Search results for: fuel injection timing

Authors: A. Hegazy, Ahmed Elsayed, Essam El Shenawy, N. Allam, Hala Handal, K. R. Mahmoud

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Highly crystalline, TiO₂ pristine sub-10 nm anatase nanocrystals were fabricated at low temperatures by post hydrothermal treatment of the as-prepared TiO₂ nanoparticles. This treatment resulted in bandgap narrowing and increased photocurrent density value (3.8 mA/cm²) when this material was employed in water splitting systems. The achieved photocurrent values are among the highest reported ones so far for the fabricated nanoparticles at this low temperature. This might be explained by the increased surface defects of the prepared nanoparticles. It resulted in bandgap narrowing that was further investigated using positron annihilation experiments by measuring positron lifetime and Doppler broadening. Besides, homogeneous spherical TiO₂ nanoparticles were synthesized in large diameter and high surface area and the high percentage of (001) facet by sol-gel method using potassium persulfate (K₂S₂O₈) as an oxidizing agent. The fabricated particles exhibited high exposed surface area, high photoactivity and reduced band gap. Enhanced performance for water splitting applications was displayed by formed TiO₂ nanoparticles. Their morphological and structural properties were studied to optimize their synthesis parameters in an attempt to construct more applicable fuel cells in the industry for hydrogen fuel production.

Keywords: positron annihilation, solar energy, TiO2 nanoparticles, water splitting

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Authors: Mohamed Amine El Hameur, Lyes Tarabet, Mahfoudh Cerdoun, Boubkr Zebiri, Giovanni Ferrara

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Due to the drastic environmental and energy regulations regarding the reduction of exhaust emissions and fuel consumption, added to the increasing demand for powerful performance, several automotive manufacturers are constantly obliged to redesign their existing products and/or develop novel powertrain techniques to respond to the aforementioned restrictions. In this aspect, an implemented approach is proposed in the present work to boost a 1.5 L, three-cylinder Diesel engine with a new turbocharger, based on 1D preliminary design codes, 3D design, and numerical assessment of a suitable radial turbine followed by an accurate selection procedure of an adequate centrifugal compressor. Furthermore, to investigate the effect of the turbine’s rotor position on the simulation convergence, stability, and calculation time; two combinations (rotor blade- volute) have been assessed. Consequently, significant results are obtained when comparing the original turbocharged engine and the new one at the engine’s full load and rated speed (@4500rpm) conditions. A maximum improvement in terms of brake-specific fuel consumption, thermal efficiency, total-to-static turbine efficiency, and total-to-total compressor efficiency equal 6.5% (corresponding to a decrease of 2.3 litre/hr in fuel consumption), 7%, 10.9%, and 19.9%, respectively.

Keywords: CFD investigation, engine boosting, turbine design, turbocharger, rotor blade positioning

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Authors: Delele Worku Ayele, Bing-Joe Hwang

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A method that does not employ hot injection techniques has been developed for the size-tunable synthesis of high-quality CdSe quantum dots (QDs) with a zinc blende structure. In this environmentally benign synthetic route, which uses relatively less toxic precursors, solvents, and capping ligands, CdSe QDs that absorb visible light are obtained. The size of the as-prepared CdSe QDs and, thus, their optical properties can be manipulated by changing the microwave reaction conditions. The QDs are characterized by XRD, TEM, UV-vis, FTIR, time-resolved fluorescence spectroscopy, and fluorescence spectrophotometry. In this approach, the reaction is conducted in open air and at a much lower temperature than in hot injection techniques. The use of microwaves in this process allows for a highly reproducible and effective synthesis protocol that is fully adaptable for mass production and can be easily employed to synthesize a variety of semiconductor QDs with the desired properties. The possible application of the as-prepared CdSe QDs has been also assessed using deposition on TiO2 films.

Keywords: CdSe QDs, Na2SeSO3, microwave (MW), oleic acid, mass production, average life time

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Authors: Y. A. Shapovalov, F. M. Gumerov, M. K. Nauryzbaev, S. V. Mazanov, R. A. Usmanov, A. V. Klinov, L. K. Safiullina, S. A. Soshin

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A flow-through installation was created and manufactured for the transesterification of triglycerides of fatty acids and production of biodiesel fuel under supercritical fluid conditions. Transesterification of rapeseed oil with ethanol was carried out according to two parameters: temperature and the ratio of alcohol/oil mixture at the constant pressure of 19 MPa. The kinetics of the yield of fatty acids ethyl esters (FAEE) was determined in the temperature range of 320-380 °C at the alcohol/oil molar ratio of 6:1-20:1. The content of the formed FAEE was determined by the method of correlation of the resulting biodiesel fuel by its kinematic viscosity. The maximum FAEE yield (about 90%) was obtained within 30 min at the ethanol/oil molar ratio of 12:1 and a temperature of 380 °C. When studying of transesterification of triglycerides, a kinetic model of an isothermal flow reactor was used. The reaction order implemented in the flow reactor has been determined. The first order of the reaction was confirmed by data on the conversion of FAEE during the reaction at different temperatures and the molar ratios of the initial reagents (ethanol/oil). Using the Arrhenius equation, the values of the effective constants of the transesterification reaction rate were calculated at different reaction temperatures. In addition, based on the experimental data, the activation energy and the pre-exponential factor of the transesterification reaction were determined.

