Mechanical and Microstructural Properties of HDPE Pipes Manufactured via Orbital Friction Stir Welding.

In recent decades, extensive research has been performed on the friction stir welding of flat-shaped materials while pipe welding, particularly polymer pipes, still encounters challenging issues. This work presents a feasible route for joining high-density polyethylene (HDPE) pipes using an orbital friction stir welding (OFSW) set-up properly designed with a retractable pin tool. Fully consolidated joints were achieved using a portable heating-assisted OFSW system suited for on-site pipeline welding. The obtained joined pipes were characterized by a high-quality weld surface and a lack of defects arising from the tool-pin hole. The samples welded with the optimum parameters presented comparable properties with the base materials and even a slight increase in the tensile strength. The highest tensile and impact strengths were 14.4 MPa and 2.45 kJ/m2, respectively, which is 105% and 89% of those of the base material. XRD, FTIR, and SEM were also applied to assess the property changes in the HDPE pipes after the FSW process. The morphological analysis evidenced that the crystalline structure of the welded sample was similar to that of the base material, proving the effectiveness of the proposed technology.

The effect of foot reflexology massage on burn-specific pain anxiety and sleep quality and quantity of patients hospitalized in the burn intensive care unit (ICU).

BACKGROUND: Burn-specific pain anxiety and sleep disorders are common factors in burned patients that affect wound healing process, as well as the severity of burn pain. This study aimed to investigate the effect of foot reflexology massage on burn-specific pain anxiety and sleep condition of patients hospitalized in the burn ICU. METHOD: In this randomized controlled clinical trial, 52 patients were assigned by permuted block randomization 1:1 to the intervention (n=26) and control (n=26) groups. The intervention group received 20min of foot reflexology massage during 3 days on their third, fourth and fifth days of hospitalization and 15min before changing wound dressings. Patients in the control group merely received routine care. The Burn-Specific Pain Anxiety Scale (BSPAS) was completed for three consecutive days before and after changing wound dressings, and St. Mary's Hospital Sleep Questionnaire (SMHSQ) was filled out for four consecutive days before changing wound dressings for patients in both groups. The data were analyzed by IBM SPSS 16 software, Chicago, independent t, Chi-square, Friedman, Mann-Whitney and Wilcoxon tests. FINDINGS: We found no significant difference between pain-anxiety in the two groups before the intervention. The trend of different days in each groups were compared with Friedman test and showed that pain anxiety (p<0.001), sleep latency (p<0.001), duration of the last day's sleep (p<0.001) and satisfaction of the last night sleep (p<0.001) had a significant difference. In addition, Mann-Whitney test results showed that there were significant differences between the two groups at different times in terms of the above variables (p<0.05). The effect size was=0.82 for pain anxiety between group after the intervention. CONCLUSION: Based on the results, foot reflexology massage can effectively reduce pain anxiety levels and improve sleep quality and quantity of patients with burn injuries; therefore, this non- pharmacological therapeutic method is recommended to be used in the burn ICUs. (Clinical trial's registration code: IRCT20110906007494N27).

Partially Oxidized Cellulose grafted with Polyethylene Glycol mono-Methyl Ether (m-PEG) as Electrolyte Material for Lithium Polymer Battery.

Herein, a novel cellulose derivative has been synthesized and investigated as a nature-derived solid polymer electrolyte for lithium batteries. Cellulose is oxidized in a two-step process to dicarboxylic acid cellulose to allow for grafting low molecular weight poly(ethylene glycol) monomethyl ether (550 g mol-1) via Fischer-Speier esterification at the thus obtained carboxyl groups. The chemical structure of the synthesized materials is confirmed by Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy as well as X-ray diffraction. Incorporating lithium bis(trifluoromethane-sulfonyl)imide (LiTFSI) as conducting salt and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) ionic liquid as plasticizer results in the realization of an amorphous and solvent-free solid polymer electrolyte. These electrolyte membranes are characterized by high thermal and electrochemical stability and ionic conductivities of about 1×10-5 S cm-1 at 20 °C and 2.5×10-4 S cm-1 at 80 °C, which enables very stable lithium stripping and plating for more than 800 h.

Static DNA Nanostructures For Cancer Theranostics: Recent Progress In Design And Applications.

Among the various nano/biomaterials used in cancer treatment, the beauty and benefits of DNA nanocomposites are outstanding. The specificity and programmability of the base pairing of DNA strands, together with their ability to conjugate with different types of functionalities have realized unsurpassed potential for the production of two- and three-dimensional nano-sized structures in any shape, size, surface chemistry and functionality. This review aims to provide an insight into the diversity of static DNA nanodevices, including DNA origami, DNA polyhedra, DNA origami arrays and bioreactors, DNA nanoswitch, DNA nanoflower, hydrogel and dendrimer as young but promising platforms for cancer theranostics. The utility and potential of the individual formats in biomedical science and especially in cancer therapy will be discussed.

Phase diagrams of microemulsions containing reducing agents and metal salts as bases for the synthesis of metallic nanoparticles.

We studied the phase diagrams of microemulsions with a view to using these systems for the synthesis of metallic Pt, Pb, and Bi nanoparticles as well as of intermetallic Pt/Pb and Pt/Bi nanoparticles. The microemulsions consisted of H(2)O/salt-n-decane-SDS-1-butanol. The salt was either one metal precursor (H(2)PtCl(6) x 6 H(2)O, Pb(NO(3))(2), or Bi(NO(3))(3) x 5 H(2)O), a mixture of two metal precursors (H(2)PtCl(6) x 6 H(2)O + Pb(NO(3))(2) or H(2)PtCl(6) x 6 H(2)O + Bi(NO(3))(3) x 5 H(2)O), or the reducing agent (NaBH(4)). In addition, other salts needed to be added in order to solubilize the metal precursors, to stabilize the reducing agent, and to adjust the ionic strength. Combining the microemulsion (mu e1) that contains the metal precursor(s) with the microemulsion (mu e2) that contains the reducing agent leads to metallic nanoparticles. To study systematically how the shape and size of the synthesized metallic nanoparticles depend on the size and shape of the respective microemulsion droplets, first of all one has to find those conditions under which mu e1 and mu e2 have the same structure. For that purpose we determined the water emulsification failure boundary (wefb) of each microemulsion as it is at the wefb where the water droplets are known to be spherical. We found that the ionic strength (I) of the aqueous phase as well as the hard acid and hard base properties of the ions are the key tuning parameters for the location of the wefb.