in the middle. The purpose of this study is to initiate the prelimenary study of the batu lumpang in the Ruko village, the District Tobelo , North Halmahera and will be use as a data that assist the interpreationt and explaination on the history of North Halmahera. The research method adopted in this study is observation and interviews. Qualitative analysis and ethnoarchaeology analysis has been adopted to see the depth of the data to be interpreted. Results of the study shows that the factors of hegemony of the Ternate empire who conquered Moro and an abundance of food sources in Moro, as well as the strong indication of batu lumpang as the main supporting objects for the economic activity at that time.Batu lumpang dalam khasanah arkeologi dikenal sebagai tinggalan dengan ciri yang mengarah sebagai alat menumbuk makanan. Batu ini merupakan wadah yang berbentuk bejana terbuat dari batu yang berlekuk di tengahnya. Tujuan dari penelitian ini sebagai studi awal dalam melihat tinggalan batu lumpang yang ada di Desa Ruko Kec. Tobelo Kab. Halmahera Utara sebagai data yang membantu menginterpretasi dan menjelaskan sebuah peristiwa sejarah yang panjang di Halmahera Utara. Metode penelitian menggunakan observasi langsung dan wawancara. Analisis kualitatif dan analisis etnoarkeologi diperlukan untuk melihat kedalaman data yang hendak diinterpretasikan. Hasil dari penelitian adalah faktor hegemoni kekuasaan dari kerajaan Ternate yang menaklukkan kerajaan Moro dan berlimpahnya sumber bahan pangan di Moro menjadikan indikasi kuat batu lumpang sebagai penyokong aktivitas ekonomi pada kala itu.