Keywords: biodiesel, fatty acid esters, supercritical fluid technology, transesterification

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Authors: Abdullah Almatouq

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Understanding the impact of key operational variables on concurrent energy generation and phosphorus recovery in microbial fuel cell is required to improve the process and reduce the operational cost. In this study, full factorial design (FFD) and central composite designs (CCD) were employed to identify the effect of influent COD concentration and cathode aeration flow rate on energy generation and phosphorus (P) recovery and to optimise MFC power density and P recovery. Results showed that influent chemical oxygen demand (COD) concentration and cathode aeration flow rate had a significant effect on power density, coulombic efficiency, phosphorus precipitation efficiency and phosphorus precipitation rate at the cathode. P precipitation was negatively affected by the generated current during the batch duration. The generated energy was reduced due to struvite being precipitated on the cathode surface, which might obstruct the mass transfer of ions and oxygen. Response surface mathematical model was used to predict the optimum operating conditions that resulted in a maximum power density and phosphorus precipitation efficiency of 184 mW/m² and 84%, and this corresponds to COD= 1700 mg/L and aeration flow rate=210 mL/min. The findings highlight the importance of the operational conditions of energy generation and phosphorus recovery.

Keywords: energy, microbial fuel cell, phosphorus, struvite

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Authors: Aliyu Mohammed Lawal, Dahiru Ya'u Gital

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The problems placed on the environment as a result of energy generation and usage in Nigeria are: Potential damage to the environment health by Co, Co2, Sox and Nox effluent gas emissions and global warming. For instance in the year 2004 in Nigeria energy consumption was 58% oil and 34% natural gas but about 94 million metric tons of Co2 was emitted out of which 64% came from fossil fuels while about 35% came from fuel wood. The findings from this research on how to alleviate these problems are that long term sustainable development solutions should be enhanced globally; energy should be used more rationally renewable energy resources should be exploited and the existing emissions should be controlled to tolerate limits because the increase in energy demand in Nigeria places enormous strain on current energy facilities.

Keywords: energy generation, environmental health, effluent gas emission, global warming, fossil fuel

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Authors: Waqas Hassan Tanveer, Yoon Ho Lee, Taehyun Park, Wonjong Yu, Yaegeun Lee, Yusung Kim, Suk Won Cha

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Nickel-Gadolinium Doped Ceria (Ni-GDC) cermet anodic thin films were prepared on Scandia Stabilized Zirconia (ScSZ) electrolyte supports by radio frequency (RF) sputtering, with a range of different sputtering powers (50 – 200W) and background Ar gas pressures (30 – 90mTorr). The effects of varying sputtering power and pressure on the properties of Ni-GDC films were studied using Focused Ion Beam (FIB), X-ray Photoelectron Spectroscopy (XPS), X-ray Diffraction (XRD), Energy Dispersive X-ray (EDX), and Atomic Force Microscopy (AFM) techniques. The Ni content was found to be always higher than the Ce content, at all sputtering conditions. This increased Ni content was attributed to significantly higher energy transfer efficiency of Ni ions as compared to Ce ions with Ar background sputtering gas. The solid oxide fuel cell configuration was completed by using lanthanum strontium manganite (LSM/YSZ) cathodes on the other side of ScSZ supports. Performance comparison of cells was done by Voltage-Current-Power (VIP) curves, while the resistances of various cell components were observed by nyquist plots. Initial results showed that anode films made by higher powered RF sputtering performed better than lower powered ones for a specific Ar pressure. Interestingly, however, anodes made at highest power and pressure, were not the ones that showed the maximum power output at an intermediate solid oxide fuel cell temperature of 800°C. Finally, an optimal sputtering condition was reported for high performance Ni-GDC anodes.

Keywords: intermediate temperature solid oxide fuel cells, nickel-cermet anodic thin films, nyquist plots, radio frequency sputtering

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Authors: Rajeev jain, D. C. Tiwari, Praveena Mishra

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Nano-composite of polypyrrole/multiwalled carbon nanotubes:mangenese oxide (PPy/MWCNT:MnO2) was electrochemically deposited on the surface of carbon cloth (CC). The nano-composite was structurally characterized by FTIR, SEM, TEM and UV-Vis studies. Nano-composite was also characterized by cyclic voltammetry (CV), current voltage measurements (I-V) and the optical band gaps of film were evaluated from UV-Vis absorption studies. The PPy/MWCNT:MnO2 nano-composite was used as anode in microbial fuel cell (MFC) for sewage waste water treatment, power and coulombic efficiency measurement. The prepared electrode showed good electrical conductivity (0.1185 S m-1). This was also supported by band gap measurements (direct 0.8 eV, indirect 1.3 eV). The obtained maximum power density was 1125.4 mW m-2, highest chemical oxygen demand (COD) removal efficiency was 93% and the maximum coulombic efficiency was 59%. For the first time PPy/MWCNT:MnO2 nano-composite for MFC prepared from nano-composite electrode having the potential for the use in MFC with good stability and better adhesion of microbes is being reported. The SEM images confirm the growth and development of microbe’s colony.

Keywords: carbon cloth, electro-polymerization, functionalization, microbial fuel cells, multi walled carbon nanotubes, polypyrrole

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Authors: Nicole Laws, William L. Roberts, Saumitra Saxena, Krishnamurthy Anand, Sreenivasa Gubba, Ziad Dawood, Aiping Chen

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Boiler-fired power plants that operate steam turbines in Saudi Arabia use vanadium-containing fuel oil. In a super- or sub-critical steam cycle, the skin temperature of boiler tube metal can reach close to 600-1000°C depending on the location of the tubes. At high temperatures, corrosion by the sodium-vanadium-oxygen-sulfur eutectic can become a significant risk. The experimental work utilized a state-of-the-art high-temperature, high-pressure burner rig at KAUST, King Abdullah University of Science and Technology. To establish corrosion rates of different boiler tubes and materials, SA 213 T12, SA 213 T22, SA 213 T91, and Inconel 600, were used under various corrosive media, including vanadium to sulfur levels and vanadium to sodium ratios. The results obtained from the experiments establish a corrosion rate map for the materials involved and layout an empirical framework to rank the life of boiler tube materials under different operating conditions. Safe windows of operation are proposed for burning liquid fuels under varying vanadium, sodium, and sulfur levels before corrosion rates become a matter of significance under high-temperature conditions

