Search results for: power spectral density.
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 9915

Search results for: power spectral density.

2475 Passport Bros: Exploring Neocolonial Masculinity and Sex Tourism as a Response to Shifting Gender Dynamics

Authors: Kellen Sharp

Abstract:

This study explores the phenomenon of ‘Passport Bros’, a subset within the manosphere responding to perceived crises in masculinity amidst changing gender dynamics. Focusing on a computational analysis of the passport bro community, the research addresses normative beliefs, deviations from MGTOW ideology, and discussions on nationality, race, and gender. Originating from the MGTOW movement, passport bros engage in a neocolonial approach by seeking traditional, non-Western women, attributing this pursuit to dissatisfaction with modern Western women. The paper examines how hetero pessimism within MGTOW shapes the emergence of passport bros, leading to the adoption of red pill ideologies and ultimately manifesting in the form of sex tourism. Analyzing data collected from passport bro forums through computer-assisted content analysis, the study identifies key discourses such as questions and answers, money, attitudes towards Western and traditional women, and discussions about the movement itself. The findings highlight the nuanced intersection of gender, race, and global power dynamics within the passport bro community, shedding light on their motivations and impact on neocolonial legacies.

Keywords: toxic online community, manosphere, gender and media, neocolonialism

Procedia PDF Downloads 75
2474 Causal Estimation for the Left-Truncation Adjusted Time-Varying Covariates under the Semiparametric Transformation Models of a Survival Time

Authors: Yemane Hailu Fissuh, Zhongzhan Zhang

Abstract:

In biomedical researches and randomized clinical trials, the most commonly interested outcomes are time-to-event so-called survival data. The importance of robust models in this context is to compare the effect of randomly controlled experimental groups that have a sense of causality. Causal estimation is the scientific concept of comparing the pragmatic effect of treatments conditional to the given covariates rather than assessing the simple association of response and predictors. Hence, the causal effect based semiparametric transformation model was proposed to estimate the effect of treatment with the presence of possibly time-varying covariates. Due to its high flexibility and robustness, the semiparametric transformation model which shall be applied in this paper has been given much more attention for estimation of a causal effect in modeling left-truncated and right censored survival data. Despite its wide applications and popularity in estimating unknown parameters, the maximum likelihood estimation technique is quite complex and burdensome in estimating unknown parameters and unspecified transformation function in the presence of possibly time-varying covariates. Thus, to ease the complexity we proposed the modified estimating equations. After intuitive estimation procedures, the consistency and asymptotic properties of the estimators were derived and the characteristics of the estimators in the finite sample performance of the proposed model were illustrated via simulation studies and Stanford heart transplant real data example. To sum up the study, the bias of covariates was adjusted via estimating the density function for truncation variable which was also incorporated in the model as a covariate in order to relax the independence assumption of failure time and truncation time. Moreover, the expectation-maximization (EM) algorithm was described for the estimation of iterative unknown parameters and unspecified transformation function. In addition, the causal effect was derived by the ratio of the cumulative hazard function of active and passive experiments after adjusting for bias raised in the model due to the truncation variable.

Keywords: causal estimation, EM algorithm, semiparametric transformation models, time-to-event outcomes, time-varying covariate

Procedia PDF Downloads 125
2473 Physiological Responses of Dominant Grassland Species to Different Grazing Intensity in Inner Mongolia, China

Authors: Min Liu, Jirui Gong, Qinpu Luo, Lili Yang, Bo Yang, Zihe Zhang, Yan Pan, Zhanwei Zhai

Abstract:

Grazing disturbance is one of the important land-use types that affect plant growth and ecosystem processes. In order to study the responses of dominant species to grazing in the semiarid temperate grassland of Inner Mongolia, we set five grazing intensity plots: a control and four levels of grazing (light (LG), moderate (MG), heavy (HG) and extreme heavy grazing (EHG)) to test the morphological and physiological responses of Stipa grandis, Leymus chinensis at the individual levels. With the increase of grazing intensity, Stipa grandis and Leymus chinensis both exhibited reduced plant height, leaf area, stem length and aboveground biomass, showing a significant dwarf phenomenon especially in HG and EHG plots. The photosynthetic capacity decreased along the grazing gradient. Especially in the MG plot, the two dominant species have lowest net photosynthetic rate (Pn) and water use efficiency (WUE). However, in the HG and EHG plots, the two species had high light saturation point (LSP) and low light compensation point (LCP), indicating they have high light-use efficiency. They showed a stimulation of compensatory photosynthesis to the remnant leaves as compared with grasses in MG plot. For Leymus chinensis, the lipid peroxidation level did not increase with the low malondialdehyde (MDA) content even in the EHG plot. It may be due to the high enzymes activity of superoxide dismutase (SOD) and peroxidase (POD) to reduce the damage of reactive oxygen species. Meanwhile, more carbohydrate was stored in the leaf of Leymus chinensis to provide energy to the plant regrowth. On the contrary, Stipa grandis showed the high level of lipid peroxidation especially in the HG and EHG plots with decreased antioxidant enzymes activity. The soluble protein content did not change significantly in the different plots. Therefore, with the increase of grazing intensity, plants changed morphological and physiological traits to defend themselves effectively to herbivores. Leymus chinensis is more resistant to grazing than Stipa grandis in terms of tolerance traits, particularly under heavy grazing pressure.

Keywords: antioxidant enzymes activity, grazing density, morphological responses, photosynthesis

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2472 Tokenization of Blue Bonds to Scale Blue Carbon Projects

Authors: Rodrigo Buaiz Boabaid

Abstract:

Tokenization of Blue Bonds is an emerging Green Finance tool that has the potential to scale Blue Carbon Projects to fight climate change. This innovative solution has a huge potential to democratize the green finance market and catalyze innovations in the climate change finance sector. Switzerland has emerged as a leader in the Green Finance space and is well-positioned to drive the adoption of Tokenization of Blue & Green Bonds. This unique approach has the potential to unlock new sources of capital and enable global investors to participate in the financing of sustainable blue carbon projects. By leveraging the power of blockchain technology, Tokenization of Blue Bonds can provide greater transparency, efficiency, and security in the investment process while also reducing transaction costs. Investments are in line with the highest regulations and designed according to the stringent legal framework and compliance standards set by Switzerland. The potential benefits of Tokenization of Blue Bonds are significant and could transform the way that sustainable projects are financed. By unlocking new sources of capital, this approach has the potential to accelerate the deployment of Blue Carbon projects and create new opportunities for investors to participate in the fight against climate change.

