Flow and Transport in Unsaturated Porous Media: Fractal Modeling, Analytical Solutions and Experimentation

This dissertation consists of five parts, each describing a specific topic of unsaturated flow and transport. The first three parts describe the development of soil hydraulic function models with the effects of partial drainage by using fractal and probabilistic approaches. During drainage of a porous medium, both the pore size distribution and the connectivity of pores determine the drained pore volume as function of suction. New analytical expressions were presented for the water retention (part 1), intrinsic permeability (part 2), and relative permeability (part 3) functions. Predictions based on the analytical models are compared with estimates of the intrinsic permeability (k) derived from lattice Boltzmann method (LBM) simulations of saturated flow in virtual representations of classical (deterministic) and randomized Menger Sponges. Overall, the analytically predicted k values matched the k values from the LBM simulations with less than 14% error for deterministic sponges with minimum pore sizes ranging from 1/31 to 1/34. We presented a new approach that allows the prediction of relative permeability by direct use of measured water retention data without fitting. This new discrete model describes the drained pore space and permeability at different suctions incorporating the effect of both pore size distribution and connectivity among water-filled pores. We tested the performance of the new model by comparing its predictions of relative permeability to those of van Genuchten-Mualem (VG-M). Overall, the new method (RMSE=0.175, LRMSE=1.101) predicted the measured relative permeability data better than the VG-M model (RMSE=0.216, LRMSE=2.381). Part 4 presents analytical solutions of the advective solute transport in a macropore with simultaneous diffusion into an unbounded soil matrix. We obtained three sets of exact and approximate solutions for various boundary and initial conditions. Part 5 presents a moisture moment method to estimate unsaturated soil hydraulic properties. By analyzing the change in forces of two load cells that suspend either end of a soil column and the inlet water pressure, the unsaturated hydraulic conductivity and water retention functions are obtained. We applied the method to a sandy silt loam and the analyses show the method is promising

The comparison between dual inhibition of mTOR with MAPK and PI3K signaling pathways in KRAS mutant NSCLC cell lines

KRAS mutations are found in 15–25 % of patients with lung adenocarcinoma, and they lead to constitutive activation of KRAS signaling pathway that results in sustained cell proliferation. Currently, there are no direct anti-KRAS therapies available. Therefore, it is rational to target the downstream molecules of KRAS signaling pathway, which are mitogenactivated protein kinase (MAPK) signaling pathway (RAFMEK- ERK) and PI3K pathway (PI3K-AKT-mTOR). Here, we examined the inhibition of both these pathways alone and in combination and analyzed the anti-proliferative and apoptotic events in KRAS mutant NSCLC cell lines, A549 and Calu-1. Cytotoxicity was determined by MTT assay after the cells were treated with LY294002 (PI3K inhibitor), U0126 (MEK inhibitor), and RAD001 (mTOR inhibitor) for 24 and 48 h. The expression levels of p-ERK, ERK, AKT, p-AKT, p53, cyclinD1, cmyc, p27kip1, BAX, BIM, and GAPDH were detected by western blot after 6 and 24 h treatment. Although PI3K/mTOR inhibition is more effective in cytotoxicity in A549 and Calu-1 cells, MEK/mTOR inhibition markedly decreases cell proliferation protein marker expressions. Our data show that combined targeting of MEK and PI3K-AKTwith mTOR is a better option than single agents alone forKRASmutantNSCLC, thus opening the possibility of a beneficial treatment strategy in the future

Experimental and numerical simulation of water adsorption and diffusion in shale gas reservoir rocks

Despite the success of deep horizontal drilling and hydraulic fracturing in yielding large production increases from unconventional shale gas reservoirs, uncertainties associated with basic transport processes require understanding in order to improve efficiency and minimize environmental impacts. The hydraulic fracturing process introduces large volumes of water into shale gas reservoirs, most of which remains unrecoverable and interferes with gas production. In this study, the water adsorption and diffusion measurements of the Longmaxi Formation shale were conducted at 30℃ and 50℃for relative humidities from 11.1% to 97.0%. Based on the experiment, a computational model based on the Maxwell-Stefan diffusion equation was constructed to analyze water adsorption and diffusion in shale rocks, and the Guggenheim-Anderson-de Boer (GAB) isotherm for gas adsorption was included in the model. The results show that water adsorption isotherms of shales belong to type II curve, including the monolayer, multilayer adsorption and capillary condensation, and the GAB model can be used to describe the water adsorption process in shale rocks. With the increasing of relative pressure, the water adsorption of shale increases, and the organic carbon content and temperature strengthen the water adsorption in shale. The capillary pressure can reach the order of several hundreds of MPa after the hydraulic fracturing process, and it results in a large amount of fracturing fluid retained in shale gas reservoirs. Furthermore, the simulations of water adsorption and diffusion in shale rocks is less than the experimental value, which further indicates that capillary condensation occurs in shale rocks.Cited as: Shen, W., Li, X., Cihan, A., Lu, X., Liu, X. Experimental and numerical simulation of water adsorption and diffusion in shale gas reservoir rocks. Advances in Geo-Energy Research, 2019, 3(2): 165-174, doi: 10.26804/ager.2019.02.0