Keywords: boiler tube life, hot corrosion, steam boilers, vanadium in fuel oil

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Authors: Subhash Chander, Tejinder Kumar Jindal

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Due to its simplicity, Pulse detonation engine technology has recently emerged as a future aerospace propulsion technology. In this paper, we studied various parameters affecting the performance of Pulse detonation engine (PDE) like tube length for proper deflagration to detonation transition (DDT), tube diameter (combustion tube), tube length, Shelkin spiral, Cell size, Equivalence ratio of fuel used etc. We have discussed various techniques for reducing the length of pulse tube by using various DDT enhancing devices. The effect of length of the tube from 40 mm to 3000 mm and diameter from 10 mm to 100 mm has been analyzed. The fuel used is C2H2 and oxidizer is O2. The results are processed in MATLAB for drawing valid conclusions.

Keywords: pulse detonation engine (PDE), deflagration to detonation (DDT), Schelkin spiral, cell size (λ)

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Authors: Pawthawala Nancy Manish, Syed Alay Hashim

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A hybrid rocket is a rocket engine which uses propellants in two different states of matter- one is in solid and the other either gas or liquid. A hybrid rocket exhibit advantages over both liquid rockets and solid rockets especially in terms of simplicity, stop-start-restart capabilities, safety and cost. This paper deals the design and development of a hybrid rocket having paraffin wax as solid fuel and liquid oxygen as oxidizer. Due to variation of pressure in combustion chamber there is significantly change in mass flow rate, burning rate and uneven regression along the length of the grain. This project describes the working model of a hybrid propellant rocket motor. We have designed a hybrid rocket thrust chamber based on the predetermined combustion chamber pressure and the properties of hybrid propellant. This project is all ready in working condition with normal oxygen injector. Now we have planned to modify the injector design to improve the combustion property. We will use spray type injector for injecting the oxidizer. This idea will increase the performance followed by the regression rate of the solid fuel. By employing mass conservation law, oxygen mass flux, oxidizer/fuel ratio and regression rate the thrust coefficient can be obtained for our current design. CATIA V5 R20 is our design software for the complete setup. This project is fully based on experimental evaluation and the collection of combustion and flow parameters. The thrust chamber is made of stainless steel and the duration of test is around 15-20 seconds (Maximum). These experiments indicates that paraffin based fuel provides the opportunity to satisfy a broad range of mission requirements for the next generation of the hybrid rocket system.

Keywords: burning rate, liquid oxygen, mass flow rate, paraffin wax and sugar

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Authors: Quoc Ngoc Phan, Hieu Van Nguyen, Minh Hong Nguyen

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This study presents an integrated approach using Mercury Injection Capillary Pressure (MICP) and petrographic analysis to assess the seal quality of the inter-bedded shale formations which are considered the intra-formation top seals of hydrocarbon bearing zones in Green Dragon structure. Based on the hydrocarbon column height (HCH) at leak point derived from capillary pressure data, four seal types were identified. Furthermore, the results of scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were interpreted to clarify the influence of clay minerals on seal capacity. The result of the study indicated that the inter-bedded shale formations are the good sealing quality with a majority of analyzed samples ranked type A and B seals in the sample set. Both seal types occurred mainly in mudstones with pore radius estimated less than 0.251 µm. Overall, type A and B seals contained a large amount of authigenic clay minerals such as illite, chlorite which showed the complexity of morphological arrangement in pore space. Conversely, the least common seal type C and D were presented in moderately compacted sandstones with more open pore radius. It is noticeable that there was a reduction of illite and chlorite in clay mineral fraction of these seal type. It is expected that the integrated analysis approach using Mercury Injection Capillary Pressure and petrographic data employed in this study can be applied to assess the sealing quality of future well sites in Green Dragon or other structures.

Keywords: seal capacity, hydrocarbon height column, seal type, SEM, XRD

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Authors: Ahmed Slami, Med El Amine Brixi Nigassa, Nassima Labdelli, Sofiane Soulimane, Arnaud Pothier

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Many people suffer from diabetes, a disease marked by abnormal levels of sugar in the blood; 285 million people have diabetes, 6.6% of the world adult population (in 2010), according to the International Diabetes Federation. Insulin medicament is invented to be injected into the body. Generally, the injection requires the patient to do it manually. However, in many cases he will be unable to inject the drug, saw that among the side effects of hyperglycemia is the weakness of the whole body. The researchers designed a medical device that injects insulin too autonomously by using micro-pumps. Many micro-pumps of concepts have been investigated during the last two decades for injecting molecules in blood or in the body. However, all these micro-pumps are intended for slow infusion of drug (injection of few microliters by minute). Now, the challenge is to develop micro-pumps for fast injections (1 microliter in 10 seconds) with accuracy of the order of microliter. Recently, studies have shown that only piezoelectric actuators can achieve this performance, knowing that few systems at the microscopic level were presented. These reasons lead us to design new smart microsystems injection drugs. Therefore, many technological advances are still to achieve the improvement of materials to their uses, while going through their characterization and modeling action mechanisms themselves. Moreover, it remains to study the integration of the piezoelectric micro-pump in the microfluidic platform features to explore and evaluate the performance of these new micro devices. In this work, we propose a new micro-pump model based on piezoelectric actuation with a new design. Here, we use a finite element model with Comsol software. Our device is composed of two pumping chambers, two diaphragms and two actuators (piezoelectric disks). The latter parts will apply a mechanical force on the membrane in a periodic manner. The membrane deformation allows the fluid pumping, the suction and discharge of the liquid. In this study, we present the modeling results as function as device geometry properties, films thickness, and materials properties. Here, we demonstrate that we can achieve fast injection. The results of these simulations will provide quantitative performance of our micro-pumps. Concern the spatial actuation, fluid rate and allows optimization of the fabrication process in terms of materials and integration steps.

