136 research outputs found
Self-Cleaning Micro-Windows for In-Tailpipe Optical Exhaust Gas Measurements
Exhaust gas measurement in the harsh environment of the tailpipe of a combustion engine by optical techniques is a highly robust technique, provided that optical access is maintained in the presence of particulate matter (PM). The considerations are presented for the systematic design of membranes with integrated heaters in SiC-on-Si technology for generating a well-defined lateral temperature profile with peak temperatures above 600 \ub0C. Periodically raising the temperature of the membranes to such a level is demonstrated to keep the surface transparent by oxidation of soot deposits. This paper is about continuous heating of the membrane to a temperature slightly higher than that of the exhaust gas. At such temperatures thermophoretic repulsion of PM allows allows long-term optical measurement in the exhaust without the thermo-mechanical loading by repetitive thermal cycling
Finger Number and Device Performance: A Case Study of Reduced Graphene Oxide Microsupercapacitors
Microsupercapacitors (MSCs) are recognized as suitable energy storage devices for the internet of things (IoTs) applications. Herein is described the work conducted to assess the areal energy and power densities of MSCs with 2, 10, 20, and 40 interdigital finger electrodes on a fixed device footprint area (the finger interspacing is fixed at 40 ΞΌm, and the finger width and length are allowed to vary to fit the footprint area). The MSCs are based on reduced graphene oxide (rGO) materials and fabricated with a spin-coating and etch method. The performance evaluation indicates a strong dependency of areal capacitance and energy density on the number of fingers, and the maximum (impedance match) power density is also influenced to a relatively large extent, whereas the average power density is not sensitive to the configuration parameters in the present evaluation settings (scan rate 20β200 mV sβ1 and current density of 100 ΞΌA cmβ2). For the rGO-based devices, the equivalent distributed resistance may play an important role in determining the device resistance and power-related performance
Maintaining transparency of a heated MEMs membrane for enabling long-term optical measurements on soot-containing exhaust gas
Ensuring optical transparency over a wide spectral range of a window with a view into the tailpipe of the combustion engine, while it is exposed to the harsh environment of sootcontaining exhaust gas, is an essential pre-requisite for introducing optical techniques for long-term monitoring of automotive emissions. Therefore, a regenerable window composed of an optically transparent polysilicon-carbide membrane with a diameter ranging from 100 \ub5m up to 2000 \ub5m has been fabricated in microelectromechanical systems (MEMS) technology. In the first operating mode, window transparency is periodically restored by pulsed heating of the membrane using an integrated resistor for heating to temperatures that result in oxidation of deposited soot (600β700 \ub0C). In the second mode, the membrane is kept transparent by repelling soot particles using thermophoresis. The same integrated resistor is used to yield a temperature gradient by continuous moderate-temperature heating. Realized devices have been subjected to laboratory soot exposure experiments. Membrane temperatures exceeding 500 \ub0C have been achieved without damage to the membrane. Moreover, heating of membranes to ΞT = 40 \ub0C above gas temperature provides sufficient thermophoretic repulsion to prevent particle deposition and maintain transparency at high soot exposure, while non-heated identical membranes on the same die and at the same exposure are heavily contaminated
