Measurement of interfacial tension in hydrocarbon/water/dispersant systems at deepwater conditions

The events of the Deepwater Horizon oil spill in the Gulf of Mexico were associated with great water depths that made it difficult to understand the behavior of the spilled oil as it came in contact with the seawater. The remedial subsea application of chemical dispersants draws interest to evaluate the interfacial interactions between the oil and water at such great water depths. Most importantly, a quantification of the interfacial tension (IFT) between the spilled oil and seawater at deepwater conditions can provide insight into the effectiveness of the chemical dispersion of spilled oil. In this study, Macondo crude oil and synthetic seawater samples were used to measure the oil/water IFT by the Pendant Drop method at deepwater conditions of pressure and temperature. A laboratory apparatus capable of representing such conditions was designed and established to enable IFT and density measurements. Reagent grade n-octane was also used to compare its behavior to that of crude oil. The effectiveness of a commercial dispersant, Corexit® 9500, was assessed through the evaluation of the magnitude of the reduction in the hydrocarbon/water IFT. The influence of pressure, temperature, water salinity and dispersant concentration on the IFT was each studied independently as well. The measured oil/water IFT decreased from 25.69 to 22.55 mN/m as both pressure and temperature were changed from water surface to seafloor conditions. The dispersant was capable of reducing the IFT by 70 % from its original value at the water surface while only a 50 % reduction was observed at seafloor conditions. The low temperature associated with the seafloor was determined as the main factor responsible for deteriorating the dispersant effectiveness as pressure had a relatively smaller effect on the IFT. The dispersant was also observed to perform better when dissolved in the crude oil as compared to the time it was dissolved in the water. However, at 10,000 ppm dispersant-in-oil concentration, the oil adopted the shape of a continuous stream instead of breaking up into small droplets. Accordingly, ultra-low oil/water IFT was not achieved, despite such a high dispersant concentration, indicating ineffective chemical dispersion at seafloor conditions

Avoiding instabilities in short gap car-followings with connected autonomous vehicles

The image of driverless vehicles cruising on highways has been coming closer to reality over the last years thanks to the constant investigations in the technologies used in Connected and Automated Vehicles (CAV). Platooning of CAVs has been the focal point of investigations due to the potential benefits that can be reaped from the proper implementation of platoons on highways. One of the challenges facing the successful operation of platoons is the bullwhip phenomenon that causes propagating perturbations in platoons hindering its stability. The present study focuses on eliminating or reducing the bullwhip effect suffered by vehicles in a platoon. The aforementioned platoon algorithm will be governed by the formula of the Desired Space Gap (DSG) as followers will have to maintain a gap equal to the DSG to follow the leader. This algorithm managed to successfully carry out any increase or decrease in velocity of the platoon however, in the case of braking it has proved to be extremely unstable and suffers from effect of the bullwhip phenomenon. The average cumulative gap was used as a solution to trigger an instant response from all vehicles down the platoon to the actions of the leader as it was observed that vehicles in the end of the platoon tend to approach the leaders at high velocities because they only start decreasing their velocities once the vehicle ahead of them decelerates rather than the leader. This solution has been effective in significantly reducing the bullwhip effect on some vehicles in the platoon only, mainly the ones at the end of the platoon. Furthermore, this solution has given positive results only in cases of great changes in velocity

Memory-full context-aware predictive mobility management in dual connectivity 5G networks

Network densification with small cell deployment is being considered as one of the dominant themes in the fifth generation (5G) cellular system. Despite the capacity gains, such deployment scenarios raise several challenges from mobility management perspective. The small cell size, which implies a small cell residence time, will increase the handover (HO) rate dramatically. Consequently, the HO latency will become a critical consideration in the 5G era. The latter requires an intelligent, fast and light-weight HO procedure with minimal signalling overhead. In this direction, we propose a memory-full context-aware HO scheme with mobility prediction to achieve the aforementioned objectives. We consider a dual connectivity radio access network architecture with logical separation between control and data planes because it offers relaxed constraints in implementing the predictive approaches. The proposed scheme predicts future HO events along with the expected HO time by combining radio frequency performance to physical proximity along with the user context in terms of speed, direction and HO history. To minimise the processing and the storage requirements whilst improving the prediction performance, a user-specific prediction triggering threshold is proposed. The prediction outcome is utilised to perform advance HO signalling whilst suspending the periodic transmission of measurement reports. Analytical and simulation results show that the proposed scheme provides promising gains over the conventional approach

