Preferred Technology Research Articles

A TECHNICAL AND ECONOMIC COMPARISON OF CO2 REMOVAL TECHNOLOGIES IN AMMONIA PRODUCTION PLANTS

The utilization of natural gas as a primary feedstock in ammonia production has resulted in significant carbon dioxide (CO2) emissions, raising environmental concerns. Consequently, several technologies have been developed to capture and remove carbon dioxide. In this study, a comparison was conducted between two CO2 removal technologies (Amine and Benfield) in an Ammonia production plant. The evaluation was performed using rate-based modelling techniques in Aspen Plus software. A base case simulation was built and validated using figures obtained from various literature studies. Optimization and sensitivity analyses were conducted to determine optimal operating conditions. The optimized parameters were used to perform an economic analysis of both technologies based on the energy consumption, solvent regeneration efficiency, and CO2 removal efficiency. The results obtained from the comparison showed that the amine technology was more economical than the Benfield technology in terms of cost and plant efficiency. The economic analysis revealed that the amine technology had a lower Net Present value, and a shorter payback period compared to the Benfield technology. Overall, this study provides insight into the economic and operational considerations of CO2 removal technologies in ammonia production plants and recommends the use of amine technology as the preferred technology for CO2 removal in ammonia production plants.

Influence of material thickness and hatching strategies on laser cutting of epoxy mold composites

Glass-filled composites are used for overmolding of electrical components due to their good electrical isolation properties. Laser cutting is a preferred technology to remove excess mold material to achieve a low surface roughness and reduce tool wear. Hatching strategies improve the laser-cutting process of carbon fiber-reinforced polymers toward lower cutting times and a more homogeneous cut surface. The impact of hatching strategies on epoxy mold compounds has been so far unknown as the laser-cutting strategy was based on multiple single passes in previous studies. This work investigates the effects of hatching strategies such as perpendicular hatching, parallel hatching, and a single line, including the influence of material thickness and filler content regarding the cutting time, kerf taper angle, and heat-affected zone, using a 50 W short-pulsed fiber laser for different highly filled epoxy mold compounds. Results show that the use of a hatching strategy is required to cut workpieces at thicknesses of 4 mm or higher due to the sieving size of the filler. Perpendicular hatching needs to be chosen when the aim is a minimal cutting time. The kerf taper angle at the top of the cut is below 4° while hatching leads to a more pronounced kink of up to 25° occurring toward the bottom of the cut. Meanwhile, an increase in filler concentration leads to an increase in cutting time, because of higher thermal conduction, while no effect on the kerf taper angle or the heat-affected zone can be identified.

The potential of electrodialysis as a cost-effective alternative to reverse osmosis for brackish water desalination

While electrodialysis (ED) demonstrates lower energy consumption than reverse osmosis (RO) in the desalination of low salinity waters, RO continues to be the predominant technology for brackish water desalination. In this study, we probe this skewed market share and project the potential for future disruption by ED through systematic assessment of the levelized cost of water (LCOW). Using rigorous process- and economic-models, we minimize the LCOW of RO and ED systems, highlighting important tradeoffs between capital and operating expenditure for each technology. With optimized current state-of-the-art systems, we find that ED is more economical than RO for feed salinities ≤ 3 g L−1, albeit to a minor extent. Considering that RO is a highly mature technology, we focus on predicting the future potential of ED by evaluating plausible avenues for capital and operating cost reduction. Specifically, we find that reduction in the price of ion-exchange membranes (i.e., < 60 USD m−2) can ensure competitiveness with RO for feed salinities up to 5 g L−1. For higher feed salinities (≥ 5 g L−1) we reveal that the LCOW of ED may effectively be reduced by decreasing ion-exchange membrane resistance, while preserving high current efficiency. Through extensive assessment of structure-property-performance relationships, we precisely identify target membrane charge densities and diffusion coefficients which optimize the LCOW of ED, thus providing novel guidance for future membrane material development. Overall, we emphasize that with a unified approach — whereby ion-exchange membrane price is reduced and performance is enhanced — ED can become the economically preferable technology compared to RO across the entire brackish water salinity range.

