Search results for: methane injection

Authors: Papon Thamvasupong, Kwanchanok Viravaidya-Pasuwat

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Osteoarthritis affects a lot of people worldwide. Local injection of glucosamine is one of the alternative treatment methods to replenish the natural lubrication of cartilage. However, multiple injections can potentially lead to possible bacterial infection. Therefore, a drug delivery system is desired to reduce the frequencies of injections. A hydrogel is one of the delivery systems that can control the release of drugs. Thermo-reversible hydrogels can be beneficial to the drug delivery system especially in the local injection route because this formulation can change from liquid to gel after getting into human body. Once the gel is in the body, it will slowly release the drug in a controlled manner. In this study, various formulations of Pluronic-based hydrogels were synthesized for the controlled release of glucosamine. One of the challenges of the Pluronic controlled release system is its fast dissolution rate. To overcome this problem, alginate and calcium sulfate (CaSO₄) were added to the polymer solution. The characteristics of the hydrogels were investigated including the gelation temperature, gelation time, hydrogel dissolution and glucosamine release mechanism. Finally, a mathematical model of glucosamine release from Pluronic-alginate-hyaluronic acid hydrogel was developed. Our results have shown that crosslinking Pluronic gel with alginate did not significantly extend the dissolution rate of the gel. Moreover, the gel dissolution profiles and the glucosamine release mechanisms were best described using the zeroth-order kinetic model, indicating that the release of glucosamine was primarily governed by the gel dissolution.

Keywords: controlled release, drug delivery system, glucosamine, pluronic, thermoreversible hydrogel

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Authors: Ariadna Manresa, Ines Ferrer

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Introduction: Ultrasonic moulding process (USM) is a recent injection technology used to manufacture micro components. It is able to melt small amounts of material so the waste of material is certainly reduced comparing to microinjection molding. This is an important advantage when the materials are expensive like medical biopolymers. Micro-scaled components are involved in a variety of uses, such as biomedical applications. It is required replication fidelity so it is important to stabilize the process and minimize the variability of the responses. The aim of this research is to investigate the influence of the main process parameters on the filling behaviour, the dimensional accuracy and the cavity pressure when a micro-plate is manufactured by biomaterials such as PLA and PCL. Methodology or Experimental Procedure: The specimens are manufactured using a Sonorus 1G Ultrasound Micro Molding Machine. The used geometry is a rectangular micro-plate of 15x5mm and 1mm of thickness. The materials used for the investigation are PLA and PCL due to biocompatible and degradation properties. The experimentation is divided into two phases. Firstly, the influence of process parameters (vibration amplitude, sonotrodo velocity, ultrasound time and compaction force) on filling behavior is analysed, in Phase 1. Next, when filling cavity is assured, the influence of both cooling time and force compaction on the cavity pressure, part temperature and dimensional accuracy is instigated, which is done in Phase. Results and Discussion: Filling behavior depends on sonotrodo velocity and vibration amplitude. When the ultrasonic time is higher, more ultrasonic energy is applied and the polymer temperature increases. Depending on the cooling time, it is possible that when mold is opened, the micro-plate temperature is too warm. Consequently, the polymer relieve its stored internal energy (ultrasonic and thermal) expanding through the easier direction. This fact is reflected on dimensional accuracy, causing micro-plates thicker than the mold. It has also been observed the most important fact that affects cavity pressure is the compaction configuration during the manufacturing cycle. Conclusions: This research demonstrated the influence of process parameters on the final micro-plated manufactured. Future works will be focused in manufacturing other geometries and analysing the mechanical properties of the specimens.

Keywords: biomaterial, biopolymer, micro injection molding, ultrasound

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Authors: Gregor Moncrieff, Ursula Bahlmann

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A number of incident reports were filed from the intensive care unit with regards to adult patients admitted following operations who had a central venous catheter inserted of the incorrect length for the relevant anatomical site and catheters not compatible with pressurised injection inserted whilst in theatre. Incorrect catheter length can lead to a variety of complications and pressurised injection is a requirement for contrast enhanced computerised tomography scans. This led to several patients having a repeat procedure to insert a catheter of the correct length and also compatible with pressurised injection. This project aimed to identify the types of central venous catheters used in theatres and ensure the correct equipment would be stocked and used in future cases in accordance the existing Association of Anaesthetics of Great Britain and Northern Ireland guidelines. A questionnaire was sent out to all of the anaesthetic department in our hospital aiming to determine what types of central venous catheters were preferably used by anaesthetists and why these had been chosen. We also explored any concerns regarding introduction of standardised, pressure injectable central venous catheters to the theatre department which were already in use in other parts of the hospital and in keeping with national guidance. A total of 56 responses were collected. 64% of respondents routinely used a central venous catheter which was significantly shorter than the national recommended guidance with a further 4 different types of central venous catheters used which were different to other areas of the hospital and not pressure injectable. 75% of respondents were in agreement to standardised introduction of the pressure injectable catheters of the recommended length in accordance with national guidance. Reasons why 25% respondents were opposed to introduction of these catheters were explored and discussed. We were successfully able to introduce the standardised central catheters to the theatre department following presentation at the local anaesthetic quality and safety meeting. Reasons against introduction of the catheters were discussed and a compromise was reached that the existing catheters would continue to be stocked but would only be available on request, with a focus on encouraging use of the standardised catheters. Additional changes achieved included removing redundant catheters from the theatre stock. Ongoing data is being collected to analyse positive and negative feedback from use of the introduced catheters.

Keywords: central venous catheter, medical equipment, medical safety, quality improvement

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Authors: Rizwan Latif, Syed Adnan Qasim, Muzaffar Ali

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Fuel direct injection represents one of the key aspects in the development of the diesel engines, the idea of controlling the auto-ignition and the consequent combustion of a liquid spray injected in a reacting atmosphere during a time scale of few milliseconds has been a challenging task for the engine community and pushed forward to a massive research in this field. The quality of the air-fuel mixture defines the combustion efficiency, and therefore the engine efficiency. A droplet interaction in dense as well as thin portion of the spray receives equal importance as other parameters in spray structure. Usually, these are modeled along with breakup process and analyzed alike. In this paper, droplet interaction is modeled and simulated for high torque low speed scenario. Droplet interactions may further be subdivided into droplet collision and coalescence, spray wall impingement, droplets drag, etc. Droplet collisions may occur in almost all spray applications, but especially in diesel like conditions such as high pressure sprays as utilized in combustion engines. These collisions have a strong influence on the mean droplet size and its spatial distribution and can, therefore, affect sub-processes of spray combustion such as mass, momentum and energy transfer between gas and droplets. Similarly, for high-pressure injection systems spray wall impingement is an inherent sub-process of mixture formation. However, its influence on combustion is in-explicit.