Keywords: blue bonds, blue carbon, tokenization, green finance

Procedia PDF Downloads 87
2471 Computational Approach to Cyclin-Dependent Kinase 2 Inhibitors Design and Analysis: Merging Quantitative Structure-Activity Relationship, Absorption, Distribution, Metabolism, Excretion, and Toxicity, Molecular Docking, and Molecular Dynamics Simulations

Authors: Mohamed Moussaoui, Mouna Baassi, Soukayna Baammi, Hatim Soufi, Mohammed Salah, Rachid Daoud, Achraf EL Allali, Mohammed Elalaoui Belghiti, Said Belaaouad

Abstract:

The present study aims to investigate the quantitative structure-activity relationship (QSAR) of a series of Thiazole derivatives reported as anticancer agents (hepatocellular carcinoma), using principally the electronic descriptors calculated by the density functional theory (DFT) method and by applying the multiple linear regression method. The developed model showed good statistical parameters (R²= 0.725, R²ₐ𝒹ⱼ= 0.653, MSE = 0.060, R²ₜₑₛₜ= 0.827, Q²𝒸ᵥ = 0.536). The energy of the highest occupied molecular orbital (EHOMO) orbital, electronic energy (TE), shape coefficient (I), number of rotatable bonds (NROT), and index of refraction (n) were revealed to be the main descriptors influencing the anti-cancer activity. Additional Thiazole derivatives were then designed and their activities and pharmacokinetic properties were predicted using the validated QSAR model. These designed molecules underwent evaluation through molecular docking (MD) and molecular dynamic (MD) simulations, with binding affinity calculated using the MMPBSA script according to a 100 ns simulation trajectory. This process aimed to study both their affinity and stability towards Cyclin-Dependent Kinase 2 (CDK2), a target protein for cancer disease treatment. The research concluded by identifying four CDK2 inhibitors - A1, A3, A5, and A6 - displaying satisfactory pharmacokinetic properties. MDs results indicated that the designed compound A5 remained stable in the active center of the CDK2 protein, suggesting its potential as an effective inhibitor for the treatment of hepatocellular carcinoma. The findings of this study could contribute significantly to the development of effective CDK2 inhibitors.

Keywords: QSAR, ADMET, Thiazole, anticancer, molecular docking, molecular dynamic simulations, MMPBSA calculation

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2470 Optimization of Laser Doping Selective Emitter for Silicon Solar Cells

Authors: Meziani Samir, Moussi Abderrahmane, Chaouchi Sofiane, Guendouzi Awatif, Djema Oussama

Abstract:

Laser doping has a large potential for integration into silicon solar cell technologies. The ability to process local, heavily diffused regions in a self-aligned manner can greatly simplify processing sequences for the fabrication of selective emitter. The choice of laser parameters for a laser doping process with 532nm is investigated. Solid state lasers with different power and speed were used for laser doping. In this work, the aim is the formation of selective emitter solar cells with a reduced number of technological steps. In order to have a highly doped localized emitter region, we used a 532 nm laser doping. Note that this region will receive the metallization of the Ag grid by screen printing. For this, we use SOLIDWORKS software to design a single type of pattern for square silicon cells. Sheet resistances, phosphorus doping concentration and silicon bulk lifetimes of irradiated samples are presented. Additionally, secondary ion mass spectroscopy (SIMS) profiles of the laser processed samples were acquired. Scanning electron microscope and optical microscope images of laser processed surfaces at different parameters are shown and compared.

Keywords: laser doping, selective emitter, silicon, solar cells

Procedia PDF Downloads 102
2469 A Simulation-Based Study of Dust Ingression into Microphone of Indoor Consumer Electronic Devices

Authors: Zhichao Song, Swanand Vaidya

Abstract:

Nowadays, most portable (e.g., smartphones) and wearable (e.g., smartwatches and earphones) consumer hardware are designed to be dustproof following IP5 or IP6 ratings to ensure the product is able to handle potentially dusty outdoor environments. On the other hand, the design guideline is relatively vague for indoor devices (e.g., smart displays and speakers). While it is generally believed that the indoor environment is much less dusty, in certain circumstances, dust ingression is still able to cause functional failures, such as microphone frequency response shift and camera black spot, or cosmetic dissatisfaction, mainly the dust build up in visible pockets and gaps which is hard to clean. In this paper, we developed a simulation methodology to analyze dust settlement and ingression into known ports of a device. A closed system is initialized with dust particles whose sizes follow Weibull distribution based on data collected in a user study, and dust particle movement was approximated as a settlement in stationary fluid, which is governed by Stokes’ law. Following this method, we simulated dust ingression into MEMS microphone through the acoustic port and protective mesh. Various design and environmental parameters are evaluated including mesh pore size, acoustic port depth-to-diameter ratio, mass density of dust material and inclined angle of microphone port. Although the dependencies of dust resistance on these parameters are all monotonic, smaller mesh pore size, larger acoustic depth-to-opening ratio and more inclined microphone placement (towards horizontal direction) are preferred for dust resistance; these preferences may represent certain trade-offs in audio performance and compromise in industrial design. The simulation results suggest the quantitative ranges of these parameters, with more pronounced effects in the improvement of dust resistance. Based on the simulation results, we proposed several design guidelines that intend to achieve an overall balanced design from audio performance, dust resistance, and flexibility in industrial design.

