Undesirable Areas Research Articles

Autonomous Steerable Ram-Air Type Load Parachute System Desıgn And Alternatıve Trajectory Algorıthm

The required supplies should be delivered by air to places that cannot be reached by land or sea. However, air resupply requires a runway on which the aircraft can land. In order to eliminate this need, the airdrop method is used. Airdrop is a commonly used replenishment method in both humanitarian aid operations and military operations where necessary. The most important limitations of airdrop replenishment are that the cargo may be affected by the wind and fall into undesirable areas and that the aircraft is vulnerable to enemy air defense systems. In today's cross-border operations, airdrops are necessary to ensure that troops can reach the supplies they need. GPS-guided, steerable parachutes can be used for high-altitude, long-distance airdrop by protecting the aircraft from enemy air defense weapons and preventing the payload from being blown away by the wind or into the hands of undesirable persons. In this study, the design of the system required by the Turkish Armed Forces is made, the command and control unit is created and the trajectory tracking algorithm is presented.

Portrait of intense communications within microfluidic neural networks

In vitro model networks could provide cellular models of physiological relevance to reproduce and investigate the basic function of neural circuits on a chip in the laboratory. Several tools and methods have been developed since the past decade to build neural networks on a chip; among them, microfluidic circuits appear to be a highly promising approach. One of the numerous advantages of this approach is that it preserves stable somatic and axonal compartments over time due to physical barriers that prevent the soma from exploring undesired areas and guide neurites along defined pathways. As a result, neuron compartments can be identified and isolated, and their interconnectivity can be modulated to build a topological neural network (NN). Here, we have assessed the extent to which the confinement imposed by the microfluidic environment can impact cell development and shape NN activity. Toward that aim, microelectrode arrays have enabled the monitoring of the short- and mid-term evolution of neuron activation over the culture period at specific locations in organized (microfluidic) and random (control) networks. In particular, we have assessed the spike and burst rate, as well as the correlations between the extracted spike trains over the first stages of maturation. This study enabled us to observe intense neurite communications that would have been weaker and more delayed within random networks; the spiking rate, burst and correlations being reinforced over time in terms of number and amplitude, exceeding the electrophysiological features of standard cultures. Beyond the enhanced detection efficiency that was expected from the microfluidic channels, the confinement of cells seems to reinforce neural communications and cell development throughout the network.

Facial morphology differences in monozygotic twins: a retrospective stereophotogrammetric study.

To assess soft tissue differences between monozygotic twins (MZ) for the total face and between facial regions using three-dimensional (3D) stereophotogrammetry and quantitative surface-based 3D deviation analyses. The study sample consisted of 14 untreated MZ twins (6 males, 8 females, mean age: 14.75 years) from the archive of Marmara University, Department of Orthodontics. The images were taken by the 3dMDface system, and 3dMDvultus software was used for removal of undesired areas and approximation of the images. Then, stereolithography (.stl) format images were superimposed using the best-fit algorithm using 3-matic software. The face was divided into facial thirds, and upper lip and lower lip + chin regions were created. For the comparison, 3D deviation analyses were performed, and a color map and histogram were created. The data were presented as mean deviation, root mean square (RMS), median, and interquartile range. Between the facial thirds, there was no significant difference in soft tissue differences for mean deviation. A statistically significant difference was found between the upper and lower face for the RMS value. For the comparison of upper lip and lower lip + chin region, the only significant difference was for the RMS. When the data were presented as median and interquartile range, there were no statistically significant differences between any facial regions. Lower facial third and lower lip + chin regions had the greatest differences within MZ twin pairs. The genetic and environmental influences might not be the same for different parts of the face.