Keywords: droplet collision, coalescence, low speed, diesel fuel

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Authors: Jithin S. Kumar, Ramesh Kannan Kandasami

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Geomaterials are generally porous in nature due to the presence of discrete particles and interconnected voids. The porosity present in these geomaterials play a critical role in many engineering applications such as CO2 sequestration, well bore strengthening, enhanced oil and hydrocarbon recovery, hydraulic fracturing, and subsurface waste storage. These applications involves solid-fluid interactions, which govern the changes in the porosity which in turn affect the permeability and stiffness of the medium. Injecting fluid into the geomaterials results in permeation which exhibits small or negligible deformation of the soil skeleton followed by cavity expansion/ fingering/ fracturing (different forms of instabilities) due to the large deformation especially when the flow rate is greater than the ability of the medium to permeate the fluid. The complexity of this problem increases as the geomaterial behaves like a solid and fluid under certain conditions. Thus it is important to understand this multiphysics problem where in addition to the permeation, the elastic-plastic deformation of the soil skeleton plays a vital role during fluid injection. The phenomenon of permeation and cavity expansion in porous medium has been studied independently through extensive experimental and analytical/ numerical models. The analytical models generally use Darcy's/ diffusion equations to capture the fluid flow during permeation while elastic-plastic (Mohr-Coulomb and Modified Cam-Clay) models were used to predict the solid deformations. Hitherto, the research generally focused on modelling cavity expansion without considering the effect of injected fluid coming into the medium. Very few studies have considered the effect of injected fluid on the deformation of soil skeleton. However, the porosity changes during the fluid injection and coupled elastic-plastic deformation are not clearly understood. In this study, the phenomenon of permeation and instabilities such as cavity and finger/ fracture formation will be quantified extensively by performing experiments using a novel experimental setup in addition to utilizing image processing techniques. This experimental study will describe the fluid flow and soil deformation characteristics under different boundary conditions. Further, a well refined coupled semi-analytical model will be developed to capture the physics involved in quantifying the deformation behaviour of geomaterial during fluid injection.

Keywords: solid-fluid interaction, permeation, poroelasticity, plasticity, continuum model

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Authors: George N. Prodromidis, Frank A. Coutelieris

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Biogas can be currently considered as an alternative option for electricity production, mainly due to its high energy content (hydrocarbon-rich source), its renewable status and its relatively low utilization cost. Solid Oxide Fuel Cell (SOFC) stacks convert fuel’s chemical energy to electricity with high efficiencies and reveal significant advantages on fuel flexibility combined with lower emissions rate, especially when utilize biogas. Electricity production by biogas constitutes a composite problem which incorporates an extensive parametric analysis on numerous dynamic variables. The main scope of the presented study is to propose a detailed thermodynamic model on the optimization of SOFC-based power plants’ operation based on fundamental thermodynamics, energy and exergy balances. This model named THERMAS (THERmodynamic MAthematical Simulation model) incorporates each individual process, during electricity production, mathematically simulated for different case studies that represent real life operational conditions. Also, THERMAS offers the opportunity to choose a great variety of different values for each operational parameter individually, thus allowing for studies within unexplored and experimentally impossible operational ranges. Finally, THERMAS innovatively incorporates a specific criterion concluded by the extensive energy analysis to identify the most optimal scenario per simulated system in exergy terms. Therefore, several dynamical parameters as well as several biogas mixture compositions have been taken into account, to cover all the possible incidents. Towards the optimization process in terms of an innovative OPF (OPtimization Factor), presented here, this research study reveals that systems supplied by low methane fuels can be comparable to these supplied by pure methane. To conclude, such an innovative simulation model indicates a perspective on the optimal design of a SOFC stack based system, in the direction of the commercialization of systems utilizing biogas.

Keywords: biogas, exergy, efficiency, optimization

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Authors: Megh Patel, Arjun Chauhan, Jay Thakkar

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Hydrofracturing is the most prominent but at the same time expensive, highly skilled and time consuming well stimulation technique. Due to high cost and skilled labor involved, it is generally carried out as the consummate solution among other well stimulation techniques. Considering today’s global petroleum market, no gaffe or complications could be entertained during fracturing, as it would further hamper the current dwindling economy. The literature would be dealing with the challenges encountered during fracturing low temperature waxy reservoirs and the prominent solutions to overcome such teething troubles. During fracturing treatment for, shallow and high freezing point waxy oil reservoirs, the first line problems are to overcome uncompleted breakdown, uncompleted cleanup of fracturing fluids and cold damages to the formations by injecting cold fluid (fluid at ambient conditions). Injecting fracturing fluids at ambient conditions have the tendency to decrease the near wellbore reservoir temperature below the freezing point of oil reservoir and hence leading to wax deposition around the wellbore thereby hampering the fluid production as well as fracture propagation. To overcome such problems, solutions such as hot fracturing fluid injection, encapsulated heat generating hydraulic fracturing fluid system, and injection of wax inhibitor techniques would be discussed. The paper would also be throwing light on changes in rheological properties occurred during heating fracturing fluids and solutions to deal with it taking economic considerations into account.

Keywords: hydrofracturing, waxy reservoirs, low temperature, viscosity, crosslinkers

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Authors: Aadila Cayenne, Hinrich Uellendahl

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Optimization of the anaerobic digestion (AD) process of halophytic plants is essential as the biomass contains a high salt content that can inhibit the AD process. Anaerobic co-digestion, together with manure, can resolve the inhibitory effects of saline biomass in order to dilute the salt concentration and establish favorable conditions for the microbial consortia of the AD process. The present laboratory study investigated the co-digestion of S. ramosissima (Sram), and pig manure (PM) in batch and semi-continuous stirred tank reactors (CSTR) under mesophilic (38oC) conditions. The 0.5L batch reactor experiments were in mono- and co-digestion of Sram: PM using different percent volatile solid (VS) based ratios (0:100, 15:85, 25:75, 35:65, 50:50, 100:0) with an inoculum to substate (I/R) ratio of 2. Two 5L CSTR systems (R1 and R2) were operated for 133 days with a feed of PM in a control reactor (R1) and with a co-digestion feed in an increasing Sram VS ratio of Sram: PM of 15:85, 25:75, 35:65 in reactor R2 at an organic loading rate (OLR) of 2 gVS/L/d and hydraulic retention time (HRT) of 20 days. After a start-up phase of 8 weeks for both reactors R1 and R2 with PM feed alone, the halophyte biomass Sram was added to the feed of R2 in an increasing ratio of 15 – 35 %VS Sram over an 11-week period. The process performance was monitored by pH, total solid (TS), VS, total nitrogen (TN), ammonium-nitrogen (NH4 – N), volatile fatty acids (VFA), and biomethane production. In the batch experiments, biomethane yields of 423, 418, 392, 365, 315, and 214 mL-CH4/gVS were achieved for mixtures of 0:100, 15:85, 25:75, 35:65, 50:50, 100:0 %VS Sram: PM, respectively. In the semi-continuous reactor processes, the average biomethane yields were 235, 387, and 365 mL-CH4/gVS for the phase of a co-digestion feed ratio in R2 of 15:85, 25:75, and 35:65 %VS Sram: PM, respectively. The methane yield of PM alone in R1 was in the corresponding phases on average 260, 388, and 446 mL-CH4/gVS. Accordingly, in the continuous AD process, the methane yield of the halophyte Sram was highest at 386 mL-CH4/gVS in the co-digestion ratio of 25:75%VS Sram: PM and significantly lower at 15:85 %VS Sram: PM (100 mL-CH4/gVS) and at 35:65 %VS Sram (214 mL-CH4/gVS). The co-digestion process showed no signs of inhibition at 2 – 4 g/L NH4 – N, 3.5 – 4.5 g/L TN, and total VFA of 0.45 – 2.6 g/L (based on Acetic, Propionic, Butyric and Valeric acid). This study demonstrates that a stable co-digestion process of S. ramosissima and pig manure can be achieved with a feed of 25%VS Sram at HRT of 20 d and OLR of 2 gVS/L/d.

