34 research outputs found
ΠΠ΅ΡΡΠΎ-Π΄ΠΈΠ·Π΅Π»ΡΠ½Π°Ρ ΡΠΈΡΡΠ΅ΠΌΠ° ΡΠ»Π΅ΠΊΡΡΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΡ ΠΏΠΎΡΠ΅Π»ΠΊΠ°
Π Π°Π±ΠΎΡΠ° Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½Π° Π½Π° ΡΠ΅ΡΠ΅Π½ΠΈΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΡΠ»Π΅ΠΊΡΡΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΡ ΠΎΡΠ΄Π°Π»Π΅Π½Π½ΡΡ
ΡΠ°ΠΉΠΎΠ½ΠΎΠ².
ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ Π³ΠΈΠ±ΡΠΈΠ΄Π½Π°Ρ Π²Π΅ΡΡΠΎ-Π΄ΠΈΠ·Π΅Π»ΡΠ½Π°Ρ ΡΠΈΡΡΠ΅ΠΌΠ° ΡΠ»Π΅ΠΊΡΡΠΎΡΠ½Π°Π±ΠΆΠ΅Π½ΠΈΡ, Π½Π°Ρ
ΠΎΠ΄ΡΡΠ°ΡΡΡ Π½Π° ΡΠ³Π΅ ΠΠ΅ΠΌΠ΅ΡΠΎΠ²ΡΠΊΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΠΈ Π½Π° Π²ΡΡΠΎΡΠ΅ 1260 ΠΌΠ΅ΡΡΠΎΠ². Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈΡΡ Π°Π½Π°Π»ΠΈΠ· ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Π² ΠΎΡΠΊΡΡΡΠΎΠΌ Π΄ΠΎΡΡΡΠΏΠ΅, Π·Π°ΠΏΡΠΎΡΡ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡΠ΅Π»ΡΠΌ, ΡΠ΅Ρ
Π½ΠΈΠΊΠΎ-ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅.
Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π²ΡΠ³ΠΎΠ΄Π½ΡΠΉ Π²Π°ΡΠΈΠ°Π½Ρ.
ΠΠ±Π»Π°ΡΡΡ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ: ΡΠ½Π΅ΡΠ³ΠΎΠ΄Π΅ΡΠΈΡΠΈΡΠ½ΡΠ΅ ΠΎΡΠ΄Π°Π»Π΅Π½Π½ΡΠ΅ ΡΠ°ΠΉΠΎΠ½Ρ, Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΡΠ΅ Ρ ΡΠΎΡΠΊΠΈ Π·ΡΠ΅Π½ΠΈΡ ΠΌΠ°Π»ΠΎΠΉ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΠΊΠΈ ΠΈ ΠΎΠ±Π»Π°Π΄Π°ΡΡΠΈΠ΅ ΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΠΎΠΌ ΠΠΠ, Π² ΡΠ°ΡΡΠ½ΠΎΡΡΠΈ Π²Π΅ΡΡΠΎΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»ΠΎΠΌ.
ΠΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠ°Ρ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΏΡΠΎΠ΅ΠΊΡΠ° Π·Π°ΠΊΠ»ΡΡΠ°Π΅ΡΡΡ Π² ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠΈ ΡΡΠΎΠΈΠΌΠΎΡΡΠΈ ΡΠ»Π΅ΠΊΡΡΠΎΡΠ½Π΅ΡΠ³ΠΈΠΈ Π² ΡΠ΅ΡΡΡ ΡΠ°Π·.Die Arbeit zielt auf die Losung der Energieversorgung von entlegenen Gebieten.
Gegenstand der Studie ist ein Hybrid wind-Diesel-System der Elektrizitatsversorgung, das sich im Suden vom Gebiet Kemerowo auf einer Hohe von 1260 Meter. In der Studie wurden fur die Analyse von Materialien in der offentlichkeit, Anfragen von Herstellern, die technisch-wirtschaftlichen Vergleich.
Die Studie ermittelt die Gunstigste Variante.
Einsatzbereich: energiedefizite Randgebiete, die vielversprechendsten in Bezug auf niedrige Energie und mit dem Potential der erneuerbaren Energien, insbesondere Energiepotenzial.
