Technologies, Volume 5, Issue 4 (December 2017) – 22 articles

Ionic liquids (ILs) have attracted interest among researchers due to their tunable properties, which enable them to be used in a wide variety of applications. However, toxicity and biodegradation studies of ILs proved that most of the aromatic ILs, such as imidazolium, are highly toxic and non-biodegradable. Researchers have investigated several advance oxidation processes (AOPs) in order to evaluate the efficiency of the systems used to remove ILs from wastewater. However, their relatively high cost and environmental concerns have limited the application of these AOPs in industry. This research conducted a photocatalytic study using hybrid nanomaterials to evaluate the efficiency of this system as an alternative AOP system for the removal of ILs from wastewater. The synergistic effect of adsorption–photodegradation was introduced by depositing Fe-TiO₂ onto functionalized activated carbon (AC). Nano-TiO₂ was synthesized using the microemulsion method, then modified with a transition metal, and deposited onto oxidized AC. The photodegradation reaction of 1-butyl-3-methylimidazolium chloride [bmim]Cl was then investigated under simulated visible light irradiation. It was observed that the overall efficiency of the system increased with the increasing amount of Fe loading. Our investigation revealed that extrinsic factors such as solution pH, the initial concentration of ILs, and photocatalyst dosage significantly affect the overall efficiency of the system. The optimum condition for the system was observed at pH 10, with initial ILs at 1 mM at 1 g/L of photocatalyst. The best performance photocatalyst was 0.2Fe-TiO₂/AC. Full article

The application of cold-formed steel channel sections for portal frames becomes more popular for industrial and residential purposes. Experimental tests showed that such structures with long-span up to 20 m can be achieved when knee brace joints are included. In this paper, the influence of knee brace configuration on the optimum design of long-span cold-formed steel portal frames is investigated. The cold-formed steel portal frames are designed using Eurocode 3 under ultimate limit states. A novel method in handling design constraints integrated with genetic algorithm is proposed for searching the optimum design of cold-formed steel portal frames. The result showed that the proposed routine for design optimization effectively searched the near global optimum solution with the computational time is approximate 50% faster than methods being popularly used in literature. The optimum configuration for knee brace joint can reduce the section size of rafter and so the lighter frame could be obtained especially for long-span portal frame. The minimum weight of main frame obtained from optimization process is approximate 19.72% lighter than a Benchmark Frame used in the full-scale experimental test. Full article

All pregnant women need easy access to pregnancy-related personalized information, on-time quality healthcare services and effective communication links with healthcare providers. Smartphone-based devices, communication systems and eHealth applications can play an important role in facilitating some of these services to pregnant women in a fast and efficient way and can thus prevent most of the pregnancy-related complications. The objective of this work is to propose and design a pregnancy care network for pregnant women and healthcare providers. The network model, an eHealth application based on smartphone-based devices and communication systems, is designed to strengthen communication links between health professionals and pregnant women and increase education, awareness and quality of care during pregnancy and childbirth. Full article

Sputtered reactive multilayers applied as a heat source in electronic joining processes are an emerging technology. Their use promises low-stress assembly of components while improving thermal contact and reducing thermal resistance. Nanostructured surface modifications can significantly enhance adhesion and reliability of joints between different materials. This work examines reactive multilayer of nickel and aluminum, directly sputtered on nanostructured black silicon surfaces and compares their phase transformation with reference samples deposited on pristine silicon surface. The investigation of the quenched self-propagating reaction reveals a clear influence of the nanostructured surface on the prolongation of the phase transition. Rapid thermal annealing tests result in the formation of Al_1.1Ni_0.9 phase. The nanostructured interface seems to hinder the full transformation of the parent material. The surface modification improves the adhesion of the formed alloy on silicon surfaces and can possibly increase the reliability of joints based on reactive aluminum/nickel multilayer. The use of black silicon, a nanostructured surface modification, is thus a promising approach to realize reliable multi-material joints in complex systems. Full article

