Nanocones could be key to making inexpensive solar cells

first_img Explore further (Phys.org) — One of the biggest challenges facing the silicon photovoltaic industry is making solar cells that are economically viable. To meet this goal, the module cost, which is currently about $1/watt, needs to be decreased to just half that. Much of this cost comes from the silicon material and the expensive fabrication processes often used. In a new study, a team of scientists and engineers has demonstrated that a hybrid solar cell covered in silicon nanocones and a conductive organic polymer can address both cost-cutting areas while providing excellent performance. Citation: Nanocones could be key to making inexpensive solar cells (2012, June 5) retrieved 18 August 2019 from https://phys.org/news/2012-06-nanocones-key-inexpensive-solar-cells.html USC team develops promising polymer for solar cells Journal information: Nano Letters Copyright 2012 Phys.org All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.center_img More information: Sangmoo Jeong, et al. “Hybrid Silicon Nanocone-Polymer Solar Cells.” Nano Letters. DOI: 10.1021/nl300713x (a) Fabrication process of the solar cells, in which silicon nanocones are coated with a polymer. (b), (c), and (d) show scanning electron microscope images of the nanocones after each step. Image credit: Jeong, et al. ©2012 American Chemical Society This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. The researchers, led by Professor Yi Cui and Professor Michael D. McGehee from Stanford University, have published their study in a recent issue of Nano Letters.The hybrid solar cells’ use of nanoscale texturing has two advantages: it improves light absorption and reduces the amount of silicon material needed. Previous nanoscale texturing of solar cells has involved nanowires, nanodomes, and other structures. Here, the researchers found that a nanocone structure with an aspect ratio (height/diameter of a nanocone) of around one provides an optimal shape for light absorption enhancement because it enables both good antireflection (for short wavelengths of light) and light scattering (for long wavelengths). In previous designs using nanoscale texturing, the space between structures has normally been too small to be filled with polymer, so a full second layer is required. But the tapered nanocone structure demonstrated here allows for the polymer to be coated in the open spaces, eliminating the need for other materials. By forming this nanocone/polymer hybrid structure with a simple, low-temperature method, processing costs are also reduced.After testing the solar cell and making some improvements, the researchers produced a device with an efficiency of 11.1%, which is the highest among hybrid silicon/organic solar cells to date. In addition, the short-circuit current density, which indicates the largest current that the solar cell can generate, is only slightly lower than the world record for a monocrystalline silicon solar cell, and very close to the theoretical limit. Due to the hybrid silicon nanocone-polymer solar cells’ good performance and inexpensive processing, the researchers predict that they could one day be used as economically viable photovoltaic devices.last_img read more

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Graphene quantum dot flash memories look promising for data storage

