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This paper examines the impact of various parameters, including frames, zigzag number, and enclosure shape, on the solidification process and thermal energy storage rate of a vertical phase change material (PCM) container. The study also assesses the effects of the flow rate of the heat transfer fluid as well as changing the materials of the PCM between RT35 and RT35HC. In addition, the study compares the framed versus unframed systems and, subsequently, the best case was tested with various zigzag pitch numbers before changing the zigzag-shaped structure to arc and reversed-arc. The findings are examined by contrasting the different scenarios’ liquid fractions, temperature distributions, solidification rates, and heat storage rates. The results show that the framed geometry is 66% faster to reach the target temperature compared with the unframed geometry and employing a zigzag enclosure in a PCM can significantly improve the solidification time and heat recovery rate. As the number of pitches in the zigzag enclosure increases, the improvement rate decreases but still improves the solidification time and heat recovery rate. The reversed-arc-shaped structure has the best performance compared with the other undulated surfaces. For the system with RT35HC, the discharge time is 55% higher compared with that of the system with RT35, while the discharge rate is 8.2% higher for the former during the first 3000 s of the discharging process.Graphical Abstract

Since designing aircraft flight controllers is complex, expensive, and time consuming, the interchangeability of flight controllers between different aircraft platforms has been an active research area. This work presents the development of interchangeable, verifiable flight controllers for fixed-wing unmanned aircraft systems (UASs). A model-free deep reinforcement learning (RL) algorithm—called proximal policy optimization—trains the RL-based control policy. Instead of using high-fidelity dynamic models, the RL policy-based controller is trained in simulation using an engineering-level dynamic model. The robustness of the flight controller toward uncertainty in the dynamic model is improved using randomization of the dynamic model. An aircraft's six degrees of freedom model is used in training to eliminate the heavy reliance of modern controllers on dynamic models, which are prone to the accuracy of the trim information. The idea of an interchangeable flight controller is developed by incorporating memory functions into the policy using long-short-term memory, a variant of recurrent neural network architecture. The developed flight controller is uniquely verified and validated in actual flight tests using fixed-wing autonomous aircraft. The interchangeable RL-based flight controller is flight-tested on an entirely different aircraft, which is the first of its kind. Its performance is superior to commercial-off-the-shelf flight controllers and linear quadratic regulator (LQR)-based flight controllers explicitly designed for that platform. Flight test validation and verification data are used to assess flight controller performance and the comparison matrices.

Maintaining and modulating mechanical anisotropy is essential for biological processes. However, how this is achieved at the microscopic scale in living soft matter is not always clear. Although Brillouin light scattering (BLS) spectroscopy can probe the mechanical properties of materials, spatiotemporal mapping of mechanical anisotropies in living matter with BLS microscopy has been complicated by the need for sequential measurements with tilted excitation and detection angles. Here we introduce Brillouin light scattering anisotropy microscopy (BLAM) for mapping high-frequency viscoelastic anisotropy inside living cells. BLAM employs a radial virtually imaged phased array that enables the collection of angle-resolved dispersion in a single shot, thus enabling us to probe phonon modes in living matter along different directions simultaneously. We demonstrate a precision of 10 MHz in the determination of the Brillouin frequency shift, at a spatial resolution of 2 µm. Following proof-of-principle experiments on muscle myofibres, we apply BLAM to the study of two fundamental biological processes. In plant cell walls, we observe a switch from anisotropic to isotropic wall properties that may lead to asymmetric growth. In mammalian cell nuclei, we uncover a spatiotemporally oscillating elastic anisotropy correlated to chromatin condensation. Our results highlight the role that high-frequency mechanics can play in the regulation of diverse fundamental processes in biological systems. We expect BLAM to find diverse applications in biomedical imaging and material characterization.

The pelvis plays a significant role in creating smooth and efficient motion during gait. In this study, an orthosis is designed to support pelvis motion of patients with the inability to walk. This assistive device is un-powered and consists of only passive elements. By focusing on the motion of the lower extremities during treadmill walking, a 3D dynamic model of the human body is simulated through a coupled optimization process. Based on two approaches of direct and inverse dynamics, the optimization problems are defined to derive optimum structural parameters of the pelvic orthosis. The optimization results of the direct dynamics problem indicate good matches between the optimized time plots of pelvis rotations with corresponding desired ones. Moreover, by solving the inverse dynamics problem, the minimum value of torque vector of the hip joint of the stance leg during a gait cycle is obtained. Furthermore, by utilizing a prototype of the orthosis, preliminary experiments are conducted on a normal user to validate the model and to investigate the feasibility of using the device for rehabilitation. For this purpose, the rotational movements of the pelvis and energy consumption of the subject in two cases with and without the device are compared during gait on a treadmill. Decreased energy consumption and the compliant motion of the pelvis while using the device verify simulation results and confirm the favorable performance of the assistive device for pelvic support during walking rehabilitation.

