287 research outputs found

    Out-of-plane Characterization of Silicon-on-insulator Multiuser MEMS Processes-based Tri-axis Accelerometer

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    In this paper, we discuss the analysis of out-of-plane characterization of a capacitive tri-axis accelerometer fabricated using SOI MUMPS (Silicon-on Insulator Multi user MEMS Processes) process flow and the results are compared with simulated results. The device is designed with wide operational 3 dB bandwidth suitable for measuring vibrations in industrial applications. The wide operating range is obtained by optimizing serpentine flexures at the four corners of the proof mass. The accelerometer structure was simulated using COMSOL Multiphysics and the displacement sensitivity was observed as 1.2978 nm/g along z-axis. The simulated resonant frequency of the device was found to be 13 kHz along z axis. The dynamic characterization of the fabricated tri-axis accelerometer produces the out-of-plane vibration mode frequency as 13 kHz which is same as the simulated result obtained in z-axis

    Visualization and Control of the Conveyer by PAC Rockwell

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    katedra: MTI; přílohy: 1xCD; rozsah: 91 s.Diplomová práce se zabývá řízením a vizualizací modelu dopravníku, který plní funkci třídicí linky. Model dopravníku dokáže třídit válečky, jejichž rozdíl výšky je v řádech setin milimetru. Řízení je zajištěno programovatelným automatem 1756-L63 od společnosti Allen-Bradley. Úkolem práce je vytvořit software ve vývojovém prostředí RSLogix, který bude plnit výše popsanou funkci, a navrhnout vizualizaci tohoto procesu v prostředí RSView. V práci jsou nejprve popsány dílčí části potřebné pro zapojení a oživení modelu dopravníku. Druhá část je zaměřena na softwarovou realizaci programu a vizualizaci procesu ve výše uvedených vývojových prostředích. Poslední část je věnována úloze do výuky.This diploma thesis deals with control and visualization of the conveyor model which performs the function of the sorting line. The conveyor model is able to sort rollers whose height difference is in the order of hundredths of millimeters. The control is provided by programmable machine 1756-L63 from Allen-Bradley company. The task of the diploma thesis is to create software in the RSLogix developmental environment, which will fulfill the function described above and the visualization design of the process in RSView environment. The partial parts required for connection and recovery of the conveyor model are described at first in the work. The second part is focused on the software implementation of the program and the visualization of the process in development environments mentioned above. The last part is devoted to the teaching assignment

    Visualization and Control of the Conveyer by PAC Rockwell

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    Drive of piezoelectric motor

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    Drive of piezoelectric motor

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    katedra: MTI; rozsah: 74 s.,z toho 16 s. obr. přílohBakalářská práce se zabývá realizací dvou přípravků a odzkoušením jejich funkčnosti. Jedním z těchto přípravků je DC/DC měnič z 12 V na 140 V pracující v režimu Flyback. Druhým zařízením je univerzální výkonový člen, který je proveden přes čtyři nezávislé půlmůstky. Tento budič bude používat PWM sinusovou modulaci. V práci jsou nejprve popsány dílčí části potřebné pro realizaci přípravků. Druhá část je zaměřena na oživení a odzkoušení výrobků.Bachelor thesis is engaged in implementation of two preparations and examining of their functionality. One of them is DC/DC from 12V to 140V converter, working in Flyback mode. The other appliance is an universal power item, which is carried out by four independent half bridges. This exciter is based on PWM sine modulation. Partial components are described in this thesis at first, the other part is focused on activate and examining of products

    Shear stress-induced angiogenesis in mouse muscle is independent of the vasodilator mechanism and quickly reversible.