Experimental and numerical simulation of water adsorption and diffusion in shale gas reservoir rocks

Despite the success of deep horizontal drilling and hydraulic fracturing in yielding large production increases from unconventional shale gas reservoirs, uncertainties associated with basic transport processes require understanding in order to improve efficiency and minimize environmental impacts. The hydraulic fracturing process introduces large volumes of water into shale gas reservoirs, most of which remains unrecoverable and interferes with gas production. In this study, the water adsorption and diffusion measurements of the Longmaxi Formation shale were conducted at 30℃ and 50℃for relative humidities from 11.1% to 97.0%. Based on the experiment, a computational model based on the Maxwell-Stefan diffusion equation was constructed to analyze water adsorption and diffusion in shale rocks, and the Guggenheim-Anderson-de Boer (GAB) isotherm for gas adsorption was included in the model. The results show that water adsorption isotherms of shales belong to type II curve, including the monolayer, multilayer adsorption and capillary condensation, and the GAB model can be used to describe the water adsorption process in shale rocks. With the increasing of relative pressure, the water adsorption of shale increases, and the organic carbon content and temperature strengthen the water adsorption in shale. The capillary pressure can reach the order of several hundreds of MPa after the hydraulic fracturing process, and it results in a large amount of fracturing fluid retained in shale gas reservoirs. Furthermore, the simulations of water adsorption and diffusion in shale rocks is less than the experimental value, which further indicates that capillary condensation occurs in shale rocks

Possible Ototoxic Effects of Topical Rifamycin Application: An Electrophysiological and Ultrastructural Study

Objective:This study aimed to investigate possible ototoxicity associated with topical rifamycin application via electrophysiological tests and ultrastructural examinations.Methods:Electrophysiological assessment was performed with tympanometry, auditory brainstem response (ABR), and distortion product otoacoustic emission (DPOAE) measurements. This study was conducted on 40 ears of 20 guinea pigs that were detected to have normal hearing thresholds. The animals were randomly assigned to three groups: Group 1 (n=12) received 0.1 mL rifamycin, Group 2 (n=8) received 0.1 ml gentamycin, and Group 3 (n=20) received 0.1 mL physiological saline. The antibiotics and saline solutions were administered via intratympanic injections. After five injections every other day, electrophysiological tests were performed again on the 15th day. After electrophysiological measurements, the temporal bones of all guinea pigs were prepared for ultrastructural examinations and the cochlear surface morphology was examined by scanning electron microscopy (SEM).Results:The animals in group 3 did not show a statistically significant change in their DPOAE signal/noise ratio (SNR) or ABR thresholds (p>0.05). In groups 1 and 2, the reduction in the DPOAE SNR and the increase in the ABR threshold were statistically significant (p0.05).Conclusion:The results indicate that rifamycin application to the middle ears of guinea pigs has mild ototoxic effects on their inner ears

Evaluation of the rate of thrombocytosis in lower respiratory tract and upper urinary system ınfections

Alt solunum yolu enfeksiyonları ve üst üriner sistem enfeksiyonlarında trombositoz oranlarının çıkarılması ve degerlendirilmesi amaçlanmıstır. Bu çalısmada “GATAHaydarpasa Egitim Hastanesi Çocuk Klinigi'nde” 1 Ocak 2006- 1 Ocak 2009 yılları arasında yatırılarak tedavi verilen 20 alt solunum yolu enfeksiyonu (ASYE) ve 22 üst üriner sistem enfeksiyonu (ÜÜSE) tanısı alan hastanın dosyaları retrospektif olarak incelendi. Reaktif trombositoz, genel olarak kabul gören trombosit sayısının 500.000/mm üzeri olması kabul edildi. Istatistiksel veriler SPSS 13.0 ile degerlendirildi. Çalısmamızda trombositoz tanı anında üst üriner sistem enfeksiyonlarında daha fazla bulundu (ASYE %25, ÜÜSE %36). Üst üriner sistem enfeksiyonlarında en sık üreyen mikroorganizma Escherichia coli (n:12 %54) olarak tespit edildi. Çalısmamızda, alt solunum yolu enfeksiyonu ve üst üriner sistem enfeksiyonunda tanı anında görülen reaktif trombositoz ile hastalık siddeti karsılastırılmıs, arasında istatistiksel olarak anlamlı bir iliski bulunamamıstır.To evaluate the rates of thrombocytosis in lower respiratory tract (LRTI) and upper urinary system infections (UUSI). In this study, rates of thrombocytosis were evaluated in patients hospitalized and treated with the diagnosis of LRTI (n=20) or UUSI (n=22) in “GATA Haydarpasa Teaching Hospital, Department of Pediatrics” between 2006-2009, retrospectively. Reactive thrombocytosis is defined as the platelet count over 500.000/mm . Statistical analysis was performed by SPSS forWindows version 13.0. p'0.05 was accepted as statistically significant. Thrombocytosis was found to be higher in the UUSI (%36) at the time of the diagnosis compared to the LRTI group (25%). The most common microorganism identified in the UUSI was Escherichia coli (n=12, 54%). There was no significant relationship between the reactive thrombocytosis observed at the time of the diagnosis and the severity of the disease in theLRTI and the UUSI