Evaluación Tecno-económica de alternativas para calentamiento doméstico de agua para la ciudad ecuatoriana de Cuenca

INTRODUCTION. Homes in the Andean region of Ecuador, due to the relatively cold ambient temperature, require energy services such as hot water in a daily basis along the year. In that context, the preferred technologies used for such purpose run on LPG, mainly, due to its low cost as it is highly subsidized. This situation poses certain challenges for the energy policy of the country. OBJECTIVE. This case study aims to discuss more sustainable alternatives to obtain hot water for household use in the context of the Andean city of Cuenca. METHOD. Firstly, solar and meteorological data has been processed to characterize local conditions. Then, different technologies able to provide hot water have been simulated. Further, an economic analysis was performed to determine costs per unit of energy required. RESULTS. The use of subsidized LPG reduces the real cost of water heating between 47% and 72% depending on the daily levels of consumption. In the event of a subsidy removal, electric tankless water heaters, along with reduced electricity tariffs, become competitive for levels of consumption up to 120 liters per day. For higher levels of consumption solar thermal systems or heat pumps may become viable only when providing rebates DISCUSSION AND CONCLUSIONS. The presence of benefits of scale among levels of consumption need to be regarded when designing incentives for energy services such as domestic hot water.

Delphi consensus project on prostate-specific membrane antigen (PSMA)-targeted surgery-outcomes from an international multidisciplinary panel.

Prostate-specific membrane antigen (PSMA) is increasingly considered as a molecular target to achieve precision surgery for prostate cancer. A Delphi consensus was conducted to explore expert views in this emerging field and to identify knowledge and evidence gaps as well as unmet research needs that may help change practice and improve oncological outcomes for patients. One hundred and five statements (scored by a 9-point Likert scale) were distributed through SurveyMonkey®. Following evaluation, a consecutive second round was performed to evaluate consensus (16 statements; 89% response rate). Consensus was defined using the disagreement index, assessed by the research and development project/University of California, Los Angeles appropriateness method. Eighty-six panel participants (72.1% clinician, 8.1% industry, 15.1% scientists, and 4.7% other) participated, most with a urological background (57.0%), followed by nuclear medicine (22.1%). Consensus was obtained on the following: (1) The diagnostic PSMA-ligand PET/CT should ideally be taken < 1month before surgery, 1-3months is acceptable; (2) a 16-20-h interval between injection of the tracer and surgery seems to be preferred; (3) PSMA targeting is most valuable for identification of nodal metastases; (4) gamma, fluorescence, and hybrid imaging are the preferred guidance technologies; and (5) randomized controlled clinical trials are required to define oncological value. Regarding surgical margin assessment, the view on the value of PSMA-targeted surgery was neutral or inconclusive. A high rate of "cannot answer" responses indicates further study is necessary to address knowledge gaps (e.g., Cerenkov or beta-emissions). This Delphi consensus provides guidance for clinicians and researchers that implement or develop PSMA-targeted surgery technologies. Ultimately, however, the consensus should be backed by randomized clinical trial data before it may be implemented within the guidelines.

