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Heavy Metal and Air Quality Assessment around a Healthcare Waste Incinerator Facility in Nigeria
Useh Uwem Jonah,
Muhammed Mohammed Alhassan,
Useh Mercy Uwem
Issue:
Volume 2, Issue 6, November 2017
Pages:
65-70
Received:
8 September 2017
Accepted:
20 September 2017
Published:
5 November 2017
Abstract: Waste incineration represents a prominent waste treatment strategy applied towards the treatment of hospital waste in many developing countries. Adequate pollution control limits the exposure of waste workers and the community to toxic contaminants in air emissions and ash. This study examined the air quality emissions of acid gases (Nitric Oxide, Sulphur Oxides, Hydrogen Sulphides, Ammonia, Carbon Monoxide, Methane) using a portable Haz-Dust Particulate detection system. Determination of heavy metals (Cadmuim, Chromium, Cobalt, Copper, Nickel, Iron, Lead, Magnesium, Manganese and Zinc) released in the flu ash samples in the neighboring environments at the front and back of the incinerator, including the electrical station and school block around the Federal Government College, Keffi was measured using an Atomic Absorption Spectrophotometer (iCE 3000 series). The results showed that the particulate emissions were in the range of 0.10-0.26 (mg/m3). Carbon monoxide levels detected were in the range of 5-12 ppm. The distribution of acid gases ranged between 0.01-0.07 (ppm) for CO, SO2, NH3, H2S and NO2. No measureable concentrations of Chromium, Copper and Lead was detected. The concentrations of Iron (0.202 mg/l) and Magnesium (18.309 mg/l) were below the WHO acceptable limits while Cobalt (0.171 mg/l), Nickel (3.466 mg/l), Manganese (3.589 mg/l) and Zinc (10.61 mg/l) were higher than approved limits. Improvements are required for the medical waste incinerator in this study by integrating addition process treatment systems to reduce environmental pollutants being released.
Abstract: Waste incineration represents a prominent waste treatment strategy applied towards the treatment of hospital waste in many developing countries. Adequate pollution control limits the exposure of waste workers and the community to toxic contaminants in air emissions and ash. This study examined the air quality emissions of acid gases (Nitric Oxide, ...
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Recent Advances in the Flame Synthesis of Carbon Nanotubes
Issue:
Volume 2, Issue 6, November 2017
Pages:
71-89
Received:
15 September 2017
Accepted:
18 October 2017
Published:
15 November 2017
Abstract: Significant progress has been made not only in improving the yields of carbon nanotubes, but also in gaining a profound fundamental understanding of the growth processes. Flames are emerging as a powerful tool for the synthesis of carbon nanotubes and carbon nanofibers. The flame volume provides a carbon-rich chemically reactive environment capable of generating nanostructures during short residence times in a continuous single-step process. The present work provides a concise review of the advances made over the past two decades in the areas of flame synthesis of carbon nanotubes and carbon nanofibers. An overview of existing flame methods to synthesize carbon nanotubes is first provided. Various catalytic materials, fuel types, and flame configurations have been employed in an attempt to achieve controlled synthesis of carbon nanotubes and carbon nanofibers. Diffusion and premixed flames in counter-flow and co-flow geometries are also discussed. Various hydrocarbon fuels, oxygen enrichment, and dilution with inert gases are then examined in detail. The ability to synthesize and control carbon nanotubes and carbon nanofibers is essential for the fabrication of nanomechanical and electrical devices. A fundamental understanding of the growth mechanism and development of control methods is critically important to address these issues. The purpose of the present review is to clarify the growth mechanisms and achieve controlled flame synthesis of carbon nanotubes and carbon nanofibers.
Abstract: Significant progress has been made not only in improving the yields of carbon nanotubes, but also in gaining a profound fundamental understanding of the growth processes. Flames are emerging as a powerful tool for the synthesis of carbon nanotubes and carbon nanofibers. The flame volume provides a carbon-rich chemically reactive environment capable...