Keywords: dust settlement, numerical simulation, microphone design, Weibull distribution, Stoke's equation

Procedia PDF Downloads 107
2468 The Social Media, Reading Culture and Vocabulary Expansion: Three Universities from Northern Nigeria

Authors: Nasir Umar Abdullahi

Abstract:

The social media profoundly causes the reading culture to decline in Nigeria, where the English language is a second language (SL), a language of instruction (LI), as well as the target language (TL). This is because the university students have, over the years, failed to make extensive reading their closest companion, with much emphasis on reading the European novels, newspapers, magazines, etc., so as to learn language from its original or native speakers for linguistic competence. Instead, they squander the most part of their day and nocturnal hours, sending and receiving messages through social media. The end result is their vocabulary become stagnant or ebbs, and that they cannot acquire the Cox head’s 570 vocabulary, let alone the Nation’s 2000 vocabulary to use the language fluently in writing, reading, listening, and speaking and to further compete with the native speaker in varying degrees of language usages. Be that as it may, if the social media is a monster in worsening the decline in reading culture, which degenerates in the Northern part of the country in contradistinction to the Southern part, it boosts it as well, for aside the social media language, slangs, cliché, for instance, students improve their vocabulary power, and at the same time it allows the students to privately and leisurely put the language into use, by using practically some of the vocabulary they have acquired to chart, to comment, socialize to adjudge, etc. This is what this paper tries to explore in Umaru Musa Yar’adua University Al-qalam University and the Federal University Dutin-ma.

Keywords: social media, reading, vocabulary, universities

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2467 The Power of Local People in Sustainable Tourism Management: A Case Study of Community Participation on Illuminated Boat Procession in Thailand

Authors: Prompassorn Chunhabunyatip

Abstract:

The objectives of this research were to study the factors affecting the participation of local people and the obstacles and recommendations towards local people’s participation in illuminated boat procession culture. The study looked at both qualitative, and quantitative data were collected by in-depth interview and analyzed by the descriptive approach. The 296 samplings were a local community who participated in constructing the illuminated boat in each community for 14 communities. The results of this study showed that the factor that encourages local people’s participation in illuminated both procession is the awareness of an importance of cultural uniqueness in the local. The problems and obstacles to the participation in illuminated boat procession include the resources for constructing illuminated both such as bamboos are run out of and price increasing, lack of proper cooperation between local people and government officers and conflict in interests between in local government office. So, the result of this study recommended that the government officers should be taken into account about community participation in the illuminated boat procession culture because without local people, the uniqueness culture of Nakhon Phanom Province would not exist and they would not reach the sustainable tourism goal.

Keywords: illuminated both culture, community participation, sustainable tourism management, Nakhon Phanom province

Procedia PDF Downloads 359
2466 To Be Freed from Conformists for Better Shared Leadership

Authors: Lyne Chantal Boudreau, Claudine Auger, Arline Laforest

Abstract:

In order to meet the challenges of learning in a minority Francophone environment, three organizers created a space where a group of stakeholders from the school system and from the post-secondary and community sectors could contribute to reflections on specific educational topics by sharing winning practices. The success of this provincial congress rest on shared leadership which was intuitively used by the organizers who planned and conducted both editions. This leadership style requires leaders to transition from a hierarchical to a horizontal approach, that is, to an approach where each individual is at the same level. In this exploratory research, it has been demonstrated that this shared leadership’s success depends on the capacity of the leaders to free themselves from conformists who are found at all levels of the education system. This ability best fosters the mobilization of all education stakeholders in advancing in-depth knowledge in a particular field while simultaneously creating a sense of collective efficacy among these partners and developing the learners’ full potential. This session will present ways in which it is possible to be freed from conformists through knowing how to recognize conformism, through taking risks and through opening genuine discussions. Shared leadership revolves around a collective power derived from the leadership of each and everyone in a space where all are rallied to promote the ultimate advancement of society.

Keywords: conformists, education, minority context, shared leadership

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2465 Use of Soil Microorganisms for the Production of Electricity through Microbial Fuel Cells

Authors: Abhipsa Mohanty, Harit Jha

Abstract:

The world's energy demands are continuing to rise, resulting in a worldwide energy crisis and environmental pollution. Because of finite, declining supply and environmental damage, reliance on fossil fuels is unsustainable. As a result, experts are concentrating on alternative, renewable, and carbon-free energy sources. Energy sources that are both environmentally and economically sustainable are required. Microbial fuel cells (MFCs) have recently received a lot of attention due to their low operating temperatures and ability to use a variety of biodegradable substrates as fuel. There are single-chamber MFCs as well as traditional MFCs with anode and cathode compartments. Bioelectricity is produced when microorganisms actively catabolize substrate. MFCs can be used as a power source in small devices like biosensors. Understanding of its components, microbiological processes, limiting variables, and construction designs in MFC systems must be simplified, and large-scale systems must be developed for them to be cost-effective as well as increase electricity production. The purpose of this research was to review current microbiology knowledge in the field of electricity. The manufacturing process, the materials, and procedures utilized to construct the technology, as well as the applications of MFC technology, are all covered.

Keywords: bio-electricity, exoelectrogenic bacteria, microbial fuel cells, soil microorganisms

Procedia PDF Downloads 93
2464 Food Losses Reducing by Extending the Minimum Durability Date of Thermally Processed Products

Authors: Dorota Zielińska, Monika Trząskowska, Anna Łepecka, Katarzyna Neffe-Skocińska, Beata Bilska, Marzena Tomaszewska, Danuta Kołożyn-Krajewska

Abstract:

Minimum durability date (MDD) labeled food is known to have a long shelf life. A properly stored or transported food retains its physical, chemical, microbiological, and sensory properties up to MDD. The aim of the study was to assess the sensory quality and microbiological safety of selected thermally processed products,i.e., mayonnaise, jam, and canned tuna within and after MDD. The scope of the study was to determine the markers of microbiological quality, i.e., the total viable count (TVC), the Enterobacteriaceae count and the total yeast and mold (TYMC) count on the last day of MDD and after 1 and 3 months of storage, after the MDD expired. In addition, the presence of Salmonella and Listeria monocytogenes was examined on the last day of MDD. The sensory quality of products was assessed by quantitative descriptive analysis (QDA), the intensity of differentiators (quality features), and overall quality were defined and determined. It was found that during three months storage of tested food products, after the MDD expired, the microbiological quality slightly decreased, however, regardless of the tested sample, TVC was at the level of <3 log cfu/g, similarly, the Enterobacretiaceae, what indicates the good microbiological quality of the tested foods. The TYMC increased during storage but did not exceed 2 logs cfu/g of product. Salmonella and Listeria monocytogenes were not found in any of the tested food samples. The sensory quality of mayonnaise negatively changed during storage. After three months from the expiry of MDD, a decrease in the "fat" and "egg" taste and aroma intensity, as well as the "density" were found. The "sour" taste intensity of blueberry jam after three months of storage was slightly higher, compared to the jam tested on the last day of MDD, without affecting the overall quality. In the case of tuna samples, an increase in the "fishy" taste and aroma intensity was observed during storage, and the overall quality did not change. Tested thermally processed products (mayonnaise, jam, and canned tuna) were characterized by good microbiological and sensory quality on the last day of MDD, as well as after three months of storage under conditions recommended by the producer. These findings indicate the possibility of reducing food losses by extending or completely abolishing the MDD of selected thermal processed food products.

