Mechanical properties of crepe paper and chickpaper Mechanické vlastnosti krepového a “chickpaper“ papierov
The paper deals with the evaluation of the mechanical properties of the crepe paper and chickpaper. The thickness of crepe paper was 300 m with the surface mass 150 g*m and chickpaper paper thickness was 100 m with the surface mass 40 g*m. Crepe paper and chickpaper are usually used for chicken breeding. Longitudinal and transversal tensile properties were studied. The tensile behavior was monitored on the motorized test stand ANDILOG STENTOR 1000 (Andilog Technologies, Vitrolles, France).There were measured the tensile properties as modulus of elasticity, maximal elongation, maximal tensile force, tensile strengths, tensile index and strain at break of the longitudinal and transversal samples by testing paper strips. Mean values of the maximal elongation b of longitudinal chickpaper samples were three times smaller than maximal elongation of transversal samples. Mean values of maximal tensile force Ft, tensile strength  b tensile indexand maximal strain at break T of longitudinal chickpaper samples were two times smaller than maximal quantities of transversal samples. Mean values of the tensile modulus of elasticity of longitudinal and transversal chickpaper samples were almost equal. Chickpaper mechanical properties in tension were different in the longitudinal and transversal direction of the original paper surface. Mean values of the maximal elongation b and maximal strain at break T of longitudinal crepe paper samples were sixty times smaller than maximal elongation and maximal strain at break of transversal samples. Mean values of maximal tensile force Ft, tensile strength andtensile index w of longitudinal crepe paper samples were fourth times smaller than maximal quantities of transversal samples. Mean values of the tensile modulus of elasticity of longitudinal samples of crepe paper were thirty eight times smaller than values of transversal samples.
The Moisture and Rate-Dependent Mechanical Properties of Paper: A Review
Paper is a complex structure of composite biological fibers.The behavior of paper is time-dependent with respect to load, moisturecontent, or temperature, whether these control parameters are fixed orvaried in combination. A key question is whether the time-dependentproperties are a consequence of the fiber micro-structure, theinterfiber bond, the fiber distribution in a sheet, or a combination ofthese. Hypotheses for the physical mechanisms responsible forstress-strain relations observed under constant, monotonic, and cyclicloading and, especially, for the role of moisture bonding in thetime-dependent behavior are compared. The moisture accelerated creepphenomenon, due to varying ambient relative humidity, is an importanttime-dependent behavior which creates practical problems such as thewall collapse of stacked cartons in warehouses with non-constanthumidity and control of the paper-making machine. For each type ofloading and ambient control variation, after a discussion of possiblephysical mechanisms inducing the observed response, the mathematicalmodels proposed in the literature are reviewed as tools for the designof both the paper-making process and applications.
Intentional poisoning cases of animals with anticholinesterase pesticide-carbofuran in Sri Lanka.
Carbofuran is a broad spectrum insecticide and nematicide which inhibits acetyl cholinesterase. Several intentional poisoning cases of animals and birds including crows, dogs, cow, and elephant, using carbofuran were reported in Sri Lanka. Qualitative analysis of carbofuran in biological specimens was carried out using T.L.C and GC-MS. The quantitative analysis was carried out by HPLC using Zorbax Eclips XDB-C18 (150 x 4.6 mm I.D x 5 microm particle size) column with acetonitrile: water 25:75 v/v mobile phase and UV detection at 210 nm. The liquid-liquid extraction with chloroform was reproducible and sensitive. The procedure was validated in terms of linearity (0.996<r<0.999) for concentrations ranging from 1 to 200 microg/ml, repeatability (RSD 4.4% at 100 microg/ml, n=10) extraction recovery (91.7% at 100 microg/g, 77.3% at 20 microg/g), limit of detection (S/N ratio=3, 0.7 microg/ml) and limit of quantification (S/N ratio=10, 2.4 microg/ml). The method was found satisfactory and successfully applied in fatal cases of animals and birds due to carbofuran poisoning. The fatal carbofuran levels detected were in the range of 42-910 microg/g in crow's gizzard and contents, 50-800 microg/g in dog's stomach contents, 13-20 microg/g in dog's liver, 0.9 microg/g in cow's stomach and contents, 35 microg/g in elephant's stomach and contents.