Multi-objective optimization for inherently selective atomic layer deposition of zirconia on silicon and not on copper

Atomic layer deposition (ALD) deposits uniform, pinhole free metal or metal oxide films via a self-limiting surface reaction. Area-selective ALD allows selective deposition of these films on targeted areas. Other than using masking to prevent deposition on undesired areas of the substrate, the process parameters can be altered to achieve selectivity. However, determination of whether an ALD process is selective under the chosen reaction conditions requires rigorous experiments to be performed. ALD is a slow process and requires expensive organometallic complexes known as metal precursors. Simulation models built on the experimental data can eliminate the need for performing multiple experiments by predicting reaction conditions that promote selective growth thus saving time and cost. A little or no information was found in literature on models that can predict selectivity window of an ALD process by looking at process parameters. Our inhouse experimental data obtained from the inherently selective atomic layer deposition (ISALD) of zirconia on silicon and not on copper were used to build a simulation model that predicts selectivity of the ISALD process over a wide range of temperature. Multi-objective optimization algorithm was developed to find optimal process condition that can maximize the deposition rate on silicon while minimizing the same on copper. The theoretical framework is based on the equilibrium reached at the substrate surface after chemisorption of the precursor molecules. The chemisorption process is influenced by the interactions of the groups present in the precursor molecules and on the substrate surface. Universal Quasi-chemical Functional-group Activity Coefficient method for group contribution was used to quantify the interactions between different groups. Further, we show that the same group interaction parameters can be used with a different zirconium precursor having same functional groups to predict growth characteristics of zirconia on silicon under similar reaction conditions.

AAV11 enables efficient retrograde targeting of projection neurons and enhances astrocyte-directed transduction

Viral tracers that enable efficient retrograde labeling of projection neurons are powerful vehicles for structural and functional dissections of the neural circuit and for the treatment of brain diseases. Currently, some recombinant adeno-associated viruses (rAAVs) based on capsid engineering are widely used for retrograde tracing, but display undesirable brain area selectivity due to inefficient retrograde transduction in certain neural connections. Here we developed an easily editable toolkit to produce high titer AAV11 and demonstrated that it exhibits potent and stringent retrograde labeling of projection neurons in adult male wild-type or Cre transgenic mice. AAV11 can function as a powerful retrograde viral tracer complementary to AAV2-retro in multiple neural connections. In combination with fiber photometry, AAV11 can be used to monitor neuronal activities in the functional network by retrograde delivering calcium-sensitive indicator under the control of a neuron-specific promoter or the Cre-lox system. Furthermore, we showed that GfaABC1D promoter embedding AAV11 is superior to AAV8 and AAV5 in astrocytic tropism in vivo, combined with bidirectional multi-vector axoastrocytic labeling, AAV11 can be used to study neuron-astrocyte connection. Finally, we showed that AAV11 allows for analyzing circuit connectivity difference in the brains of the Alzheimer’s disease and control mice. These properties make AAV11 a promising tool for mapping and manipulating neural circuits and for gene therapy of some neurological and neurodegenerative disorders.

Damselflies (Coenagrionidae) have been avoiding leaf veins during oviposition for at least 52 million years

Plant-insect interactions can provide extremely valuable information for reconstructing the oviposition behavior. We have studied about 1350 endophytic egg traces of coenagrionid damselflies (Odonata: Zygoptera) from the Eocene, identifying triangular or drop-shaped scars associated with them. This study aims to determine the origin of these scars. Our behavioral study of about 1,800 endophytic eggs from recent coenagrionids indicates that these scars were caused by ovipositor incisions, but without egg insertion. The scar correlates (χ2-test) with leaf veins in both fossil and extant species. We infer that a female would detect the proximity of a leaf vein and avoid egg-laying, generating a scar that also fossilizes. For the first time, a scar produced by the ovipositor has been identified, indicating the existence of undesirable areas for oviposition. Accordingly, we recognize that Coenagrionidae damselflies (narrow-winged damselflies or pond damselflies) have been avoiding leaf veins for at least 52million years.