Keywords: COMSOL software, piezoelectric, micro-pump, microfluidic

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Authors: Despina Vamvuka, Despina Pentari

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Forestry wastes are readily available in large quantities around the world. Based on European Green Deal for the deployment of renewable and decarbonized energy by 2050, as well as global energy crisis, energy recovery from such wastes reducing greenhouse gas emissions is very attractive. Gasification has superior environmental performance to combustion, producing a clean fuel gas utilized in internal combustion engines, gas turbines, solid oxide fuel cells, or for synthesis of liquid bio-fuels and value-added chemicals. In this work, pine needles, which are abundantly found in Mediterranean countries, were gasified by either steam or carbon dioxide via a two-step process to improve reactivity and eliminate tar, employing a fixed bed unit and a thermal analysis system. Solid, liquid and gaseous products from the whole process were characterized and their energy potential was determined. Thermal behaviour, reactivity, conversion and energy recovery were examined. The gasification process took place above 650°C. At 950°C conversion and energy recovery were 77% dry and 2 under a flow of steam and 85% dry and 2.9 under a flow of carbon dioxide, respectively. Organic matter was almost completely converted to syngas, the yield of which varied between 89% and 99%. The higher heating values of biochar, bio-oil and pyrolysis gas were 27.8 MJ/kg, 33.5 MJ/kg and 13.6 MJ/m3. Upon steam or carbon dioxide gasification, the higher heating value of syngas produced was 11.5 MJ/m3 and 12.7 MJ/m3, respectively.

Keywords: gasification, biomass, steam, carbon dioxide

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Authors: Nurul Hamirah Kamsani, Mohd Hamim Rajikin, Nor Ashikin Mohamed Noor Khan, Sharaniza Abdul Rahim

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Cytoskeletal structures, in particular actin and tubulin, provide a fundamental framework in all cells, including embryos. Under influence of nicotine, the cytoskeletal organization may be subjected to oxidative stress (OS) insult and cause alteration. Tocotrienol-rich fraction (TRF) is proven to enhance fertility better than the other sub-group of Vitamin E, tocopherols (TCPs). The objective of this study was to evaluate the effects of TRF on 1) actin and tubulin of 2- and 8-cell murine embryos and 2) the regulation of reactive oxygen species (ROS)-scavenging enzymes; induced by nicotine. Twenty four female Balb/C were subjected to either subcutaneous (sc) injection of 0.9% NaCl; sc injection of 3.0 mg/kg bw/day nicotine; sc injection of 3.0 mg/kg bw/day nicotine + oral gavage (OG) of 60 mg/kg bw/day TRF; or OG of 60 mg/kg bw/day TRF for 7 consecutive days. After superovulation and mating, animals were euthanized. 2-cell developing embryos were retrieved. 50% of the retrieved embryos were visualized under confocal laser staining microscopy (CLSM) for alterations of actin and tubulin. The remaining amount of embryos was cultured in vitro until 8-cell stage followed by CLSM visualization. Blood plasma was subjected to OS assays. Plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined and analysed accordingly. At both 2- and 8-cell developing stages, actin intensities were significantly reduced in the nicotine group (p<0.001). After the intervention, actin intensity was significantly increased compared to that of the nicotine group (p<0.001). The same trend was seen in tubulin at both cell stages. TRF has minimized the deleterious effects of nicotine in actin and tubulin of both 2- and 8-cell developmental stages during pre-implantation embryonic development in mice in vitro. Levels of endogenous anti-oxidative enzymes were sustained close to control accompanied by decreased levels of OS biomarker.

Keywords: actin, nicotine, pre-implantation embryos, tocotrienol rich fraction, tubulin

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Authors: Ejaz Ahmed, Huang Yong

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The operation of aero engines has a critical importance in the vicinity of lean blowout (LBO) limits. Lefebvre’s model of LBO based on empirical correlation has been extended to flame volume concept by the authors. The flame volume takes into account the effects of geometric configuration, the complex spatial interaction of mixing, turbulence, heat transfer and combustion processes inside the gas turbine combustion chamber. For these reasons, flame volume based LBO predictions are more accurate. Although LBO prediction accuracy has improved, it poses a challenge associated with Vf estimation in real gas turbine combustors. This work extends the approach of flame volume prediction previously based on fuel iterative approximation with cold flow simulations to reactive flow simulations. Flame volume for 11 combustor configurations has been simulated and validated against experimental data. To make prediction methodology robust as required in the preliminary design stage, reactive flow simulations were carried out with the combination of probability density function (PDF) and discrete phase model (DPM) in FLUENT 15.0. The criterion for flame identification was defined. Two important parameters i.e. critical injection diameter (Dp,crit) and critical temperature (Tcrit) were identified, and their influence on reactive flow simulation was studied for Vf estimation. Obtained results exhibit ±15% error in Vf estimation with experimental data.

Keywords: CFD, combustion, gas turbine combustor, lean blowout

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Authors: Roghaieh Parvizsedghy, Seyyed Mojtaba Sadrameli

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Biodiesel as an alternative diesel fuel is steadily gaining more attention and significance. However, there are some drawbacks while using biodiesel regarding its properties that requires it to be blended with petrol based diesel and/or additives to improve the fuel characteristics. This study analyses thermal cracking as an alternative technology to improve biodiesel characteristics in which, FAME based biodiesel produced by transesterification of castor oil is fed into a continuous thermal cracking reactor at temperatures range of 450-500°C and flowrate range of 20-40 g/hr. Experiments designed by response surface methodology and subsequent statistical studies show that temperature and feed flowrate significantly affect the products yield. Response surfaces were used to study the impact of temperature and flowrate on the product properties. After each experiment, the produced crude bio-oil was distilled and diesel cut was separated. As shorter chain molecules are produced through thermal cracking, the distillation curve of the diesel cut fitted more with petrol based diesel curve in comparison to the biodiesel. Moreover, the produced diesel cut properties adequately pose within property ranges defined by the related standard of petrol based diesel. Cold flow properties, high heating value as the main drawbacks of the biodiesel are improved by this technology. Thermal cracking decreases kinematic viscosity, Flash point and cetane number.