Investigation of palladium current collectors for vertical graphene-based microsupercapacitors
As microsystems are reduced in size and become integrated in the Internet of Things (IoT), they require an adequate power supply which can be integrated at the same size scale. Microsupercapacitors (MSCs), if coupled with on-chip harvesters, can offer solutions for a self-sustaining, on-chip power supply. However, the implementation of reliable MSC wafer-scale production compatible with CMOS technology remains a challenge. Palladium (Pd) is known as a CMOS compatible metal and, in this paper, we investigate the use of Pd as a contact material for vertical graphene (VG) electrodes in wafer-scale MSC fabrication. We show that a Ti diffusion barrier is required to prevent short-circuiting for the successful employment of Pd contacts. The fabricated MSCs demonstrate a capacitance of 1.3 ΞΌF/cm2 with an energy density of 0.42 ΞΌJ/cm2. Thus, utilization of a Ti diffusion barrier with a CMOS compatible Pd metal electrode is a step towards integrating MSCs in semiconductor microsystems
Π‘ΠΊΠ»Π°Π΄ΠΎΠ²Ρ ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΈ ΠΌΠΎΠ²Π½ΠΎΡ ΠΎΡΠΎΠ±ΠΈΡΡΠΎΡΡΡ Π² ΠΊΠΎΠ½ΡΠ΅ΠΊΡΡΡ ΠΌΡΠΆΠΊΡΠ»ΡΡΡΡΠ½ΠΎΡ ΠΊΠΎΠΌΡΠ½ΡΠΊΠ°ΡΡΡ
Π‘ΡΠ°ΡΡΡ ΠΏΡΠΈΡΠ²ΡΡΠ΅Π½Π° Π°Π½Π°Π»ΡΠ·Ρ ΡΠΊΠ»Π°Π΄ΠΎΠ²ΠΈΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΡΠ² ΠΌΠΎΠ²Π½ΠΎΡ ΠΎΡΠΎΠ±ΠΈΡΡΠΎΡΡΡ Π² ΠΊΠΎΠ½ΡΠ΅ΠΊΡΡΡ ΠΌΡΠΆΠΊΡΠ»ΡΡΡΡΠ½ΠΎΡ ΠΊΠΎΠΌΡΠ½ΡΠΊΠ°ΡΡΡ, ΡΡ
Π²Π·Π°ΡΠΌΠΎΠ΄ΡΡ ΡΠ° ΡΡΠ½ΠΊΡΡΠΎΠ½ΡΠ²Π°Π½Π½Ρ Π· ΡΠΎΡΠΊΠΈ Π·ΠΎΡΡ ΠΏΡΠ°Π³ΠΌΠ°ΡΠΈΡΠ½ΠΎΡ ΡΠΏΡΡΠΌΠΎΠ²Π°Π½ΠΎΡΡΡ ΠΌΠΎΠ²Π»Π΅Π½Π½ΡΠ²ΠΎΠ³ΠΎ Π²ΠΏΠ»ΠΈΠ²Ρ. ΠΠ΅ΡΠ°Π»ΡΠ½ΠΎ ΡΠΎΠ·Π³Π»ΡΠ΄Π°ΡΡΡΡΡ ΡΡΠΈ ΡΡΠ²Π½Ρ ΡΡΡΡΠΊΡΡΡΠΈ ΠΌΠΎΠ²Π½ΠΎΡ ΠΎΡΠΎΠ±ΠΈΡΡΠΎΡΡΡ (ΡΡΡΡΠΊΡΡΡΠ½ΠΎ-ΠΌΠΎΠ²Π½ΠΈΠΉ, Π»ΡΠ½Π³Π²ΠΎΠΊΠΎΠ³Π½ΡΡΠΈΠ²Π½ΠΈΠΉ ΡΡ ΠΌΠΎΡΠΈΠ²Π°ΡΡΠΉΠ½ΠΈΠΉ) ΡΠ· Π²ΠΈΠ·Π½Π°ΡΠ΅Π½Π½ΡΠΌ ΡΠΏΠ΅ΡΠΈΡΡΠΊΠΈ ΡΡ
Π½ΡΡ
ΡΠΊΠ»Π°Π΄ΠΎΠ²ΠΈΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΡΠ².Π‘ΡΠ°ΡΡΡ ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° Π°Π½Π°Π»ΠΈΠ·Ρ ΡΠΎΡΡΠ°Π²Π»ΡΡΡΠΈΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ² ΡΠ·ΡΠΊΠΎΠ²ΠΎΠΉ Π»ΠΈΡΠ½ΠΎΡΡΠΈ Π² ΠΊΠΎΠ½ΡΠ΅ΠΊΡΡΠ΅ ΠΌΠ΅ΠΆΠΊΡΠ»ΡΡΡΡΠ½ΠΎΠΉ ΠΊΠΎΠΌΠΌΡΠ½ΠΈΠΊΠ°ΡΠΈΠΉ, ΠΈΡ
Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΡ ΠΈ ΡΡΠ½ΠΊΡΠΈΠΎΠ½ΠΈΡΠΎΠ²Π°Π½ΠΈΡ Ρ ΡΠΎΡΠΊΠΈ Π·ΡΠ΅Π½ΠΈΡ ΠΏΡΠ°Π³ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½Π½ΠΎΡΡΠΈ ΡΠ΅ΡΠ΅Π²ΠΎΠ³ΠΎ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ. ΠΠ΅ΡΠ°Π»ΡΠ½ΠΎ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°ΡΡΡΡ ΡΡΠΈ ΡΡΠΎΠ²Π½Ρ ΡΡΡΡΠΊΡΡΡΡ ΡΠ·ΡΠΊΠΎΠ²ΠΎΠΉ Π»ΠΈΡΠ½ΠΎΡΡΠΈ (ΡΡΡΡΠΊΡΡΡΠ½ΠΎ-ΡΠ·ΡΠΊΠΎΠ²ΠΎΠΉ, Π»ΠΈΠ½Π³Π²ΠΎΠΊΠΎΠ³Π½ΠΈΡΠΈΠ²Π½ΡΠΉ ΠΈ ΠΌΠΎΡΠΈΠ²Π°ΡΠΈΠΎΠ½Π½ΡΠΉ) Ρ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠΈΠΌ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ΠΌ ΡΠΏΠ΅ΡΠΈΡΠΈΠΊΠΈ ΠΈΡ
ΡΠΎΡΡΠ°Π²Π»ΡΡΡΠΈΡ
ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½ΡΠΎΠ².The article is dedicated to the linguistic personality constituent components' analysis in terms of cross-cultural communication, their interaction and functioning with the speech influence pragmatic orientation taken into consideration. The three levels of the linguistic personality (that is, structural linguistic, lingo cognitive and motivation ones) are under analysis with the following their constituent components specificity determinatio
The Expression of BAFF, APRIL and TWEAK Is Altered in Eczema Skin but Not in the Circulation of Atopic and Seborrheic Eczema Patients