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Structural and Dielectric Properties of Lanthanum Doped CaCu3Ti4O12 for Capacitor Application
Anshuman Srivastava,
Om Parkash,
Devendra Kumar,
Pralay Maiti
Issue:
Volume 2, Issue 6, November 2017
Pages:
90-93
Received:
24 September 2017
Accepted:
26 October 2017
Published:
15 November 2017
Abstract: CaCu3Ti4O12 (CCTO) is a novel material with high relative dielectric constant and low loss tangent, CCTO belongs to a family of oxides of the type ACu3Ti4O12 (A=Ca, Cd, Sr, Na, Th). CaCu3Ti4O12 was first reported by Subramanian et al., to have an unusually high dielectric constant (~10,000) at 1 kHz. It is well known that dielectric properties of CCTO are strongly dependent upon the processing conditions as well as on doping. Semi-wet route was used to synthesise samples of CaCu3Ti4O12 and Ca(1-3x/2)LaxCu3Ti4O12 (x=0.01). Analytical grade chemicals, Ca(NO3)2.4H2O, La(NO3)3.6H2O, Cu(NO3)2.3H2O, titanium dioxide and citric acid having purity better than 99.95% were used as starting materials. The formation of single-phase solid solutions was confirmed by the absence characteristic lines of constituent’s oxides in the XRD patterns. Dielectric measurement of undoped and La doped CCTO has been performed using four probe novocontrol set up (ZG4) in a wide range of temperature starting from the room temperature. With La doping in CCTO there is an increase in the value of dielectric constant in comparison to undoped CCTO.
Abstract: CaCu3Ti4O12 (CCTO) is a novel material with high relative dielectric constant and low loss tangent, CCTO belongs to a family of oxides of the type ACu3Ti4O12 (A=Ca, Cd, Sr, Na, Th). CaCu3Ti4O12 was first reported by Subramanian et al., to have an unusually high dielectric constant (~10,000) at 1 kHz. It is well known that dielectric properties of C...
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A New Empirical Method for Estimating the Refractive Index of Oxide Glasses Using Internal Structure Information
Hossam Mohamed Gomaa,
Saeid Mohamed EL Katlawy
Issue:
Volume 2, Issue 6, November 2017
Pages:
94-96
Received:
15 September 2017
Accepted:
24 October 2017
Published:
3 December 2017
Abstract: This paper is a simple idea aims to how to get an imagination about the variation of glass refractive index with its internal structure. In the present work an empirical equation for the refractive index of a glass sample has been achieved as function of both the glass molar Volume and the glass electronegativity. Like this equation, may be used to determine and estimate the refractive index value of an inorganic oxide glass sample, if its density measured with high accuracy.
Abstract: This paper is a simple idea aims to how to get an imagination about the variation of glass refractive index with its internal structure. In the present work an empirical equation for the refractive index of a glass sample has been achieved as function of both the glass molar Volume and the glass electronegativity. Like this equation, may be used to...
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PEG-200 Assisted Sonochemical Synthesis of Cerium (Ce3+) Doped Copper Oxide (CuO) Nano-Composites and Their Photocatalytic Activities
Sonali P. Chaudhari,
Anjali B. Bodade,
Prashant D. Jolhe,
Satish P. Meshram,
Gajanan N. Chaudhari
Issue:
Volume 2, Issue 6, November 2017
Pages:
97-102
Received:
24 September 2017
Accepted:
18 October 2017
Published:
8 December 2017
Abstract: CuO nanocomposites with different Ce3+ doping concentrations (0, 0.5, 1.0, 1.5, 3.0 and 5.0 mol%) were synthesized by PEG-200 assisted facile sonochemical method. The as-synthesized composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible absorption spectroscopy. Further, these composites were evaluated for photodegradation activities towards MB dye under sunlight irradiation. The XRD results demonstrated that CuO nanocomposites exhibits monoclinic phase and the crystallinity decreases with increasing Ce3+ doping concentration. The as-synthesized nanocomposites exhibited vesicular morphology with diameters ranging from 50 to 100nm. UV-visible absorption spectra results demonstrated that these nanocomposites exhibit strong absorption in the visible region and the absorption intensity increases with increasing Ce3+ doping concentration. The photocatalytic experiments using as-synthesized nanocomposites for degradation of Methylene blue (MB) dye revealed that, compared to undoped CuO; Ce3+ doped CuO nanocomposites exhibited improved photodegradation ability. The photodegradation rate was maximum for 3.0 mol% Ce3+ doped CuO which showed 98% degradation within 180 mins under sunlight irradiation. Recycling experiments demonstrated good stability of as-synthesized nanocomposites even after threere cycles.
Abstract: CuO nanocomposites with different Ce3+ doping concentrations (0, 0.5, 1.0, 1.5, 3.0 and 5.0 mol%) were synthesized by PEG-200 assisted facile sonochemical method. The as-synthesized composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible absorption spectroscopy. Further, these com...
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