Dual Band PIFA MIMO Antenna Design with High Isolation for Mobile and Wireless Applications by Using the Genetics Algorithms and Non-uniform Overlapping Method

Wireless Personal Communications - Due to the development and growth of Internet platforms and web services as communication resources, the competition for the network and its limited resources is...     

柏林2002年UIA世界建筑大会

怎样报导一个在柏林有五天会议和80场附加展览,以及全德国的7次预备会议好呢?在4000多名代表中,58%不是德国人,其中最大的代表团是来自巴西、中国、法国、希腊和俄国的,非洲和印度没有出席.为什么这样呢?     

Photoinduced dark reactions of some cationic dyes

The poor lightfastness of many cationic dyes restricts the range of application which their otherwise attractive spectral properties would predict. Fading mechanisms are varied and complex. The present preliminary account of the photolysis of aerated cyclohexanone solutions of malachite Green, Rosaniline or Rhodamine B for relatively short periods (up to 120 seconds) followed by a longer-term (up to 60 minutes) photoinduced dark bleaching reaction presents a further complication. Some mechanistic possibilities are suggested.     

A new nanostructured material based on fluorophosphate incorporated into a zinc–aluminium layered double hydroxide by ion exchange

Layered double hydroxides (LDHs), also called anionic clays, consist of cationic brucite-like layers and exchangeable interlayer anions. These hydrotalcite-like compounds, with Zn and Al in the layers and chloride in the interlayer space, were prepared following the coprecipitation method at constant pH. The effect of pH, aging time and anion concentration on the intercalation of fluorophosphate \((\hbox {PO}_{3}\hbox {F}^{2-}\), FP) in the [Zn–Al] LDH was investigated. The best crystalline material, with high exchange extent, was obtained by carrying out the exchange at 25\({^{\circ }}\hbox {C}\) in a 0.03 M FP solution at pH 7 with at least 42 h of aging time. A mechanism for the FP intercalation was confirmed by X-ray diffraction, infrared spectroscopy and thermogravimetry (TG) analyses (TG and DTG curves).     

Blood Clots versus PRF: Activating TGF-β Signaling and Inhibiting Inflammation In Vitro

The preparation of platelet-rich fibrin (PRF) requires blood centrifugation to separate the yellow plasma from the red erythrocyte fraction. PRF membranes prepared from coagulated yellow plasma are then transferred to the defect sites to support tissue regeneration. During natural wound healing, however, it is the unfractionated blood clot (UBC) that fills the defect site. It is unclear whether centrifugation is necessary to prepare a blood-derived matrix that supports tissue regeneration. The aim of the present study was to compare lysates prepared from PRF and UBC based on bioassays and degradation of the respective membranes. We report here that lysates prepared from PRF and UBC membranes similarly activate TGF-β signaling, as indicated by the expression of interleukin 11 (IL-11), NADPH oxidase 4 (NOX-4) and proteoglycan 4 (PRG4) in gingival fibroblasts. Consistently, PRF and UBC lysates stimulated the phosphorylation and nuclear translocation of Smad3 in gingival fibroblasts. We further observed that PRF and UBC lysates have comparable anti-inflammatory activity, as shown by the reduction in lipopolysaccharide (LPS)-induced IL-6, inducible nitric oxidase synthase (iNOS) and cyclooxygenase 2 (COX-2) expression in RAW264.7 cells. Moreover, inflammation induced by Poly (1:C) HMW and FSL-1, which are agonists of Toll-like receptor (TLR) 3 and 2/6, respectively, was reduced by both PRF and UBC. PRF and UBC lysates reduced the nuclear translocation of p65 in LPS-induced RAW264.7 cells. In contrast to the similar activity observed in the bioassays, UBC membranes lack the structural integrity of PRF membranes, as indicated by the rapid and spontaneous disintegration of UBC membranes. We show here that the lysates prepared from PRF and UBC possess robust TGF-β and anti-inflammatory activity. However, visual inspection of the PRF and UBC membranes confirmed the negative impact of erythrocytes on the structural integrity of membranes prepared from whole blood. The data from the present study suggest that although both UBC and PRF have potent TGF-β and anti-inflammatory activity, UBC does not have the strength properties required to be used clinically to prepare applicable membranes. Thus, centrifugation is necessary to generate durable and clinically applicable blood-derived membranes.     

Novel design of a triple band PIFA antenna by using a binary genetic algorithm

Journal of Computational Electronics - In this study, we propose a miniature triple band PIFA antenna (planar inverted-F antenna) composed of uniform semi-patches for LTE2600/WLAN/WIMAX/HIPERLAN-2...     

Beam-Steerable Ultra-Wide-Band Miniaturized Elliptical Phased Array Antenna Using Inverted-L-Shaped Modified Inset Feed and Defected Ground Structure for 5G Smartphones Millimeter-Wave Applications

Multi Input Multi Output (MIMO) and phased array systems are considered a key technologies to realize the 5G communication systems. Therefore, the purpose of this research is the suggestion of a novel mm-wave Ultrawide Band (UWB) antenna design with compact and straightforward layout suitable for both MIMO and phased array systems. Hence, the designed antenna array has been studied separately as a MIMO antenna and as a phased array antenna to carefully assess the performance of each system. The single antenna design is an elliptical patch antenna where the design novelty lies in the combination of a modified inset-feed and defected ground structure to provide a large bandwidth without any compromise in the radiation performance, nor in antenna size and design simplicity. The Design process are performed using CST MWS software, where the Rogers RT/Duroid 5880 substrate is chosen to construct the antenna. A broadband characteristic of 8.7 GHz from 26 to 34.7 GHz with two resonant frequencies at 28 GHz and 33 GHz is obtained. A good radiation properties are achieved, where the gain is greater than 4.5 dB while the radiation efficiency exceeds 97% over the operating band. The MIMO and phased array antennas are made up of 12-elements of the single UWB-antenna arranged linearly along the width-edge of the smartphone mainboard. The MIMO antenna proves a high diversity performance in terms of Diversity Gain (DG), Envelope Correlation Coefficient (ECC), Total Active Reflection Coefficient (TARC), Channel Capacity Loss (CCL) and Mean Effective Gain (MEG), owing to the low mutual coupling less than ??20 dB, which is obtained using a separating slits between the elements. In addition, the suggested phased array provides a highly stable gain up to 15 dB over the entire bandwidth at broadside direction, besides the wide scanning range of?±?60° at 28 GHz and?±?40° at 33 GHz. Hence, the attained results assure that the suggested antenna could be appropriate for incorporation in 5G smartphones and other wireless devices and can be effectively used for both phased array and MIMO applications.

     

Reliability and validity of the Home Care STAT (Safety Task Assessment Tool)

Home care workers are a priority population for ergonomic assessment and intervention, but research on caregivers' exposures to hazards is limited. The current project evaluated the reliability and validity of an ergonomic self-assessment tool called Home Care STAT (Safety Task Assessment Tool). Participants (N = 23) completed a background survey followed by 10–14 days of self-monitoring with the STAT. Results showed that the most frequent task was house cleaning, and that participants regularly performed dangerous manual client moving and transferring tasks. Researcher in-home observations of 14 workers (duration ≤2 h) demonstrated that workers' self-assessments were moderately reliable. Correlational and multi-level analyses of daily self-assessment data revealed that several task exposures were significantly related to daily fatigue and/or pain. Other associations have implications for Total Worker Health™; for example, daily stress was positively associated with both pain and consumption of high calorie snacks. Findings support the STAT as a reliable and potentially valid tool for measuring home care workers' exposures to physically demanding tasks.