Search

Photovoltaic thermal-assisted solar infrared dryer and a battery-operated drying system for agricultural products were created in experimental research to lessen the demand for fossil fuels. The drying cabinet's sustainability index and energy efficiency were calculated in the experiments carried out at flow rates of 0.022 and 0.062 kg/s. As a result, the Improvement Potential (IP) index values for the two studies were calculated to be 2.42 and 1.19, respectively. These numbers are 2.38 and 4.06 for Sustainable Index (SI); 0.47 and 0.27 were derived for Waste Exergy Ratio (WER). In the two experiments, the average drying cabinet exergy was found to be 0.55 and 0.71, respectively. Likewise, it was found that the drying time is influenced by the flow rate; the drying times in the two experiments were 310 and 280 min, respectively. Additionally, it was determined that for the two experiments, the thermal efficiency of the photovoltaic thermal collector was 33.11% and 55.07%, its electrical efficiency was 11.65% and 12.38%, and its exergy efficiency was 0.85 and 1.15, respectively. The development and assembly of a brand-new, cost-effective photovoltaic/thermal collector that is based on air. Determining factors for the system include energy, exergy, and sustainable indicators. Energy saving 66.32%; Electrical efficiency increase 6.27%; Exergy efficiency increase 35.29% Drying cabinet exergy efficiencies increase %29.09. [ABSTRACT FROM AUTHOR]

In this study, Kemer eggplants (Solanum melongena L.) were examined in terms of system performance and energy efficiency after drying at constant air temperature and different operating systems developed on a heat pump dryer. The air velocity and the drying time have a negative correlation was observed. In addition, the Midilli & Kucuk model was the most appropriate model to explain the experimental data of dried eggplant samples obtained from this study. Effective moisture diffusivity was calculated between 6.08 × 10−10 and 7.30 × 10−10 m2/s depending on air velocity values. The reduction of the eggplant slices from 12.158 (g water/g dry matter (dm)) moisture value to 0.645 (g water/g dm) moisture value took 236 min at 1 m/s air velocity with the application of Serial Condenser and Parallel Evaporator Drying System (SCPEDS). The Serial Condenser Drying System (SCDS) was found to yield both the highest average condenser capacity with 2.256 kW and the highest system performance coefficient with 3.181. The brightness values (L) of dried eggplant samples increased compared to the fresh eggplant samples. The closest brightness value to the fresh samples was determined as 84.7 in the drying experiments with the air velocity of 0.5 m/s and the SCPEDS system. The other color parameters (b, C and h°) decreased during drying. The highest total color change value (8.05) was obtained with SCPEDS system at 1.0 m/s. The highest browning index value (63.48) was reached in the drying experiments performed with the SCDS system at 0.75 m/s. [ABSTRACT FROM AUTHOR]

The general use of wireless sensor devices and their importance in terms of deployment cost, size and user-friendliness have given an increase to many different applications of cognitive radio networks. In cognitive radio networks, energy efficiency is a very important problem. In the literature, many different methods are developed by researchers which are not able to produce the best results. Hence, in this article, a hybrid technique is developed to attain energy efficiency deliberation intended for properly maintaining objective signal to interference plus noise ratio (SINR) need for the received interferences and cognitive users at a receiver of primary under a reference value. In the proposed methodology, interference threshold protection margin and protection factor to the SINR target are developed. The hybrid WOFA algorithm can be a combination of the Whale Optimization Algorithm (WOA) and Firefly Algorithm (FA). In the WOA algorithm, updating positions of the whales are achieved with the utilisation of the FA algorithm. The proposed method is designed in the MATLAB platform, and it is compared with the existing approaches of WOA by robustness in addition to energy efficiency under the disturbance of channel gain. The proposed method is analysed with the two different cases such as the target SINR ratio condition of 3.52 dB and the target SINR ratio condition of 5.11 dB. [ABSTRACT FROM AUTHOR]

