Gas sensors are essential for detecting noxious gases that have a detrimental effect on people's health and welfare. Carbon quantum dots (CQDs) are the fundamental component of gas detectors. CQDs and graphene (Gr) were prepared using the electrochemical method. The gas sensitivity of these materials was evaluated at different temperatures (150, 200, 250 °C) to assess their effectiveness. Subsequently, experiments were conducted at different temperatures to ascertain that the combination of CQDs and Gr, with various percentages of Gr and CQDs, exhibited superior gas sensitization properties compared to CQDs alone. This was evaluated based on criteria such as sensitivity, recovery time, and reaction time. Interestingly, the combination was highly responsive. The quantum dots on glass substrates could detect NO2 gas at the abovementioned temperatures. Experimental evidence showed that the gas sensor can only detect graphene at low temperatures.
Abstract
financial market occupy very important place in the economic activity all over the world countris, and its importance increased with considerable technological progress in the world of transportation ,communications and information where its impact have spread over the whole world, which led to link the international economy in a kind of international relations so that the open policy became the prevailing trend in national and regional economies within the framework of the new world order.
the international economy has faced the financial crisis, global, that hit all world economies although the United States is the center of the crisis and the starting spark for it w
... Show MoreThis research set to indicate the role of the opportunity cost in the overall economic development (human and social development) by selecting the most appropriate alternative for the growth of the country in exchange for sacrificing profit limits to achieve this growth and development of the country, especially in the present circumstances of the country and after studying the reality of the economic case for him, as the problem lies with don't selecting the best alternative that enhances the gross domestic product, which extends to promote overall economic development and revive the industrial and agricultural sectors, productivity is more like Impotent, versus sacrifice alternative consumption may bring more financially lucrative than
... Show MoreBackground: White spot lesions are esthetic problems caused by subsurface enamel demineralization that seen as white opacity. Aim of the study: This study aimed to evaluate and to compare the color change after the treatment of the white spot lesions with resin nϔtrton and micro abrasion. Materials and Methods: rtϔ white spot lesions were generated on 48 premolar teeth by the use of a demineralization solution. The teeth were randomly divided using the Diagnodent into three study groups (16 teeth for each group) depending on the depth of the induced lesions: outer enamel, inner enamel and outer dentine. Then each group was fatherly subdivided into two groups (8 teeth for each group) the ϔrst group was treated wit
... Show MoreThe current study was conducted in Baghdad governorate (Karkh and Al-Rasafa regions) which included collecting 50 samples of freshly slaughtered sheep meat randomly collected from local slaughter areas and approved governmental slaughterhouses (25 liver and 25 ulna muscles). The results of the aflatoxin B1 detection showed that all samples were contaminated with this toxin at different concentrations ranging from 25–422 ppb and 65–492 ppb for each ulna muscles and liver, respectively. The histopathological and immunological study was conducted in meat samples containing higher and lower concentrations of the toxin. The results of the pathological study in the liver revealed that the concentration (492 ppb) caused thickening of t
... Show MoreThe concept of forming the living space in the American strategic thought has an
important position it is regarded as an strategic movement that it supports the American
United States with the huge capabilities in its own concern that enables it to approach of
American administration , we find that of different historical periods it works to establish that
the geopolitical dimension which is accompanied with the ability of American response for
the evens that in its own turn enables the American united states to seize the growing chances
in the global strategic environment This study includes five chapters :
- Chapter one: The idea of living space.
- Chapter two: Geopolitical dimension of living space theory.
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Live the present companies in a competitive business environment going on and try to achieve excellence in their industry through the marketing of their products and achieve greater market share as possible to ensure its continued existence, and perhaps the concept of time production, which confirms, in essence, on the need to reduce inventory to a minimum in the production process as well as the concept of the marketing information system which asserts, in essence, to document all the events that are related to the marketing of the product provided by the production process, together constitute the subject deserves research and investigation as they have raised well-known in the fields of production management and marketing management.
... Show MoreThe present study was conducted on the Iraqi Pin-tailed Sandgrouse (Pterocles alchata) to study the lung's morphological description and histological structure. This study was used 5 samples of adult male sandgrouse bird. The birds were dissected. The lungs were removed from the coelomic cavity, cleaned to remove impurities, and photographed to describe their morphological features. The samples were fixed using formalin (10%) solution for 36-48 hours and then preserved in alcohol (70%) to prepare the microscopic slides. The results showed that the lung of the Iraqi sandgrouse bird is red in color, has a trapezoidal shape and has three surfaces (costal, visceral, and vertebral). The costal surface shows ribs impressions that extend f
... Show MoreAn innovative greenhouse which integrates a conventional greenhouse with roof mounted solar air heaters is used in this investigation. This design reduces the solar radiation incoming to the greenhouse in summer which reduced the load and cost of greenhouse cooling and provides a means of solar heating. Experimental measurements of the internal air and internal soil sub-layer temperatures in the greenhouse, without crops, were performed in Baghdad University, Baghdad, Iraq (33.3 °N, 44.4 °E). Measurements were recorded for clear and partly cloudy winter days. A dynamic model was developed to predict the all internal temperatures of the greenhouse. This model includes soil surface heat exchange with the greenhouse air which was found to gi
... Show MoreNanostructured Al2O3has been applied as a protective coating against corrosion of the carbon steel (C.S) in seawater environment (3.5% NaCl) at temperatures range (298-328)K. Aluminananoparticles were deposited on carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(acrylic acid) (PAA) as polymeric charging agent. Meanwhile, thesurface morphology was examined using Atomic-force microscopy (AFM). The cross-section AFM showed that the particles sizes for the Al2O3 NPs is around 60-80 nm. The anticorrosion behaviour of coated C.S was investigated in 3.5% NaCl at temperature range 298-328 K by potentiodynamic polarization measurements. Results show that using PAA in suspension coat incr
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