Precise determination of promethazine hydrochloride (PM) is essential due to its common use in various pharmaceutical formulations. Considering their analytical properties, solid-contact potentiometric sensors could represent an appropriate solution to the problem. The objective of this research project was to design a solid-contact sensor enabling the potentiometric measurement of PM. A liquid membrane contained hybrid sensing material, the core components of which were functionalized carbon nanomaterials and PM ions. The new PM sensor's membrane composition was enhanced by experimenting with different membrane plasticizers and modifying the sensing material's content. Experimental data, alongside calculations of Hansen solubility parameters (HSP), informed the plasticizer selection. Cell Cycle inhibitor Employing a sensor incorporating 2-nitrophenyl phenyl ether (NPPE) as plasticizer and 4% of the sensing material yielded the most impressive analytical results. The system's performance was marked by a Nernstian slope of 594 mV per decade, enabling its operation over a broad working range from 6.2 x 10⁻⁷ M to 50 x 10⁻³ M. It featured a low limit of detection at 1.5 x 10⁻⁷ M, along with a fast response time of 6 seconds, minimal drift rate of -12 mV/hour, and exceptional selectivity. The sensor demonstrated reliable performance for pH values situated between 2 and 7. The new PM sensor's application yielded accurate PM measurements in pure aqueous PM solutions and pharmaceutical products. Potentiometric titration, along with the Gran method, was used for this task.
High-frame-rate imaging, employing a clutter filter, provides a clear visualization of blood flow signals, enabling a more efficient distinction between these and tissue signals. Studies using in vitro high-frequency ultrasound, with clutter-less phantoms, indicated that evaluating the frequency dependency of the backscatter coefficient could potentially assess red blood cell aggregation. Nonetheless, in vivo applications demand the filtering of extraneous signals to visualize the echoes produced by red blood cells. This study's initial investigations involved assessing the effects of the clutter filter within the framework of ultrasonic BSC analysis, procuring both in vitro and preliminary in vivo data to elucidate hemorheology. For high-frame-rate imaging, a coherently compounded plane wave imaging process was implemented with a frame rate of 2 kHz. The in vitro study used two samples of red blood cells, suspended in saline and autologous plasma, which were circulated in two types of flow phantoms, either with or without simulated clutter signals. Cell Cycle inhibitor Singular value decomposition was employed to eliminate the disruptive clutter signal from the flow phantom. The BSC was parameterized by spectral slope and mid-band fit (MBF) values between 4-12 MHz, following the reference phantom method. Employing the block matching technique, a velocity distribution was assessed, and the shear rate was ascertained through a least squares approximation of the slope proximate to the wall. Consequently, the spectral gradient of the saline sample held steady at approximately four (Rayleigh scattering), uninfluenced by the applied shear rate, because red blood cells did not aggregate in the solution. In contrast, the spectral slope of the plasma sample was below four at low shear rates; however, it tended toward four as the shear rate was increased, likely as a consequence of the high shear rate's ability to dissolve the aggregations. The MBF of plasma samples decreased from -36 dB to -49 dB, across both flow phantoms, as shear rates escalated from about 10 to 100 s-1. In healthy human jugular veins, in vivo studies showed similar spectral slope and MBF variation to the saline sample, given the ability to separate tissue and blood flow signals.
The failure to account for the beam squint effect in millimeter-wave broadband systems leads to low estimation accuracy under low signal-to-noise ratios. This paper proposes a model-driven channel estimation method for millimeter-wave massive MIMO broadband systems to address this issue. This method's consideration of the beam squint effect involves applying the iterative shrinkage threshold algorithm to the deep iterative network. Employing a training data-based learning process, the millimeter-wave channel matrix is transformed into a sparse matrix representation in the transform domain. Regarding beam domain denoising, a contraction threshold network, incorporating an attention mechanism, is presented in the second phase. In response to feature adaptation, the network identifies a set of optimal thresholds, which can be adjusted for various signal-to-noise ratios to bolster denoising effectiveness. The residual network and the shrinkage threshold network are optimized together in the final stage to accelerate the convergence process of the network. Simulation outcomes demonstrate a 10% acceleration in convergence rate and a remarkable 1728% improvement in average channel estimation precision, irrespective of the signal-to-noise ratio.
