Innovative Application of Scrap-tire Steel Cords in Concrete Mixes

More than 2.5 million scrap-tires are produced in Jordan each year. In addition, more than three million tires are currently stockpiled throughout the country. However, only one company has been established in the country for the recycling, recovery and reuse of scrap-tires. Currently, this industry is facing many challenges due to lack of support and subsidies from the government. Many researchers have investigated the use of recycled tire products in several traditional civil engineering materials. This research is exploring the use of steel cords, a by product of the tire recycling process, in concrete mixes. Different concrete specimens were fabricated and tested in uniaxial compression and splitting tensile strength. The steel cords were substituted into the concrete mix in volumetric percentages of 0% (control), 2%, 4%, 6%, 8% and 10%. Results show that mechanical properties of concrete made with steel cords are improved compared with concrete mix made with the traditional scrap-tires recycled material (such as crump rubber or rubber chips). Also, the test results show that even though the compressive strength is reduced when using steel cords, this reduction is minimal. When 2% of steel cords are used, there is an 18% increase in ductility. Moreover, splitting tensile tests show that concrete mixtures with any steel cords content have much greater toughness than the control mixture. This mechanical property mix indicates an excellent potential application of modified concrete mix in structures that absorb large amounts of energy. On the contrary, the density, air content and workability of the mixtures fabricated were not significantly affected

Assessing Mechanical Properties of Hot Mix Asphalt with Wire Wool Fibers

This paper investigates the potential application of wire wool in the modification of hot asphalt mixes (HMA). Wire wool material is widely available at local markets as a by-product of wire wool industry and as waste products from homes. For the purpose of this study, wire wool was cut into small pieces so that it can be placed in the asphalt mixes. Different percentages of wire wool were incorporated with the hot asphalt mixes (0.0%, 0.25%, and 0.5%) of the total weight of the asphalt binder. Various experimental tests were used to evaluate the modification effectiveness of combining wire wool with hot asphalt mixes, namely, the Marshall Stability, indirect tensile strength (ITS), dynamic creep, fatigue, and rutting tests. Test results proved that the addition of wire wool increased the tensile strength of the asphalt concrete mixes. However, rutting increased due to increasing percentage of wire wool. Therefore, mixes containing wire wool can be used in areas where rutting is not the expected predominant distress type

Topographic and Clinical Characteristics of a Sample of Jordanian Students

Purpose: To screen for keratoconus (KC) and potential associated risk factors in a sample of medical students. Methods: This cross sectional study included 120 medical students studying at The University of Jordan. They were randomly selected from a total of 400 students. Participants responded by completing a self-administered questionnaire. Following initial clinical evaluation, corneal tomography images and indices were analyzed by an experienced ophthalmologist, after which the participants were classified into: normal, KC suspects and KC patients. Results: A total of 120 participants (mean age, 23.1 ±0.5 years) were included in this study, 70 (58.3%) were females and 50 (41.7%) were males. Two subjects had KC, demonstrating a prevalence of 1.7% while five (4.2%) participants showed at least two abnormal indices and were considered as KC suspects.Conclusion: the result of this study is similar to other studies conducted in the Middle East, which indicates a higher prevalence of KC than other western countries. Combined with the significantly impaired vision-related quality of life and the relatively young onset of disease, the burden of keratoconus represents a significant public health concern

Simulation and optimisation of a medium scale reverse osmosis brackish water desalination system under variable feed quality: Energy saving and maintenance opportunity

YesIn this work, we considered model-based simulation and optimisation of a medium scale brackish water desalination process. The mathematical model is validated using actual multistage RO plant data of Al- Hashemite University (Jordan). Using the validated model, the sensitivity of different operating parameters such as pump pressure, brackish water flow rate and seasonal water temperature (covering the whole year) on the performance indicators such as productivity, product salinity and specific energy consumption of the process is conducted. For a given feed flow rate and pump pressure, winter season produces less freshwater that in summer in line with the assumption that winter water demand is less than that in summer. With the soaring energy prices globally, any opportunity for the reduction of energy is not only desirable from the economic point of view but is an absolute necessity to meet the net zero carbon emission pledge by many nations, as globally most desalination plants use fossil fuel as the main source of energy. Therefore, the second part of this paper attempts to minimise the specific energy consumption of the RO system using model-based optimisation technique. The study resulted not only 19 % reduction in specific energy but also 4.46 % increase in productivity in a particular season of the year. For fixed product demand, this opens the opportunity for scheduling cleaning and maintenance of the RO process without having to consider full system shutdown

Delayed intravitreal anti-vegf therapy for patients during the covid-19 lockdown: An ethical endeavor

Purpose: To assess the impact of Jordanian’s Corona Virus Disease (COVID-19) lockdown on visual acuity and macular thickness in patients with macular edema receiving intravitreal injections, and to assess the ethical endeavor of lockdown among serious sight threatening conditions. Patients and Methods: This retrospective observational study included patients planned for intravitreal injections who did not complete the planned course before the lockdown (ie, before 20th of March 2020). Data included demographics, indication for the intravitreal injection, corrected distance visual acuity (CDVA), and central macular thickness on Optical Coherence Tomography (OCT) before and after the lockdown. Results: One-hundred and sixty-six eyes of 125 patients were studied, 68 (54.4%) patients were males, and the mean (± standard deviation, SD) age was 64.79 (±9.41) years. Mean (±SD) duration of delay in the planned injection was 60.97 (±24.35) days. The change in visual acuity was statistically significant for patients with diabetic macular edema (p= 0.045 improvement), patients with central retinal vein thrombosis (CRVO) (p= 0.05 deterioration), and patients with age-related macular degeneration (AMD) (p= 0.005 deterioration). Of interest, delay of more than 2 months and the previous need for 3 or more injections were significant poor prognostic factors for visual outcome for patients with diabetic macular edema (p=0.027 and 0.045). Conclusion: The impact of delay in the scheduled intravitreal injections resulted in variable outcomes depending on the indication. Triaging the urgency of patients should be based on the indication to support the equity principle of bioethics, where those in need are prioritized against others, depending on potential adverse outcome