Keywords: food wastes, food quality and safety, mayonnaise, jam, tuna

Procedia PDF Downloads 129
2463 Intelligent Platform for Photovoltaic Park Operation and Maintenance

Authors: Andreas Livera, Spyros Theocharides, Michalis Florides, Charalambos Anastassiou

Abstract:

A main challenge in the quest for ensuring quality of operation, especially for photovoltaic (PV) systems, is to safeguard the reliability and optimal performance by detecting and diagnosing potential failures and performance losses at early stages or before the occurrence through real-time monitoring, supervision, fault detection, and predictive maintenance. The purpose of this work is to present the functionalities and results related to the development and validation of a software platform for PV assets diagnosis and maintenance. The platform brings together proprietary hardware sensors and software algorithms to enable the early detection and prediction of the most common and critical faults in PV systems. It was validated using field measurements from operating PV systems. The results showed the effectiveness of the platform for detecting faults and losses (e.g., inverter failures, string disconnections, and potential induced degradation) at early stages, forecasting PV power production while also providing recommendations for maintenance actions. Increased PV energy yield production and revenue can be thus achieved while also minimizing operation and maintenance (O&M) costs.

Keywords: failure detection and prediction, operation and maintenance, performance monitoring, photovoltaic, platform, recommendations, predictive maintenance

Procedia PDF Downloads 49
2462 The Influence of Wasta on Employees and Organizations in Kuwait

Authors: Abrar Al-Enzi

Abstract:

This study investigates the role of the popular utilization of Wasta within Arab societies. Wasta, by definition, is a set of personal networks based on family or kinship ties in which power and influence are utilized to get things done. As Wasta evolved, it became intensely rooted in Arab cultures, which is considered as an intrinsic tool of the culture, a method of doing business transactions and as a family obligation. However, the consequences related to Wasta in business are substantial as it impacts organizational performance, employee’s perception of the organization and the atmosphere between employees. To date, there has been little in-depth organizational research on the impact of Wasta. Hence, the question that will be addressed is: Does Wasta influence human resource management, knowledge sharing and innovation in Kuwait, which in turn affects employees’ commitment within organizations? As a result, a mixed method sequential exploratory research design will be used to examine the mentioned subject, which consists of three phases: (1) Doing some initial exploratory interviews; (2) Developing a paper-based and online survey (Quantitative method) based on the findings; (3) Lastly, following up with semi-structured interviews (Qualitative method). The rationale behind this approach is that both qualitative and quantitative methods complement each other by providing a more complete picture of the subject matter.

Keywords: commitment, HRM practices, social capital, Wasta

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2461 Factors Influencing Prevalence of HIV/AIDS Among Men Who Have Sex With men (MSM) Aged 18-24 years in Mtwapa Town, Kilifi County, Kenya

Authors: Oscar Maina Irungu

Abstract:

Background: Men who have sex with men (MSM) in Mtwapa Town, Kilifi County are at high risk of HIV infection. Probability sample surveys to determine HIV prevalence among MSM in Mtwapa are needed to inform prevention and care services. Methods: In 2013, a cross-sectional survey was conducted among MSM aged 18-24 years old, using respondent-driven sampling (RDS) in Mtwapa. Consenting MSM were tested for HIV (fingerstick rapid test). Population-based prevalence and 95 % confidence intervals (CI) were estimated using RDS Analysis Tool (RDSAT). Results: Among 274 MSM, the median age was 20 years (IQR: 19-23 years). Fifty percent of MSM reported not selling sex, while 13.2 % reported sex work as their “main occupation”, and another 28.4 % reported selling sex in the past two months (but not as their main occupation).Overall HIV prevalence was 19.2 % (CI: 12.2-23.6%). HIV prevalence was higher among MSM who reported sex work as their main occupation (28.3%,CI: 12.1-42.3%) or selling sex in the past two months (26.6 %, CI: 17.2-35.7 %),than among MSM who did not sell sex (11.6%,CI: 7.0-18.1%). Conclusion: HIV prevalence among MSM were high than among Kilifi’s general population aged 15-64 years (8.8%; 2010 KAIS) and highest in male sex workers. Health programs need to address concerns and modify services to meet needs of diverse subgroups of MSM. We recommend continued, periodic surveillance to monitor HIV prevalence among MSM in Mtwapa, and expansion to other areas in Kenya.

Keywords: power point, Kenya, homosexuality, sex

Procedia PDF Downloads 382
2460 Identification of the Interior Noise Sources of Rail Vehicles

Authors: Hyo-In Koh, Anders Nordborg, Alex Sievi, Chun-Kwon Park

Abstract:

The noise source for the interior room of the high speed train is constituted by the rolling contact between the wheel and the rail, aerodynamic noise and structure-borne sound generated through the vibrations of bogie, connection points to the carbody. Air-borne sound is radiated through the panels and structures into the interior room of the trains. The high-speed lines are constructed with slab track systems and many tunnels. The interior noise level and the frequency characteristics vary according to types of the track structure and the infrastructure. In this paper the main sound sources and the transfer paths are studied to find out the contribution characteristics of the sources to the interior noise of a high-speed rail vehicle. For the identification of the acoustic power of each parts of the rolling noise sources a calculation model of wheel/rail noise is developed and used. For the analysis of the transmission of the sources to the interior noise noise and vibration are measured during the operation of the vehicle. According to operation speeds, the mainly contributed sources and the paths could be analyzed. Results of the calculations on the source generation and the results of the measurement with a high-speed train are shown and discussed.