An innovative deep learning processing pipeline is presented in this paper, targeting Advanced Driving Assistance Systems (ADAS) for urban mobility. An in-depth examination of the fisheye camera's optical configuration and a detailed protocol are used to acquire Global Navigation Satellite System (GNSS) coordinates and the speed of moving objects. The camera's transform to the world coordinate frame integrates the lens distortion function. Re-training YOLOv4 with ortho-photographic fisheye images allows for the precise detection of road users. Easily disseminated to road users, the information our system gathers from the image forms a minor data payload. In low-light conditions, our system achieves real-time classification and precise localization of detected objects, as evidenced by the results. An observation area of 20 meters in length and 50 meters in width will experience a localization error approximately one meter. The FlowNet2 algorithm, employed for offline velocity estimations of the detected objects, produces results with an accuracy sufficient for urban speed ranges, typically with errors below one meter per second for velocities between zero and fifteen meters per second. Furthermore, the near-orthophotographic design of the imaging system guarantees the anonymity of all pedestrians.
The time-domain synthetic aperture focusing technique (T-SAFT) is combined with in-situ acoustic velocity extraction via curve fitting to generate enhanced laser ultrasound (LUS) image reconstructions. Numerical simulation reveals the operational principle, which is further corroborated by experimental results. An all-optical ultrasonic system, utilizing lasers for both the stimulation and the sensing of ultrasound, was established in these experiments. By fitting a hyperbolic curve to the B-scan image of a specimen, its acoustic velocity was extracted in its original location. Cell Cycle inhibitor The in situ acoustic velocity data facilitated the precise reconstruction of the needle-like objects implanted within a chicken breast and a polydimethylsiloxane (PDMS) block. Experiments concerning the T-SAFT process reveal that determining the acoustic velocity is important, not only for identifying the precise depth of the target, but also for producing images with high resolution. This study is foreseen to lead the way in the development and utilization of all-optic LUS for bio-medical imaging.
Wireless sensor networks (WSNs) are a key technology for ubiquitous living and are continually investigated for their wide array of uses. Energy awareness will be indispensable in achieving successful wireless sensor network designs. Clustering, a pervasive energy-saving approach, yields numerous advantages, including scalability, energy efficiency, reduced latency, and extended lifespan, yet it suffers from the drawback of hotspot formation. A method of unequal clustering (UC) is presented as a solution to this. Cluster size in UC varies in relation to the proximity of the base station. An innovative unequal clustering scheme, ITSA-UCHSE, is introduced in this document, leveraging a refined tuna-swarm algorithm to eradicate hotspots in an energy-efficient wireless sensor network. Employing the ITSA-UCHSE technique, the objective is to alleviate the hotspot problem and the unequal energy consumption patterns in WSNs. This research utilizes a tent chaotic map in conjunction with the conventional TSA to generate the ITSA. The ITSA-UCHSE process additionally calculates a fitness value that depends on the metrics of energy and distance. In addition, the ITSA-UCHSE approach to cluster size determination helps in mitigating the hotspot problem. To illustrate the improved efficiency of the ITSA-UCHSE approach, a sequence of simulations were carried out. The simulation data clearly points to improved results for the ITSA-UCHSE algorithm compared to the performance of other models.
As Internet of Things (IoT) applications, autonomous driving, and augmented/virtual reality (AR/VR) services become more demanding, the fifth-generation (5G) network is anticipated to play a critical role in communication. The latest video coding standard, Versatile Video Coding (VVC), contributes to high-quality services by achieving superior compression, thereby enhancing the viewing experience. To effectively enhance coding efficiency in video coding, inter bi-prediction generates a precise merged prediction block. Despite the presence of block-wise methods like bi-prediction with CU-level weight (BCW) within VVC, linear fusion approaches encounter difficulty in capturing the varied pixel patterns within a block. A pixel-level technique, bi-directional optical flow (BDOF), is presented to refine the bi-prediction block in a more sophisticated manner. Nevertheless, the nonlinear optical flow equation, utilized in BDOF mode, is subject to assumptions, thus hindering the method's capacity for precise compensation of diverse bi-prediction blocks. Within this paper, we advocate for an attention-based bi-prediction network (ABPN) as a replacement for existing bi-prediction approaches.