Injection of a non-Newtonian fluid through one side of a long vertical channel

Summary The problem considered here is the injection of a non-Newtonian fluid with elastic properties through one side of a long vertical channel. Using the transformations proposed by Wang and Skalak [14] for the velocity components, the basic equations governing the flow and heat transfer are reduced to a set of ordinary differential equations. These equations have been solved approximately subject to the relevant boundary conditions. The effect of the non-Newtonian parameter,S, on the velocity field and heat transfer on the walls is examined carefully.     

Flow of an Oldroyd 6-constant fluid between intersecting planes, one of which is moving

Summary The problem dealing with the two-dimensional steady and slow flow of an Oldroyd 6-constant fluid between intersecting planes, one of which is fixed and the other moving, has been analysed. Using truncated series expansions given by Strauss [4] for the stream function and stress components, the governing equations of the problem are reduced to linear ordinary differential equations. These equations have been solved analytically subject to the relevant boundary conditions. The effects of the non-Newtonian parameters on the flow pattern are carefully delineated. There is, unlike the case of Newtonian fluid, a secondary flow near the corner.     

Low-cost optical amplitude modulator based on a tapered single-mode optical fiber

A new, to our knowledge, modulator based on a tapered single-mode optical fiber is introduced. The electro-optic device consists of a tapered optical fiber placed on a resonator made of a piezoelectric material. An electrical signal applied to the piezoelectric material makes the taper bend, and that displacement produces a modulation in the intensity of the optical signal traveling through the fiber. This device is very easy to build and is low in cost. Because of its nature, this new device might be very useful in optical fiber sensors. Its performance is analyzed, and the results are discussed.     

创业国家中心

正创业国家中心(SNC)坐落于特拉维夫市中心,为以色列科技基金会而建。这里原有的六层独立大楼,改造为共用空间、办公室、会议室和展览区。办公区位于两处正式活动空间之间,打造休闲舒适的工作氛围。作为针对科技和计算机领域人员的建筑,设计上追求精确性和实     

Multi-Run Concrete Autoencoder to Identify Prognostic lncRNAs for 12 Cancers

Background: Long non-coding RNA plays a vital role in changing the expression profiles of various target genes that lead to cancer development. Thus, identifying prognostic lncRNAs related to different cancers might help in developing cancer therapy. Method: To discover the critical lncRNAs that can identify the origin of different cancers, we propose the use of the state-of-the-art deep learning algorithm concrete autoencoder (CAE) in an unsupervised setting, which efficiently identifies a subset of the most informative features. However, CAE does not identify reproducible features in different runs due to its stochastic nature. We thus propose a multi-run CAE (mrCAE) to identify a stable set of features to address this issue. The assumption is that a feature appearing in multiple runs carries more meaningful information about the data under consideration. The genome-wide lncRNA expression profiles of 12 different types of cancers, with a total of 4768 samples available in The Cancer Genome Atlas (TCGA), were analyzed to discover the key lncRNAs. The lncRNAs identified by multiple runs of CAE were added to a final list of key lncRNAs that are capable of identifying 12 different cancers. Results: Our results showed that mrCAE performs better in feature selection than single-run CAE, standard autoencoder (AE), and other state-of-the-art feature selection techniques. This study revealed a set of top-ranking 128 lncRNAs that could identify the origin of 12 different cancers with an accuracy of 95%. Survival analysis showed that 76 of 128 lncRNAs have the prognostic capability to differentiate high- and low-risk groups of patients with different cancers. Conclusion: The proposed mrCAE, which selects actual features, outperformed the AE even though it selects the latent or pseudo-features. By selecting actual features instead of pseudo-features, mrCAE can be valuable for precision medicine. The identified prognostic lncRNAs can be further studied to develop therapies for different cancers.     

Enhancing the Production of Light Olefins by Catalytic Cracking of FCC Naphtha over Mesoporous ZSM-5 Catalyst

The enhanced production of light olefins from the catalytic cracking of FCC naphtha was investigated over a mesoporous ZSM-5 (Meso-Z) catalyst. The effects of acidity and pore structure on conversion, yields and selectivity to light olefins were studied in microactivity test (MAT) unit at 600 °C and different catalyst-to-naphtha (C/N) ratios. The catalytic performance of Meso-Z catalyst was compared with three conventional ZSM-5 catalysts having different SiO₂/Al₂O₃ (Si/Al) ratios of 22 (Z-22), 27 (Z-27) and 150 (Z-150). The yields of propylene (16 wt%) and ethylene (10 wt%) were significantly higher for Meso-Z compared with the conventional ZSM-5 catalysts. Almost 90% of the olefins in the FCC naphtha feed were converted to lighter olefins, mostly propylene. The aromatics fraction in cracked naphtha almost doubled in all catalysts indicating some level of aromatization activity. The enhanced production of light olefins for Meso-Z is attributed to its small crystals that suppressed secondary and hydrogen transfer reactions and to its mesopores that offered easier transport and access to active sites.     

