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Author(s):  
Henja-Niniane Wehmann ◽  
Thomas Engels ◽  
Fritz-Olaf Lehmann

Wing damage attenuates aerial performance in many flying animals such as birds, bats and insects. Especially insect wings are fragile and light in order to reduce inertial power requirements for flight at elevated wing flapping frequencies. There is a continuing debate on the factors causing wing damage in insects including collisions with objects, mechanical stress during flight activity, and aging. This experimental study is engaged with the reasons and significance of wing damage for flight in the house fly Musca domestica. We determined natural wing area loss under two housing conditions and recorded flight activity and flight ability throughout the animals’ lifetime. Our data show that wing damage occurs on average after 6 h of flight, is sex-specific, and depends on housing conditions. Statistical tests show that both physiological age and flight activity have similar significance as predictors for wing damage. Tests on freely flying flies showed that minimum wing area for active flight is approximately 10-34% below the initial area and requires a left-right wing area asymmetry of less than approximately 25%. Our findings broadly confirm predictions from simple aerodynamic theory based on mean wing velocity and area, and are also consistent with previous wing damage measurements in other insect species.


2021 ◽  
Vol 13 (22) ◽  
pp. 4504
Author(s):  
Jinyu Bao ◽  
Xiaoling Zhang ◽  
Tianwen Zhang ◽  
Jun Shi ◽  
Shunjun Wei

Video synthetic aperture radar (Video-SAR) allows continuous and intuitive observation and is widely used for radar moving target tracking. The shadow of a moving target has the characteristics of stable scattering and no location shift, making moving target tracking using shadows a hot topic. However, the existing techniques mainly rely on the appearance of targets, which is impractical and costly, especially for tracking targets of interest (TOIs) with high diversity and arbitrariness. Therefore, to solve this problem, we propose a novel guided anchor Siamese network (GASN) dedicated to arbitrary TOI tracking in Video-SAR. First, GASN searches for matching areas in the subsequent frames with the initial area of the TOI in the first frame are conducted, returning the most similar area using a matching function, which is learned from general training without TOI-related data. With the learned matching function, GASN can be used to track arbitrary TOIs. Moreover, we also constructed a guided anchor subnetwork, referred to as GA-SubNet, which employs the prior information of the first frame and generates sparse anchors of the same shape as the TOIs. The number of unnecessary anchors is therefore reduced to suppress false alarms. Our method was evaluated on simulated and real Video-SAR data. The experimental results demonstrated that GASN outperforms state-of-the-art methods, including two types of traditional tracking methods (MOSSE and KCF) and two types of modern deep learning techniques (Siamese-FC and Siamese-RPN). We also conducted an ablation experiment to demonstrate the effectiveness of GA-SubNet.


2021 ◽  
Vol 880 (1) ◽  
pp. 012030
Author(s):  
N Suryaningsih ◽  
A Prasetyowati ◽  
F Busalim

Abstract Fires that occur naturally in the forest can cause uncontrolled fires due to the rapid spread of heat. This research is focused on the observation land in the Puncak Besar area of Pacet in Pengalengan District, Indonesia, where the area of land burned is approximately 100 hectares. The early warning system that was built in this study uses a range widening method. This method consists of 1 sector that functions to detect heat and initial gas that occurs in the remote area. The initial area of the hotspot is usually not detected by the forest operator. After testing the sensor performance on this device, the fire sensor can detect hotspots with an average range of 440 cm. The width of the detection angle using a shield can reach a range of - 45° to 45° and the wide angle of detection of a fire without a shield can reach a range of -90° to 90°. While the communication system on this device uses the GPRS/GSM module to send data to the Android application as a monitoring system. By using this early forest fire detection system, forest operators can monitor the starting point of a fire in remote areas around the forest and minimize the spread of fire points as one solution to overcome the wider spread of forest fires.


