Search results for: external pressure

Authors: D. A. Bruzon, G. Tapang, I. S. Martinez

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Global warming and climate change are significant environmental concerns, which require immediate global action in carbon emission mitigation. The capture, sequestration, and conversion of carbon dioxide to other products such as methane or ethanol are ways to control excessive emissions. Ionic liquids have shown great potential among the materials studied as carbon capture solvents and catalysts in the reduction of CO2. In this study, ionic liquids comprising of a methoxy (-OCH3) and cyano (-CN) functionalized imidazolium cation, [MOBMIM] and [CNBMIM] respectively, paired with tris(pentafluoroethyl)trifluorophosphate [FAP] anion were evaluated as effective capture solvents, and organocatalysts in the reduction of CO2. An in-situ electrochemical set-up, which can measure controlled amounts of CO2 both in the gas and in the ionic liquid phase, was used. Initially, reduction potentials of CO2 in the CO2-saturated ionic liquids containing the internal standard cobaltocene were determined using cyclic voltammetry. Chronoamperometric transients were obtained at potentials slightly less negative than the reduction potentials of CO2 in each ionic liquid. The time-dependent current response was measured under a controlled atmosphere. Reduction potentials of CO2 in methoxy and cyano-functionalized [FAP] ionic liquids were observed to occur at ca. -1.0 V (vs. Cc+/Cc), which was significantly lower compared to the non-functionalized analog [PMIM][FAP], with an observed reduction potential of CO2 at -1.6 V (vs. Cc+/Cc). This decrease in the potential required for CO2 reduction in the functionalized ionic liquids shows that the functional groups methoxy and cyano effectively decreased the free energy of formation of the radical anion CO2●⁻, suggesting that these electrolytes may be used as organocatalysts in the reduction of the greenhouse gas. However, upon analyzing the solubility of the gas in each ionic liquid, [PMIM][FAP] showed the highest absorption capacity, at 4.81 mM under saturated conditions, compared to [MOBMIM][FAP] at 1.86 mM, and [CNBMIM][FAP] at 0.76 mM. Also, calculated Henry’s constant determined from the concentration-pressure graph of each functionalized ionic liquid shows that the groups -OCH3 and -CN attached terminal to a C4 alkyl chain do not significantly improve CO2 solubility.

Keywords: carbon capture, CO2 reduction, electrochemistry, ionic liquids

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Authors: Eisa Younes Alblooshi

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Counterterrorism strategies, to be effective and efficient, require a sound understanding of the dynamics, the interlinked organizational elements of the terrorist outfits being combated, with a view to having cognizance of their strong points to be guarded against, as well as the vulnerable zones that can be targeted for optimal results in a timely fashion by counterterrorism agencies. A unique model regarding the organizational imperatives was evolved in this research through likening the terrorist organizations with the traditional commercial ones, with a view to understanding in detail the dynamics of interconnectivity and dependencies, and the related compulsions facing the leaderships of such outfits that provide counterterrorism agencies with opportunities for forging better strategies. It involved assessing the evolving organizational dynamics and imperatives of different types of terrorist organizations, to enable the researcher to construct a prototype model that defines the progression and linkages of the related organizational elements of such organizations. It required detailed analysis of how the various elements are connected, with sequencing identified, as any outfit positions itself with respect to its external environment and internal dynamics. A case study focusing on a transnational radical religious state-sponsored terrorist organization was conducted to validate the research findings and to further strengthen the specific counterterrorism strategies. Six different variants of the business model of terrorist organizations were identified, categorized based on their outreach, mission, and status of any state sponsorship. The variants represent vast majority of the range of terrorist organizations acting locally or globally. The model shows the progression and dynamics of these organizations through various dimensions including mission, leadership, outreach, state sponsorship status, resulting in the organizational structure, state of autonomy, preference divergence in its fold, recruitment core, propagation avenues, down to their capacity to adapt, resulting critically in their own life cycles. A major advantage of the model is the utility of mapping terrorist organizations according to their fits to the sundry identified variants, allowing for flexibility and differences within, enabling the researchers and counterterrorism agencies to observe a neat blueprint of the organization’s footprint, along with highlighting the areas to be evaluated for focused target zone selection and timing of counterterrorism interventions. Special consideration is given to the dimension of financing, keeping in context the latest developments regarding cryptocurrencies, hawala, and global anti-money laundering initiatives. Specific counterterrorism strategies and intervention points have been identified for each of the respective model variants, with a view to efficient and effective deployment of resources.

Keywords: terrorism, counterterrorism, model, strategy

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Authors: Su Yin Chiam, Zhipeng Ding, Guang Yang, Danny Jian Hang Tng, Peiyi Song, Geok Ing Ng, Ken-Tye Yong, Qing Xin Zhang

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Brain-machine interfaces (BMI) is a ground rich of exploration opportunities where manipulation of neural activity are used for interconnect with myriad form of external devices. These research and intensive development were evolved into various areas from medical field, gaming and entertainment industry till safety and security field. The technology were extended for neurological disorders therapy such as obsessive compulsive disorder and Parkinson’s disease by introducing current pulses to specific region of the brain. Nonetheless, the work to develop a real-time observing, recording and altering of neural signal brain-machine interfaces system will require a significant amount of effort to overcome the obstacles in improving this system without delay in response. To date, feature size of interface devices and the density of the electrode population remain as a limitation in achieving seamless performance on BMI. Currently, the size of the BMI devices is ranging from 10 to 100 microns in terms of electrodes’ diameters. Henceforth, to accommodate the single cell level precise monitoring, smaller and denser Nano-scaled nanowire electrode arrays are vital in fabrication. In this paper, we would like to showcase the fabrication of high aspect ratio of vertical silicon nanowire electrodes arrays using microelectromechanical system (MEMS) method. Nanofabrication of the nanowire electrodes involves in deep reactive ion etching, thermal oxide thinning, electron-beam lithography patterning, sputtering of metal targets and bottom anti-reflection coating (BARC) etch. Metallization on the nanowire electrode tip is a prominent process to optimize the nanowire electrical conductivity and this step remains a challenge during fabrication. Metal electrodes were lithographically defined and yet these metal contacts outline a size scale that is larger than nanometer-scale building blocks hence further limiting potential advantages. Therefore, we present an integrated contact solution that overcomes this size constraint through self-aligned Nickel silicidation process on the tip of vertical silicon nanowire electrodes. A 4 x 4 array of vertical silicon nanowires electrodes with the diameter of 290nm and height of 3µm has been successfully fabricated.