THE EFFECT OF DIFFERENT SLICING SOFTWARE ON THE MANUFACTURING PERFORMANCE OF 3D PRINTED PARTS

Plastic 3D printing is currently in-trend for producing custom parts and products with intricate geometry. Fused Filament Fabrication (FFF) is one of the preferred technologies, as it requires a simple operation with affordable equipment setup. Previous studies have achieved many breakthroughs in using FFF. To successfully produce parts using the FFF machine, a slicing software is required to provide instructions to the machine. Currently, numerous slicing software are available in the market that can be integrated to the FFF machine. Each slicing software has a slightly different performance compared with others. Therefore, careful consideration should be taken when choosing the most suitable slicing software for the machine in use. In this work, three slicing software, namely, Ultimaker Cura 4.8.0, Cura 2.7.0, and PrusaSlicer have been chosen to investigate their effect on the manufacturing performance of 3D printed parts. The parameters for evaluating manufacturing performance were accuracy of the slicing software in predicting printing time, the dimensional accuracy of the printed parts, and the surface roughness of the printed parts. The effect of printing speed was also investigated at three levels, which were at 20, 40, and 60 mm/s. In this work, the 3D Espresso F220 machine was used. The geometry of the printed parts followed the ASTM D638 Type I geometry using polylactic acid (PLA) filament material. The results showed that Ultimaker Cura 4.8.0 can produce the best results, if the priority of the producer is to use a software with high accuracy in printing time prediction and better surface quality. However, if the priority of the process is to produce small dimensional errors (close tolerance to designed geometry), the characteristics of the dimension (length, width, or thickness) need to be identified. Ultimaker Cura 4.8.0 produced small errors when the critical dimension was width, but Cura 2.7.0 was good for length dimension, while PrusaSlicer was good for thickness dimension. The results also showed that printing speed can affect the time of completion of the printed parts and the surface quality. The lowest printing speed was able to produce parts with better surface quality; however, printing time can become longer.

Personalized Cancer Vaccines Go Viral: Viral Vectors in the Era of Personalized Immunotherapy of Cancer

The aim of personalized cancer vaccines is to elicit potent and tumor-specific immune responses against neoantigens specific to each patient and to establish durable immunity, while minimizing the adverse events. Over recent years, there has been a renewed interest in personalized cancer vaccines, primarily due to the advancement of innovative technologies for the identification of neoantigens and novel vaccine delivery platforms. Here, we review the emerging field of personalized cancer vaccination, with a focus on the use of viral vectors as a vaccine platform. The recent advancements in viral vector technology have led to the development of efficient production processes, positioning personalized viral vaccines as one of the preferred technologies. Many clinical trials have shown the feasibility, safety, immunogenicity and, more recently, preliminary evidence of the anti-tumor activity of personalized vaccination, fostering active research in the field, including further clinical trials for different tumor types and in different clinical settings.

In-plane seismic behaviour of urm and confined masonry built from vertically perforated blocks and polyurethane glue

Masonry construction using vertically perforated clay blocks with large holes and polyurethane glue is a modern technology designed primarily for low thermal losses. This study aims to evaluate the in-plane seismic behaviour of masonry constructed using unreinforced masonry (URM) and confined masonry construction technology. The experimental methods consist of triplet tests on joints and cyclic shear compression tests on eight full-scale walls, six of which are URM and two of which are confined masonry. Tests on URM walls are performed at three different levels of compressive stress to analyse the effect of compressive stress on the seismic response. The effects of compressive stress on shear resistance and drift capacity are quantified and compared with results from a database. The performance of the tested walls is comparable to what is expected from modern URM walls. Two confined masonry walls were of the same dimensions as the URM walls and are evaluated at the highest compressive stress level used in tests of URM walls. The results indicate that confined masonry should be the preferred technology for seismic regions because of its higher strength, displacement capacity, ductility, and energy dissipation.

Telemedicine implementation framework for Malaysia: An integrated SWOT-MCDM approach

