Measurement of the acoustic absorption coefficient of some local building materials for residential buildings using the Kundt tube method

Sound noise is a major societal problem, whose health, environmental and even economic impact is very important. According to the World Health Organization (WHO), noise is an acoustic phenomenon that produces an uncomfortable hearing sensation. Populations whose buildings are housed in areas at high risk of noise are exposed to multiple diseases resulting from noise pollution. To remedy this, it is important to think of choosing the right materials with higher acoustic absorption coefficient. The materials studied in this article are concrete, mortar, stabilized soil, which are commonly and most used materials in the construction of residential buildings. The present work consists of determining the sound absorption coefficient of each material indexed by the Kundt tube method in order to provide building technicians with the standards to be followed to improve the acoustic comfort of residential buildings. From the results obtained in this paper, it’s obvious sound absorption coefficients peaks in the low frequencies between 100 Hz and 500 Hz for the three materials. These sound absorption coefficients peaks are accented respectively at 0.74 for the stabilized earth; 0.85 for mortar and 0.94 for concrete

Caractérisation du matériau bois de structures utilisé en construction par la méthode vibratoire : une technique de mesure non destructive

Le présent article décrit une nouvelle méthode non destructive de caractérisation des poutres de structures en bois. Basée sur l’excitation par vibrations, la méthode développée est fondée sur la théorie de Bernoulli et Timoshenko. Elle a été appliquée aux types de bois lamellé-collé, Laminated Veener Lumbers ainsi qu’aux composites en I, pour les règles de conception, de calculs de dimensionnement et de suivi de leur endommagement. Sur la base d’un vaste programme expérimental de caractérisation des poutres de ces différents types de bois, la comparaison des modules élastiques a été effectuée entre les valeurs estimées par la méthode vibratoire et celles fournies par la méthode statique fondée sur la mesure de la flèche relative. Les résultats obtenus mettent en évidence que la mesure du module d’élasticité par la méthode dynamique non destructive proposée peut être retenue pour caractériser les poutres en vue de la détermination des niveaux de charge des essais de comportement différé et de la durée de vie, deux facteurs phénoménologiques très importants qui, à ce jour, ne sont pas assez clarifiés dans les règles régissant les calculs des poutres à base de bois de grandes dimensions.Mots-clés : vibrations, poutres de structures, durée de vie, flexion circulaire.Characterization of structural wooden beams by vibratory method : a nondestructive technique of measurement This paper describes a new non-destructive characterization method for structural wooden beams. Based on vibrations exciting, the developed method is based on Bernoulli and Timoshenko theory. It has been applied to the lamellate-stuck types, Laminated Veener Lumbers and I composites types, for their design rules, calculations and damage monitoring. Based on an extensive experimental program of beams characterization for such different wood types, comparison of elastic modulus was made between estimated values from vibrations method and those provided by the static method funded on relative arrow or flitch measurement. The obtained results show that elasticity modulus measurement with the proposed nondestructive dynamic method can be used for wood beams characterization, in view of determination of loading levels during delayed behavior testing and lifespan studying, two very important phenomenological factors that, to date, are not sufficiently clarified in the governing rules for larger wood beams calculation.Keywords : vibrations, structures’ beams, lifespan, circular bending

A multidrug approach to modulate the mitochondrial metabolism impairment and relative oxidative stress in fanconi anemia complementation group a

Fanconi Anemia (FA) is a rare recessive genetic disorder characterized by aplastic anemia due to a defective DNA repair system. In addition, dysfunctional energy metabolism, lipid droplets accumulation, and unbalanced oxidative stress are involved in FA pathogenesis. Thus, to modulate the altered metabolism, Fanc-A lymphoblast cell lines were treated with quercetin, a flavonoid compound, C75 (4-Methylene-2-octyl-5-oxotetrahydrofuran-3-carboxylic acid), a fatty acid synthesis inhibitor, and rapamycin, an mTOR inhibitor, alone or in combination. As a control, isogenic FA cell lines corrected with the functional Fanc-A gene were used. Results showed that: (i) quercetin recovered the energy metabolism efficiency, reducing oxidative stress; (ii) C75 caused the lipid accumulation decrement and a slight oxidative stress reduction, without improving the energy metabolism; (iii) rapamycin reduced the aerobic metabolism and the oxidative stress, without increasing the energy status. In addition, all molecules reduce the accumulation of DNA double-strand breaks. Two-by-two combinations of the three drugs showed an additive effect compared with the action of the single molecule. Specifically, the quercetin/C75 combination appeared the most efficient in the mitochondrial and lipid metabolism improvement and in oxidative stress production reduction, while the quercetin/rapamycin combination seemed the most efficient in the DNA breaks decrement. Thus, data reported herein suggest that FA is a complex and multifactorial disease, and a multidrug strategy is necessary to correct the metabolic alterations

Anamorphic development and extended parental care in a 520 million-year-old stem-group euarthropod from China.

