Water in the Arab World

This volume is intended to serve as a water handbook. It represents the collective knowledge about water resources management acquired over recent years, both within the World Bank water team and with counterparts working in the Arab countries of North Africa and the Middle East (MNA). The chapters offer a cornucopia of ideas and themes. Some chapters are based on background papers prepared for the 2007 "MNA Development Report on Water." Others draw on sector work prepared at the request of client countries. Yet others summarize observations based on study tours or other learning events sponsored by the World Bank. Upon reviewing this lodestone of embedded knowledge, we realized that bringing together our observations and analyses could serve a useful purpose for public officials, other practitioners, academics, and students who are interested in learning more about the complexities of managing water resources management in one of the driest parts of the world

MAT-744: ASSESSMENT OF PERFORMANCE OF BIO SELF-HEALING MORTAR USING DIATOMACEOUS EARTH AND SILICA FUME

Cracking represents a major threat for the integrity and performance of structures. Self-healing concept was introduced to construction materials in order to enhance their performance and extend their service life with less repair. This study aims at assessing the performance of Portland cement mortar incorporating self-healing Bacillus Pseudofirmus bacteria using Diatomaceous earth (DE) to immobilize precursor and bacteria in mortar and lowering the pH level of mortar by using silica fume to provide a suitable growth environment for bacteria to generate limestone. The specimens were prepared at three different bacteria dosages and three DE dosages. Cracking of specimens was induced by load percent concept after 7 days and tests were performed at 14 and 28 days of curing. Micro analysis of the healed crack surface of the different specimens was performed and a parametric study was conducted to select the optimum dosage of bacteria, DE and mix design combination as well. The testing scheme for the mortar included sporulation tests over bacteria inside mortar specimens, compression test, chemical soundness test and ultrasonic pulse velocity. Results demonstrate that self-healing bacteria is promising technique in minimizing cracking. It is recommended to expand this work to cover more dosages of bacteria, different types of self-healing as well as concrete specimens

Factors affecting the occurrence of postpartum depression among puerperal women in Sohag city, Egypt

Aim: Postpartum Depression (PPD) is one of the most common complications of the postpartum period. In Egypt, previous studies have reported that the prevalence of PPD ranged from 20-50% depending on location in Lower and Upper Egypt. This study aimed to evaluate the co-factors affecting the occurrence of PPD amongst puerperal women in Sohag city, Egypt. Methods: The study was carried out at Sohag University Hospital from June 2015 to May 2016. All women within 6 weeks after birth who gave their consent were included. A pretested questionnaire including demographic, psychosocial, maternal and infant variables as well as the Edinburgh Postnatal Depression Scale (EPDS) was completed. A woman with an EPDS score ≥13 was considered to have PPD, while a score \u3c 12 ruled out PPD. Results: We recruited 658 women, among whom 47 had an EPDS score ≥13, giving a prevalence of 7.14% of PPD. Women who delivered female babies or those who had a medical illness in their babies were significantly more likely to suffer from PPD. Conclusion: The prevalence of PPD in our setting was 7.14% which reflected the lowest prevalence among regions in Egypt. This could be due to differences of regional culture, families’ ties or other co-factors and needs further verification

Open circuit fault diagnosis technique for inverter switches and gate drive malfunction

Open circuit faults (OCFs) in voltage source inverters (VSIs) can significantly affect their performance and reliability. In this paper, a novel fault diagnosis technique (FDT)is presented for the detection and classification of two types of OCFs in VSIs: gate drive malfunction (GDM) and open switch fault (OSF). the effect of these OCFs on the output current of the VSI is analysed, this shows that they can be identified and distinguished using the average and root mean square (RMS) ratio of the current parameters. The proposed FDT is simple to implement and can identify switch faults with quick response, without the need for additional equipment. In this work the authors adopted the ensemble bagged tree classification method to detect and classify the GDM and OSF, the results show the credibility of the proposed technique in identifying different open circuit faults

Assessment of the Effect of two Different Digital Fabrication Techniques on Marginal and Internal Fit of Interim Fixed Dental Prothesis

Aim: The aim of that study was to evaluate the marginal and internal fit of a 3-unit, and 6-unit interim fixed dental prosthesis manufactured through milling and 3D printing technologies. Materials and Methods: Forty-eight interim fixed dental prostheses (FDP) were equally divided into two groups according to the fabrication technique. In group (MT), specimens were fabricated through milling technology while in group (PT), specimens were obtained by 3D printing. Each group was subdivided equally according to the FDP span length into 3-unit FDP (SFDP), and 6-unit FDP (LFDP). Marginal and internal fit were measured through the superimposition of the digital master model data and data of the fitting surfaces of the milled and printed FDPs using the “best-fit” alignment feature of a 3D evaluation superimposition software. The Mann-Whitney U test was used to compare the two fabrication techniques as well as the two span lengths. The significance level was set at P \u3c 0.05. Results: Results showed that 3D printing showed statistically significantly higher overall marginal gap distance (MGD) than the milling technique for the (SFDP) subgroup while milling showed higher overall (MGD) values than 3D printing for the (LFDP) subgroup. For internal fit, 3D printing showed lower overall internal gap distance values than milling. Conclusions: Milling technology was able to produce restorations with better marginal fit compared to 3D printing only in 3-unit FDPs. However, the opposite was true when the internal fit of the restorations was considered where 3D printing surpassed the milling technique in both the short-span and long-span FDPs. Consequently, 3D printing could be the technique of preference for fabricating provisional restorations especially when it comes to complex long span FDPs