Author(s):  
E. P. Krivoshchekov ◽  
E. B. Elshin ◽  
G. S. Alyapyshev ◽  
A. V. Poseryaev

The main goal of this study was to improve the results of therapy in patients with chronic wounds on the foot in diabetics (I-II degree according to Wagner's classification) using histoequivalent bioplastic material «G-derm».Materials and methods. The study included 72 patients. The comparison group included 35 patients who underwent standard treatment with hydrocolloid dressings. The main group consisted of 37 patients. For them, in addition to standard treatment, the histoequivalent-bioplastic material «G-derm» was used. The patients' condition was assessed in dynamics on the 1st, 10th, 30th days from the start of treatment.Results. By the 30th day, the complete epithelialization was registered in 12 (16.7%) patients. The main group included 8 (21.6%) cases, and the control group – 4 (11.4%). The unsatisfactory epithelialization (healing less than a quarter of the initial area) by the 30th day of treatment was in 14 (19.4%) patients: in the main group – in 4 (10.9%) patients, in the comparison group – in 10 (28.5%) of patients. The remaining 25 (67.6%) patients in the main group and 21 (60%) participants in the comparison group had satisfactory epithelialization results by the 30th day of treatment.Conclusion. The results of this study show the effectiveness of using histoequivalent bioplastic material G-derm in local treatment of chronic wounds in patients with neuropathic diabetes in combination with standard therapies.The use of histoequivalent-bioplastic material in patients with diabetes leads to faster regeneration of the wound as well as increases the cases of complete epithelialization. 


2021 ◽  
Vol 12 (2) ◽  
pp. 433-445
Author(s):  
Mesti Nadya ◽  
◽  
Yudy Surya Irawan ◽  
Moch. Agus Choiron

Welding is one of the metal joining processes in manufacturing. CDFW (continuous drive friction welding) is a welding process to join two workpieces by applying pressure at one end of the object and rotating another one where the friction action applies at interface. The purpose of this study is to study temperature distribution on the surface of the welding area and the heat-affected zone represented by a fully plasticized zone (Zpl) and to get an insight of a friction welding process. The variables of CDFW used were double chamfer angle, upset pressure, and burn off length. The initial area of friction was equal that is at a diameter of 14 mm. The method of modeling the CDFW friction welding is via computer simulations using ANSYS 18.1 software. This research uses aluminum material type Al6061. The Taguchi method was applied in designing the simulations. In this modeling, the model with the double chamfer of 15 °, the upset pressure of 120 MPa, and the burn-off length of 9 mm has a small ZPl area of 10.256 mm2. Whilst the specimen model, with a double chamfer angle of 45 °, the upset pressure of 240 MPa, and the burn-off length of 7 mm has a large Zpl area of 56.55mm2. The area of a narrow fully plasticized area caused by small chamfer angle and an upset pressure of 240 MPa. The area of fully plasticized zone shows how much material can be integrated during the friction welding process and how much strength of the weld metal. The model with the chamfer angle of 15 º, the upset pressure of 240 MPa, and the burn-off length of 9 mm has the widest temperature distribution and the highest maximum temperature. Meanwhile, the model with the chamfer angle of 30º, the upset pressure of 120 MPa, and the burn-off length of 9 mm has the narrowest temperature distribution and the lowest maximum temperature. The smaller chamfer angle increased upset pressure and burn-off length result in the wider temperature distribution, higher maximum temperature, and smaller Zpl.


2021 ◽  
Vol 66 (1) ◽  
pp. 21-47
Author(s):  
J. O. Takhirov ◽  
◽  
Z. K. Djumanazarova ◽  

We investigate an epidemic non-linear reaction-diffusion system with two free boundaries. A free boundary is introduced to describe the expanding front of the infectious environment. A priori estimates of the required functions are established, which are necessary for the correctness and global solvability of the problem. We get sufficient conditions for the spread or disappearance of the disease. It has been proven that with a base reproductive number the disease disappears in the long term if the initial values and the initial area are sufficiently small.


Author(s):  
Liliada G. Silva ◽  
Amanda V. Albuquerque ◽  
Flávia C. M. Pinto ◽  
Rafaela S. Ferraz-Carvalho ◽  
José L. A. Aguiar ◽  
...  