Many Human Activity Recognition (HAR) systems are able to detect sequential executed Activity of Daily Living (ADL). However, a person is capable of doing two things in parallel or pausing one ADL and finishing it later. Thus, a HAR system must be capable of remembering and deciding which ADL is completed and which might be continued after the current ADL. We address this case by combining a stochastic Markov model and a psychological memory function to detect parallel ADL. For the evaluation, we use an input dataset and a publicly available benchmark. Our approach outperforms the leading HAR systems for the used benchmark by 5%, while using a more cost-effective installation environment. Furthermore, we address an unsupervised learning method to train the HAR system and explain the algorithm of parallel ADL detection in detail. Full article

In recent years, virtual reality (VR) technologies have been increasingly used for teaching motion skills to learners. In this paper, the authors employed a VR assistive system for teaching motion skills to learners by the use of an inertial sensor-embedded head-mount-display (HMD). As a step of the development, we studied a motion instruction method using “Head Motion-Associated virtual stereo Rearview (HMAR in short)”, and conducted a study on pose-recognition under a time-consuming vision-restricted condition. Under this condition, subjects were to ensure their remembrance only by vision and taking enough time, and not by using proprioception. The time consuming condition is considered to be antithetical to the instantaneous less time consuming condition, and is expected to contribute to deepening the understanding of the effect of the HMAR. In the experiment, reference poses are displayed to learners with the use of a VR system. In the system, the learners observe the virtual stereo rearview via HMD, and perceive and reproduce the displayed reference poses. Here, the virtual stereo camera that is assumed to observe the reference avatar is associated with the learner’s head motion. The virtual stereo camera is moved around the reference avatar away from the back of the avatar’s head in accordance with the head-rotating motion. As the HMAR was compared with two representative ordinary methods, i.e., a key-switched rearview (KSR) and a mouse-associated rearview (MAR), the elapsed time of the HMAR showed significantly smaller variance, although did not show any significant difference in the mean. Full article

Patients evaluate the quality of home health agencies (HHAs) using the Health Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey. This paper describes a prototype community health information system to help patients select appropriate and quality HHAs, according to the location, proprietary status, type of service, and year of HHA establishment. Five HCAHPS indicators were selected: “summary rating”, “quality of care”, “professional care”, “communication”, and “recommend agency”. Independent t-test analysis showed that agencies offering Speech Pathology, Medical-Social, or Home Health Aide services, receive significantly worse HCAHPS ratings, while mean ratings vary significantly across different US states. Multiple comparisons with post hoc ANOVA revealed differences between and within HHAs of different proprietary status (p < 0.001): governmental HHAs receiving higher ratings than private HHAs. Finally, there was observed a relationship between all five quality rating variables and the HHA year of establishment (Pearson, p < 0.001). The older the agency is, the better the HCAPS summary ratings. Findings provided the knowledge to design of a consumer health information system, to provide rankings filtered according to user criteria, comparing the quality rankings of eligible HHAs. Users can also see how a specific agency is ranked against eligible HHAs. Ultimately, the system aims to support the patient community with contextually realistic comparisons in an effort to choose optimal HH service. Full article

This paper attempts to apply an adaptive network-based fuzzy inference system (ANFIS) for analysis of the resonant frequency of a single-layer single-patch microstrip rectangular patch antenna with two equal size slots which are placed on the patch in the form of parallel to resonance edges. The resonant frequency is calculated as the position of the slots is shifted from the right endpoint to the left endpoint on the patch between −4.2 mm ≤ Xslot ≤ 4.2 mm with the steps of 0.1 mm. The designed antenna is proposed for downlink of X band satellite, broadcasting satellite service, fixed-satellite service uplink, satellite (Earth-to-space), radio navigation, mobile-satellite (Earth-to-space), and KU band which can be achieved at the resonant frequencies of 7.2 GHz, 12.2 GHz, 14.6 GHz, 17.5 GHz and 19.3 GHz. Next, High Frequency Electromagnetic Field Simulation software (ANSYS HFSS) results for the prototype microstrip antenna are compared with the values obtained through ANFIS system. It can be concluded that the adaptive network-based fuzzy inference system in such designs can be conveniently used due to fuzzy system’s high approximation capability and much faster convergence rate. The best results for our ANFIS system can be obtained if Gaussian membership is used which leads to the mean absolute error of 1.4653. Full article

