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1.
Ultrason Sonochem ; 54: 48-60, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30827903

ABSTRACT

A green and innovative method, manothermosonication (MTS), for proteins extraction from dry Arthrospira platensis cyanobacteria assisted by ultrasound was designed in this work. Manothermosonication (probe, 20 kHz) was compared to a conventional process performed in the same conditions without ultrasounds. The extraction was carried out with a continuous flow rate at 15 mL/hour. Extraction parameters were optimized using a central composite design. Moreover, mathematic modelling and microscopic investigations were realized to allow a better understanding of ultrasound physical and structural effects on spirulina filaments and mass transfer phenomena over time. Crude extract and sections stained with toluidine blue were analyzed with optical and scanning electron microscopies. According to experimental results, MTS promoted mass transfer (high effective diffusivity, De) and enabled to get 229% more proteins (28.42 ±â€¯1.15 g/100 g DW) than conventional process without ultrasound (8.63 ±â€¯1.15 g/100 g DW). With 28.42 g of proteins per 100 g of dry spirulina biomass in the extract, a protein recovery rate of 50% was achieved in 6 effective minutes with a continuous MTS process. Microscopic observations showed that acoustic cavitation impacted spirulina filaments by different mechanisms such as fragmentation, sonoporation, detexturation. These various phenomena make extraction, release and solubilization of spirulina bioactive compounds easier.


Subject(s)
Bacterial Proteins/isolation & purification , Chemical Fractionation/methods , Industry , Models, Theoretical , Spirulina/chemistry , Ultrasonic Waves , Amino Acids/analysis , Bacterial Proteins/chemistry , Chemical Fractionation/instrumentation , Feasibility Studies , Green Chemistry Technology , Kinetics , Temperature
2.
Environ Technol ; 40(19): 2513-2526, 2019 Aug.
Article in English | MEDLINE | ID: mdl-29464994

ABSTRACT

Several automatic strategies for aeration control have been investigated so far to favor a significant decrement of energy consumptions in biological processes in wastewater treatment plants (WWTPs). Above all, the intermittent aeration process has demonstrated to have several advantages. This work reports the results of a case study made in a small municipal WWTP where an intermittent aeration control strategy based on the online measurement of real-time nitrogen forms has been implemented to optimize the nitrogen removal and the energy consumption in an activated process. High organic removal efficiency was achieved during the whole experimental period. Results indicated that nitrogen removal efficiency has been improved, especially during winter months, by the control strategy adopted that helped to determine the perfect length for the nitrification and denitrification phases. The intermittent aeration process increased the activity of the biomass, further selecting phosphate-accumulating bacteria and improving the growth of bacteria able to internally store carbon source. Excellent effects were achieved on energy and chemical consumption, with a reduction of about 15% and 23%, respectively. Finally, a 12% reduction of sludge production was also detected.


Subject(s)
Denitrification , Nitrogen , Bioreactors , Nitrification , Waste Disposal, Fluid , Wastewater
3.
Ultrason Sonochem ; 37: 216-221, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28427626

ABSTRACT

Manothermonication is a recognized and efficient method used for sterilization in food preservation. The synergistic effect of sonication combined with pressure and temperature allows enhancing the cavitation activity. Never employed for extraction, this study is about the transposition of this process as a tool of extraction. In this study, Rhodosporidium toruloides yeast was submitted to extraction by four modes of sonication, with a temperature ranged from 20 to 55°C and a pressure between 1 to 2bars. The lipids extraction yields were compared to the conventional maceration. Microbial oils obtained from both processes were analyzed and quantified by HPTLC (High Performance Thin-Layer Chromatography) and GC-FID (Gas Chromatography with flame ionization detector) after transesterification of lipids. Manothermosonication (30min, 2bars, 55°C) permits to enhance of approximately 20% the extraction yield of lipids to compared to conventional maceration. The fatty acid profiles of each pretreatment and extraction by US, MS, TS and MTS do not affect the fatty acid profiles of yeast (majority of oleic acid (C18:1n9), linoleic acid (C18:2n6) and palmitic acid (C16:0)). Manothermosonication technique shows a great potential for lipid extraction from oleaginous microorganisms.


Subject(s)
Chemical Fractionation/methods , Lipids/isolation & purification , Sonication/methods , Temperature , Ustilaginales/chemistry , Fatty Acids/chemistry , Lipids/chemistry , Time Factors
5.
N Engl J Med ; 358(5): 484-93, 2008 Jan 31.
Article in English | MEDLINE | ID: mdl-18184950

ABSTRACT

BACKGROUND: Estimates of the death toll in Iraq from the time of the U.S.-led invasion in March 2003 until June 2006 have ranged from 47,668 (from the Iraq Body Count) to 601,027 (from a national survey). Results from the Iraq Family Health Survey (IFHS), which was conducted in 2006 and 2007, provide new evidence on mortality in Iraq. METHODS: The IFHS is a nationally representative survey of 9345 households that collected information on deaths in the household since June 2001. We used multiple methods for estimating the level of underreporting and compared reported rates of death with those from other sources. RESULTS: Interviewers visited 89.4% of 1086 household clusters during the study period; the household response rate was 96.2%. From January 2002 through June 2006, there were 1325 reported deaths. After adjustment for missing clusters, the overall rate of death per 1000 person-years was 5.31 (95% confidence interval [CI], 4.89 to 5.77); the estimated rate of violence-related death was 1.09 (95% CI, 0.81 to 1.50). When underreporting was taken into account, the rate of violence-related death was estimated to be 1.67 (95% uncertainty range, 1.24 to 2.30). This rate translates into an estimated number of violent deaths of 151,000 (95% uncertainty range, 104,000 to 223,000) from March 2003 through June 2006. CONCLUSIONS: Violence is a leading cause of death for Iraqi adults and was the main cause of death in men between the ages of 15 and 59 years during the first 3 years after the 2003 invasion. Although the estimated range is substantially lower than a recent survey-based estimate, it nonetheless points to a massive death toll, only one of the many health and human consequences of an ongoing humanitarian crisis.


Subject(s)
Mortality , Violence/statistics & numerical data , Warfare , Adolescent , Adult , Age Distribution , Cause of Death , Child , Cross-Sectional Studies , Female , Health Surveys , Humans , Iraq/epidemiology , Male , Middle Aged , Monte Carlo Method , Surveys and Questionnaires
6.
J Chromatogr A ; 1085(2): 224-9, 2005 Sep 02.
Article in English | MEDLINE | ID: mdl-16106702

ABSTRACT

A simple and rapid HPLC method has been developed for simultaneous determination of the four resveratrol forms (aglycon and glycosidic) in a Grenache wine from Châteauneuf du Pape (Vaucluse). These analyses were achieved by using two commercial monolith HPLC columns and diode array detection. The method provided reliable separations at low pressure with a short analysis time. The limit of detection (LD) and limit of quantification (LQ) were calculated for each standard. The molecules were separated and quantified in a single run without any purification of the sample.


Subject(s)
Chromatography, High Pressure Liquid/methods , Glucosides/analysis , Stilbenes/analysis , Wine/analysis , Chromatography, High Pressure Liquid/instrumentation , Glucosides/chemistry , Resveratrol , Stereoisomerism , Stilbenes/chemistry
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