High loading capacity and smart release of inhibitors are the first and foremost characteristics of nanocontainers, which play a pivotal role in metal active corrosion protection. The present work explores the development of novel protective nanocontainers based on recently emerged covalent organic frameworks (COFs). These highly porous frameworks with large surface area, outstanding thermomechanical properties, low density, and ease of functionalization are used as nanocontainers. On the other hand, molybdenum disulfide (MoS2), a state-of-the-art 2D layered compound with a sheetlike structure, was utilized thanks to its excellent barrier properties. However, these lamellar structures suffer a high agglomeration tendency in polymeric matrices. Therefore, we developed a novel hybrid nanocontainer, inspired by natural nacre, by an in situ growth of COF on MoS2to improve the stability and provide a high inhibitor loading capacity. The porous and nitrogen-rich structure of COF made it a good carrier to adsorb europium cations as inorganic inhibitors and release them on demand by pH changes to suppress the electrochemical reactions. The as-synthesized nanoplatforms were used as pH-responsive fillers in the epoxy resin. The nanocomposite coatings showed almost 50 kΩ cm2total resistance and high impedance values (1011Ω cm2) even after 77 days of immersion. Moreover, salt spray analysis depicted the smallest amount of rust and corrosion product after 31 days in the filled nanocomposite coating. Cathodic delamination and pull-off outcomes denoted that the filled coatings with the as-synthesized nanofiller showed the smallest cathodic delamination radius (3.41 mm) and lowest adhesion loss (24%) compared to the neat epoxy (7.55 mm and 46.7%). As such, the highly porous modified MoS2nanosheets are considered promising alternatives in a wide range of applications with anticorrosion properties.

Purpose: Menstrual blood-derived stem cells (MenSCs), a novel source of mesenchymal stem cells (MSC)s which can be extracted from the menstrual fluid by a simple and non-invasive approach, and without ethical concerns. Optogenetics is a biological tool for controlling ion flux by light in various cells, including stem cells. This study aims to evaluate the osteogenic differentiation of MenSCs by optogenetic manipulation. Methods: The MenSCs were transduced with lentivirus vector carrying channelrhodopsin-2 [hChR2 (H134R)]. ChR2-expressing MenSCs were illuminated with blue light (470 nm) with 1 mW power for 1 h. Several control groups, including non-ChR2-expressing MenSCs in conventional culture medium and osteogenic medium with dark and optical control, were subjected in this study. A day after light illumination, the viability of cells and intracellular calcium (Ca2+) level was evaluated by the MTT assay, and spectrophotometer, respectively. The Ca2+deposition and alkaline phosphatase activity also were examined on days 7, 14, and 21. The expression of osteogenic genes Runx2, osteopontin, and osteocalcinwere analyzed by quantitative PCR. Results: 72 h after infection, MenSCs were effectively transduced using lentiviral vector. In comparison to other groups, optogenetic activated ChR2-expressing MenSCs showed significantly higher viability in the MTT experiment. Additionally, optogenetic stimulation increased intracellular Ca2+concentration and deposition, as well as alkaline phosphatase activity (ALP). Optical stimulation also promoted the production of osteogenic genes such Runx2, osteocalcin, and osteopontin. Conclusion: Optical stimulation could increase the intracellular Ca2+level, ALP activity, cell viability, and up-regulation of Runx2, osteocalcin, and osteopontin, which play an important role during osteogenesis. Hence, the results of present study may provide a new strategy forbone regeneration and regenerative medicine.

LuGre friction model is a comprehensive model for friction, which can simulate important nonlinear phenomena such as stiction, Stribeck effect, variable break-away force, pre-sliding displacement, and frictional lag. In this paper, an analytical describing function (DF) for this friction model is derived. The theoretical analysis is examined by comparing its result with some existing experimental results. The determined DF can approximate the LuGre friction force with constant viscous damping in a sinusoidal motion. Afterwards, as an application, its effect on the stability of a haptic device (HD) is studied. For this purpose, some simulations in MATLAB software are performed by considering the HD as a one-degree of freedom system with an effective mass that moves with the LuGre friction model, and stability analysis is performed theoretically (using the DF of the LuGre) and compared with the simulation result.

Cyclic motions are fundamental patterns in robotic applications, including industrial manipulation and robot locomotion. This article proposes an approach for the online modulation of cyclic motions in robotic applications. For this purpose, we present an integrated programmable central pattern generator (CPG) for the online generation of the reference joint trajectory of a robotic system out of a library of desired periodic motions. The reference trajectory is then followed by the lower level controller of the robot. The proposed CPG generates a smooth reference joint trajectory convergence to the desired one while preserving the position and velocity joint limits of the robot. The proposed CPG consists of one novel bounded output programmable oscillator. We design the programmable oscillator for encoding the desired multidimensional periodic trajectory as a stable limit cycle. We also use the state transformation method to ensure that the oscillator’s output and its first time-derivative preserve the joint position and velocity limits of the robot. With the help of Lyapunov-based arguments, we prove that the proposed CPG provides the global stability and convergence of the desired trajectory. The effectiveness of the proposed CPG for trajectory generation is shown in a passive rehabilitation scenario on the Kuka iiwa robot arm, and also in walking simulation on a seven-link bipedal robot. [ABSTRACT FROM AUTHOR]

Purpose: Due to the importance of public health and economics, cardiovascular disease has become one of the most important debates and challenges for scientists. However, few studies have been done to address this challenge. The main objective of this document is to provide an optimal model to improve the performance of the left ventricular assist device and reduce costs. In this way, in the present study, the experimental and numerical procedures were developed to analyze the effects of the geometrical features and operational parameters on the performance of a centrifugal blood pump (CBP). Methods: In order to achieve this aim, first, experimental tests were carried out to study the influence of the working fluid temperature and the rotational speed on the CBP. Subsequently, the performance of the CBP was assessed using computational fluid dynamics (CFD), and comparison was made against the experimental data. In addition, the influence of mounting an inducer on the overall performance of CBP was also investigated. Results: Good agreement between the CFD and the data was obtained. The CFD results showed that increasing the fluid temperature and rotational speed leads to an increase in the hydraulic efficiency, pressure difference, and power. In addition, the reduction of the pressure difference and hydraulic efficiency with increasing the surface roughness was observed. While mounting an inducer on the pump did not significantly impact its overall performance, the highest value of the wall shear stress dropped moderately on the impeller and, therefore, unveiled the possibility of improving the performance of such designs.

