Temporal variability of precipitation isotopes in Damascus, Syria — implications for regional climate change

Kattan Zuhair,Nasser Saeid 한국대기환경학회 2023 Asian Journal of Atmospheric Environment (AJAE) Vol.17 No.1

Records of stable isotopes (2H and 18O), deuterium excess (d-excess) and tritium (3H) values in precipitation (P) during 1990–2022, together with long-term time series (1919–2022) of air temperature (T) and P-amount values at the Damascus station, were analysed to explore the seasonal and annual variability patterns of those parameters in P and assess the vulnerability to climate change in this area. Variation of the annual average air T values over the period 1919–1969 shows an increase gradient of ≈ + 0.1 °C/decade. However, a remarkable much higher gradient (+ 0.64 °C/decade) is calculated for the period 1990–2022. The average P-amount value calculated for the last three decades (≈185 mm) was lower by ≈28 mm, compared to the value (≈213 mm), relative to the reference period (1919–1969). This significant decline in the annual P-amount value by ≈11–13%, accompanied by an annual heating of 0.2–0.6 °C/decade in the annual air T, is likely the result of the climate change affecting this area. The linear relationships between annual average δ18O and annual average δ2H values versus time over the period 1990–2019 indicate increased gradients in both stable isotopes (≈0.3–0.5‰ and ≈1.1–3.2‰ per decade for δ18O and δ2H, respectively), accompanied with a decrease gradient of ≈0.9–1.1‰ per decade in d-excess values. Variability of annual 3H concentrations towards low levels (< 6 TU) during the later years strongly suggests the return back towards the cosmogenic production of this radioisotope in the upper atmosphere. Information gained from this work would offer new insights to improve the understanding of the temporal variability of P isotopes and assess the risks associated with climate change on the natural water resources in the Eastern Mediterranean region.

Mesotheliomas in Lebanon: Witnessing a Change in Epidemiology

Kattan, Joseph,Eid, Roland,Kourie, Hampig Raphael,Farhat, Fadi,Ghosn, Marwan,Ghorra, Claude,Tomb, Roland Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.8

Background: Mesotheliomas are relatively rare tumors in Lebanon. The only previous study goes back to 14 years ago, when we published epidemiological characteristics of mesotheliomas in Lebanon, showing that the pleural location accounted for the vast majority of cases, with clear evidence of asbestos exposure from the Eternit factory of Chekka region. The objective of this current study was to estimate the incidence of mesothelioma in the past decade and to identify its epidemiological, clinical and therapeutic characteristics, making comparisons with our first study published in 2001. Materials and Methods: Between 2002 and 2014, patients diagnosed with malignant mesothelioma at Hotel-Dieu de France University Hospital were investigated. Epidemiological data focusing on asbestos exposure history were collected from medical records and interviews with the families. Results: A total of 26 patients were diagnosed with mesothelioma, 21 of which were successfully investigated. The mean age of these 21 patients is 62.5 (19-82). Only 3 (14.29%) are women. 18 (85.71%) were smokers. Among the 21 available mesotheliomas, 15 (71.4%) are pleural, while 5 (23.8%) are peritoneal and 1 (4.8%) pericardial. Only 60% of patients with pleural mesothelioma and 50% of those with an obvious exposure to asbestos lived and/or worked in Chekka region. The mean time of asbestos exposure in patients with mesothelioma is 24.5 (1-50) years and the mean latency is 37.4 (4-61) years. Of the 21 patients, 10 (47.6%) underwent surgery during their treatment, 16 (76.2%) received chemotherapy and 3 (14.3%) received best supportive care. Conclusions: Compared to the previous study (1991-2000), substantial changes in the epidemiology of mesothelioma in Lebanon were observed, such as an increase in peritoneal localizations and a lower correlation with Chekka region asbestos contamination.

Spatial Mapping of Atmospheric Precipitation Isotopes in Syria

Zuhair Kattan 한국대기환경학회 2021 Asian Journal of Atmospheric Environment (AJAE) Vol.15 No.2

Stable isotope ratios (δ2H and δ18O), tritium (3H). and deuterium excess (d-excess) values of atmospheric precipitation (P) at 16 stations were determined for mapping the spatial variation of oxygen and hydrogen P isotopes in Syria. The major geographical parameters (longitude east, LE; latitude north, LN; altitude, H; and inland distance from the coast, DFC) were used to find out the best fitting models for the spatial mapping of atmospheric P isotopes in Syria. The highest correlation coefficients (r>0.73) were found for the relationships δ18O-H and δ2H-H. The impacts of LE and LN factors were rather moderate (0.3<r<0.6). However, a high correlation coefficient (r>0.7) was found for the relationship d-excess-LN. The increase of d-excess value from 23‰ to 24‰ in southern Syria is due to the Mediterranean Sea (MS) moisture, likely as a high percentage (>65%) of prevailed winds usually comes over the MS. The concentrations of 3H in P samples (4-14 TU) during the period 1989-1993 were higher than those (3-10 TU) for the period 2004-2006, indicating thus a return back toward the levels of typical 3H production in nature. The high correlation coefficients (r>0.59) that were found for the relationships 3H-DFC and 3H-LE, suggest a continuous exchange between the low tritium moisture from the MS and the higher tritium moisture from the inland areas. Produced gridded isotopic values are quite satisfactory for covering certain areas in Syria and the neighboring Arab countries.