first_img © 2014 Phys.org Citation: Graphene quantum dot flash memories look promising for data storage (2014, June 18) retrieved 18 August 2019 from https://phys.org/news/2014-06-graphene-quantum-dot-memories-storage.html Journal information: Nanotechnology (a) Schematic diagram and (b) image of a graphene quantum dot flash memory. Charge storage in discrete charge traps, such as graphene quantum dots, offers the potential for high-density data storage. Credit: Joo, et al. ©2014 IOP Publishing Resonant energy transfer from quantum dots to graphene (Phys.org) —Today’s commercial flash memories usually store data as electric charge in polysilicon layers. Because polysilicon is a single continuous material, defects in the material can interfere with the desired charge movement, which can limit data retention and density.center_img Explore further More information: Soong Sin Joo, et al. “Graphene-quantum-dot nonvolatile charge-trap flash memories.” Nanotechnology 25 (2014) 255203 (6pp). DOI: 10.1088/0957-4484/25/25/255203 To overcome this problem, researchers have recently been working on storing charge in discrete charge traps, such as nanocrystals, instead of polysilicon layers. Since discrete charge trap materials have the advantage of preventing unwanted charge movement as a result of their lower sensitivity to local defects, they offer the potential for high-density flash memories.Now in a new study, scientists have used graphene quantum dots instead of nanocrystals as the discrete charge trap material. The researchers, Soong Sin Joo, et al., at Kyung Hee University and Samsung Electronics, both in Yongin, South Korea, have published their paper on graphene quantum dot flash memories in a recent issue of Nanotechnology.Although graphene in general is widely known as an attractive material for next-generation electronics and photonics because of its unique properties, the development of graphene memory devices is still at an early stage. Graphene quantum dots in particular are very new materials. As bits of graphene extracted from bulk carbon, graphene quantum dots can be engineered with specific electronic and optical properties for different purposes.Here, the researchers prepared graphene quantum dots of three different sizes (6, 12, and 27 nm diameters) between silicon dioxide layers. The researchers found that the memory properties of the dots differ depending on their sizes. For instance, while the 12-nm dots exhibit the highest program speed, the 27-nm dots exhibit the highest erase speed, as well as the highest stability.”This is the first report of charge-trap flash nonvolatile memories made by employing structurally characterized graphene quantum dots, even though their nonvolatile memory properties are currently below the commercial standard,” coauthor Suk-Ho Choi at Kyung Hee University told Phys.org. “Actually, this is first successful application of graphene quantum dots in practical devices, including electronic and optical devices, as far as I know, even though there are many reports on physical and chemical characterizations of graphene quantum dots.”As flash memory devices in their early stages of development, the graphene quantum dot memories demonstrate a promising performance, with an electron density comparable to that of memory devices based on semiconductor and metal nanocrystals. The researchers hope that future improvements to the devices will lead to enhanced performance and new applications.”If flexible dielectrics (insulators) are used instead of silicon dioxides as tunnel and control barriers on plastic substrates, then they can be used in flexible (or wearable) electronic devices,” Choi said. “Metal nanoparticles also offer several advantages similar to graphene quantum dots, such as higher density of states, flexibility in choosing the work function, etc., for charge-trap flash nonvolatile memories, but may potentially degrade the device performance due to their thermal instabilities and are not useful for transparent and flexible electronics and photonics.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Picoscale precision though ultrathin film piezoelectricity