Optimal Management of community Demand Response

More than one-third of the electricity produced globally is consumed by the residential sectors [1], with nearly 17% of CO2 emissions, are coming from residential buildings according to reports from 2018 [2] [3]. In order to cope with increase in electricity demand and consumption, while considering the environmental impacts, electricity providers are seeking to implement solutions to help them balance the supply with the electricity demand while mitigating emissions. Thus, increasing the number of conventional generation units and using unreliable renewable source of energy is not a viable investment. That’s why, in recent years research attention has shifted to demand side solutions [4]. This research investigates the optimal management for an urban residential community, that can help in reducing energy consumption and peak and CO2 emissions. This will help to put an agreement with the grid operator for an agreed load shape, for efficient demand response (DR) program implementation. This work uses a framework known as CityLearn [2]. It is based on a Machine Learning branch known as Reinforcement Learning (RL), and it is used to test a variety of intelligent agents for optimizing building load consumption and load shape. The RL agent is used for controlling hot water and chilled water storages, as well as the battery system. When compared to the regular building usage, the results demonstrate that utilizing an RL agent for storage system control can be helpful, as the electricity consumption is greatly reduced when it’s compared to the normal building consumption

Association of Intraleukocytic Malaria Pigment with Disease Severity, Diagnosis and Prognosis in Sudanese Patients

Abstract: malaria is one of the most frequent hemoparasitic infections in tropical and sub-tropical countries. Malaria in Sudan is the major public health problem. This study was aimed to investigate the association of intraleukocytic pigment with malaria infection (severity, diagnosis and prognosis), and to investigate the correlation of parasite density levels with Malaria Severity. A total of 176 participants was drawn from the population of sudanese patient above 5 years, who attended or were admitted to the Bashayer Hospital, with diagnosis suggestive of malaria, they were selected for inclusion in the study. Blood films were examined first for malaria parasites diagnosis ,this was followed by detection of malaria pigment in both negative and positive films.Then Immunochromatography test was done, Subsequently haemoglobin concentration was determined. This study was approves that malaria pigment in peripheral blood leukocytes is evident for malaria disease , and makes the method of pigment determination appropriate and useful in malaria diagnosis, especially in patients with an illness consistent clinically with malaria but with negative blood smear due to haemolytic anaemia .A total of 176, 73 male and 103 female aged from 7 years to 69 years , drawn to Bashayer hospital with symptoms of malaria showed ICT positive result .Blood films were positive in 98(55.7%) and negative in 78 (44.3%) of patients . Malaria pigment was observed with the mean (22.07). There was an association between ICT and malaria pigment (P-value = 0.000).There was no association between BF and malaria pigment ( P-value = 0.40).This study also approved that malaria pigment can be used in prognosis, were thirty five patient showed complications(19.9%) and 141 showed no complication(80.1%) ,there was association between complications and malaria pigment ( P-value = 0.004) .This study also validates the presence of malaria pigment in leukocyte as a marker for disease severity, there was association between severity and malaria pigment (P-value = 0.02). While there is no association between density and severity (P-value = 0.980). So we conclued, intraleukocytic malaria pigment produced by parasites during intra erythrocytic development is associated with severe disease, mortality and it is a useful diagnostic indicator in anaemic patients with negative blood smears. The varied complexities of the current diagnostic methods make the method of pigment determination appropriate and useful. Secondly, malaria pigment is significantly associated with severe malaria. Thirdly, parasitaemia levels are neither associated nor correlated with malaria severity and therefore parasitaemia alone is not a reliable measure of malaria severity. We recommend the use of malaria pigment as marker for malaria disease severity. We recommend that parasitaemia should not be used alone as an indicator of malaria severity. We further recommend that, the presence of pigment in leukocytes to be adopted for diagnosis of malaria especially in cases of negative blood films, and recommend using malaria pigment as indicator for malaria prognosis