Latent heat thermal energy storage (LHTES) is a promising technology, but thermal response limitations caused by the relatively poor thermal conductivity of phase change materials (PCMs) remains an issue. In recent years, computational fluid dynamics (CFD) has proven to be a powerful and reliable tool in design optimization of different systems and problems in the energy sector. Building on that, the present work will use CFD to investigate the thermal performance enhancements achieved using vertical double-tube LHTES systems with multi-channel sinusoidal wavy geometries. The main parameters investigated here are the wavy channel height (H), pitch (P) and the number of channels (N) and the results are assessed in terms of melting rates and heat transfer coefficients. The analysis found that increasing the height from 1 mm to 3 mm, accelerated the phase change by 21 %, while reducing the pitch from 12.5 mm to 5 mm, enhanced the heat storage rates by 28 %. In addition, increasing the number of channels from 3 to 7 improved the charging rate by 64 %. Compared to a conventional straight channel, the enhanced wavy channel (N = 7, H = 3 mm, P = 5 mm) achieved 80 % higher thermal storage rate and 42 % faster charging time. The above findings provide new insight into the potential of utilizing compact vertical LHTES systems via customized wavy channels, with significant impact towards enhancing the existing thermal energy storage systems.

The core idea of this study is developing a reliable method to manually guide robots in the physical cooperation scenarios, having human safety in priority. To this end, a safe human–robot cooperation algorithm in the presence of physical intentional interactions without employing force and vision sensors is developed. The physical interaction is recognized and controlled through available common sensors. Contact occurrence and its position are investigated by using online external torque vector obtained by residual based observer. Then, the force vector is estimated and employed in the suggested controller for manually guiding the robot. To completely handle the cooperation phase, four guiding scenarios based on actual conditions are recommended. Performance of the proposed controller-observer method during manipulation has been validated through multiple experiments on a KUKA LBR iiwa.

Regards to the complexity of healthcare systems, it is very important to apply accurate and effective methods to manage probable risks to enhance patient safety. The aim of this study is to identify probable risks by using failure modes, effects analysis method and fuzzy analytic hierarchy process to compare obtained results and define shortages of experts' judgment methods. This study has been conducted in electrocautery surgery in an operating room at a hospital in Iran. The failures modes, their effects and causes are identified by in-depth interviews, hospital documentation and fuzzy Delphi method. Obtained results show that decision making based on experts' judgment methods may lead to different results, therefore applying accurate quantitative methods to enhance reliability and patients' safety is essential. While this study identifies the potential risks of a complex surgery, comparing the obtained results based on two methods is the most important contribution of this paper.

Manipulation and secure transportation of loads by robotic manipulators along predetermined paths is still an open challenge in the robotics field. In this article, the problem of pushing and driving an object on a surface employing a robot to reach a specific destination is considered under a-priori unknown friction conditions. For this purpose, the equations of motion are derived according to the limit surface conceptualization of friction force. Although friction parameters may be considered locally constant, nonetheless they gradually vary over large surfaces. The friction term is thus faced with a slowly time-varying indeterminacy and needs an online estimation scheme. By defining a mission consisting of pushing an object via a robot to find a path among obstacles, an optimum path is firstly planned then a non-linear model predictive controller is used to track the desired path. In order to alleviate the indeterminacy due to friction, the corresponding terms in the equations of motion are set as a disturbance which is estimated by a purposely designed observer and then eliminated in a feedforward manner. There is also no need to perform preliminary offline tests.

Friction exists in any moving body, such as manipulator joints. Haptic devices (HDs) are manipulators that can simulate virtual objects for their operators and have different applications in education, medical, and entertainment areas. The existence of friction and inertia in HDs is unavoidable. The friction and effective mass of the HDs decrease the transparency of simulating virtual objects. The Gaussian friction model includes nonlinear phenomena like stiction and the Stribeck effect. In this research, a describing function (DF) for the Gaussian friction model is obtained. Afterward, as an application, this determined DF is used in the stability analysis of a HD to consider the effect of nonlinear friction on its stability boundary. This yields the derivation of a closed-form equation to predict the stability boundary without any limitations on time delay and virtual damping, including nonlinear phenomena such as stiction and the Stribeck effect. Afterward, the determined stability equations were verified by simulations with different time delays and virtual damping with good precision. Also, performing experiments on a HD shows that by using the new DF, the experimental results are predicting approximately %80better, compared with the case of not using this DF.

