The double yield (DY) phenomenon observed in a wide variety of semi-crystalline polymers (SCP) adds difficulties the material characterization. In this paper, constitutive model, termed as explicit polymer (ESCP) is proposed to study DY well rate- and temperature-dependent thermomechanical response below glass transition temperature. underlying kinetics due morphological changes spherulite micr...

Abstract The Initial Upper Paleolithic (IUP) is a key chrono-cultural concept in our understanding of the cultural and population dynamics at transition from Middle to period. This paper presents technological chronological analyses lithic assemblages rockshelter site Tor Fawaz Jebel Qalkha area, southern Jordan, provide accurate dating detailed recognition IUP variability Levant. We present in...

Abstract Given their ubiquity in modern society, the development of biodegradable and renewably sourced plastics is essential for creation an environmentally sustainable society. One drawbacks currently available such as poly( l -lactic acid) (PLLA) polyhydroxyalkanoates (PHAs) that it difficult to simultaneously achieve mechanical flexibility certain crystallization behavior these materials, w...

• LDPE films with controlled crystalline morphology were successfully prepared by dip coating method. Accelerate weathering experiment performed to study the influence of spherulite dimension on aging process. An increase erosion process for presenting largest spherulites is observed. Crack initiation favored film dimension. Erosion and crack propagation found be independent measured carbonyl i...

In protein crystallography, spherulites are considered the result of a failed crystallization experiment. Understanding the formation of these structures may contribute to finding methods to prevent their formation. Here, we present an in situ study on lysozyme spherulites grown from sodium nitrate and sodium thiocyanate solutions, investigating their morphology and growth kinetics using optica...

The process of mineral formation following periods of growth interruption (growth bands) is described. Flat pearl implantation as well as a new trepanning method are used to observe the transitory phases of calcium carbonate which nucleate and grow during this process. An initial random nucleation of the aragonite polymorph is observed followed by a transition towards spherulitic growth. During...

Experiments reported herein document heterogeneous crystal nucleation on bubbles in supercooled lithium disilicate melt. Crystalline lithium disilicate (Li2Si2O5) nucleated and grew on small bubbles (;1 mm) with a one-to-one correspondence between the number of bubbles and crystals (ranging from ,102 to ;105 bubbles/mm3). Crystals grew on large bubbles (.100 mm) only in samples fused in N2, sug...

Caillé analysis of the small-angle X-ray line shape of the lamellar phase of 7:3 wt/wt cetyltrimethylammonium tosylate (CTAT)/sodium dodecylbenzene sulfonate (SDBS) bilayers shows that the bending elastic constant is kappa = (0.62 +/- 0.09)k(B)T. From this and previous results, the Gaussian curvature constant is kappa = (-0.9 +/- 0.2)k(B)T. For 13:7 wt/wt CTAT/SDBS bilayers, the measured bendin...