Calidad del color del pimentón: Efecto de tratamientos de secado al natural y al aire.

Color, browning compounds formation and total carotenoids as indicator of paprika quality were investigated under air and natural drying processes. The data resulted from air drying experiments showed an inversely relationship between the progress in temperature (40, 60 and 80° C) and the paprika quality. In natural dried samples, three different treatments were carried out (sun, dark drying and blanching + sun drying). The data revealed an irregular pattern characterized by two stages: 1 st one is biosynthetic and the second is degradative with more profound effect in light more than darkness. Multilinear regression data analysis was also employed to simulate the results especially the changes in total carotenoids as a function of time. Sensory evaluation for color of the samples indicated a large variation in responses of panelists. Low temperature treatment was recommended to favour the quality of paprika if the rate of forming browning compounds is reduced.Bajo procesos de secado al natural y al aire se han investigado el color, la formación de compuestos de pardeamiento y los carotenoides totales como indicadores de la calidad del pimentón. Los datos obtenidos a partir de experimentos de secado al aire mostraron una relación inversa entre el aumento de la temperatura (40, 60 y 80° C) y la calidad del pimentón. En muestras secadas al natural, se llevaron a cabo tres tratamientos diferentes (sol, secado en la oscuridad y decolorado + secado al sol). Los datos revelaron un comportamiento irregular caracterizado por dos estados: el primero es biosintético y el segundo es degradativo con un efecto más profundo en la luz que en la oscuridad. El análisis de los datos por regresión multilinear fue también empleado para simular los resultados, especialmente los cambios en carotenoides totales como una función del tiempo. La evaluación sensorial para el color de las muestras indicó una larga variación en respuestas de los panelistas. Se recomendaron tratamientos a baja temperatura para favorecer la calidad del pimentón si es reducida la velocidad de formación de compuestos de pardeamiento

Designing chitosan-tripolyphosphate microparticles with desired size for specific pharmaceutical or forensic applications

Chitosan (CS) is a natural cationic polymer obtained by the partial N-deacetylation of chitin. Chitosan microparticles can be prepared by cross-linking with tripolyphosphate (TPP) via the ionic interaction between positively charged amino groups (CS) and negatively charged counter ions (TPP). This can be controlled by the charge density of CS and TPP, which depend on the pH and ionic strength of the solution. The purpose of this study is to investigate the combined effects of three independent variables (pH, ionic strength and CS: TPP ratio) on three important physico-chemical properties (viscosity, zeta potential and particle size) during the preparation of microparticles. CS: TPP microparticles were prepared using experimental design and equations were generated and used to predict relative viscosity, zeta potential and particle size under different conditions. This gives us the ability to design tuneable CS-TPP microparticles with desired size for specific pharmaceutical or forensic applications e.g. latent fingerprint visualisation

Anaerobic up flow fluidized bed reactor performance as a primary treatment unit in domestic wastewater treatment

The fluidized bed UASB performance was studied in this experiment as a primary unit the anaerobic unit the advantage of better generated sludge characteristics and smaller tank volume. The reactor performance was investigated for the treatment of domestic wastewater with unexpected industrial water flows at different operational temperatures (14–25 °C) and loading rates. For each temperature range the reactor performance was studied under different hydraulic loadings HRT (6, 4, 2.5 h). The best methane yield rate and COD total removal rate are 0.285 l/g COD total and 70.82% respectively at warm working temperature 19 °C with OLR 7.76 kg COD/m3/day and HRT 6 h. On the low temperature operation, the average COD removal of the reactor was 55.28% and 50.33% for HRT of 4 h and 2.5 h respectively. The methane production dropped to 0.1623 & 0.0988 L CH4/g COD with average organic loading rate of 5.34 & 10 kg COD/m3/day for HRT of 4 h and 2.5 h respectively. The efficiencies of Total nitrogen removal ranged between 2.23 and 10.83% with an apparent decrease during the low temperature high rate stages. Nitrite removal was in the range of (23.08–77)% with up to the 2 mg/L in the effluent water when obtaining high organic loading and warm temperature. These results demonstrated that the domestic wastewater could be anaerobically treated in a fluidized bed UASB reactor with very low HRT reaching 2.5 h

Performance appraisal of the A2/O process in domestic wastewater treatment replacing the anaerobic unit with UASB