The aim of the study was to assess the professional behavior of dental residents through Professionalism Mini‐Evaluation Exercise (P‐MEX). This was a descriptive‐analytical study. Content validity of P‐MEX form was investigated for use in the context of dentistry. A total of 24‐item version of P‐MEX consisted of doctor–patient relationship skills (n = 7), reflective skills (n = 5), time management (n = 3), and interprofessional relationship skills (n = 9) was used in the present study. Residents in different dental specialties (n = 56) were evaluated by trained raters (448 times). Data were analyzed by descriptive (mean, SD) and analytical tests (Pearson, ANOVA, and post hoc test (Bonferroni)). Validity of P‐MEX was approved in the field of dentistry. The mean score of professional behavior in residents were reported 2.79 ± 0.24, with minimum and maximum scores of 2.17 and 3.62, respectively. The residents' professional behavior in the domain of reflective skills and doctor–patient relationship skills were lower than the other domains. The results showed that the scores of professional behavior among dental residents were classified in the below expectation level and their scores have followed a downward trend from the second year. Therefore, planning for training and continuous assessment of professional behavior among residents in the faculty of dentistry should be considered.

Introduction: Nano drug delivery is a broad field of research on the development of novel nano- carrier systems for effective therapeutic delivery of drugs. Here, an anticancer drug, cisplatin (CDDP) conjugated Gold Nanoparticles (GNPs) via L-Lysine (Lys) linker. Methods: The produced nanodrug (GNPs-Lys-CDDP) was characterized by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta potentials and electron force microscopy. The cytotoxic efficacy of the GNPs-Lys-CDDP against human breast cancer cells (SKBR3) and normal cells (MCF- 10A) was evaluatedby MTT assay. Cell apoptosis and morphology changes were assessed by flowcytometery and Acridine Orange/Ethidium Bromide (AO/EtBr) staining, respectively. Results: It was found that the GNPs-Lys-CDDP with a size of 85 nm and negatively charged with a zeta-potential of about -25 mV could be taken up by tumor cells. A marked change in the UV spectrum of GNPs-Lys-CDDP compare to GNPs showed a strong absorption shift in the 525 nm region. The LD 50 of GNPs-Lys-CDDP against SKBR3 (1 μg.mL -1), was found to be 8 times lower than that of naked CDDP against SKBR3 (8 μg.mL -1). The nanocomplex GNPs-Lys-CDDP also significantly increased the apoptosis of SKBR3 with the lowest cytotoxic effects on normal cells. Discussion: This work indicates that GNPs effectively could decrease the lethal dose of CDDP to 87%. Hence, GNPs modified by Lys, could be a good nano-carrier for chemotherapeutic drugs.

Investigating group-IV-based photonic components is a very active area of research with extensive interest in developing complementary metal-oxide-semiconductor (CMOS) compatible light sources. However, due to the indirect band gap of these materials, effective light-emitting diodes and lasers based on pure Ge or Si cannot be realized. In this context, there is considerable interest in developing group-IV based Raman lasers. Nevertheless, the low quantum yield of stimulated Raman scattering in Si and Ge requires large device footprints and high lasing thresholds. Consequently, the fabrication of integrated, energy-efficient Raman lasers is challenging. Here, we report the systematic investigation of stimulated Raman scattering (SRS) in Ge nanowires (NWs) and axial Al-Ge-Al NW heterostructures with Ge segments that come into contact with self-aligned Al leads with abrupt metal–semiconductor interfaces. Depending on their geometry, these quasi-one-dimensional (1D) heterostructures can reassemble into Ge nanowires, Ge nanodots, or Ge nanodiscs, which are monolithically integrated within monocrystalline Al (c-Al) mirrors that promote both optical confinement and effective heat dissipation. Optical mode resonances in these nanocavities support in SRS thresholds as low as 60 kW/cm2. Most notably, our findings provide a platform for elucidating the high potential of future monolithically integrated, nanoscale low-power group-IV-based Raman lasers.

An extensive study of capillary flow of fluids with various viscosities in straight and periodically constricted microchannels with different surface wettability is presented. Capillary filling speed in hydrophilic, less hydrophilic, and hydrophobic microchannels were experimentally monitored and compared with the Washburn theoretical model. For all liquids, a linear relationship was found between the square of propagation distance and time, which is expected for Newtonian fluids. Experimental results indicated slower velocity compared to the theoretical prediction due to simplifications of the Washburn model. Capillary filling speed of fluids into long-fluororinated chain silane modified channels confirmed the expected lyophobic nature of the coating (i.e., not favorable for either hydrophilic or hydrophobic liquids). Presence of the precursor film ahead of the three-phase contact line in the microscopic level was demonstrated. White light and fluorescent images confirmed the presence of precursor film and capillary evaporation at the interface. Evaporation enhanced the deviation between experimental and theoretical results due to continuous wettability alteration of penetrating fluid.

The present work explores the impact of tip clearance on the mean blade height ratio, inlet tip blade angle, and surface roughness of the inducer. The objective is to find an optimized inducer to limit the secondary flow over the blades, which in turn improves the pump efficiency and reduces the life cycle costs. A numerical framework is developed to investigate efficient operational and geometrical parameters on an inducer's cavitation and non-cavitation presentations. The catalyser functioning is simulated by applying a 3D CFD model, and the results are assessed against empirical data. The results show a reliable agreement with empirical data and suggest that the increment of tip clearance in the mean blade height ratio causes the hydraulic performance and the analytical cavitation number to decline in cavitation and non-cavitation conditions. Moreover, the optimum value of 85ois found for the inlet tip blade angle, which improves the non-cavitation performance.

•T cells from bone marrow egress to blood during SCM and preferentially home back to marrow after adoptive transfer.•Treg depletion during SCM expands polyfunctional effector T cells in mobilized grafts and enhances antimyeloma immunity after ASCT.