Keywords: rail vehicle, high-speed, interior noise, noise source

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2459 Study on the Voltage Induced Wrinkling of Elastomer with Different Electrode Areas

Authors: Zhende Hou, Fan Yang, Guoli Zhang

Abstract:

Dielectric elastomer is a promising class of Electroactive polymers which can deform in response to an applied electric field. Comparing general smart material, the Dielectric elastomer is more compliance and can achieve higher energy density, which can be for diverse applications such as actuators, artificial muscles, soft robotics, and energy harvesters. The coupling of the Electroactive polymers and the electric field is that the elastomer is sandwiched between two compliant electrodes and when the electrodes are subjected to a voltage, the positive and negative charges on the two electrodes compress the polymer, so that the polymer reduces in thickness and expands in area. However, the pre-stretched dielectric elastomer film not only can achieve large electric-field induced deformation but also is prone to wrinkling, under the interaction of its own strain energy and the applied electric field energy. For a uniaxially pre-stretched dielectric elastomer film, the electrode area is an important parameter to the electric-field induced deformation and may also be a key factor affecting the film wrinkling. To determine and quantify the effect experimentally, VHB 9473 tapes were employed and compliant electrodes with different areas were pant on each of them. The tape was first tensed to a uniaxial stretch of 8. Then a DC voltage was applied to the electrodes and increased gradually until wrinkling occurred in the film. Then, the critical wrinkling voltages of the film with different electrode areas were obtained, and the wrinkle wavelengths were obtained simultaneously for analyzing the wrinkling characteristics. Experimental results indicate when the electrode area is smaller the wrinkling voltage is higher, and with the increases of electrode area, the wrinkling voltage decreases rapidly until a specific area. Beyond that, the wrinkling voltage becomes larger gradually with the increases of the area. While the wrinkle wavelength decreases gradually with the increase of voltage monotonically. That is, the relation between the critical wrinkling voltage and the electrode areas is U-shaped. Analysis believes that the film wrinkling is a kind of local effect, the interaction and the energy transfer between electrode region and non-electrode region have great influence on wrinkling. In the experiment, very thin copper wires are used as the electrode leads that just contact with the electrodes, which can avoid the stiffness of the leads affecting the wrinkling.

Keywords: elastomers, uniaxial stretch, electrode area, wrinkling

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2458 Using Sandplay Therapy to Assess Psychological Resilience

Authors: Dan Wang

Abstract:

Sandplay therapy is a Jungian psychological therapy developed by Dora Kalff in 1956. In sandplay therapy, the client first makes a sandtray with various miniatures and then has a communication with the therapist based on the sandtray. The special method makes sandplay therapy has great assessment potential. With regarding that the core treatment hypothesis of sandplay therapy - the self-healing power, is very similar to resilience. This study tries to use sandplay to evaluate psychological resilience. Participants are 107 undergraduates recruited from three public universities in China who were required to make an initial sandtray and to complete the Ego-Resiliency Scale (ER89) respectively. First, a 28- category General Sandtray Coding Manual (GSCM) was developed based on literature on sandplay therapy. Next, using GSCM to code the 107 initial sandtrays and conducted correlation analysis and regression analysis between all GSCM categories and ER89. Results show three categories (i.e., vitality, water types, and relationships) of sandplay account for 36.6% of the variance of ego-resilience and form the four-point Likert-type Sandtray Projective Test of Resilience (SPTR). Finally, it is found that SPTR dimensions and total score all have good inter-rater reliability, ranging from 0.89 to 0.93. This study provides an alternative approach to measure psychological resilience and can help to guide clinical social work.

Keywords: sandplay therapy, psychological resilience, measurement, college students

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2457 Political Implications of Shared Authority: Efforts to Retain Indigenous Sovereignty Within the Modern Global Power Structures

Authors: David E. Wilkins

Abstract:

While colonialism in its many guises remains the dominant theoretical framework within which to analyze Indigenous relations with state powers, this paper takes a deep look at the treaty, policy, and statutory efforts initiated by both Indigenous peoples and colonial, and later federal representatives within what is now the United States that were intended to create a Native constituent state of the union. While these plans ultimately failed, they are indicative of the reality that, throughout much of the shared Indigenous and American history, there were both Native and non-Native political elites who were keen on the idea of incorporating Indigenous peoples into the burgeoning body politic. This paper explores why these plans arose, who the architects were that devised them, which Native peoples were involved in, and why they ultimately failed to be enacted. Although governmental relations within the US remain fraught and unpredictable, Native nations continue to wield a form of sovereignty that, while truncated, has maintained their distinctive political statuses. There is much to be learned from the exploration of these mixed successes and failures. There are other examples across the globe whereby Indigenous peoples like the Saami and the Māori have secured greater clarity of their retained autonomy through structural political arrangements with the states that have laid claim to their territories while the Ainu struggle to regain their status.

Keywords: indigenous, sovereignty, diplomacy, intergovernmental

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2456 Anodic Stability of Li₆PS₅Cl/PEO Composite Polymer Electrolytes for All-Solid-State Lithium Batteries: A First-Principles Molecular Dynamics Study

Authors: Hao-Wen Chang, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang

Abstract:

All-solid-state lithium batteries (ASSLBs) are increasingly recognized as a safer and more reliable alternative to conventional lithium-ion batteries due to their non-flammable nature and enhanced safety performance. ASSLBs utilize a range of solid-state electrolytes, including solid polymer electrolytes (SPEs), inorganic solid electrolytes (ISEs), and composite polymer electrolytes (CPEs). SPEs are particularly valued for their flexibility, ease of processing, and excellent interfacial compatibility with electrodes, though their ionic conductivity remains a significant limitation. ISEs, on the other hand, provide high ionic conductivity, broad electrochemical windows, and strong mechanical properties but often face poor interfacial contact with electrodes, impeding performance. CPEs, which merge the strengths of SPEs and ISEs, represent a compelling solution for next-generation ASSLBs by addressing both electrochemical and mechanical challenges. Despite their potential, the mechanisms governing lithium-ion transport within these systems remain insufficiently understood. In this study, we designed CPEs based on argyrodite-type Li₆PS₅Cl (LPSC) combined with two distinct polymer matrices: poly(ethylene oxide) (PEO) with 24.5 wt% lithium bis(trifluoromethane)sulfonimide (LiTFSI) and polycaprolactone (PCL) with 25.7 wt% LiTFSI. Through density functional theory (DFT) calculations, we investigated the interfacial chemistry of these materials, revealing critical insights into their stability and interactions. Additionally, ab initio molecular dynamics (AIMD) simulations of lithium electrodes interfaced with LPSC layers containing polymers and LiTFSI demonstrated that the polymer matrix significantly mitigates LPSC decomposition, compared to systems with only a lithium electrode and LPSC layers. These findings underscore the pivotal role of CPEs in improving the performance and longevity of ASSLBs, offering a promising path forward for next-generation energy storage technologies.