This study investigates the effects of several contextual variables, including renewable energy intensity, capital stock per labor, natural resource rent, the share of imported energy in total energy consumption, the ratio of carbon emissions to GDP, population, and energy production on energy efficiency in EU countries. While Tobit regression is used to examine the effects of contextual variables on energy efficiency, Data Envelopment Analysis (DEA), Slack-Based Data Envelopment Analysis (SBM-DEA), and Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) are used to calculate energy efficiency values of countries. Four different Tobit regression models are estimated as a function of the censored value for the energy efficiency series. The results show that renewable energy intensity, the ratio of carbon emissions to GDP, and population size have negative effects on energy efficiency. In contrast, regardless of the efficiency level, the share of imported energy in total energy consumption, total energy production, capital stock per labor, and technological progress have positive effects on energy efficiency. [ABSTRACT FROM AUTHOR]

The current EU regulatory framework is forcing the need for a substantial and significant reduction of greenhouse gas emissions in all the main economic sectors since climate change effects have been more tangible in recent years. The adoption of actions and measures to reduce CO2 emissions are thus essential for preventing global warming. For this reason, a simplified bottomup approach is presented here to estimate the potential environmental benefit achievable, in terms of CO2 emissions saving, when a set of proposed energy efficiency measures were adopted in relevant economic sectors of the UNESCO area of Vineyard Landscape in Piedmont Region in Italy. Specifically, representative case studies were assumed for each economic sector being studied to identify the energy efficiency measures to be adopted. Then, progressive scenarios with different territorial diffusion of the proposed measures were performed. The analysis shows that a CO2 emission reduction from 7.1% to 32.4% can be potentially obtained by considering different diffusion pathways of the identified energy efficiency measures in the residential, accommodation, private transport, and food industry sectors, so that the UNESCO area can effectively contribute to contrast global warming. The proposed simplified approach can be replicated in other similar context to obtain rough estimation of emission savings due to territorial diffusion of energy efficiency measures considering available regional and local databases. [ABSTRACT FROM AUTHOR]

Abstract Internationally, rental properties have fewer energy efficiency features than other homes, causing unnecessary carbon emissions and poor health outcomes for tenants. Landlords are the primary decision-makers for energy efficiency retrofitting of rental properties, yet their retrofit behaviour is not well understood. We surveyed 500 small-scale private landlords in Victoria, Australia, to examine how a range of variables impacted landlords’ energy-efficient retrofitting. Landlords who installed more retrofits were more likely to have greater concern for tenants’ comfort, a relationship with the tenant, or greater knowledge of property conditions. Despite the existing literature and in contrast to the research on owner-occupiers, financial variables, environmental concerns, and sociodemographic variables were not associated with landlords’ retrofitting. We propose that policies may be more effective if they are framed in pro-social (rather than pro-environmental or financial terms) and convey information about the impact of property conditions on tenants’ wellbeing. [ABSTRACT FROM AUTHOR]

Leakage of air in tumble dryers is an important parameter regarding the energy efficiency of the drying process. In general, tumble dryers are prone to leakage, therefore further investigation and optimization in this field is of great interest. This study investigates and quantifies leakage of air within the closed-loop system of an in-situ household heat pump tumble dryer. Each potential leakage location was characterized by leakage curve obtained either by isolated or cumulative measurements using system pressurization method. Based on the static pressure distribution within the closed-loop system, the leakage outflow and inflow were quantified. The leakage of air at the rear and front drum seal was evaluated with and without drum movement. The results indicated the highest leakage outflow rate at the heat pump housing, which represents 12,6% of the total drying air flow rate within the closed-loop system. Sealing heat pump housing improved the condensation efficiency from B to A class according to the IEC 61121. [ABSTRACT FROM AUTHOR]

Citrus residue is a large-scale agro-industrial biowaste that can become a source of renewable energy through drying. Drying demands high power consumption due to the low energy efficiency of this process in the industries. In this work, the energy performance of the drying process in a semi-industrial rotary drum of 2.7 m length and 0.45 diameter was analyzed. The main objective was to find the operational condition for the lowest energy consumption and also the highest energy, drying and exergetic efficiencies. The experiments were performed under different solid mass flow rates (0.2 and 0.4 kg/min) inlet air velocities (1 and 2 m/s) and temperatures (135, 145, and 155 °C). The average energy efficiency was 13.1% with 25.1% of drying efficiency, 37291.3 kJ/kg of specific energy consumption, and 37.3% of exergy efficiency. The results showed that the drying technique can be an interesting alternative to add value to the citrus residue. [ABSTRACT FROM AUTHOR]