first_imgFig. 1. Schematic illustration of local characterization of in-plane piezoelectricity and vertical piezoelectricity. In-plane piezoelectricity (piezo) (d11, d22) of ultrathin materials is the planar electromechanical couple behavior, where the applied stress and produced piezoelectric potential are located at the in-plane of exposed lattice plane. Vertical piezoelectricity (d33) focus on electromechanical interaction occurred in the vertical axis, which is perpendicular to the surface of materials. The high-precision deformation actuator can be implemented using accurate positioning of the materials surface by vertical inverse piezoelectricity. Credit: X. Wang, X. He, H. Zhu, L. Sun, W. Fu, X. Wang, L. C. Hoong, H. Wang, Q. Zeng, W. Zhao, J. Wei, Z. Jin, Z. Shen, J. Liu, T. Zhang, Z. Liu, Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films. Sci. Adv. 2, e1600209 (2016). Copyright © 2016 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). DOI:10.1126/sciadv.1600209. Citation: Picoscale precision though ultrathin film piezoelectricity (2016, August 10) retrieved 18 August 2019 from https://phys.org/news/2016-08-picoscale-precision-ultrathin-piezoelectricity.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Fig. 4. Noncontact SKFM and standard contact PFM investigation for CdS thin film. (A and B) Schematic illustration of SKFM (A) and PFM (B) measurements. (C) Band diagram of tip and sample when they are electrically separated (top graph) and electrically contacted (bottom graph). d, distance; VL, vacuum levels; q, electronic charge; Vc, contact potential difference. (D) Optical image of CdS thin films. (E and F) Topography (E) and phase (F) images observed by SKFM mode for the single CdS thin film marked in (D). (G to I) Corresponding potential mappings with tip voltages of 3, 6, and 9 V, respectively. Insets show histograms of the surface potential distributions. The CdS ultrathin film has a higher positive voltage (~0.9 V) than the substrate, demonstrating that a large amount of charges are accumulated at a CdS thin film after contact PFM scanning. (J) Amplitude images observed by contact PFM technology with tip voltages from 1 to 6 V, showing remarkable inverse piezoelectricity. (K) Average amplitude variations versus applied voltages calculated from (J). Error bars indicate 1 SD. Scale bars, 2 μm (E to J). The linearly fitted line shows that the measured piezoelectric coefficient deff is ~16.4 pm·V−1, whereas the vertical piezoelectric coefficient d33 is ~32.8 pm·V−1. Credit: X. Wang, X. He, H. Zhu, L. Sun, W. Fu, X. Wang, L. C. Hoong, H. Wang, Q. Zeng, W. Zhao, J. Wei, Z. Jin, Z. Shen, J. Liu, T. Zhang, Z. Liu, Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films. Sci. Adv. 2, e1600209 (2016). Copyright © 2016 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). DOI:10.1126/sciadv.1600209. Journal information: Science Advances Lastly – and reminiscent of the challenge in demonstrating d33 vertical piezoelectricity at the atomic scale using CdS thin films – the researchers had to determine the CdS film vertical piezoelectric coefficient with in situ scanning Kelvin force microscopy (SKFM) and single and dual AC resonance tracking piezoelectric force microscopy (DART-PFM). “The quality of ultrathin piezoelectric CdS is the key to obtaining a reliable vertical piezoelectric coefficient.” Liu notes. “Some characterization tools like Raman and photoluminescence spectroscopies can help us to identify the CdS sample and confirm its high quality. Also, because of the geometrical vibrations of the CdS samples, the atomic force microscopy characterization should be carefully carried out in order to make sure our conclusions are solid.” This required the researchers to examine many SKFM and DART-PFM samples using to reach a solid conclusion about vertical piezoelectric behavior in CdS ultrathin films. Prof. Zheng Liu discussed the paper that he, Dr. Ting Zhang and their colleagues published in Science Advances, describing a series of challenges they faced starting with using chemical vapor deposition to synthesize 2~3 nm cadmium sulfide (CdS) thin films. “The vertical piezoelectricity, or d33, is the key parameter in piezoelectric materials for the fabrication of actuators used to position objects with extreme accuracy – down to the atomic scale in a broad range of cutting-edge equipment such as atomic force microscopy and scanning tunneling microscopy,” Liu tells Phys.org. “Moreover, high-performance ultrathin piezoelectric materials are crucial for the constructing ultra-high resolution and flexible electromechanically coupled devices.”Prior to this study, Liu points out, only a few studies reported the synthesis of atomic thin piezoelectric materials by a wet chemical method, examples of which include CdS and cadmium selenide (CdSe) nanoplatelets. “It’s a significant challenge to produce high-quality and atom-thin piezoelectric materials,” he adds. “In this research, the main challenge in synthesizing ultrathin piezoelectric CdS films via chemical vapor deposition” (or CVD) “lays in the selection of precursors and how to optimize the reaction parameters, such as growing temperature and time.”The scientists were then faced with demonstrating d33 vertical piezoelectricity at the atomic scale using