ObjectivesDespite the increase in the utilization of telemedicine worldwide, especially during the pandemic, its implementation in Malaysia's healthcare industry remains scarce. Hence, this study aims to understand the current state of telemedicine utilization by identifying the constraints and establishing the optimum telemedicine implementation strategy. MethodsThe study proposes an integrated methodology based on strengths, weaknesses, opportunities, and threats (SWOT) analysis, analytical hierarchy process entropy (AHPE), and fuzzy technique for order performance by similarity to the ideal solution (FTOPSIS). The SWOT analysis is performed for the situational assessment of telemedicine technology in Malaysia. Each element of SWOT was assessed using AHPE to establish priorities, followed by the FTOPSIS approach to provide strategies for its successful adoption. ResultsThe findings show that continuous government support and encouragement for market acquisition, cost-cutting, profit-maximizing, and Internet of Things (IoT)-based adoption to establish a strong telemedicine network is the most important strategy for telemedicine technology implementation. While using a structured method to improve service quality, the implementation of a knowledge-sharing management program for telemedicine technology is ranked as the least preferred telemedicine technology implementation strategy. ConclusionsThe study suggests a systematic way of developing and evaluating telemedicine technology implementation strategies for further improving Malaysian healthcare patient experiences and policy endeavours. This study proposed alternative strategies to expand telemedicine technology implementation. It is hoped that this study could further enhance knowledge and serve as a guide for stakeholders in the healthcare industry to understand their business environment better.

The preferred IT sources and tools of Iranian people for accessing health information

IntroductionPeople need health information to maintain their health. Despite the variety of sources and tools for providing health information, there is little evidence about Iranian people's preferences in using these sources and tools. The objective of this study was to identify the preferred health information sources, tools, and methods for presenting health information in these tools.MethodsThis national survey was conducted among a sample of 4000 Iranian people between April and September 2021. The data was collected using a valid and reliable questionnaire (α = 0.86) consisting of four sections: participants' demographic information, current sources of obtaining health information, preferred information technology (IT) tools for accessing health information, and the method of presenting this information. Linear regression was used to investigate the relationship between demographic factors and other questions.ResultsThe participants received health information mostly from the "Internet" (3.62), "family or friends" (3.43), "social networks" (3.41), "specific websites" (3.41), and "mobile apps" (3.27). "Social networks" (3.67), Internet "websites" (3.56), and "mobile apps" (3.50) were the most suitable tools for receiving health information. The participants preferred the presentation of health information in the form of "Images" (3.85), "educational videos" (3.69), and "texts" (3.53). Age, education, and marital status had a significant relationship with most of the preferred information sources, tools, and information presentation methods (p < 0.05).ConclusionThe results of this study showed that Iranian people are more active information seekers than passive ones compared to a decade ago. The preferred sources and tools identified in this research can be used by healthcare planners and policy-makers in Iran and other developing countries to design and develop IT interventions that meet people's needs. Improving access to the Internet, social networks, and mobile apps and providing health information via images, educational videos, and texts on these platforms enhance access to the information people need.

Effect of powder milling on sintering behavior and monotonic and cyclic mechanical properties of Mo and Mo–Si lattices produced by direct ink writing

Molybdenum is a refractory metal regarded as a promising basis for producing high-temperature components. However, the potential of manufacturing molybdenum-based structures by direct ink writing (DIW) has not been explored. In this study, three-dimensional porous molybdenum (Mo) and molybdenum-silicon (Mo–Si) composite lattices were fabricated using DIW with non-milled and milled powders. The effects of Mo powder morphology (resulting from milling) and chemical composition (alloying Mo with 3 and 10 wt% of Si) on the microstructure, phase composition, and static and cyclic compression properties at room temperature were investigated. Lattices fabricated from commercial spherical Mo powder exhibited the highest intra-filament porosity. Conversely, lattices fabricated from milled Mo powder were denser and had higher compressive strength, offset stress, and quasi-elastic gradient. Alloying Mo with Si during sintering resulted in composite lattices with Mo + Mo3Si microstructure. A low content of Mo3Si slightly decreased monotonic compression properties but did not affect the cyclic compression response compared to Mo lattices made from milled powder. In contrast, a high content of Mo3Si produced quasi-brittle lattices with reduced compressive strength and increased damage accumulation during cyclic loading. The cyclic behavior of all lattices was characterized by a ratcheting-dominated stress-strain response. Lattices fabricated from milled Mo and milled Mo-3 wt.%Si powders demonstrated superior performance compared to those fabricated from commercial spherical Mo and milled Mo-10 wt%Si powders. The results suggest that using milled powders can enhance the mechanical reliability and promote the use of DIW as preferred additive manufacturing technology for the fabrication of Mo–Si composite lattices.

