Methodology for Designing and Evaluating Chemical Systems for Improved Oil Recovery

The purpose of this research was to demonstrate the methodology for development of high performance chemical systems for improved oil recovery (IOR). Previous studies have shown that high performing surfactant formulations can be quickly identified and optimized by assessing the microemulsion phase behavior and aqueous phase homogeneity. Similarly, in this research, extensive phase behavior assessments were performed for many combinations of chemical slug components that included various surfactants, co-surfactants, co-solvents, alkali and polymers. Methodical planning, preparation, execution, observations and recording of phase behavior experiments and results enabled selection of the best performing chemical components and their concentrations were optimized. A total of five formulations showed good microemulsion phase behavior but only three passed the aqueous stability requirement. These three formulations were then evaluated in core floods. Out of the three formulations, one consistently gave high residual oil recovery ranging between 86%-91% at reservoir temperature with both soft brine (NaCl only) and synthetic formation brine. Synthetic formation brine for Trembley contained a high concentration of divalent cations in addition to monovalent yet it had a minimal effect on oil recovery, proving that the formulation was robust at even high salinity contrast with formation brine. The formulation was therefore recommended for further studies on limestone cores. Pressures across the sandstone cores and its subsections, and effluent's microemulsion and aqueous phase properties were utilized to explain the performance of formulations and oil displacement process in the sandstone cores. Corefloods showed that slug size, surfactant concentration, salinity and viscosity of chemical systems were important chemical flood design parameters that also impacted the oil recovery

Taliban’s takeover of Afghanistan and Pakistan’s security challenges

Despite friendly relations between the two countries, the Taliban’s takeover of Afghanistan has been far from an unmixed blessing for neighbouring Pakistan. Zahid Shahab Ahmed provides the context and assesses the security challenges that Pakistan faces arising out of the Taliban’s rule over Afghanistan

The Role of the Pakistani Mass Media in the Lawyers’ Resistance against the Musharraf Dictatorship, 2007-2009

In the present context, when the civil movements have shaken the Arab world with successes in Libya and Egypt, it is appropriate to look back at the triumphant lawyers’ movement against dictatorship in Pakistan. Pakistan has a long history of coup d'état by army generals who until now have ruled the country for more than three decades in three different rules. The lawyers’ struggle became a catalyst for one of the most memorable and incredible social movements in Pakistan’s history. There have been studies on various aspects of this movement, especially the lawyers’ leadership and organization, but not on the role of the mass media and its impact of this particular civil struggle. This paper analyses some aspects of the Pakistani mass media that contributed to sustaining the lawyers’ resistance against General Pervez Musharraf’s authoritarian rule. This paper focuses on the role of TV channels and internet in the civil resistance led by the lawyers during the period of 2007 and 2009

National Identity Formation in Pakistan: Analysis of the Anti-Secular Narrative

Soon after its declaration as an Islamic Republic in 1956, Islamists have experienced numerous ups and downs in Pakistan. Islamists not only try to maintain the status quo of the Islamic state but also endeavour to expand the scope of sharia. Despite insignificant achievements in elections, Islamists have mostly been able to dictate civilian and military governments in matters of national identity. One of the greatest challenges for the promotion of pluralism is the Islamists’ anti-secular narrative, which holds significant backing from both the civil and the military elites. The goal of this paper is to analyse such narrative with reference to Pakistan’s continuous struggle for national identity. ‘The analyses propose that anti-secular voices are occupying centre stage in Pakistan, leaving little room for diverse opinions. Anti-secular groups use violence as a tool to silence any opposition against their ideology for Pakistan, which is evident by regular attacks on not only the religious minorities but also the moderate or liberal Muslim thinkers. The conflict over national identity between extremists and moderates is also one of the main causes of rising violent extremism in Pakistan. &nbsp