Nowadays, the rapidly increasing energy consumption of communication equipment is an economic and environmental problem that needs to be addressed. Small Local Area Networks (LAN) switches in the US alone consume about 8 TWh per year that corresponds to hundreds of millions of US dollars in electricity. A main reason is communication equipment, due to the fact that, Ethernet switches have to active all days even in low-traffic time. There are many approaches to make the switches sensitive with the different traffic load environment, but they have to put some changes to current Ethernet that cause the incompatibility issues. This paper proposes a new device called Modified Multiplexer (MUXER), which can control the power functions of switches without modifying the current Ethernet protocol. The MUXER devices are put before the switches in the network, which provide some functions to transfer incoming Media Access Control (MAC) data frames to the corresponding switches managed by MUXERs. By using the proposed device, the wasted energies in the network can be reduced, especially in the specified low-traffic time. We describe the result of numerical analysis and compare detail power consumption data between a normal and a network where MUXERs are installed. In this work, the explained result shows that if a network administrator can estimate the number of MUXER needed for a particular network and install accordingly, our device can provides a significant energy saving. Full article

In this paper, we report on the evaluation strategy and the results that were obtained from the final end-user evaluation process of an innovative robotic assistive device supporting mobility. More specifically, the paper deals with the evaluation of the MOBOT robotic rollator as regards to the system’s overall performance and its individual assistive characteristics and functionalities, as implemented in respect to (i) the provided cognitive assistance, and (ii) the adopted audio-gestural human-robot communication model. User evaluation was designed on the basis of an extensive survey of scales and methodologies widely reported in the relevant literature. The actual evaluation phase exploited the QUEST 2.0, ATDPA-Device Form, and PYTHEIA scales to measure the subjective satisfaction of the users. The PYTHEIA scale, in particular, was structured in order to fill the gaps that were identified during the study of previously existing tools for measuring assistive device user satisfaction. The scale was applied for the first time during the reported evaluation process. An analysis of the results showed that MOBOT was ranked very high by end users in all of the aspects addressed by the three employed assessment scales, thus providing significant evidence for positive acceptance of any industrialized outcome of the current prototype in the assistive robots market. Full article

In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation methodology does, however, require more space that may not be available when refurbishing older process plants. Relocating structural elements would introduce much hot work, which should be minimized in live plants. It is also costly. The aim of the present study is therefore to develop a test concept for testing fire resistance of equipment protected with only air-gap and thermal insulation, i.e., without the fire-protective insulation. The present work demonstrates a conceptual methodology for small scale fire testing of mockups resembling a section of a distillation column. The mockups were exposed to a small-scale propane flame in a test configuration where the flow rate and the flame zone were optimized to give heat flux levels in the range 250–350 kW/m². Results are presented for a mockup resembling a 16 mm thick distillation column steel wall. It is demonstrated that the modern distance insulation in combination with the heat capacity of the column wall indicates 30+ minutes fire resistance. The results show that this methodology has great potentials for low cost fire testing of other configurations, and it may serve as a set-up for product development. Full article