Keywords: all-solid-state lithium-ion batteries, composite solid electrolytes, DFT calculations, Li-ion transport

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2455 Design of Reconfigurable and Non-reciprocal Metasurface with Independent Controls of Transmission Gain, Attenuation and Phase

Authors: Shi Yu Wang, Qian Wei Zhang, He Li, Hao Han He, Yun Bo Li

Abstract:

The spatial controls of electromagnetic (EM) waves have always been a research hot spot in recent years. And the rapid development of metasurface-based technologies has provided more freedoms for manipulating the EM waves. Here we propose the design of reconfigurable and non-reciprocal metasurface with independent controls of transmission gain, attenuation and phase. The proposed meta-atom mainly consists of the cascaded textures including the receiving antenna, the middle layer in which the power amplifiers (PAs), programmable attenuator and phase shifter locate, and the transmitting antenna. The programmable attenuator and phase shifter can realize the dynamic controls of transmission amplitude and phase independently, and the PA devices in the meta-atom can actualize the performance of non-reciprocal transmission. The proposed meta-atom is analyzed applying field-circuit co-simulation and a sample of the meta-atom is fabricated and measured under using two standard waveguides. The measured results verify the ability of the independent manipulation for transmission amplitude and phase of the proposed the meta-atom and the design method has been verified very well correspondingly.

Keywords: active circuits, independent controls of multiple electromagnetic features, non-reciprocal electromagnetic transmission, reconfigurable and programmable

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2454 In-situ Oxygen Enrichment for UCG

Authors: Adesola O. Orimoloye, Edward Gobina

Abstract:

Membrane separation technology is still considered as an emerging technology in the mining sector and does not yet have the widespread acceptance that it has in other industrial sectors. Underground Coal Gasification (UCG), wherein coal is converted to gas in-situ, is a safer alternative to mining method that retains all pollutants underground making the process environmentally friendly. In-situ combustion of coal for power generation allows access to more of the physical global coal resource than would be included in current economically recoverable reserve estimates. Where mining is no longer taking place, for economic or geological reasons, controlled gasification permits exploitation of the deposit (again a reaction of coal to form a synthesis gas) of coal seams in situ. The oxygen supply stage is one of the most expensive parts of any gasification project but the use of membranes is a potentially attractive approach for producing oxygen-enriched air. In this study, a variety of cost-effective membrane materials that gives an optimal amount of oxygen concentrations in the range of interest was designed and tested at diverse operating conditions. Oxygen-enriched atmosphere improves the combustion temperature but a decline is observed if oxygen concentration exceeds optimum. Experimental result also reveals the preparatory method, apparatus and performance of the fabricated membrane.

Keywords: membranes, oxygen-enrichment, gasification, coal

Procedia PDF Downloads 322
2453 Effect of Heavy Metals on the Life History Trait of Heterocephalobellus sp. and Cephalobus sp. (Nematode: Cephalobidae) Collected from a Small-Scale Mining Site, Davao de Oro, Philippines

Authors: Alissa Jane S. Mondejar, Florifern C. Paglinawan, Nanette Hope N. Sumaya, Joey Genevieve T. Martinez, Mylah Villacorte-Tabelin

Abstract:

Mining is associated with increased heavy metals in the environment, and heavy metal contamination disrupts the activities of soil fauna, such as nematodes, causing changes in the function of the soil ecosystem. Previous studies found that nematode community composition and diversity indices were strongly affected by heavy metals (e.g., Pb, Cu, and Zn). In this study, the influence of heavy metals on nematode survivability and reproduction were investigated. Life history analysis of the free-living nematodes, Heterocephalobellus sp. and Cephalobus sp. (Rhabditida: Cephalobidae) were assessed using the hanging drop technique, a technique often used in life history trait experiments. The nematodes were exposed to different temperatures, i.e.,20°C, 25°C, and 30°C, in different groups (control and heavy metal exposed) and fed with the same bacterial density of 1×109 Escherichia coli cells ml-1 for 30 days. Results showed that increasing temperature and exposure to heavy metals had a significant influence on the survivability and egg production of both species. Heterocephalobellus sp. and Cephalobus sp., when exposed to 20°C survived longer and produced few numbers of eggs but without subsequent hatching. Life history parameters of Heterocephalobellus sp. showed that the value of parameters was higher in the control group under net production rate (R0), fecundity (mx) which is also the same value for the total fertility rate (TFR), generation times (G0, G₁, and Gh) and Population doubling time (PDT). However, a lower rate of natural increase (rm) was observed since generation times were higher. Meanwhile, the life history parameters of Cephalobus sp. showed that the value of net production rate (R0) was higher in the exposed group. Fecundity (mx) which is also the same value for the TFR, G0, G1, Gh, and PDT, were higher in the control group. However, a lower rate of natural increase (rm) was observed since generation times were higher. In conclusion, temperature and exposure to heavy metals had a negative influence on the life history of the nematodes, however, further experiments should be considered.

Keywords: artisanal and small-scale gold mining (ASGM), hanging drop method, heavy metals, life history trait.

