Université Nantes Angers Le Mans

About: Université Nantes Angers Le Mans is a education organization based out in Nantes, France. It is known for research contribution in the topics: Geology & Finite element method. The organization has 434 authors who have published 249 publications receiving 7208 citations. The organization is also known as: PRES Universite Nantes Angers Le Mans.

Impact of Pregelatinized Starches on the Texture and Staling of Conventional and Degassed Pound Cake

Abstract: The influence of selected pregelatinized starches on staling of pound cake has been investigated considering wheat and maize pregelatinized starches as flour substitutes. Two baking systems were considered to assess staling: a miniaturized baking system providing degassed baked batter and a conventional oven providing real products. Texture profile analysis, compression, and rupture tests were used to follow texture evolution during storage. Results confirmed the positive effect of partial substitution by pregelatinized starches in microcakes on retarding staling, while the denser structure of pregelatinized starch cakes prevented the same positive impact on texture and staling.

Mutual Legume Intercropping for Forage Production in Temperate Regions

Abstract: Carefully designed intercropping systems can have many advantages in comparison to monocropping such as increased forage yield, enhanced weed control, reduced soil erosion and, in the case of legumes, improved soil fertility due to their symbiosis with nitrogen-fixating bacteria. In addition the use of forage legumes is increasing for the rations of ruminants because legumes supply animal husbandry with protein-rich diets. Due to lower forage yield from perennial legumes in the first planting year and a critical standing ability of annual forage legumes, farmers tend to establish these crops with a companion crop. The first trials in Serbia studied the role an annual legume in the establishment of a perennial legume. Field pea cultivars with reduced plant height, semi-leafless leaf types and improved lodging tolerance were included together with a pure red clover stand and its mixture with oats as controls. When sown as the companion crop an annual forage legume can provide an economic yield during the perennial forage crop establishment. In average, field pea as a companion crop increases forage annual dry matter yield by 2.56 t ha − 1 and reduces weeds in red clover stand by 29%. Another group of trials involved mixtures of autumn-sown cool season, spring-sown cool season and warm season annual legumes for forage production. Here one plant had good and another poor standing ability and with concurring development stages and similar growth habit. There were economically justified intercrops with Land Equivalent Ratio (LER) values of forage dry matter yield higher than 1, such as winter faba bean with winter common vetch (1.42), spring faba bean with spring grass pea (1.44) and pigeon pea with lablab bean (1.12). The achieved results in the mutual legume intercropping research in Serbia encourage the similar research in the neighbouring West Balkan Countries and other European temperate regions.

Risk factors for Raynaud's phenomenon in the workforce

Abstract: Objective To assess the prevalence of and risk factors for Raynaud's phenomenon (RP) in a French working population characterized by various levels of exposure to work-related constraints. Methods The study population comprised 3,710 workers (2,161 men and 1,549 women) who were followed up by 83 occupational physicians and were representative of the region's workforce. RP, as diagnosed by a questionnaire and a standardized interview, was defined as the occurrence of at least occasional attacks of finger blanching triggered by exposure to environmental cold during the previous 12 months. Personal factors and work exposure were assessed by self-administered questionnaires. The associations between RP and personal and occupational factors were analyzed using logistic regression modeling. Results A total of 87 cases of RP (56 women and 31 men) were diagnosed. The population-based annual prevalence rates of RP were 3.6% (95% confidence interval [95% CI] 2.7–4.5%) for women and 1.4% (95% CI 0.9–1.9%) for men. Women had a higher risk of RP (odds ratio [OR] 2.1 [95% CI 1.3–3.4]) and the risk decreased continuously with body mass index (OR for 1-kg/m2 increment 0.87 [95% CI 0.81–0.94]). The risk of RP increased consistently but moderately with age after 35 years (ORs ranging from 2.0 [95% CI 1.1–3.8] to 2.9 [95% CI 1.6–5.2]). Among the work-related factors studied, RP was associated with an exposure to a cold environment or objects (OR 2.2 [95% CI 1.0–4.6]), a high repetitiveness of a task (OR 1.7 [95% CI 1.0–2.7]), a high psychological demand at work (OR 1.7 [95% CI 1.0–2.7]), and low support from supervisors (OR 2.4 [95% CI 1.5–3.8]). Conclusion Personal and work-related factors were associated with RP, with a clear difference between the sexes. Work-related psychosocial stressors played a significant role independently of biomechanical and environmental exposure.

Evaluation of crack status in a meter-size concrete structure using the ultrasonic nonlinear coda wave interferometry

Abstract: The field of civil engineering is in need of new methods of non-destructive testing, especially in order to prevent and monitor the serious deterioration of concrete structures. In this work, experimental results are reported on fault detection and characterization in a meter-scale concrete structure using an ultrasonic nonlinear coda wave interferometry (NCWI) method. This method entails the nonlinear mixing of strong pump waves with multiple scattered probe (coda) waves, along with analysis of the net effect using coda wave interferometry. A controlled damage protocol is implemented on a post-tensioned, meter-scale concrete structure in order to generate cracking within a specific area being monitored by NCWI. The nonlinear acoustic response due to the high amplitude of acoustic modulation yields information on the elastic nonlinearities of concrete, as evaluated by two specific nonlinear observables. The increase in nonlinearity level corresponds to the creation of a crack with a network of microcracks localized at its base. In addition, once the crack closes as a result of post-tensioning, the residual nonlinearities confirm the presence of the closed crack. Last, the benefits and applicability of this NCWI method to the characterization and monitoring of large structures are discussed.

Influence of angularity of coarse fraction grains on internal erosion process

Abstract: This paper deals with suffusion process also named internal instability, which takes place inside the soil skeleton. In this process, finer particles of a soil migrate within its own pore spaces. These fine particles can be cohesionless particles or clay particles. With the objective to study the effect of angularity of coarse fraction grains on suffusion a series of tests was performed on different clayey sand. Three coarse fraction type samples were tested which are different by the grain size distribution and also by the angularity of grains. A specific triaxial device was used in order to force fluid through the samples in downward direction under constant hydraulic gradients.It is shown that the angularity of coarse fraction grains may contribute to increase the erosion resistance of the tested soils by a factor of 5. Moreover for the tested soils, the grain shape has an effect on hydraulic conductivity decrease. The angularity of coarse fraction grains may intensify the geometric blocking of detached clay particles.Finally a study is conducted to compare the different ways to characterize the angularity of grains: by an analysis of grain pictures, by using an angulometer or by measuring the internal friction angle.