For a biomass power plant, which uses a biomass fuel having a high moisture content, flue gas drying is an effective method of increasing the overall power plant efficiency. However, this method requires flue gas that has a high temperature. Most biomass power plants, however, are designed so that flue gas temperature is already reduced to a low value through the installation of economizer and air heater. This paper investigates the use of steam-air preheater to raise both air temperature and flue gas temperature. Therefore, steam-air preheater enhances the potential of flue gas dryer, and both devices can be used in conjunction to raise the overall efficiency of a biomass power plant. Models of power plant, flue gas dryer, and steam-air preheater are used in this paper to demonstrate by simulation that the integration of flue gas dryer and steam-air preheater results in 2.52% increase in electrical power output of a reference power plant that consumes a fuel with 52% moisture content (wet-basis) if the fuel moisture removal rate in flue gas dryer is 7140 kg/h, and the total heating surface area of steam-air preheater is 2000 m2. The simple payback period for the investment in this integration is 3.3 years. [ABSTRACT FROM AUTHOR]

Based on passive heat and mass transfer enhancement technology, a control method combining a cylindrical obstacle and a flexible beam was proposed to improve heat transfer performance in a microchannel. The optimal layout of a flexible beam was investigated under varying inclination angles of the beam and its spacing distances to the cylindrical obstacle through two-dimensional simulations of heat transfer, fluid and solid interaction. The control mechanism of the flexible beam was qualitatively analyzed from views of flow pattern and structural vibration. It was found that the pressure loss and heat flux should be considered simultaneously, to achieve the best performance of the heat transfer. Results showed that optimal performance occurred when the inclination angle of the beam and its spacing distance to the cylinder took specific values. In such circumstances, the flexible beam's vibration was amplified by the periodic vortex shedding from the upstream cylinder, without introducing too large a blocking effect. The appropriate control strategy of fluid-structure interaction can enhance the disturbance of the thermal boundary layer and result in the largest thermal enhancement factor. [ABSTRACT FROM AUTHOR]

Residential clothes drying consume about 650 TBtu of primary energy per year in the United States, equivalent to 3% of primary residential energy consumption. There is a strong impetus to reduce the energy consumption of clothes dryers by both improving existing technology and developing alternatives that use fundamentally different drying mechanisms. Clothes drying technologies are broadly classified into either evaporative or mechanical drying. The focus of this paper is on mechanical drying, including vibrational, centrifugal, and press-based methods. In this work, the physical processes involved in these mechanical fabric drying processes were analyzed to develop general theories of mechanical cloth drying energy efficiency. Quantitative evaluation of the theories requires measured fabric properties. To accomplish this, a set of experiments was conducted on samples of a standard test fabric. The fabric was a cotton-polyester blend specified by the US Department of Energy to evaluate the standardized efficiency of all residential clothes dryers in the US. Mercury porosimetry experiments were conducted to determine the fabric pore size distribution, apparent density, and porosity. Elasticity experiments were conducted to determine the fabric's Young's modulus. Isostatic press experiments were conducted to establish a relationship between compression force and fabric moisture content. The data resulting from these experiments were combined with mathematical models developed in this work to calculate the theoretical maximum performance limits for mechanical drying of the standard fabric. The results of the analysis are used to make recommendations for the most promising technologies that offer the greatest potential energy savings for residential clothes drying. [ABSTRACT FROM AUTHOR]

The decarbonisation strategy of the building sector, which accounts for 24% of national greenhouse gas (GHG) emissions, is important to achieve climate neutrality in Korea by 2050. In this study, a bottom-up model and four scenarios were developed for examining scenarios for the decarbonisation of the residential building by 2050. A comparative analysis of energy consumption, GHG emissions, and investment cost was performed. The result showed that building energy performance improvement and heating fuel electrification are key measures for decarbonisation. We concluded that an investment of KRW 6.2 trillion per year would be required to achieve the 2050 decarbonisation scenario. Policy strategies were proposed for increasing investment in accelerating building retrofit, mandating zero-energy building (ZEB), and prohibiting gas boilers. [ABSTRACT FROM AUTHOR]