Prediction and optimization of liquid dispersion of monoethanolamine in a rotating packed bed for CO2 absorption

Rotating packed bed (RPB) has recently gained traction as a preferred technology for the absorptive removal of CO2. In this device, solvent dispersion is the most crucial hydrodynamic parameter that directly affects the liquid-side mass transfer coefficient. The current study focuses on the optimization of the dispersion of monoethanolamine (MEA), a commonly used CO2 absorption solvent, in the RPB. Computational fluid dynamics (CFD) model was developed and validated against the published experimental data. The validated model was used to investigate the effect of operational parameters such as solvent concentration, rotational speed of the packed bed, inlet velocity, and the contact angle of packing material on MEA dispersion. The liquid dispersion of MEA was modeled using response surface methodology (RSM), artificial neural network (ANN) and adaptive neuro-fuzzy inference systems (ANFIS). The comparison of the modeled data revealed that ANN has the least mean square error (0.16) and is, therefore, the most capable model to predict the liquid dispersion of MEA in the RPB. Based on the ANOVA analysis, the inlet velocity of MEA is found to be an insignificant parameter and, therefore, does not contribute significantly to the liquid dispersion of MEA in the RPB. At optimized operating conditions, the MEA dispersion increased from 5346 to 10485 m−1, thus enhancing the physical absorption of CO2 up to eight times. CFD coupled with ANN for the prediction and RSM for the optimization of liquid dispersion can be employed to optimize industrial-scale RPB for the effective absorptive removal of CO2.

Electrochemically activated Mn3O4 nanoparticles as higher performing electrode than MnO2 for Al-ion batteries – An insight into the crystallographic changes caused by Al3+ intercalation

Aluminium is the third most abundant element in the earth's crust, with a high theoretical capacity and volumetric energy density, making aluminium ion batteries (AIBs) a preferred technology for future large-scale energy storage applications amongst all of the proposed nonlithium-based battery systems. However, the practical realization of AIBs has so far been impeded by the frequent collapse of the host framework of the cathode materials. Here, nanostructure of Mn3O4 is being reported as a cathode material for aqueous AIBs to enhance the specific capacity, rate capability, and cycling stability. The various salts of aluminium were used as an electrolyte to verify how the composition of the electrolyte affected the intercalation and deintercalation of Al3+ in Mn3O4 electrode. In AlCl3 aqueous electrolyte, the Mn3O4 cathode exhibits the highest initial discharge capacity of ∼ 271 mAh g−1, at a high current density of 0.5 A g−1, with an excellent capacity retention of 98 % after 1,000 cycles. The outstanding cycling stability of the synthesized Mn3O4 nanoparticles is established by considering the phase transition from Mn3O4 spinel to MnO2 layered structure. The intercalation/deintercalation of Al3+ into/from the Mn3O4 crystal structure is also being confirmed by analysing the electrochemical performance in NaCl, KCl, and H2SO4 electrolyte.

Evaluation and Prioritization of Power-Generating Systems Using a Life Cycle Assessment and a Multicriteria Decision-Making Approach

Millions of people in Asia and sub-Saharan Africa still lack access to power, which emphasizes the need for sustainable and clean energy solutions. This study attempts to address this issue by integrating a life cycle assessment (LCA) and a multicriteria decision-making (MCDM) analysis to determine the preferred energy technology for electrification. This research focuses on the environmental implications and long-term viability of various energy system options. The LCA evaluates midpoint characterization containing 18 environmental impact categories; the COPRAS and ARAS methods of MCDM analysis are then used to rank the energy alternatives based on their environmental performance. This study’s key finding is that the gas-powered power plant is the most preferred energy system alternative, while the geothermal power plant is the least preferred. This midpoint characterization study provides in-depth insights into how various stages contribute to major environmental impact categories like global warming, ozone depletion, and ecotoxicity. By considering environmental impacts and sustainability requirements, informed decisions may be made to encourage clean and cost-effective power generation, thereby contributing to climate change mitigation and supporting economic growth and human development. Future research may include analysis from cradle-to-grave compared to cradle-to-gate.