Keywords: brain-machine interfaces, microelectromechanical systems (MEMS), nanowire, nickel silicide

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Authors: Ayesha Akbar

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Pakistan is moving from a security state to a welfare state despite several security challenges both internal and external. Human security signifies a varied approach in different regions depending upon the leadership and policy priorities. The link between human development and economic growth is not automatic. It has to be created consciously by forward-looking policies and strategies by national governments. There are seven components or categories of human security these include: Economic Security, Personal Security, Health Security, Environmental Security, Food Security, Community Security and Political Security. The increasing interest of the international community to clearly understand the dimensions of human security provided the grounds to Pakistani scholars as well to ponder on the issue and delineate lines of human security. A great deal of work has been either done or in process to evaluate human security indicators in Pakistan. Notwithstanding, after having been done a great deal of work the human security in Pakistan is not satisfactory. A range of deteriorating indicators of human development that lies under the domain of human security leaves certain inquiries to be answered. What are the dimensions of human security in Pakistan? And how are they being dealt from the perspective of policy and institution in terms of its operationalization in Pakistan? Is the human security discourse reflects evidence-based policy changes. The methodology is broadly based on qualitative methods that include interviews, content analysis of policy documents. Pakistan is among the most populous countries in the world and faces high vulnerability to climate change. Literacy rate has gone down with the surge of youth bulge to accommodate in the job market. Increasing population is creating food problems as the resources have not been able to compete with the raising demands of food and other social amenities of life. Majority of the people are facing acute poverty. Health outcomes are also not satisfactory with the high infant and maternal mortality rate. Pakistan is on the verge of facing water crisis as the water resources are depleting so fast with the high demand in agriculture and energy sector. Pakistan is striving hard to deal with the declining state of human security but the dilemma is lack of resources that hinders in meeting up with the emerging demands. The government requires to bring about more change with scaling-up economic growth avenues with enhancing the capacity of human resources. A modern performance drive culture with the integration of technology is required to deliver efficient and effective service delivery. On an already fast track process of reforms; e-governance and evidence based policy mechanism is being instilled in the government process for better governance and evidence based decisions.

Keywords: governance, human development index, human security, Pakistan, policy

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Authors: Velimir "monty" Vesselinov, Trais Kliplhuis, Hope Jasperson

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Artificial intelligence (AI) is a powerful tool in the geothermal energy sector, aiding in both exploration and utilization. Identifying promising geothermal sites can be challenging due to limited surface indicators and the need for expensive drilling to confirm subsurface resources. Geothermal reservoirs can be located deep underground and exhibit complex geological structures, making traditional exploration methods time-consuming and imprecise. AI algorithms can analyze vast datasets of geological, geophysical, and remote sensing data, including satellite imagery, seismic surveys, geochemistry, geology, etc. Machine learning algorithms can identify subtle patterns and relationships within this data, potentially revealing hidden geothermal potential in areas previously overlooked. To address these challenges, a SIML (Science-Informed Machine Learning) technology has been developed. SIML methods are different from traditional ML techniques. In both cases, the ML models are trained to predict the spatial distribution of an output (e.g., pressure, temperature, heat flux) based on a series of inputs (e.g., permeability, porosity, etc.). The traditional ML (a) relies on deep and wide neural networks (NNs) based on simple algebraic mappings to represent complex processes. In contrast, the SIML neurons incorporate complex mappings (including constitutive relationships and physics/chemistry models). This results in ML models that have a physical meaning and satisfy physics laws and constraints. The prototype of the developed software, called GeoTGO, is accessible through the cloud. Our software prototype demonstrates how different data sources can be made available for processing, executed demonstrative SIML analyses, and presents the results in a table and graphic form.

Keywords: science-informed machine learning, artificial inteligence, exploration, utilization, hidden geothermal

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Authors: Anies Mutiari, Neha Bansal, Martin Artner, Veronika Mayer, Juergen Roth, Mathias Weil, Rachmat Adhi Wibowo

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Cu₂ZnSnS₄ (CZTS) compound (mineral name kesterite) has attracted considerable interests for photovoltaic application owing to its optoelectrical properties. Moreover, its elemental abundance in Earth’s crust offers a comparative advantage for envisaged large-scale photovoltaic deployment without any material shortage issues. In this contribution, we present an innovative route to prepare CZTS solar absorber layer for photovoltaic application from low-cost and up-scalable process. CZTS layers were spin coated on the Molybdenum-coated glass from two inks composed of different solvents; dimethylsulfoxide (DMSO) and ultrapure water. Into each solvent; 0.57M CuCl₂, 0.39M ZnCl₂, 0.53M SnCl₂, and 1.85M Thiourea or Na₂S₂O₃, as well as pre-synthesized CZTS nanopowder, were added as sources of Cu, Zn, Sn and S in the ink. The crystallisation of ink into CZTS dense layers was carried out by firstly annealing the as-deposited CZTS layer in open air at 300°C for 1 minute, followed by sulfurisation at 560–620°C under atmospheric pressure for 120 minutes. Complementary electron microscopy, grazing incidence X-ray diffraction and Raman spectroscopy investigations suggest that both solvents can be used for preparing high quality and device relevant CZTS solar absorber layers. The sulphurisation crystallizes the as-deposited CZTS into highly polycrystalline CZTS layer with tetragonal structure demonstrated by the presence of tetrahedrally-shaped grains with the size of 1 µm. An advancement of the CZTS layer preparation was made by gradual substitution of volatile organic compound solvent of DMSO with ultrapure water. It is revealed that by using similar air annealing and sulphurisation process, dense and compact CZTS layers can also be fabricated from an ink with reduced volatile organic compound content.

Keywords: kesterite, solar ink, spin coating, photovoltaics

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Authors: Anupoju Rajeev, Joanne Mathew, Amit Shelke

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In the current study, a new type of Composite Structural Insulated Panels (CSIPs) is developed and investigated its performance against shock loading which can replace the conventional wooden structural materials. The CSIPs is made of Fibre Cement Board (FCB)/aluminum as the facesheet and the expanded polystyrene foam as the core material. As tornadoes are very often in the western countries, it is suggestable to monitor the health of the CSIPs during its lifetime. So, the composite structure is installed with three smart sensors located randomly at definite locations. Each smart sensor is fabricated with an embedded half stainless phononic crystal sensor attached to both ends of the nylon shaft that can resist the shock and impact on facesheet as well as polystyrene foam core and safeguards the system. In addition to the granular crystal sensors, the accelerometers are used in the horizontal spanning and vertical spanning with a definite offset distance. To estimate the health and damage of the CSIP panel using granular crystal sensor, shock wave loading experiments are conducted. During the experiments, the time of flight response from the granular sensors is measured. The main objective of conducting shock wave loading experiments on the CSIP panels is to study the effect and the sustaining capacity of the CSIP panels in the extreme hazardous situations like tornados and hurricanes which are very common in western countries. The effects have been replicated using a shock tube, an instrument that can be used to create the same wind and pressure intensity of tornado for the experimental study. Numerous experiments have been conducted to investigate the flexural strength of the CSIP. Furthermore, the study includes the damage detection using three smart sensors embedded in the CSIPs during the shock wave loading.