Bus rapid transit – a review

S.C.Wirasinghe,L. Kattan,M.M. Rahman,J. Hubbell,R. Thilakaratne,S. Anowar 서울시립대학교 도시과학연구원 2013 도시과학국제저널 Vol.17 No.1

Bus Rapid Transit (BRT) has been demonstrated to provide efficient and effective public transport that can even increase transit ridership and attractiveness within defined urban corridors in both developing and developed countries. The merit of the BRT system lies in its ability to provide a high quality public transit service with limited infrastructure and at a relatively low capital and operating cost. In this paper an attempt is made to review BRT characteristics in some detail. An overview of the elements of BRT systems: the running ways, vehicles, stations, as well as operational control, fare collection and passenger information systems is presented. This paper also discusses how these elements allows BRT services to achieve the speed, capacity, reliability, accessibility and operational safety characteristics that distinguishes such systems from regular express bus services. Each built BRT system is unique and depends on how these basic elements are designed and integrated. Environmental, social and economic impacts, users’ perception and modal shift towards BRT have also been critically reviewed. With the presence of local land use and transport policies that support high-density and mixed developments, BRT has been found to attract potential developments around stations and along its corridor, increasing land values and promoting sustainable development. As reported in the literature, the infrastructure costs vary greatly depending on the costs of land acquisition, station design, degree of separation from traffic, technological features and material, labor costs. Thus, BRT capital costs cannot be generalised and must be transferred carefully based on the changes of the input costs that vary from one place to another. The barriers to BRT that block the achievement of significant success in customer satisfaction and ridership gains are mentioned with specific case studies. The review of BRT indicates that in some cases it has similar performance to higher order public transit; however, it still has its unique characteristics that set it apart.

Optimization of demand-responsive transit systems using zonal strategy

Lin Wang,Wirasinghe,Lina Kattan,Saeid Saidi 서울시립대학교 도시과학연구원 2018 도시과학국제저널 Vol.22 No.3

A mathematical model was developed and applied to optimize many to one demand-responsive transit (DRT) systems using a zonal strategy. Such a DRT system provides service between a residential area and a terminal. The model is used to design the transit system, with its terminal sitting within the service area, by minimizing costs that are separately generated in service zones. The decision variables are area of service zone and bus headway. Also stepwise procedures are derived to geographically and sequentially divide the service area into a number of service zones with optimal areas. A case study is conducted for a presumptive demand-responsive transit system operating in northwest Calgary, showing that the model can successfully assist in designing demand-responsive transit systems.

A New Class of Damage Variables in Continuum Damage Mechanics

Voyiadjis, G.Z.,Kattan, P.I. AMERICAN SOCIETY MECHANICAL ENGINEERS 2012 Journal of engineering materials and technology Vol.134 No.2

Study of Discharge in Point-Plane Air Interval Using Fuzzy Logic

Bourek, Yacine,Mokhnache, Leila,Nait Said, Nacereddine,Kattan, Rafik The Korean Institute of Electrical Engineers 2009 Journal of Electrical Engineering & Technology Vol.4 No.3

The objective of this paper is to study the discharge phenomenon for a point-plane air interval using an original fuzzy logic system. Firstly, a physical model based on streamer theory with consideration of the space charge fields due to electrons and positive ions is proposed. To test this model we have calculated the breakdown threshold voltage for a point-plane air interval. The same model is used to determine the discharge steps for different configurations as an inference data base. Secondly, using results obtained by the numerical simulation of the previous model, we have introduced the fuzzy logic technique to predict the breakdown threshold voltage of the same configurations used in the numerical model and make estimation on the insulating state of the air interval. From the comparison of obtained results, we can conclude that they are in accordance with the experimental ones obtained for breakdown discharges in different point-plane air gaps collected from the literature. The proposed study using fuzzy logic technique shows a good performance in the analysis of different discharge steps of the air interval.

New Tensors for Anisotropic Damage in Continuum Damage Mechanics

Voyiadjis, G.Z.,Yousef, M.A.,Kattan, P.I. AMERICAN SOCIETY MECHANICAL ENGINEERS 2012 Journal of engineering materials and technology Vol.134 No.2

Public Transportation and Sustainability: A Review

Patrick Miller,Alexandre G. de Barros,Lina Kattan,S.C.Wirasinghe 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.3

Public transportation is often framed as a key component of building sustainable cities. Conversely, the social, economic, and environmental impacts of transport are framed as critical issues that can challenge the sustainability of cities and regions. This paper presents a critical literature review of the relationship between public transportation and sustainability. First the paper offers a review of key sustainable transportation concepts and how public transport contributes to sustainability goals. Second, the paper reviews past studies that analyse sustainable transportation in order to develop recommendations for planning, engineering, and researching sustainable public transport. Finally, the paper concludes by offering suggestions for future research into the sustainability performance of public transit.

Modelling traveller response to variable message sign

Joydip Majumder,Khandkar Nurul Habib,Lina Kattan,Tak Shing Fung 서울시립대학교 도시과학연구원 2013 도시과학국제저널 Vol.17 No.2

Rapid traffic growth in Calgary has put increased pressure in city's roadway network, especially on Deerfoot Trail which provides a fast access to north–south potion of the city. The city disseminates traffic information in Deerfoot through variable message sign (VMS) in case of major delays and usually diverts traffic to alternate parallel arterials. However, the reroute tendency of travellers significantly affects the diversion pattern at the VMS locations and this research targets the frequent users of Deerfoot Trail and investigates their rerouting tendency in light of important trip attributes drivers might associate with their trips. A total of 471 responses are collected from frequent users of Deerfoot Trail through a questionnaire survey and the analysis is focused on developing a relationship between reroute tendency and a set of explanatory variables, using generalized ordered logit (GOLOGIT) model and partially generalized regression models. The results have led to the conclusion that in addition to various socio-economic attributes, network familiarity and information access characteristics; trip characteristics also possess significant influences in rerouting decision-making. The study also proposes several implications for better design and operation of advanced traveller information systems and future effort on model estimation in light of the finding of the study.