Currently, there is no official green or sustainable built environment evaluation system in Turkey. When a certification is required for a building or a site, various certification systems are employed. To meet the demand, the Turkish Green Building Council released an evaluation system called B.E.S.T. in 2013. In this paper, the B.E.S.T. evaluation system is introduced as well as a sample application. The evaluation of the Yalova University Engineering Faculty Building using the B.E.S.T. evaluation system is presented. Field research was conducted and evidentiary documents were gathered in preparation. The study employed both analytical and field research methodologies in this regard. As a result of the study, Yalova University Engineering Faculty Building was assessed to be eligible for the lowest level certificate, the 'Approved' degree of the B.E.S.T. evaluation system. Furthermore, the results achieved with the B.E.S.T. were compared to those acquired previously with other green or sustainable building evaluation systems. HIGHLIGHTS - An exemplary set of the evaluation was performed for university campus buildings with the B.E.S.T. certification system. - The conducted case study is one of the earliest samples of B.E.S.T. evaluations. - A comparison of B.E.S.T. with LEED and BREAM is provided. - The importance of establishing a local certification system has been discussed. [ABSTRACT FROM AUTHOR]

To broaden the efficient operating zone and increase the energy efficiency of a multi-stage double-suction centrifugal pump, a multi-component and multi-condition optimization design method involving high-precision performance predictions, a flow loss visualization technique based on entropy production theory, and machine learning is proposed. First, the accuracy of the baseline pump numerical methodology is verified via a grid convergence analysis and experiments. Thereafter, nine design parameters of the impeller and double volute are selected as design variables. Subsequently, 150 designs are created according to the Latin hypercube sampling method (LHS) and numerically simulated using an automatic simulation program. A backpropagation neural network (BPNN) and a multi-objective genetic algorithm (MOGA) are adopted to maximize the efficiency at 0.6Qd, 1.0Qd, and 1.2Qd. Finally, the optimal results are verified via numerical calculations and analyzed. The results indicate that the efficiency of the optimized pump is increased by 2.05%, 3.56%, and 5.36% at 0.6Qd, 1.0Qd, and 1.2Qd, respectively. The comparative analysis of the energy characteristics reveals that the improved performance of the optimized pump can be attributed to the improved matching between the rotor and stator. This research further demonstrates the accuracy and reliability of the optimization method using an artificial neural network (ANN). [ABSTRACT FROM AUTHOR]

In this work, the industrial case study of effluent drying with a direct and hybrid heat recovery configuration is investigated for the purpose of improving heat recovery potential and understanding the influence of various design parameters on the performance indicators in the spray drying process. Initially, data collection and performance analysis of industrial spray dryer of effluent management is performed. Then, the effect of design variables such as recirculation ratios, mass flow rate of dry hot air, water vapor, temperature of the mixing chamber, and heat input on performance parameters (thermal efficiency, energy savings, and the sustainability index) are evaluated for several configurations of the spray drying unit used in effluent management. As an outcome, substantial improvement in energy efficiency (83%) and energy-saving (26%) was achieved for a spray drying system with a 70% recirculation ratio of exhaust air for a hybrid heat recovery configuration, which is approximately 2.5% higher than the direct heat recovery configuration and it is significantly higher than that without an energy recovery system. In addition, a significant reduction in the blower power and heat input is noted in the direct and hybrid heat recovery system. The sustainability index is higher for the hybrid heat recovery configuration, indicating it being the most environment friendly configuration. The absolute humidity in the exhaust air is kept constant during entire investigation for uniformity in analysis. [ABSTRACT FROM AUTHOR]

Freeze drying has been a very successful technology in the food and pharma industries, particularly owing to the benefits it offers in terms of product quality. It is most recommended for high-value foods and those that contain heat-sensitive ingredients. Over the years, to meet industry requirements, several variants of the freeze-drying technology have been developed, even to meet specific drying applications. The process of freeze-drying is highly energy-intensive and time-consuming. Nevertheless, innovative techniques are available with the potential to produce products at reduced drying times and lower cost, while being environment-friendly and maintaining freeze-dried quality. This review summarizes advances in the application of infrared, microwave, ultrasound, pulsed electric field, and other techniques as pretreatments and/or to assist conventional freeze-drying processes. Freeze drying combined with other techniques can provide more benefits in terms of energy, time, and cost savings. In this review, comparative studies have been presented to describe these aspects. Such techniques to assist the freeze-drying process can be linked well with sustainable food processing strategies, particularly considering a significant reduction in energy requirements. [ABSTRACT FROM AUTHOR]