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    Aim: Is modulation of skeletal muscle capillary supply by altering blood flow due to a presumptive shear stress response per se, or dependent on the vasodilator mechanism? Methods: The response to four different vasodilators, and cotreatment with blockers of NO and prostaglandin synthesis, was compared. Femoral artery blood flow was correlated with capillary-to-fibre ratio (C:F) and protein levels of putative angiogenic compounds. Results: All vasodilators induced a similar increase in blood flow after 14 days, with a similar effect on C:F (1.62 ± 0.05, 1.60 ± 0.01, 1.57 ± 0.06, 1.57 ± 0.07, respectively, all P < 0.05 vs. control 1.20 ± 0.01). Concomitant inhibitors revealed differential effects on blood flow and angiogenesis, demonstrating that a similar response may have different signalling origins. The time course of this response with the most commonly used vasodilator, prazosin, showed that blood flow increased from 0.40 mL min−1 to 0.61 mL min−1 by 28 days (P < 0.05), dropped within 1 week after the cessation of treatment (0.54 mL min−1; P < 0.05) and returned to control levels by 6 weeks. In parallel with FBF, capillary rarefaction began within 1 week (P < 0.05), giving C:F values similar to control by 2 weeks. Of the dominant signalling pathways, prazosin decreased muscle VEGF, but increased its cognate receptor Flk-1 (both P < 0.01); levels of eNOS varied with blood flow (P < 0.05), and Ang-1 initially increased, while its receptor Tie-2 was unchanged, with only modest changes in the antiangiogenic factor TSP-1. Conclusion: Hyperaemia-induced angiogenesis, likely in response to elevated shear stress, is independent of the vasodilator involved, with a rapid induction and quick regression following the stimulus withdrawal

    A Perspective Around Cephalopods and Their Parasites, and Suggestions on How to Increase Knowledge in the Field

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    Although interest in several areas of cephalopod research has emerged over the last decades (e.g., neurobiology, aquaculture, genetics, and welfare), especially following their 2010 inclusion in the EU Directive on the use of animals for experimental purposes, knowledge regarding the parasites of cephalopods is lacking. Cephalopods can be intermediate, paratenic, or definitive hosts to a range of parasites with a wide variety of life cycle strategies. Here, we briefly review the current knowledge in cephalopod parasitological research, summarizing the main parasite groups that affect these animals. We also emphasize some topics that, in our view, should be addressed in future research, including: (i) better understanding of life cycles and transmission pathways of common cephalopod parasites; (ii) improve knowledge of all phases of the life cycle (i.e., paralarvae, juveniles, adults and senescent animals) and on species from polar deep sea regions; (iii) exploration of the potential of using cephalopod-parasite specificity to assess population boundaries of both, hosts and parasites; (iv) risk evaluation of the potential of standard aquacultural practices to result in parasite outbreaks; (v) evaluation and description of the physiological and behavioral effects of parasites on their cephalopod hosts; (vi) standardization of the methods for accurate parasite sampling and identification; (vii) implementation of the latest molecular methods to facilitate and enable research in above mentioned areas; (viii) sharing of information and samples among researchers and aquaculturists. In our view, addressing these topics would allow us to better understand complex host-parasite interactions, yield insights into cephalopod life history, and help improve the rearing and welfare of these animals in captivity

    Effect of ascorbate on plasminogen activator inhibitor-1 expression and release from platelets and endothelial cells in an in-vitro model of sepsis.

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    The microcirculation during sepsis fails due to capillary plugging involving microthrombosis. We demonstrated that intravenous injection of ascorbate reduces this plugging, but the mechanism of this beneficial effect remains unclear. We hypothesize that ascorbate inhibits the release of the antifibrinolytic plasminogen activator inhibitor-1 (PAI-1) from endothelial cells and platelets during sepsis. Microvascular endothelial cells and platelets were isolated from mice. Cells were cultured and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNFα), or thrombin (agents of sepsis), with/without ascorbate for 1-24 h. PAI-1 mRNA was determined by quantitative PCR. PAI-1 protein release into the culture medium was measured by ELISA. In platelets, PAI-1 release was measured after LPS, TNFα, or thrombin stimulation, with/without ascorbate. In endothelial cells, LPS and TNFα increased PAI-1 mRNA after 6-24 h, but no increase in PAI-1 release was observed; ascorbate did not affect these responses. In platelets, thrombin, but not LPS or TNFα, increased PAI-1 release; ascorbate inhibited this increase at low extracellular pH. In unstimulated endothelial cells and platelets, PAI-1 is released into the extracellular space. Thrombin increases this release from platelets; ascorbate inhibits it pH-dependently. The data suggest that ascorbate promotes fibrinolysis in the microvasculature under acidotic conditions in sepsis
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