Distributed manufacturing even at the household level is now well established with the combined use of open source designs and self-replicating rapid prototyper (RepRap) 3-D printers. Previous work has shown substantial economic consumer benefits for producing their own polymer products. Now flexible filaments are available at roughly 3-times the cost of more conventional 3-D printing materials. To provide some insight into the potential for flexible filament to be both technically feasible and economically viable for distributed digital manufacturing at the consumer level this study investigates 20 common flexible household products. The 3-D printed products were quantified by print time, electrical energy use and filament consumption by mass to determine the cost to fabricate with a commercial RepRap 3-D printer. Printed parts were inspected and when necessary tested for their targeted application to ensure technical feasibility. Then, the experimentally measured cost to DIY manufacturers was compared to low and high market prices for comparable commercially available products. In addition, the mark-up and potential for long-term price declines was estimated for flexible filaments by converting thermoplastic elastomer (TPE) pellets into filament and reground TPE from a local recycling center into filament using an open source recyclebot. This study found that commercial flexible filament is economically as well as technically feasible for providing a means of distributed home-scale manufacturing of flexible products. The results found a 75% savings when compared to the least expensive commercially equivalent products and 92% when compared to high market priced products. Roughly, 160 flexible objects must be substituted to recover the capital costs to print flexible materials. However, as previous work has shown the Lulzbot Mini 3-D printer used in this study would provide more than a 100% ROI printing one object a week from hard thermoplastics, the upgrade needed to provide flexible filament capabilities can be accomplished with 37 average substitution flexible prints. This, again easily provides a triple digit return on investment printing one product a week. Although these savings, which are created by printing objects at home are substantial, the results also have shown the savings could be further increased to 93% when the use of a pellet extruder and TPE pellets, and 99% if recycled TPE filament made with a recyclebot is used. The capital costs of a recyclebot can be recovered in the manufacturing of about 9 kg of TPE filament, which can be accomplished in less than a week, enabling improved environmental impact as well as a strong financial return for heavy 3-D printer users. Full article

The vertical flow constructed wetland (VFCW) has become an attractive decentralised technology for septage treatment. One of the main purposes of the septage treatment is to reduce the volume of raw septage through dewatering, where the solids content is retained in the wetland bed and the water content is released. The retention of solids forms a layer of sludge deposit at the wetland surface, and the drained water, the so-called leachate, typically contains a lower solids content. This article reports the performance of dewatering and filtration of a pilot-scale VFCW designed for septage treatment. A comparison between two feeding strategies, hydraulic loading rate (HLR) and solids loading rate (SLR), is presented. The dewatering efficiency through drainage was found to be dependent on the solids load. The removal of total solids (TS) and chemical oxygen demand (COD) were excellent as the quality of leachate showed that more than 90% of TS and COD were retained in the system. This study reveals that the feeding based on SLR delivered a more sustainable performance for dewatering and solids removal. The build-up of sludge deposit significantly deteriorated the dewatering efficiency through drainage, but it tended to improve the filtration capacity. Full article

The present study’s main objective was to determine the applicability of organic phase change materials (PCMs) in a building’s envelope construction system for the passive provision of comfortable indoor thermal conditions over one year based on thermal inertia in Mexico City. Research on PCMs relate mainly to their use in building envelope construction systems to reduce energy consumption for mechanical indoor thermal conditioning—not in passive systems. Computer simulation results of mean indoor temperature variations are presented with the objective of evaluating these construction systems’ thermal inertia properties. In the present study, dynamic thermal simulations (DTS), using EnergyPlus software, of ten 1 m³ test units with envelope construction systems combining organic PCMs of different fusion temperatures with conventional materials were performed. Based on the results, it is concluded that the implementation of organic PCMs with a fusion temperature around 25 °C in combination with aerated concrete in a space envelope results in the highest number of hours the indoor temperatures remain within the comfort range throughout a typical year, due to the decrement of indoor temperature oscillations and, to a large extent, to thermal lag. Full article

