We present a comprehensive model to computationally study molecular structure development in the recycling extrusion process of low-density polyethylene (LDPE) and provide initial results versus reported experiments as guidance. Molecular weight distribution (MWD) branching (BD) are modeled by applying combination population balance modeling, method moments pseudo distributions. Special cares h...

Chemically recycled monomer feed streams from postconsumer plastic packaging waste are expected to contain impurities that act as catalyst poisons. This work investigates the impact of such on a commercial fourth-generation Ziegler–Natta system. A stream in two different procedures by adding representative poisons (pyridine and n-butanol) various quantities reactor setup is simulated. Measuring...

The present study focuses on the influence of molecular weight distribution (MWD) crack-growth kinetics fatigue-crack propagation in high-density polyethylene (HDPE) homopolymers. Compact-tension specimens HDPE homopolymer grades, with polydispersities ranging from 2 to 45 and weight-averaged molar mass 49 450 kg/mol, are tested cyclic loading at temperatures between 23 92 °C. Through a variati...

AIM Sleep-disturbed breathing (SDB) is common in pre-capillary pulmonary hypertension (PH) and impairs daytime performance. In lack of proven effective treatments, we tested whether nocturnal oxygen therapy (NOT) or acetazolamide improve exercise performance and quality of life in patients with pre-capillary PH and SDB. METHODS This was a randomized, placebo-controlled, double-blind, three pe...

BACKGROUND Flooding may affect aeroallergen sensitization. OBJECTIVE To evaluate aeroallergen sensitization in children with asthma and/or allergic rhinitis (AR) by skin prick test (SPT) before and after the great flood of 2011 in Bangkok, Thailand. METHODS The study was performed retrospectively in asthma and/or AR children (aged 0-18 years) in Siriraj Hospital, Bangkok, Thailand from 2009...

introduction recently, employment of rotary tillers has been expanded in gardens and small farms, especially in the northern of iran. however using the l-shaped blades in the conventional rotary tillers have some problems such as severe vibration problems, weeds stucking around the blades, forming the plow pan and lower performance due to the less powers of such small rototillers. therefore in ...

Prostacyclin analogs, such as epoprostenol, treprostinil, iloprost, and beraprost, have long been used for pulmonary arterial hypertension (PAH) treatment, yet their relative efficiency remains disputed. Eligible randomized controlled trials (RCTs) involving the 4 therapies mentioned above were retrieved from PubMed, Embase, and Cochrane (up to August 1, 2015). Odds ratios (ORs) were estimated ...

It is well-known that the second smallest eigenvalue 22 of the difference Laplacian matrix of a graph G is related to the expansion properties of G. A more detailed analysis of this relation is given. Upper and lower bounds on the diameter and the mean distance in G in terms of 22 are derived.