Polyphenylene sulfide (PPS) superfine fiber is a promising high efficient material for high temperature dedusting. In this paper, the PPS superfine fiber was prepared by melt-electrospinning for the first time. In order to produce the finer fibers, the polypropylene (PP) was added to PPS and the effects of blending ratio, spinning voltage, spinning temperature, and spinning distance on resultant fibers were investigated systematically. The superfine fibers of PPS with an average diameter of 4.12 μm were successfully prepared at the optimized condition, which was one third of that by melt-spinning method. With the decrease of 76.21 % fibers diameter, the filter efficiency increased from 87.03 % to 98.05 %. The presented method provides a new way for the scalable and green fabrication of PPS superfine fibers.

Melt electrospinning is a technique capable of producing micro-and nanofibers with the advantages of being eco-friendly, cost-effective, and applied in many areas such as nonwovens with high performance, biomedicine, high-efficiency filtration, oil sorption, and many others. This chapter describes the current trends on melt electrospinning including advancements in the technique, processing parameters, materials, apparatus, and areas of applications. Melt differential electrospinning which is a new technique for nanofiber production invented by our innovation team of advanced polymer processing has been introduced. Future perspectives on melt electrospinning are also proposed.

With regard to oil production in Libya, the following instruments are particularly important:

- Sustainability guidelines

- Risk analyses

- Eco-efficiency analyses

- Balanced scorecards -

Key sustainability criteria (KPI)

- Certification systems

Sustainability consists of the balance between economic efficiency/economics on the one hand and ecology/environmental compatibility on the other. 15 Sustainable energy systems are always geared to demand. Energy is just one resource among many.

Employees, raw materials, knowledge, etc. are also important resources that need to be managed sustainably and a balance found. A system that is only one-sidedly focused on profit maximization or social compatibility

Abstract

This article presents yet another methodology for the calculation of dimensionless thermal response factors for vertical borehole ground heat exchanger (GHX) arrays, which is a concept introduced by Eskilson (1987). The presented method is based on a well-known solution to an analogous problem in the field of well hydraulics. This solution method, known mathematically as an incomplete Bessel function, and known in the field of well hydraulics as the 'leaky aquifer function', describes the hydraulic head distribution in an aquifer with predominantly radial flow to a well combined with vertical 'leakage' from geologic layers above and below the pumped aquifer. The solution is adapted to model heat transfer from an array of arbitrarily-placed vertical boreholes of finite depth. With proper expression of parameters in the incomplete Bessel function, we show that g-functions of previous researchers can be approximated. The proposed method has been implemented into Matlab and Excel/VBA for g-function generation and monthly GHX simulation.

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 …

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.

Abstract

In many cities today, owning a car has become an important and

dominant mode of transport. Increasing dominance of own cars as a mode

of transport is due to its inherent advantages associated with its usage. In

Tripoli, Libya due to rapid increase in car usage associated with poor public

transport system has resulted in an increase of traffic congestion, accidents

and lack of parking spaces. This study aims to identify the factors

preventing owning cars from shifting to public transport system (PT). And

to develop model shift from owning cars to public transport in order to

formulate policies to achieve this. A policy to enhance public transport

system usage and control car ownership simultaneously has become

necessary for solving traffic congestion problems. A questionnaire survey

was carried out on users of transport in Tripoli such as own car, taxis,

microbuses and coaches drivers (n = 900). The probability of car drivers

shifting to public transport was examined based on scenario of several

options such as reduction in public transport travel time and travel cost.

Reduction in total travel time and cost for public transport mode emerged as

the most important elements in attracting car users towards using public

transport system. Logistic regression technique has been used to analyze the

factors that impact users to switch their trips to public transportation

alternatives. Statistical Package for Social Science (SPSS) version 19 and

Excel 2007 software were used to analyze the questionnaire in this study

Key words: public transport, car ownership, logistic regression, mode

choice and traffic congestion.

ABSTRACT

Many Arab countries are starting to suffer from traffic congestion in their capitals cities, as

a consequence of continued increase in car ownership, current public transport vehicles

namely taxi, coaches and microbuses users and also lack of car parks. Tripoli, the capital

city of Libya where most of commuters prefer to use private cars,which is 88% of the city

traffic volume for doing work, study and shopping trips and one of these Arabic cities.

Government statistical data on the city for 2009 revealed that out of the total 945,203

vehicles comprised of 743,796 private cars and 47,031 units of taxis, coaches and

microbuses.In this study, traffic volume characteristics on three Tripoli's main entrances

namely, the eastern entrance covers Tajora (Al-Bive), the western entrance covers the AlGiran entrance and the southern entrance covers the Al-Gabis, Airport Road and Al-Hadaba

(Salah Al-Din) entrances were evaluated.The increase number of private cars and public

transport vehicles in the last ten years has resulted in traffic congestion. Field survey and

questionnaire study were carried out in Tripoli area in summer 2015 to explore the potential

reduction of private cars usage on road through optimal use of suitable public transportation

system. Statistical Package for Social Science (SPSS) version 19, Excel software and

logistic regression method were used to analyse these questionnaires. As a result, Tripoli

roads network users need to change and encourage usage of public transportation system as

public buses and rapid buses into the city.

Key words: Private car, public transport, parking places, entrances, traffic congestion