scholarly journals Sensing Properties of Oxidized Nanostructured Silicon Surface on Vaporized Molecules

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 119 ◽  
Author(s):  
Nikola Baran ◽  
Hrvoje Gebavi ◽  
Lara Mikac ◽  
Davor Ristić ◽  
Marijan Gotić ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Ammonia Gas ◽  
Sensing Properties ◽  
Long Term Stability ◽  
The Past ◽  
Oxygen Treatment ◽  
Ambient Concentration ◽  
Potential Use

Porous silicon has been intensely studied for the past several decades and its applications were found in photovoltaics, biomedicine, and sensors. An important aspect for sensing devices is their long–term stability. One of the more prominent changes that occur with porous silicon as it is exposed to atmosphere is oxidation. In this work we study the influence of oxidation on the sensing properties of porous silicon. Porous silicon layers were prepared by electrochemical etching and oxidized in a tube furnace. We observed that electrical resistance of oxidized samples rises in response to the increasing ambient concentration of organic vapours and ammonia gas. Furthermore, we note the sensitivity is dependent on the oxygen treatment of the porous layer. This indicates that porous silicon has a potential use in sensing of organic vapours and ammonia gas when covered with an oxide layer.

Risking Debt for Honor

2017 ◽  
Vol 43 (1) ◽  
pp. 51-71
Author(s):  
Jennifer R. Cash
Keyword(s):  
Social Relations ◽  
Social Life ◽  
Urban Migration ◽  
Long Term Stability ◽  
The Past ◽  
Political Upheaval ◽  
The Social ◽  
Rural Urban Migration ◽  
The Republic

Research on godparenthood has traditionally emphasized its stabilizing effect on social structure. This article, however, focuses attention on how the practices and discourses associated with marital sponsorship in the Republic of Moldova ascribe value to the risks and uncertainties of social life. Moldova has experienced substantial economic, social, and political upheaval during the past two decades of postsocialism, following a longer period of Soviet-era modernization, secularization, and rural–urban migration. In this context, godparenthood has not contributed to the long-term stability of class structure or social relations, but people continue to seek honor and social respect by taking the social and economic risks involved in sponsoring new marriages.

scholarly journals Enhanced Methane Sensing Properties of WO3 Nanosheets with Dominant Exposed (200) Facet via Loading of SnO2 Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 351 ◽  
Author(s):  
Dongping Xue ◽  
Junjun Wang ◽  
Yan Wang ◽  
Guang Sun ◽  
Jianliang Cao ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Defect Density ◽  
Sno2 Nanoparticles ◽  
High Reactivity ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Subsequent Calcination

Methane detection is extremely difficult, especially at low temperatures, due to its high chemical stability. Here, WO3 nanosheets loaded with SnO2 nanoparticles with a particle size of about 2 nm were prepared by simple impregnation and subsequent calcination using SnO2 and WO3·H2O as precursors. The response of SnO2-loaded WO3 nanosheet composites to methane is about 1.4 times higher than that of pure WO3 at the low optimum operating temperature (90 °C). Satisfying repeatability and long-term stability are ensured. The dominant exposed (200) crystal plane of WO3 nanosheets has a good balance between easy oxygen chemisorption and high reactivity at the dangling bonds of W atoms, beneficial for gas-sensing properties. Moreover, the formation of a n–n type heterojunction at the SnO2-WO3 interface and additionally the increase of specific surface area and defect density via SnO2 loading enhance the response further. Therefore, the SnO2-WO3 composite is promising for the development of sensor devices to methane.