Keywords: anaerobic co-digestion, biomethane production, halophytes, pig manure, salicornia ramosissima

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Authors: Nahida Sultana

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Globally, an estimated 58 million people have chronic hepatitis C virus infection, with about 1.5 million new infections occurring per year. The hepatitis C virus is a blood-borne virus, and most infections occur through exposure to blood from unsafe injection practices, unsafe health care, unscreened blood transfusion, injection drug use, and sexual practices that lead to exposure to blood. Hepatitis C virus (HCV) causes chronic infections that mainly affect the liver leading to liver diseases. This study aimed to determine whether there is any significant association between HCV transmission risk factors in relation to genotypes in HCV-infected Bangladeshi patients. After quantification of HCV viral load, 36 samples were randomly selected for HCV genotyping and risk factor measurement. A greater proportion of genotype 1 (p > 0.05) patients (40%) underwent blood transfusion compared to patients (22.6%) with genotype 3 infections. More genotype 1 patient underwent surgery and invasive procedures (20%), and rather than those with genotype 3 patients (16.1%). The history of IDUs (25.8%) and sexual exposure (3.2%) are only prevalent in genotype 3 patients and absent in patients with genotype 1 (p >0.05). There was no significant statistical difference found in HCV transmission risk factors (blood transfusion, IDUs, Surgery& interventions, sexual transmission) between patients infected with genotypes 1 and 3. In HCV infection, genotype may have no relation to transmission risk factors among Bangladeshi patients.

Keywords: HCV genotype, alanine aminotransferase (ALT), HCV viral load, IDUs

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Authors: Arghavan Kazemi, Hossein Radipour

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Microsilica (silica foam) is a byproduct of ferrosilicon production and silicon metal. Microsilica particles have a spherical shape, an average diameter of 0.15 µm, and a specific surface area of 15-25 m². g-¹. The overall density of this material is 150-700 kg.m-³. Many researchers have investigated the effect of adding microsilica on the flow properties of cement mixtures. This paper investigated the effect of adding microsilica on the flow behavior and injectability of silica-based paste. For this purpose, different percentages of microsilica have been used to prepare the paste. The rheometric test was performed on all the samples with different percentages of microsilica additives using an MCR300 rotary viscometer at a temperature of 70°C. In addition, the ability to inject pastes containing different amounts of microsilica at pressures of 25, 40, 50, and (bar) 60 at constant temperature and flow in a mold with dimensions of 80 × 80 × 0.5 mm³ has been investigated. Then, the effect of microsilica addition on the strength, porosity percentage, and leachability of the sintered core was studied. The results show that the rheological behavior of the paste is pseudoplastic; also, the silane index decreases with the increase in the percentage of microsilica addition, and the viscosity increases. On the other hand, the addition of microsilica has led to the appearance of thixotropic in the paste. By increasing the amount of microsilica, the injectability has significantly improved at low pressures. The strength of the sintered core increases with the increase of microsilica and the amount of remaining porosity and leachability decreases.

Keywords: microsilica, rheological behavior, injectability, injection molding, silica-based ceramic cores, leachability

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Authors: Santosh Sharma Parajuli, Diwas Manandhar

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Background: Perioperative pain management plays an integral part in patients undergoing cardiac surgery. We studied the effect of Erector Spinae Plane block on acute postoperative pain reduction and 24 hours opioid consumption in adult cardiac surgical patients. Methods: Twenty-five adult cardiac surgical patients who underwent cardiac surgery with sternotomy in whom ESP catheters were placed preoperatively were kept in group E, and the other 25 patients who had undergone cardiac surgery without ESP catheter and pain management done with conventional opioid injection were placed in group C. Fentanyl was used for pain management. The primary study endpoint was to compare the consumption of fentanyl and to assess the numeric rating scale in the postoperative period in the first 24 hours in both groups. Results: The 24 hours fentanyl consumption was 43.00±51.29 micrograms in the Erector Spinae Plane catheter group and 147.00±60.94 micrograms in the control group postoperatively which was statistically significant (p <0.001). The numeric rating scale was also significantly reduced in the Erector Spinae Plane group compared to the control group in the first 24 hours postoperatively. Conclusion: Erector Spinae Plane block is superior to the conventional opioid injection method for postoperative pain management in CABG patients. Erector Spinae Plane block not only decreases the overall opioid consumption but also the NRS score in these patients.

Keywords: erector, spinae, plane, numerical rating scale

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Authors: Kun Hua O., Dong Woon Kim, Won Hyung Lee

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Introduction: Neuropathic pain induced by spinal or peripheral nerve injury is highly resistant to common painkillers, nerve blocks, and other pain management approaches. Recently, several new therapeutic drug candidates have been developed to control neuropathic pain. In this study, we used the spinal nerve L5 ligation (SNL) model to investigate the ability of intrathecal or intravenous Evans blue to decrease pain behavior and to study the relationship between Evans blue and the neural structure of pain transmission. Method: Neuropathic pain (allodynia) of the left hind paw was induced by unilateral SNL in Sprague-Dawley rats(n=10) in each group. Evans blue (5, 15, 50μg/10μl) or phosphate buffer saline(PBS,10μl) was injected intrathecally at 3days post-ligation or intravenously(1mg/200 μl) 3days and 5days post-ligation . Mechanical sensitivity was assessed using Von Frey filaments at 3 days post-ligation and at 2 hours, days 1, 2, 3, 5,7 after intrathecal Evans blue injection, and on days 2, 4, 7, and 11 at 14 days after intravenous injection. In the intrathecal group, microglia and glutaminergic neurons in the dorsal horn and VNUT(vesicular nucleotide transporter) in the dorsal root ganglia were tested to evaluate co-staining with Evans blue. The experimental procedures were performed in accordance with the animal care guideline of the Korean Academy of Medical Science(Animal ethic committee of Chungnam National University Hospital: CNUH-014-A0005-1). Results: Tight ligation of the L5 spinal nerve induced allodynia in the left hind paw 3 days post-ligation. Intrathecal Evans blue most significantly(P＜0.001) alleviated allodynia at 2 days after intrathecal, but not an intravenous injection. Glutaminergic neurons in the dorsal horn and VNUT in the dorsal root ganglia were co-stained with Evans blue. On the other hand, microglia in the dorsal horn were partially co-stained with Evans blue. Conclusion: We confirmed that Evans blue might have an analgesic effect through the central nervous system, not another system in neuropathic pain of the SNL animal model. These results suggest Evans blue may be a potential new drug for the treatment of chronic pain. This research was supported by the National Research Foundation of Korea (NRF-2020R1A2C100757512), funded by the Ministry of Education.