Keywords: composite structural insulated panels, damage detection, flexural strength, sandwich structures, shock wave loading

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Authors: Vandana Dave, Neelam Kumari

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India, a fast growing global power, is climbing the ladder of success very swiftly and has been attracting the world’s attention in recent decades. But unfortunately in the modern society, women who constitute half the population of our country have been the victims of violence in different fields of life both physically, socially, mentally and economically. Women face a lot of societal pressure, gender based violence – including rape, domestic violence, dowry death, murder and sexual abuse. But none the less, it is not considered as a problem of serious concern. Among the issues related to women, domestic violence is one of the major issue in our society which is occurring within the safe confines of home at the hands of close family members and cuts across line of race, nationality, language, culture, economics, sexual orientation, physical ability and religion to affect women from all walks of life. It is not to be perceived as a law and order problem alone but it is a socio- cultural problem and it is directly affecting the family life, health of women and life of children. Structural imbalance of power, systematic gender based discrimination; inequality between women and men and other kind of subordination are the context and cause of violence against women. Understanding it as a major problem of our society, the present study was conducted to assess the status of women of Rohtak, district of Haryana. The present study is based on primary and secondary data, adopting feminist research methodology. Case study method was incorporated during the research. It was observed that violence varied according to different age groups of women, marital status, education status, economic status and sociodemography factors. The case studies depicted the inadequate justice system for the victims of domestic violence. The study also revealed that the victims failed to understand the judiciary system and considered themselves helpless and hopeless. The study indicates the need of women friendly justice system for the upliftment of the society.

Keywords: domestic violence, women, victim, justice

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Authors: Liaqat Ali, Ehsan, Muhammad Shahzad, Nasir Orakzai

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Introduction: Internal optical urethrotomy is the main stay treatment modality in management of urethral stricture. Being minimal invasive with less morbidity, it is commonly performed and favored procedure by urologists across the globe. Although short-term success rate of optical urethrotomy is promising but long-term efficacy of IOU is questionable with high recurrence rate in different studies. Numerous techniques had been adopted to reduce the recurrence after IOU like prolong catheterization and self-clean intermittent catheterization with varying success. Mitomycin C has anti-fibroblast and anti-collagen properties and has been used in trabeculectomy, myringotomy and after keloid scar excision in contemporary surgical practice. Present study according to the best of our knowledge is a pioneer pilot study in Pakistan to determine the efficacy of Mitomycin C in preventing recurrence of urethral stricture after internal optical urethrotomy. Objective: To determine the efficacy of Mitomycin C in reducing the recurrence of anterior urethral stricture after internal optical urethrotomy. Methods: It is a randomized control trial conducted in department of urology, Institute of Kidney Diseases Hayatabad Medical Complex Peshawar from March 2011 till December 2013. After approval of hospital ethical committee, we included maximum of 2 cm anterior urethral stricture irrespective of etiology. Total of 140 patients were equally divided into two groups by lottery method. Group A (Case) comprising of 70 patients in whom Mitomycin C 0.1% was injected sub mucosal in stricture area at 1,11,6 and 12 O clock position using straight working channel paediatric cystoscope after conventional optical urethrotomy. Group B (Control) 70 patients in whom only optical urethrotomy was performed. SCIC was not offered in both the groups. All the patients were regularly followed on a monthly basis for 3 months then three monthly for remaining 9 months. Recurrence was diagnosed by using diagnostic tools of retrograde urethrogram and flexible urethroscopy in selected cased. Data was collected on structured Proforma and was analyzed on SPSS. Result: The mean age in Group A was 33 ±1.5 years and Group B was 35 years. External trauma was leading cause of urethral stricture in both groups 46 (65%) Group A and 50 (71.4%) Group B. In Group A. Iatrogenic urethral trauma was 2nd etiological factor in both groups. 18(25%) Group A while 15( 21.4%) in Group B. At the end of 1 year, At the end of one year, recurrence of urethral stricture was recorded in 11 (15.71%) patient in Mitomycin C Group A and it was recorded in 27 (38.5 %) patients in group B. Significant difference p=0.001 was found in favour of group A Mitomycin group. Conclusion: Recurrence of urethral stricture is high after optical urethrotomy. Mitomycin C is found highly effective in preventing recurrence of urethral stricture after IOU.

Keywords: urethral stricture, mitomycine, internal optical urethrotomy, medical and health sciences

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Authors: Ariba Siddiqui, Amber Khan

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The need for bio-implantable devices in the field of medical sciences has been increasing day by day; however, the charging of these devices is a major issue. Batteries, a very common method of powering the implants, have a limited lifetime and bulky nature. Therefore, as a replacement of batteries, acoustic power transfer (APT) technology is being accepted as the most suitable technique to wirelessly power the medical implants in the present scenario. The basic model of APT consists of piezoelectric transducers that work on the principle of converse piezoelectric effect at the transmitting end and direct piezoelectric effect at the receiving end. This paper provides mechanistic insight into the parameters affecting the design and efficient working of acoustic power transfer systems. The optimum design considerations have been presented that will help to compress the size of the device and augment the intensity of the pressure wave. A COMSOL model of the PZT (Lead Zirconate Titanate) transducer was developed. The model was simulated and analyzed on a frequency spectrum. The simulation results displayed that the efficiency of these devices is strongly dependent on the frequency of operation, and a wrong choice of the operating frequency leads to the high absorption of acoustic field inside the tissue (medium), poor power strength, and heavy transducers, which in effect influence the overall configuration of the acoustic systems. Considering all the tradeoffs, the simulations were performed again by determining an optimum frequency (900 kHz) that resulted in the reduction of the transducer's thickness to 1.96 mm and augmented the power strength with an intensity of 432 W/m². Thus, the results obtained after the second simulation contribute to lesser attenuation, lightweight systems, high power intensity, and also comply with safety limits provided by the U.S Food and Drug Administration (FDA). It was also found that the chosen operating frequency enhances the directivity of the acoustic wave at the receiver side.

Keywords: acoustic power, bio-implantable, COMSOL, Lead Zirconate Titanate, piezoelectric, transducer

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Authors: I. M. Salama, R. N. Miftahof

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A functional element of the myenteric nervous plexus is a morphologically distinct ganglion. Composed of sensory, inter- and motor neurons and arranged via synapses in neuronal circuits, their task is to decipher and integrate spike coded information within the plexus into regulatory output signals. The stability of signal processing in response to a wide range of internal/external perturbations depends on the plasticity of individual neurons. Any aberrations in this inherent property may lead to instability with the development of a dynamics chaos and can be manifested as pathological conditions, such as intestinal dysrhythmia, irritable bowel syndrome. The aim of this study is to investigate patterns of signal transduction within a two-neuronal chain - a ganglion - under normal physiological and structurally altered states. The ganglion contains the primary sensory (AH-type) and motor (S-type) neurons linked through a cholinergic dendro somatic synapse. The neurons have distinguished electrophysiological characteristics including levels of the resting and threshold membrane potentials and spiking activity. These are results of ionic channel dynamics namely: Na+, K+, Ca++- activated K+, Ca++ and Cl-. Mechanical stretches of various intensities and frequencies are applied at the receptive field of the AH-neuron generate a cascade of electrochemical events along the chain. At low frequencies, ν < 0.3 Hz, neurons demonstrate strong connectivity and coherent firing. The AH-neuron shows phasic bursting with spike frequency adaptation while the S-neuron responds with tonic bursts. At high frequency, ν > 0.5 Hz, the pattern of electrical activity changes to rebound and mixed mode bursting, respectively, indicating ganglionic loss of plasticity and adaptability. A simultaneous increase in neuronal conductivity for Na+, K+ and Ca++ ions results in tonic mixed spiking of the sensory neuron and class 2 excitability of the motor neuron. Although the signal transduction along the chain remains stable the synchrony in firing pattern is not maintained and the number of discharges of the S-type neuron is significantly reduced. A concomitant increase in Ca++- activated K+ and a decrease in K+ in conductivities re-establishes weak connectivity between the two neurons and converts their firing pattern to a bistable mode. It is thus demonstrated that neuronal plasticity and adaptability have a stabilizing effect on the dynamics of signal processing in the ganglion. Functional modulations of neuronal ion channel permeability, achieved in vivo and in vitro pharmacologically, can improve connectivity between neurons. These findings are consistent with experimental electrophysiological recordings from myenteric ganglia in intestinal dysrhythmia and suggest possible pathophysiological mechanisms.