Outcome of Penetrating Keratoplasty (PKP) and Redo PKP among Jordanian Population

Background: The success of penetrating keratoplasty (PKP) is determined by the duration of graft survival, which is the time to graft failure. Our study aims to identify various indications of corneal graft among our Jordanian population, their success rate as well as spotting the light on cases of re-grafting. Methods: In this study, we analyzed data for patients who had PKP as well as re-do PKP in the period from January 2014 to June 2017. For each study eye, we identified pre-operative visual acuity as well as visual acuity at six months and one year. We also focused on the specific indication for PKP, the surgical procedure and graft clarity at one year post-op. On SPSS statistical analysis software, we used repeated measure ANOVA, Pearson correlations, and Fischer’s exact test to analyze our study’s variables.Results: We included a total of 230 patients in this study with a mean age of 34.22 (±19.32). They were 112 (48.7%) males and 118 (±51.3%) females. We found a significant difference in mean age and outcome (p< 0.001), as the mean age for patients with successful PKP was 31.55 (±16.55) compared to 44.1 (±25.1) for patients with failed PKP. the success rate for patients with KC as an indication was 96.7% compared to only 58.3% for other indications. We found that failure rate in redo surgeries was significantly higher than first time surgeries.Conclusion: Among the Jordanian population, we found that Keratoconus was the main indication for PKP in our population, where we also found that it was associated with the best prognosis

A System Dynamics Approach for Hospital Waste Management in a City in a Developing Country: The Case of Nablus, Palestine

Hospitals and health centers provide a variety of healthcare services and normally generate hazardous waste as well as general waste. General waste has a similar nature to that of municipal solid waste and therefore could be disposed of in municipal landfills. However, hazardous waste poses risks to public health, unless it is properly managed. The hospital waste management system encompasses many factors, i.e., number of beds, number of employees, level of service, population, birth rate, fertility rate, and not in my back yard (NIMBY) syndrome. Therefore, this management system requires a comprehensive analysis to determine the role of each factor and its influence on the whole system. In this research, a hospital waste management simulation model is presented based on the system dynamics technique to determine the interaction among these factors in the system using a software package, ithink. This model is used to estimate waste segregation as this is important in the hospital waste management system to minimize risk to public health. Real data has been obtained from a case study of the city of Nablus, Palestine to validate the model. The model exhibits wastes generated from three types of hospitals (private, charitable, and government) by considering the number of both inpatients and outpatients depending on the population of the city under study. The model also offers the facility to compare the total waste generated among these different types of hospitals and anticipate and predict the future generated waste both infectious and non-infectious and the treatment cost incurred

Prevalence and risk factors of hepatitis B and C viruses among haemodialysis patients in Gaza strip, Palestine

<p>Abstract</p> <p>Background</p> <p>The prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) and its associated risk factors among haemodialysis (HD) patients in Gaza strip was investigated using serological and molecular techniques.</p> <p>Results</p> <p>The overall prevalence of HBV among the four HD centers was 8.1%. The main risk factors were HD center (p = 0.05), history of blood transfusion (p < 0.01), and treatment abroad (p = 0.01). The overall prevalence of HCV among the four HD centers was 22%. The main risk factors were HD center (p < 0.01), time duration on HD (p < 0.01), history of blood transfusion (p < 0.01), treatment abroad (p < 0.01), and history of blood transfusion abroad (p < 0.01). Serum aminotransferases levels decreased in HD patients compared with normal population but still there was a direct association between the activity of liver enzymes and both HBV (p < 0.01) and HCV (p < 0.01) infection.</p> <p>Conclusion</p> <p>The much higher prevalence of Hepatitis viruses among HD patients compared to the normal population of Gaza strip indicates a causative relation between HD and hepatitis viruses transmission. Therefore extremely careful observation of preventive infection control measures is essential to limit Hepatitis viruses' transmission in HD centers.</p

Prevalence of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma in Upper Egypt

<p>Abstract</p> <p>Background</p> <p>Pseudoexfoliation (PXF) is a recognized risk factor for developing cataract, glaucoma and lens dislocation. PXF is also associated with increased risk of complications during cataract surgery due to poor mydriasis and zonular weakness. The aim of this study is to report the prevalence of pseudoexfoliation among Upper Egyptians attending the ophthalmology clinic of Assiut University Hospital.</p> <p>Methodology</p> <p>A retrospective, chart review study conducted in the period from February 2002 to August 2009. A total of 7738 patients aged 40 years or older attending the general ophthalmic clinics were included in this study. A detailed evaluation including ophthalmic and general history, slit lamp biomicroscopy, intraocular pressure measurement, gonioscopy and dilated eye examination were performed. Patients with pseudoexfoliative material on the anterior lens surface and ⁄ or the pupillary margin in either or both eyes were labeled as having PXF.</p> <p>Results</p> <p>Out of the 7738 patients included, three hundred twenty (4.14%) subjects had PXF. Mean age of PXF group was 68.15 years (SD 8.16, range 40-92 years). PXF was bilateral in 82.2% of cases. It was significantly associated with cataract, glaucoma and hearing loss. Of the PXF patients, 65% had cataract, 30.3% had glaucoma and 8.1% had hearing loss.</p> <p>Conclusion</p> <p>Pseudoexfoliation appears to be a common disorder in older individuals in Upper Egypt.</p