Unleashing the power of shark variable single domains (VNARs): broadly neutralizing tools for combating SARS-CoV-2.

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) generated a joint global effort to develop vaccines and other treatments that could mitigate the negative effects and the rapid spread of the virus. Single-domain antibodies derived from various sources, including cartilaginous fish, camelids, and humans, have gained attention as promising therapeutic tools against coronavirus disease 2019. Shark-derived variable new antigen receptors (VNARs) have emerged as the smallest naturally occurring antigen-binding molecules. Here, we compile and review recent published studies on VNARs with the capacity to recognize and/or neutralize SARS-CoV-2. We found a close balance between the use of natural immune libraries and synthetic VNAR libraries for the screening against SARS-CoV-2, with phage display being the preferred display technology for the selection of VNARs against this virus. In addition, we discuss potential modifications and engineering strategies employed to improve the neutralization potential of VNARs, such as exploring fusion with the Fc domain of human Immunoglobulin G (IgG) to increase avidity and therapeutic potential. This research highlights the potential of VNARs as powerful molecular tools in the fight against infectious diseases.

Life cycle assessment of electrochemical and mechanical energy storage systems

The effect of the co-location of electrochemical and kinetic energy storage on the cradle-to-gate impacts of the storage system was studied using LCA methodology. The storage system was intended for use in the frequency containment reserve (FCR) application, considering a number of daily charge–discharge cycles in the range of 50–1000. The results show that a significant environmental benefit (up to a 96% decrease in cradle-to-gate global warming potential, from 1.65 ± 0.12 to 0.059 ± 0.004 kg CO2-eq./kWh) can be obtained by the co-location of battery and flywheel storage systems, owing to the ability of the flywheel component to preserve battery lifetime by delivering the frequent charge events required in the FCR application. A moderate saving of 24% in global warming potential (from 1.65 ± 0.12 to 1.26 ± 0.11 kg CO2-eq./kWh) could already be achieved by switching from a battery to flywheel storage system with repeated charge–discharge cycling (200 or more charge events per day). This study highlights the need to consider the intensity of charge–discharge cycling when choosing an environmentally preferable storage technology as well as introducing a methodology for incorporating the number of daily cycles in the analysis.

On the Acid Stability of PGM-Free OER Catalyst for H2 Production in PEMWE

Low temperature proton exchange membrane water electrolyzer (PEMWE) represents a critical technology for green hydrogen production. It offers the advantages of significantly higher current density and higher H2 purity, rendering it a preferred technology when high energy efficiency and low footprint are essential.Working in the oxidative and acidic environment under high polarization voltage, however, adds substantial demand to the electrode catalyst and the support. This is particularly the case at anode where the oxygen evolution reaction (OER) takes place. At present, the platinum group metal (PGM) materials such as Ir black or Ir oxide are catalysts of choice. Their high cost and limited reserve, however, adds a significant cost to PEM electrolyzer, which contributes to the overall expense of hydrogen production next only to the cost of electricity. Replacing Ir with earth-abundant transition metal oxides could help to reduce the electrolyzer system cost.Argonne National Laboratory has recently designed and prepared a new family of PGM-free OER catalyst for PEM electrolyzer. The new catalysts have high porosity and unique nanoarchitecture, and have demonstrated very promising activity and durability in both rotating disk electrode (RDE) and in operating PEMWE.The most challenging aspect of PGM-free OER catalyst is its stability in the acidic media. To this end, we conducted extensive structural characterizations as well as computational modeling. Particularly, in situ X-ray absorption spectroscopy combined with high resolution imaging revealed insightful information on the electronic and surface structural changes during the electrochemical reaction. Computational Pourbaix diagram also elucidated the catalyst stability under the acidic OER operating condition. Acknowledgement: This work is supported by U. S. Department of Energy, Hydrogen and Fuel Cell Technologies Office through Office of Energy Efficiency and Renewable Energy and by Office of Science, U.S. Department of Energy under Contract DE-AC02-06CH11357.

