Modeling Electrolyte Solutions in a Statistical Associating Fluid Theory (SAFT) Framework

SAFT-VR Mie is one of the most recent extensions of Statistical Associating Fluid Theory (SAFT). It is based on the Mie potential, which is a generalized form of the Lennard-Jones potential in which the exponents of the repulsive and attractive terms are allowed to vary from 12 and 6, respectively. In this thesis, the latest formulation of SAFT-VR Mie is implemented to accurately calculate densities and phase equilibria of both associating and non-associating fluid mixtures. The model is subsequently extended to mixtures with strongly dissociating electrolytes in water through the addition of a Born term to account for solvation effects and a Debye-Hückel term for long-range, electrostatic interactions. A single adjustable parameter is assigned to each ionic species (the cross dispersion energy between the ion and solvent) and is optimized against experimental data for electrolyte solution densities and mean ionic activity coefficients using a sequential Nelder-Mead algorithm with a parallel objective function evaluation. Model correlations for the activity coefficients and liquid densities, as well as predictive calculations of vapor pressure, osmotic coefficients and mixed ion properties, show that the model’s performance is comparable to that of other recent formulations for electrolyte solutions. Further improvement in a subsequent generation of the proposed equation of state will likely derive from a better description of dielectric phenomena, and adjustments to the parameter optimization strategy

Construction Bidding and the Winner\u27S Curse

In the construction industry, the winner’s curse occurs when the winning contractor has underestimated the project’s true cost. Using a game and auction theory approach, this study aims to analyze - and potentially reduce - industry exposure to the effects of the winner\u27s curse in construction bidding. A simulation model for single and multi-stage bidding processes was developed and analyzed an actual dataset of California Department of Transportation projects. The majority of general contractors and sub-contractors suffer from the winner\u27s curse in both single and multi-stage bidding environments. The multi-stage bidding environment incurs more losses than the single-stage bidding environment. Through learning from past experiences though, the multi-stage bidding environment provides contractors with better opportunity to avoid the winner\u27s curse. Finally, it was shown that the symmetric risk neutral Nash equilibrium optimal bid function provides the contractors with a tool to avoid the winner\u27s curse and gain strategic positive profits

Data-Driven Analysis Of Construction Bidding Stage-Related Causes Of Disputes

Construction bidding is a complex process that involves several potential risks and uncertainties for all the stakeholders involved. Such complexities, risks, and uncertainties, if uncontrolled, can lead to the rise of claims, conflicts, and disputes during the course of a project. Even though a substantial amount of knowledge has been acquired about construction disputes and their causation, there is a lack of research that examines the causes of disputes associated with the bidding phase of projects. This study addresses this knowledge gap within the context of infrastructure projects. In investigating and analyzing the causation of disputes related to the bidding stage, the authors implemented a multistep research methodology that incorporated data collection, network analysis (NA), spectral clustering, and association rule analysis (ARA). Based on a manual content analysis of 94 legal cases, the authors identified a comprehensive list of 27 causes of disputes associated with the bidding stage of infrastructure projects. The NA results indicated that the major common causes leading to disputes in infrastructure projects comprise inaccurate cost estimates, inappropriate tender documents, nonproper or untimely notification of errors in a submitted bid, nonproper or untimely notification of errors in tender documents, and noncompliance with Request for Proposals\u27 (RFP) requirements. Upon categorizing and clustering the causes of disputes, the ARA results revealed that the most critical associations are related to differing site conditions, errors in submitted bids, unbalanced bidding, errors in cost estimates, and errors in tender documents. This study promotes an in-depth understanding of the causes of disputes associated with the bidding phase within the context of infrastructure projects, which should better enable the establishment of proactive plans and practices to control these causes as well as mitigate the occurrence of their associated disputes during project execution

An Epidemiological Study of Sheep and Goat pox Outbreaks in the Sudan

Sheep and goat pox Outbreaks occurred in different geographic areas of Sudan and most strikingly, were highly species specific. Two outbreaks in Gedarif State in June. 2013 affected no goats and outbreak in Khartoum state in March. 2015 affected no sheep despite communal herding; affected goats were vaccinated with 0240 strain. Clinically, the disease was characterized by fever, depression and eruption of generalized pox lesions. Mortality rate ranged between 5.2 and 6.7% with a mean of 6.1%. Isolation of viruses succeed on Lamb testes cell culture at passage four, the diseases were diagnosed using virus neutralisation test and polymerase chain reaction. Sheeppox and goatpox isolates grew well in lamb testes and Vero cells. In MDBK however, both viruses induced slight CPE that reached 60% in 9 days. On the other hand, both isolates induced no CPE in chick embryo fibroblast cells. Virus isolation attempts failed on chorioallantoic membrane of embryonated chicken eggs