ultrathin cadmium sulfide thin films. “When the thickness of materials reaches the nanoscale level,” Liu explains, “it’s very difficult to verify the piezoelectric effect and determine its values because of the coupling effect from the substrate – and surface geometries may affect the measurements at atomic limits as well.” For example, he illustrates, sample surface roughness reaches tens of picometers, which is the same scale with the vertical electromechanical response for materials. Explore further Fig. 6. Simulation of vertical piezoelectricity and subatomic deformation actuator. (A) Three-dimensional image of potential drop on CdS film. (B) Scanning electron microscopy image of a conductive tip for PFM characterization. (C and D) Bottom and side views of stress distribution on CdS film. (E to G) Simulation for subatomic deformation actuator. Different potentials were applied to surface deformation curves (E), mappings (G), and vertical deformation (F) of CdS thin films. Credit: X. Wang, X. He, H. Zhu, L. Sun, W. Fu, X. Wang, L. C. Hoong, H. Wang, Q. Zeng, W. Zhao, J. Wei, Z. Jin, Z. Shen, J. Liu, T. Zhang, Z. Liu, Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films. Sci. Adv. 2, e1600209 (2016). Copyright © 2016 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). DOI:10.1126/sciadv.1600209. The researchers concluded that contact piezoresponse force microscopy (PFM) – which uses a conductive tip to apply a highly localized electric field that allows imaging and manipulation of piezoelectric ferroelectric materials – could significantly change the surface potential of a CdS ultrathin film by applying stress to its surface. “Typically, applying mechanical stress to a piezoelectric material will generate electric charge that accumulates at the surface of the material, which is how we identify the piezoelectric materials,” Liu tells Phys.org. “We therefore believe that this results from piezoelectric polarizations giving rise to a large piezoelectric potential, in turn leading to a remarkable spatial separation of electrons and holes.” In this case, electrons generated by the piezoelectric effect will be trapped into the silicon dioxide (SiO2) dielectric layers, while the holes will be trapped inside the crystal boundary of the CdS films. The scientists state that their work may pave a way to the synthesis of ultrathin lattice scale nanomaterials using CVD method, which is a low-cost method for producing high quality samples. In addition, Liu notes, the materials provided by their study will enable the high-integrated and multi-functional devices by simply coating or transferring the film to the device. “For actuator applications, our work will promote next generation actuators with extreme resolution for their potential use in characterization tools such as ultra-high resolution microscopy; for atom manipulation and fabrication; or potentially for the detection of ultra-low deformation in, for example, cold atom studies, verification of the gravitational inverse square law at short range, and even the detection of gravitational waves.”Moving forward, Liu says, the scientists will determine the relationship between the vertical piezoelectric coefficient d33 and the thickness of CdS at atomic scales. “Well also synthesize other piezoelectric, ferroelectric and layered piezoelectric/ferroelectric ultrathin materials, and explore their electromechanical properties.” Based on this material and micro/nano-manufacture technology, the researchers hope to design and fabricate next-generation actuators for accurate positioning of minute objects, such as nanoparticles at subatomic scales, using their novel materials.In addition, the large vertical piezoelectric coefficient d33 makes this material promising to construction of ultrathin and sensitive pressure sensors for detecting miniscule forces. If the low detection limit of sensor reaches to nanoscale levels, the device could monitor single biological cell migration. “Our study will inspire material scientists to hunt for other non-trivial ultrathin or layered piezoelectric or ferroelectric materials,” Liu tells Phys.org. “Engineers can employ our CdS ultrathin films to design and fabricate novel microelectromechanical systems,” or MEMS, “and nanoelectromechanical systems,” or NEMS, “with high-integration and multi-functionalities, and may benefit when developing cutting-edge scientific instruments. Furthermore,” he concludes, “novel and flexible consumer electronic devices can be developed based on our study.” Arranging polymer nanotubes in a vertical array enhances piezoelectric properties for acoustic sensors Piezoelectricity (aka the piezoelectric effect) occurs within certain materials – crystals (notably quartz), some ceramics, bone, DNA, and a number of proteins – when the application of mechanical stress or vibration generates electric charge or alternating current (AC) voltage, respectively. (Conversely, piezoelectric materials can vibrate when AC voltage is applied to them.) The piezoelectric effect has a significant range of uses, including sound production and detection, generation of high voltages and electronic frequencies, atomic resolution imaging technologies (e.g., scanning tunneling and atomic force microscopy), and actuators for highly accurate positioning