Feasibility of a combined system consisting of an anaerobic up-flow anaerobic sludge blanket (UASB) followed by anoxic unit then aerobic activated sludge (AS) was investigated. The system was fed with normal domestic wastewater, then medium loading wastewater using activated sludge from El Berka WWTP, then high strength sewage having a chemical oxygen demand (COD) of 2635 mg COD/L. The organic loading rate (OLR) was increased gradually from 0.5 to 4.43 kg COD/m3/day. The HRT was changed for each loading from 10.5 to 15 h. The internal recirculation (IR) was tested at 100%, 200% and 300% for each loading run. The return activated sludge was adjusted to maintain a mixed liquor suspended solids of greater than 2500 ppm. At steady state conditions, the UASB reactor achieved removal efficiency up to 79.13% of the total COD. The combined system performed an excellent organic removal pushing the overall removal efficiency of the total COD, TN and TP to 95.87%, 84.95% and 87.59%, respectively. When the OLR increased to 4.43 kg COD/m3/day, the effluent quality of the UASB deteriorated reaching a percent of 48.20 for COD removal efficiency dropped to 62.90%, 29.90% and 46.90% respectively. The optimum operational conditions for the system on different organic loadings were HRT = 15 h and the IR = 200%

Aeromycobiota of Western Desert of Egypt

The prevalence of airborne mycobiota at six different regions of Western desert (5 regions) and Eastern desert (1) of Egypt was determined using the exposed-plate method. A total of 44 genera, 102 species and one variety in addition to some unidentified yeasts and dark sterile mycelia were collected. Of the above, only 5 species were isolated from the 15 exposures (5 plates each, 30 minutes exposure) at different localities in Eastern desert. However, all of the isolated fungi except Ulocladium tuberculatum were recovered from the 5 regions surveyed at Western desert, with the most dominant being species of Aspergillus and Alternaria. Aspergillus fumigatus, A. niger and Alternaria alternata were the most commonly encountered species. Other fungi were also reported as dominant from one or more regions such as yeasts, and/or Mycosphaerella, Cladosporium, Penicillium, Cochliobolus, Ulocladium and Pleospora while retreated in other(s). The highest number of both genera (29), species (57 + 1 variety) and the total fungal catches (1987 propagules/ 15 exposures) were recorded in the atmosphere of Kharga Oasis, while the least being recorded along the road from Cairo to Burg El-Arab via Alexandria (18 genera, 26 species and 349 catches) or Farafra Oasis (21 genera, 32 species and 343 catches). This pattern seems to be correlated to the human population and activities, the vegetation areas and/or environmental conditions, where the higher human population and larger vegetation areas, the higher fungal population and diversity and vice versa. Key words: airspora, Eastern desert, Egypt, fungi, Oases. (Af. J. of Science and Technology: 2002 3(1): 1-9

Comparison of early effects of right ventricular apical pacing on left ventricular functions in single and dual chamber pacemakers

Objectives: Our study aimed to demonstrate the early negative impact of right ventricular apical pacing induced by single (VVI) and dual chamber (DDD) pacemakers on LV functions in patients with preserved EF. And to assess that single brain natriuretic peptide (BNP) after 2 months of implantation is correlated to ventricular dyssynchrony. Methods: 40 patients with implanted VVI and DDD pacemakers were examined before implantation and again after 2 and 6 months of implantation for BNP, left ventricular (LV) systolic and diastolic functions by echocardiography and pulsed tissue Doppler. After 6 months, patients with DDD pacemakers were crossed over to VVI mode of pacing for 2 weeks with lower rate programed to 60 beat per minute then sample for BNP was collected again. Results: There was no statistically significant difference in LV systolic and diastolic functions except for myocardial performance index (MPI) with (P value of 0.03). Mean BNP level in VVI pacing was higher than DDD pacing after two months with P value = 0.001 while comparison after 6 months showed P value = 0.023. There was a statistically significant difference between both groups in results of aortic preejection delay (APED) (P value of <0.05). BNP was correlated to APED (r = 0.651 and P value = 0.001) and pacing percentage (r = 0.687 and P value = 0.00). Conclusion: Loss of atrioventricular synchrony in VVI mode leads to a significant difference in LV dyssynchrony between both groups. BNP level is correlated to LV dyssynchrony and pacing percentage