Effect of temperature on the hygrothermal behaviour of unidirectional laminated plates with asymmetrical environmental conditions

2006 ◽  
Vol 72 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Z. Sereir ◽  
E.A. Adda-Bedia ◽  
A. Tounsi
Keyword(s):  
Environmental Conditions ◽  
Laminated Plates ◽  
Effect Of Temperature ◽  
Hygrothermal Behaviour

scholarly journals Whole-body imaging of neural and muscle activity during behavior in Hydra: bidirectional effects of osmolarity on contraction bursts

2019 ◽  
Author(s):  
Wataru Yamamoto ◽  
Rafael Yuste
Keyword(s):  
Nervous System ◽  
Body Size ◽  
Neuronal Activity ◽  
Environmental Conditions ◽  
Muscle Activity ◽  
Muscle Cells ◽  
Major Effect ◽  
Whole Body ◽  
Effect Of Temperature ◽  
Whole Body Imaging

AbstractThe neural code relates the activity of the nervous system to the activity of the muscles to the generation of behavior. To decipher it, it would be ideal to comprehensively measure the activity of the entire nervous system and musculature in a behaving animal. As a step in this direction, we used the cnidarian Hydra vulgaris to explore how physiological and environmental conditions alter the activity of the entire neural and muscle tissue and affect behavior. We used whole-body calcium imaging of neurons and muscle cells and studied the effect of temperature, media osmolarity, nutritional state and body size on body contractions.In mounted Hydra, changes in temperature, nutrition or body size did not have a major effect on neural or muscle activity, or on behavior. But changes in media osmolarity altered body contractions, increasing them in hipo-osmolar media solutions and decreasing them in hyperosmolar media. Similar effects were seen in ectodermal, but not in endodermal muscle. Osmolarity also bidirectionally changed the activity of contraction bursts neurons, but not of rhythmic potential neurons.These findings show osmolarity-dependent changes in neuronal activity, muscle activity, and contractions, consistent with the hypothesis that contraction burst neurons respond to media osmolarity, activating ectodermal muscle to generate contraction bursts. This dedicated circuit could serve as an excretory system to prevent osmotic injury. This work demonstrates the feasibility of studying the entire neuronal and muscle activity of behaving animals.Significance StatementWe imaged whole-body muscle and neuronal activity in Hydra in response to different physiological and environmental conditions. Osmolarity bidirectionally altered Hydra contractile behavior. These changes were accompanied by corresponding changes in the activity of one neuronal circuit and one set of muscles. This work is a step toward comprehensive deciphering of the mechanisms of animal behavior by measuring the activity of all neurons and muscle cells.

scholarly journals Effect of temperature and carpel size during pre-anthesis on potential grain weight in wheat

1999 ◽  
Vol 132 (4) ◽  
pp. 453-459 ◽  
Author(s):  
D. F. CALDERINI ◽  
L. G. ABELEDO ◽  
R. SAVIN ◽  
G. A. SLAFER
Keyword(s):  
Heat Treatment ◽  
Environmental Conditions ◽  
Buenos Aires ◽  
Grain Weight ◽  
Effect Of Temperature ◽  
Sowing Dates ◽  
Short Period ◽  
Background Temperature ◽  
Higher Temperature ◽  
Maximum Temperatures

The effect of environmental conditions immediately before anthesis on potential grain weight was investigated in wheat at the experimental field of the Faculty of Agronomy (University of Buenos Aires, Argentina) during 1995 and 1996. Plants of two cultivars of wheat were grown in two environments (two contrasting sowing dates) to provide different background temperature conditions. In these environments, transparent boxes were installed covering the spikes in order to increase spike temperature for a short period (c. 6 days) immediately before anthesis, i.e. between ear emergence and anthesis. In both environments, transparent boxes increased mean temperatures by at least 3·8 °C. These increases were almost entirely due to the changes in maximum temperatures because minimum temperatures were little affected. Final grain weight was significantly reduced by higher temperature during the ear emergence–anthesis period. It is possible that this reduction could be mediated by the effect of the heat treatment on carpel weight at anthesis because a curvilinear association between final grain weight and carpel weight at anthesis was found. This curvilinear association may also indicate a threshold carpel weight for maximizing grain weight.

scholarly journals Effect of Temperature-Humidity-Index on Milk Performances of Local Born Holstein Dairy Cows Under Saharan Climate