of nanoscale objects – the last being crucial for fundamental research and industrial applications. That being said, subatomic scale positioning still presents a number of challenge. Recently, however, researchers at Nanyang Technological University, Singapore, Chinese Academy of Sciences, Suzhou, and Duke University, Durham demonstrated vertical piezoelectricity at the atomic scale (three to five space lattices) using ultrathin cadmium sulfide (CdS) films. The researchers determined a vertical piezoelectric coefficient (d33) three times that of bulk CdS using in situ scanning Kelvin force microscopy and single and dual ac resonance tracking piezoelectric force microscopy, leading them to conclude that their findings have a number of critical roles in the design of next-generation sensors and microelectromechanical devices. More information: X. Wang et al, Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films, Science Advances 01 Jul 2016, Vol. 2, no. 7, e1600209, doi:10.1126/sciadv.1600209 Liu comments that addressing these challenges required innovative techniques. “For the first time, we successfully synthesized high-quality atomic thin CdS films using CVD, and we demonstrated vertical piezoelectricity of these films at the atomic scale of 3~5 space lattices” (a space, or crystal, lattice being a periodically repeating two- or three-dimensional array of points or particles) “and observed the vertical piezoelectric domains. More importantly,” Liu continues, “our work shows an enhanced vertical piezoelectricity in CdS ultrathin films at a level three times larger than the CdS bulk counterpart, as well as higher than most of traditional piezoelectric materials.” These results imply non-trivial piezoelectric behavior at atomic limits for a certain class of materials – which has not yet been well explored – and inspires the search for two-dimensional free-standing layered piezoelectric materials that are only one atom thick. Liu points out that their findings shed light on the design of next-generation sensors, actuators and microelectromechanical devices, in that piezoelectric materials are the most important component for such devices. Specifically, he says that their findings provide the opportunity for next-generation sensors and microelectromechanical devices in three ways:Flexibility: Ultrathin piezoelectric material materials are naturally like two-dimensional materials in being flexible, allowing them to be conformably used for more complicated electromechanical devices. Miniaturization: Ultrathin piezoelectric material materials are a perfect candidate for the fabrication of reduced size, highly integrated devices, especially for mobile phone and wearable devices. Inspiration: The study’s results will inspire the development of other ultrathin piezoelectric materials, especially two-dimensional piezoelectric materials. Liu illustrates these points by listing potential examples of such devices – for example, atomically thin piezoelectric devices – and their applications. “For instance, using CdS ultrathin films, the most accurate probe or stage ever fabricated may be achievable, allowing researchers and engineers to manipulate atoms or position tips in atomic force, scanning electron and transmission electron microscopy. In other words, CdS ultrathin films will extend our capability to see and manipulate our world in an extreme way.” Of more importance, he adds, such ultrathin piezoelectric devices can be integrated into equipment like autocollimators and Michelson interferometers used in, for example, cold atom studies, the verification of the gravitational inverse square law at short range, and even the detection of gravitational waves.The study also reports the in situ measurement of the ultrathin CdS film vertical piezoelectric coefficient d33, determining the film coefficient to be approximately three times larger than that of bulk CdS. “This value is pretty big for atomically thin materials,” Liu explains. “It means that we can get a large voltage change when small pressure or deformation is applied. This makes the material a great candidate constructing sensitive and ultrathin mechanical sensors.” © 2016 Phys.org Fig. 3. Spectroscopic characterization of CdS thin film. (A) Energy (E) band structure in the vicinity of the Γ-point of the Brillouin zone, showing the photon emission process. (B and C) PL spectrum of CdS thin film from points i and ii marked in (C) with plus signs, showing strong band edge emission (506 nm) of CdS ultrathin film and defect-related emission (595 nm). (C) Optical image of CdS thin film with a rounded microparticle at its center. a.u., arbitrary units. (D and E) PL mapping at an emission of 514 nm with a different scale bar, demonstrating high uniformity and homogeneity of CdS thin films at the outside area. (F) PL mapping at the 595-nm emission, indicating that the defect-related emission only occurs at the thicker CdS microparticle. Credit: X. Wang, X. He, H. Zhu, L. Sun, W. Fu, X. Wang, L. C. Hoong, H. Wang, Q. Zeng, W. Zhao, J. Wei, Z. Jin, Z. Shen, J. Liu, T. Zhang, Z. Liu, Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films. Sci. Adv. 2, e1600209 (2016). Copyright © 2016 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). DOI:10.1126/sciadv.1600209.last_img read more