Problems Faced and Difference in Quality of Life Among The Elderly Population of Suburban Areas of Twin Cities

Objective: To evaluate the problems faced and the difference in the quality of life among the elderly population of three suburban areas of twin cities of Pakistan.Setting and duration: This study was conducted in three suburban setting around Islamabad and Rawalpindi in a duration of six months from February to August 2017.Methodology: A total of 110 participants consisting on 55 males and 55 female were selected for the study. This cross sectional survey was conducted on a geriatric population of age more than 60 years. The elders having any disease, psychological or physical disorder were excluded from the study. In this study, we used the Quality of life Instruments developed by WHO (WHOQOL-BREF) which is a validated and one of the most widely used tools in QoL research. Informed consent was taken from all the participants prior to the study. The data form all the participants was collected through face to face interviews and entry with analysis was done through SPSS v. 21.Results: Majority 58 (52.73%) of the participants were of age interval of 60-64 years followed by 39 (35.45%) in the age group of 65-69 years. A large number 41 (37.27%) of elderly participants were uneducated. Most 63 (57.27%) of the participants of the study were living in the extended family system. Main bulk 49 (44.55%) of the study sample belonged to families having a monthly income of 16000-25000 rupees, followed by 25 (22.73%) families having an income of 26000-35000 rupees. The main source of income was a dependency on children. The most common 24 (21.82%) problem faced was related to financial issues, followed by loneliness 22 (20%). Majority 68 (61.82%) of the study sample replied that the bahaviour of family members is friendly and politely with them. The QoL score for physical health, psychological health, social relationship and environment were significantly higher in male participants as compared to female counterparts. The overall quality of life on the basis of the quality of life score QoL was significantly better in male participants as compared to female participants.  Conclusions: The overall quality of life on the basis of quality of life score QoL was significantly better in male participants as compared to female participants. Their busy children or family conflicts and misapprehensions instigate their miserable moments of older life

Immunological and Neurological Manifestations of COVID-19: An Intimate Relationship

Background: COVID-19 has superseded all medical scientific challenges in 2020. It presented with a range of respiratory involvement from the mild upper respiratory tract to severe pneumonia with ARDS. A percentage of these patients manifested variable neurological presentations expanding the challenges of patients’ assessment, care, and management. Objective: To discuss the neurological manifestations and the possible immunopathology of COVID-19. Methods: A literature search was performed in the PubMed database for the relevant articles published in English language between April 9th , 2020 and June 1, 2020. Few papers were extracted from Google Scholar and pre-print material as well. The keywords used to perform search included “COVID-19,” “SARS Cov2,” “neurological manifestations,” and “immunology and pathology of COVID-19”. However, animal studies were excluded in the neurological manifestations, and the final number of literature search outcome was 27 articles. Results: The immunopathology involves angiotensin-converting enzyme (ACE) receptor 2 and spike protein S1. COVID-19 has a tremendous affinity to the ACE2 receptor. The status of secondary hemophagocytic lymphohistiocytosis (sHLH) and the cytokine storm lead to different organ damage and the corresponding clinical manifestations. The documented neurological manifestations mainly include acute ischemic stroke, hemorrhagic stroke, temporal lobe, thalamic encephalitis, and one case of Guillain-Barre Syndrome, in addition to agitation, headache, and seizures. Conclusion: Although the intimate relationship between the neurons and the immune activation is the basic concept of COVID-19 immunopathology, the definite routes of entry to the neuronal cells are yet to be disclosed. Acute stroke, myositis, headache, and meningoencephalitis are the most common types of complications of COVID-19 so far