Keywords: neuronal chain, signal transduction, plasticity, stability

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Authors: Sami Aboujafar

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Oil recovery in petroleum reservoirs is greatly affected by fluid-rock and fluid-fluid interactions. These interactions directly control rock wettability, capillary pressure and relative permeability curves. Laboratory core-floods and centrifuge experiments were conducted on sandstone and carbonate cores to study the effect of low and high brine salinity and viscosity and oil viscosity on residual saturations and relative permeability. Drainage and imbibition relative permeability in two phase system were measured, refined lab oils with different viscosities, heavy and light, and several brine salinities were used. Sensitivity analysis with different values for the salinity and viscosity of the fluids,, oil and water, were done to investigate the effect of these properties on water/oil relative permeability, residual oil saturation and oil recovery. Experiments were conducted on core material from viscous/heavy and light oil fields. History matching core flood simulator was used to study how the relative permeability curves and end point saturations were affected by different fluid properties using several correlations. Results were compared with field data and literature data. The results indicate that there is a correlation between the oil viscosity and/or brine salinity and residual oil saturation and water relative permeability end point. Increasing oil viscosity reduces the Krw@Sor and increases Sor. The remaining oil saturation from laboratory measurements might be too high due to experimental procedures, capillary end effect and early termination of the experiment, especially when using heavy/viscous oil. Similarly the Krw@Sor may be too low. The effect of wettability on the observed results is also discussed. A consistent relationship has been drawn between the fluid parameters, water/oil relative permeability and residual saturations, and a descriptor may be derived to define different flow behaviors. The results of this work will have application to producing fields and the methodologies developed could have wider application to sandstone and carbonate reservoirs worldwide.

Keywords: history matching core flood simulator, oil recovery, relative permeability, residual saturations

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Authors: Pavel Borodkin, Nikolay Khrennikov, Azamat Gazetdinov

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The problem of ensuring of VVER type reactor equipment integrity is now most actual in connection with justification of safety of the NPP Units and extension of their service life to 60 years and more. First of all, it concerns old units with VVER-440 and VVER-1000. The justification of the VVER equipment integrity depends on the reliability of estimation of the degree of the equipment damage. One of the mandatory requirements, providing the reliability of such estimation, and also evaluation of VVER equipment lifetime, is the monitoring of equipment radiation loading parameters. In this connection, there is a problem of justification of such normative parameters, used for an estimation of the pressure vessel metal embrittlement, as the fluence and fluence rate (FR) of fast neutrons above 0.5 MeV. From the point of view of regulatory practice, a comparison of displacement per atom (DPA) and fast neutron fluence (FNF) above 0.5 MeV has a practical concern. In accordance with the Russian regulatory rules, neutron fluence F(E > 0.5 MeV) is a radiation exposure parameter used in steel embrittlement prediction under neutron irradiation. However, the DPA parameter is a more physically legitimate quantity of neutron damage of Fe based materials. If DPA distribution in reactor structures is more conservative as neutron fluence, this case should attract the attention of the regulatory authority. The purpose of this work was to show what radiation load parameters (fluence, DPA) on all VVER equipment should be under control, and give the reasonable estimations of such parameters in the volume of all equipment. The second task is to give the conservative estimation of each parameter including its uncertainty. Results of recently received investigations allow to test the conservatism of calculational predictions, and, as it has been shown in the paper, combination of ex-vessel measured data with calculated ones allows to assess unpredicted uncertainties which are results of specific unique features of individual equipment for VVER reactor. Some results of calculational-experimental investigations are presented in this paper.

Keywords: equipment integrity, fluence, displacement per atom, nuclear power plant, neutron activation measurements, neutron transport calculations

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Authors: Yoftahe Nigussie

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This research explores the implementation of a vapor absorption refrigeration system (VARS) in mini-bus cars to enhance air conditioning efficiency. The conventional vapor compression refrigeration system (VCRS) in vehicles relies on mechanical work from the engine, leading to increased fuel consumption. The proposed VARS aims to utilize waste heat and exhaust gas from the internal combustion engine to cool the mini-bus cabin, thereby reducing fuel consumption and atmospheric pollution. The project involves two models: Model 1, a two-fluid vapor absorption system (VAS), and Model 2, a three-fluid VAS. Model 1 uses ammonia (NH₃) and water (H₂O) as refrigerants, where water absorbs ammonia rapidly, producing a cooling effect. The absorption cycle operates on the principle that absorbing ammonia in water decreases vapor pressure. The ammonia-water solution undergoes cycles of desorption, condensation, expansion, and absorption, facilitated by a generator, condenser, expansion valve, and absorber. The objectives of this research include reducing atmospheric pollution, minimizing air conditioning maintenance costs, lowering capital costs, enhancing fuel economy, and eliminating the need for a compressor. The comparison between vapor absorption and compression systems reveals advantages such as smoother operation, fewer moving parts, and the ability to work at lower evaporator pressures without affecting the Coefficient of Performance (COP). The proposed VARS demonstrates potential benefits for mini-bus air conditioning systems, providing a sustainable and energy-efficient alternative. By utilizing waste heat and exhaust gas, this system contributes to environmental preservation while addressing economic considerations for vehicle owners. Further research and development in this area could lead to the widespread adoption of vapor absorption technology in automotive air conditioning systems.

Keywords: room, zone, space, thermal resistance

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Authors: Ozan Kahraman, Hao Feng

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Manothermosonication (MTS), which consists of the simultaneous application of heat and ultrasound under moderate pressure (100-700 kPa), is one of the technologies which destroy microorganisms and inactivates enzymes. Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it. The environmental scanning electron microscope or ESEM is a scanning electron microscope (SEM) that allows for the option of collecting electron micrographs of specimens that are "wet," uncoated. These microscopy techniques allow us to observe the processing effects on the samples. This study was conducted to investigate the effects of MTS and HTST treatments on the morphology of apple-carrot juices by using TEM and ESEM microscopy. Apple-carrot juices treated with HTST (72 0C, 15 s), MTS 50 °C (60 s, 200 kPa), and MTS 60 °C (30 s, 200 kPa) were observed in both ESEM and TEM microscopy. For TEM analysis, a drop of the solution dispersed in fixative solution was put onto a Parafilm ® sheet. The copper coated side of the TEM sample holder grid was gently laid on top of the droplet and incubated for 15 min. A drop of a 7% uranyl acetate solution was added and held for 2 min. The grid was then removed from the droplet and allowed to dry at room temperature and presented into the TEM. For ESEM analysis, a critical point drying of the filters was performed using a critical point dryer (CPD) (Samdri PVT- 3D, Tousimis Research Corp., Rockville, MD, USA). After the CPD, each filter was mounted onto a stub and coated with gold/palladium with a sputter coater (Desk II TSC Denton Vacuum, Moorestown, NJ, USA). E.Coli O157:H7 cells on the filters were observed with an ESEM (Philips XL30 ESEM-FEG, FEI Co., Eindhoven, The Netherland). ESEM (Environmental Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) images showed extensive damage for the samples treated with MTS at 50 and 60 °C such as ruptured cells and breakage on cell membranes. The damage was increasing with increasing exposure time.

