pH Development Analysis of Alkaline and Low Salinity Water Flooding in sandstone cores

Master's thesis in Petroleum EngineeringLow salinity (LS) water flooding has been in the center of interest for conventional oil recovery in sandstone reservoir for more than two decades because of its low cost and potential for increased oil recovery. Though hundreds of researches have been done on LS EOR method, the mechanism behind the oil recovery is still debatable. Recently, Smart Water group of University of Stavanger has proposed a new chemical wettability alteration mechanism where protons (H+) from LS water replaces metal ions such as Ca2+, Na+ from the clay surface and made the surface more water wet by releasing polar organic oil components due to a pH increase. As a result, more oil is displaced towards production well and increases oil recovery. As the proton (H+) is adsorbed, pH of the produced water is increased and using this theory, Aksulu et. al. (2012) established a pH screening test as an experimental tool to check the LS potential for sandstone. pH of the system can also be increased by injecting alkaline water of high pH instead of creating in situ pH increase by LS water flooding. In this thesis, the transportability of alkalinity and development of pH was investigated for LS and alkaline water flooding. Three outcrop sandstone cores of different mineralogy were used for 12 pH screening tests at different temperatures. In addition with the pH screening test, pressure changes, density changes and ion chromatography tests were done during the flooding to observed the changes of produced water. pH-screening tests with alkaline water injection showed low potential for extra alkalinity compared with LS water injection. Almost two pH unit of injected high alkaline water is reduced by the minerals and formation water. On the other hand, the results of the pH-screening tests for LS water injection showed a potential for increasing the effluent LS water pH up to two units in comparison to its initial pH-value. Both the LS and alkaline water showed same trend of pH buildup though they had a big difference in bulk pH (almost 5 pH unit). Transportation of alkalinity through a mineral system with large surface area seemed to be challenging due to pH buffering from brine/mineral interactions as well as from chemical interactions involving inorganic cations from the formation water. It can be concluded after the thesis that an in-situ generation of alkaline conditions in the reservoir by injecting LS water seemed to have a larger potential for EOR purposes than transporting alkalinity by injecting high pH alkaline water through the reservoir

Outbreak of diarrheal diseases causes mortality in different geographical locations of Bangladesh during the 2021 COVID-19 era

ObjectivesDiarrhea is a major public health problem in low- and middle-income countries, including Bangladesh. Of the different spectrums of diarrheal diseases, cholera occurs every year, causing outbreaks and epidemics following a biannual seasonal pattern. Due to the COVID-19 pandemic, hospitalization for diarrheal diseases decreased in 2020 compared to the previous years. However, in 2021, massive outbreaks occurred in different geographical locations of the country. We described that an outbreak of diarrheal diseases causes mortality in different geographical locations in Bangladesh.MethodIn this study, we present a report of diarrhea outbreaks that were reported in 2018–2021 in different parts of Bangladesh, and data have been captured from different sources such as print and electronic media as well as from a nationwide surveillance system.ResultsAmong these locations, districts of Barisal Division, Kishorganj, Noakhali, Gopalganj, Bandarban, and Chattogram were the major hotspots of the outbreaks where high morbidity due to acute watery diarrhea and even mortality, which is usually low in Bangladesh, were recorded.ConclusionEarly detection and prevention and strengthening of the surveillance system are needed to combat the diarrheal upsurge, take immediate control, and adopt preventive strategies

A Study on Life Cycle Analysis (LCA) of a Cotton Woven Shirt

The property of textile materials has gained a lot of attention thanks to the resource consumption and wastematerial emissions at the moment time. So, it's terribly essential and a core demand to gauge theenvironmental result of textiles from a life cycle perspective to develop the property of textiles.Environmental problems became vital over the previous few years owing to increasing pollution, wastematerials, heating, etc. shoppers have additionally begun to demand inexperienced products. As a result ofthese events, additional strategic and systematic approaches square measure necessary for ever-changingenvironmental problems. Life Cycle Analysis (LCA) is one of the tools to satisfy this necessity. During thisresearch, we have a tendency to square measure analyzing the LCA of a ‘Cotton woven Shirt’, andscientifically evaluating the environmental impacts also as resource utilization to supply, from raw materialsto the disposal of the merchandise at the top of life

Comparative Analysis among Different ZnO Nanoparticles Synthesized by Different Techniques