Die Wirtschaftseffektivitat des Projektes besteht in der Reduzierung der Kosten der Stromerzeugung in sechs mal
DNA hybridisation sensors for product authentication and tracing : state of the art and challenges
Abstract: The wide use of biotechnology applications in bioprocesses such as the food and beverages industry, pharmaceuticals, and medical diagnostics has led to not only the invention of innovative products but also resulted in consumer and environmental concerns over the safety of biotechnology-derived products. Controlling and monitoring the quality and reliability of biotechnology-derived products is a challenge. Current tracking and tracing systems such as barcode labels and radio frequency identification systems track the location of products from primary manufactures and/or producers throughout globalised distribution channels. However, when it comes to product authentication and tracing, simply knowing the location of the product in the supply chain is not sufficient. DNA hybridisation sensors allows for a holistic approach into product authentication and tracing in that they enable the attribution of active ingredients in biotechnology-derived products to their source. In this article, the state-of-the-art of DNA hybridisation sensors, with a focus on the application of graphene as the backbone, for product authentication and tracing is reviewed. Candidate DNA biocompatible materials, properties and transduction schemes that enable detection of DNA are covered in the discussion. Limitations and challenges of the use of DNA biosensing technologies in real-life environmental, biomedical and industrial fields as opposed to clean-cut laboratory conditions are also enumerated. By considering experimental research versus reality, this article outlines and highlights research needed to overcome commercialisation barriers faced by DNA biosensing technologies. In addition, the content is thought-provoking to facilitate development of cutting edge research activities in the field
ΠΠ½ΡΠ΅Π»Π»Π΅ΠΊΡΡΠ°Π»ΡΠ½Π°Ρ ΡΠΈΡΡΠ΅ΠΌΠ° ΠΏΠΎΠ΄Π΄Π΅ΡΠΆΠΊΠΈ ΠΏΡΠΈΠ½ΡΡΠΈΡ ΡΠΊΡΠΏΠ΅ΡΡΠ½ΡΡ ΡΠ΅ΡΠ΅Π½ΠΈΠΉ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Π°Π½Π°Π»ΠΈΠ·Π° ΠΎΡΠΊΡΡΡΡΡ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠΎΠ²
Electrophysiological methods to assess psycho-emotional state of a person based on medical nanosensors
Improved efficiency of organic solar cells using Au NPs incorporated into PEDOT:PSS buffer layer
Au based plasmonic phenomenon inside the hole transport layer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) of an organic solar cell based on blend of poly(3-hexylthiophene) (P3HT) and [6:6]-phenyl-C61-butyric acid (PCBM) is investigated. The concentration of the Au nanoparticles synthesized by wet chemical reduction is one of the key factors to strong light trapping when the spherical gold nanoparticles are blended into the PEDOT:PSS solution. Studies of the influence of the concentration of nanoparticles distribution in the PEDOT:PSS were carried out using UVβVis spectroscopy and atomic force microscopy. Electrical characteristics of the pristine device and of device with metallic nanostructures were analyzed from J βV characteristics to observe the plasmonic effects on the performance in the P3HT:PCBM organic solar cells. The origin of the photocurrent enhancements with varying Au nanoparticles concentrations on PEDOT:PSS are discussed.The University of theWitwatersrand, Material
Physics Research Institute, School of Physics & Chemistry; and MMU facilities at Wits, NRF and
Material Energy Research Group (MERG).http://scitation.aip.orgcontent/aip/journal/advaam2017Physic
Application of p electron theory to predict new materials for rewritable optical recording
Phase change recording is based upon the reversible phase transformation of a chalcogenide Te alloy between the crystalline and amorphous states using a focused laser. The formation of the micron-sized bit of information is distinguished from the difference in the optical properties of the two states. Until now most alloys utilised in optical data storage are based on ternary GeSbTe and the quartenary AgIn-Sb2Te alloys. To ensure that optical data storage remains competitive, new alloys with superior performance should be designed. However the design of new phase change alloys is hampered by the lack of a detailed theory for material selection. In the past the search for new alloys for optical data storage applications has been based on trial and error strategies. These approaches were expensive and time consuming especially when the exploration of the vast composition phase space is to be done. Therefore this work proposes some guidelines based on a newly developed theory to select and design new phase change materials with superior performance. These guidelines are based on the critical material requirements such as fast erasure, sufficient optical contrast and single isotropic structure specified for any suitable phase change media. To this end Au19In26Te55, Au18Sn23Te59, Au18Sb23Te59, In52Sb19Te29, and Ag18Sn26Te56 alloys have been prepared by combinatorial material synthesis approach to establish guidelines for selecting new phase change alloys. In optical data storage, recrystallization stands out as the technologically important process since it is the time limiting step. Suitable phase change media therefore require short recrystallization times in the order of nanoseconds. Therefore recrystallization has been performed on these alloys to determine their suitability as phase change media. Investigations on Au18Sb23Te59, and In52Sb19Te29 have shown recrystallization times of 110 and 76 ns, respectively thus making these alloys suitable for optical recording. While on one hand, long crystallization times in the order of 1 microsecond have been observed for the Au18Sn23Te59 no recrystallization was evident for the Au19In26Te55 alloy. This as will be mentioned later is attributed to the low optical contrast of this alloy. Even though the recrystallization time is significant for any suitable phase change media, not much