Polymer–metal complexes: Synthesis and characterization of poly(4-acetyl-3-hydroxyphenylacrylate) and its metal chelates

4-Acetyl-3-hydroxyphenylacrylate (AHAH) was synthesized and polymerized in 2-butanone using benzoyl peroxide as initiator. Poly(4-acetyl-3-hydroxyphenyl-acrylate) (PAHAH) was characterized by infrared and nuclear magnetic resonance techniques. The molecular weight of the polymer was determined by gel permeation chromatography. Cu(II) and Ni(II) chelates of PAHAH were synthesized. The diffuse reflectance spectra and magnetic moments of the polychelates show distorted planar and octahedral structures for poly[Ni(AHA)₂] and poly[Cu(AHA)₂(OH₂)₂] complexes, respectively. The thermal properties of the polychelates are also discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 177–182, 1998     

Synthesis,characterization and liquid crystalline properties of polyacrylates and polymethacrylates containing aryl ester pendant unit

Aryloxycarbonylphenyl acrylates and methacrylates were prepared by reacting 4‐acryloyloxybenzoyl chloride and 4‐methacryloyloxybenzoyl chloride with different phenols. They were homopolymerized using benzoyl peroxide as the initiator at 65°C in dimethylformamide. The polymers were characterized by IR and ¹H–NMR spectra and size exclusion chromatography. Differential scanning calorimetry and polarizing optical microscopy studies revealed that the phenyl esters of poly(4‐acryloyloxybenzoic acid) and poly(4‐methacryloyloxybenzoic acid) did not show any liquid crystalline properties, but, the para‐aryl–substituted phenyl esters did exhibit mesophase properties in the temperature range of 98–265°C depending on the nature of the aryl substituent. Polymethacrylates exhibit higher T_g, and lower T_m and T_i than the polyacrylates having the same pendant mesogen. Thermogravimetric analyses have shown that the initial decomposition temperatures of the polymers are above 230°C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 465–474, 2000     

Photosensitive polymers: Synthesis,characterization, and photocrosslinking properties of polymers with pendant α,β-unsaturated ketone moiety

Acrylate and methacrylate monomers with the photodimerizable α,β-unsaturated ketone moiety, such as 4-cinnamoylphenyl, 4-(4-methoxycinnamoyl)phenyl, 4-(4-nitrocinnamoyl)phenyl, or 4-(4-chlorocinnamoyl)phenyl, were prepared and homopolymerized using benzoyl peroxide as the initiator at 70°C in methyl ethyl ketone. The poly(meth)acrylates were characterized by ultraviolet, infrared, ¹H-nuclear magnetic resonance (NMR), and ¹³C-NMR spectra, and gel permeation chromatography. Their thermal properties were studied by thermogravimetric analyses in air and nitrogen, and differential scanning calorimetry. The photocrosslinking properties of the polymers were investigated as thin films and in solution in the presence and absence of sensitizer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2111–2120, 1998     

An efficient handover decision in heterogeneous LTE-A networks under the assistance of users’ profile

The increasing demand for wireless networks calls for the use of heterogeneous networks in order to fulfil user requirements. Mobility management is considered one of the important entities for such networks. The handover is one of the main features of mobility management in regard to the long term evolution advanced (LTE-A) system, which depends purely on the hard handover. The vertical handover decision is a significant component of heterogeneous networks; it authorizes the user equipment (UE) to migrate between the two-tier LTE-A wireless networks. Femtocell, or also known as the home-evolved nodeB (HeNB), has turned out to be a promising arrangement, as it enhances the coverage and the quality of service for users on one hand, and offloads the eNB on the other hand. In this paper, an advanced handover technique is presented, in terms of adding new and critical parameters, as well as combining between the present UE trajectory and the HeNB cell location. A polynomial function is used to predict the future UE position while the cosine function along with distance are used for the selection of an appropriate target cell. The proposed algorithm is evaluated and then compared to the present work based on the handover number, number of signaling measurements, packet delay ratio, packet loss ratio, and system throughput. Simulation of the LTE-Sim demonstrates that the proposed algorithm significantly reduces the number of handovers, the transmission measurement number, the packet delay ratio, and the packet loss ratio and increases system throughput.     