Keywords: biodiesel, castor oil, fuel properties, thermal cracking

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Authors: Vipan Kumar Sohpal, Rajesh K Sharma

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Diminishing of conventional fuels and hysterical vehicles emission leads to deterioration of the environment, which emphasize the research to work on biofuels. Biofuels from different sources attract the attention of research due to low emission and biodegradability. Emission of carbon monoxide, carbon dioxide and H-C reduced drastically using Biofuels (B-20) combustion. Contrary to the conventional fuel, engine emission results indicated that nitrous oxide emission is higher in Biofuels. So this paper examines and compares the nitrogen oxide emission of Jatropha Curcus (JCO) B-20% blends with the vegetable oil. In addition to that computational analysis of crude non edible oil performed to assess the impact of composition on emission quality. In conclusion, JCO have the potential feedstock for the biodiesel production after the genetic modification in the plant.

Keywords: jatropha curcus, computational analysis, emissions, NOx biofuels

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Authors: Sara Pereira-Nogueira, Tim Worbs, Marc Permanyer-Bosser, Reinhold Förster

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While the entry mechanism of lymphocytes into the lymph node via the blood are well described, it is still largely unknown how cells enter lymph nodes that arrive via afferent lymphatics. In order to address this, our group has established a micro-injection technique in mice through which cells are delivered directly into the lymphatic vessel immediately afferent to the popliteal lymph node. Injected cells can then be tracked via multi-colour fluorescence or 2-photon microscopy, and their localization can be analysed within the popliteal or downstream lymph nodes by immunohistology. Since naïve B cells express the chemokine receptor CXCR5 we intra-lymphatically co-injected B cells derived from wildtype and Cxcr5-deficient mice. While CXCR5 does not play a role in guiding B cells out of the subcapsular sinus, it affects their positioning within the lymph node parenchyma, since CXCR5-deficient B cells are impaired in migrating into the B cell follicle. The knowledge obtained by studying B-cell migration may prove beneficial in clinical settings regarding tumor metastasis or autoimmune diseases.

Keywords: afferent lymphatics, B cell migration, chemokine, intra-lymphatic injection

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Authors: Jaroslav Knapek, Kamila Vavrova, Tomas Kralik, Tereza Humesova

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The treatment and disposal of sewage sludge is one of the most important and critical problems of waste water treatment plants. Currently, 180 thousand tonnes of sludge dry matter are produced in the Czech Republic, which corresponds to approximately 17.8 kg of stabilized sludge dry matter / year per inhabitant of the Czech Republic. Due to the fact that sewage sludge contains a large amount of substances that are not beneficial for human health, the conditions for sludge management will be significantly tightened in the Czech Republic since 2023. One of the tested methods of sludge liquidation is the production of alternative fuel from sludge from sewage treatment plants and paper production. The paper presents an analysis of economic efficiency of alternative fuel production from sludge and its use for fluidized bed boiler with nominal consumption of 5 t of fuel per hour. The evaluation methodology includes the entire logistics chain from sludge extraction, through mechanical moisture reduction to about 40%, transport to the pelletizing line, moisture drying for pelleting and pelleting itself. For economic analysis of sludge pellet production, a time horizon of 10 years corresponding to the expected lifetime of the critical components of the pelletizing line is chosen. The economic analysis of pelleting projects is based on a detailed analysis of reference pelleting technologies suitable for sludge pelleting. The analysis of the economic efficiency of pellet is based on the simulation of cash flows associated with the implementation of the project over the life of the project. For the entered value of return on the invested capital, the price of the resulting product (in EUR / GJ or in EUR / t) is searched to ensure that the net present value of the project is zero over the project lifetime. The investor then realizes the return on the investment in the amount of the discount used to calculate the net present value. The calculations take place in a real business environment (taxes, tax depreciation, inflation, etc.) and the inputs work with market prices. At the same time, the opportunity cost principle is respected; waste disposal for alternative fuels includes the saved costs of waste disposal. The methodology also respects the emission allowances saved due to the displacement of coal by alternative (bio) fuel. Preliminary results of testing of pellet production from sludge show that after suitable modifications of the pelletizer it is possible to produce sufficiently high quality pellets from sludge. A mixture of sludge and paper waste has proved to be a more suitable material for pelleting. At the same time, preliminary results of the analysis of the economic efficiency of this sludge disposal method show that, despite the relatively low calorific value of the fuel produced (about 10-11 MJ / kg), this sludge disposal method is economically competitive. This work has been supported by the Czech Technology Agency within the project TN01000048 Biorefining as circulation technology.

