scholarly journals Gallium oxide nanowires for UV detection with enhanced growth and material properties

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Badriyah Alhalaili ◽  
Ryan James Bunk ◽  
Howard Mao ◽  
Hilal Cansizoglu ◽  
Ruxandra Vidu ◽  
...  

AbstractIn the last decade, interest in the use of beta gallium oxide (β-Ga2O3) as a semiconductor for high power/high temperature devices and deep-UV sensors has grown. Ga2O3 has an enormous band gap of 4.8 eV, which makes it well suited for these applications. Compared to thin films, nanowires exhibit a higher surface-to-volume ratio, increasing their sensitivity for detection of chemical substances and light. In this work, we explore a simple and inexpensive method of growing high-density gallium oxide nanowires at high temperatures. Gallium oxide nanowire growth can be achieved by heating and oxidizing pure gallium at high temperatures (~ 1000 °C) in the presence of trace amounts of oxygen. This process can be optimized to large-scale production to grow high-quality, dense and long Ga2O3 nanowires. We show the results of morphological, structural, electrical and optical characterization of the β-Ga2O3 nanowires including the optical bandgap and photoconductance. The influence of density on these Ga2O3 nanowires and their properties will be examined in order to determine the optimum configuration for the detection of UV light.

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 601 ◽  
Author(s):  
Joana Figueira ◽  
Cristina Gaspar ◽  
José Tiago Carvalho ◽  
Joana Loureiro ◽  
Elvira Fortunato ◽  
...  

Low-cost and large-scale production techniques for flexible electronics have evolved greatly in recent years, having great impact in applications such as wearable technology and the internet of things. In this work, we demonstrate fully screen-printed UV photodetectors, successfully fabricated at a low temperature on a cork substrate, using as the active layer a mixture of zinc oxide nanoparticles and ethylcellulose. The photoresponse under irradiation with a UV lamp with peak emission at 302 nm exhibited a quasi-quadratic behavior directly proportional to the applied voltage, with a photocurrent of about 5.5 and 20 μA when applying 1.5 V and 5 V, respectively. The dark current stayed below 150 nA, while the rise and falling times were, respectively, below 5 and 2 s for both applied voltages. The performance was stable over continuous operation and showed a degradation of only 9% after 100 bending cycles in a 45 mm radius test cylinder. These are promising results regarding the use of this type of sensor in wearable applications such as cork hats, bracelets, or bags.


2014 ◽  
Vol 687-691 ◽  
pp. 2656-2659 ◽  
Author(s):  
Chang Li Sun ◽  
Dan Shi ◽  
Dong Mei Guo

With the application of the Internet of things and cloud computing technology, a large-scale production, sharing and application data age is gradually open, it will give the technical and commercial to be changed, also will change our way of the life. If the data is stored, it is always a pile of meaningless numbers, but if using the technology to realize data value, analyzes the data from the produce to the mining, finally consumed the entire process, only by making data, to make data services to the public. This paper will use the big data technology to mine, identify, organize and analyze the implied reader behavior in the structured and semi-structured data information, to search for readers of the implicit demand to improve the library service, resources, services, and reader demand and achieve the optimum configuration.


1992 ◽  
Vol 287 ◽  
Author(s):  
Thommy EkstrÖm

ABSTRACTDense single-phase α-, β- and O′-sialon cermics or mixed sialon ceramics without a glassy grain-boundary phase can be prepared at high temperatures and pressures, and these materials are well suited for high-temperature use, but they are usually brittle. Additional quantities of oxides of group IIIB metals in the periodic table are often added as sintering aids to achieve pressureless sintering and thereby to allow more complicated shapes to be manufactured directly and at lower costs. The most common additive is yttria, but the rare earth oxides are also of interest. All these oxides will promote the growth of elongated β crystals in the microstructure, and the fracture toughness will be improved considerably. Low-cost oxides like Nd2O3, La2O3 or CeO2 may replace Y2O3 without significantly impairing the mechanical properties at room temperature. The expensive rare-earth oxides like Sm2O3, Dy2O3 or Yb2O3 have been found to be as good additives as yttria, or even better, but improvements in mechanical properties are generally small and do not justify the use of these additives in large-scale production. The residual intergranular glassy phase usually found in the microstructure of metal-oxide-doped sialons will deteriorate the properties at very high temperatures, and this type of material is best suited for use at operation temperatures below 900-1000°C.


1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.


2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.


Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.


Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rozina Rashid ◽  
Muhammad Sohail

AbstractThe capacity of different Bacillus species to produce large amounts of extracellular enzymes and ability to ferment various substrates at a wide range of pH and temperature has placed them among the most promising hosts for the industrial production of many improved and novel products. The global interest in prebiotics, for example, xylooligosaccharides (XOs) is ever increasing, rousing the quest for various forms with expanded productivity. This article provides an overview of xylanase producing bacilli, with more emphasis on their capacity to be used in the production of the XOs, followed by the purification strategies, characteristics and application of XOs from bacilli. The large-scale production of XOs is carried out from a number of xylan-rich lignocellulosic materials by chemical or enzymatic hydrolysis followed by purification through chromatography, vacuum evaporation, solvent extraction or membrane separation methods. Utilization of XOs in the production of functional products as food ingredients brings well-being to individuals by improving defense system and eliminating pathogens. In addition to the effects related to health, a variety of other biological impacts have also been discussed.


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