Keywords: neuropathic pain, Evas blue, intrathecal, intravenous

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Authors: Abraham Dayan

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Remediation of soil containing volatile contaminants is often conducted by vapor extraction (SVE) technique. The operation is based on injection of air at ambient temperatures with or without thermal soil warming. Thermal enhancements of soil vapor extraction (TESVE) processes are usually conducted by soil heating, sometimes assisted by added steam injections. The current study addresses a technique which has not received adequate attention and is based on using exclusively hot air as an alternative to the common TESVE practices. To demonstrate the merit of the hot air TESVE technique, a sandy soil containing contaminated water is studied. Numerical and analytical tools were used to evaluate the rate of decontamination processes for various geometries and operating conditions. The governing equations are based on the Darcy law and are applied to an expanding compressible flow within a sandy soil. The equations were solved to determine the minimal time required for complete soil remediation. An approximate closed form solution was developed based on the assumption of local thermodynamic equilibrium and on a linearized representation of temperature dependence of the vapor to air density ratio. The solution is general in nature and offers insight into the governing processes of the soil remediation operation, where self-similar temperature profiles under certain conditions may exist, and the noticeable role of the contaminants evaporation and recondensation processes in affecting the remediation time. Based on analyses of the hot air TESVE technique, it is shown that it is sufficient to heat the air during a certain period of the decontamination process without compromising its full advantage, and thereby, entailing a minimization of the air-heating-energy requirements. This in effect is achieved by regeneration, leaving the energy stored in the soil during the early period of the remediation process to heat the subsequently injected ambient air, which infiltrates through it for the decontamination of the remaining untreated soil zone. The characteristic time required to complete SVE operations are calculated as a function of, both, the injected air temperature and humidity. For a specific set of conditions, it is demonstrated that elevating the injected air temperature by 20oC, the hot air injection technique reduces the soil remediation time by 50%, while requiring 30% of additional energy consumption. Those evaluations clearly unveil the advantage of the hot air SVE process, which for insignificant cost of added air heating energy, the substantial cost expenditures for manpower and equipment utilization are reduced.

Keywords: Porous Media, Soil Decontamination, Hot Air, Vapor Extraction

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Authors: M. Javahar, H. B. Dong

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Single crystal components manufactured using Ni-base Superalloys are routinely used in the hot sections of aero engines and industrial gas turbines due to their outstanding high temperature strength, toughness and resistance to degradation in corrosive and oxidative environments. To control the quality of the single crystal turbine blades, particular attention has been paid to grain selection, which is used to obtain the single crystal morphology from a plethora of columnar grains. For this purpose, different designs of grain selectors are employed and the most common type is the spiral grain selector. A typical spiral grain selector includes a starter block and a spiral (helix) located above. It has been found that the grains with orientation well aligned to the thermal gradient survive in the starter block by competitive grain growth while the selection of the single crystal grain occurs in the spiral part. In the present study, 2D spiral selectors with different geometries were designed and produced using a state-of-the-art Bridgeman Directional Solidification casting furnace to investigate the competitive growth during grain selection in 2d grain selectors. The principal advantage of using a 2-D selector is to facilitate the wax injection process in investment casting by enabling significant degree of automation. The automation within the process can be derived by producing 2D grain selector wax patterns parts using a split die (metal mold model) coupled with wax injection stage. This will not only produce the part with high accuracy but also at an acceptable production rate.

Keywords: grain selector, single crystal, directional solidification, CMSX-4 superalloys, investment casting

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Authors: Luay Alsalmi

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Background: Facial filler is the most common type of cosmetic surgery next to botox. Permanent filler is preferred nowadays due to the low cost brought about by non-recurring injection appointments. However, such fillers pose a higher risk for complications, with even greater adverse effects when the procedure is done using unknown dermal filler injections. AIM: This study aimed to establish an algorithm to categorize and manage patients that receive permanent fillers. Materials and Methods: Twelve participants were presented to the service through emergency or as outpatient from November 2015 to May 2021. Demographics such as age, sex, date of injection, time of onset, and types of complications were collected. After examination, all cases were managed based on an algorithm established. FACE-Q was used to measure overall satisfaction and psychological well-being. Results: The algorithm to diagnose and manage these patients effectively with a high satisfaction rate was established in this study. All participants were non-smoker females with no known medical comorbidities. The algorithm presented determined the treatment plan when faced with complications. Results revealed high appearance-related psychosocial distress was observed prior to surgery, while it significantly dropped after surgery. FACE-Q was able to establish evidence of satisfactory ratings among patients prior to and after surgery. Conclusion: This treatment algorithm can guide the surgeon in formulating a suitable plan with fewer complications and a high satisfaction rate.

Keywords: facial filler, FACE-Q, psycho-social stress, botox, treatment algorithm

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Authors: Fariha Qureshi, Mohammad Tahir

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Epidemiological evidences indicated that arsenic contamination in drinking water increased the incidence of spontaneous abortion, stillbirth and premature babies in pregnant women. This study was designed to investigate the protective role of vitamin C&E against sodium arsenate induced fetal toxicity in albino mice. Twenty-four pregnant albino mice of BALB/c strain were randomly divided into 4 groups having 6 animals in each. Group A1 served as control and was injected with 0.1ml/kg/day distilled water I/P for 18 days. Groups A2,A3 & A4 received single I/P injection of sodium arsenate 35mg/kg on 8th gestational day, whereas groups A3 and A4 were also given Vitamin C and E by I/P injection, 9 mg/kg/day and 15 mg/kg/day respectively, starting from 8th GD and continued for the rest of the pregnancy period. The early implantation sites, fetal resorptions, weight of live fetuses and crown rump length were recorded. Gross morphological examination was carried out for malformations. Fetal kidneys were extracted for histological and micrometric analysis. Group A2 exhibited an increased incidence of abortion, fetal resorptions, significant decrease in number of litter and fetal weight; the difference of means was statistically significant among the groups (p<0.000). In group A2 fetal kidneys presented glomerulonephritis with acute tubular necrotic changes and interstitial fibrosis. Groups A3&A4 showed statistically significant improvement in these parameters. The results revealed the antioxidant potential of Vitamin C and E in protecting against arsenic induced fetal toxicity in mice.