Keywords: Alternative fuel, Economic analysis, Pelleting, Sewage sludge

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Authors: A. Sekhar, N. Ramakrishna Raju

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This paper is a result of ground improvement using deep vibro techniques with combination of sand and stone columns performed on a highly liquefaction susceptible site (70 to 80% sand strata and balance silt) with low bearing capacities due to high settlements located (earth quake zone V as per IS code) at Madhepura, Bihar state in northern part of India. Initially, it was envisaged with bored cast in-situ/precast piles, stone/sand columns. However, after detail analysis to address both liquefaction and improve bearing capacities simultaneously, it was analyzed the deep vibro techniques with combination of sand and stone columns is excellent solution for given site condition which may be first time in India. First after detail soil investigation, pre eCPT test was conducted to evaluate the potential depth of liquefaction to densify silty sandy soils to improve factor of safety against liquefaction. Then trail test were being carried out at site by deep vibro compaction technique with sand and stone columns combination with different spacings of columns in triangular shape with different timings during each lift of vibro up to ground level. Different spacings and timing was done to obtain the most effective spacing and timing with vibro compaction technique to achieve maximum densification of saturated loose silty sandy soils uniformly for complete treated area. Then again, post eCPT test and plate load tests were conducted at all trail locations of different spacings and timing of sand and stone columns to evaluate the best results for obtaining the required factor of safety against liquefaction and the desired bearing capacities with reduced settlements for construction of industrial structures. After reviewing these results, it was noticed that the ground layers are densified more than the expected with improved factor of safety against liquefaction and achieved good bearing capacities for a given settlements as per IS codal provisions. It was also worked out for cost-effectiveness of lightly loaded single storied structures by using deep vibro technique with sand column avoiding stone. The results were observed satisfactory for resting the lightly loaded foundations. In this technique, the most important is to mitigating liquefaction with improved bearing capacities and reduced settlements to acceptable limits as per IS: 1904-1986 simultaneously up to a depth of 19M. To our best knowledge it was executed first time in India.

Keywords: ground improvement, deep vibro techniques, liquefaction, bearing capacity, settlement

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Authors: Beenish Saba, Ann D. Christy

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Modern day municipal solid waste landfills are operated and controlled to protect the environment from contaminants during the biological stabilization and degradation of the solid waste. They are equipped with liners, caps, gas and leachate collection systems. Landfill gas is passively or actively collected and can be used as bio fuel after necessary purification, but leachate treatment is the more difficult challenge. Leachate, if not recirculated in a bioreactor landfill system, is typically transported to a local wastewater treatment plant for treatment. These plants are designed for sewage treatment, and often charge additional fees for higher strength wastewaters such as leachate if they accept them at all. Different biological, chemical, physical and integrated techniques can be used to treat the leachate. Treating that leachate with simultaneous power production using microbial fuel cells (MFC) technology has been a recent innovation, reported its application in its earliest starting phase. High chemical oxygen demand (COD), ionic strength and salt concentration are some of the characteristics which make leachate an excellent substrate for power production in MFCs. Different materials of electrodes, microbial communities, carbon co-substrates and temperature conditions are some factors that can be optimized to achieve simultaneous power production and treatment. The advantage of the MFC is its dual functionality but lower power production and high costs are the hurdles in its commercialization and more widespread application. The studies so far suggest that landfill leachate MFCs can produce 1.8 mW/m2 with 79% COD removal, while amendment with food leachate or domestic wastewater can increase performance up to 18W/m3 with 90% COD removal. The columbic efficiency is reported to vary between 2-60%. However efforts towards biofilm optimization, efficient electron transport system studies and use of genetic tools can increase the efficiency of the MFC and can determine its future potential in treating landfill leachate.

Keywords: microbial fuel cell, landfill leachate, power generation, MFC

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Authors: Joana Pimenta, Lorena Coelho, José Silva, Vanessa Miranda, Jorge Laranjeira, Rui Soares

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In this paper, the results of R&D on an innovative food package for increased shelf-life are presented. SAP4MA aims at the development of a printed active device that enables smart packaging solutions for food preservation, targeting the extension of the shelf-life of the packed food through the controlled release of active natural antioxidant agents at the onset of the food degradation process. To do so, SAP4MA focuses on the development of active devices such as printed heaters and batteries/supercapacitors in a label format to be integrated on packaging lids during its injection molding process, promoting the passive release of natural antioxidants after the product is packed, during transportation and in the shelves, and actively when the end-user activates the package, just prior to consuming the product at home. When the active device present on the lid is activated, the release of the natural antioxidants embedded in the inner layer of the packaging lid in direct contact with the headspace atmosphere of the food package starts. This approach is based on the use of active functional coatings composed of nano encapsulated active agents (natural antioxidants species) in the prevention of the oxidation of lipid compounds in food by agents such as oxygen. Thus keeping the product quality during the shelf-life, not only when the user opens the packaging, but also during the period from food packaging up until the purchase by the consumer. The active systems that make up the printed smart label, heating circuit, and battery were developed using screen-printing technology. These systems must operate under the working conditions associated with this application. The printed heating circuit was studied using three different substrates and two different conductive inks. Inks were selected, taking into consideration that the printed circuits will be subjected to high pressures and temperatures during the injection molding process. The circuit must reach a homogeneous temperature of 40ºC in the entire area of the lid of the food tub, promoting a gradual and controlled release of the antioxidant agents. In addition, the circuit design involves a high level of study in order to guarantee maximum performance after the injection process and meet the specifications required by the control electronics component. Furthermore, to characterize the different heating circuits, the electrical resistance promoted by the conductive ink and the circuit design, as well as the thermal behavior of printed circuits on different substrates, were evaluated. In the injection molding process, the serpentine-shaped design developed for the heating circuit was able to resolve the issues connected to the injection point; in addition, the materials used in the support and printing had high mechanical resistance against the pressure and temperature inherent to the injection process. Acknowledgment: This research has been carried out within the Project “Smart and Active Packing for Margarine Product” (SAP4MA) running under the EURIPIDES Program being co-financed by COMPETE 2020 – the Operational Programme for Competitiveness and Internationalization and under Portugal 2020 through the European Regional Development Fund (ERDF).