Procedia PDF Downloads 98
2452 Marketing of Global Business Systems Technologies as a Panacea to Unemployment Problem in Ogun State, Nigeria

Authors: Oluwatosin Oyewale

Abstract:

This research work seeks to take technology used for business systems as a product that requires marketing activities. Technology is invented and innovated upon in developed countries and are introduced into Africa through marketing activities. Businesses in Africa now adopt this technology for global competitiveness and hitherto unemployed but educationally advantaged people are trained in handling and utilising the technology. The aim of this study is to examine how marketing activities make this technology help in solving the unemployment problem in Africa. The areas of study are both the premier local government and the local government of the industrial haven in Ogun State, Nigeria. Area or cluster sampling technique was employed and Questionnaires were administered to two hundred respondents in the areas of study. Findings revealed that marketing has contributed to the promotion of technology; thereby making businesses globally competitive. In addition, technology has helped in reducing unemployment in developing countries. Recommendations are that training programmes that will address existing knowledge gap in technology utilisation needs to be conducted for the labour force in Africa. Moreover, adequate power supply that will aid effective utilisation of these technologies needs to be put in place by the government in these various African countries.

Keywords: marketing, unemployment, problem, panacea

Procedia PDF Downloads 220
2451 Phytochemical Profile and in Vitro Bioactivity Studies on Two Underutilized Vegetables in Nigeria

Authors: Borokini Funmilayo Boede

Abstract:

B. alba L., commonly called ‘Amunututu’ and Solanecio biafrae called ‘Worowo’ among the Yoruba tribe in the southwest part of Nigeria are reported to be of great ethnomedicinal importance but are among many underutilized green leafy vegetables in the country. Many studies have established the nutritional values of these vegetables, utilization are very poor and indepth information on their chemical profiles is scarce. The aqueous, methanolic and ethanolic extracts of these vegetables were subjected to phytochemical screening and phenolic profiles of the alcoholic extracts were characterized by using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Total phenol and flavonoid contents were determined, antioxidant activities were evaluated using five in vitro assays to assess DPPH, nitric oxide and hydroxyl radical-scavenging abilities, as well as reducing power with ferric reducing antioxidant assay and phosphomolybdate method. The antibacterial activities of the extracts against Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi were evaluated by using agar well diffusion method and the antifungal activity evaluated against food-associated filamentous fungi by using poisoned food technique with the aim of assessing their nutraceutical potentials to encourage their production and utilization. The results revealed the presence of saponnin, steroids, tannin, terpenoid and flavonoid as well as phenolic compounds: gallic acid, chlorogenic acid, caffeic acid, coumarin, rutin, quercitrin, quercetin and kaemferol. The vegetables showed varying concentration dependent reducing and radical scavenging abilities from weak to strong compared with gallic acid, rutin, trolox and ascorbic acid used as positive controls; the aqueous extracts which gave higher concentrations of total phenol displayed higher ability to reduce Fe (lll) to Fe (ll) and stronger inhibiting power against hydroxyl radical than the alcoholic extracts and in most cases exhibited more potency than the ascorbic acids used as positive controls, at the same concentrations, whereas, methanol and / or ethanol extracts were found to be more effective in scavenging 2, 2-diphenyl-1-picryl hydrazyl radical and showed higher ability to reduce Mo (VI) to Mo (V) in total antioxidant assay than the aqueous extracts. However, the inhibition abilities of all the extracts against nitric oxide were comparable with the ascorbic acid control at the same concentrations. There were strong positive correlations with total phenol (mg GAE/g) and total flavonoid (mg RE/g) contents in the range TFC (r=0.857- 0999 and r= 0.904-1.000) and TPC (r= 0.844- 0.992 and r= 0.900 -0.999) for Basella alba and Senecio biafrae respectively. Inhibition concentration at 50 % (IC50) for each extract to scavenge DPPH, OH and NO radicals ranged from 32.73 to 1.52 compared with control (0.846 - -6.42) mg/ml. At 0.05g/ml, the vegetables were found to exhibit mild antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi compared with streptomycin sulphate used as control but appreciable antifungi activities against (Trichoderma rubrum and Aspergillus fumigates) compared with bonlate antibiotic positive control. The vegetables possess appreciable antioxidant and antimicrobial properties for promoting good health, their cultivation and utilization should be encouraged especially in the face of increasing health and economic challenges and food insecurity in many parts of the world.

Keywords: antimicrobial, antioxidants, extracts, phytochemicals

Procedia PDF Downloads 325
2450 Catalytic Combustion of Methane over Pd-Meox-CeO₂/Al₂O₃ (Me= Co or Ni) Catalysts

Authors: Silviya Todorova, Anton Naydenov, Ralitsa Velinova, Alexander Larin

Abstract:

Catalytic combustion of methane has been extensively investigated for emission control and power generation during the last decades. The alumina-supported palladium catalyst is widely accepted as the most active catalysts for catalytic combustion of methane. The activity of Pd/Al₂O₃ decreases during the time on stream, especially underwater vapor. The following order of activity in the reaction of complete oxidation of methane was established: Co₃O₄> CuO>NiO> Mn₂O₃> Cr₂O₃. It may be expected that the combination between Pd and these oxides could lead to the promising catalysts in the reaction of complete methane. In the present work, we investigate the activity of Pd/Al₂O₃ catalysts promoted with other metal oxides (MOx; M= Ni, Co, Ce). The Pd-based catalysts modified by metal oxide were prepared by sequential impregnation of Al₂O₃ with aqueous solutions of Me(NO₃)₂.6H₂O and Pd(NO₃)₂H₂O. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). An improvement of activity was observed after modification with different oxides. The results demonstrate that the Pd/Al₂O₃ catalysts modified with Co and Ce by impregnation with a common solution of respective salts, exhibit the most promising catalytic activity for methane oxidation. Most probably, the presence of Co₃O₄ and CeO₂ on catalytic surface increases surface oxygen and therefore leads to the better reactivity in methane combustion.