The TNF family cytokines BAFF (B-cell activating factor of the TNF family) and APRIL (a proliferation-inducing ligand) are crucial survival factors for B-cell development and activation. B-cell directed treatments have been shown to improve atopic eczema (AE), suggesting the involvement of these cytokines in the pathogenesis of AE. We therefore analyzed the expression of these TNF cytokines in AE, seborrheic eczema (SE) and healthy controls (HC). The serum/plasma concentration of BAFF, APRIL and a close TNF member TWEAK (TNF-like weak inducer of apoptosis) was measured by ELISA. The expression of these cytokines and their receptors in skin was analyzed by quantitative RT-PCR and immunofluorescence. Unlike other inflammatory diseases including autoimmune diseases and asthma, the circulating levels of BAFF, APRIL and TWEAK were not elevated in AE or SE patients compared with HCs and did not correlate with the disease severity or systemic IgE levels in AE patients. Interestingly, we found that the expression of these cytokines and their receptors was altered in positive atopy patch test reactions in AE patients (APT-AE) and in lesional skin of AE and SE patients. The expression of APRIL was decreased and the expression of BAFF was increased in eczema skin of AE and SE, which could contribute to a reduced negative regulatory input on B-cells. This was found to be more pronounced in APT-AE, the initiating acute stage of AE, which may result in dysregulation of over-activated B-cells. Furthermore, the expression levels of TWEAK and its receptor positively correlated to each other in SE lesions, but inversely correlated in AE lesions. These results shed light on potential pathogenic roles of these TNF factors in AE and SE, and pinpoint a potential of tailored treatments towards these factors in AE and SE
Perceptual Rivalry: Reflexes Reveal the Gradual Nature of Visual Awareness
Rivalry is a common tool to probe visual awareness: a constant physical stimulus evokes multiple, distinct perceptual interpretations (βperceptsβ) that alternate over time. Percepts are typically described as mutually exclusive, suggesting that a discrete (all-or-none) process underlies changes in visual awareness. Here we follow two strategies to address whether rivalry is an all-or-none process: first, we introduce two reflexes as objective measures of rivalry, pupil dilation and optokinetic nystagmus (OKN); second, we use a continuous input device (analog joystick) to allow observers a gradual subjective report. We find that the βreflexesβ reflect the percept rather than the physical stimulus. Both reflexes show a gradual dependence on the time relative to perceptual transitions. Similarly, observers' joystick deflections, which are highly correlated with the reflex measures, indicate gradual transitions. Physically simulating wave-like transitions between percepts suggest piece-meal rivalry (i.e., different regions of space belonging to distinct percepts) as one possible explanation for the gradual transitions. Furthermore, the reflexes show that dominance durations depend on whether or not the percept is actively reported. In addition, reflexes respond to transitions with shorter latencies than the subjective report and show an abundance of short dominance durations. This failure to report fast changes in dominance may result from limited access of introspection to rivalry dynamics. In sum, reflexes reveal that rivalry is a gradual process, rivalry's dynamics is modulated by the required action (response mode), and that rapid transitions in perceptual dominance can slip away from awareness
GM-CSF drives dysregulated hematopoietic stem cell activity and pathogenic extramedullary myelopoiesis in experimental spondyloarthritis