Flame curtain kilns produce biochar from dry biomass with minimal methane emissions

Flame curtain kilns have emerged as the preferred biochar technology for smallholders but reported methane emissions (30 g kg−1 biochar) have impeded carbon certification. Here, for flame curtain kilns we show almost no methane (0–3.6 g kg−1 biochar) emissions for dry (<15 % moisture) feedstock consisting of twigs and leaves. Wet feedstock (>40 % moisture) however generated significant methane (>500 g kg−1 biochar), underscoring that feedstock preparation is decisive for the carbon balance. Even for dry feedstock, both aerosol and CO emissions were significant (21–82 and 40–118 g kg−1 biochar, respectively). The data demonstrate that certification of low-tech biochar made from dry twigs and leaves should not be objected to on the grounds of methane. Careful selection of feedstock and potential after-combustion of the syn-gases are probably needed to avoid CO and aerosol emissions. More data are needed on methane emissions of other dry feedstocks.

Facebook Messenger: As Means of Communication for Academic Inquiries

Most of social media users use Facebook Messenger as a messaging platform because of its free messaging and video chatting service. Thus, it is not a surprise that Facebook Messenger is utilized as a communication tool for academic purposes. This descriptive qualitative research anchored on the epistemology constructionism, methodology and naturalistic inquiry aimed to determine how do students use Facebook-Messenger as means of communication for academic inquiries. The aforesaid study was conducted among the twelve (12) BSED Social Studies learners who were identified through purposeful sampling. The researchers utilized a semi-structured written interview which contains one question anchored in the Task-Technology Fit (TTF) Theory. On the other hand, the data and information were collected through essay form and analyzed through Conventional Qualitative Content Analysis. In using Facebook Messenger as a means of communication for academic inquiries, the informants from BSED Social Studies expressed that the platform is avenue for academic skills, task-needs, and their preferred technology. First, informants expressed that Facebook Messenger is an avenue for academic skills because it (1) facilitates collaboration, its (2) easy navigation of features, and (3) fosters teacher-learner communication. Also, Facebook Messenger fills for their task-need as it helps them conduct (1) group discussion, (2) convenient submission, have (3) clear instruction, and (4) task clarity. Lastly, informants show evidence that the platform is their preferred technology because it is an (1) alternative platform, (2) file-sharing platform, (3) provide storage for preference, (4) up-to-date reminder, and a (5) convenient tool for communication. This study reveals that Facebook Messenger is used as a tool to open an avenue for academic skills, is an essential platform for delivering task needs, and was a preferred technology as a means of communication for academic inquiries.

Green hydrogen for ammonia production – A case for the Netherlands

An integrated system is studied to supply green hydrogen feedstock for ammonia production in the Netherlands. The system is modeled to compare wind and solar resources when coupled to Alkaline Electrolysis (AEL) and Proton Exchange Membrane Electrolysis (PEMEL) technologies with a compressed hydrogen storage system. The nominal installed capacity of the electrolysis plant is around 2.3 GW, with the most suitable energy source offshore wind, and the preferred storage technology pressurized tubes. For Alkaline Electrolysis and Proton Exchange Membrane Electrolysis technologies, the levelized cost of hydrogen is 5.30 €/kg H2 and 6.03 €/kg H2, respectively.