Keywords: MTS, HTST, ESEM, TEM, E.COLI O157:H7

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Authors: Majid Farsadrouh Rashti, Amir Shafiee Kisomi, Parisa Jahani

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The direct ethanol fuel cells (DEFCs) are contemplated as a promising energy source because, In addition to being used in portable electronic devices, it is also used for electric vehicles. The synthesis of bimetallic nanostructures due to their novel optical, catalytic and electronic characteristic which is precisely in contrast to their monometallic counterparts is attracting extensive attention. Galvanic replacement (sometimes is named to as cementation or immersion plating) is an uncomplicated and effective technique for making nanostructures (such as core-shell) of different metals, semiconductors, and their application in DEFCs. The replacement of galvanic does not need any external power supply compared to electrodeposition. In addition, it is different from electroless deposition because there is no need for a reducing agent to replace galvanizing. In this paper, a fast method for the palladium (Pd) wire nanostructures synthesis with the great surface area through galvanic replacement reaction utilizing copper nanowires (CuNWS) as a template by the assistance of ultrasound under room temperature condition is proposed. To evaluate the morphology and composition of Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan, emission scanning electron microscopy, energy dispersive X-ray spectroscopy were applied. In order to measure the phase structure of the electrocatalysts were performed via room temperature X-ray powder diffraction (XRD) applying an X-ray diffractometer. Various electrochemical techniques including chronoamperometry and cyclic voltammetry were utilized for the electrocatalytic activity of ethanol electrooxidation and durability in basic solution. Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan catalyst demonstrated substantially enhanced performance and long-term stability for ethanol electrooxidation in the basic solution in comparison to commercial Pd/C that demonstrated the potential in utilizing Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan as efficient catalysts towards ethanol oxidation. Noticeably, the Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan presented excellent catalytic activities with a peak current density of 320.73 mAcm² which was 9.5 times more than in comparison to Pd/C (34.2133 mAcm²). Additionally, activation energy thermodynamic and kinetic evaluations revealed that the Pd@ Copper nanowires/MultiWalled Carbon nanotubes-Chitosan catalyst has lower compared to Pd/C which leads to a lower energy barrier and an excellent charge transfer rate towards ethanol oxidation.

Keywords: core-shell structure, electrocatalyst, ethanol oxidation, galvanic replacement reaction

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Authors: Kehinde Joseph Awosan, Balarabe Adami Isah, Edzu Usman Yunusa, Sarafadeen Adeniyi Arisegi, Izuchukwu Obasi, Oluchi Solomon-Anucha

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Background: Metabolic syndrome (MetS) is prevalent in patients with diabetes mellitus and a significant risk for major cardiovascular events. Identifying its burden and peculiarities is crucial to preventing complications among those at risk. Aim: This study was conducted to determine the prevalence and predictors of metabolic syndrome among diabetes clinic attendees in Sokoto, Nigeria. Materials and Methods: A cross-sectional study was conducted among 365 patients with type 2 diabetes attending the diabetes clinic of Specialist Hospital, Sokoto, Nigeria. A structured questionnaire was used to obtain data on the respondents’ socio-demographic variables, treatment history, and lifestyle. Blood pressure and anthropometric measurements (including weight, height, and waist circumference) were done for the patients. Likewise, biochemical assessment (including fasting plasma glucose, high-density lipoprotein cholesterol (HDL-c), and triglyceride (TG) was done. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III). Data were analyzed using the IBM Statistical Package for Social Sciences (SPSS) version 25. Results: The ages of the patients ranged from 30 to 78 (mean = 50.9 ±11.7) years. The overall prevalence of MetS was 57.3%, with a higher prevalence in females (68.1%) than males (43.0%). The most common components of MetS observed were hypertension (69.2%), and elevated fasting plasma glucose (65.7%); while the predictors of MetS were age > 50 years (OR 6.960, 95% CI: 3.836-12.628, p < 0.001), female sex (OR 2.300, 95% CI: 1.355-3.903, p = 0.002), physical activity (OR 0.214, 95% CI: 0.126-0.363, p < 0.001), and overweight/obesity (OR 3.356, 95% CI: 1.838-6.127, p < 0.001). Conclusion: Metabolic syndrome is prevalent among patients with type 2 diabetes in Sokoto, Nigeria, and the predictors were age > 50 years, female sex, physical activity, and overweight/obesity. Diabetes care providers should screen their patients for MetS to prevent adverse cardiovascular events.

Keywords: prevalence, predictors, metabolic syndrome, diabetes

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Authors: Renee Yi-Mond Yuan

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The fast development of tourism industries around the world, has largely contributed to many cities, and countries economical and social progress. Past year Taiwan in particular was ranked among one of fastest raise growth country. Thanks to the prominent importance of this phenomenon; seasonal mobility or multipurpose trips have reached more than 1 Billion tourists crossing International borders and more than 4 billion intramural travelers that have nourished the economy and employment in the service sector in most attractive regions, representing about one tenth of World GDP amount, including trade, research, cultural or journalistic purposes. Then the increased activities are giving pressure to the consumption of energy, water, resources, and Greenhouse Gas emissions. The further concentration of tourists in most beautiful sites of the World with consistent supply and reduced pollutions and means for waste control and risks management are challenging the preservation and protection of the natural original environment, including species and their ecosystems, ethnics and their cultures or languages, protection of inherited landscapes and monuments for the future generations to come. In this article, few projects will be analyzed, methods and directions in the EU sustainable development scheme giving way to economical and social activities and preserve rural areas and remote countryside as well as smarter cities development. EU ETS forecasting escalation in the next few decades for road and air, and will reconsider investments and reliance on Biobased alternatives that may turn out solutions and contributions to sustain popularization of tourism development. Study of Examples of Stakeholders practices and Governments efforts, consumer’s attitude to bring new forms of more responsible holidays models: ecotourism, eco-certification, partnerships, investment in technologies and facilities, and possibly create greener perceptions and less impacting demands for the longer term through association, organizations and awards.