In this paper, a robust method of feto-maternal heart rate extraction from the non-invasive composite abdominal Electrocardiogram (aECG) signal is presented. The proposed method is based on the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) method, in which a composite aECG signal is decomposed into its constituent frequency components called Intrinsic Mode Functions (IMFs) or simply “modes”, with better spectral separation. Decomposed IMFs are then selected manually according to probable maternal and fetal heart rate information and are processed further for quantification of maternal and fetal heart rate and variability analysis. The proposed method was applied to aECG recordings collected from three different sources: (i) the PhysioNet (adfecgdb) database; (ii) the PhysioNet (nifecgdb) database; and (iii) synthetic aECG signal generated from mathematical modeling in the LabVIEW software environment. An overall sensitivity of 98.83%, positive diagnostic value of 97.97%, accuracy of 96.93% and performance index of 96.75% were obtained in the case of Maternal Heart Rate (MHR) quantification, and an overall sensitivity of 98.13%, positive diagnostic value of 97.62%, accuracy of 95.91% and performance index of 95.69% were obtained in case of Fetal Heart Rate (FHR) quantification. The obtained results confirm that CEEMDAN is a very robust and accurate method for extraction of feto-maternal heart rate components from aECG signals. We also conclude that non-invasive aECG is an effective and reliable method for long-term FHR and MHR monitoring during pregnancy and labor. The requirement of manual intervention while selecting the probable maternal and fetal components from “n” number of decomposed modes limits the real-time application of the proposed methodology. This is due to the fact that the number of modes “n” produced by the CEEMDAN decomposition is unpredictable. However, the proposed methodology is well suited for applications where a small time-delay or offset in feto-maternal monitoring can be acceptable. In future, application-specific modification of the CEEMDAN algorithm can be implemented to eliminate manual intervention completely and will be suitable for long-term feto-maternal monitoring. Full article

In this study, a photovoltaic (PV) modules site installed from 1997 to 2017 (20 years of outdoor exposure) in the hot, humid region of Kumasi, Ghana in Sub-Saharan Africa was selected in order to study the aging phenomenon and rate of degradation due to long-term exposure. The main purpose of this work was to correlate the performance of 14 PV modules using data from infra-red thermal imaging (hot spot tests), current-voltage (I-V) tests and visual inspection. The modules were first visually inspected followed by electrical performance tests using an I-V curve tracer. Hot spot testing of each module was performed to enable further characterization. The results of the visual inspection using the United States National Renewable Energy Laboratory (NREL) checklist did not show any major observable defects. The results also show that the higher the temperature difference in the hot spot tests, the higher the rate of power degradation. Eleven modules failed the hot spot tests according to the criteria indicated in the literature. The average power degradation rate was 1.36%/year, which is above the industry-accepted range of 0.7–1.0%/year. The results provide evidence of a positive correlation between temperature difference and performance parameters such as power degradation (Pdeg), power performance factor (PPF) and power drop (Pdrop). The power performance factor for all 14 modules fell below the average 80% standard set by most manufacturers for modules operating within the 25-year warranty. Full article

Training of neural networks requires large amounts of data. Simulated data sets can be helpful if the data required for the training is not available. However, the applicability of simulated data sets for training neuronal networks depends on the quality of the simulation model used. A simple and fast approach for the simulation of ground and honed surfaces with predefined properties is being presented. The approach is used to generate a diverse data set. This set is then applied to train a neural convolution network for surface type recognition. The resulting classifier is validated on the basis of a series of real measurement data and a classification rate of >85% is achieved. A possible field of application of the presented procedure is the support of measurement technicians in the standard-compliant evaluation of measurement data by suggestion of specific data processing steps, depending on the recognized type of manufacturing process. Full article