Fruiting phenology matters

Social Impact StatementIn the face of the unprecedented rate of climate change, understanding whether plant species can track favourable climatic conditions is an urgent challenge. Recent independent studies suggest that the timing of fruiting (fruiting phenology) can strongly affect future vegetation dynamics and composition via direct seed dispersal. With comprehensive datasets on fruiting phenology, researchers may predict the impact of climate on the future of forests. Nevertheless, long‐term, broad‐scale, and taxonomically comprehensive datasets of fruiting phenology are still lacking, leaving us unprepared to understand the consequences of climate change on entire floras. We urge stronger collaboration networks to assemble broader, longer, and more comprehensive fruiting phenology datasets.SummaryClimate change is altering species phenology but still with underrated consequences to their ecology and conservation. For example, the production of ripe fruits and the dispersal of their seeds by frugivores are likely critical for their ability to track suitable growing conditions under global warming. Specifically, recent independent studies suggested that migrant birds and mammals are important to facilitate plant spread towards higher (i.e., cooler) latitudes and higher elevations. Interestingly, these studies coincide that spring‐fruiting species will likely be particularly favoured, whereas autumn‐fruiting species might be largely dispersed to undesirable (i.e., even hotter) areas. These studies show that the timing of fruit production can have a critical impact on future forest composition as plant communities adapt to warmer, more extreme, and unpredictable climates. Unfortunately, comprehensive datasets on fruiting times are very scarce and often temporary, spatially, and taxonomically restricted (particularly when compared with flowering datasets), strongly hampering our capacity to predict the real impact of climate change on long‐term vegetation dynamics. Thus, we advocate for an urgent need for long‐term, broad‐scale, and taxonomically comprehensive datasets of fruiting phenology, and we point out some potential concrete steps towards this goal.

Ultrathin SU-8 membrane for highly efficient tunable cell patterning and massively parallel large biomolecular delivery.

Cell patterning is a powerful technique for the precise control and arrangement of cells, enabling detailed single-cell analysis with broad applications in therapeutics, diagnostics, and regenerative medicine. This study presents a novel and efficient technique that enables massively parallel high throughput cell patterning and precise delivery of small to large biomolecules into patterned cells. The innovative cell patterning device proposed in this study is a standalone, ultrathin 3D SU-8 micro-stencil membrane, with a thickness of 10 μm. It features an array of micro-holes ranging from 40 μm to 80 μm, spaced apart by 50 μm to 150 μm. By culturing cells on top of this SU-8 membrane, the technique achieves highly efficient cell patterns varying from single-cell to cell clusters on a Petri dish. Utilizing this technique, we have achieved a remarkable reproducible patterning efficiency for mouse fibroblast L929 (80.5%), human cervical SiHa (81%), and human neuroblastoma IMR32 (89.6%) with less than 1% defects in undesired areas. Single-cell patterning efficiency was observed to be highest at 75.8% for L929 cells. Additionally, we have demonstrated massively parallel high throughput uniform transfection of large biomolecules into live patterned cells by employing an array of titanium micro-rings (10 μm outer diameter, 3 μm inner diameter) activated through infrared light pulses. Successful delivery of a wide range of small to very large biomolecules, including propidium iodide (PI) dye (668.4 Da), dextran (3 kDa), siRNA (13.3 kDa), and β-galactosidase enzyme (465 kDa), was accomplished in cell patterns for various cancer cells. Notably, our platform achieved exceptional delivery efficiencies of 97% for small molecules like PI dye and 84% for the enzyme, with corresponding high cell viability of 100% and 90%, respectively. Furthermore, the compact and reusable SU-8-based membrane device facilitates highly efficient cell patterning, transfection, and cell viability, making it a promising tool for diagnostics and therapeutic applications.

Fast optimization of viscosities for frequency‐weighted damping of second‐order systems

AbstractWe consider frequency‐weighted damping optimization for vibrating systems described by a second‐order differential equation. The goal is to determine viscosity values such that eigenvalues are kept away from certain undesirable areas on the imaginary axis. To this end, we present two complementary techniques. First, we propose new frameworks using nonsmooth constrained optimization problems, whose solutions both damp undesirable frequency bands and maintain the stability of the system. These frameworks also allow us to weight, which frequency bands are the most important to damp. Second, we also propose a fast new eigensolver for the structured quadratic eigenvalue problems (QEPs) that appear in such vibrating systems. In order to be efficient, our new eigensolver exploits special properties of diagonal‐plus‐rank‐one (DPR1) complex symmetric matrices, which we leverage by showing how each QEP can be transformed into a short sequence of such linear eigenvalue problems. The result is an eigensolver that is substantially faster than standard techniques. By combining this new solver with our new optimization frameworks, we obtain our overall algorithm for fast computation of optimal viscosities. The efficiency and performance of our new approach are verified and illustrated on several numerical examples.