The End of Family Business? The Mittelstand and German Capitalism in Transition, 1949–2000

2006 ◽  
Vol 80 (2) ◽  
pp. 263-295 ◽  
Author(s):  
Hartmut Berghoff
Keyword(s):  
Family Business ◽  
Family Firms ◽  
German Economy ◽  
Term Stability ◽  
Long Term Stability ◽  
Sociocultural Environment ◽  
The Past ◽  
The 1960S ◽  
Modern Form

TheMittelstandsector of the German economy, which is made up of small and medium-sized family firms, is generally not mentioned in debates about German capitalism. This article makes the case that the focus of research on the German economy should shift from large corporate structures to these smaller firms. The classic Mittelstand model, which dominated the economy until about 1970, was characterized by identity of ownership and management, strong emotional investment by owners and staff, and an emphasis on continuity, paternalism, and independence. Beginning in the 1960s, this model was undermined by fundamental changes in the country's economic and sociocultural environment. In response, the firms abandoned a number of their traditional attributes, a process that led to the demise of some businesses and the regeneration of others. Although the modern form adopted by the surviving Mittelstand firms allows them to be less dependent on individual families, to enjoy more access to external capital, and to display more openness and international orientation, they can no longer rely on the prospect of long-term stability, as they did in the past.

The End of Family Business? The Mittelstand and German Capitalism in Transition, 1949–2000

2006 ◽  
Vol 80 (2) ◽  
pp. 263-295 ◽  
Author(s):  
Hartmut Berghoff
Keyword(s):  
Family Business ◽  
Family Firms ◽  
German Economy ◽  
Term Stability ◽  
Long Term Stability ◽  
Sociocultural Environment ◽  
The Past ◽  
The 1960S ◽  
Modern Form

TheMittelstandsector of the German economy, which is made up of small and medium-sized family firms, is generally not mentioned in debates about German capitalism. This article makes the case that the focus of research on the German economy should shift from large corporate structures to these smaller firms. The classic Mittelstand model, which dominated the economy until about 1970, was characterized by identity of ownership and management, strong emotional investment by owners and staff, and an emphasis on continuity, paternalism, and independence. Beginning in the 1960s, this model was undermined by fundamental changes in the country's economic and sociocultural environment. In response, the firms abandoned a number of their traditional attributes, a process that led to the demise of some businesses and the regeneration of others. Although the modern form adopted by the surviving Mittelstand firms allows them to be less dependent on individual families, to enjoy more access to external capital, and to display more openness and international orientation, they can no longer rely on the prospect of long-term stability, as they did in the past.

scholarly journals Nanowire-Based Biosensors: From Growth to Applications

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 679 ◽  
Author(s):  
Pranav Ambhorkar ◽  
Zongjie Wang ◽  
Hyuongho Ko ◽  
Sangmin Lee ◽  
Kyo-in Koo ◽  
...  
Keyword(s):  
Volume Ratio ◽  
High Ionic Strength ◽  
Comprehensive Review ◽  
Biomedical Sensors ◽  
Long Term Stability ◽  
The Past ◽  
Nanowire Sensor ◽  
Working Principle ◽  
Near Future

Over the past decade, synthesized nanomaterials, such as carbon nanotube, nanoparticle, quantum dot, and nanowire, have already made breakthroughs in various fields, including biomedical sensors. Enormous surface area-to-volume ratio of the nanomaterials increases sensitivity dramatically compared with macro-sized material. Herein we present a comprehensive review about the working principle and fabrication process of nanowire sensor. Moreover, its applications for the detection of biomarker, virus, and DNA, as well as for drug discovery, are reviewed. Recent advances including self-powering, reusability, sensitivity in high ionic strength solvent, and long-term stability are surveyed and highlighted as well. Nanowire is expected to lead significant improvement of biomedical sensor in the near future.

scholarly journals Synthesis of a Flower-Like g-C3N4/ZnO Hierarchical Structure with Improved CH4 Sensing Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 724 ◽  
Author(s):  
Xiaojie Li ◽  
Yanwei Li ◽  
Guang Sun ◽  
Na Luo ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Carbon Nitride ◽  
Fast Response ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Response Recovery ◽  
Calcination Method