2021 ◽  
Vol 24 (2) ◽  
pp. 24-36
Author(s):  
Lazoumi Ouarfli ◽  
Abdelmadjid Chehma
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Environmental Conditions ◽  
Arid Regions ◽  
Effect Of Temperature ◽  
Significant Drop ◽  
Temperature Humidity Index ◽  
Lactation Length ◽  
Humidity Index ◽  
Milking Frequency

Abstract The objective is to study the effect of heat stress on milk yield (MY) relative to milking records (n=18178) of native Holsteins (n=187), in the region of Ghardaia, according to periods of HS, using the temperature-humidity index (THI). With THI >72 during 07 months in the study area, which significantly (P<0.001) decrease the MY (-15.5% corresponding to 21.73 kg). Also, calving periods led to a significant drop (P < 0.001) in overall MY (7030.35 kg) of the order of (-14.6%), and over the lactation length (353.43 d), which explains 41% of the variations in MY. In addition, the non-significant effect (P=0.212) of the lactation range on the increase in MY, moreover, the lactation length shows a non-significant (P = 0.108) decrease (-4.68%) during heat stress (HS). Furthermore, the significant effect (P <0.001) of the interaction (Milking frequency × THI) on MY, when THI variates from < 74 to > 84, with regression of (-16.82% and -08.82%) of the MF (2X and 3X), respectively. Again, the NH cow is less sensitive to hyperthermia, so THI explains only 2% of the variation in MY levels. Thus, NH in arid regions have the ability to acclimatize to Saharan environmental conditions.

scholarly journals Frictional Behavior of Plain Woven Fabrics Constructed from Polyester and Cotton Yarns in Different Environmental Conditions

2012 ◽  
Vol 7 (2) ◽  
pp. 155892501200700 ◽  
Author(s):  
Ali Arshi ◽  
AliAsghar Asgharian Jeddi ◽  
AliAsghar Katbab
Keyword(s):  
Relative Humidity ◽  
Environmental Conditions ◽  
Fiber Material ◽  
Cotton Fabrics ◽  
Woven Fabrics ◽  
Effect Of Temperature ◽  
Warp Yarn ◽  
Polyester Fabrics ◽  
Significant Difference ◽  
Cotton Yarns

Frictional characteristics of woven fabrics can determine smoothness and softness values of the fabric. Moreover different environmental conditions can leads to change the properties of the weaves. In this paper, we studied the effect of temperature and relative humidity variations on the frictional properties of cotton and polyester fabrics. Plain woven fabrics were produced with polyester warp yarn and two different weft yarns (cotton and polyester). Each fabric was examined in various temperatures and relative humilities; then the frictional forces measurement was carried out on the fabrics in warp over warp direction. The results show that there is a statistically significant difference between the frictional parameters. This difference relates to the type of fiber material (weft yarns), temperature, and relative humidity. In addition, the data reveal that cotton fabrics have more static and kinetic forces than polyester fabrics in all environmental conditions. Moreover, polyester fabrics exposed to a temperature of nearly 45°C and 100% RH, have the maximum smoothness. The highest roughness values for cotton fabrics were under conditions of 45°C and 20% RH.

Thermal Post-Buckling of Laminated Plates Comprising Functionally Graded Materials With Temperature-Dependent Properties

2004 ◽  
Vol 71 (6) ◽  
pp. 839-850 ◽  
Author(s):  
K. M. Liew ◽  
J. Yang ◽  
S. Kitipornchai
Keyword(s):  
Functionally Graded Materials ◽  
Differential Quadrature Method ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Laminated Plates ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Graded Materials ◽  
Post Buckling ◽  
Temperature Dependent Properties

This paper presents thermal buckling and post-buckling analyses for moderately thick laminated rectangular plates that contain functionally graded materials (FGMs) and subjected to a uniform temperature change. The theoretical formulation employs the first-order shear deformation theory and accounts for the effect of temperature-dependent thermoelastic properties of the constituent materials and initial geometric imperfection. The principle of minimum total potential energy, the differential quadrature method, and iterative algorithms are used to obtain critical buckling temperatures and the post-buckling temperature-deflection curves. The results are presented for both symmetrically and unsymmetrically laminated plates with ceramic/metal functionally graded layers, showing the effects of temperature-dependent properties, layup scheme, material composition, initial imperfection, geometric parameters, and boundary conditions on buckling temperature and thermal post-buckling behavior.

Sign in / Sign up

Export Citation Format

Share Document