EFFET DU REVÊTEMENT ET DES PARAMÈTRES DE COUPE SUR LA RUGOSITÉ DE SURFACE EN TOURNAGE À SEC DE L'ACIER 42CrMo4.

Dans ce document, une étude expérimentale est réalisée afin d'évaluer l'effet des paramètres de coupeet le matériau de revêtement sur les performances des outils de coupe en tournage de l'acier 42Cr Mo4. Une étude comparative a été réalisée entre deux outils en carbure non revêtu et revêtu avec une couche de revêtement Al2O3/TiCN,Lesoutils de coupe ayant la même géométrie. Dans cette étude nous avons utilise la  méthodologie de surface de réponse  applique  à un plans  d'expérience de taguchi (09 essais ), dont les paramètres  d'entrée  sont : la vitesse de coupe, la profondeur de passe et l'avance par tour. Le procédé ANOVA a été utilisée pour quantifier les effets des paramètres de coupe sur l'usinage des surfaces.L'effet des couches de revêtement sur la qualité de surface est également étudié. les résultats  montrent  que  l'avance  a une grande influence sur la rugosité  de surface (Ra) et on observe qu'une plus faible rugosité de surface est obtenue lors de l'utilisation de  (Al2O3/TiCN) plaquette revêtue.Mots Clés:Outil De Coupe, Revêtements Durs, RSM, Rugosité de surface, Caractérisation de Revêtement

Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio

Influence of crop residue ration supplementation on the attainment of puberty and postpartum reproductive activities of Red Sokoto goats

The general objective of this study was to come up with an appropriate, affordable and locally available crop residue supplementation package that would enhance reproductive performance in small ruminants. Specifically, 28 Red Sokoto weaner does between 3 and 4 months of age weighing between 2 and 3 kg were used in the first experiment to determine the influence of crop residue supplementation on age and weight at puberty as determined by blood progesterone levels. In the second experiment, another 28 adult does (equal to or greater than 2 years old) of the same breed in the same flock with lactation numbers between 1 and 3 were used to determine the length of postpartum acyclic period. In both experiments, a 3 x 2 factorial experimental design comprising three dietary supplements (A, B, C) at two feeding levels (1% and 2% of body weight) fed in addition to a basal diet of Digitaria smutsii hay and natural pasture ad libitum with an unsupplemented negative control group (D) and four goats per treatment was utilized. In ration A, a conventional concentrate supplement consisting of maize, wheat offal, cottonseed cake and bonemeal was utilized; in rations B and C, the supplement consisted of guinea-corn bran, cowpea husk and groundnut haulms; and maize offal, groundnut shells and groundnut haulms respectively. Unsupplemented (ration D) weaner does reached puberty at a later age and had lighter body weights than all the others. Weaner does on ration 2A (concentrate fed at 2% of body weight) attained puberty at the earliest age and heaviest body weight, although the age at puberty was not significantly different from those on rations 1A (concentrate fed at 1% body weight), 1C and 2C. Blood progesterone profiles before and after puberty ranged from 0.05 to 9.0 ng/ml, respectively, and was highest in does fed rations A and C and least in the unsupplemented does. The mean interval between kidding and initiation of ovarian activity was 54.28 plus or minus 17.61 days and the mean interval between kidding and conception was 63.04 plus or minus 25.34 days. Only 25% of the unsupplemented does conceived again during the period under study compared with 100% in rations 1A, 2A, 1C and 2C; 75% in ration 2B and 50% in ration 1B. It was concluded that implementation of supplementary feeding in the dry season improves reproductive performance in the Red Sokoto doe. Furthermore, ration C, a crop residue-based ration, was a suitable dry season supplementation alternative to the expensive conventional concentrate ration for the smallholder goat farmer in the subhumid tropics of Nigeria

Disposable sensors in diagnostics, food and environmental monitoring

Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities

Modelling the trident SME-bank relationship

Relationship banking (RB) with SMEs has been approached as a one-size-fits-all where no differences exist between micro, small, and medium businesses. Nevertheless, recent research has clearly identified three distinct levels of RB depending on variables such as the size and complexity of the business and the amount of borrowing. In this study, we create an original model of this fundamental trident, presented as a system of postulates and inferences in mathematical terms, to capture the structure and dynamics of the three RB levels from the supply/bank side. The model systematically shows the existence of and describes the three RB levels. Further, it highlights how each of these levels is dependent on the determinant variables and how a comparison between the three levels is possible based on the per-capita contribution of each of the determinant variables, in turn, to the per-capita RB service production. Our model provides an analytical framework that can assist banks and researchers to rigorously assess and study each level separately or in comparison to the others. It is also beneficial as it can be used to calculate the optimal allocation of the bank's limited resources among the three levels of RB and to achieve maximum value creation for all stakeholders

Ultrafiltration and reverse osmosis in unstirred batch cell of charged solutes (protein, salts) with total retention

International audienc

Sheep production on medic and weedy pasture in semi-arid Morocco

Most farms in the semi-arid region of Morocco are mixed cereal-livestock producers. Livestock, dominated by sheep, account for more than one third of farm income but production is far below potential. Low quality cereal straw and weeds from fallow land are the main sources of forage, but provide inadequate nutrition. Fall planted wheat is usually grown in rotation following a year of weedy fallow. The replacement of the weedy fallow by sowing a self regenerating annual Medicago spp., a system known as ley farming in Australia, was tested in Morocco to determine if it could increase livestock production. Ewe and lamb liveweight gain, wool yield, and forage standing crop during grazing were compared between medic and weedy fallow pastures. Large significant differences (P < 0.05) in forage standing crop and both lamb and ewe liveweight gain occurred in 1990/91 but no differences occurred the previous 2 years when medic was initially sown nor the following 2 years during severe drought. In 1991 lambs gained 67% and ewes gained 60% more liveweight, plus wool yield was 23% higher on medic as compared to weedy fallow. In addition, 3,000 kg ha-4 of forage remained after grazing medic as compared to 568 kg ha-1 after weedy fallow.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Environmental and genetic effects on growth in Timahdite and crossbred lambs in Morocco

Knowledge of genetic parameters for growth traits of economic importance is required for the development of sheep populations in Morocco. Records on 544 lambs of the Timahdite (T) breed and of 756 D'man x Timahdite (DT) lambs, all born from 1992 to 1998, were used to estimate genetic parameters for lamb weights at birth, at 30, 70 and 90 days and daily gains from 10-30 days, 30-70 days and 30-90 days for each trait. Separate REML (co)variance component estimates were obtained assuming animal models that included the fixed effects of birth year, sex, age of dam, birth type or rearing types and the interaction of birth year by sex, the animal direct genetic effect and the maternal genetic effect. Genetic and phenotypic correlations between traits were estimated with models including the same fixed effects and only additive direct genetic effects. All fixed effects influenced growth traits. The direct heritability estimates for the various body weight and daily gain traits were low to medium and varied between 0.07 and 0.25 in T, and between 0.02 and 0.18 in DT. Maternal heritability ranged from 0.20 to 0.36 in DT, and from 0.01 to 0.10 in T lambs, except for the birth weight (0.53). For all traits the direct and maternal genetic correlations were high and negative in DT (-0.80 and -1.00) and in T (-0.90 and -1.00) lambs. However, the accuracy of such estimates is low due to the small data set used in the present study. The estimates of genetic and phenotypic correlations were positive for all traits, they were particularly high for genetic correlations between weights and weight gains after birth, both in DT and T lambs, and they showed no genetic antagonisms among the growth traits