Keywords: fetal toxicity, fetal resorptions, interstitial fibrosis, tocopherol

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Authors: Zunaira Zaman, David Bohannon

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This study explores the application of machine learning (ML) for detecting security vulnerabilities in source code. The research aims to assist organizations with large application portfolios and limited security testing capabilities in prioritizing security activities. ML-based approaches offer benefits such as increased confidence scores, false positives and negatives tuning, and automated feedback. The initial approach using natural language processing techniques to extract features achieved 86% accuracy during the training phase but suffered from overfitting and performed poorly on unseen datasets during testing. To address these issues, the study proposes using the abstract syntax tree (AST) for Java and C++ codebases to capture code semantics and structure and generate path-context representations for each function. The Code2Vec model architecture is used to learn distributed representations of source code snippets for training a machine-learning classifier for vulnerability prediction. The study evaluates the performance of the proposed methodology using two datasets and compares the results with existing approaches. The Devign dataset yielded 60% accuracy in predicting vulnerable code snippets and helped resist overfitting, while the Juliet Test Suite predicted specific vulnerabilities such as OS-Command Injection, Cryptographic, and Cross-Site Scripting vulnerabilities. The Code2Vec model achieved 75% accuracy and a 98% recall rate in predicting OS-Command Injection vulnerabilities. The study concludes that even partial AST representations of source code can be useful for vulnerability prediction. The approach has the potential for automated intelligent analysis of source code, including vulnerability prediction on unseen source code. State-of-the-art models using natural language processing techniques and CNN models with ensemble modelling techniques did not generalize well on unseen data and faced overfitting issues. However, predicting vulnerabilities in source code using machine learning poses challenges such as high dimensionality and complexity of source code, imbalanced datasets, and identifying specific types of vulnerabilities. Future work will address these challenges and expand the scope of the research.

Keywords: code embeddings, neural networks, natural language processing, OS command injection, software security, code properties

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Authors: Umar Hayatu Sidik

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Application of liquid base petroleum fuel (petrol and diesel) for transportation fuel causes emissions of greenhouse gases (GHGs), while natural gas (NG) reduces the emissions of greenhouse gases (GHGs). At present, compression and liquefaction are the most matured technology used for transportation system. For transportation use, compression requires high pressure (200–300 bar) while liquefaction is impractical. A relatively low pressure of 30-40 bar is achievable by adsorbed natural gas (ANG) to store nearly compressed natural gas (CNG). In this study, adsorbents for high-pressure adsorption of methane (CH4) was prepared from coconut shells and polyetheretherketone (PEEK) using potassium hydroxide (KOH) and microwave-assisted activation. Design expert software version 7.1.6 was used for optimization and prediction of preparation conditions of the adsorbents for CH₄ adsorption. Effects of microwave power, activation time and quantity of PEEK on the adsorbents performance toward CH₄ adsorption was investigated. The adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric (TG) and derivative thermogravimetric (DTG) and scanning electron microscopy (SEM). The ideal CH4 adsorption capacities of adsorbents were determined using volumetric method at pressures of 5, 17, and 35 bar at an ambient temperature and 5 oC respectively. Isotherm and kinetics models were used to validate the experimental results. The optimum preparation conditions were found to be 15 wt% amount of PEEK, 3 minutes activation time and 300 W microwave power. The highest CH4 uptake of 9.7045 mmol CH4 adsorbed/g adsorbent was recorded by M33P15 (300 W of microwave power, 3 min activation time and 15 wt% amount of PEEK) among the sorbents at an ambient temperature and 35 bar. The CH4 equilibrium data is well correlated with Sips, Toth, Freundlich and Langmuir. Isotherms revealed that the Sips isotherm has the best fit, while the kinetics studies revealed that the pseudo-second-order kinetic model best describes the adsorption process. In all scenarios studied, a decrease in temperature led to an increase in adsorption of both gases. The adsorbent (M33P15) maintained its stability even after seven adsorption/desorption cycles. The findings revealed the potential of coconut shell-PEEK as CH₄ adsorbents.

Keywords: adsorption, desorption, activated carbon, coconut shells, polyetheretherketone

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Authors: Mehrnoosh Azimi Sanavi, Hamed Ghazvini, Mehryar Zargari, Hossein Ghalehnoei, Zahra Hosseini-khah

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Objectives: Calcium Voltage-Gated Channel Subunit Alpha1 C (CACNA1C) is one of the most important genes associated with schizophrenia. Methods: 45 male Wistar rats were divided into 5 groups: saline, control, ketamine, clozapine, and risperidone. Animals in ketamine, risperidone, and clozapine groups received ketamine (30 mg/ kg-i.p.) for 10 days. After the last injection of ketamine, we started injecting clozapine (7.5 mg/kg-i.p.) risperidone (1 mg/kg-i.p.) for up to 28 days. Twenty-four hours after the last injection, open field, social interaction, and elevated plus-maze tests, and gene expression in the hippocampus were performed. Results: The results of the social interaction test revealed a significant decrease in cumulative time with ketamine compared with the saline group and an increase with clozapine and risperidone compared with the ketamine group. Moreover, results from the elevated plus-maze test demonstrated a critical decrease in open-arm time and an increase in close-arm time with ketamine compared with saline, as well as an increase in open-arm time with risperidone compared with ketamine. Further results revealed a significant increase in rearing and grooming with ketamine compared to saline, as well as a decrease with risperidone and clozapine compared to ketamine. There were no significant differences in CACNA1C gene expression between groups in the rat hippocampus. In brief, the results of this study indicated that clozapine and risperidone could partially improve cognitive impairments in the rat. However, our findings demonstrated that this treatment is not related to CACNA1C gene expression.