Some applications, including disaster monitoring and recovery networks, use low-power wide-area networks (LPWAN). LPWAN sensors capture data bits and transmit them to public carrier networks (e.g., cellular networks) via dedicated gateways. One of the challenges encountered in disaster management scenarios revolves around the carry/forward sensed data and geographical location information dissemination to the disaster relief operatives (disaster relief agency; DRA) to identify, characterise, and prioritise the affected areas. There are network topology options to reach its destination, including cellular, circuit switched, and peer-to-peer networks. In the context of natural disaster prediction, it is vital to access geographical location data as well as the timestamp. This paper proposes the usage of Pseudo A Number (PAN), that is, the calling party address, which is used by every network to include the location information instead of the actual calling party address of the gateway in LPWAN. This PAN information can be further analysed by the DRA to identify the affected areas and predict the complications of the disaster impacts in addition to the past history of damages. This paper aims to propose a solution that can predict disaster proceedings based on propagation and the velocity of impact using vector calculation of the location data and the timestamp, which are transmitted by sensors through the PAN of the gateway in LPWAN. Full article

Despite recent advances in prosthetics and assistive robotics in general, robust simultaneous and proportional control of dexterous prosthetic devices remains an unsolved problem, mainly because of inadequate sensorization. In this paper, we study the application of regression to muscle activity, detected using a flexible tactile sensor recording muscle bulging in the forearm (tactile myography—TMG). The sensor is made of 320 highly sensitive cells organized in an array forming a bracelet. We propose the use of Gaussian process regression to improve the prediction of wrist, hand and single-finger activation, using TMG, surface electromyography (sEMG; the traditional approach in the field), and a combination of the two. We prove the effectiveness of the approach for different levels of activations in a real-time goal-reaching experiment using tactile data. Furthermore, we performed a batch comparison between the different forms of sensorization, using a Gaussian process with different kernel distances. Full article

In this paper the quantum hydrodynamic approach for the Klein–Gordon equation (KGE) owning a perturbative self-interaction term is developed. The generalized model to non-Euclidean space–time allows for the determination of the quantum energy impulse tensor density of mesons, for the gravitational equation of quantum mechanical systems. Full article

The management of rapidly growing municipal solid waste (MSW) is one of the major challenges in developing countries. The current study also estimates the suitability of a site through a geographical information system using multi-criteria decision analysis (MCDA) for landfill sites in National Capital Territory (NCT). The results of the suitability index indicate that only 58.7 km² of the land is suitable for the construction of landfill sites, while 194.27 km² of the total area is moderately suitable. The existing three landfill sites that are currently functional and used by government organizations as landfills are found to be moderately suitable. A large fraction of MSW is disposed in landfills, which emit one third of the total anthropogenic methane (CH₄) and are considered an important contributor of Green House Gases (GHGs) to the atmosphere. Thus, there is a need for the proper estimation of GHG emission from landfills, specifically CH₄, which contributes 20% of the GHGs that contribute to global warming. The current study aims to estimate the CH₄ emission from landfills in the NCT, Delhi, India using GHG inventory guidelines from the Intergovernmental Panel on Climate Change (IPCC). The CH₄ emission from landfills has doubled from 31.06 Gg/yr to 65.16 Gg/yr from 1999 and 2000 to 2015. The generation of CH₄ from MSW is strongly correlated (R² = 0.58) with the Gross State Domestic Product (GSDP), which is an indicator of wellbeing. Full article

This article focuses on how operator wellbeing can be assessed to ensure social sustainability and operator performance at assembly stations. Rapid technological advances provide possibilities for assessing wellbeing in real-time, and from an assembly system perspective, this could enable the assessment of physiological data in real-time. While technology is available, it has not been implemented or tested in industry. The aim of this paper was to investigate empirically how concurrent physiological measurement technologies can be integrated into an industrial application, in order to increase operator wellbeing and operator performance. A mixed method approach was used, which included a literature study, two laboratory tests, two case studies and a workshop. The results indicated that operator wellbeing could be assessed through electro-dermal activity, but that the data is perceived as difficult to interpret. For an industrial application, operator perception and data presentation are important and risks connected to personal integrity and IT-support need to be addressed. Future work includes testing how a combination of physiological measures and self-assessments can be used to assess operator wellbeing in an industrial context. Full article