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Tropical bats found to use carotenoids for skin coloration

first_imgA Honduran white bat. Credit: Geoff Gallice/Wikipedia/CC BY 2.0 Carotenoids are deeply colored photosynthetic pigments produced in plants, which animals use to prevent oxidative damage and to color external tissues. However, because animals can’t synthesize their own carotenoids, they rely on plant dietary sources. Mammals, including humans, are particularly limited in this regard by comparison with other classes, which often have brightly colored external markings and patterns produced by carotenoids. By contrast with the brightly colored feathers and scales of birds, reptiles and fish, mammals have only small amounts of carotenoids in their skin and seemingly none in their hair.Humans particularly rely on photosynthetic carotenoids for their provitamin A value, their immunostimulatory functions and antioxidant properties. Carotenoids are more highly concentrated in internal tissues than the skin, particularly in the macula of the eye. After consumption, carotenoids are carried through the bloodstream by lipoproteins—read dietary fats—to target tissues. Humans are thus particularly dependent on consuming dietary fat to ensure the bioavailability of carotenoids, which makes the choice between 0 percent and full-fat Greek yogurt much easier (and more delicious).The white fruit bat’s skin is a distinctive yellow, and particularly noticeable in hairless external features of the ears and nose, the integument. The researchers used high-performance liquid chromatography in combination with time-of-flight mass spectrometry in order to determine the specific carotenoid expressed in the bat’s skin. They theorize that the bat’s dietary source for lutein is the red ripe fruit of the Ficus colubrinae fig tree. Notably, the lutein in the skin of the bats contains esters, while their hepatic luteins were not esterified, indicating the biological ability to esterify lutein. “Although the nutritional use of xanthophylls [like lutein] may require esters to be metabolized, the fact that bats are able to esterify them into their integument opens up interesting possibilities for improving the benefits of xanthophylls to human health,” the authors write.In their report, the authors also speculate on the adaptive advantage of the bat’s ability to esterify lutein in its skin. Esterified xanthophylls provide plants with stability, and the bats might receive some benefit from achieving longer-lasting skin coloration. For instance, the Honduran white fruit bat is highly social, congregating and roosting together; such gregarious behavior is highly linked with the development of distinctive visual cues like coloration for communication purposes. “Altogether,” the authors conclude, “these results call into question the commonly neglected role of vision in bat communication and suggest microbats may have evolved color traits despite constraints imposed by nocturnal habitats.” More information: Tropical bat as mammalian model for skin carotenoid metabolism. PNAS (2016) DOI: 10.1073/pnas.1609724113AbstractAnimals cannot synthesize carotenoid pigments de novo, and must consume them in their diet. Most mammals, including humans, are indiscriminate accumulators of carotenoids but inefficiently distribute them to some tissues and organs, such as skin. This limits the potential capacity of these organisms to benefit from the antioxidant and immunostimulatory functions that carotenoids fulfill. Indeed, to date, no mammal has been known to have evolved physiological mechanisms to incorporate and deposit carotenoids in the skin or hair, and mammals have therefore been assumed to rely entirely on other pigments such as melanins to color their integument. Here we use high-performance liquid chromatography (HPLC) in combination with time-of-flight mass spectrometry (HPLC-TOF/MS) to show that the frugivorous Honduran white bat Ectophylla alba colors its skin bright yellow with the deposition of the xanthophyll lutein. The Honduran white bat is thus a mammalian model that may help developing strategies to improve the assimilation of lutein in humans to avoid macular degeneration. This represents a change of paradigm in animal physiology showing that some mammals actually have the capacity to accumulate dietary carotenoids in the integument. In addition, we have also discovered that the majority of the lutein in the skin of Honduran white bats is present in esterified form with fatty acids, thereby permitting longer-lasting coloration and suggesting bright color traits may have an overlooked role in the visual communication of bats. Journal information: Proceedings of the National Academy of Sciences Explore further Citation: Tropical bats found to use carotenoids for skin coloration (2016, October 10) retrieved 18 August 2019 from https://phys.org/news/2016-10-tropical-carotenoids-skin.htmlcenter_img © 2016 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Breeding better broccoli (Phys.org)—In the pursuit of greater carotenoid bioavailability to ensure human health, researchers have sought other animal models of carotenoid function. Recently, a collaborative of biologists in Spain and Costa Rica published the results of a study in the Proceedings of the National Academy of Sciences demonstrating that frugivorous Honduran white bats color their skin with the deposition of the carotenoid lutein—the primary carotenoid for the preservation of the macula in human eyes. This is the first time a mammal has been shown to concentrate high levels of carotenoids in skin, and thus may provide a model for the understanding and enhancement of carotenoid function.last_img read more