Keywords: schizophrenia, ketamine, clozapine, risperidone

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Authors: Abdelkader H. El Debani, Huda Gargoum, Awad G. Abdellatif

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The aim of this study is to investigate analgesic and the anti-inflammatory effects Camel Thorn Extract (CTE) in rodents. Male albino mice weighing 20-25 gm. were divided into different groups each of 8 mice. The control was given normal saline i. p., the first group was given normal saline i. p. the 2nd, 3rd, 4th, groups received different doses of CTE (330, 660, and 1300 mg/kg) respectively and the 6th group received 5mg/kg of morphine i. p. All groups (except the control group) were given acetic acid 40 min after receiving the different treatment. The number of writhes was recorded 5 min after acetic acid injection for 15 min and the % of inhibition of writhing were calculated. Different groups of rats weighing 180- 220 gm., were divided into three groups each of 5 rats. At the beginning, the volumes of the right and left paw in animals were measured by using of the plethysmometer. The 1st group was given 660 mg /kg i. p. of CTE, the 2nd group received indomethacin (5 mg/kg i. p.). One hour later, edema was induced by sub planter injection of 0.1 ml of 1 % freshly prepared suspension of carrageenan into the right hind paws of the rats. The volume of the injected paws and contra-lateral paws were measured at 0, 0.5, 1, 2, 3, 4, and 5 hours using plethysmometer. The volume of the left paw of the rat was subtracted from the volume of the right paw of the same animal. Our results showed that 330,660 and 1300 mg/kg produced 14, 49 and 84%of inhibition of writhes, indicating that CTE has a strong analgesic activity. Our data also showed that the % of inhibition of edema at 30, 60, 120, 180, and 240 min was 14,51,71,61, and 56% in the animals given camel thorn extract whereas these figures in animals given endomethacin were 14, 24, 54, 52, and 54%. These results indicate that camel thorn has anti-inflammatory activities. The mechanism of analgesic and anti-inflammatory activities needs further investigations.

Keywords: camel thorn, imdomethacin, morphine, pharmaceutical medicine

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Authors: Mia I. Allen, Bernard N. Johnson, Gagan Deep, Yixin Su, Sangeeta Singth, Ashish Kumar, , Michael A. Nader

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With no FDA-approved treatments for cocaine use disorders (CUD), research has focused on the behavioral and neuropharmacological effects of cocaine in animal models, with the goal of identifying novel interventions. While the majority of people with CUD also use tobacco/nicotine, the majority of preclinical cocaine research does not include the co-use of nicotine. The present study examined nicotine and cocaine co-use under several conditions of intravenous drug self-administration in monkeys. In Experiment 1, male rhesus monkeys (N=3) self-administered cocaine (0.001-0.1 mg/kg/injection) alone and cocaine+nicotine (0.01-0.03 mg/kg/injection) under a progressive-ratio schedule of reinforcement. When nicotine was added to cocaine, there was a significant leftward shift and significant increase in peak break point. In Experiment 2, socially housed female and male cynomolgus monkeys (N=14) self-administered cocaine under a concurrent drug-vs-food choice schedule. Combining nicotine significantly decreased cocaine choice ED50 values (i.e., shifted the cocaine dose-response curve to the left) in females but not in males. There was no evidence of social rank differences. In delay discounting studies, the co-use of nicotine and cocaine required significantly larger delays to the preferred drug reinforcer to reallocate choice compared with cocaine alone. Overall, these results suggest drug interactions of nicotine and cocaine co-use is not simply a function of potency but rather a fundamentally distinctive condition that should be utilized to better understand the neuropharmacology of CUD and the evaluation of potential treatments.

Keywords: polydrug use, animal models, nonhuman primates, behavioral pharmacology, drug self-administration

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Authors: Gabriel Malgaresi, Sara Borazjani, Hadi Madani, Pavel Bedrikovetsky

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Suspension-Colloidal flow in porous media occurs in numerous engineering fields, such as industrial water treatment, the disposal of industrial wastes into aquifers with the propagation of contaminants and low salinity water injection into petroleum reservoirs. The main effects are particle mobilization and captured by the porous rock, which can cause pore plugging and permeability reduction which is known as formation damage. Various factors such as fluid salinity, pH, temperature, and rock properties affect particle detachment. Formation damage is unfavorable specifically near injection and production wells. One way to control formation damage is pre-treatment of the rock with nanoparticles. Adsorption of nanoparticles on fines and rock surfaces alters zeta-potential of the surfaces and enhances the attachment force between the rock and fine particles. The main objective of this study is to develop a two-stage mathematical model for (1) flow and adsorption of nanoparticles on the rock in the pre-treatment stage and (2) fines migration and permeability reduction during the water production after the pre-treatment. The model accounts for adsorption and desorption of nanoparticles, fines migration, and kinetics of particle capture. The system of equations allows for the exact solution. The non-self-similar wave-interaction problem was solved by the Method of Characteristics. The analytical model is new in two ways: First, it accounts for the specific boundary and initial condition describing the injection of nanoparticle and production from the pre-treated porous media; second, it contains the effect of nanoparticle sorption hysteresis. The derived analytical model contains explicit formulae for the concentration fronts along with pressure drop. The solution is used to determine the optimal injection concentration of nanoparticle to avoid formation damage. The mathematical model was validated via an innovative laboratory program. The laboratory study includes two sets of core-flood experiments: (1) production of water without nanoparticle pre-treatment; (2) pre-treatment of a similar core with nanoparticles followed by water production. Positively-charged Alumina nanoparticles with the average particle size of 100 nm were used for the rock pre-treatment. The core was saturated with the nanoparticles and then flushed with low salinity water; pressure drop across the core and the outlet fine concentration was monitored and used for model validation. The results of the analytical modeling showed a significant reduction in the fine outlet concentration and formation damage. This observation was in great agreement with the results of core-flood data. The exact solution accurately describes fines particle breakthroughs and evaluates the positive effect of nanoparticles in formation damage. We show that the adsorbed concentration of nanoparticle highly affects the permeability of the porous media. For the laboratory case presented, the reduction of permeability after 1 PVI production in the pre-treated scenario is 50% lower than the reference case. The main outcome of this study is to provide a validated mathematical model to evaluate the effect of nanoparticles on formation damage.

Keywords: nano-particles, formation damage, permeability, fines migration

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Authors: Aparna Datta, Mahabub Alam

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Animal welfare is comparatively new area of research in Bangladesh and welfare concern for animal is increasing day by day. The study was conducted to investigate the animal welfare violations during treatment at different level of hospitals in Bangladesh and India. This study was conducted between January and May, 2017. The recorded data (N=180) were categorized into eight major types of violation like - delay in starting treatment, non-specific treatment, surgery without anesthesia, use of unsterilized needle, rough and painful handling, fearful approach, multiple pricking during injection and use of blunt needle. Categorized groups were analyzed according to different hospitals like Upazila Veterinary Hospitals, Bangladesh (UVHs), SAQ-Teaching Veterinary Hospital, Bangladesh (SAQTVH) and Veterinary College and Research Institute, India (VCRI). Among all hospitals, violation during treatment more frequently occurred in UVH. Among all violations, surgery without anesthesia was only found in UVH (80%) and it was belong to considerable number of cases (80%). In the view of other major violations like - non-specific treatment was 69% in UVHs, 13% in SAQTVH and 5% in VCRI. Use of unsterilized instruments during treatment was also higher in UVHs (65%) than SAQTVH (5%) and VCRI (1%). But delay in starting treatment varied insignificantly and it was 26-42% across the different levels of hospitals. Although multiple pricking during injection was found 30% cases in UVH, but statistical variations with other level of hospitals were unnoticed (p>0.05). The findings of this study will help to take necessary steps to control violation against animal welfare during treatment. A comprehensive study considering all levels of hospitals including field treatment is also recommended to find out the welfare violations during treatment.