Semiconductor oxides were synthesized and systematically examined on 100 % cotton fabric to optimize the properties. Nano-technology is employed in this research work to form nanoparticles of semi-conductor oxides. Four samples were synthesized by using different methods and dyed to find the effective one. Different characterization techniques are used to characterize nanoparticles e.g. X-ray powder diffractometer, Energy dispersive X-ray spectroscope (EDS, EDX or EDXRF) and SEM images. By examining diffraction pattern and SEM images homogeneity, crystalline phase, transparent finishing process and unit cell dimensions are found. ZnO-3 (sample 3) (TEA 0.025M) treated cotton is revealed to have unique properties and implied a transparent finishing process

In-Vitro Study of Low Viscosity, and High Viscosity Direct Compression and conventional Grade Hypromellose for Modified Release Gliclazide tablets

Six different low to high viscosity hypromellose were used with lower soluble Gliclazide, alone to investigate the dissolution study and flow property. Dissolution behavior of formulated tablets was tested to identify the better efficacy. Dose dumping, pH dependency also was examined. Anti-diabetic Gliclazide tablets were prepared by direct compression method and the results of dissolution was found good in Methocel K100M DC for 73.25%. Tablets showed uniform weight, thickness, and lower percent ( 0.5%) friability. Result of Carrs index and Hausner ratio indicated good flow properties of powder granules. The percent release of the Gliclazide was analyzed by kinetic models. Release of the drug was higher using the higher viscosity grade. Gliclazide tablets were determined with the goodness of fit test of kinetic models. The release showed linearity in Higuchi Model with correlation coefficient value of R 2 = 0.973. In-vitro study demonstrated improved release profile using DC grade than CR grade alone

A Computational analysis on Lectin and Histone H1 protein of different pulse species as well as comparative study with rice for balanced diet

The issue of balanced nutrition is of great concern to human. Meat and fish are the best sources of protein. The affordability of these resources for people in developing countries is less. Thus, there is an increasing interest in pulses and its derivates as an alternative to fish and meat. Lectin and histone H1 are the most common proteins in various pulses and our interest is in identifying the dominant essential amino acids in them for use as supplements. However, actin and lectin are common among Oryza Sativa and cicer arietinum. We describe the amount of lectin and histone H1 in cicer arietinum, Lens culinaris and Pisum sativum in a comparative manner. cicer arietinum was found to contain more essential amino acids than Lens culinaris and Pisum sativum. The secondary structures of lectin and histone H1 protein were analyzed to gain functional inferences in these species. The comparative study shows the relatively poor presence of the amino acid methionine in most pulses. However, Oryza Sativa was found to contain sufficient methionine. The study shows that pulses (especially cicer arietinum) were a suitable alternative source to meat and fish for Lectin and Histone H1 balance. Hence, pulses could be suggested with rice for balanced protein diet

Polysulphate: A New Enhanced Oil Recovery Additive to Maximize the Oil Recovery From Carbonate Reservoirs at High Temperature

Seawater (SW) injection is an enhanced oil recovery (EOR) success in the North Sea carbonate reservoirs due to wettability alteration toward a more water-wet state. This process is triggered by the difference in composition between injection and formation water (FW). “Smartwater” with optimized ionic composition can easily be made under laboratory conditions to improve oil recovery beyond that of SW. However, in the field, its preparation may require specific water treatment processes, e.g., desalination, nanofiltration, or addition of specific salts. In this work, a naturally occurring salt called Polysulphate (PS) is investigated as an additive to produce smartwater. Outcrop chalk from Stevns Klint (SK), consisting of 98% biogenic CaCO3, was used to investigate the potential and efficiency of the PS brines to alter wettability in chalk. The solubility of PS in SW and deionized water, and brine stability at high temperatures were measured. Energy dispersive X-ray and ion chromatography were used to determine the composition of the PS salt and EOR solutions, and to evaluate the sulphate adsorption on the chalk surface, a catalyst for the wettability alteration process. Spontaneous imbibition (SI), for evaluating wettability alteration of PS brines into mixed-wet chalk was performed at 90 and 110°C and compared against the recovery performance of FW and SW. The solubility tests showed that the salt was easily soluble in both deionized water and SW with less than 5% solid residue. The deionized PS brine contained sulphate and calcium ion concentrations of 31.5 and 15.2 mM, respectively, and total salinity was 4.9 g/L. This brine composition is very promising for triggering wettability alteration in chalk. The SW PS brine contained 29.6 mM calcium ions and 55.9 mM sulphate ions, and a total salinity of 38.1 g/L. Compared with ordinary SW, this brine has the potential for improved wettability alteration in chalk due to increased sulphate content. Ion chromatography revealed that the sulphate adsorbed when PS brines were flooded through the core, which is an indication that wettability alteration can take place during brine injection. The reactivity was also enhanced by increasing the temperature from 25 to 90°C. Finally, the oil recovery tests by SI showed that PS brines were capable of inducing wettability alteration, improving oil recovery beyond that obtained by FW imbibition. The difference in oil recovery between ordinary SW and SW PS imbibition was smaller due to the already favorable composition of SW. PS brines showed a significant potential for wettability alteration in carbonates and are validated as a potential EOR additive for easy and on-site preparation of smartwater brines for carbonate oil reservoirs. PS salt, added to the EOR solution, provides the essential ions for the wettability alteration process, but further optimization is needed to characterize the optimal mixing ratios, ion compositions, and temperature ranges at which EOR effects can be achieved.publishedVersio