In this paper, a hierarchical structure of graphite carbon nitride (g-C3N4) modified ZnO (g-C3N4/ZnO) was synthesized using a simple precipitation-calcination method. Through this method, g-C3N4 nanosheets with a controlled content were successfully decorated on the petals of flower-like ZnO. Various techniques were used to confirm the successful formation of the g-C3N4/ZnO hierarchical structure. The methane (CH4) sensing properties of g-C3N4/ZnO sensor were investigated. The result exhibited that after decorating ZnO with g-C3N4, the CH4 sensing performances of the fabricated sensor were remarkably improved. At the optimum operating temperature of 320 °C, the response of the sensor fabricated with CNZ-3 (the sample with an optimum content of g-C3N4) towards 1000 ppm CH4 was as high as 11.9 (Ra/Rg), which was about 2.2 times higher than that of the pure ZnO sensor (5.3). In addition, the CNZ-3 sensor also exhibited a fast response/recovery speed (15/28 s) and outstanding long-term stability. The enhancing CH4 sensing mechanism may be contributed to enlarged surface area, pore structure, and g-C3N4-ZnO n-n junction.

scholarly journals Infrastructure autopoiesis: requisite variety to engage complexity

2022 ◽  
Author(s):  
Mikhail V Chester ◽  
Braden Allenby
Keyword(s):  
Infrastructure Systems ◽  
Long Term Stability ◽  
The Core ◽  
The Past ◽  
Knowledge Processes ◽  
Requisite Variety ◽  
Horizon Scanning ◽  
The Face ◽  
Conditions Of Stability

Abstract Infrastructure systems must change to match the growing complexity of the environments they operate in. Yet the models of governance and the core technologies they rely on are structured around models of relative long-term stability that appear increasingly insufficient and even problematic. As the environments in which infrastructure function become more complex, infrastructure systems must adapt to develop a repertoire of responses sufficient to respond to the increasing variety of conditions and challenges. Whereas in the past infrastructure leadership and system design has emphasized organization strategies that primarily focus on exploitation (e.g., efficiency and production, amenable to conditions of stability), in the future they must create space for exploration, the innovation of what the organization is and does. They will need to create the abilities to maintain themselves in the face of growing complexity by creating the knowledge, processes, and technologies necessary to engage environment complexity. We refer to this capacity as infrastructure autopoiesis. In doing so infrastructure organizations should focus on four key tenets. First, a shift to sustained adaptation – perpetual change in the face of destabilizing conditions often marked by uncertainty – and away from rigid processes and technologies is necessary. Second, infrastructure organizations should pursue restructuring their bureaucracies to distribute more resources and decisionmaking capacity horizontally, across the organization’s hierarchy. Third, they should build capacity for horizon scanning, the process of systematically searching the environment for opportunities and threats. Fourth, they should emphasize loose fit design, the flexibility of assets to pivot function as the environment changes. The inability to engage with complexity can be expected to result in a decoupling between what our infrastructure systems can do and what we need them to do, and autopoietic capabilities may help close this gap by creating the conditions for a sufficient repertoire to emerge.

Long-Term Stability of Thermally-Carbonized Porous Silicon Humidity Sensor

2005 ◽  
Vol 876 ◽  
Author(s):  
J. Tuura ◽  
M. Björkqvist ◽  
J. Salonen ◽  
V-P. Lehto
Keyword(s):  
Porous Silicon ◽  
Humidity Sensor ◽  
Electrical Characteristics ◽  
Term Stability ◽  
Long Term Stability ◽  
Other Hand ◽  
Detection Frequency

AbstractThermally-carbonized porous silicon humidity sensor showed ageing affecting electrical characteristics. During the first month the variations in electrical characteristics were very distinctive. The decline in the sensitivity of the sensor after three months storage was found to be 37%, however, the sensitivity was still over 200%. When aged, the sensor stabilized and only minor variations on capacitance were noticeable. Sensitivity, on other hand, remains nearly constant. The hysteresis of the sensor did not change remarkably during storage. The variations on capacitance values at different relative humidities during storage were measured as a function of detection frequency. This showed an interesting feature of the ageing of the sensor, which is also discussed.

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