Keywords: animal welfare, treatment, veterinary hospitals, violations

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Authors: Ayman M. M. Abdelhaleem, Mustafa Gamal Sadek, Kamal Reyad, Montasser M. Dewidar

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The main objective of this research is to study the effect of adding polycarbonate (PC) to pure Acrylonitrile Butadiene Styrene (ABS) using the injection moulding process. The PC was mixed mechanically with ABS in 10%, 20%, 30%, 40%, and 50% by weight. The mechanical properties of pure ABS reinforced with PC were investigated using tensile, impact, hardness, and wear tests. The results showed that, by adding 10%, 20%, 30%, 40%, and 50% wt. of PC to the pure ABS, the ultimate tensile strength increased from 55 N/mm2 for neat ABS to 57 N/mm2 (i.e. 3.63%), 60 N/mm2 (i.e. 9.09%), 63 N/mm2 (i.e. 14.54%), 66 N/mm2 (i.e. 20%), 69 N/mm2 (i.e. 25.45%) respectively. Test results also revealed nearly 5.72% improvement in young's modulus by adding 10% of PC to ABS, 16.74% improvement by adding 20%, 23.34% improvement by adding 30%, 27.75% improvement by adding 40%, and no other increase in case of 50%. The impact test results showed that with the increase of the PC content, first, the impact strength decreased and then increased gradually. The impact strength decreased rapidly when the content of PC was 0% to 10% range. As well as, in the case of 20%, 30%, 40%, and 50% PC, the impact strength is increased. The hardness test results, using the Shore D tester, showed that, as the PC particles contents increased, the hardness increased from 76 for the ABS to 80 for 10% PC, and decreased to 79 for 20% PC, and then increased to 80 in case of 30%, 40%, and 50% PC. Wear test results showed that PC improves the wear resistance of ABS/PC blends. Positron annihilation lifetime spectroscopy showed that with an increase of PC in ABS/PC blends, a slight decrease in free volume size and an increase in the tensile strength due to good adhesion between PC and ABS matrix, which acted as an advantage in the polymer matrix.

Keywords: ABS, PC, injection molding process, mechanical properties, lifetime spectroscopy

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Authors: K. Rajarajeswaran, Krishna Prasad

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Introduction: Refractory shock is a typical consequence of sepsis that does not improve with standard vasopressor therapy. A possible adjuvant therapeutic option for treating refractory shock in sepsis is methylene blue. This study looked at the effects of intravenous methylene blue plus norepinephrine given as a single bolus infusion on mortality and hemodynamic improvement in patients suffering from refractory shock. Methodology: This six-month observational prospective study was carried out at an intensive care unit, teaching hospital, and medical college. It involved 112 patients who had been diagnosed with refractory septic shock and needed vasopressor medication. Group B received injection norepinephrine 0.01 µg/kg/min infusion alone, while Group A received injection methylene blue 2 mg/kg iv single bolus (fixed dose) in addition to injection norepinephrine 0.01 µg/kg/min infusion. Both groups' noradrenaline doses were titrated to reach the desired MAP of 60–75 mm Hg. The amount of norepinephrine needed to sustain a MAP of more than 60 mm Hg was the data gathered. Serum lactate, procalcitonin level, C-reactive protein, length of stay in the intensive care unit (ICU), sequential organ failure assessment (SOFA) score, and duration of mechanical ventilation, incidence of acute kidney injury (AKI), and mortality were compared. Results: A total of 112 patients with refractory shock were included in the study. With the use of IV methylene blue, 36 (59.3%) patients showed significant improvement in MAP within 2 hours (77.12 ± 8.90 vs 74.28 ± 21.84, p = 0.005). Responders were 4.009 times more likely to have vasopressor-free time within 24 hours (19.5% vs 6.1%, p = 0.022, odds ratio 5.017, 95% confidence interval, 1.110–14.283). The serum lactate was lower, and urine output was higher in group I than in group II (p <0.05). Group I had a significantly greater reduction in SOFA score in 12 hours than group II. However, there was no significant difference in terms of mortality, length of ICU stay, ventilator free days, and incidence of AKI. In the responder group, there was a significant increase in the MAP and decrease in vasopressor requirement pre- and post-infusion of methylene blue (p < 0.05). Responder had shorter vasopressor-free days as compared with non-responder (5.44 vs 6.99, p = 0.007). Conclusion: When administered as adjuvant therapy, a single-dose bolus infusion of Methylene Blue plus Norepinephrine may aid in meeting early resuscitation goals for the management of patients with septic shock. But the patients' death rate, ICU stay duration, ventilator-free days, or incidence of AKI were unchanged.

Keywords: norepinephrine, methylene blue, shock, vasopressor

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Authors: Ruth Diego, Luis M. Romeo, Antonio Morán

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In the present work, a study of the coupling of a Bioelectrochemical System together with an oxy-combustion boiler is carried out; specifically, it proposes to connect the combustion gas outlet of a boiler with a microbial electrolysis cell (MEC) where the CO2 from the gases are transformed into methane in the cathode chamber, and the oxygen produced in the anode chamber is recirculated to the oxy-combustion boiler. The MEC mainly consists of two electrodes (anode and cathode) immersed in an aqueous electrolyte; these electrodes are separated by a proton exchange membrane (PEM). In this case, the anode is abiotic (where oxygen is produced), and it is at the cathode that an electroactive biofilm is formed with microorganisms that catalyze the CO2 reduction reactions. Real data from an oxy-combustion process in a boiler of around 20 thermal MW have been used for this study and are combined with data obtained on a smaller scale (laboratory-pilot scale) to determine the yields that could be obtained considering the system as environmentally sustainable energy storage. In this way, an attempt is made to integrate a relatively conventional energy production system (oxy-combustion) with a biological system (microbial electrolysis cell), which is a challenge to be addressed in this type of new hybrid scheme. In this way, a novel concept is presented with the basic dimensioning of the necessary equipment and the efficiency of the global process. In this work, it has been calculated that the efficiency of this power-to-gas system based on MEC cells when coupled to industrial processes is of the same order of magnitude as the most promising equivalent routes. The proposed process has two main limitations, the overpotentials in the electrodes that penalize the overall efficiency and the need for storage tanks for the process gases. The results of the calculations carried out in this work show that certain real potentials achieve an acceptable performance. Regarding the tanks, with adequate dimensioning, it is possible to achieve complete autonomy. The proposed system called OxyMES provides energy storage without energetically penalizing the process when compared to an oxy-combustion plant with conventional CO2 capture. According to the results obtained, this system can be applied as a measure to decarbonize an industry, changing the original fuel of the oxy-combustion boiler to the biogas generated in the MEC cell. It could also be used to neutralize CO2 emissions from industry by converting it to methane and then injecting it into the natural gas grid.