Soft template promoted microphase separation in anion exchange membrane of electrodialysis

This work reports a novel, effective, soft template strategy that can fabricate good-performance anion exchange membranes (AEMs) for electrodialysis application. Specifically, 1,2-ethanedisulfonic acid (EDA) is used as a small-molecule, soft template to promote microphase separation in multi-cation functionalized poly (2,6-dimethyl-1,4-phenylene oxide) membranes through electrostatic interaction between quaternary ammonium groups and sulfonic acid groups. The enhanced microphase separation has been confirmed by transmission electron microscopy (TEM) and small angle X-ray scattering studies. The prepared TPPO-2S-x membranes (where x represents the mass percent of EDA) were tested in the electrodialysis device for desalinating 0.1 M NaCl solution. Among them, the TPPO-2S-1 membrane gave the highest ED current efficiency (92.90 %), the lowest energy consumption (4.08 kWh kg−1), and the largest Cl− transport number (0.98); these performance results are better compared with those of the TPPO-2S-0 membrane (89.29 %, 4.39 kWh kg−1, and 0.98), which is not processed by soft template strategy. Although the TPPO-2S-4 and TPPO-2S-7 membrane show more obvious microphase separation than TPPO-2S-1, the current efficiencies of their ED devices are lower and the energy consumptions are higher due to their undesirable surface area resistance and chloride ion transport number. The investigation demonstrates that the soft template strategy is effective to improve membrane performance in ED devices.

An olfactory display for virtual reality glasses.

Olfaction has not been explored in virtual reality environments to the same extent as the visual and auditory senses. Much less research has been done with olfactory devices, and very few of them can be easily integrated into virtual reality applications. The inclusion of odor into virtual reality simulations using a chemical device involves challenges such as possible diffusion into undesired areas, slow dissipation, the definition of various parameters (e.g., concentration, frequency, and duration), and an appropriate software solution for controlling the diffusion of the odor. This paper aims to present a non-intrusive, mobile, low cost and wearable olfactory display, and a software service that allows the developer to easily create applications that include olfactory stimuli integrated with virtual reality headset glasses. We also present a case study conducted with 32 people to evaluate their satisfaction when using the olfactory display. Our findings indicate that our solution works as expected, producing odor properly and being easy to integrate to applications.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00530-022-00908-8.

Multimodal Locomotion and Active Targeted Thermal Control of Magnetic Agents for Biomedical Applications.

Magnetic microrobots can be miniaturized to a nanometric scale owing to their wireless actuation, thereby rendering them ideal for numerous biomedical applications. As a result, nowadays, there exist several mechano‐electromagnetic systems for their actuation. However, magnetic actuation is not sufficient for implementation in biomedical applications, and further functionalities such as imaging and heating are required. This study proposes a multimodal electromagnetic system comprised of three pairs of Helmholtz coils, a pair of Maxwell coils, and a high‐frequency solenoid to realize multimodal locomotion and heating control of magnetic microrobots. The system produces different configurations of magnetic fields that can generate magnetic forces and torques for the multimodal locomotion of magnetic microrobots, as well as generate magnetic traps that can control the locomotion of magnetic swarms. Furthermore, these magnetic fields are employed to control the magnetization of magnetic nanoparticles, affecting their magnetic relaxation mechanisms and diminishing their thermal properties. Thus, the system enables the control of the temperature increase of soft‐magnetic materials and selective heating of magnetic microrobots at different positions, while suppressing the heating properties of magnetic nanoparticles located at undesired areas.

Area selective deposition using alternate deposition and etch super-cycle strategies.