Keywords: methane combustion, palladium, Co-Ce, Ni-Ce

Procedia PDF Downloads 186
2449 Value Added by Spirulina Platensis in Two Different Diets on Growth Performance, Gut Microbiota, and Meat Quality of Japanese Quails

Authors: Mohamed Yusuf

Abstract:

Aim: The growth promoting the effect of the blue-green filamentous alga Spirulina platensis (SP) was observed on meat type Japanese quail with antibiotic growth promoter alternative and immune enhancing power. Materials and Methods: This study was conducted on 180 Japanese quail chicks for 4 weeks to find out the effect of diet type (vegetarian protein diet [VPD] and fish meal protein diet [FMPD])- Spirulina dose interaction (1 or 2 g/kg diet) on growth performance, gut microbiota, and sensory meat quality of growing Japanese quails (1-5 weeks old). Results: Data revealed improvement (p<0.05) of weight gain, feed conversion ratio, and European efficiency index due to 1, 2 g (SP)/kg VPD, and 2 g (SP)/kg FMPD, respectively. There was a significant decrease of ileum mean pH value by 1 g(SP)/kg VPD. Concerning gut microbiota, there was a trend toward an increase in Lactobacilli count in both 1; 2 g (SP)/kgVPD and 2 g (SP)/kg FMPD. It was concluded that 1 or 2 g (SP)/kg vegetarian diet may enhance parameters of performance without obvious effect on both meat quality and gut microbiota. Moreover, 1 and/or 2 g (SP) may not be invited to share fishmeal based diet for growing Japanese quails. Conclusion: Using of SP will support the profitable production of Japanese quails fed vegetable protein diet.

Keywords: isocaloric, isonitrogenous, meat quality, performances, quails, spirulina, spirulina

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2448 A Research of the Prototype Fuel Injector for the Aircraft Two-Stroke Opposed-Piston Diesel Engine

Authors: Ksenia Siadkowska, Zbigniew Czyz, Lukasz Grabowski

Abstract:

The paper presents the research results of the construction of an injector with a modified injection nozzle. The injector is designed for a prototype aircraft opposed-piston diesel engine with an assumed starting power of 100 kW. The injector has been subjected to optical tests carried out in a constant volume chamber with the use of a camera allowing to record images at the frequency of 5400 fps and at the resolution of 1024x1024. The measurements were based on a Mie scattering technique with global lighting. Seven repetitions were made for a specific measurement point. The measuring point was selected on the basis of the analysis of engine operating conditions. The analysis focused on the average range of the spray and its distribution. As a result of the conducted research, the range of the fuel spray was defined for the determined parameters of injection. The obtained results were used to verify and optimize the combustion process in the designed opposed-piston two-stroke diesel engine. Acknowledgment: This work has been realized in the cooperation with The Construction Office of WSK 'PZL-KALISZ' S.A.' and is part of Grant Agreement No. POIR.01.02.00-00-0002/15 financed by the Polish National Centre for Research and Development.

Keywords: diesel engine, opposed-piston, aircraft, fuel injector

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2447 Structure-Reactivity Relationship of Some Rhᴵᴵᴵ and Osᴵᴵᴵ Complexes with N-Inert Ligands in Ionic Liquids

Authors: Jovana Bogojeski, Dusan Cocic, Nenad Jankovic, Angelina Petrovic

Abstract:

Kinetically-inert transition metal complexes, such as Rh(III) and Os(III) complexes, attract increasing attention as leading scaffolds for the development of potential pharmacological agents due to their inertness and stability. Therefore, we have designed and fully characterized a few novel rhodium(III) and osmium(III) complexes with a tridentate nitrogen−donor chelate system. For some complexes, the crystal X-ray structure analysis was performed. Reactivity of the newly synthesized complexes towards small biomolecules, such as L-methionine (L-Met), guanosine-5’-monophosphate (5’-GMP), and glutathione (GSH) has been examined. Also, the reactivity of these complexes towards the DNA/RNA (Ribonucleic acid) duplexes was investigated. Obtained results show that the newly synthesized complexes exhibit good affinity towards the studied ligands. Results also show that the complexes react faster with the RNA duplex than with the DNA and that in the DNA duplex reaction is faster with 15mer GG than with the 22mer GG. The UV-Vis (Ultraviolet-visible spectroscopy) is absorption spectroscopy, and the EB (Ethidium bromide) displacement studies were used to examine the interaction of these complexes with CT-DNA and BSA (Bovine serum albumin). All studied complex showed good interaction ability with both the DNA and BSA. Furthermore, the DFT (Density-functional theory) calculation and docking studies were performed. The impact of the metal complex on the cytotoxicity was tested by MTT assay (a colorimetric assay for assessing cell metabolic activity) on HCT-116 lines (human colon cancer cell line). In addition, all these tests were repeated in the presence of several water-soluble biologically active ionic liquids. Attained results indicate that the ionic liquids increase the activity of the investigated complexes. All obtained results in this study imply that the introduction of different spectator ligand can be used to improve the reactivity of rhodium(III) and osmium(III) complexes. Finally, these results indicate that the examined complexes show reactivity characteristics needed for potential anti-tumor agents, with possible targets being both the DNA and proteins. Every new contribution in this field is highly warranted due to the current lack of clinically used Metallo-based alternatives to cisplatin.

Keywords: biomolecules, ionic liquids, osmium(III), rhodium(III)

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2446 Electrospinning Preparation of Superhydrophobic Polydimethylsiloxane/Polystyrene Nanofibrous Membranes for Carbon Dioxide Capture

Authors: Chia-Yu Chang, Yi-Feng Lin

Abstract:

CO2 capture has attracted significant research attention due to global warming. Among the various CO2 capture methods, membrane technology has proven to be highly efficient in capturing CO2 due to the ease at which this technology can be scaled up, its low energy consumptions, small area requirements and overall environmental friendliness for use by industrial plants. Capturing CO2 is to use a membrane contactor with a combination of water-repellent porous membranes and chemical absorption processes. In a CO2 membrane contactor system, CO2 passes through a hydrophobic porous membrane in the gas phase to contact the amine absorbent in the liquid phase. Consequently, additional CO2 gas is absorbed by amine absorbents. This study examines highly porous Polydimethylsiloxane (PDMS)/Polystyrene (PS) Nanofibrous Membranes and successfully coated onto a macroporous Al2O3 membrane. The performance of these materials in a membrane contactor system for CO2 absorption is also investigated. Compared with pristine PS nanofibrous membranes, the PDMS/PS nanofibrous membranes exhibit greater solvent resistance and mechanical strength, making them more suitable for use in CO2 capture by the membrane contactor. The resulting hydrophobic membrane contactor also demonstrates the potential for large-scale CO2 absorption during post-combustion processes in power plants.

Keywords: CO2 capture, polystyrene, polydimethylsiloxane, superhydrophobic

Procedia PDF Downloads 388