Effect Of Storage Age Research Articles

Effect of storage age and containers on the physicochemical degradation of guggul oleo-resin

Guggul is a gum oleo-resin, tapped from a data deficient plant- Commiphora wightii (Arnott.) Bhandari in India. It is extensively used in ayurvedic drugs and formulations since ages. Natural plant-based products; especially aromatic ones like guggul gum oleo-resin deteriorates, qualitatively during its storage and transits before reaching the industry for its value addition. This economical and ecological loss can be avoided if it is stored in proper containers. Physico-chemical degradation of guggul samples stored were analysed by scanned electron microscopy, fourier transformed infra red, thermogravimatric, Powdered X-ray diffraction and elemental analysis for carbon, hydrogen, nitrogen and sulphur. Physico-chemical degradation of guggul oleo-resin occurs with the age of storage and the type of storage containers used. Among the four storage containers (earthen pot, plastic jar, polythene bag, jute bag) evaluated, earthen pot was found to be the best in checking the qualitative loss of guggul even upto 24 months. The qualitative information generated in the study on guggul storage may be useful to the drug industry and guggul traders. It may encourage them practice storing guggul in earthen pots against current practice of using jute bags and polythene bags, to store it.

Massive transfusion protocol activation does not result in preferential use of older red blood cells.

Widespread, anecdotal belief exists that patients receiving massive transfusion, particularly those for whom a massive transfusion protocol (MTP) is activated, are more likely to receive older red blood cells (RBCs). Retrospective review of blood bank records from calendar year 2011 identified 131 patients emergently issued ≥10 RBC units (emergency release (ER)) prior to obtaining a type and screen. This cohort was subclassified based on whether there was MTP activation. For comparison, 176 identified patients transfused with ≥10 RBC units in a routine fashion over 24 hours represented the nonemergency release (nER) cohort. Though the median age of ER RBCs was 5 days older than nER RBCs (ER 20, nER 15 days, P < 0.001), both fell within the third week of storage. Regardless of MTP activation, transfused ER RBCs had the same median age (MTP 20, no-MTP 20 days, P = 0.069). In the ER cohort, transition to type-specific blood components increased the median age of transfused RBC units from 17 to 36 days (P < 0.001). These data refute the anecdotal belief that MTP activation results in transfusion of older RBCs. However, upon transition to type-specific blood components, the age of RBCs enters a range in which it is hypothesized that there may be a significant effect of storage age on clinical outcomes.

Damage Control Resuscitation with Fresh Blood Products Attenuates the Systemic Inflammatory Response Following Hemorrhagic Shock

Introduction: Hemorrhagic shock initiates a dysfunctional inflammatory response that clinically leads to increased morbidity and mortality. Damage control resuscitation used to treat severe hemorrhage routinely utilizes stored packed red blood cells (pRBCs) and plasma. Stored pRBCs undergo structural and functional changes over time, but the effect of storage age on inflammation following transfusion is unknown. We hypothesized that the transfusion of fresh blood products attenuates inflammation following hemorrhagic shock as compared to stored blood components.

Effects of Storage Aging on the Properties of Epoxy Prepregs

Changes in the properties of epoxy prepregs during storage are of both industrial and theoretical interest. It would be very helpful to have a test, suitable for production use, to determine when a prepreg has aged beyond acceptable limits. In this article, different epoxy prepregs aged under various conditions were studied by near-infrared (NIR) and mid-infrared (MIR) Fourier transform spectroscopies, dynamic mechanical analysis (DMA), rheological analysis, time-resolved light scattering (TRLS), and optical microscopy (OM). A very good relationship between storage aging time and curing conversion was obtained by NIR measurements. Furthermore, the rheological study showed that both the viscosity and the gelation time changed with storage aging. Changes in the glass transition temperatures of epoxy prepregs can result from either curing or phase separation during storage aging. The TRLS and OM results showed that structural evolution might occur during storage for some prepregs.

Effects of storage aging on the cure kinetics of T700/BMI prepregs for advanced composites

AbstractThe effects of room temperature aging on the cure kinetics of a bismaleimide (BMI) matrix prepreg have been characterized by different time and storage conditions. The study has focused on the stability of BMI matrix carbon fiber prepregs, when exposed to controlled environmental conditions before being used in composite manufacturing. The effects of aging on reactivity, glass transition temperature, and process window have been investigated by differential scanning calorimetrer through dynamic and isothermal tests. A theoretical kinetic model for epoxy matrix prepregs, developed in previous studies, has been applied to the cure of both aged and virgin BMI matrix. The model is able to satisfactorily describe the effect of processing variables such as temperature and degree of cure during the curing of the composite under different conditions (curing temperature and heating rate). The effects of diffusion‐controlled phenomena on the cure kinetics, associated with changes in glass transition temperature as a function of the degree of cure, have been taken into account in the formulation of an nth‐order kinetic model. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

Effects of concentrated HCl on the mechanical properties of storage aged fiber glass polyester composite

In this study the 15-years storage aged E-glass-fiber-reinforced polyester specimens were used. Effects of storage aging and acid immersion on tensile and flexural strength, modulus of elasticity and elongation at break at various times and temperatures were investigated. The storage aging caused 48, 10, 16 and 10.5% reduction in tensile and flexural strength, modulus of elasticity and elongation at break of the samples respectively. The storage aged samples immersed in HCl acid showed even more decrease in the mechanical properties. SEM micrographs of the samples (after and before immersion) showed failure mode at the interphase and the strength reduction due to degradation of fiber/matrix interfacial bond.

Effects of storage aging on the cure kinetics of bismaleimide prepregs

AbstractThe effects of room temperature aging on the subsequent polymerization kinetics of a bismaleimide (BMI) matrix prepreg, for high performance composites, have been characterized by different time and storage conditions. The study has focused on the stability of BMI matrix carbon fiber prepregs, when exposed to controlled environmental conditions before being used in composite manufacturing. The effects of aging on glass transition temperature, reactivity, and processability have been investigated by calorimetry through dynamic, isothermal, and cure‐simulating tests. A theoretical kinetic model for epoxy matrix prepregs, developed in previous studies, has been applied to the polymerization of both aged and unaged BMI matrix. The model is able to satisfactorily describe the effect of processing variables such as temperature and degree of reaction during the curing of the composite under different conditions (curing temperature and heating rate). The effects of diffusion‐controlled phenomena on the reaction kinetics, associated with changes in glass transition temperature as a function of the degree of polymerization and cross‐linking, have been taken into account in the formulation of an nth‐order kinetic model. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24: 253–265, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20048