An Approach to Improve the Performance of Mobile Computation Technology Using Data Offloading

Modern mobile phones have a powerful processing unit that can perform multiple operations simultaneously. But the main constrain is the processing power and energy required to drive it. Cloud computing has come as a blessing for the mobile computing as it possesses a vast resource, high storage capacity and high processing power. In Mobile Cloud Computing (MCC), computation is offloaded to the cloud, cloud processes the data and generates information; and sends it back to the mobile device. Probability of offloading depends on line bandwidth, line length, size of data, processing speed of mobile, processing speed of cloud, storage and energy capacity of mobile etc. This paper presents a model for efficient data offloading decision, depending on the total execution time of a task when the data computation happens in the mobile and when it is offloaded to the cloud. An algorithm has been proposed here on data offloading decision. As thus an equation has been proposed to observe the probability of offloading process

Use of oral cholera vaccine as a vaccine probe to determine the burden of culture-negative cholera.

Analyses of stool from patients with acute watery diarrhea (AWD) using sensitive molecular diagnostics have challenged whether fecal microbiological cultures have acceptably high sensitivity for cholera diagnosis. If true, these findings imply that current estimates of the global burden of cholera, which rely largely on culture-confirmation, may be underestimates. We conducted a vaccine probe study to evaluate this possibility, assessing whether an effective killed oral cholera vaccine (OCV) tested in a field trial in a cholera-endemic population conferred protection against cholera culture-negative AWD, with the assumption that if cultures are indeed insensitive, OCV protection in such cases should be detectable. We re-analysed the data of a Phase III individually-randomized placebo-controlled efficacy trial of killed OCVs conducted in Matlab, Bangladesh in 1985. We calculated the protective efficacy (PE) of a killed whole cell-only (WC-only) OCV against first-episodes of cholera culture-negative AWD during two years of post-dosing follow-up. In secondary analyses, we evaluated PE against cholera culture-negative AWD by age at vaccination, season of onset, and disease severity. In this trial 50,770 people received at least 2 complete doses of either WC-only OCV or placebo, and 791 first episodes of AWD were reported during the follow-up period, of which 365 were culture-positive for Vibrio cholerae O1. Of the 426 culture-negative AWD episodes, 215 occurred in the WC group and 211 occurred in the placebo group (adjusted PE = -1.7%; 95%CI -23.0 to 13.9%, p = 0.859). No measurable PE of OCV was observed against all or severe cholera culture-negative AWD when measured overall or by age and season subgroups. In this OCV probe study we detected no vaccine protection against AWD episodes for which fecal cultures were negative for Vibrio cholera O1. Results from this setting suggest that fecal cultures from patients with AWD were highly sensitive for cholera episodes that were etiologically attributable to this pathogen. Similar analyses of other OCV randomized controlled trials are recommended to corroborate these findings

Protection conferred by typhoid fever against recurrent typhoid fever in urban Kolkata.

We evaluated the protection conferred by a first documented visit for clinical care of typhoid fever against recurrent typhoid fever prompting a visit. This study takes advantage of multi-year follow-up of a population with endemic typhoid participating in a cluster-randomized control trial of Vi capsular polysaccharide typhoid vaccine in Kolkata, India. A population of 70,566 individuals, of whom 37,673 were vaccinated with one dose of either Vi vaccine or a control (Hepatitis A) vaccine, were observed for four years. Surveillance detected 315 first typhoid visits, among whom 4 developed subsequent typhoid, 3 due to reinfection, defined using genomic criteria and corresponding to -124% (95% CI: -599, 28) protection by the initial illness. Point estimates of protection conferred by an initial illness were negative or negligible in both vaccinated and non-vaccinated subjects, though confidence intervals around the point estimates were wide. These data provide little support for a protective immunizing effect of clinically treated typhoid illness, though modest levels of protection cannot be excluded