Lipid Composition and State of Oxidation of Fortified Infant Flours in Low‐Income Countries Are Not Optimal and Strongly Affected by the Time of Storage

Food fortification is widely used to address the public health problem of nutrient deficiencies. This study's purpose is to assess the lipid profile and nutritional quality of 13 fortified infant flours (FI) collected “in the field” in Africa and Asia after different periods of storage. The lipid content, fatty acid profiles, lipophilic vitamin content, and lipid oxidation state (peroxide values, secondary oxidation products) are determined. Mycotoxins and packaging materials are also characterized. The lipid content averages 9.1 ± 3.5 g/100 g. Fatty acid profiles are dominated by linoleic (43.3 ± 8.8%), oleic (29.5 ± 7.4%), and palmitic acid (17.8 ± 6.7%) and result in an average ω6/ω3 ratio of 12.2 ± 5.9 but with high values for some FI. Very high overages in vitamins A, D, and E are observed in products stored for short periods (1–6 months), whereas FI stored for more than 12 months has insufficient vitamin content. Lipid oxidation is acceptable but for six products presenting excessive peroxide values. Most products are contaminated by low amounts of mycotoxins but only two FI do not abide by the regulation. A strong correlation between peroxide values, hexanal content, and time of storage is observed. Practical Applications: The expiration dates for FI commercialized in low‐income countries should be shortened from 36 to 12 months so as to guarantee their nutritional quality of these functional foods and to abide by the fortified infant flour legislation. Indeed, FI quality significantly decreases over time of storage. The use of high barrier packaging materials must be generalized, although it is a necessary criterion but not sufficient to ensure the long‐term stability of FI. Special attention should be given to reduce lipophilic vitamin overages and to improve their lipid profile, especially the ω6/ω3 ratio, which has to be lower than 15.     

Selective silicon epitaxial growth on a submicrometer WSi2 grating: Application to the permeable base transistor

We report the silicon epitaxial growth on top of a tungsten disilicide grating using a rapid thermal processing, low pressure chemical vapor deposition reactor. The epitaxial growth of silicon is shown to proceed two dimensionally from the Si surface without reaction with the underlying WSi₂ grid. Both lateral diffusion over WSi₂ of Si adsorbed species and vertical diffusion of Si through the silicide film are shown to occur with respective weight depending on the width of the WSi₂ lines. This allows silicon selective growth on patterned Si/WSi₂ structure for grating periodicity below 1 μm. Preliminary electrical measurements of the Si/WSi₂/Si overgrown permeable base transistor (PBT) thus fabricated are presented, showing current densities J_max of up to 6000 A/cm² and transconductancesg _m of 5 mS/mm.     

Analytic modeling, optimization, and realization of cooling devicesin silicon technology

A novel cooling device fully built in silicon technology is presented. The new concept developed in this work consists of micromachining the bottom side of the circuit wafer in order to embed heat sinking microchannels directly into the silicon material. These microchannels are then sealed, by a direct wafer bonding procedure, with another silicon wafer where microchannels and inlet-outlet nozzles are micromachined too. A cooling fluid (water) is then forced through the array of channel to convey heat outside the chip. Such a configuration presents advantages to provide a significant reduction of the cooler overall dimensions, to reduce the number of the involved materials and to be compatible with integrated circuit fabrication procedures, In this study analytical tools were used in order to get a global evaluation of all the thermal resistances characteristic of such devices. Using these adequate analytic models with appropriate approximations, a global optimization procedure was then applied and led to the definition of he optimum dimensions of the silicon micro heat sink. The realization procedure was then carried out in a clean room environment. First experimental characterization results obtained from the earlier prototypes demonstrated that the thermal properties of this silicon-based cooling device are satisfactory and can be reasonably compared to those of commercially available copper micro heat sinking components     

Effect of sequential ventilation on cheese ripening and energy consumption in pilot ripening rooms

The aim of this work was to enable improvements in cheese maturation through control of airflow and climatic conditions in ripening rooms, and the minimisation of energy consumption using sequential ventilation. Sensors and advanced software were installed to monitor and control pilot scale ripening chambers of 12.3 and 4.2 m³. Techniques in computational fluid dynamics were used to improve the ventilation uniformity and level around the cheeses. The initial chamber (12.3 m³) was modified by reducing the room length from 3.2 to 1.1 m by changing the location of the wall in front of the cheese stack, altering the location of the two fans and varying their flow rate from 160 to 250 m³ h^?1. Sequential ventilation (1/3 of ripening time) did not significantly affect the respiratory activities, microbiological, physico-chemical or sensory characteristics of ripened, pressed, non-cooked cheeses, but it did lead to a reduction in energy consumption of approximately 18%.     