information about the data transfer rate as well as the storage density can obtained from this parameter alone. Such information is obtained from the mechanisms of recrystallization since these mechanisms are crucial to improve the data transfer rates and storage densities. The classification of phase change alloys on the basis of nucleation and growth dominated alloys is technologically essential especially for alloys whose recrystallization times are dependent on the size of the bit. However the classification is hampered by the lack of a theory that separates these mechanisms for various alloy compositions. As a step towards establishing a criterion to distinguish these mechanisms, far field setup experiments on Au18Sb23Te59 and In52Sb19Te29 alloys have been performed to establish their mechanisms of recrystallization. The static tester results have shown that these alloys are growth-dominated. Using arguments based on previous experiments which have demonstrated that alloys with Tg/Tm 4. It therefore follows that the average electron number provides an easy and fast criterion for predicting suitable phase change alloys. The speed with which new alloys can be designed is determined to a great extent by the successful predictions by theoretical calculations of their crystal structures. Towards this end DFT calculations have been applied to determine the ground state structure of these alloys. The results have correctly predicted the thermodynamic structures of these alloys with the exception of Ag18Sn26Te56 alloy. Now that the area to look for suitable materials is identified as that of cubic structures, it is predicted that the scope of the search can be reduced further by DFT calculations to predict the most stable of the six possible candidates identified as constituents of the cubic structure
Application of p electron theory to predict new materials for rewritable optical recording
Phase change recording is based upon the reversible phase transformation of a chalcogenide Te alloy between the crystalline and amorphous states using a focused laser. The formation of the micron-sized bit of information is distinguished from the difference in the optical properties of the two states. Until now most alloys utilised in optical data storage are based on ternary GeSbTe and the quartenary AgIn-Sb2Te alloys. To ensure that optical data storage remains competitive, new alloys with superior performance should be designed. However the design of new phase change alloys is hampered by the lack of a detailed theory for material selection. In the past the search for new alloys for optical data storage applications has been based on trial and error strategies. These approaches were expensive and time consuming especially when the exploration of the vast composition phase space is to be done. Therefore this work proposes some guidelines based on a newly developed theory to select and design new phase change materials with superior performance. These guidelines are based on the critical material requirements such as fast erasure, sufficient optical contrast and single isotropic structure specified for any suitable phase change media. To this end Au19In26Te55, Au18Sn23Te59, Au18Sb23Te59, In52Sb19Te29, and Ag18Sn26Te56 alloys have been prepared by combinatorial material synthesis approach to establish guidelines for selecting new phase change alloys. In optical data storage, recrystallization stands out as the technologically important process since it is the time limiting step. Suitable phase change media therefore require short recrystallization times in the order of nanoseconds. Therefore recrystallization has been performed on these alloys to determine their suitability as phase change media. Investigations on Au18Sb23Te59, and In52Sb19Te29 have shown recrystallization times of 110 and 76 ns, respectively thus making these alloys suitable for optical recording. While on one hand, long crystallization times in the order of 1 microsecond have been observed for the Au18Sn23Te59 no recrystallization was evident for the Au19In26Te55 alloy. This as will be mentioned later is attributed to the low optical contrast of this alloy. Even though the recrystallization time is significant for any suitable phase change media, not much information about the data transfer rate as well as the storage density can obtained from this parameter alone. Such information is obtained from the mechanisms of recrystallization since these mechanisms are crucial to improve the data transfer rates and storage densities. The classification of phase change alloys on the basis of nucleation and growth dominated alloys is technologically essential especially for alloys whose recrystallization times are dependent on the size of the bit. However the classification is hampered by the lack of a theory that separates these mechanisms for various alloy compositions. As a step towards establishing a criterion to distinguish these mechanisms, far field setup experiments on Au18Sb23Te59 and In52Sb19Te29 alloys have been performed to establish their mechanisms of recrystallization. The static tester results have shown that these alloys are growth-dominated. Using arguments based on previous experiments which have demonstrated that alloys with Tg/Tm 4. It therefore follows that the average electron number provides an easy and fast criterion for predicting suitable phase change alloys. The speed with which new alloys can be designed is determined to a great extent by the successful predictions by theoretical calculations of their crystal structures. Towards this end DFT calculations have been applied to determine the ground state structure of these alloys. The results have correctly predicted the thermodynamic structures of these alloys with the exception of Ag18Sn26Te56 alloy. Now that the area to look for suitable materials is identified as that of cubic structures, it is predicted that the scope of the search can be reduced further by DFT calculations to predict the most stable of the six possible candidates identified as constituents of the cubic structure