BACKGROUND: Extended parental care is a complex reproductive strategy in which progenitors actively look after their offspring up to - or beyond - the first juvenile stage in order to maximize their fitness. Although the euarthropod fossil record has produced several examples of brood-care, the appearance of extended parental care within this phylum remains poorly constrained given the scarcity of developmental data for Palaeozoic stem-group representatives that would link juvenile and adult forms in an ontogenetic sequence. RESULTS: Here, we describe the post-embryonic growth of Fuxianhuia protensa from the early Cambrian Chengjiang Lagerstätte in South China. Our data demonstrate anamorphic post-embryonic development for F. protensa, in which new tergites were sequentially added from a posterior growth zone, the number of tergites varies from eight to 30. The growth of F. protensa is typified by the alternation between segment addition, followed by the depletion of the anteriormost abdominal segment into the thoracic region. The transformation of abdominal into thoracic tergite is demarcated by the development of laterally tergopleurae, and biramous walking legs. The new ontogeny data leads to the recognition of the rare Chengjiang euarthropod Pisinnocaris subconigera as a junior synonym of Fuxianhuia. Comparisons between different species of Fuxianhuia and with other genera within Fuxianhuiida suggest that heterochrony played a prominent role in the morphological diversification of fuxianhuiids. Functional analogy with the flexible trunk ontogeny of Cambrian and Silurian olenimorphic trilobites suggests an adaptation to sporadic low oxygen conditions in Chengjiang deposits for F. protensa. Finally, understanding the growth of F. protensa allows for the interpretation of an exceptional life assemblage consisting of a sexually mature adult alongside four ontogenetically coeval juveniles, which constitutes the oldest occurrence of extended parental care by prolonged cohabitation in the panarthropod fossil record. CONCLUSIONS: Our findings constitute the most detailed characterization of the post-embryonic development in a soft-bodied upper stem-group euarthropod available to date. The new ontogeny data illuminates the systematics, trunk segmentation and palaeoecology of F. protensa, offers insights on the macroevolutionary processes involved in the diversification of this clade, and contributes towards an improved understanding of complex post-embryonic reproductive ecology in Cambrian euarthropods

A holistic multi-methodology for sustainable renovation

A review of the barriers for building renovation has revealed a lack of methodologies, which can promote sustainability objectives and assist various stakeholders during the design stage of building renovation/retrofitting projects. The purpose of this paper is to develop a Holistic Multi-methodology for Sustainable Renovation, which aims to deal with complexity of renovation projects. It provides a framework through which to involve the different stakeholders in the design process to improve group learning and group decision-making, and hence make the building renovation design process more robust and efficient. Therefore, the paper discusses the essence of multifaceted barriers in building renovation regarding cultural changes and technological/physical changes. The outcome is a proposal for a multi-methodology framework, which is developed by introducing, evaluating and mixing methods from Soft Systems Methodologies (SSM) with Multiple Criteria Decision Making (MCDM). The potential of applying the proposed methodology in renovation projects is demonstrated through a case study

Direct detection of brown adipose tissue thermogenesis in UCP1−/− mice by hyperpolarized 129Xe MR thermometry

Brown adipose tissue (BAT) is a type of fat specialized in non-shivering thermogenesis. While non-shivering thermogenesis is mediated primarily by uncoupling protein 1 (UCP1), the development of the UCP1 knockout mouse has enabled the study of possible UCP1-independent non-shivering thermogenic mechanisms, whose existence has been shown so far only indirectly in white adipose tissue and still continues to be a matter of debate in BAT. In this study, by using magnetic resonance thermometry with hyperpolarized xenon, we produce the first direct evidence of UCP1-independent BAT thermogenesis in knockout mice. We found that, following adrenergic stimulation, the BAT temperature of knockout mice increases more and faster than rectal temperature. While with this study we cannot exclude or separate the physiological effect of norepinephrine on core body temperature, the fast increase of iBAT temperature seems to suggest the existence of a possible UCP1-independent thermogenic mechanism responsible for this temperature increase

