Background and Problem Statement. Water Hammer Pressure Vessels project was initiated for the protection of bulk water supply pipelines against high water surges primarily caused by initial pump start-ups. The primary benefits of having a surge protected pipeline are increased reliability and prolonged useful life of the water pipes, thus ensuring continuity of bulk water supply to Rand Water customers. The surge protection achieves optimal functionality of the hydraulic protection system. The installed tanks require the stipulated 36 months’ statutory inspections in accordance with the Pressure Equipment Regulations that form part of the Occupation Health and Safety act and Regulations No. 85 of 1993 as amended. The first group of surge tanks; namely: A20-2, A14-3, A12-2, A6-1 and A8-1 were isolated on the 18th May 2017 for recertification. After testing the tanks, it was evident that several bladders were damaged, hence the need to procure 16 bladders for the recertification process are required.
Background and Problem Statement. Cervical cancer is the second highest cause of cancer mortality among women worldwide, largely due to the lack of population-based routine screening and treatment modalities in the developing world.1 Before the introduction of the Papanicolaou, or Pap, test in the 1950’s, cervical cancer was the foremost cause of cancer death among American women as there was no method for screening high grade precursors.2 Since the introduction of organized cervical cancer screening programs in the United States in the1950’s and 1960’s, the cancer mortality rate has dropped considerably. Cervical cancer is currently the 14th most common cause of cancer death for women in the United States.3 Each year, approximately 4,000 women in the United States die from cervical cancer.4 Deaths caused by cervical cancer are highly preventable, as the development of invasive cervical cancer from precancerous lesions is relatively slow. The growth period for precancerous lesions to develop into invasive cervical cancer can take up to 10 years.5 Hence, secondary prevention efforts focused on the detection and treatment of precancerous lesions, such as routine Pap test screening, have the potential to dramatically improve cervical cancer death rates. Pap test screening programs are estimated to have reduced cervical cancer deaths in the U.S. by up to 70% in some studies.6 Despite standardized national recommendations, the number of women receiving routine Pap tests in the United States is insufficient. As a component of its “Healthy People 2020” initiative, the U.S. Department of Health and Human Services set a goal of increasing to 93% the proportion of women aged 21 to 65 who received cervical cancer screening within the past three years.7 Data from the 2010 National Health Interview Survey (NHIS) highlighted the shortfalls in cervical cancer screening nationwide. Only 83% of women in the general population with no hysterectomy had received a Pap test within the past 3 years, considerably less than the “Healthy People 2020,” target of 93%.8 In an effort to close gaps in cervical and breast cancer screening rates among underserved women, the United States Congress created the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) in 1991. The NBCCEDP obligates federal funds to states for the provision of free cancer screening, diagnostic tests, and public education and outreach; in the case of cervical cancer, services provided through the program include Pap tests, colposc...
Background and Problem Statement. Saltwater intrusion into the coastal part of the surficial aquifer of southeast Florida is a major concern for water-supply managers in Broward County, Florida. The general west-to-east decrease in the height of the potentiometric surface causes flow of fresh groundwater eastward and towards the saline groundwater that intrudes along the coastline. The result is a dynamic mixing zone that forms the interface between the two fluids, which is often called the saltwater front. The location of the saltwater front and the width of this mixing zone is heavily influenced by the local hydrology and responds to changes to the hydrologic conditions. Increases in mean sea level would likely lead to decreased west-to-east groundwater level gradients resulting in a reduced seaward fresh-groundwater flux and westward intrusion of the saltwater front. Increases in coastal wellfield pumping or decreases in groundwater recharge (e.g., dry season, periods of drought) can also lead to saltwater intrusion. Conversely, decreases in coastal wellfield pumping and increases in groundwater recharge (e.g., wet season, wet years) can result in the seaward movement of the saltwater front. Saltwater intrusion into the coastal wellfields poses a threat to the fresh drinking water supplies in coastal areas. A variable density, numerical groundwater model capable of simulating the three-dimensional distribution of salinity within the surficial aquifer could be used to simulate the encroachment of the saltwater front further into the county under various projections of future hydrologic conditions.
1). The "northern model" was calibrated using Parameter ESTimation (PEST) software (Xxxxxxx, 2010) and sea-level rise was simulated using four (4) different rates over a 100-year period. Xxxxxx and others (2016) used the techniques from these previous two (2) models to develop a saltwater-intrusion model for the central and southern parts of Broward County. The "central/southern model" was c.alibrated using PEST and simulated historical conditions from 1950 to 2012 (fig.
2). The model was used to evaluate the sensitivity of the salinity distribution to sea-level rise and change� to well-field pumping rates. Since the release of the northern and central/southern saltwater intrusion models, Broward County has worked to combine the model inputs into one (1) "merged model" encompassing all the urban areas within the county. The county has also worked to extend the historical simulation period and f...
Background and Problem Statement. Problem Statement An estimated 9 million children under five years of age died worldwide in 2007 with half of these deaths occurring in sub-Saharan Africa (WHO 2009, UNICEF 2009).