Keywords: tourism, sustainability, protection, risks management, change in rural/urban environment

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Authors: Qianhui Li, Christoph H. Bruecker

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Atherosclerotic plaques are typically found where flow separation and variations of shear stress occur. Although helical flow patterns and flow separations have been recorded in the aorta, their relation has not been clearly clarified and especially in the condition of artificial heart valve prostheses. Therefore, an experimental study is performed to investigate the hemodynamic performance of different mechanical heart valves (MHVs), i.e. the SJM Regent bileaflet mechanical heart valve (BMHV) and the Lapeyre-Triflo FURTIVA trileaflet mechanical heart valve (TMHV), in a transparent model of the human aorta under a physiological pulsatile right-hand helical flow condition. A typical systolic flow profile is applied in the pulse-duplicator to generate a physiological pulsatile flow which thereafter flows past an axial turbine blade structure to imitate the right-hand helical flow induced in the left ventricle. High-speed particle image velocimetry (PIV) measurements are used to map the flow evolution. A circular open orifice nozzle inserted in the valve plane as the reference configuration initially replaces the valve under investigation to understand the hemodynamic effects of the entered helical flow structure on the flow evolution in the aortic arch. Flow field analysis of the open orifice nozzle configuration illuminates the helical flow effectively delays the flow separation at the inner radius wall of the aortic arch. The comparison of the flow evolution for different MHVs shows that the BMHV works like a flow straightener which re-configures the helical flow pattern into three parallel jets (two side-orifice jets and the central orifice jet) while the TMHV preserves the helical flow structure and therefore prevent the flow separation at the inner radius wall of the aortic arch. Therefore the TMHV is of better hemodynamic performance and reduces the pressure loss.

Keywords: flow separation, helical aortic flow, mechanical heart valve, particle image velocimetry

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Authors: J. M. Alzate, J. Baena

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This work presents the final results of the ‘Diagnosis of the hydrological and hydrogeological potential in the Mancomojan basin for estimations of offer and demand’ with the purpose of obtaining solutions of domestic supply for the communities of the zone of study. There was realized the projection of population of the paths by three different scenes. The highest water total demand appears with the considerations of the scene 3, with a total demand for the year 2050 of 59.275 m3/year (1,88 l/s), being the path San Francisco the one that exercises a major pressure on the resource with a demand for the same year of the order of 31.189 m3/year (0,99 l/s). As for the hydrogeological potential of the zone and as alternative of supply of the studied communities, the stratigraphic columns obtained of the geophysical polls do not show strata saturated with water that could be considered to be a potential source of supply for the communities. The water registered in the geophysics tests presents very low resistances what indicates that he presents ions, this water meets in the rock interstices very thin granulometries which indicates that it is a water of constitution, and the flow of this one towards more permeable granulometries is void or limited. The underground resource that is registered so much in electrical vertical polls (SEV) as in tomography and that is saturating rocks of thin granulometry (clays and slimes), was demonstrated by content of ions, which is consistent with the abundant presence of plaster and the genesis marinades with transition to continental of the geological units in the zone. Predominant rocks are sedimentary, sandy rocks of grain I die principally, in minor proportion were observed also sandstones of thick grain to conglomerate with clastic rock of quartz, chert and siltstone of the Formation Mess and sandstones (of thin, average and thick grain) alternating with caps conglomerate whose thickness is, in general, between 5 and 15 cm, the nodules of sandstones are frequent with the same composition of the sandstones that contain them, in some cases with calcareous and crossed stratification of the formation Sincelejo Miembro Morroa.

Keywords: hydrological, hydrogeological potential, geotomography, vertical electrical sounding (VES)

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Authors: Masoud Ghaemi, MohammadJafar Hedayati, Faezeh Yousefzadeh, Hoseinali Heydarzadeh

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According to the statistics of the International Committee on Large Dams, internal erosion and piping (scour) are major causes of the destruction of earth-fill dams. If such dams are constructed in narrow valleys, the valley walls will increase the arching of the dam body due to the transfer of vertical and horizontal stresses, so the occurrence of hydraulic fracturing in these embankments is more likely. Roudbar Dam in Lorestan is a clay-core pebble earth-fill dam constructed in a relatively narrow valley in western Iran. Three years after the onset of impoundment, there has been a fall in dam behavior. Evaluation of the dam behavior based on the data recorded on the instruments installed inside the dam body and foundation confirms the occurrence of internal erosion in the lower and adjacent parts of the core on the left support (abutment). The phenomenon of hydraulic fracturing is one of the main causes of the onset of internal erosion in this dam. Accordingly, the main objective of this paper is to evaluate the validity of this hypothesis. To evaluate the validity of this hypothesis, the dam behavior during construction and impoundment has been first simulated with a three-dimensional numerical model. Then, using validated empirical equations, the safety factor of the occurrence of hydraulic fracturing phenomenon upstream of the dam score was calculated. Then, using the artificial neural network, the failure time of the given section was predicted based on the maximum stress trend created. The study results show that steep slopes of valley walls, sudden changes in coefficient, and differences in compressibility properties of dam body materials have caused considerable stress transfer from core to adjacent valley walls, especially at its lower levels. This has resulted in the coefficient of confidence of the occurrence of hydraulic fracturing in each of these areas being close to one in each of the empirical equations used.

Keywords: arching, artificial neural network, FLAC3D, hydraulic fracturing, internal erosion, pore water pressure

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Authors: Matias Hargreaves, Martin Del Valle, Diego Rodriguez, Riveros Jose Luis

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Trough years, all kind of social development projects have tried to solve social problems such as hunger, poverty, malnutrition, food insecurity, among others, with poor success. Both private and state initiatives have invested resources in several countries and communities. Nevertheless, most of these initiatives are scientific or external developers-centered, with a lack of local participation. This compromises the sustainability of any intervention and also leads to a poor empowerment of local community. The participatory approach aims to rescue and enhance the local knowledge since it recognizes that this kind of problems are better known by native actors. The objective of the study was to describe the role played by the community empowerment on food security improvement in the NGO “O Viveiro” (15°43'37.77"S; 32°46'27.53"E) and Barrio Broma village (15°43'58.78"S; 32°46'7.27"E) in Chitima, Mozambique. A center for training in goat livestock and orchard was build. A community orchard was co-constructed between foreign technicians and local actors. The prototype was installed in February, 2016 by the technician team and local community with 16 m2 as a nursery garden. Two orchard workshops were conducted in order to design a sustainable productive model which mixes both local and technological approaches. Two goat meat workshops were conducted in order to describe local methods and train the community to conduce their own techniques with high sanitary and productive standards. Technician team stayed in Mozambique until May, 2016. The quorum for the orchard workshops was 20 and 14 persons respectively, which represents 100% and 70%of the total requested quorum (20). For the goat meat workshops were 4 and 5 persons, which representa80% and 100% of the total requested quorum (5). Until August, 2016, the orchard is 3.219 m2 and it grows several vegetables as beans, chili pepper, garlic, onion, tomatoes, lettuce, sweet potato, yuca potato, cabbage, eggplant, papaya trees, mango, and cassava. The process of increasing in size and diversification of vegetables grown was led entirely by the local community. In connection with this, the local community started to harvest and began to sell the vegetable products at the local market. At the meat goat workshops, local participants rescued a local knowledge by describing and practicing a traditional way to process goat meat by drying it outdoors and then doing a smoked treatment. This information might contribute to describe the level of empowerment of this community, and thus give evidence of acceptance of foreign intervention for improving their own proceedings and traditions.

