Abstract-A series of polyelectrolyte hydrogels ranging from 92-98wt% were synthesized by copolymerization of acrylamide,

AAM with 2-acrylamido-2-methyl propane sulphonic acid, AMPS using 0.001g APS as initiator in the presence of 30wt% H2O

and 1.0wt% ethylene glycol dimethacrylate,EDMA as cross-linking agent. The final copolymers was obtained in the form of

glassy and transparent roads at room temperature, these roads were soaked in water for two days to remove unreacted

monomers. The swelling behavior of the hydrogels was studied in distilled water and salt solutions of 1.5 mol/l each of NaCl

and KCl. The Swelling in water shows decreasing values of q, LE, Ø1, EWC% and increasing polymer volume fraction, Ø2 by

increasing acrylamide, due to increasing hydrophobicity and decreasing the hydrophilicity. The swelling in salt solutions

shows a decreasing in the values of ESSNa%, WCNa%, SCNa%, ESSK%, WCK% and SCK% by increasing acrylamid

monomer in the feed due to increasing the hydrophobicity and decreasing the ionized ionic groups (SO3H). The increasing

values of ESSNa%, WCNa% and SCNa% compared with the values of ESSK%, WCK% and SCK% respectively, is due to

the higher charge density of sodium ion than that of potassium ion.

Six Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The

growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All

seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size.

Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and reduction

in root and shoot growth of the large-seeded species. The growth of seedlings of small-seeded species

was less impacted by cotyledon damage. The rate of survival, root and shoot lengths and dry biomass

of the seedlings were determined after 90 days. When seedlings were treated with balanced nutrient

solutions following removal of the cotyledons, survival was 95–98%, but 0% when supplied with

nutrient solutions lacking N or P or with water only. The addition of a balanced nutrient solution failed

to restore complete growth of any species, but the rate of root elongation for the small-seeded species

was maintained. Cotyledons provide nutrients to support early growth of Hakea seedlings, but other

physiological roles for the cotyledons are also implicated. In conclusion, small-seeded Hakea species can

tolerate cotyledons loss better than large-seeded species.

Marine Oil spills have become a serious environmental problem, and contribute to severe impacts and economic losses. Fast and efficient cleanup of oil from marine environment is vital. The use of sorbents is one of the most efficient techniques in removing oil from water. In this work, pure polypropylene (PP) ultrafine fibers with 2 μm diameter were prepared by air assisted melt electrospinning device to be used as oil sorbent. Two fiber samples were used in this study, fluffy, cotton like appearance and oriented, cloth like appearance with different porosities. The influence of temperature change on oil/water mixture was studied. Fluffy fibers showed a better performance in sorption capacity. Results indicated that change in temperature was an important factor in determining the sorption capacity of the fibers. Additionally, in contrast to solution electrospinning, melt electrospinning is safer, cost effective and …

The antifungal effect of thymoquinone, a component of black seed essential oil, has been studied on different types of fungi. Its mechanism of action as an antifungal has not been described yet. This study demonstrates the fungicidal effect of thymoquinone on different Candida species with particular emphasis on C. glabrata planktonic cells and biofilms. Since cell death was induced via the generation of oxidative stress as evidenced by the abrogation of thymoquinone toxicity in cells incubated with antioxidants, a part of thymoquinone’s mechanism of action includes a direct involvement as a pro-oxidant. This was further confirmed by measuring the generation of reactive oxygen species, glutathione level reduction and decrease in mitochondrial membrane potential. The oxidative stress caused by thymoquinone was confirmed to be the cause of death and not a result of cell death.

Abstract

Walking considered as one of the safest modes of

travel available, sustainable to human society as well as

environmentally beneficial. In this context, the aim of this

research is to investigate pedestrians’ traffic gap acceptance

and crossing decision for Mid-block Street crossing in urban

areas in Malaysia. Pedestrian crossing behaviour at

Rughaya Street has been examined in terms of the decision

to cross or not the street and size of traffic gaps accepted by

pedestrian, as well as the related contributing factors. A

field study was conducted to collect the data of pedestrians’

decisions under real mix traffic Condition using video

camera on a typical unsignalized urban street section. JPEG

files were obtained from video recording by using Snapshot

Wizard software. The data extracted included traffic

characteristics such as traffic size, traffic speed, etc.

pedestrian individual characteristics such as gender, in

addition to individual behavior such as waiting, frequency

of attempt, etc.). Furthermore, The extracted data were

used to develop and examine a pedestrian gap acceptance

model based on A lognormal regression model and binary

logistic model by SPSS (22) in order to validate the impact

of various parameters on the size of traffic gaps accepted by

pedestrians as well as the effect on the decision of

pedestrians to cross the street or not. So that the effect of

the gap accepted available and of other factors on the

decision of pedestrians to cross the street or not is examined.

These results indicate that the data set for this particular

location has a majority of male pedestrians which were

insignificant variables in both models moreover a lognormal

regression results shows that accepted gaps size depend on

traffic size, crossing distance, speed of approaching vehicle

and time spent by pedestrian at the curb waiting for a

suitable gap size to start crossing. The BL model performs

well for the reason that it captures the pedestrian decision

making process with traffic taking the relevant attributes

into consideration. According to the coefficients of BL

regression analysis equation we noticed that the illegal

parking, traffic size, traffic waiting time and gap size are the

vital attributes for the Pedestrian gap acceptance model..

Index Terms: Pedestrian crossing, gap acceptance, crossing

decision, multiple linear regression, binary logistic

regression.