Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after th...Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180℃ and cooking temperatures (160℃, 180℃, 200℃) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.展开更多
<strong>Context:</strong> Substandard and falsified medicines are circulating in low-income countries mostly without any control. We availed a simple and not expensive UV-Vis spectroscopic method to evalua...<strong>Context:</strong> Substandard and falsified medicines are circulating in low-income countries mostly without any control. We availed a simple and not expensive UV-Vis spectroscopic method to evaluate the quality of tramadol in Kisangani before and during the Covid-19 period. <strong>Methods:</strong> For the analytical quantitative method, an experimental design was applied to set up the optimal levels of the selected factors, namely, pH of dissolution medium, type of cuvette, and wavelength. Taking into account the capsule pharmaceutical formulation within 80 - 120 μg·mL<sup>-1</sup> concentration range, we analyzed 89 tramadol samples from pharmacies and hospitals of the six Kisangani municipalities. <strong>Results:</strong> pH showed a significant effect on absorbance, whereas quartz cuvette and wavelength did not. A typical 100 μg·mL<sup>-1</sup> tramadol solution gave an absorbance of 0.64 at 272 nm. Validation highlighted a matrix effect observed with a 6% bias. A correction factor of 0.9372 allowed to improve the accuracy profile, which were then totally included within the 10% acceptance limits. Quality control revealed that 25 samples out of 89 were not compliant in terms of manufacturing license, registration status in DRC and content as well. <strong>Conclusion:</strong> This study showed that the strengthening of analytical strategy in Kisangani is a need.展开更多
The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and...The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and sodium cellulose glycolate as dispersing agent.The results showed that palladiumd thioglucoside method could be taken as a quick,easy and precise quantitative analysis method to determine thioglucoside in cabbage.展开更多
Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various...Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various techniques, including optical analysis, structural analysis, transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). This thorough process instills confidence in the accuracy of our findings. The results unveiled that the silver nanoparticles had a diameter of less than 20 nm, a finding of great importance. The absorption spectrum decreased in the peak wavelength range (405 - 394 mm) with increasing concentrations of Ag nanoparticles in the range (1 - 5%). The XRD results indicated a cubic crystal structure for silver nanoparticles with the lattice constant (a = 4.0855 Å), and Miller indices were (111), (002), (002), and (113). The simulation on the XRD pattern showed a face center cubic phase with space group Fm-3m, providing valuable insights into the structure of the nanoparticles.展开更多
Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five diff...Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five different drying methods, steam treated and exposed to weathering. Their colors were measured using a spectrophotometer and comparisons made both among species and drying methods. For Japanese and Korean pines, high temperature dried and steam-dried specimens showed distinct color differences compared with the controls. Steam treatment discolored the dried specimens of Japanese and Korean pines but did not discolor those of larch. After weathering for 144 days the specimens of Japanese pine showed slight color differences among drying methods.展开更多
Photocatalytic degradations of p-nitrochlorbenzene (p-NCB) with distilled water wereinvestigated with ZnO crystals (catalyst) of 70nm in diameter under UV irradiation.The suitable experimental conditions are determine...Photocatalytic degradations of p-nitrochlorbenzene (p-NCB) with distilled water wereinvestigated with ZnO crystals (catalyst) of 70nm in diameter under UV irradiation.The suitable experimental conditions are determined as: ZnO 0.25g, pH 7, p-NCBconcentration 30mg/L. These variables in terms of the degradation rate have beendiscussed, which was defined as the rate of the initial degradation to the final degrada-tion of p-NCB. When all of the experimental degradation rate values are plotted as afunction of irradiation time, all of the points appeared on a single line for wide range ofp-NCB degradations. On the basis of these results, it has been concluded that at lowerZnO catalyst amount, much of the light is transmitted through the slurry in the con-tainer beaker, while at higher catalyst amount, all the incident photons are observedby the slurry. Degradation rates of p-NCB were found to decrease with increasingsolution pH. It has been concluded that the maximum degradation rate values of p-NCB under principally the same experimental conditions mentioned above are 97.4%,98.8% and 95.5% at 100min respectively. The results suggest that the photocatalyticdegradation is initiated by an oxidation of the p-NCB through ZnO surface-adsorbedhydroxyl radicals. Absorption spectra are recorded using spectrophotometer before andafter UV-irradiation in the wavelength range 200-400nm at room temperature. Itis found that the variation of irradiation time over the range 20-100min resulted inchange in the form of the spectrum linear absorption and a higher maximum valuewill be obtained at longer irradiation time.展开更多
A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural like the ...A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural like the UV-Vis absorption spectrometer, Ttransmission Electron Microscopy (TEM), Field-Emission Scanning Electron microscope (FESEM), and X-ray diffraction (XRD). The practical results exhibited the absorption spectrum of the prepared nanoparticles at (357 nm), it was found that there is a relationship between the positions of the optical absorption peak and the size of the silver nanoparticles. The analysis of TEM results showed the presence of nanoparticles in the range (20 nm). The analyzing of XRD results explained the crystal structure for silver nanoparticles. It is found a cubic unit cell have a lattice constants (a = 4.0855 <span style="white-space:nowrap;">Å</span>), with the Miller indices were (111), (002), (002), and (113).展开更多
文摘Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180℃ and cooking temperatures (160℃, 180℃, 200℃) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.