Risk Analysis and Assessment to Enhance Safety in a Smart Kitchen

Cooking activity is accompanied with several risks, mainly for elderly people due to attention and memory impairment. Literature reveals that the kitchen is the second most common place for domestic accidents. We argue that enhancing safety during cooking activities could be achieved via designing a cooking-safe environment based on insightful risk analysis and assessment study. This paper presents our study on risk analysis and assessment during cooking, in order to build a cooking-safe environment. The study is based on theoretical and real-world experimentations. Risk analysis and assessment enabled us to determine the three major risks (i.e., fire, burn and intoxication by gas/smoke) and the pertinent parameters to quantify these risks. The results reveal that the pertinent parameters are: concentrations of volatile organic compounds, alcohol, and carbon monoxide gases in the cooking smoke, utensil temperature, burner temperature, relative humidity, and presence of a utensil on burner. We present in details our study on risk analysis and assessment, including the methodology and the findings.     

Mixed alkanethiol monolayers on submicrometric gold patterns: a controlled platform for studying cell-ligand interactions

Nanoscale organization of surface ligands often has a critical effect on cell-surface interactions. We have developed an experimental system that allows a high degree of control over the 2-D spatial distribution of ligands. As a proof of concept, we used the developed system to study how T-cell activation is independently affected by antigen density and antigen amount per cell. Arrays of submicrometer gold islands at varying surface coverage were defined on silicon by electron beam lithography (EBL). The gold islands were functionalized with alkanethiol self-assembled monolayers (SAMs) containing a small antigen, 2,4,6-trinotrophenyl (TNP), at various densities. Genetically engineered T-cell hybridomas expressing TNP-specific chimeric T-cell antigen receptor (CAR) were cultured on the SAMs, and their activation was assessed by IL-2 secretion and CD69 expression. It was found that, at constant antigen density, activation increased monotonically with the amount of antigen, while at constant antigen amount activation was maximal at an intermediate antigen density, whose value was independent of the amount of antigen.     

Upgrading of crude oil via distillation processes

Distillation is a unit operation of separating the components from a liquid mixture by selective evaporation and condensation. To obtain a pure liquid by distillation of a mixture must be applied in this process, numerous consecutive. Multistage distillation usually preferred instead of a single stage distillation. Fractional distillation is an example of a multistage distillation. Industrial-scale productions in all multistage or multitray distillation are applied. The composition of crude varies with its origin or geographical location. The contents of crude oil can be separated into different fractions with a series of fractional distillation processes.     

Evaluation of the percutaneous absorption of chlorpromazine from PLO gels across porcine ear and human abdominal skin

Objective: The overall objective of this work is to determine the percutaneous absorption of chlorpromazine hydrochloride from pluronic lecithin organogels (PLO gels) and verify the suitability of topically applied chlorpromazine hydrochloride PLO gels for use in hospice patients for relieving symptoms such as vomiting and nausea during the end stages of life.

Methods: PLO gels of chlorpromazine hydrochloride were prepared using isopropyl palmitate (IPP) or ricinoleic acid (RA) as oil phase. In vitro percutaneous absorption of chlorpromazine hydrochloride was assessed through porcine ear and human abdominal skin. Further, the theoretical steady state plasma concentration (C_ss) of chlorpromazine was calculated from the flux values.

Results: The pH, viscosity, and stability of both PLO gels prepared with IPP and RA were comparable. The thixotropic property of RA PLO gel was found to be better than that of IPP PLO gel. The permeation of chlorpromazine hydrochloride was higher from RA PLO gel than from IPP PLO gel and pure drug solution. Theoretical C_ss of chlorpromazine from pure drug solution, IPP PLO gel and RA PLO gel were found to be 1.05, 1.20, and 1.50?ng/ml, respectively. PLO gels only marginally increased the flux and theoretical C_ss of chlorpromazine.

Conclusion: From this study, it is clearly evident that PLO gels fail to achieve required systemic levels of chlorpromazine following topical application. Chlorpromazine PLO gel may not be effective in treating nausea and vomiting for hospice patients with swallowing difficulties.