In this work, the compatibility of poly(dimethylsiloxane) (PDMS) with high viscosity petroleum liquids (bitumen) was evaluated to study the possibility of using PDMS microchannels in heavy oil and bitumen extraction research using solvent based methods such as Vapor Extraction. Three curing agent to base ratios (1:2, 1:10, and 1:20) were used to fabricate PDMS. Swelling ratio of these three samples in the vicinity of different organic solvents and diluted bitumen were evaluated by measuring the weight of sample every 15 min. It was found that 1:10 ratio PDMS was preferential ratio for minimizing absorption. We were particularly interested in the kinetic of swelling, deformation, and discoloration of PDMS. The hypothesis was that a PDMS microchip can still be used for experiments with heavy oil and bitumen if the experiment time is much shorter than the time it takes for PDMS discoloration, swelling, and deformation. The coating of PDMS slabs with trichloro (1 h 1 h 2 h 2 h-perfluorooctyl) silane was also tested and swelling ratios were again measured to evaluate the effect of surface coating. Swelling ratios were at the same order for uncoated PDMS which shows silane coating is not able to improve the solvent compatibility of PDMS. Moreover, solubility parameter was used to predict the swelling ratio of 1:10 PDMS sample in organic solvents. It predicts that hexane and toluene have the highest solubility that was in great agreement with experimental results. It seems that solubility parameter is a reliable factor to qualitatively predict the swelling ratio of PDMS. The effect of bitumen on transparency of PDMS was also studied using Ultraviolet–Visible spectrophotometer.

Mehdi Keshmiri, MD(*); H Baharvahdat, MD; S H Fattahi, MD; B Davachi, MD; H Bradaran, MD; R H Dabiri, MD and F Rajzbzadeh, MD. Mashad University of Medical Sciences - [...]

The combination of Moore’s law and Dennard’s scaling rules have constituted the fundamental guidelines for the silicon-based semiconductor industry for decades. Furthermore, the enormous growth of global data volume has pushed the demand for complex and densely packed devices. In recent years, it has become clear that wired interconnects impose increasingly severe speed and power limitations onto integrated circuits as scaling slows toward a halt. To overcome these limitations, there is a clear need for optical data processing. Despite significant progress in the development of silicon photonics, light sources remain challenging owing to the indirect bandgap of group IV materials. It is therefore highly desirable to develop new concepts for a silicon light source that meets efficiency and footprint requirements similar to their electronic counterparts. Here, we demonstrate an electrically driven and tunable silicon light source by matching the resonant modes of a silver nanocavity with the hot luminescence spectrum of an avalanching p–n junction. The cavity significantly enhances phonon-assisted recombination of hot carriers by tailoring the local density of states at the size-tunable resonance. Such tunable nanoscale emitter may be of great interest for short-reach communications, microdisplays or lab-on-chip applications.

Computational fluid dynamics is a tool capable of accurately measuring metrics currently used to predict the behaviour of cardiovascular diseases. This study quantifies the impact various commonly used inlet and outlet boundary conditions have on various shear rate–based haemodynamic metrics currently used for predicting the localisation of cardiovascular diseases. Simulations are conducted on an accurately represented rabbit aorta configuration and comparison has been made against available in vivodata. The boundary conditions studied include two different inlet profiles, three outlet boundary conditions, and steady-state versus pulsatile flow cases. Large variations were found in the results, particularly when using different outlet boundary conditions, and the discrepancies were evaluated both quantitatively and qualitatively. The results clearly highlight the importance of the type of boundary condition used when simulating complex cardiovascular models. By restricting the attention to the flow within the aorta and the intercostal branches, the results suggest that prescribing transient simulation and fully developed flow at the inlet are not required. Furthermore, assuming the widely accepted low wall shear stress theory of Caro, it was found that Murray’s law–based outlet boundary condition returns the most physiologically accurate results when compared to in vivodata.

The present research was conducted to develop a potent electrochemical sensor based on multi-walled carbon nanotubes and TiO2 nanoparticles in chitosan matrix (CS-MWCNTs+TiO2NPs). In the CS-MWCNTs+TiO2NPs nanocomposite film with excellent catalytic activities, good electrical conductivities and high surface areas of MWCNTs and TiO2NPs, the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RS) with proper analytical performance was realized in the individual or triple-components solution in comparison with the bare glassy carbon electrode (GCE) and the single component modified GCE. The linear response of HQ, CC and RS were obtained in the ranges of 0.4-276.0 umol dm[?]3, 0.4-159.0 umol dm[?]3 and 3.0-657 umol dm[?]3 and the detection limits (S/N = 3) were 0.06 umol dm[?]3, 0.07 umol dm[?]3, and 0.52 umol dm[?]3, respectively. In the real water sample analysis by the developed sensor, satisfactory results were obtained.

This work presents mathematical and practical frameworks for designing deep deterministic policy gradient (DDPG) flight controllers for fixed-wing aircraft. The aim is to design reinforcement learning (RL) flight controllers and accelerate training by substituting the six degrees-of-freedom aircraft models with linear time-invariant (LTI) dynamic models. The initial validation flight tests of the DDPG RL flight controller exhibited poor performance. Post-flight test investigation revealed that the unsatisfactory performance of the RL flight controller could be attributed to the high reliance of the LTI model on accurate control trim values and the substantial errors observed in the predicted trim values generated by the engineering-level dynamic analysis software. A complementary real-time learning Gaussian process (GP) regression was designed to mitigate this critical shortcoming of the LTI-based RL flight controller. The GP estimates and updates the trim control surfaces using observed flight data. The GP regression method incorporates real-time corrections to the trim control surfaces to enhance the performance of the flight controller. Flight test validation was repeated, and the results show that the RL controller, bolstered by the GP trim-finding algorithm, can successfully control the aircraft with excellent tracking performance.

