The objective of this study was to improve the energy management of an overhead downward flow (ODF)-type data center (DC) using the evaporative cooling method. A computational fluid dynamics (CFD) ...approach was used to predict the optimal operating condition of an A1-grade DC exhibiting the smallest entropy generation rate of the ODF system. Experiments were performed to validate the predicted airflow speed at the inlet of each server and temperature distributions at the inlet and outlet of each server. Furthermore, three thermal performance metrics, namely rack cooling index (RCI), return temperature index (RTI), and supply heat index (SHI), were used to compare the numerical and experimental results, which were found to be consistent. The measured power usage effectiveness (PUE) reached 1.42, significantly lower than the global average PUE of 1.55 reported in 2022. Moreover, using the CFD method, water mist was added at the air supply port to reduce the temperature of air from 21.63 °C to 18 °C via evaporation and increase relative humidity from 50% to 70%. These results suggest that evaporative cooling has the potential to facilitate the supplied air to provide additional cooling capacity and lower the chiller load to reduce energy consumption in the DC.
Introduction
Osteoblasts and osteoclasts are cells of osteoblastic origin, and are vital in homeostasis of the skeleton. miRs are important for functioning, survival and differentiation of ...osteoclasts. It has been reported previously that miR-23b-3p is involved in osteoporosis and in regulation of differentiation of osteoblasts. It is also involved in the process of bone formation. However, the role of miR-23b-3p in differentiation of osteoclasts remains unexplored.
Material and methods
CSF-1 and ODF induced osteoclasts were used for the study. RNA isolation was done from TIB-71 cells. TRAP staining was done for TRAP-positive osteoclast formation. PIT assay for bone resorption was performed. For in vivo studies osteoclast-specific miR-23b-3p transgenic mice were developed.
Results
The levels of miR-23b-3p were upregulated in bone marrow monocytes during osteoclastogenesis with colony stimulating factor-1 and osteoclast differentiation factor induction, which suggests that miR-23b-3p plays a crucial role in differentiation of osteoclasts. Over-expression of miR-23b-3p in bone marrow monocytes leads to osteoclastogenesis, whereas the inhibition ameliorates it. We further studied the function of miR-23b-3p via PI3K/AKT targeting the PTEN pathway. In vivo, osteoclast-specific miR-23b-3p transgenic mice showed suppressed PTEN and elevated osteoclast activity, and the mice showed decreased bone mineral density.
Conclusions
The results suggest that miR-23b-3p regulates the differentiation of osteoclasts by targeting PTEN through the PI3K/AKT cascade.
Debye–Scherrer patterns, obtained from X‐ray diffraction experiments using synchrotron light in transmission geometry, were analysed to construct generalized pole figures, and further used as input ...for an orientation distribution function inversion algorithm. By using Langford's method for separating strain and size contributions to peak broadening, it was possible, for the first time, to obtain full domain size and dislocation density generalized distribution functions (GDFs). This method was applied to cold‐rolled and annealed interstitial‐free steel. The predictions made using GDFs were corroborated by electron backscatter diffraction measurements and were also consistent with what was previously known for this kind of material under these conditions.
Debye–Scherrer patterns, obtained from X‐ray diffraction experiments using synchrotron light in transmission geometry, were analysed to construct generalized pole figures. Generalized orientation distribution functions of cold‐rolled and then annealed interstitial‐free steel were obtained to investigate microstructure developments in this material.
In this paper, we propose a novel large deformation diffeomorphic registration algorithm to align high angular resolution diffusion images (HARDI) characterized by orientation distribution functions ...(ODFs). Our proposed algorithm seeks an optimal diffeomorphism of large deformation between two ODF fields in a spatial volume domain and at the same time, locally reorients an ODF in a manner such that it remains consistent with the surrounding anatomical structure. To this end, we first review the Riemannian manifold of ODFs. We then define the reorientation of an ODF when an affine transformation is applied and subsequently, define the diffeomorphic group action to be applied on the ODF based on this reorientation. We incorporate the Riemannian metric of ODFs for quantifying the similarity of two HARDI images into a variational problem defined under the large deformation diffeomorphic metric mapping framework. We finally derive the gradient of the cost function in both Riemannian spaces of diffeomorphisms and the ODFs, and present its numerical implementation. Both synthetic and real brain HARDI data are used to illustrate the performance of our registration algorithm.
