Application of dynamic pressure probe technique to characterize a circulating fluidized bed

In this study a small diameter dynamic pressure probe was used to measure the flow characteristics and the annulus thickness in a circulating fluidized bed. The nonhomogeities of fluidization in the vertical and radial directions have been measured and the results are presented in a new way, as dynamic pressure against time. The diagrams reveal that the flow can, under certain conditions, exhibit significant reversals in the core areas. Particle size distribution in the vertical direction was also studied by using the quick-closing valve technique. The pilot scale riser was cylindrical and the particles were typical FCC catalyst.     

An advanced detrending method with application to HRV analysis

An advanced, simple to use, detrending method to be used before heart rate variability analysis (HRV) is presented. The method is based on smoothness priors approach and operates like a time-varying finite-impulse response high-pass filter. The effect of the detrending on time- and frequency-domain analysis of HRV is studied.     

Acetylation enhances the tabletting properties of starch

The aim of this study was the evaluation of starch acetate (SA) powders used as tablet excipients. Deformation during powder volume reduction, strain-rate sensitivity, intrinsic elasticity of the materials, and tensile strength of the tablets were examined. Results showed that SA with the lowest degree of substitution (ds) still possessed characteristics of native starch granules. Due to dissolution in synthesis, the properties of higher ds SAs depended on precipitation and drying processes. The acetate moiety, perhaps in combination with existing hydroxyl groups, was a very effective bond-forming substituent. The formation of strong molecular bonds increased, leading to a very firm and intact tablet structure. Small changes existed in compression-induced deformation due to acetylation. Some fragmentation was induced due to the slightly harder and more irregular shape of high-substituted SA particles. The plastic flow under compression was enhanced. Acetylated material was slightly less sensitive to fast elastic recovery in-die, but somewhat more elastic out-of-die. In spite of their superior bonding, SAs under compression behaved similarly to native starches. It was concluded that deformation properties were more the consequence of the molecular chain structure properties of the starch polymer than the effect of the acetate moiety itself. In contrast, the opposite seemed to be the case with the extensive improvement in bond-forming properties.     

Release of chlorhexidine digluconate and flexural properties of glass fibre reinforced provisional fixed partial denture polymer

The objective of this study was to determine the flexural properties and the release of chlorhexidine digluconate (CHX) of CHX laced unidirectional E-glass fibre reinforced provisional fixed partial denture polymer. Bar shaped test specimens (3.3 × 10.0 × 65.0 mm) were fabricated from provisional fixed partial denture polymer (mixture of poly[ethylmethacrylate] powder and n-poly[butyl methacrylate] monomer liquid) with E-glass fibre reinforcements. Poly(methyl methacrylate) preimpregnated continuous unidirectional glass fibre reinforcement was laced with CHX. The glass fibre reinforcements were incorporated into the polymer and the polymerised to the form of test specimens. In addition test specimens without CHX in glass fibre reinforcement were made for comparison. Control specimens did not contain glass fibres in the test specimens. Flexural strength and modulus of test specimens (n = 6) was tested with three-point bending test after storing the specimens dry or in water (two weeks). Released CHX was determined with high performance liquid chromatography during 180 days water immersion. In dry conditions, the flexural strength and the modulus of the polymer was 43 MPa and 1.7 GPa, and with glass fibre reinforcement 96 MPa and 3.5 GPa. With the reinforcement laced with CHX, the strength was 92 MPa and the modulus was 3.2 GPa. The water storage of test specimens did not weaken the reinforced polymer. The majority of the CHX released from the glass fibre reinforced polymer during the first days of storage in water. Flexural properties of provisional fixed partial denture polymer were increased using glass fibre reinforcement. The fibre reinforcement that was laced with CHX resulted in similar reinforcing effect.     

Use of potassium formate in road winter deicing can reduce groundwater deterioration

We present here an aquifer scale study on the fate of potassium formate, an alternative, weakly corrosive deicing agent in soil and subsurfaces. Potassium formate was used to deice a stretch of a highway in Finland. The fate of the formate was examined by monitoring the groundwater chemistry in the underlying aquifer of which a conceptual model was constructed. In addition, we determined aerobic and anaerobic biodegradation rates of formate at low temperatures (-2 to +6 degrees C) in soil microcosms. Our results show that the formate did not enter the saturated zone through the thin vadose zone; thus, no undesirable changes in the groundwater chemistry were observed. Furthermore, the conceptual model explained the distribution of chloride in the aquifer used in deicing for the past 30 years. We recorded mineralization potential up to 97% and up to 17% within 24 h under aerobic and anaerobic conditions, respectively, in the soil and subsurface samples obtained from the site. This demonstrates that biodegradation in the topsoil layers was responsible for the removal of the formate. We conclude that the use of potassium formate can potentially help diminish the negative impacts of road winter deicing on groundwater without jeopardizing traffic safety.     

Pn Photodiodes for Pulsed Laser Rangefinding Applications Realized in Standard CMOS/BiCMOS Processes

This paper describes simulation of theoperation of integrated high-speed photodiodes and verification of the results bymeans of measurements performed with two typesof photodiode, one implemented in a standard 0.8m CMOS process and the other in a standard1.2 m BiCMOS process. The measured rise timesand responsivities of the photodiodes were <5ns and 0.28 A/W in the CMOS process and 30 ns and0.31 A/W in the BiCMOS process. Furthermore, thesuitability of the photodiode for 3D vision wasinvestigated by designing an array ofphotodetectors and measuring the isolationbetween the detector blocks. The results confirmthat the photodetectors and receiver for a pulsedlaser rangefinder can be implemented on the samechip in a standard process without any processmodifications.     

Polygonal approximation of closed discrete curves

Optimal polygonal approximation of closed curves differs from the case of open curve in the sense that the location of the starting point must also be determined. Straightforward exhaustive search would take N times more time than the corresponding optimal algorithm for an open curve, because there are N possible points to be considered as the starting point. Faster sub-optimal solution can be found by iterating the search and heuristically selecting different starting point at each iteration. In this paper, we propose to find the optimal approximation of a cyclically extended closed curve of double size, and to select the best possible starting point by search in the extended search space for the curve. The proposed approach provides solution very close to the optimal one using at most twice as much time as required by the optimal algorithm for the corresponding open curve.     

Attention And Positional Encoding Are (Almost) All You Need For Shape Matching

The fast development of novel approaches derived from the Transformers architecture has led to outstanding performance in different scenarios, from Natural Language Processing to Computer Vision. Recently, they achieved impressive results even in the challenging task of non-rigid shape matching. However, little is known about the capability of the Transformer-encoder architecture for the shape matching task, and its performances still remained largely unexplored. In this paper, we step back and investigate the contribution made by the Transformer-encoder architecture compared to its more recent alternatives, focusing on why and how it works on this specific task. Thanks to the versatility of our implementation, we can harness the bi-directional structure of the correspondence problem, making it more interpretable. Furthermore, we prove that positional encodings are essential for processing unordered point clouds. Through a comprehensive set of experiments, we find that attention and positional encoding are (almost) all you need for shape matching. The simple Transformer-encoder architecture, coupled with relative position encoding in the attention mechanism, is able to obtain strong improvements, reaching the current state-of-the-art.