Predicting prognosis is a cornerstone in management of pulmonary arterial hypertension. Hemodynamic parameters are among the robust indicators of right ventricular function and prognosis. In this study we have investigated the association of a simple hemodynamic parameter with clinical worsening in pulmonary arterial hypertension.

Abstract

End-tidal carbon dioxide (ETCO2) monitoring is useful in many situations. However, ETCO2monitoring is unreliable in patients with acute respiratory distress syndrome (ARDS) due to widespread lung inflammation. In our study, we attempt to establish the gradient between the arterial pressure of carbon dioxide (PaCO2) and ETCO2in patients with ARDS, which we defined as the PaETCO2gradient. The main objective of the study was to establish a PaETCO2gradient in each severity of ARDS. We analyzed 35 patients with ARDS and a total of 88 arterial blood gases were included. PaCO2, PaO2/FiO2and ETCO2were measured. Patients were stratified into mild, moderate and severe ARDS as classified by the Berlin ARDS criteria. PaCO2and ETCO2were compared at each severity stratification. The mean PaCO2was 50.0, the mean ETCO2was 26.6 and the gradient among all samples was 23.24 (±12.02). The mean gradient for each severity is as follows: mild: 19.3 (±9.9), moderate: 27.9 (±13.2) and severe: 23.9 (±7.8). The difference between the PaETCO2gradient of the mild to moderate (p=0.001) and mild to severe groups (p=0.01) reached statistical significance. However, the difference between the moderate to severe groups did not reach statistical significance (p=0.48). We found the gradient between PaCO2and ETCO2in patients with ARDS is vast and tends to worsen with increasing severity of ARDS. This indicates that the gradient between the 2 may be used as an indicator of increasing severity of ARDS.

Cell voltage equalizers are an important part in electric energy storage systems comprising series-connected cells, for example, supercapacitors. Hybrid electronics with silicon chips and printed devices enables electronic systems with moderate performance and low cost. This paper presents a silicon-organic hybrid voltage equalizer to balance and protect series-connected supercapacitor cells during charging. Printed organic electrochemical transistors with conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) are utilized to bypass excess current when the supercapacitor cells are fully charged to desired voltages. In this study, low-cost silicon microcontrollers (ATtiny85) are programmed to sense voltages across the supercapacitor cells and control the organic electrochemical transistors to bypass charging current when the voltages exceed 1 V. Experimental results show that the hybrid equalizer with the organic electrochemical transistors works in dual-mode, switched-transistor mode or constant-resistor mode, depending on the charging current applied (0.3–100 mA). With the voltage equalizer, capacitors are charged equally regardless of their capacitances. This work demonstrates a low-cost hybrid solution for supercapacitor balancing modules at large-scale packs.

Beim Gelenkersatz des älteren Menschen gilt es, Besonderheiten zu beachten. Angefangen von der Indikationsstellung, der präoperativen Vorbereitung, der Implantatauswahl bis hin zur intraoperativen Technik, Nachbehandlung sowie zu den klinischen Ergebnissen, zeigen sich teils erhebliche Unterschiede zu jüngeren Patienten. Aufgrund der deutlichen Diskrepanz zwischen chronologischem und biologischem Alter beim älteren Menschen, verbunden mit dem Aktivitätsniveau und dem Anspruch an das Kunstgelenk, ist es wichtig, das Vorgehen individuell auf den Patienten abzustimmen. Ungeachtet des Patientenalters stehen sämtliche Endoprothesenmodelle mit den implantatspezifischen Eigenschaften, die es zu beachten gilt, zur Verfügung. Zusammenfassend stehen beim älteren Menschen Attribute wie Stabilität und Schmerzfreiheit im Vordergrund. Special characteristics must be taken into consideration for replacement arthroplasty in the elderly. The indications, preoperative preparation, postoperative care, implant selection, intraoperative technique, as well as clinical results reveal sometimes substantial differences compared to younger patients. Based on these findings it is important to individualize the approach to patient therapy, especially due to distinct differences between chronological and biological age in the elderly, in association with the level of activity and expectations on the new joint. All types of implants, each with implant-specific characteristics that must be taken into consideration, are available independent of the age of the patient. In summary, attributes such as stability and pain-free mobility have to be given priority in the elderly.

The problem of pendular oscillations of a tether attached to an irregularly shaped celestial body is studied in this paper. The dynamic analysis of the system is performed by examining the phase plane trajectories. The effect of the tether length as well as the higher order terms in the gravitational potential of the celestial body on the tether dynamics is investigated. It is demonstrated that consideration of the finite size of the celestial body can have significant effects on the tether dynamics, while the effect of the asphericity of the celestial body on the tether dynamics is negligible. This study is of practical relevance for asteroid deflection using tethers, as well as for the development of space elevators on small planets/moons.

We present a current supply, comprising a single organic thin-film transistor (OTFT), for the charging of supercapacitors. The current supply takes power from the electric grid (115 V AC, US standard), converts the AC voltage to a quasi-constant DC current (~0.1 mA) regardless of the impedance of the load, and charges the supercapacitor. Solution-processed OTFTs based on the popular polymeric semiconductor poly(3-hexylthiophene-2,5-diyl) have been developed to rectify the 115 V AC voltage. A diode-configured OTFT was used as a half-wave rectifier. The single OTFT current supply was demonstrated to charge a 220 mF supercapacitor to 1 V directly using 115 V AC voltage as the input. This work paves the road towards all-printable supercapacitor energy-storage systems with integrated chargers, which enable direct charging from a power outlet.