Soba Upper- Draught Hoff-Mann Kiln Temperature Distribution

This study aimed to convert the operation of Soba circular kiln, the top-fired one, with the suction of hot gases up-wards (upper- draught kiln), to the way of suction of heat down-wards (down-draught kiln) in order to draw and distribute the high concentrated quantity of heat at the kiln top-crown down- wards to the bottom of the kiln, and allover of it as much as possible. Suction-pipes of special specifications was used to link between the bottom of the kiln and the main exhaust suction-pipes system in order to draw the hot gases concentrated at the kiln top-crown, down-wards to the bottom of the kiln. Extensive field work and laboratory studies had been carried out during this study achieved a consistent results and finding lead to a good high quantity and quality of fired red bricks

Development of the first dual inhibitors for steroid sulfatase (STS) and 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) : a novel treatment approach for endometriosis

Endometriosis is an estrogen dependent disease (EDD) that has no satisfying treatment option, as the existing ones mainly comprise endocrine treatments that lead to severe systemic hypo-estrogenic side effects. Steroid sulfatase (STS) and 17β hydroxysteroid dehydrogenase type 1 (17β HSD1) are attractive new targets for the treatment of EDDs. Their inhibition leads to blockage of the local biosynthesis of estrogen without significantly affecting the circulating estrogen. The simultaneous inhibition of both enzymes appears to be more promising than the blockage of only one protein. The main aim of this study is the development of dual inhibitors of STS and 17β-HSD1 (DSHIs) that offers a novel treatment option for endometriosis without severe side effects. Using a designed multiple ligand (DML) approach, the first DSHIs were identified. Upon structural optimizations, highly potent inhibitors in cell-free and cellular assays were achieved that are characterized by high selectivity over 17β-HSD2 which plays a protective role in endometriosis. The DSHIs were able to efficiently reverse the E1-S and E1- induced T47D cell proliferation. The most interesting inhibitor described in this work is characterized by high metabolic stability in human and mouse hepatic S9 fraction, along with good physicochemical properties and high safety margins in cytotoxicity assays. Furthermore, this DSHI is considered a suitable candidate for in vivo proof of principle studies based on its pharmacokinetic profile.Endometriose ist eine Estrogen-abhängige Erkrankung für die bislang keine zufriedenstellende Therapieoption existiert. Zum Einsatz kommen hauptsächlich endokrine Behandlungen, die systemisch zu stark hypoestrogenen Zuständen und damit zusammenhängenden, ernsthaften Nebenwirkungen führen. Die Enzyme Steroid Sulfatase (STS) and 17β-Hydroxysteroid Dehydrogenase Typ 1 (17β-HSD1) sind attraktive, neuartige Targets zur Behandlung Estrogen-abhängiger Erkrankung. Ihre Inhibierung führt zur Hemmung lokaler Estrogen-Biosynthese, ohne starke Beeinflussung systemischer Estrogen-Konzentrationen. Die gleichzeitige Hemmung beider Enzyme erscheint vielversprechender als die Blockade eines einzelnen Proteins. Ein Gegenstand der vorliegenden Arbeit ist die Entwicklung dualer Inhibitoren von STS und 17β-HSD1 (DSHIs). Solche Wirkstoffe sind eine neuartige Therapieoption für Endometriose, die nicht zu den erwähnten Nebenwirkungen führt. Unter Anwendung eines Ansatzes zum gezielten Design von Liganden mehrerer biologischer Targets wurden die ersten DSHIs identifiziert. Anschließende Strukturoptimierungen führten zu Wirkstoffen, die in Zell-freien und zellbasierten Assays beide Targetenzyme hochpotent hemmten. Darüberhinaus waren die DSHIs in der Lage, die Estronsulfat- und Estron-induzierte Proliferation von T47D Zellen vollständig aufzuheben. Die vielversprechendste Verbindung zeigt hohe metabolische Stabilität in den S9-Lebermikrosomenfraktionen von Mensch und Maus, vorteilhafte physiko-chemische Eigenschaften und geringe Cytotoxizität. Darüberhinaus zeigte sie günstige pharmakokinetische Eigenschaften in der Maus, was sie zu einem geeigneten Kandidaten für eine proof-of-principle Studie macht