A test procedure to characterise the heating performance of domestic microwave ovens

A test procedure has been developed and used to characterise the performance of domestic microwave ovens in relation to the heating of chilled ready meals. The procedure uses reproducible test loads, which simulate the heating and weight loss characteristics of a chilled ready meal under consumer use. The temperature distribution after heating from 5 °C to a defined minimum temperature of 70 °C is measured in the food simulant using a purpose designed multipoint thermocouple ‘hedgehog’ probe. The temperature, weight loss and heating time data from the test are entered into a spreadsheet analysis program, which provides a simple oven performance ‘score’ and/or comprehensive heating performance data.     

Operation of a Self-Controlled Synchronous Motor Without a Shaft Position Sensor

The starting operation of a self-controlled synchronous motor without a shaft position sensor is studied. A method which permits the determination of the rotor position at a standstill by voltage sensing is explained. Various forced commutation techniques and starting, strategies are considered. Torque characteristics for natural commutation operation are studied, providing simple formulas with good precision. Experimental results obtained with a prototype drive system are given.     

A Self-Controlled Synchronous Motor Drive using Terminal Voltage System

A current-fed self-controlled synchronous motor drive is described, in which the motor terminal voltage is used to synchronize the inverter triggering pulses. Power-factor optimization control strategy is studied, and its implementation in a microprocessor-based control system is described. Analysis of the z-domain using linearized models for system components is presented. Experimental results are given.     

Evidence for a dynamic cycle between Mn and Co in the water column of a stratified lake

The geochemical behavior of Co in aquatic systems has often been related to the presence of Fe and Mn particles. A few studies have shown that Co is exclusively associated with particulate Mn, but the dynamics of Co and Mn cycling have never been determined in real time under natural conditions. In this study, we used a combination of analytical techniques to study the temporal and spatial evolution of Mn microparticles (MnOx) over 2 weeks in the water column of a shallow stratified lake (Paul Lake, MI). We report a temporal accumulation of dissolved Mn at the oxic-anoxic transition, and we show that this accumulation is due to the reductive dissolution of Mn particles. The reductant has not been identified, but abiotic reduction by sigmaH2S and ferrous iron is excluded because they are produced below the zone of MnOx reduction. Hybridization of RNA isolated from Paul Lake with oligonucleotide probes targeting the delta proteobacteria, which include metal-reducing species, suggests that their activity is greatest at and just below the oxic-anoxic transition, so that Mn reduction may be influenced by bacterial activity. Mn-oxidizing bacteria were isolated from this zone as well. We also demonstrate that the dynamic evolution of MnOx has a direct influence on the distribution of Co in the water column of this lake: dissolved Co is released during the reductive dissolution of MnOx and accumulates at the redox interface.     

Evaluation of disintegrants functionality for orodispersible mini tablets

Objective: This work evaluates the functionalities of different superdisintegrants (SD) for manufacturing orodispersible mini tablets (ODMT) by direct compression.

Methods: Twenty-three formulations varying in SD type, concentration, and lubricant were used to manufacture ODMT. The ODMT were then characterized for the following properties: friability, porosity, tensile strength, in vivo and in vitro disintegration time (DT).

Results: The results show that the presence, type, and concentration of SD did not influence friability, porosity, or tablet tensile strength. With regards to in vivo DT, only cross-linked poly (vinyl pyrrolidone) improved DT in all the tested formulations. Results also showed that when using microcrystalline cellulose (MCC) above 20% in the formulation, DT is longer. Cross-linked carboxymethyl cellulose accelerates DT when the MCC content is less than 20%. As for cross-linked carboxymethyl starch and calcium alginate showed no improvement on DT. Results for in vitro DT were all shorter than in vivo results and there was no correlation with the in vivo evaluation.

Conclusions: This study shows that there is a need to develop better in vitro testing that precisely simulates in vivo conditions and that are adapted to ODMT. This standardization of the test methods for ODMTs must be accompanied by an improvement in the comprehension of SD mechanisms.