Minimizing the Age of Information in Wireless Networks with Stochastic Arrivals

We consider a wireless network with a base station serving multiple traffic streams to different destinations. Packets from each stream arrive to the base station according to a stochastic process and are enqueued in a separate (per stream) queue. The queueing discipline controls which packet within each queue is available for transmission. The base station decides, at every time t, which stream to serve to the corresponding destination. The goal of scheduling decisions is to keep the information at the destinations fresh. Information freshness is captured by the Age of Information (AoI) metric. In this paper, we derive a lower bound on the AoI performance achievable by any given network operating under any queueing discipline. Then, we consider three common queueing disciplines and develop both an Optimal Stationary Randomized policy and a Max-Weight policy under each discipline. Our approach allows us to evaluate the combined impact of the stochastic arrivals, queueing discipline and scheduling policy on AoI. We evaluate the AoI performance both analytically and using simulations. Numerical results show that the performance of the Max-Weight policy is close to the analytical lower bound

COVID-19 presenting with spontaneous pneumothorax

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease mainly affects respiratory system. Its common clinical findings include fever, cough and shortness of breath. Characteristic radiological features of the disease include peripherally distributed, bilateral ground-glass opacities, predominantly involving the lower lung zones. In this report, we present a case of COVID-19 disease presenting with spontaneous pneumothorax. A 26-year male patient was admitted to the Emergency Department with fever, dry cough, shortness of breath and right-sided chest pain. Radiographic imaging of the patient revealed pneumothorax on the right and peripherally distributed non-homogenous opacification. The patient underwent right lateral tube thoracostomy. COVID-19 was diagnosed on testing of nasopharyngeal swab. In conclusion, spontaneous pneumothorax is one of the rare presentations of COVID-19 pneumonia and should be kept in mind in patients presenting with shortness of breath and chest pain

Acetaminophen induced Steven Johnson syndrome-toxic epidermal necrolysis overlap

Steven Johnson Syndrome and Toxic Epidermal Necrolysis are rare but severe form of hypersensitivity inflammatory reactions to multiple offending agents including drugs. Acetaminophen is extensively used due to its analgesic and anti-pyretic properties. It is rendered to be relatively safe, with hepatotoxicity considered to be the major adverse effect. However, very few cases of Steven Johnson Syndrome and Toxic Epidermal Necrolysis have been reported with acetaminophen usage in the past. We present the case of a 40 years old lady who developed an overlap of the two condition after taking several doses of acetaminophen for fever. She presented with widespread maculopapular rash, stinging in the eyes, oral mucosal ulcerations and high grade fever. She was successfully treated with corticosteroid therapy along with the supportive treatment. This case addresses the fact, that severe hypersensitivity reactions can occur with acetaminophen which can be potentially life threatening

Water and Communities in South Asia: A Case for Regional Cooperation

Increased use of water for hydropower and agriculture, due to population growth accounts for future water shortages that will affect a quarter of South Asia’s population by 2050. Water crises affect all member-nations of the South Asian Association for Regional Cooperation (SAARC), namely Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka. SAARC nations water needs exacerbate the water crisis on the one hand and lack of mechanisms for good governance and cooperation required for addressing issues related to food and water security within the region. This paper attempts to draw attention to the big picture regarding water resources management and the impacts of water scarcity on South Asian nations. The paper begins with a review of the water crises in each of the SAARC nations and follows on with consideration of perceptions towards transboundary river infrastructures and the political stances each nation takes about solutions for the continuing water crisis. Undoubtedly, the only mechanism that these nations can adapt to address the geopolitical challenges of a thirsty world, for which SAARC association provides the platform is a deliberate constructive solution centred dialogue. A range of recommendations for SAARC nations are reviewed with a view to assist the water thirst in these nations

The perceived public value of social media in Queensland local Councils

Although many enterprises have been pursuing a digital strategy to facilitate larger and more diverse ecosystems in recent years, there are few successful examples of conglomeration of digital ecosystems through aligning or combining diverse ecosystems. Hybrid organizing is a sound guiding theory that we adopt to examine the nature of conglomeration of digital ecosystems. We construct a theoretical lens aligning hybridization approaches with forms of ecosystems through an organization design based on IT/IS capabilities. Guided by this lens, we conduct an in-depth case study of a successful company in China. This study reveals a process model towards conglomeration of digital ecosystems, which consists of dismissing, separating, and cumulating phases. Our findings contribute to existing body of literature, in the field of digital ecosystems, hybrid organizing and IT/IS capabilities. Core firms of ecosystems can use the model to design and develop digital ecosystems with rational deliberation and planning