Two of the microstructural parameters most influential in the properties of polycrystalline materials are grain size and crystallographic texture. Although both properties have been extensively ...studied and there are a wide range of analysis tools available, they are generally considered independently, without taking into account the possible correlations between them. However, there are reasons to assume that grain size and orientation are correlated microstructural state variables, as they are the result of single microstructural formation mechanisms occurring during material processing. In this work, the grain size distribution and orientation distribution functions are combined in a single multivariate grain size orientation distribution function (GSODF). In addition to the derivation of the function, several examples of practical applications to low carbon steels are presented, in which it is shown how the GSODF can be used in the analysis of 2D and 3D electron backscatter diffraction data, as well as in the generation of representative volume elements for full‐field models and as input in simulations using mean‐field methods.
Grain size distribution and orientation distribution functions are combined in a single multivariate continuous grain size orientation distribution function (GSODF). Several examples of practical applications to low carbon steels are presented, in which it is shown how the GSODF can be used in the analysis of 2D and 3D electron backscatter diffraction data, and as input in full‐field and mean‐field crystal plasticity simulations.
The receptor activator of nuclear factor kappa-B ligand (RANKL)-RANK-osteoprotegerin (OPG) system is critical to bone homeostasis, but genetically deficient mouse models have revealed important roles ...in the immune system as well. RANKL-RANK-OPG is particularly important to T cell biology because of its organogenic control of thymic development and secondary lymphoid tissues influence central T cell tolerance and peripheral T cell function. RANKL-RANK-OPG cytokine-receptor interactions are often controlled by regulation of expression of RANKL on developing T cells, which interacts with RANK expressed on some lymphoid tissue cells to stimulate key downstream signaling pathways that affect critical tuning functions of the T cell compartment, like cell survival and antigen presentation. Activation of peripheral T cells is regulated by RANKL-enhanced dendritic cell survival, and dysregulation of the RANKL-RANK-OPG system in this context is associated with loss of T cell tolerance and autoimmune disease. Given its broader implications for immune homeostasis and osteoimmunology, it is critical to further understand how the RANKL-RANK-OPG system operates in T cell biology.
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•A new ODF to represent the orientation distribution of diffusion coefficients.•An analytical expression is derived to calculate the new ODF.•An efficient computation method DCODT is ...designed to reconstruct the new ODF.•The new method has superior capability for high b-values.
Diffusion magnetic resonance imaging (dMRI) is a popular non-invasive imaging technique applied for the study of nerve fibers in vivo, with diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI) as the commonly used dMRI methods. However, DTI cannot resolve complex fiber orientations in a local area and HARDI lacks a solid physical basis.
We introduce a diffusion coefficient orientation distribution function (DCODF). It has a clear physical meaning to represent the orientation distribution of diffusion coefficients for Gaussian and non-Gaussian diffusion. Based on DCODF, we then propose a new HARDI method, termed as diffusion coefficient orientation distribution transform (DCODT), to estimate the orientation distribution of nerve fibers in voxels.
The method is verified on the simulated data, ISMRM-2015-Tracto-challenge data, and HCP datasets. The results show the superior capability of DCODT in resolving the complex distribution of multiple fiber bundles effectively.
The method is compared to other common model-free HARDI estimators. In the numerical simulations, DCODT achieves a better trade-off between the resolution and accuracy than the counterparts for high b-values. In the comparisons based on the challenge data, the improvement of DCODT is significant in scoring. The results on the HCP datasets show that DCODT provides fewer spurious lobes in the glyphs, resulting in more coherent fiber orientations.