Keywords: children malnutrition, food security, Local community, participatory approach

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Authors: Kishor Chandra Kandpal, Amit Kumar

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The Indian Himalaya region harbours approximately 1748 plants of medicinal importance, and as per International Union for Conservation of Nature (IUCN), the 112 plant species among these are threatened and endangered. To ease the pressure on these plants, the government of India is encouraging its in-situ cultivation. The Saussurea costus, Valeriana jatamansi, and Picrorhiza kurroa have also been prioritized for large scale cultivation owing to their market demand, conservation value and medicinal properties. These species are found from 1000 m to 4000 m elevation ranges in the Indian Himalaya. Identification of these plants in the field requires taxonomic skills, which is one of the major bottleneck in the conservation and management of these plants. In recent years, Hyperspectral remote sensing techniques have been precisely used for the discrimination of plant species with the help of their unique spectral signatures. In this background, a spectral library of the above 03 medicinal plants was prepared by collecting the spectral data using a handheld spectroradiometer (325 to 1075 nm) from farmer’s fields of Himachal Pradesh and Uttarakhand states of Indian Himalaya. The Random forest (RF) model was implied on the spectral data for the classification of the medicinal plants. The 80:20 standard split ratio was followed for training and validation of the RF model, which resulted in training accuracy of 84.39 % (kappa coefficient = 0.72) and testing accuracy of 85.29 % (kappa coefficient = 0.77). This RF classifier has identified green (555 to 598 nm), red (605 nm), and near-infrared (725 to 840 nm) wavelength regions suitable for the discrimination of these species. The findings of this study have provided a technique for rapid and onsite identification of the above medicinal plants in the field. This will also be a key input for the classification of hyperspectral remote sensing images for mapping of these species in farmer’s field on a regional scale. This is a pioneer study in the Indian Himalaya region for medicinal plants in which the applicability of hyperspectral remote sensing has been explored.

Keywords: himalaya, hyperspectral remote sensing, machine learning; medicinal plants, random forests

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Authors: Majid Aldalbahi

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In 2009, over 3.4 billion people in the world resided in urban areas as a result of rapid urban growth. This figure is estimated to increase to 6.5 billion by 2050. This urban growth phenomenon has raised challenges for many countries in both the developing and developed worlds. Urban growth is a complicated process involving the spatiotemporal changes of all socio-economic and physical components at different scales. The socio-economic components of urban growth are related to urban population growth and economic growth, while physical components of urban growth and economic growth are related to spatial expansion, land cover change and land use change which are the focus of this research. The interactions between these components are complex and no-linear. Several factors and forces cause these complex interactions including transportation and communication, internal and international migrations, public policies, high natural growth rates of urban populations and public policies. Urban growth has positive and negative consequences. The positive effects relates to planned and orderly urban growth, while negative effects relate to unplanned and scattered growth, which is called sprawl. Although urban growth is considered as necessary for sustainable urbanization, uncontrolled and rapid growth cause various problems including consumption of precious rural land resources at urban fringe, landscape alteration, traffic congestion, infrastructure pressure, and neighborhood conflicts. Traditional urban planning approaches in fast growing cities cannot accommodate the negative consequences of rapid urban growth. Microsimulation programme, and modelling techniques are effective means to provide new urban development, management and planning methods and approaches. This paper aims to use these techniques to understand and analyse the complex interactions for the case study of Riyadh city, a fast growing city in Saudi Arabia.

Keywords: policy implications, urban planning, traffic congestion, urban growth, Suadi Arabia, Riyadh

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Authors: Long Long Chen, Xinwei Liao, Shanfa Tang, Shaojing Jiang, Ruijia Tang, Rui Wang, Shu Yun Feng, Si Yao Wang

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Unconventional oil reservoirs have the characteristics of strong heterogeneity and poor injectability, and traditional chemical flooding technology is not effective in such reservoirs; polymer flooding in the production of heavy oil reservoirs is difficult to handle produced fluid and easy to block oil wells, etc. Therefore, a viscoelastic fluid flooding system with good adaptability, low interfacial tension, plugging, and diverting capabilities was studied. The viscosity, viscoelasticity, surface/interfacial activity, wettability, emulsification, and oil displacement performance of the anionic Gemini surfactant flooding system were studied, and the adaptability of the system to the reservoir environment was evaluated. The oil displacement effect of the system in low-permeability and high-permeability (heavy oil) reservoirs was investigated, and the mechanism of the system to enhance water flooding recovery was discussed. The results show that the system has temperature resistance and viscosity increasing performance (65℃, 4.12mPa•s), shear resistance and viscoelasticity; at a lower concentration (0.5%), the oil-water interfacial tension can be reduced to ultra-low (10-3mN/m); has good emulsifying ability for heavy oil, and is easy to break demulsification (4.5min); has good adaptability to reservoirs with high salinity (30000mg/L). Oil flooding experiments show that this system can increase the water flooding recovery rate of low-permeability homogeneous and heterogeneous cores by 13% and 15%, respectively, and can increase the water-flooding recovery rate of high-permeability heavy oil reservoirs by 40%. The anionic Gemini surfactant flooding system studied in this paper is a viscoelastic fluid, has good emulsifying and oil washing ability, can effectively improve sweep efficiency, reduce injection pressure, and has broad application in unconventional reservoirs to enhance oil recovery prospect.

Keywords: oil displacement system, recovery factor, rheology, interfacial activity, environmental adaptability

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Authors: Devendra Gupta, S. P. Ambesh, P. K Singh

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Introduction: Minimally invasive coronary artery bypass grafting (MICABG) is a less invasive method of performing surgical revascularization. Minimally invasive direct coronary artery bypass (MIDCAB) provides many anesthetic challenges including one lung ventilation (OLV), managing myocardial ischemia, and pain. We present an early and midterm result of the use of this technique with OLV. Method: We enrolled 62 patients for analysis operated between 2008 and 2012. Patients were anesthetized and left endobronchial tube was placed. During the procedure left lung was isolated and one lung ventilation was maintained through right lung. Operation was performed utilizing off pump technique of coronary artery bypass grafting through a minimal invasive incision. Left internal mammary artery graft was done for single vessel disease and radial artery was utilized for other grafts if required. Postoperative ventilation was done with single lumen endotracheal tube. Median follow-up is 2.5 years (6 months to 4 years). Results: Median age was 58.5 years (41-77) and all were male. Single vessel disease was present in 36, double vessel in 24 and triple vessel disease in 2 patients. All the patients had normal left ventricular size and function. In 2 cases difficulty were encounter in placement of endobronchial tube. In 1 case cuff of endobronchial tube was ruptured during intubation. High airway pressure was developed on OLV in 1 case and surgery was accomplished with two lung anesthesia with low tidal volume. Mean postoperative ventilation time was 14.4 hour (11-22). There was no perioperative and 30 day mortality. Conversion to median sternotomy to complete the operation was done in 3.23% (2 out of 62 patients). One patient had acute myocardial infarction postoperatively and there were no deaths during follow-up. Conclusion: MICABG is a safe and effective method of revascularization with OLV in low risk candidates for coronary artery bypass grafting.