Keywords: smart package, printed heat circuits, printed batteries, flexible and printed electronic

Procedia PDF Downloads 101

Authors: Samuel O. Alamu, Seong W. Lee, Blaise Kalmia, Marc J. Louise Caballes, Xuejun Qian

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The application of combustion technologies for thermal conversion of biomass and solid wastes to energy has been a major solution to the effective handling of wastes over a long period of time. Lab-scale biomass combustion systems have been observed to be economically viable and socially acceptable, but major concerns are the environmental impacts of the process and deviation of temperature distribution within the combustion chamber. Both high and low combustion chamber temperature may affect the overall combustion efficiency and gaseous emissions. Therefore, there is an urgent need to develop a control system which measures the deviations of chamber temperature from set target values, sends these deviations (which generates disturbances in the system) in the form of feedback signal (as input), and control operating conditions for correcting the errors. In this research study, major components of the feedback control system were determined, assembled, and tested. In addition, control algorithms were developed to actuate operating conditions (e.g., air velocity, fuel feeding rate) using ladder logic functions embedded in the Programmable Logic Controller (PLC). The developed control algorithm having chamber temperature as a feedback signal is integrated into the lab-scale swirling fluidized bed combustor (SFBC) to investigate the temperature distribution at different heights of the combustion chamber based on various operating conditions. The air blower rates and the fuel feeding rates obtained from automatic control operations were correlated with manual inputs. There was no observable difference in the correlated results, thus indicating that the written PLC program functions were adequate in designing the experimental study of the lab-scale SFBC. The experimental results were analyzed to study the effect of air velocity operating at 222-273 ft/min and fuel feeding rate of 60-90 rpm on the chamber temperature. The developed temperature-based feedback control system was shown to be adequate in controlling the airflow and the fuel feeding rate for the overall biomass combustion process as it helps to minimize the steady-state error.

Keywords: air flow, biomass combustion, feedback control signal, fuel feeding, ladder logic, programmable logic controller, temperature

Procedia PDF Downloads 124

Authors: Balram Panjwani, Bernd Wittgens, Jan Erik Olsen, Stein Tore Johansen

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The Norwegian ferroalloy industry is a world leader in sustainable production of ferrosilicon, silicon and manganese alloys with the lowest global specific energy consumption. One of the byproducts during the metal reduction process is energy rich off-gas and usually this energy is not harnessed. A novel concept for sustainable energy recovery from ferroalloy off-gas is discussed. The concept is founded on the idea of introducing a combustion chamber in the off-gas section in which energy rich off-gas mainly consisting of CO will be combusted. This will provide an additional degree of freedom for optimizing energy recovery. A well-controlled and high off-gas temperature will assure a significant increase in energy recovery and reduction of emissions to the atmosphere. Design and operation of the combustion chamber depend on many parameters, including the total power capacity of the combustion chamber, sufficient residence time for combusting the complex Poly Aromatic Hydrocarbon (PAH), NOx, as well as converting other potential pollutants. The design criteria for the combustion chamber have been identified and discussed and sizing of the combustion chamber has been carried out considering these design criteria. Computational Fluid Dynamics (CFD) has been utilized extensively for sizing the combustion chamber. The results from our CFD simulations of the flow in the combustion chamber and exploring different off-gas fuel composition are presented. In brief, the paper covers all aspect which impacts the sizing of the combustion chamber, including insulation thickness, choice of insulating material, heat transfer through extended surfaces, multi-staging and secondary air injection.

Keywords: CFD, combustion chamber, arc furnace, energy recovery

Procedia PDF Downloads 314

Authors: Narendra Akhadkar, Silvestre Cano, Christophe Gourru

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Injection-molded parts are widely used in power system protection products. One of the biggest challenges in an injection molding process is shrinkage and warpage of the molded parts. All these geometrical variations may have an adverse effect on the quality of the product, functionality, cost, and time-to-market. The situation becomes more challenging in the case of intricate shapes and in mass production using multi-cavity tools. To control the effects of shrinkage and warpage, it is very important to correctly find out the input parameters that could affect the product performance. With the advances in the computer-aided engineering (CAE), different tools are available to simulate the injection molding process. For our case study, we used the MoldFlow insight tool. Our aim is to predict the spread of the functional dimensions and geometrical variations on the part due to variations in the input parameters such as material viscosity, packing pressure, mold temperature, melt temperature, and injection speed. The input parameters may vary during batch production or due to variations in the machine process settings. To perform the accurate product assembly variation simulation, the first step is to perform an individual part variation simulation to render realistic tolerance ranges. In this article, we present a method to simulate part variations coming from the input parameters variation during batch production. The method is based on computer simulations and experimental validation using the full factorial design of experiments (DoE). The robustness of the simulation model is verified through input parameter wise sensitivity analysis study performed using simulations and experiments; all the results show a very good correlation in the material flow direction. There exists a non-linear interaction between material and the input process variables. It is observed that the parameters such as packing pressure, material, and mold temperature play an important role in spread on functional dimensions and geometrical variations. This method will allow us in the future to develop accurate/realistic virtual prototypes based on trusted simulated process variation and, therefore, increase the product quality and potentially decrease the time to market.

Keywords: correlation, molding process, tolerance, sensitivity analysis, variation simulation

Procedia PDF Downloads 172

Authors: Samarjeet Singh, Shubhank Arya, Shubham Chauhan

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In recent years, the rise in carbon emissions and the widespread effects of global warming have brought new energy vehicles into the spotlight. Electric vehicles (EVs) and hydrogen fuel cell vehicles (HFCVs), both producing zero tailpipe emissions, are seen as promising alternatives. This paper examines the working, structural characteristics, and safety designs of EVs and HFCVs, comparing their carbon emissions, charging infrastructure, energy efficiency, and safety features. The analysis reveals that both EVs and HFCVs significantly reduce carbon emissions and enhance safety compared to traditional vehicles, with EVs showing greater emission reductions. Moreover, EVs are advancing more rapidly in terms of charging infrastructure compared to hydrogen energy vehicles. However, HFCVs exhibit lower energy efficiency than EVs. In terms of safety, both types surpass conventional vehicles, though EVs are more prone to overheating and fire hazards due to battery design issues. Current research suggests that EV technology and its supporting infrastructure are more comprehensive, cost-effective, and efficient in reducing carbon emissions. With continued investment in the development of new energy vehicles and potential advancements in hydrogen energy production, the future for HFCVs appears promising. The paper also expresses optimism for innovative solutions that could accelerate the growth of hydrogen energy vehicles.