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Why invest in Belarus

first_imgDirect access to the market of the Customs Union and Common Economic Space (Belarus, Russia, and Kazakhstan); abolition of internal customs barriers; completion of the formation of Common Economic Space; liberalization of foreign exchange transactions; the country’s geographical position; the intersection of rail and road routes, oil and gas pipelines, communication systems, water and air communications between the industrialized Western Europe and Asia are some of the reasons why one should invest in Belarus. Also Read – ‘Playing Jojo was emotionally exhausting’There is also political, social and economic stability. The country also has an abundance of skilled labour. The state relies on public-private partnership. A key advantage for investing in Belarus is reducing of the share of public sector and privatization of state property. This ensures efficient use of resources.For large strategic enterprises of Belarus refused to quick sale of state assets. National legislation provides for various forms of investor participation in the privatization process. The Investment Agreement with the Republic of Belarus provides investors with additional incentives and preferences. This allows the investor to establish additional safeguards to protect their capital and also get preferential treatment and incentives for the investment project.last_img read more

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Of melody and memories

first_imgRang-E-Khusro – a two-day concert showcasing the life and works of Hazrat Amir Khusro was organised by Sakshi and Siet at India Habitat Centre recently. The first of the two day programme of poetry and music showcased a jugalbandi – ashaar and sitar, where renowned Sitar Maestro, Sudeep Rai accompanied by Ustad Rashid Zafar Khan (Tabla) flawlessly executed a masterly performance enhancing and building on the Poetic Reflections by well known litterateur and poet, Nazim Naqvi.  Also Read – ‘Playing Jojo was emotionally exhausting’The magical blend of the spoken word, reflecting on Hazrat Amir Khusro’s work mingling with the speaking strains of the sitar was unimaginably beautiful and had the audience spellbound.The second day featured Kalaam-E-Khusro – a mesmerising sufi vocal by Ustad Shakeel Ahmed and Vaishali Rai accompanied by Ustad Salim Ahmed Khan (Tabla), Ustad Syed Rehman Khan (Sarangi) and Anees Ahmed (Keyboard) on the second day. The beautiful Sufi kalaam Piya Ghar Aaye… melodiously sung by Vaishali Rai  opened the evening.  Then came a virtual feast of Sufi kalaams  in Shakeel Ahmed’s solo and duet act, presenting mesmerizing Sufi songs in his unique style which included songs like ChhaapTilak.. and Dama Dum Mast Kalandar amongst others.  Also Read – Leslie doing new comedy special with NetflixShakeel Ahmed treated the audience to the delectable farsee Amadabaqatl e man as also the khadi boli song Kahe ko byahi bides, exhibiting Hazrat Amir Khusro’s ease and mastery over these languages. Ahmed transported his listeners into Amir Khusro’s world of universal emotions, humanity and love. It was amazing to see such a houseful overflowing audience on two of the coldest and most foggy December nights making a perfect weekend for Delhiites.last_img read more

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Elusive tiger found dead inside Baghghora forest

first_imgKolkata: The Royal Bengal tiger which was spotted by the local villagers inside the forest areas of West Midnapore, Jhargram and Bankura on several occasions since early March, was found dead inside Baghghora forest, around 25 Km away from Lalgarh in Jhargram district.It was first spotted on March 2 by a camera which was installed in Lalgarh forest. Despite several attempts by the state forest department it could not be captured in the past one-and-a-half month. Also Read – Heavy rain hits traffic, flightsA senior official of the state forest department has said the tiger was found dead with various injury marks on its body. The reason of its death is yet to be confirmed by the department after the autopsy is done.”We heard that several injury marks were there on its body indicating that it might have been killed by local tribes. After post-mortem, we can confirm how the big cat was killed,” a senior forest department official added.He also said the local villagers essentially the tribes who go for hunting during this time of the year to celebrate their hunting festival were asked not to go into the forest as animals might prove to be fatal. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedIt was alleged that those taking part in the hunting festival might have killed the tiger as a spear was found stuck in the throat of the animal when its carcass was removed by the forest department officials. Forest officials had earlier said the tiger might have sneaked into the forest from Simlipal reserve in neighbouring Odisha.The forest department officials and police faced difficulties to remove the animal from the area as hundreds of villagers had gathered around the scene. Questions have been raised on why the forest department officials allowed the local villagers to conduct the hunting festival after pugmarks were found two days ago near Lalgarh. The forest department took several steps including the use of drones to detect the presence of the tiger. A few days ago, the tiger was spotted by the villagers who tried to capture the animal by the help of a huge net. The tiger managed to flee before the forest officials reached the spot. The carcass of the animal was taken to Midnapore for post mortem.It is an unfortunate incident and a sad day for Bengal as well. Forest officials had put in best efforts to catch it but they failed. There was always a threat to the tiger as it was straying in the villages, adjoining to the forests, said former Atanu Raha, former Principal Chief Conservator of Forests.”Since presence of the tiger was confirmed in Lalgarh forest, our men had tried their best to catch the big cat. But unfortunately, we failed to rescue it alive,” state forest minister Binay Krishna Burman.last_img read more