Control-data separation architecture for cellular radio access networks: a survey and outlook

Conventional cellular systems are designed to ensure ubiquitous coverage with an always present wireless channel irrespective of the spatial and temporal demand of service. This approach raises several problems due to the tight coupling between network and data access points, as well as the paradigm shift towards data-oriented services, heterogeneous deployments and network densification. A logical separation between control and data planes is seen as a promising solution that could overcome these issues, by providing data services under the umbrella of a coverage layer. This article presents a holistic survey of existing literature on the control-data separation architecture (CDSA) for cellular radio access networks. As a starting point, we discuss the fundamentals, concepts, and general structure of the CDSA. Then, we point out limitations of the conventional architecture in futuristic deployment scenarios. In addition, we present and critically discuss the work that has been done to investigate potential benefits of the CDSA, as well as its technical challenges and enabling technologies. Finally, an overview of standardisation proposals related to this research vision is provided

Predictive and core-network efficient RRC signalling for active state handover in RANs with control/data separation

Frequent handovers (HOs) in dense small cell deployment scenarios could lead to a dramatic increase in signalling overhead. This suggests a paradigm shift towards a signalling conscious cellular architecture with intelligent mobility management. In this direction, a futuristic radio access network with a logical separation between control and data planes has been proposed in research community. It aims to overcome limitations of the conventional architecture by providing high data rate services under the umbrella of a coverage layer in a dual connection mode. This approach enables signalling efficient HO procedures, since the control plane remains unchanged when the users move within the footprint of the same umbrella. Considering this configuration, we propose a core-network efficient radio resource control (RRC) signalling scheme for active state HO and develop an analytical framework to evaluate its signalling load as a function of network density, user mobility and session characteristics. In addition, we propose an intelligent HO prediction scheme with advance resource preparation in order to minimise the HO signalling latency. Numerical and simulation results show promising gains in terms of reduction in HO latency and signalling load as compared with conventional approaches

Gunshot Injuries: Patterns, Presentations, and Outcomes of Civilian Hospital Experiences in a Developing Country Setting

Background: Gunshot injuries are considered a health burden as well as one of the intricate emergencies in civilian medical practice. In this study, we aim to determine the pattern of presentation and management outcome in a general hospital setting in a sub-Saharan African country.Methods: This is a retrospective, hospital-based study conducted between January 2015 and December 2019 in a general teaching hospital to review the clinical presentation and management outcome of gunshot injuries. All patients’ records were reviewed during the study period.Results: The total number of patients involved in the study was 157 with 83% male predominant. About 50% were from the age group 20–29 years that were most affected. The commonest anatomical site affected in the study was the lower limb (41.4%) and upper limb (22.9%), and most of the patients had been diagnosed with limb fractures (49.7%) and soft tissue injuries (28.7%). Wound debridement is the commonest procedure performed for 91 (58.0%) patients. The site of the pullet has a significant relation to the management outcome with a P-value of 0.002. Additionally, about 45% (72 patients) have stayed more than 20 days and it was affected significantly by the types of treatment provided, which has a significant relation to a hospital stay with a P-value of 0.00.Conclusion: Most of the patients in this study were young males. Upper and lower limb fractures were the most common presentations. Wound debridement, bone fixation, and laparotomy were the most common treatments with significant success rates, despite prolonged hospital stays