Keywords: electric vehicles, fuel cell electric vehicles, automotive engineering, energy transition

Procedia PDF Downloads 36

Authors: Rajkumar Ghosh

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The study examines the structural analysis of Chaura Thrust in Himachal Pradesh, India, focusing on the activation timing of Main Central Thrust (MCT) and South Tibetan Detachment System (STDS), mylonitised zones, and the characterization of box fold and its signature in the regional geology of Himachal Himalaya. The research aims to document the Higher Himalayan Out-of-Sequence Thrust (OOST) in Himachal Pradesh, which activated the MCTL and in between a zone south of MCTU. The study also documents the GBM-associated temperature range and the activation of Higher Himalayan Out-of-Sequence Thrust (OOST) in Himachal Pradesh. The findings contribute to understanding the structural analysis of Chaura Thrust and its signature in the regional geology of Himachal Himalaya. The study highlights the significance of microscopic studies in documenting mylonitized zones and identifying various types of crenulated schistosity. The study concludes that Chaura Thrust is not a blind thrust and details the field evidence for the OOST. The study characterizes the box fold and its signature in the regional geology of Himachal Himalaya. The study also documents the activation timing and ages of MCT, STDS, MBT, and MFT and identifies various types of crenulated schistosity under the microscope. The study also highlights the significance of microscopic studies in the structural analysis of Chaura Thrust. Finally, the study documents the activation of Higher Himalayan Out-of-Sequence Thrust (OOST) in Himachal Pradesh and the expectations for strain variation near the OOST.

Keywords: Chaura Thrust, Higher Himalaya, Jhakri Thrust, Main Central Thrust, Out-of-Sequence Thrust, Sarahan Thrust

Procedia PDF Downloads 82

Authors: Ameur Ameur Abdelkader, Boukherrouba Hadjira

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The aim of the present study was to evaluate different doses of PMSG on reproductive performance in Ouled Djellal ewes synchronized during the breeding season period. A total of 200 ewes were used in this experiment, were divided in two groups, 100 uniparous (A) and 100 multiparous (B). All animals in both groups were divided equally into four groups homogeneous lots of then a single intramuscular (IM) injection of PMSG, Lot T1, A1 (400 IU), A2 (500 IU), A3 (600 IU) and (lot T2, B1 (400 IU), B2 (500UI), B3 (600UI), T1, and T2 are batch control groups received a single injection of progestin treatment without PMSG. The results showed that the fertility rate ranges from 79.16% to 92% with no significant difference (P > 0.05) between uniparous and multiparous ewes. The prolificity rate varies from 100% to 140% in uniparous ewes with the respective doses of 0 IU for the control group and 600 IU for lot A3. A significant difference between multiparous ewes prolificacy and uniparous receiving 500UI PMSG (respectively 142% vs 109%). The productivity rate has increased significantly among uniparous ewes with 82% for lot A1 to 112.5% for lot A3, as in multiparous ewes 66.66% for lot B1 to 133.33% for lot B3. At the same we recorded a positive correlation between the number of born products and increasing the dose of PMSG injected into the two categories of ewes (112.5% to 133.33% for multiparous uniparous VS 83% for and 66.66 uniparous % for multiparous).

Keywords: Ouled djellal ewe, PMSG, reproductive performance, Fertility

Procedia PDF Downloads 431

Authors: M. Invigorito, G. Elia, M. Panelli

Abstract:

Hybrid propulsion combines beneficial properties of both solid and liquid rockets, such as multiple restarts, throttability as well as simplicity and reduced costs. A nitrous oxide (N2O)/paraffin-based hybrid rocket engine demonstrator is currently under development at the Italian Aerospace Research Center (CIRA) within the national research program HYPROB, funded by the Italian Ministry of Research. Nitrous oxide belongs to the class of self-pressurizing propellants that exhibit a high vapor pressure at standard ambient temperature. This peculiar feature makes those fluids very attractive for space rocket applications because it avoids the use of complex pressurization systems, leading to great benefits in terms of weight savings and reliability. To avoid feed-system-coupled instabilities, the phase change is required to occur through the injectors. In this regard, the oxidizer is stored in liquid condition while target chamber pressures are designed to lie below vapor pressure. The consequent cavitation and flash vaporization constitute a remarkably complex phenomenology that arises great modelling challenges. Thus, it is clear that the design of the injection system is fundamental for the full exploitation of hybrid rocket engine throttability. The Analytical Hierarchy Process has been used to select the injection architecture as best compromise among different design criteria such as functionality, technology innovation and cost. The impossibility to use engineering simplified relations for the dimensioning of the injectors led to the needs of applying a numerical approach based on OpenFOAM®. The numerical tool has been validated with selected experimental data from literature. Quantitative, as well as qualitative comparisons are performed in terms of mass flow rate and pressure drop across the injector for several operating conditions. The results show satisfactory agreement with the experimental data. Modeling assumptions, together with their impact on numerical predictions are discussed in the paper. Once assessed the reliability of the numerical tool, the injection plate has been designed and sized to guarantee the required amount of oxidizer in the combustion chamber and therefore to assure high combustion efficiency. To this purpose, the plate has been designed with multiple injectors whose number and diameter have been selected in order to reach the requested mass flow rate for the two operating conditions of maximum and minimum thrust. The overall design has been finally verified through three-dimensional computations in cavitating non-reacting conditions and it has been verified that the proposed design solution is able to guarantee the requested values of mass flow rates.

Keywords: hybrid rocket, injection system design, OpenFOAM®, cavitation

Procedia PDF Downloads 209