Keywords: microbial electrolysis cells, oxy-combustion, co2, power-to-gas

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Authors: Bita Mohajernia, R. J. Urbanic

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Mold making techniques have focused on meeting the customers’ functional and process requirements; however, today, molds are increasing in size and sophistication, and are difficult to manufacture, transport, and set up due to their size and mass. Presently, mold weight saving techniques focus on pockets to reduce the mass of the mold, but the overall size is still large, which introduces costs related to the stock material purchase, processing time for process planning, machining and validation, and excess waste materials. Reducing the overall size of the mold is desirable for many reasons, but the functional requirements, tool life, and durability cannot be compromised in the process. It is proposed to use Finite Element Analysis simulation tools to model the forces, and pressures to determine where the material can be removed. The potential results of this project will reduce manufacturing costs. In this study, a light weight structure is defined by an optimal distribution of material to carry external loads. The optimization objective of this research is to determine methods to provide the optimum layout for the mold structure. The topology optimization method is utilized to improve structural stiffness while decreasing the weight using the OptiStruct software. The optimized CAD model is compared with the primary geometry of the mold from the NX software. Results of optimization show an 8% weight reduction while the actual performance of the optimized structure, validated by physical testing, is similar to the original structure.

Keywords: finite element analysis, plastic injection molding, topology optimization, weight reduction

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Authors: Zahreddine Hafsi, Manoranjan Mishra , Sami Elaoud

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Ensuring the maximum recovery rate of oil from reservoir rocks is a challenging task that requires preliminary numerical analysis of different techniques used to enhance the recovery process. After conventional oil recovery processes and in order to retrieve oil left behind after the primary recovery phase, water flooding in one of several techniques used for enhanced oil recovery (EOR). In this research work, EOR via water flooding is numerically modeled, and hydrodynamic instabilities resulted from immiscible oil-water flow in reservoir rocks are investigated. An oil reservoir is a porous medium consisted of many fractures of tiny dimensions. For modeling purposes, the oil reservoir is considered as a collection of capillary tubes which provides useful insights into how fluids behave in the reservoir pore spaces. Equations governing oil-water flow in oil reservoir rocks are developed and numerically solved following a finite element scheme. Numerical results are obtained using Comsol Multiphysics software. The two phase Darcy module of COMSOL Multiphysics allows modelling the imbibition process by the injection of water (as wetting phase) into an oil reservoir. Van Genuchten, Brooks Corey and Levrett models were considered as retention models and obtained flow configurations are compared, and the governing parameters are discussed. For the considered retention models it was found that onset of instabilities viz. fingering phenomenon is highly dependent on the capillary pressure as well as the boundary conditions, i.e., the inlet pressure and the injection velocity.

Keywords: capillary pressure, EOR process, immiscible flow, numerical modelling

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Authors: Lucian Capitanu, Virgil Florescu

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Often for the laboratory studies, modeling of specific tribological processes raises special problems. One such problem is the modeling of some temperatures and extremely high contact pressures, allowing modeling of temperatures and pressures at which the injection or extrusion processing of thermoplastic materials takes place. Tribological problems occur mainly in thermoplastics materials reinforced with glass fibers. They produce an advanced wear to the barrels and screws of processing machines, in short time. Obtaining temperatures around 210 °C and higher, as well as pressures around 100 MPa is very difficult in the laboratory. This paper reports a simple and convenient solution to get these conditions, using friction sliding couples with linear contact, cylindrical liner plastic filled with glass fibers on plate steel samples, polished and super-finished. C120 steel, which is a steel for moulds and Rp3 steel, high speed steel for tools, were used. Obtaining the pressure was achieved by continuous request of the liner in rotational movement up to its elasticity limits, when the dry friction coefficient reaches or exceeds the hardness value of 0.5 HB. By dissipation of the power lost by friction on flat steel sample, are reached contact temperatures at the metal surface that reach and exceed 230 °C, being placed in the range temperature values of the injection. Contact pressures (in load and materials conditions used) ranging from 16.3-36.4 MPa were obtained depending on the plastic material used and the glass fibers content.

Keywords: plastics with glass fibers, dry friction, linear contact, contact temperature, contact pressure, experimental simulation

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Authors: Naomi Sakamoto, Eisuke Fukuma, Mika Nashimoto, Yoshitomo Koshida

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Background: Selective localization of the metastatic lymph node with clip and removal of clipped nodes with sentinel lymph node (SLN), known as targeted axillary dissection (TAD), reduced false-negative rates (FNR) of SLN biopsy (SLNB) after neoadjuvant chemotherapy (NAC). For the patients who achieved nodal pathologic complete response (pCR), accurate staging of axilla by TAD lead to omit axillary lymph node dissection (ALND), decreasing postoperative arm morbidity without a negative effect on overall survival. This study aimed to investigate the ultrasound (US) identification rate and success removal rate of two kinds of ultrasound-visible clips placed in metastatic lymph nodes during TAD procedure. Methods: This prospective study was conducted using patients with clinically T1-3, N1, 2, M0 breast cancer undergoing NAC followed by surgery. A US-visible clip was placed in the suspicious lymph node under US guidance before neoadjuvant chemotherapy. Before surgery, US examination was performed to evaluate the detection rate of clipped node. During the surgery, the clipped node was removed using several localization techniques, including hook-wire localization, dye-injection, or fluorescence technique, followed by a dual-technique SLNB and resection of palpable nodes if present. For the fluorescence technique, after injection of 0.1-0.2 mL of indocyanine green dye (ICG) into the clipped node, ICG fluorescent imaging was performed using the Photodynamic Eye infrared camera (Hamamatsu Photonics k. k., Shizuoka, Japan). For the dye injection method, 0.1-0.2 mL of pyoktanin blue dye was injected into the clipped node. Results: A total of 29 patients were enrolled. Hydromark™ breast biopsy site markers (Hydromark, T3 shape; Devicor Medical Japan, Tokyo, Japan) was used in 15patients, whereas a UltraCor™ Twirl™ breast marker (Twirl; C.R. Bard, Inc, NJ, USA) was placed in 14 patients. US identified the clipped node marked with the UltraCore Twirl in 100% (14/14) and with the Hydromark in 93.3% (14/15, p = ns). Success removal of clipped node marked with the UltraCore Twirl was achieved in 100% (14/14), whereas the node marked with the Hydromark was removed in 80% (12/15) (p = ns). Conclusions: The ultrasound identification rate differed between the two types of ultrasound-visible clips, which also affected the success removal rate of clipped nodes. Labelling the positive node with a US-highly-visible clip allowed successful TAD.

Keywords: breast cancer, neoadjuvant chemotherapy, targeted axillary dissection, breast tissue marker, clip

Procedia PDF Downloads 67