Die Dyskinesie der Patella stellt ein relevantes Problem nach primärer Knietotalendoprothetik dar. Die Patellanavigation ermöglicht die Darstellung der Patellakinematik intraoperativ in Echtzeit bei dynamischer Untersuchung. In dem Videobeitrag wird die Technik der Patellanavigation bei der Knietotalendoprothetik demonstriert und eine mögliche Konsequenz der Messung dargestellt. Im berichteten Fall zeigt sich nach Implantation ein vermehrter lateraler Tilt nach Implantation der Knietotalendoprothese. Durch eine laterale Retinakulumerweiterungsplastik kann der vermehrte Tilt reduziert werden. In ausgewählten Fällen ist die Patellanavigation geeignet, die Kinematik der Patella intraoperativ vor und nach Prothesenimplantation zu messen. Intraoperativ können dann noch Modifikationen der Implantatpositionierung oder ergänzende Weichteileingriffe eine patellofemorale Dyskinesie verhindern. Patellofemoral maltracking is a relevant problem after total knee arthroplasty (TKA). Patella navigation is a tool that allows real time monitoring of patella tracking. This video contribution demonstrates the technique of patellofemoral navigation and a possible consequence of intraoperative monitoring. A higher postoperative lateral tilt is addressed with a widening of the lateral retinaculum in a particular manner. In selected cases of patellofemoral problems, patella navigation is a helpful tool to evaluate patellofemoral tracking intraoperatively. Modifications of implant position and soft tissue measurements can then prevent postoperative patellofemoral maltracking.

In this retrospective study, the safety of percutaneous endoscopic gastrostomy (PEG) tube placement was evaluated as maintaining adequate nutritional support for patients with left ventricular assist devices is crucial. Nineteen patients who underwent PEG tube placement were followed for an average of 40 days. Overall, minor complications such as infections, bleeding, and PEG tube malposition occurred in just 19% of patients while the rate of major complications such as perforation was 5%. Further randomized control trials are necessary to validate this assertion that the safety of PEG placement in patients with left ventricular assist devices is similar to that of the general population.

New plasmonic structure with actively tunable optical characteristics based on thermoresponsive hydrogel is reported. It consists of a thin, template-stripped Au film with arrays of nanoholes that is tethered to a transparent support by a cross-linked poly(N-isopropylacrylamide) (pNIPAAm)-based polymer network. Upon a contact of the porous Au surface with an aqueous environment, a rapid flow of water through the pores enables swelling and collapsing of the underlying pNIPAAm network. The swelling and collapsing could be triggered by small temperature changes around the lower critical solution temperature (LCST) of the hydrogel. The process is reversible, and it is associated with strong refractive index changes of Δn∼ 0.1, which characteristically alters the spectrum of surface plasmon modes supported by the porous Au film. This approach can offer new attractive means for optical biosensors with flow-through architecture and actively tunable plasmonic transmission optical filters.

The use of Left Ventricular Assistive Devices (LVADs) is increasing for people with heart failure. The present computational fluid dynamics study provides insight into the significance of the flow ratio between the cannula and the aortic root on the prediction of lesion localisation in a typical LVAD configuration, which in turn affects the design and manufacture of these devices. Three cases were studied with varying percentages of flow through the two inlets; the cannula inlet was assumed steady-state, whilst the aortic root inlet had a scaled pulsatile profile, representative of the extent of heart failure. Results suggest that as the flow exiting the heart decreases in velocity, if not orientated properly, the jet exiting the cannula graft can ‘obstruct’ flow to the innominate, common carotid and left subclavian arteries. Therefore, patients with less severe heart failure will generally experience relatively good perfusion of these arteries. However, for the more severe cases of heart failure, the orientation of the cannula graft should be such that adequate perfusion to the aforementioned arteries is maintained.

The design of prosthetic grafts plays an essential role on the hemodynamics through the graft anastomosis. Research has shown that swirling flow, which is caused by the rotational compressive pumping of the heart, is a natural phenomenon in the arterial system and results in removing unfavourable flow environment. Recently, non-planar helical grafts have shown to perform better than grafts with internal spiral ridge in inducing the swirling flow. The present work investigates the importance of the ridge design and in particular, shows that the ridge trailing edge orientation at the anastomosis has significant effects in potentially improving the hemodynamic efficiency of this type of graft.

Active vibration control of a cylindrical shell using piezoelectric disks is studied both theoretically and experimentally in this paper. Hamilton's principle is used for deriving dynamic motion equations of the cylinder coupled with piezoelectric disks. The equations are discretised by Rayleigh-Ritz method. An adaptive feedforward controller based on steepest descent method is implemented on a PC to control the modal vibration. The proposed method solves the drawback of using PCs that is sending and receiving data in block form. It is shown that the proposed control system which consists of piezoelectric disks and an adaptive controller is effective in reducing vibration and radiated acoustic noise.

