A novel durable hydrophobic surface coating of poly(lactic acid) fabric by pulsed plasma polymerization

Effective finishing on poly(lactic acid) (PLA) fibres could be difficult due to its low melting point. Traditional fluorocarbon application technology (pad, dry, and cure at high temperature) on poly(ethylene terephthalate) and PLA fibres fabrics was compared with a novel plasma polymerization technique which was performed on both fabrics. Liquid repellency properties of both mentioned fabrics, before and after washing were evaluated. Fabric mechanical properties were compared by measuring bursting strength and fabric hand. The results indicate that, in general, the plasma process imparted better fabric handle and overall repellency, particularly with regard to low temperature re-orientation. Furthermore, by adding a proper softener, the inter-fibre friction was reduced and better elastic recovery was achieved.     

Preparation and properties of multi-walled carbon nanotube/poly(organophosphazene) composites

Carbon nanotubes (CNTs) are promising materials because of their unique properties. However, the poor solubility in solvents limits the function of CNTs and hinders their applications in many fields. Surface modification of CNTs with polymers is an efficient method to solve this problem. Several polymers were tested for the preparation of CNT dispersions. In comparison with organic polymers, poly(organophosphazenes) are highly stable macromolecules with adjustable properties which depend on the side groups. This article is to describe the synthesis of thermally stable and soluble multi-walled CNT/poly(organophosphazene) composites. The poly(organophosphazene)s substituted with (a) 100 % quaternary protonated pyridinoxy (PPY), (b) 50 % quaternary protonated pyridinoxy and 50 % a long aliphatic chain alcohol (1-dodecanol) (PDK), and (c) 50 % quaternary protonated pyridinoxy and 50 % a glycol ether [(2-(2-methoxyethoxy)ethanol] (PET) have been synthesized. f-MWCNT/poly(organophosphazene) composites have been prepared by the treatment of the functionalized multi-walled carbon nanotubes (f-MWCNT) with the protonated polyphosphazenes (PPY, PDK, and PET) using different feed ratios [R _feed = 1:1, 1:3, 1:5, 1:10 (w:w)]. The thermal stability of prepared composites (f-MWCNT/PPY, f-MWCNT/PDK, and f-MWCNT/PET) have been investigated by TGA. By considering thermal stabilities and solubility of all prepared composites, f-MWCNT/PPY_1:5, f-MWCNT/PDK_1:5, and f-MWCNT/PET_1:5 have been chosen as optimum composite composition and characterized by ³¹P NMR, ¹H NMR, XRD, Raman spectroscopy, and EDX analysis. The morphologic characterizations of the f-MWCNT/PPY_1:5, f-MWCNT/PDK_1:5, f-MWCNT/PET_1:5 nanocomposites have been carried out by HRTEM. Excellent dispersions of the nanocomposites in water and common organic solvents have been achieved. The solubility and thermal stability of nanocomposites depend on the side groups on poly(organophosphazene).     

Overview of Poly(lactic acid) (PLA) Fibre

Poly(lactic acid) (PLA), the first melt-processable synthetic fibre produced from annually renewable resources, combines ecological advantages with excellent performance in textiles. PLA successfully bridges the gap between synthetic and natural fibres and finds a wide range of uses, from medical and pharmaceutical applications to environmentally benign film and fibres for packaging, houseware, and clothing. Ease of melt processing, unique property spectrum, renewable source origin, and ease of composting and recycling at the end of its useful life has led to PLA fibres finding growing interest and acceptance over a range of commercial textile sectors. Our review of poly(lactic acid) (PLA) fibre is divided into two parts. Part I of this review gives information about production, properties, performance, environmental impact, and enduse applications of PLA fibres. The aim of Part II is to review the wet processing (pretreatment, dyeing, clearing, subsequent finishing treatments, washing, etc.) of PLA fibre and its effects on the fibre. These were accomplished through a broad literature survey, including recent research and development in the area.     

On the dual nature of intra-urban borders: The case of a Romani neighborhood in Istanbul

This essay questions the nature of intra-urban borders from a politico-ethical point of view. Namely: to what extent are intra-urban borders acceptable at a time of proliferating discourses about a borderless world, and open cities? We discuss this through a case study of Sulukule – a historic neighborhood home to a millennium old Roma community located within the historic city center of Istanbul – in the context of the urban renewal project launched by the local municipality. The often cited “humanitarian” pretext for the renewal project is “incorporating” the Sulukule’s poor Roma community into the city and tearing down the borders demarcating their ghetto. Eventually, this discourse of incorporation served to instigate a rapid episode of gentrification in the area. Offering a critical perspective on the municipality’s renewal project, and through a discussion of the often conflicting premises of the discourses of the “right to the city” and the “group right to difference,” this essay argues that intra-urban borders are “undecided” separators and calls for policy tools that are responsive to the enabling aspects of bordering processes.     