We conclude that DCODT may be a reliable method to extract accurate information about fiber orientations from dMRI data and promising for the study of neural architecture.
The contractile strain ratio (CSR) is an important property and a quality control factor of cold‐worked and stress‐relieved Ti–3Al–2.5V tubing. In this work, the CSR values of three thin‐walled ...Ti–3Al–2.5V tubing samples were obtained by uniaxial tensile tests, and the crystallographic textures of the tubing samples were characterized by orientation distribution functions (ODFs) which were determined on the basis of a series of pole figures obtained by X‐ray diffraction. A quantitative method is proposed for exploring the correlation between the CSR values and the ODF data of the tubing samples, including the following steps: Firstly, taking advantage of the ODF data, the volume fraction (V%) of crystallites that lie within a certain range of Euler angles (ϕ1, Φ, ϕ2) can be calculated, and the calculation is performed on each set of Euler angles (ϕ1, Φ, ϕ2). Secondly, each V% is resolved into an effective fraction in the orientation of the ideal radial texture {0002}⟨100⟩ corresponding to the Euler angles of (0, 0, 0), and the equivalent radial texture (ERT) is obtained as the sum of all such effective fractions. Thirdly, similarly to the previous step, the equivalent tangential texture (ETT) is calculated. The CSR will be related to the ratio of the ERT to the ETT, named the equivalent texture ratio (ETR). The CSR values of the tubing samples are 1.38, 1.96 and 2.19 and their ETR values are 1.33, 1.72 and 1.87, respectively. In particular, the CSR and the ETR of the tubing with a random distribution of the basal poles in the radial–tangential plane are both unity. It is found from the above data that the CSR increases approximately linearly with the ETR. Since the three‐dimensional orientations of crystallites and the orientation distributions throughout the Euler space are taken into account in the calculations of the ETR, the proposed method can be used for predicting and explaining the mechanical anisotropy of Ti–3Al–2.5V tubing more accurately.
Based on measurements of the contractile strain ratio (CSR) and the textures of three thin‐walled Ti–3Al–2.5V tubing samples, a quantitative method is proposed for exploring the correlation between the CSR values and the orientation distribution function data of the tubing samples.
Pole figure measurements with an X‐ray texture goniometer equipped with a point detector are rather time consuming: depending on the angular resolution to be recorded, of the order of several hours ...per pole figure. Conventionally, the pole hemisphere is scanned along latitudinal small circles according to a regular grid of constant step sizes in both the azimuthal and the polar angle. In the case of sharp textures an adaptive successive local refinement strategy of the pole hemisphere may offer a better performance in less time. Then the measurement positions of the grid are highly irregularly distributed over the pole hemisphere. To avoid erratic movements when turning the specimen, the scanning order is optimized by means of resolving a travelling salesman problem such that the total travelling time is minimized. Several algorithms are described resolving the travelling salesman problem with respect to the irregular grid to be applied for each pole figure and for each step of successive refinement. A practical application to pole figure measurements exposes total savings of about 1/8 compared to the conventional scanning order. Successive local refinement of the experimental design and optimization of the order of its measurement positions are well suited to the purpose of controlling a texture goniometer.
In recent years, there has been a tendency toward creating innovative, easy to use and patient-friendly drug delivery systems suitable for every consumer profile, which would ensure safety, stability ...and acceptability of a drug. One of the relatively novel and promising approaches is the manufacture of orodispersible films (ODFs), which is an upcoming area of interest in drug delivery. They are defined as polymer thin films that disintegrate in the oral cavity within seconds, without drinking water or chewing, and eliminate the risk of choking. Gaining special usefulness in therapies of children and the elderly, ODFs seem to fill the gap in the range of preparations available for these groups of patients. As no detailed monography of ODFs including testing methods and uniform requirements has been presented in any of the pharmacopoeias to date, the aim of this article is to give an overview of the applied testing methods, their modifications and innovative approaches related to ODF quality assessment.
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