AbstractChronic venous ulcers (CVU) of the lower limbs (LL) are common and cause psychological changes and significant social impact, as they make the patient susceptible to pain, absence from work and social bonds. Some materials are suggested as dressings for the treatment of CVU, but they are expensive and are generally not available for use in public health services. To evaluate the efficacy of the treatment for lower limbs (LL) chronic venous ulcer (CVU) using bacterial cellulose (BC), gel and multi-perforated film associated. A randomized controlled clinical-intervention study was performed among participants with LL CVU, divided into two groups: experimental (EG), treated with BC wound dressing and control (CG), treated with a cellulose acetate mesh impregnated with essential fatty acids (Rayon®). The participants were followed for 180 days, evaluated according to the MEASURE methodology. Thirty-nine patients were treated, 20 from the EG and 19 from the CG. In both groups, the wound area decreased significantly (p < 0.001), the healing rate was similar to the CG. The mean number of dressing changes in the SG was 18.33 ± 11.78, while in the CG it was 55.24 ± 25.81, p < 0.001. The healing dressing of bacterial cellulose, gel and associated film, when stimulating the epithelization of the lesions, showed a significant reduction in the initial area, with a percentage of cure similar to the Rayon® coverage. In addition to requiring less direct manipulation of ulcers.


2021 ◽  
Vol 6 (2) ◽  
pp. p1
Author(s):  
Assem Najat ◽  
Elharrani Hanae ◽  
El Haouari Mohammed ◽  
El Hafid Latifa ◽  
Chaaouan Jamal

The Tazekka National Park, created in 1950 on an initial area of 680 hectares, located in the mountain range of the Eastern, Middle Atlas, offers a great variety in terms of the landscape and the diversity of forest populations. However, studies have reported that the park’s biodiversity is threatened due to anthropogenic and climatic factors. The aim of this work is to carry out a comparative study concerning the influence of climate change during the years 1985, 2007 and 2018 on the distribution of plant species in different stations of the Tazekka National Park (Ras al ma, Bab Boudir, Bab Azhar and Jbel Tazekka).To carry out this work, several field trips were carried out. The results obtained in the form of GIS using the ArcGis 10.4.1 software have shown that climate change significantly influences the plant biodiversity of the Park. It is necessary to find assessment, monitoring and management strategies for these climate risks in order to preserve phytobiodiversity.


2021 ◽  
Vol 31 ◽  
pp. 00036
Author(s):  
Martin Schletterer ◽  
Brigitte Kurz ◽  
Alexandra Schönegger ◽  
Gregory Egger ◽  
Klaus Feistmantl

Translocations are applied in the context of infrastructure projects to preserve certain vegetation types. Within the EIA of a large hydropower project in the Austrian Alps, manifold mitigation measures were defined. Among those, the transplantation of about 1.4 ha Carex-fen at an altitude of about 2000 m was defined. One year before the start of the construction works in 2021, basic infrastructure (roads) was established and different ecological measures were undertaken, e.g. translocation of amphibians to newly constructed habitats as well as the transplantation of the Carex-fen. The turf was cut from the initial area with an adjusted excavator shovel, delivered to a wheel loader which brought each single turf immediately to the target area, where another excavator mounted the turf in a pre-arranged area. At the donor site more than ½ of the area was based on wet gley, while especially areas in the vicinity of the river were based on fluvial gravel. With the 30 to 70 cm thick turfs also animals, e.g. Odonata, were transferred. Before the translocation a monitoring of the donor sites was carried out. The monitoring concept foresees a detailed monitoring of the newly established sites for 10 years. Herein we provide insights in the applied technology and summarize first results of the monitoring. Overall, our project is unique regarding the vegetation type, the technology, the size and the intensity of monitoring.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5323
Author(s):  
Peter Sivák ◽  
Peter Frankovský ◽  
Ingrid Delyová ◽  
Jozef Bocko ◽  
Ján Kostka ◽  
...  

In exact analyses of bodies in the elastic–plastic regime, the behavior of the material above critical stress values plays a key role. In addition, under cyclic stress, important phenomena to be taken into account are the various types of hardening and the design of the material or structure. In this process, it is important to define several groups of characteristics. These include, for instance, the initial area of plasticity or load which defines the interface between elastic and plastic deformation area. The characteristics also include the relevant law of plastic deformation which specifies the velocity direction of plastic deformation during plastic deformation. In the hardening condition, it is also important to determine the position, size and shape of the subsequent loading area. The elasto-plastic theory was used for the analysis of special compliant mechanisms that are applied for positioning of extremely precise members of the Compact Linear Collider (CLIC), e.g., cryomagnets, laser equipment, etc. Different types of deformation hardening were used to simulate the behavior of particular structural elements in the elastic–plastic regime. Obtained values of stresses and deformations may be used in further practical applications or as default values in other strain hardening model simulations.


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