Area selective deposition (ASD) is a bottom-up process leading to a uniform deposition in only desired areas of a patterned substrate, avoiding the use of photolithography for patterning. However, whatever the strategy used to develop selective deposition by atomic layer deposition, there always comes a time when selectivity becomes defective and growth in undesired substrate areas must be corrected. This leads to the design of ASD by super-cycle alternating deposition and etch. Recent examples from the literature show a great diversity in the design of the etching step and indicate that the optimization of selective deposition by super-cycles is only possible through a careful optimization of the etching step parameters (chemistry, frequency, duration, etc.). In this paper, we discuss how to optimize this step and we show that different approaches can be developed to optimize the overall ASD process throughput, while simultaneously limiting process drift and contamination. We also show that complementary selective properties can prove a valuable leverage enabling ASD processes based on super-cycles, such as structure selective deposition, whereby a difference in thin film morphology in growth and non-growth areas can be smartly taken advantage of during the etching step.

Enhancing Gain for UWB Antennas Using FSS: A Systematic Review

This review paper combs through reports that have enhanced antenna gain for ultra-wideband (UWB) frequencies using frequency-selective surface (FSS) techniques. The FSS techniques found across the research landscape were mapped onto a taxonomy in order to determine the most effective method for improving antenna gain. Additionally, this study looked into the motivation behind using FSS as a reflector in UWB frequencies to obtain directional radiation. The FSS suits multiple applications due to its exceptional ability to minimize power loss in undesired transmission areas in the antenna, as well as to hinder the interference that may occur from undesirable and wasted radiation. An efficient way to obtain constant gain over a wide range of frequencies is also elaborated in this paper. Essentially, this paper offers viable prescription to enhance antenna gain for UWB applications. Methods: A comprehensive study was performed using several imminent keywords, such as “high gain using FSS”, “gain enhancement using FSS”, “high gain UWB antennas”, and “gain enhancement of UWB antennas”, in different modifications to retrieve all related articles from three primary engines: Web of Science (WoS), IEEE Xplore, and Science Direct. Results: The 41 papers identified after a comprehensive literature review were classified into two categories. The FSS single- and multi-layer reflectors were reported in 25 and 16 papers, respectively. New direction: An effective method is proposed for FSS miniaturization and for obtaining constant gain over UWB frequencies while maintaining the return loss at −10 dB. Conclusion: The use of FSS is indeed effective and viable for gain enhancement in UWB antennas. This systematic review unravels a vast range of opportunities for researchers to bridge the identified gaps.

An Efficient RRT Algorithm for Motion Planning of Live-Line Maintenance Robots

The application of robots to replace manual work in live-line working scenes can effectively guarantee the safety of personnel. To improve the operation efficiency and reduce the difficulties in operating a live-line working robot, this paper proposes a multi-DOF robot motion planning method based on RRT and extended algorithms. The planning results of traditional RRT and extended algorithms are random, and obtaining sub-optimal results requires a lot of calculations. In this study, a sparse offline tree filling the planning space are generated offline through the growing–withering method. In the process of expanding the tree, by removing small branches, the tree can fully wiring in the planning space with a small number of nodes. Optimize wiring through a large number of offline calculations, which can improve the progressive optimality of the algorithm. Through dynamic sampling and pruning, the growth of trees in undesired areas is reduced and undesired planning results are avoided. Based on the offline tree, this article introduces the method of online motion planning. Experiments show that this method can quickly complete the robot motion planning and obtain efficient and low-uncertainty paths.

Methodology for Highly Efficient Pump System Management

Maintaining pump operation in the best efficiency zone (BEZ) is one of the most important tasks of the control system. The main management tasks include detecting work outside the BEZ, preventing actions that may move the work point to undesirable areas, and regulating pumping parameters to keep work within the recommended limits. Thanks to the process control architecture of pump systems that use PLCs and programmable frequency converters, new algorithms can be implemented on these devices. This study provides suggestions for using sensor data, internal frequency converter parameters, or pump performance data from performance graphs for new control algorithms. For this purpose, the methodology of predictive control and performance monitoring were described. Pump operation outside BEZ and related phenomena were considered. The proposed algorithm for high-efficiency pump control in certain speed ranges were elaborated. Simulation of test runs of a pumping system relied on computer simulation tools modeling and software for VSD selection. Experimental tests were also introduced on a laboratory installation that simulates a pumping system.