文摘<strong>Context:</strong> Substandard and falsified medicines are circulating in low-income countries mostly without any control. We availed a simple and not expensive UV-Vis spectroscopic method to evaluate the quality of tramadol in Kisangani before and during the Covid-19 period. <strong>Methods:</strong> For the analytical quantitative method, an experimental design was applied to set up the optimal levels of the selected factors, namely, pH of dissolution medium, type of cuvette, and wavelength. Taking into account the capsule pharmaceutical formulation within 80 - 120 μg·mL<sup>-1</sup> concentration range, we analyzed 89 tramadol samples from pharmacies and hospitals of the six Kisangani municipalities. <strong>Results:</strong> pH showed a significant effect on absorbance, whereas quartz cuvette and wavelength did not. A typical 100 μg·mL<sup>-1</sup> tramadol solution gave an absorbance of 0.64 at 272 nm. Validation highlighted a matrix effect observed with a 6% bias. A correction factor of 0.9372 allowed to improve the accuracy profile, which were then totally included within the 10% acceptance limits. Quality control revealed that 25 samples out of 89 were not compliant in terms of manufacturing license, registration status in DRC and content as well. <strong>Conclusion:</strong> This study showed that the strengthening of analytical strategy in Kisangani is a need.
文摘The ultraviolet-visible light spectrophotometer method was adopted to determine thioglucoside in cabbage with the seeds.Individual plant of cabbage was used as test materials,palladium chloride as complexing agent and sodium cellulose glycolate as dispersing agent.The results showed that palladiumd thioglucoside method could be taken as a quick,easy and precise quantitative analysis method to determine thioglucoside in cabbage.
文摘Our research introduces a groundbreaking chemical reduction method for synthesizing silver nanoparticles, marking a significant advancement in the field. The nanoparticles were meticulously characterized using various techniques, including optical analysis, structural analysis, transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). This thorough process instills confidence in the accuracy of our findings. The results unveiled that the silver nanoparticles had a diameter of less than 20 nm, a finding of great importance. The absorption spectrum decreased in the peak wavelength range (405 - 394 mm) with increasing concentrations of Ag nanoparticles in the range (1 - 5%). The XRD results indicated a cubic crystal structure for silver nanoparticles with the lattice constant (a = 4.0855 Å), and Miller indices were (111), (002), (002), and (113). The simulation on the XRD pattern showed a face center cubic phase with space group Fm-3m, providing valuable insights into the structure of the nanoparticles.
文摘Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five different drying methods, steam treated and exposed to weathering. Their colors were measured using a spectrophotometer and comparisons made both among species and drying methods. For Japanese and Korean pines, high temperature dried and steam-dried specimens showed distinct color differences compared with the controls. Steam treatment discolored the dried specimens of Japanese and Korean pines but did not discolor those of larch. After weathering for 144 days the specimens of Japanese pine showed slight color differences among drying methods.
文摘Photocatalytic degradations of p-nitrochlorbenzene (p-NCB) with distilled water wereinvestigated with ZnO crystals (catalyst) of 70nm in diameter under UV irradiation.The suitable experimental conditions are determined as: ZnO 0.25g, pH 7, p-NCBconcentration 30mg/L. These variables in terms of the degradation rate have beendiscussed, which was defined as the rate of the initial degradation to the final degrada-tion of p-NCB. When all of the experimental degradation rate values are plotted as afunction of irradiation time, all of the points appeared on a single line for wide range ofp-NCB degradations. On the basis of these results, it has been concluded that at lowerZnO catalyst amount, much of the light is transmitted through the slurry in the con-tainer beaker, while at higher catalyst amount, all the incident photons are observedby the slurry. Degradation rates of p-NCB were found to decrease with increasingsolution pH. It has been concluded that the maximum degradation rate values of p-NCB under principally the same experimental conditions mentioned above are 97.4%,98.8% and 95.5% at 100min respectively. The results suggest that the photocatalyticdegradation is initiated by an oxidation of the p-NCB through ZnO surface-adsorbedhydroxyl radicals. Absorption spectra are recorded using spectrophotometer before andafter UV-irradiation in the wavelength range 200-400nm at room temperature. Itis found that the variation of irradiation time over the range 20-100min resulted inchange in the form of the spectrum linear absorption and a higher maximum valuewill be obtained at longer irradiation time.
文摘A silver nanostructures prepared by using chemical reduction method. The silver nanoparticles were prepared with diameters of about (20 nm). Numerous techniques had been used to study the optical, structural like the UV-Vis absorption spectrometer, Ttransmission Electron Microscopy (TEM), Field-Emission Scanning Electron microscope (FESEM), and X-ray diffraction (XRD). The practical results exhibited the absorption spectrum of the prepared nanoparticles at (357 nm), it was found that there is a relationship between the positions of the optical absorption peak and the size of the silver nanoparticles. The analysis of TEM results showed the presence of nanoparticles in the range (20 nm). The analyzing of XRD results explained the crystal structure for silver nanoparticles. It is found a cubic unit cell have a lattice constants (a = 4.0855 <span style="white-space:nowrap;">Å</span>), with the Miller indices were (111), (002), (002), and (113).