Management of Change Orders in Infrastructure Transportation Projects

The Illinois Department of Transportation (IDOT) will handle many upcoming projects due to the recent statewide infrastructure strategic plan and the fast-track efforts affecting many infrastructure projects amid COVID-19. Nevertheless, many change orders are anticipated to occur on IDOT\u27s projects. Thus, this paper examines the proper contractual management of changes within IDOT infrastructure transportation projects by following a research method based on the integration between a desktop analysis and a focus group analysis. The desktop analysis involved collecting information and data from existing resources, case studies, and documents related to change orders. The focus group analysis involved consulting with change order experts to verify that the outcome of each research step is useful and to validate the final outcomes of the paper. Based on 50 documented major change orders in IDOT projects and three litigated cases, two findings are provided. First, the top causes for key change orders within IDOT projects include contract administration, allowable contingencies, quantity omission or error, differing site conditions, and design changes. Second, the most critical change order related challenges within IDOT\u27s infrastructure projects include approval procedures, compensation considerations, and applicable laws. This paper offers flowcharts, synopsis of opportunities and risks, and a checklist to help the contracting parties better administer change orders. Ultimately, the contributions of this paper to the practice include: (1) minimizing the number and amount of change orders, (2) helping the contracting parties better understand how their individual responsibilities contribute to the proper processing and management of changes and variations, (3) offering contractors the ability to visualize the different steps involved in the approval of change orders, (4) assisting the project stakeholders in identifying change order-related areas for improvement, and (5) allowing project owners to better mitigate, manage, and administer the contractual aspects of change orders

Guillain-Barre syndrome associated with COVID-19 infection:A case series

In this communication, we reported a series of six patients presented with Guillain-Barré syndrome that associated with COVID-19 infection, which was confirmed with RT-PCR. Here we discuss the laboratory investigation and case management, as well as clinical presentation and outcome of each case. The current report demonstrated the first case series of COVID-19-associated GBS-cases in Sudan.</p

Guillain-Barre syndrome associated with COVID-19 infection:A case series

In this communication, we reported a series of six patients presented with Guillain-Barré syndrome that associated with COVID-19 infection, which was confirmed with RT-PCR. Here we discuss the laboratory investigation and case management, as well as clinical presentation and outcome of each case. The current report demonstrated the first case series of COVID-19-associated GBS-cases in Sudan.</p

Masalah Vape di Sekolah Dalam Kalangan Awal Remaja

Masalah tingkah laku vape dalam kalangan awal remaja iaitu remaja yang berumur 12 tahun ke bawah dan 12 tahun keatas adalah satu perkara yang membimbangkan di dalam kalangan pelajar sekolah di Malaysia. Objektif kajian ini iaitu untuk menghuraikan punca berlakunya masalah vape, mengenal pasti strategi, pendekatan atau cadangan untuk mengurangkan masalah vape di sekolah, mengenal pasti keberkesanan sesi kaunseling terhadap pelajar yang terlibat dalam gejala vape, mengenal pasti kesan vape ke atas pelajar peringkat awal remaja, dan untuk mengkaji tahap perkembangan masalah vape di sekolah. Kaedah kajian ini meliputi reka bentuk kajian, instrument kajian dan prosedur atau proses menganalisis data bagi menjawab persoalan-persoalan kajian yang telah dikemukakan lebih awal. Dapatan kajian yang boleh disimpulkan menurut Ustaz Tengku perkembangan vape disekolah adalah semakin meningkat dan ia sukar dikawal. Hal ini demikian kerana wujudnya vape yang sukar untuk dikenal. Fenomena penggunaan vape menjadi ikutan anak muda dan kanak-kanak. Hal ini amat membimbangkan kerana ia bertentangan dengan Pelan Strategik Kebangsaan Bagi Kawalan Tembakau 2015-2020 dengan misi menjadikan Malaysia negara bebas daripada sebarang bentuk amalan merokok menjelang 2045. Vape Problems in School among Early Teens Abstract: Vape behavior problems among early adolescents who are 12 and under 12 are a concern among Malaysian schoolchildren. The objectives of this study were to identify the causes of vape problems, identify strategies, approaches or recommendations for reducing vape problems in schools, identify the effectiveness of counseling sessions for students involved in vape symptoms, identify vape effects on early adolescent students, and to study the developmental stages of vape problems in schools. The research methods include study design, instrumentation and data analysis procedures or processes to answer the research questions that were presented earlier. The findings of the study that can be concluded according to Ustaz Tengku the development of vape school are increasing and it is difficult to control. This is because of the vape that is difficult to identify. The phenomenon of the use of vape has been traced to young people and children. This is alarming as it goes against the National Strategic Plan for Tobacco Control 2015-2020 with the mission of making Malaysia a country free from any form of smoking by 2045. Keywords: Early Teens, School, Vape