Image stitching for fringe projection profilometry

There are many optical methods for extracting the geometric information of an object from an image. The structured light method based on digital fringe projection is widely employed. Sometimes the fringe patterns have some undesired invalid areas due to drastic surface profile changes of the tested object, or geometric discontinuities. In addition, a large projection angle affects the quality of the acquired data. These invalid areas may introduce difficulties for further processing. We propose to combine image fusion methods and a typical structured light system to alleviate the shadow problems created by a single projector.

View-dependent Projection Mapping Enhanced by Real Background

"Spatial augmented reality (SAR)" or "projection mapping" projects an image of a virtual object on the surface of a real object. A "view-dependent" display shows the virtual object with its correct appearance for an arbitrary viewer's position. If the virtual object and the real object have different shapes, the virtual object's image to project needs to be correctly distorted according to the viewer's position. Besides, the difference causes the real object's surface to have some empty areas onto which the virtual object is not projected. Such empty areas seriously degrade the viewer's feeling that the virtual object merges into the real world. We propose a method to eliminate undesired empty areas by projecting the real background behind the real object in a view-dependent way. Our method converts a real background's image captured by a fixed camera to an appropriate image for a viewer's position based on homography. This image conversion approximates the background's shape by a plane adjusted for an arbitrary viewer's position. The plane is determined by practical parameters interpolated on a 3D grid space. Consequently, the viewer does not feel the presence of the real object and feels the virtual object merging into the real world.

Large chest keloids treatment with expanded parasternal intercostal perforator flap

BackgroundChest keloids often converged into a large lesion on the chest in some patients. Such keloids often lead to obstacle to excision and reconstruction. We describe a surgical method for large chest keloids with expanded parasternal intercostal perforator flap (EPIPF).MethodsFifteen patients with chest keloid were treated with EPIPF in our department between August 2017 and Dec 2019. The surgical treatment was divided into two different phases. In the first phase, we implanted skin expanders into the layer under the deep fascia beside the keloids. The expander was expanded every week for about 3–4 months. In the second phase, the expander was removed, the keloid tissue was removed and an expanded perforator flap was then designed to cover the wound. Patients were followed-up after surgery. Complications after surgery were analyzed. Recurrence and the patients, satisfactory rate was recorded.ResultsOf the 15 patients, one patient complicated with undesirable small area wound healing. 11 were cured without scar hypertrophy or recurrence and four were partially cured with a small portion of scar hypertrophy. Eleven patients thought that the esthetic result was good (73.7%), and 4 patients thought the result was acceptable (26.7%). None patient was dissatisfied.ConclusionEPIPF are effective surgical method for managing large chest keloids. It can offer enough skin flap coverage for keloid wound resurfacing with stable blood supply to assure satisfactory results.Level of evidenceLevel IV, case series.

Ranging On-Demand Microwave Power Transfer in Real-Time

This letter presents a novel system for real-time ranging wireless power transfer (WPT) “on-demand.” This is obtained by duty-cycling a frequency diverse array (FDA) and by suitably choosing the time delay of the pulse. First, the theoretical design of the time- and frequency-dependent array is developed, and then it is applied to predict the ranging performances of a 16-element linear array. The simulations demonstrate the system's ability not only to dynamically select the area for energy focusing but also to reduce the energy intensity in undesired areas. The sharpness of this operation depends on the number of elements of the array. For validation purposes, a demonstrator has been implemented making use of the software-defined radio (SDR) Xilinx RFSoC ZCU111 to dynamically generate various radio signal excitations of the antenna array. To comply with the adopted SDR the operating frequency is 1.8 GHz and a four-element array is used. First measurements confirm the ranging capabilities of the proposed solution.