Arsenic and fluoride removal from water using bone char

Dissolved arsenic and fluorine species co-occurrence in groundwater is of great global concern due to the consequences arising from daily exposure. Millions of people around the world are experiencing health issues as a result of water contamination, especially in developing countries. Therefore, exploring a cost-effective and environmentally friendly adsorbent using waste material has gained great interest in recent years. The use of animal waste from a growing meat industry, provides a sustainable energy source and environmental benefits by reducing the amount of waste material to be disposed. This study developed bone char and its composites using bone waste as the precursor. The initial objective was to study the effect of pyrolysis temperature (500, 650, 800 and 900 °C), variant residence time and purging gas on the characteristics of the bone char samples. The characteristics of these samples were compared using a range of analytical methods, which were used to interpret the mechanism of removal of fluoride (F-), arsenite [As(III)] and arsenate [As(V)] from water. The samples prepared at 900 °C had the highest removal capacity for As(III) and As(V) at 4.21 and 56.79 μg/g, respectively. On the other hand, a pyrolysis temperature of 650 °C was reported as the optimum temperature for the removal of F- from water. Using four different isotherm models (Langmuir, Freundlich, Redlich-Peterson and Sips), the experimental data relating to As(III) and As(V) removal from water under optimal conditions was found to follow the Sips and Langmuir model, respectively. The kinetic models were examined at 0.5, 2.5, 5 and 10 mg/L of initial concentration for both As(III) and As(V) using kinetic and diffusion models. It was found that the main controlling rate of the adsorption process was intraparticle diffusion, while pore diffusion’s contribution in the adsorption process was limited to the lower concentrations of 0.5 and 2.5 mg/L. The outcome of the study showed that the removal of As(III) and As(V) from water was complex. Bone char was found to have a higher removal capacity of As(III) at higher concentrations (>20 mg/L). Thus, modifications are required to either increase the As(III) uptake by the bone char samples or oxidize them to As(V) to provide higher removal capacities. The oxidation of As(III) to As(V) was examined by producing a composite through the coating of bone char (BC) with nanoscale titanium dioxide (nTiO2) as a photocatalyst. Two preparation methods were adopted for the coating process: after the pyrolysis process at 300 °C and during the pyrolysis process at 900 °C. The latter resulted in a phase change of the nTiO2 from anatase to rutile and showed higher As removal (57.3 % vs 24.8%) and oxidation efficiency (3.5 times more arsenate was produced) for both species compared to the composite prepared after the pyrolysis process. It was also found to have a higher removal capacity for both As species compared to unmodified bone char. The oxidation process was examined through the examination of three different levels of UV light (4, 8, and 12 W) during the experiment. By applying 12W of UV, a removal capacity of 281.36 μg/g was achieved for the composite, compared to the removal capacity of 195.76 μg/g using the uncoated BC900. For the individual and simultaneous removals of As(III), As(V) and F-, fixed bed columns packed with bone char were used to quantify influent flow rate and concentration on breakthrough time during the removal of these contaminants. Breakthrough time was found to decrease with the increase in flow rate and influent concentrations. Four models were used to fit the experimental data relating to the characteristic parameters of the columns: the Yoon-Nelson, Thomas, and Bohart and Adams models. The best fit was provided by the Yoon-Nelson and Thomas models. The presence of coexisting anions was examined and it was found that they resulted in a decreased As removal from water, with F- posing the most significant effect. The improvement in As removal from water was examined by applying capitative deionization (CDI) technology to the columns. Promising results were achieved as there was a significant increase in breakthrough time using this combination. This study confirms that valuable bone char and composites can be prepared from animal bio-waste to be utilized as adsorbents for various environmental applications. The structural and surface properties of bone char can be optimized by changing pyrolysis conditions to maximize the sorption capacity of the targeted contaminants