Keywords: MIDCABG, one lung ventilation, coronary artery bypass grafting, endobronchial tube

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Authors: Dammar Bahadur Adhikari

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Community forestry in Nepal has got disproportionately high level of support from government and other actors in forestry sector. Even though master plan for forestry sector (1989) has highlighted community and private forestry as one component, the government policies and other intervention deliberately left out private forestry in its structure and programs. The study aimed at providing the pathway for formulating appropriate policies to address need of different kind of forest management regimes in Rautahat district, Nepal. The key areas the research focused were assessment of current status of private forestry, community forest users' understanding on private forestry; criteria for choosing species of private forestry and factors affecting establishment of private forestry in the area. Qualitative and quantitative data were collected employing questionnaire survey, rapid forest assessment and key informant interview. The study found out that forest policies are imposed due to intense pressure of exogenous forces than due to endogenous demand. Most of the local people opine that their traditional knowledge and skills are not sufficient for private forestry and hence need training on the matter. Likewise, local use, market value and rotation dictate the choice of species for plantation in private forests. Currently district forest office is the only government institution working in the area of private forestry all other governmental and non-governmental organizations have condoned. private forestry. Similarly, only permanent settlers in the area are found to establish private forests other forest users such as migrants and forest encroachers follow opportunistic behavior to meet their forest product need from community and national forests. In this regard, the study recommends taking appropriate step to support other forest management system including private forestry provide community forestry the benefits of competition as suggested by Darwin in 18th century, one and half century back and to help alleviate poverty by channelizing benefits to household level.

Keywords: community forest, forest management, poverty, private forest, users’ group

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Authors: C. Lanzerstorfer, M. Hinterberger

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The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. Subsequently, physical separation processes are applied to concentrate the iron ore. The fine-grained ore concentrates produced need to be transported, stored, and processed. For smooth operation of these processes, the flow properties of the material are crucial. The flowability of powders depends on several properties of the material: grain size, grain size distribution, grain shape, and moisture content of the material. The flowability of powders can be measured using ring shear testers. In this study, the influence of the moisture content on the flowability for the Krivoy Rog magnetite iron ore concentrate was investigated. Dry iron ore concentrate was mixed with varying amounts of water to produce samples with a moisture content in the range of 0.2 to 12.2%. The flowability of the samples was investigated using a Schulze ring shear tester. At all measured values of the normal stress (1.0 kPa – 20 kPa), the flowability decreased significantly from dry ore to a moisture content of approximately 3-5%. At higher moisture contents, the flowability was nearly constant, while at the maximum moisture content the flowability improved for high values of the normal stress only. The results also showed an improving flowability with increasing consolidation stress for all moisture content levels investigated. The wall friction angle of the dust with carbon steel (S235JR), and an ultra-high molecule low-pressure polyethylene (Robalon) was also investigated. The wall friction angle increased significantly from dry ore to a moisture content of approximately 3%. For higher moisture content levels, the wall friction angles were nearly constant. Generally, the wall friction angle was approximately 4° lower at the higher wall normal stress.

Keywords: iron ore concentrate, flowability, moisture content, wall friction angle

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Authors: Asad Hanif, Pavithra Parthasarathy, Zongjin Li

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Thermal insulating composites help to reduce the total power consumption in a building by creating a barrier between external and internal environment. Such composites can be used in the roofing tiles or wall panels for exterior surfaces. This study purposes to develop lightweight cement-based composites for thermal insulating applications. Waste materials like silica fume (an industrial by-product) and fly ash cenosphere (FAC) (hollow micro-spherical shells obtained as a waste residue from coal fired power plants) were used as partial replacement of cement and lightweight filler, respectively. Moreover, aerogel, a nano-porous material made of silica, was also used in different dosages for improved thermal insulating behavior, while poly vinyl alcohol (PVA) fibers were added for enhanced toughness. The raw materials including binders and fillers were characterized by X-Ray Diffraction (XRD), X-Ray Fluorescence spectroscopy (XRF), and Brunauer–Emmett–Teller (BET) analysis techniques in which various physical and chemical properties of the raw materials were evaluated like specific surface area, chemical composition (oxide form), and pore size distribution (if any). Ultra-lightweight cementitious composites were developed by varying the amounts of FAC and aerogel with 28-day unit weight ranging from 1551.28 kg/m³ to 1027.85 kg/m³. Excellent mechanical and thermal insulating properties of the resulting composites were obtained ranging from 53.62 MPa to 8.66 MPa compressive strength, 9.77 MPa to 3.98 MPa flexural strength, and 0.3025 W/m-K to 0.2009 W/m-K as thermal conductivity coefficient (QTM-500). The composites were also tested for peak temperature difference between outer and inner surfaces when subjected to heating (in a specially designed experimental set-up) by a 275W infrared lamp. The temperature difference up to 16.78 ^oC was achieved, which indicated outstanding properties of the developed composites to act as a thermal barrier for building envelopes. Microstructural studies were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) for characterizing the inner structure of the composite specimen. Also, the hydration products were quantified using the surface area mapping and line scale technique in EDS. The microstructural analyses indicated excellent bonding of FAC and aerogel in the cementitious system. Also, selective reactivity of FAC was ascertained from the SEM imagery where the partially consumed FAC shells were observed. All in all, the lightweight fillers, FAC, and aerogel helped to produce the lightweight composites due to their physical characteristics, while exceptional mechanical properties, owing to FAC partial reactivity, were achieved.

Keywords: aerogel, cement-based, composite, fly ash cenosphere, lightweight, sustainable development, thermal conductivity

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Authors: Leo Laine, Morgan Johansson

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To meet the civilizations future needs for safe living and low environmental footprint, the engineers designing the complex systems of tomorrow will need efficient ways to model and optimize these systems for their intended purpose. For example, a civil defence shelter and its subsystem components needs to withstand, e.g. airblast and ground shock from decided design level explosion which detonates with a certain distance from the structure. In addition, the complex civil defence shelter needs to have functioning air filter systems to protect from toxic gases and provide clean air, clean water, heat, and electricity needs to also be available through shock and vibration safe fixtures and connections. Similar complex building systems can be found in any concentrated living or office area. In this paper, the authors use a multidomain modelling language called Modelica to model a concrete wall as a single degree of freedom (SDOF) system with elastoplastic properties with the implemented option of plastic hardening. The elastoplastic model was developed and implemented in the open source tool OpenModelica. The simulation model was tested on the case with a transient equivalent reflected pressure time history representing an airblast from 100 kg TNT detonating 15 meters from the wall. The concrete wall is approximately regarded as a concrete strip of 1.0 m width. This load represents a realistic threat on any building in a city like area. The OpenModelica model results were compared with an Excel implementation of a SDOF model with an elastic-plastic spring using simple fixed timestep central difference solver. The structural displacement results agreed very well with each other when it comes to plastic displacement magnitude, elastic oscillation displacement, and response times.

Keywords: airblast from explosives, elastoplastic spring model, Modelica modelling language, SDOF, structural response of concrete structure

Procedia PDF Downloads 125