Elastic properties of cement-stabilised mixes with steel slag

In this study, we evaluated the elastic and mechanical properties of a new type of cement-stabilised material made with steel slag, varying the content of cement and steel slag. To study the elastic properties of these mixes, we measured their density, compressive strength and ultrasound pulse velocity at curing ages of 7, 28 and 90 days. The aggregate type and curing age greatly affected the elastic properties and varied much depending on the cement content. The Poisson's ratio chosen in analyses had little influence on the dynamic modulus. Various expressions given by building codes were used to predict the elastic properties of the mixtures. These codes generated very different values of the static modulus of elasticity, making most of them unsuitable for predicting the elastic properties of cement-stabilised materials. Using our experimental data, we provide the best combination of existing equations to predict elastic properties, and we conclude that measuring the ultrasound pulse velocity is a suitable way to predict the mechanic and elastic properties of cement-stabilised materials.     

Significance of the rate of systemic change in blood pressure on the short-term autoregulatory response in normotensive and spontaneously hypertensive rats

Cerebral autoregulation, the physiological regulatory mechanism that maintains a constant cerebral blood flow (CBF) over wide ranges of arterial blood pressure, was investigated in normotensive and spontaneously hypertensive rats by means of laser-Doppler flowmetry. Systemic arterial hypertension was produced at rates ranging from 0.02 mm Hg/second to 11 mm Hg/second by constant infusion of epinephrine and norepinephrine. Systemic arterial hypotension was produced at rates ranging from -0.03 mm Hg/second to -12 mm Hg/second, either by bleeding the animals into a reservoir or by compressing the abdomen. In those cases with a low rate of change in systemic arterial blood pressure (SABP), the measurements lasted for 5 +/- 2 minutes, and in those with a high rate of change in SABP, measurements lasted for 40 +/- 30 seconds. The purpose was to record the time of onset and course of autoregulation in the basal ganglia in response to slow or rapid changes in SABP. CBF in the basal gray matter remained at baseline values (i.e., autoregulation was functioning) if the rate of increase of SABP did not exceed a critical value (0.10 mm Hg/second in the normotensive rats; 0.35 mm Hg/second in the spontaneously hypertensive rats). When hypertension was produced at faster rates, CBF followed arterial blood pressure passively, and no autoregulatory response was observed for 2 +/- 1 minutes. Hypotension did not change the baseline CBF when it was not produced at a rate faster than -0.4 mm Hg/second in normotensive rats and -0.15 mm Hg/second in spontaneously hypertensive rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Design of fault tolerant wireless sensor networks satisfying survivability and lifetime requirements

Sensor networks are deployed to accomplish certain specific missions over a period of time. It is essential that the network continues to operate, even if some of its nodes fail. It is also important that the network is able to support the mission for a minimum specified period of time. Hence, the design of a sensor network should not only provide some guarantees that all data from the sensor nodes are gathered at the base station, even in the presence of some faults, but should also allow the network to remain functional for a specified duration. This paper considers a two-tier, hierarchical sensor network architecture, where some relay nodes, provisioned with higher power and other capabilities, are used as cluster heads. Given a distribution of sensor nodes in a sensor network, finding the locations to place a minimum number of relay nodes such that, each sensor node is covered by at least one relay node, is known to be a computationally difficult problem. In addition, for successful and reliable data communication, the relay nodes network needs to be connected, as well as resilient to node failures. In this paper, a novel integrated Integer Linear Program (ILP) formulation is proposed, which, unlike existing techniques, not only finds a suitable placement strategy for the relay nodes, but also assigns the sensor nodes to the clusters and determines a load-balanced routing scheme. Therefore, in addition to the desired levels of fault tolerance for both the sensor nodes and the relay nodes, the proposed approach also meets specified performance guarantees with respect to network lifetime by limiting the maximum energy consumption of the relay nodes.