The effect of post-wildfire management practices on vegetation recovery: Insights from the Sapadere fire, Antalya, Türkiye

Post-wildfire management actions mainly targeting the removal of salvage logs and burned trees is a common but controversial practice. Although it aims to regain some of the natural and economic value of a forest, it also requires disturbing burned areas, which may have some negative consequences affecting, for instance, the carbon cycle, soil erosion, and vegetation cover. Observations from different geographic settings contribute to this scientific debate, and yet, the spatiotemporal evolution of the post-fire road network developed as part of fire management practices and its influence on vegetation recovery has been rarely examined. Specifically, we still lack observations from Türkiye, though wildfires are a common event. This research examined the evolution of the vegetation cover in relation to post-fire road constructions and the resultant debris materials in areas affected by the 2017 Sapadere fire in Antalya, Türkiye. We used multi-sensor, multi-temporal optical satellite data and monitored the variation in both vegetation cover and road network from the pre-to post-fire periods between 2014 and 2021. Our results showed that fire management practices almost doubled the road network in the post-fire period, from 487 km to 900 km. Overall, 7% of the burned area was affected by these practices. As a result, vegetation cover in those areas shows only ∼50% recovery, whereas undisturbed areas exhibit ∼100% recovery 5 years after the event. Notably, such spatiotemporal analysis carried out for different burned areas would provide a better insight into the most suitable post-fire management practices. Our findings, in particular, show that the current practices need to be revisited as they cause a delay in vegetation recovery

Imaging and quantification of spreading and trapping of carbon dioxide in saline aquifers using meter-scale laboratory experiments

The role of capillary forces during buoyant migrati on of CO2 is critical towards plume immobilization within the post-injection phase of a geological carbon sequestration operation. However, the inherent heterogeneity of the subsurface makes it very challenging to evaluate the effects of capillary forces on the storage capacity of these formations and to assess in-situ plume evolution. To overcome the lack of accurate and continuous observations at the field scale and to mimic vertical migration and entrapment of realistic CO2 plumes in the presence of a background hydraulic gradient, we conducted two unique long-te rm experiments in a 2.44 m × 0.5 m tank. X-ray attenuation allowed measuring the evolution of a CO2-surrogate fluid saturation, thus providing direct insight into capillarity- and buoyancy-domin ated flow processes occurring under successive drainage and imbibition conditions. The comparison of saturation distributions between two experimental campaigns suggests that layered-type h eterogeneity plays an important role on non- wetting phase (NWP) migration and trapping, because it leads to (i) longer displacement times (3.6 months vs. 24 days) to reach stable trapping c onditions, (ii) limited vertical migration of the plume (with center of mass at 39% vs. 55% of aquife r thickness), and (iii) immobilization of a larger fraction of injected NWP mass (67.2% vs. 51. 5% of injected volume) as compared to the homogenous scenario. While these observations confirm once more the role of geological heterogeneity in controlling buoyant flows in the s ubsurface, they also highlight the importance of characterizing it at scales that are below seismic resolution (1-10 m)

Unusual presentation of eosinophilic fasciitis: two case reports and a review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Eosinophilic fasciitis is an uncommon disorder with unknown etiology and a poorly understood pathogenesis. We present the cases of two patients with eosinophilic fasciitis with unusual presentation, and describe the clinical characteristics and laboratory findings related to them.</p> <p>Case presentation</p> <p>The first case involves a 29-year-old Turkish man admitted with pain, edema and induration of his right-upper and left-lower limbs. Unilateral edema and stiffness with prominent pretibial edema was noted upon physical examination. A high eosinophil count was found on the peripheral smear. The second case involves a 63-year-old Turkish man who had pain, edema, erythema, and itching on his upper and lower extremities, which developed after strenuous physical activity. He had cervical lymphadenopathy and polyarthritis upon physical examination, and rheumatoid factor and antinuclear antibody upon laboratory examination.</p> <p>Conclusion</p> <p>Eosinophilic fasciitis can present with various symptoms. When patients exhibit eosinophilia, arthralgia and myalgia, eosinophilic fasciitis should be considered as a possible diagnosis.</p