86,929 research outputs found
The Effects of Wind Induced Conductor Motion on Accreted Atmospheric Ice
No full textGalloping of transmission lines creates some cyclic stresses in the conductor and accreted atmospheric ice covering the conductor, which may result in ice failure leading to shedding. Attempts have been made in this research to estimate these cyclic stresses and experimental tests have been conducted to study their effects on atmospheric ice. First, galloping of an
ice-covered conductor was simulated by appropriate modification of existing models for bare conductors submitted to galloping. Then, the results of simulation were applied as input for a new model developed using ABAQUS. Results show that the layers of atmospheric ice at the top and bottom of the conductor endure maximum stress. The results of experimental tests with increasing cyclic stress show that ice does not break during
galloping at wind velocities below 4.5 m/s. The tests under cyclic loads with constant amplitude reveal that the ice does not fail under stresses corresponding to wind speeds of 3 and 4 m/s, and
sometimes fails under stresses arising at a wind speed of 5 m/s
Molecular analysis of CIB4 gene and protein in Kermani sheep
No full textThe human calcium- and integrin-binding protein (CIB) family is composed of CIB1, CIB2, CIB3, and CIB4 proteins and the CIB4 gene affects fertility. Kermani sheep is one of the most important breeds of Iranian sheep breeds. The aim of this study was to analyze for the first time molecular characteristics of the CIB4 gene and protein in Kermani sheep. Different tissues were collected from the Kermani sheep and real time PCR was performed. The PCR products were sequenced, comparative analyses of the nucleotide sequences were performed, a phylogenetic tree was constructed, and different characteristics of CIB4 proteins were predicted. Real time PCR results showed that the CIB4 gene is expressed only in testis of Kermani sheep. The cDNA nucleotide sequence was identical with small tail Han sheep, cattle, goat, camel, horse, dog, mouse and human, respectively 100, 99, 99, 98, 98, 96, 96, and 96%. Hence, it can be suggested that the CIB4 gene plays a role in male fertility. Based on the phylogenetic analysis, sheep CIB4 gene has a close relationship with goat and cattle first, and then with camel and whale. Although we demonstrated that CIB4 is a testis-specific gene, expressed only in the testis and it interacts with other proteins, the mechanisms by which CIB4 expression is regulated need to be elucidated
Nanomaterials and scaffolds for tissue engineering and regenerative medicine
No full textTissue engineering and regenerative medicine have caused a revolution in biomedicine over the past decade; the fabrication of tissue substitutes in the laboratory is now possible by using various cells, biomaterial scaffolds, and bioactive molecules. With the advent of nanotechnology, it has become possible to manufacture tissue-engineered constructs with the ability to improve cellular functions and subsequently accelerate tissue healing. Nanoscale materials are currently being used in diverse tissue-engineering applications, including the fabrication of three-dimensional scaffolds and the delivery of therapeutic molecules and drugs. Moreover, the surface modification of tissue-engineered constructs by applying nano-topographies is recognized as an effective strategy to elicit desirable biological responses, including better cell attachment and proliferation. Similar to other new technologies, the health benefits and risks of nanotechnology should be carefully evaluated before its extensive use and regulations and guidelines are needed. In this chapter, we have tried to present briefly the current state and progress of nanotechnology-assisted tissue engineering and regenerative medicine in the biomedical setting
Neotrombicula kermani Kudryashova 1977
No full text<i>Neotrombicula kermani</i> Kudryashova, 1977 <p> <i>Neotrombicula kermani</i> Kudryashova, 1977: 52, fig. 4; Kudryashova <i>et al.</i> 1978: 130.</p> <p> <b>Diagnosis.</b> SIF = 7BS-B-3-3111.1000; fPp = B/B/BBB; fsp = 7.7.7; fCx = l.1.1; fSt = 2.2; fSc: PL> AL> AM; fD = 2H- 8-10-8 (9)-6-6(4)-2(4); DS = 42–43; VS = 47–49; NDV = 91–92; Ip = 969–1005; eyes 2 + 2; f 1 anterior to S 1; f 2 posterior to S 2. Measurements of type series (Kudryashova <i>et al.</i> 1978): AW 76–81, PW 95–104, SB 34–36, ASB 34–36, PSB 28–32, SD 62–67, AP 31–34, AM 39–42, AL 48, PL 62–73, S 81, H 64–73, D min 42–50, D max 56–62, V min 31, V max 50–53, pa 333–342, pm 294–305, pp 339–361. Measurements of holotype: AW 79, PW 99, SB 34, ASB 36, PSB 32, SD 68, P-PL 29, AP 33, AM 40, AL 46, PL 65, H 71, D min 52, D max 65, V min 34, V max 52, pa 297, pm 247, pp 315, Ip 859.</p> <p> <b>Type material examined.</b> Holotype larva (ZMMU Tdt-54, I-146-4481) from <i>Meriones persicus</i>, Kerman, 2220 m a.s.l., 11 December 1970, coll. V.M. Neronov.</p> <p> <b>Host.</b> <i>Meriones persicus</i>.</p> <p> <b>Distribution.</b> Iran (Kerman).</p>Published as part of <i>Stekolnikov, Alexandr A., Saboori, Alireza, Shamsi, Mohsen & Hakimitabar, Masoud, 2019, Chigger mites (Acariformes: Trombiculidae) of Iran, pp. 1-66 in Zootaxa 4549 (1)</i> on page 48, DOI: 10.11646/zootaxa.4549.1.1, <a href="http://zenodo.org/record/2584949">http://zenodo.org/record/2584949</a>
Hydroxyapatite (HAp) nanoparticles: Promises in cancer diagnosis and therapy
No full textHydroxyapatite (HAp) nanoparticles have recently achieved a unique position in cancer diagnosis and therapy (theranostics). In vitro experiments have shown that HAp nanoparticles can enter tumor cells and cause programmed cell death (apoptosis). To improve the anticancer effects of HAp nanoparticles, bioengineers and biomedical scientists incorporate particular elements (e.g., iron (Fe)) into theranostic HAp nanoparticles. Accordingly, HAp nanoparticles can be employed in different cancer therapy approaches like photothermal therapy and photodynamic therapy, either alone or in combination with other materials (e.g., biopolymers). Moreover, HAp nanoparticles can serve as suitable vectors for targeted delivery of anticancer chemicals and drugs. Adding some elements, such as gadolinium and europium, to the HAp composition makes it a suitable imaging agent for bio-imaging applications like magnetic resonance imaging. Various surface modifications can be applied to improve the biocompatibility of HAp nanoparticles and prevent their aggregation. In addition, targeted therapy seems possible with HAp nanoparticles having the surface modified with specific ligands (e.g., anti-Herceptin antibody). In conclusion, HAp nanoparticles are showing great promise in cancer theranostic strategies; however, doing animal and clinical trials is suggested as a key step forward to take benefit from these stunning materials