Femoral stem version has a major influence on impingement and early post-operative stability after total hip arthroplasty (THA).The main objective of this study was to evaluate the validity of a novel radiological method for measuring stem version. Anteroposterior (AP) radiographs and three-dimensional CT scans were obtained for 115 patients (female/male 63/72, mean age 62.5 years (50 to 75)) who had undergone minimally invasive, cementless THA. Stem version was calculated from the AP hip radiograph by rotation-based change in the projected prosthetic neck–shaft (NSA*) angle using the mathematical formula ST = arcos [tan (NSA*) / tan (135)]. We used two independent observers who repeated the analysis after a six-week interval. Radiological measurements were compared with 3D-CT measurements by an independent, blinded external institute.We found a mean difference of 1.2° (sd6.2) between radiological and 3D-CT measurements of stem version. The correlation between the mean radiological and 3D-CT stem torsion was r = 0.88 (p < 0.001). The intra- (intraclass correlation coefficient ≥ 0.94) and inter-observer agreement (mean concordance correlation coefficient = 0.87) for the radiological measurements were excellent.We found that femoral tilt was associated with the mean radiological measurement error (r = 0.22, p = 0.02). The projected neck–shaft angle is a reliable method for measuring stem version on AP radiographs of the hip after a THA. However, a highly standardised radiological technique is required for its precise measurement. Cite this article: Bone Joint J 2015; 97-B:306–11.

This paper presents a new stereo image-based visual servoing (IBVS) controller for a six degrees of freedom (DOF) robot manipulator based on acceleration command. An eye-in-hand stereo vision system is utilized to capture the images of the object and to estimate the depth of the object. A proportional derivative (PD) controller is developed considering the acceleration command. The augmented image-based visual servoing (AIBVS) controller helps the system achieve smoother and more linear image feature trajectories and decrease the risk that the features leave the field of view (FOV). The developed control method also enhances the stability characteristics of the system and the robot's end-effector 3D behaviour. Both simulation and experimental results on a 6 DOF DENSO 6242G robot validate the effectiveness of the proposed stereo AIBVS controller. The comparison with IBVS with monocular vision system demonstrates the improved performance of the proposed system.

The outbreak of COVID-19 has had destructive influences on social and economic systems as well as many aspects of human life. In this study, we aimed to estimate the economic effects of COVID-19 at the individual and societal levels during a fiscal year. This cost of illness analysis was used to estimate the economic burden of COVID-19 in Iran. Data of the COVID-19 patients referred to the hospitals affiliated to Bushehr University of Medical Sciences in 2021 were collected through the Hospital Information System (HIS). The study methodology was based upon the human capital approach and bottom-up technique. The COVID-19 pandemic has resulted in 9711 confirmed hospital cases and 717 deaths in Bushehr province during the study period. The direct and indirect costs were estimated to be $1446.06 and $3081.44 per patient. The economic burden for the province and country was estimated to be $43.97 and $2680.88 million. The results showed that the economic burden of this disease particularly premature death costs is remarkably high. Therefore, in order to increase the resiliency of the health system and the stability in service delivery, preventive-oriented strategies have to be more seriously considered by policymakers.

In this paper, several structures for multilayer Cu (In1−xGax) Se2(CIGS) thin film solar cells are proposed to achieve high conversion efficiency. All of the modeling and simulations were based on the actual data of experimentally produced CIGS cells reported in the literature. In standard CIGS cells with a single absorber layer, the effects of acceptor density and Ga content on device performance were studied, and then optimized for maximum conversion efficiency. The same procedure was performed for cells with two and three sectioned CIGS absorber layers in which Cu and/or Ga contents were varied within each consecutive section. This produces an internal additional electric field within the absorber layer, which resulted in an increase in carrier collection for longer wavelength photons, and hence, improvement in the conversion efficiency of the cell. An increase of approximately 3% in efficiency is predicted for cells with two layer absorbers. For multilayer cells in which Cu and Ga distribution were stepped simultaneously, the improvement could be approximately 3.5%. This improvement is due to; enhanced carrier collection for longer-wavelength photons, and reduced recombination at the heterojunction and back regions of the cell. These results are confirmed by the physics of the cells.

The solidification of 4. 4 t cold work tool steel ingot type X210Cr12 was simulated by Magma software. By the reduction of ingot height, solidification modeling and pouring of a new 3 t ingot were performed and decreasing the porosity formation potential in 3 t ingot in comparison with 4. 4 t ingot on the basis of Niyama criterion was observed which was in good accordance with experimental data. In order to produce sound ingot, a new 2. 8 t ingot mould was designed which includes some parameteric changes in mould such as mould slope, slenderness ratio, mould concavity radius, fillet radius of mould internal corners and feeding diameter to ingot upper diameter ratio. Furthermore, the effects of insulating between kokil and feeding ring and also insulating the outer surface of feeding ring as well as insulating the outer surface of one third of kokil upper part on centerline porosity formation were investigated in both 2. 8 and 4. 4 t ingots. The results show that the ingot which was produced in new designed 2. 8 t mould has a better Niyama pattern and the centerline porosities were eliminated.

The objective of this study is to develop a general finite element formulation associated with an incremental adaptive procedure which established for thermoviscoelastic stress analysis of orthotropic cylinders made of polymers. This paper concerned with development of a numerical algorithm for the solution of the quasistatic initial/boundary value problems involving the linear viscoelastic media with thermal and mechanical deformations. The viscoelastic constitutive equations, represented in an integral form and involving relaxation functions, are transformed into an incremental algebraic relation. An incremental relaxation is then developed for the finite element formulation to deal with quasistatic thermoviscoelastic problems.