Dysregulated hematopoiesis occurs in several chronic inflammatory diseases, but it remains unclear how hematopoietic stem cells (HSCs) in the bone marrow (BM) sense peripheral inflammation and contribute to tissue damage in arthritis. Here, we show the HSC gene expression program is biased toward myelopoiesis and differentiation skewed toward granulocyte-monocyte progenitors (GMP) during joint and intestinal inflammation in experimental spondyloarthritis (SpA). GM-CSF-receptor is increased on HSCs and multipotent progenitors, favoring a striking increase in myelopoiesis at the earliest hematopoietic stages. GMP accumulate in the BM in SpA and, unexpectedly, at extramedullary sites: in the inflamed joints and spleen. Furthermore, we show that GM-CSF promotes extramedullary myelopoiesis, tissue-toxic neutrophil accumulation in target organs, and GM-CSF prophylactic or therapeutic blockade substantially decreases SpA severity. Surprisingly, besides CD4+ T cells and innate lymphoid cells, mast cells are a source of GM-CSF in this model, and its pathogenic production is promoted by the alarmin IL-33
Caspase-2 Mediated Apoptotic and Necrotic Murine Macrophage Cell Death Induced by Rough Brucella abortus
Brucella species are Gram-negative, facultative intracellular bacteria that cause zoonotic brucellosis. Survival and replication inside macrophages is critical for establishment of chronic Brucella infection. Virulent smooth B. abortus strain 2308 inhibits programmed macrophage cell death and replicates inside macrophages. Cattle B. abortus vaccine strain RB51 is an attenuated rough, lipopolysaccharide O antigen-deficient mutant derived from smooth strain 2308. B. abortus rough mutant RA1 contains a single wboA gene mutation in strain 2308. Our studies demonstrated that live RB51 and RA1, but not strain 2308 or heat-killed Brucella, induced both apoptotic and necrotic cell death in murine RAW264.7 macrophages and bone marrow derived macrophages. The same phenomenon was also observed in primary mouse peritoneal macrophages from mice immunized intraperitoneally with vaccine strain RB51 using the same dose as regularly performed in protection studies. Programmed macrophage cell death induced by RB51 and RA1 was inhibited by a caspase-2 inhibitor (Z-VDVAD-FMK). Caspase-2 enzyme activation and cleavage were observed at the early infection stage in macrophages infected with RB51 and RA1 but not strain 2308. The inhibition of macrophage cell death promoted the survival of rough Brucella cells inside macrophages. The critical role of caspase-2 in mediating rough B. abortus induced macrophage cell death was confirmed using caspase-2 specific shRNA. The mitochondrial apoptosis pathway was activated in macrophages infected with rough B. abortus as demonstrated by increase in mitochondrial membrane permeability and the release of cytochrome c to cytoplasm in macrophages infected with rough Brucella. These results demonstrate that rough B. abortus strains RB51 and RA1 induce apoptotic and necrotic murine macrophage cell death that is mediated by caspase-2. The biological relevance of Brucella O antigen and caspase-2-mediated macrophage cell death in Brucella pathogenesis and protective Brucella immunity is discussed
CMOS Compatible Fabrication of Mid Infrared Microspectrometers Based on an Array of Metamaterial Absorbers
The design of a mid-infrared micro-spectrometer based on an array of differently tuned narrow-band metamaterial absorbers is presented. The spectral response is tailored by the design of the unit cell. Each spectral band is composed of a thermopile detector with a 300
7180 ΞΌm2 Al-based metamaterial absorber fabricated in a CMOS compatible post-process. The challenges in the fabrication of the sub-ΞΌm features within the unit cell over a several mm2 absorber area by equipment that is part of the standard infrastructure of a MEMS facility is addressed. The design and fabrication method utilized here for the first time enables the CMOS fabrication of integrated large-area plasmonic components on thermal detectors
- β¦