Delay-sensitive and multimedia communication in cognitive radio sensor networks

Multimedia and delay-sensitive data applications in cognitive radio sensor networks (CRSN) require efficient real-time communication and dynamic spectrum access (DSA) capabilities. This requirement poses emerging problems to be addressed in inherently resource-constrained sensor networks, and needs investigation of CRSN challenges with real-time communication requirements. In this paper, the main design challenges and principles for multimedia and delay-sensitive data transport in CRSN are introduced. The existing transport protocols and algorithms devised for cognitive radio ad hoc networks and wireless sensor networks (WSN) are explored from the perspective of CRSN paradigm. Specifically, the challenges for real-time transport in CRSN are investigated in different spectrum environments of smart grid, e.g., 500 kV substation, main power room and underground network transformer vaults. Open research issues for the realization of energy-efficient and real-time transport in CRSN are also presented. Overall, the performance evaluations provide valuable insights about real-time transport in CRSN and guide design decisions and trade-offs for CRSN applications in smart electric power grid.     

Seismic fragilities for non-ductile reinforced concrete frames – Role of aleatoric and epistemic uncertainties

Seismic fragilities are essential to earthquake loss estimation and performance-based earthquake engineering in regions of high seismicity. Construction practices for frames in regions of moderate seismicity are quite different, and such frames have received less attention in the literature. Fragilities for performance levels identified in recent seismic regulations are developed herein for reinforced concrete frames designed for gravity load in low-seismic regions using probabilistic non-linear finite element analysis. An examination of the contribution of uncertainties in material and structural parameters reveals that structural damping, concrete strength, and cracking strain in beam–column joints have the greatest impact on the fragilities of such frames. However, fragilities that incorporate these sources of uncertainty are only slightly different from those based solely on the uncertainty in seismic demand from earthquake ground motion, suggesting that fragilities that are developed under the assumption that all structural parameters are deterministic and equal to their median (or mean) values are sufficient for purposes of earthquake damage and loss estimation in regions of moderate seismicity. Confidence bounds on the fragilities are also presented as a measure of their accuracy for risk-informed decision-making, for prioritizing risk mitigation efforts in regions of low-to-moderate seismicity.     

Comparison of lactic acid contents between dried and frozen tarhana

The lactic acid content of tarhana produced with different dough treatments was determined. Trials were performed to see the effects of different parameters on organic acid produced during fermentation. In these trials, fermentation time, yogurt content and preservation method parameters were varied. Increasing fermentation time had a significant effect on lactic acid formation as well as total organic acid content of tarhana (p < 0.01). In the samples of tarhana with 50% yogurt, total acidity increased 29.9% in the first 48 h of fermentation. During the subsequent 48 h the increase was only 3.6%. Lactic acid increased 17.7% during the first 48 h followed by an increase of 3.1% during the next 48 h of fermentation in these same samples. On the other hand, when yogurt content was increased from 50% to 75%, total acidity in the first 48 h was 17.0% greater than the samples with 50% yogurt. There was also a 20.2% increase in lactic acid as well.     

A process model of Rho GTP-binding proteins

Rho GTP-binding proteins play a key role as molecular switches in many cellular activities. In response to extracellular stimuli and with the help of regulators (GEF, GAP, Effector, GDI), these proteins serve as switches that interact with their environment in a complex manner. Based on the structure of a published ordinary differential equations (ODE) model, we first present a generic process model for the Rho GTP-binding proteins, and compare it with the ODE model. We then extend the basic model to include the behaviour of the GDI regulators and explore the parameter space for the extended model with respect to biological data from the literature. We discuss the challenges this extension brings and the directions of further research. In particular, we present techniques for modular representation and refinement of process models, where, for example, different Rho proteins with different rates for regulator interactions can be given as instances of the same parametric model.     

The effects of wheat sourdough on glutenin patterns, dough rheology and bread properties

Sourdough was prepared with cellular suspension containing 10⁹ cfu of each strain mL⁻¹ and incubated at 28 °C for 24 h and at 37 °C for 4 h. Two different sourdough levels (20 and 40%) were used in bread dough preparation. The bread doughs were proofed at 30 °C and 85% relative humidity for 60/120/180 min. When glutenin changes that occurred in samples 17, 18, 19, and 20 (40% SD 28) are compared with those that appeared in controls, it is obvious that, the relative intensities of some of the protein bands slightly decreased and a few fainter protein bands appeared (which did not exist in controls). A few fainter protein bands corresponding to the MM ≈ 25 kDa (high-mobility region) and the MM ≈ 66 kDa (low-mobility region) were appeared in the same samples. In the samples prepared with 20% sourdoughs incubated at 28 or 37 °C, the bands were still evident after 180 min of proof. This can be explained that glutenin fractions were not hydrolysed in these applications due to the delay in pH drop. The use of 40% sourdough incubated at 28 °C for 24 h resulted in sticky doughs and breads with lower volume, harder texture, unsatisfactory crumb grain and unpleasant flavour than the rest of the samples. The use of sourdoughs incubated at 37 °C for 4 h caused positive effect on loaf volumes, specific loaf volumes and crumb structure.