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SMST of IIT KGP to launch new programmes

first_imgKolkata: The School of Medical Science and Technology of IIT Kharagpur will launch new programmes from the upcoming academic session, a statement issued by the institute said today. The objective is to simultaneously train students and researchers on engineering and medical science, the statement said.The new courses will also include a 2-year M Tech in Biomedical Engineering.The school already runs a 3-year Masters in Medical Science and Technology, a unique programme of its kind with MBBS doctors being admitted in the domain of medical technology. Also Read – Heavy rain hits traffic, flightsThere will also be a joint MSc-PhD programme with the Tata Medical Center, Kolkata from the coming academic session in the areas of molecular medical microbiology, nuclear medicine and medical physics.The head of the School of Medical Science and Technology, IIT Kharagpur, Prof Suman Chakraborty said, “These programmes would bridge the gap among medicine, biological sciences and engineering with a road map to develop world-class scientists.” IIT KGP is also in the process of launching a 400-bed super speciality hospital which is expected to be operational by 2019.last_img read more

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Two girls found dead on railway tracks near Uluberia

first_imgKolkata: Mystery shrouds the death of two girls whose bodies were found on the railway tracks near Uluberia station on late Saturday night.Police are yet to confirm whether the victims had committed suicide by throwing themselves in front of a running train or there was any foul play behind the incident. According to circumstantial evidence, the investigators suspect that the victims might have committed suicide by jumping before a train. The exact cause is yet to be ascertained by the police. Some locals spotted two bodies lying on the railway tracks near Dompara crossing at around 10.30 pm on Saturday and they reported the matter to the railway police. They rushed to the spot and recovered the bodies. Two bags were found on the spot, which might belong to those two. According to a preliminary investigation, police suspect that the victims might have been friends who had decided to end their lives. No suicide note was, however, found from their bags. The cause behind taking this drastic step is yet to be ascertained by the police. Also Read – Heavy rain hits traffic, flightsA local told police that some of his friends went there with an intension to sit near the railway tracks when they spotted the two bodies and reported the matter to the railway police. After reaching the spot, the railway police officers found that the victims were already dead and there were multiple injury marks on their bodies. Police have sent the bodies for post-mortem. Police have started a probe to ascertain the identity of both the victims. All the nearby police stations have been informed.last_img read more

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Road rage hits attendance at Maruti factory

first_imgWorker attendance at Maruti Suzuki India Ltd here has been affected following an incident of road rage involving some of the employees and nearby villagers.A police complaint has been filed against more than 30 Maruti Suzuki workers employed at the company’s Manesar plant, a union leader said here on Tuesday.These workers were returning home in a company bus on Friday when the vehicle hit a car in Aliar village. “After heated arguments, the workers thrashed my 38-year-old brother very badly. He suffered fractures,” Jaiprakash, a resident of the village, said in his police complaint. Kuldeep Janghu, a Maruti union leader, said that some villagers had pledged to avenge the attack on the villager. “Some of our worried workers are not coming to work. The situation may turn grim if action is not taken on time,” Janghu said.last_img read more

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