Physical and mechanical characteristics of the earthen barns used for food crop storage in the North-West of Benin (West Africa)

Atacora and Donga are two departments regarded as the barns of Benin. In these two regions, the surplus of food crops harvested by farmers is stocked in earthen barns whose primary construction material is kneaded clay soil with an admixture of vegetable straws (fonio, rice…) pounded beforehand. The following research is designed to scrutinize the variation of compression strength and/or tensile strength of the used earthen material with respect to the optimum straw content, and the fluctuation of the fracture related parameters. Laboratory tests have shown that an optimum straw content of 2% provides the highest compression strength with the best mechanical performances in terms of cohesion and internal angle of friction. Tensile strength, however, continues to increase with higher straw percentages with no breakpoint indication. Moreover, the laboratory determination of the composite material’s modulus of elasticity has proven that the used soil does not have a linear elastic behavior

Facilitates Chromatin Transcription Complex Is an “Accelerator” of Tumor Transformation and Potential Marker and Target of Aggressive Cancers

SummaryThe facilitates chromatin transcription (FACT) complex is involved in chromatin remodeling during transcription, replication, and DNA repair. FACT was previously considered to be ubiquitously expressed and not associated with any disease. However, we discovered that FACT is the target of a class of anticancer compounds and is not expressed in normal cells of adult mammalian tissues, except for undifferentiated and stem-like cells. Here, we show that FACT expression is strongly associated with poorly differentiated aggressive cancers with low overall survival. In addition, FACT was found to be upregulated during in vitro transformation and to be necessary, but not sufficient, for driving transformation. FACT also promoted survival and growth of established tumor cells. Genome-wide mapping of chromatin-bound FACT indicated that FACT’s role in cancer most likely involves selective chromatin remodeling of genes that stimulate proliferation, inhibit cell death and differentiation, and regulate cellular stress responses

Seasonal Consumptive Demand and Prey Use by Stocked Saugeyes in Ohio Reservoirs

Community structure and species composition may be strongly influenced by predator-prey interactions resulting from and leading to episodes of population abundance or scarcity. We quantified diets of stocked saugeyes (female walleye Sander vitreus × male sauger S. canadensis) and estimated biomass of their primary prey, gizzard shad Dorosoma cepedianum, in three Ohio reservoirs at quarterly intervals during July 2002-July 2003 to determine whether saugeye consumptive demand could exceed the supply of available gizzard shad prey, resulting in a shift to alternative prey. We incorporated water temperature and saugeye diet composition, growth, and mortality into walleye bioenergetics models, which allowed us to compare estimated prey-specific consumption rates by saugeyes with gizzard shad standing stocks estimated with acoustics. Spring and summer were critical seasons. During spring, gizzard shad biomass was low, saugeye consumptive demand was low, and saugeyes consumed primarily alternative prey. During summer, when age-0 gizzard shad became available as prey, saugeyes consumed similar proportions of gizzard shad and alternative prey. Saugeye cumulative consumptive demand in summer was high and approached the gizzard shad standing stock. However, during fall and winter, gizzard shad supply was adequate to support high (fall) or declining (winter) saugeye consumptive demand. Across reservoirs and seasons, saugeyes consumed alternative prey to varying degrees, primarily sunfishes Lepomis spp., yellow perch Perca flavescens, logperch Percina caprodes, and minnows Pimephales spp. Seasonal asynchrony between saugeye consumptive demand and gizzard shad biomass during spring and summer indicated that a saugeye population with high survival, growth, and consumptive demand will opportunistically increase use of prey other than gizzard shad. The manner in which saugeye predation quantitatively influences these prey species could not be assessed. However, overexploitation of gizzard shad prey appears to be unlikely at current saugeye population sizes, particularly considering the opportunistic use of alternative prey and the high reproductive potential of gizzard shad.Funding for this research was provided by the Ohio Department of Natural Resources, Division of Wildlife; Federal Aid in Sport Fish Restoration Project F-69-P, Fish Management in Ohio; and the Department of Evolution, Ecology, and Organismal Biology at The Ohio State University