Power sharing model for energy communities of buildings
No full textThe new concept of renewable energy communities introduced by the Revised European Directive on the promotion of renewable sources (2018/2001) has opened new possibilities for microgrids. In fact, it permits to enhance the value of the energy produced by renewable sources sharing it inside an 'energy community' and to increase the social welfare. In this article, the authors investigated about the actual legislation framework on energy communities at the European and Italian level, highlighting regulatory problems and barriers that are delaying their constitutions. The authors propose a 'power sharing model' (PSM), which is useful for energy communities based on the sharing of renewables and other energy services. The PSM is suitable for both the building level and larger communities. PSM has been analyzed through a case study that regards the preliminary study of a smart microgrid that should be realized in Campobasso, Italy, to connect buildings of the public administration. This scenario was investigated through a simulation conducted in Simulink environment where the control strategy was implemented, and the results were compared to a traditional configuration for renewable sources integration. The results highlight the adequacy of PSM for the energy community for the building's microgrids application
Implementation of SCADA systems for a real microgrid lab testbed
No full textConsidering the complexity of controller systems in and also managing a microgrid (MGs), using automation systems can be an effective step in increasing energy efficiency, high reliability, as well as economic and environmental issues. In order to achieve these goals, this paper presents a comprehensive testbed for control and energy management in MG lab project is called LAMBDA MG in Sapienza University of Rome. The MG is composed of several sources (Photovoltaic, Storage, Emergency Generator Set) a smart switchboard and loads (lights, HVAC, plugs). The control strategy consists of two different subnets: the first one is based on a distributed home and building electronic system (HBES) for the supervisory and control for energy and comfort goals and the second one based on a central PLC for the operation of the different sources in grid and island mode respect the grid. The two subnets are integrated in a common SCADA system able to provide a real time monitoring, alarm handling, human machine interfacing, event and data
A 'Power sharing model' (PSM) for buildings of the public administration
No full textThe new concept of renewable energy communities introduced by the Revised European Directive on the promotion of renewable sources (2018/2001) has opened new possibilities for microgrids. In fact, it permits to enhance the value of the energy produced by renewable sources sharing it inside an 'energy community' and to increase the social welfare. In the present paper, the authors investigated about the actual legislation framework on energy communities at European and Italian level, highlighting regulatory problems and barriers that are delaying their constitutions. The authors propose a 'power sharing model' (PSM) useful for energy communities and based on the sharing of renewables and other energy services. PSM is suitable both at building level and for larger communities. PSM has been analyzed through a case study that regards the preliminary study of a smart microgrid that should be realized in Campobasso, Italy, to connect buildings of the public administration. This scenario was investigated through a simulation conducted in Simulink environment were the control strategy was implemented, and the results were compared to a traditional configuration for renewable sources integration
Additive Manufacturing of Bioactive Glasses: Focus on Bone Tissue Engineering
No full textIn tissue engineering and regenerative medicine, bioactive glasses (BGs) offer many potential advantages. These inorganic substances belong to the bioceramics family and are traditionally produced in powder and granular formats via the sol-gel and melt-quenching synthesis routes. In order to mimic the native structure of human tissues, BGs should be fabricated into three-dimensional (3D) constructs (i.e., scaffolds). There are specific conventional fabrication methods for producing BG-based scaffolds (e.g., foam replication); however, they suffer from some critical limitations such as the lack of exact control on the pore dimension and distribution. In this regard, additive manufacturing (AM), also known as 3D printing, has emerged for the generation of precise and high-resolution BG-based scaffolds. Currently, 3D printing of BG-based scaffolds is performed by using a series of well-developed AM techniques, including direct 3D printing, selective laser sintering (SLS), robocasting, and stereolithography (SLA). In some methods, BGs are added to polymeric matrices and then introduced into the 3D printing machine as a raw material. In general, 3D-printed constructs exhibit important advantages over conventionally-fabricated tissue-engineering scaffolds in terms of reproducibility, scalability, architecture (e.g., controllable strut thickness, pore shape and size), and biomechanical properties. It is of significance that BGs can be simultaneously printed with mammalian cells (e.g., stem cells), known as 3D bioprinting. Still, some challenges (e.g., decreased cell viability) remain that should be addressed by conducting further research and proposing innovative solutions
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