A region-adaptive hierarchical framework for realizing Sustainable Development Goal 7.3 is proposed in this paper, using Nigeria as a case study for strategy adoption and adaptation. In 2013, the Economic Community of West African States (ECOWAS) rolled out strategic plans to phase out incandescent lamps by 2020, as a critical component essential to realizing the SDG 7 by 2030. However, at the expiration of the 2020 deadline, this ambition has not materialized. Current regulatory indicators for sustainable energy shared by the World Bank and the International Energy Agency (IEA) indicated poor-to-average performances among member states, which suggests the need to adopt ingenious strategies to increase electricity access and accelerate energy efficiency by 2030. In this paper, we systematically reviewed literatures on past campaigns in ECOWAS member states and inferentially call for a revisit of the campaign to phase out incandescent bulbs as a critical component for achieving energy efficiency. The paper also pinpoints some domain factors that are militating against the realization of SDG 7 in Nigeria. We proposed an all-inclusive top-down hierarchical framework which involve all relevant stakeholders (national, state and local governments, delineated wards in local governments, street representatives and household heads), civil society organizations, and educational institutions, for convergence, efficient collaboration, synergy and achievement of goals. [ABSTRACT FROM AUTHOR]

One of the capable technologies in networking systems is the Multiple-Input Multiple-Output (MIMO) technology as it provides better system capacity and a high Bit Error Rate (BER). Still, the transmit antenna selection remains as the greatest issue. More transmit antennas are necessary to achieve maximum capacity, which leads to increased power consumption. Therefore, for solving these issues in the M-MIMO system, this paper introduces a novel Wolf Adapted Herding algorithm (WA-HA) for selecting the optimal transmit antennas using multi-objective constraints that raise the capacity and Energy Efficiency (EE). The proposed algorithm combines the concept of Elephant Herding Optimization (EHO) and Grey Wolf Optimization (GWO) algorithm and it is referred to as the Wolf Adapted Herding Algorithm (WA-HA). This WA-HA algorithm optimises the number of transmit antennas and hence decides which antenna has to be chosen. Finally, the performance of the adopted method is evaluated over other traditional methods like MV-GSA, SLnO, I-SLnO, EHO and GWO in terms of various metrics like EE and capacity. In particular, the capacity of the proposed WA-HA method for ZF under set-up 1 is 51.02%, 30.61%, 22.44%, 8.163% and 55.10% better than the existing models. Furthermore, the computational time of our model is 10.96%, 26.13%, 14.08%, 13.48% and 10.26% superior to that of the existing models, respectively. [ABSTRACT FROM AUTHOR]

The continuous increase in energy demand has led to the gradual depletion of fossil fuels and the corresponding environmental degradation. As a result, the implementation of energy efficiency measures, as well as the integration of Renewable Energy Sources systems, are a challenge on the road towards Nearly-Zero Energy Buildings. Within the framework of this study, an extensive literature review was carried out on the existing Photovoltaic/Thermal collector technologies, their energy, environmental and economic efficiency. Furthermore, a solar combi system with photovoltaic/thermal collectors installed in a residential building was studied. The system was evaluated for its energy and environmental efficiency. Finally, the results in terms of thermal efficiency and carbon footprint were compared with those of a solar combi system with a flat plate collector. [ABSTRACT FROM AUTHOR]

This study explores the (de)motivations of small, independently-owned, hotels to conserve the environment in the Aral Sea region of Uzbekistan. This destination provides an interesting case study as it represents one of the world's most deprived regions with a scarce resource base. This resource scarcity should prompt hotels to conserve the environment. However, this resource scarcity may prevent environmental conservation as the limited resources can be spent on other operational tasks. By interviewing senior hotel managers, this study showcases their limited motivation for environmental conservation. The study highlights the role of various stakeholders in encouraging hotels to save the environment. Recommendations are made on policy and management interventions required to incentivize environmental conservation by hoteliers. [ABSTRACT FROM AUTHOR]

The throughput of a belt conveyor system is the primary design parameter when considering a new installation, determined by the cross-section of the material on the belt, coupled with the belt speed. Optimizing this area not only improves efficiency, but also minimizes capital costs through the optimal selection of equipment. Whilst speed-related optimization has seen considerable attention, the cross-sectional area has largely been neglected due to existing design constraints of the system. Conventional belt conveyors typically utilize a 3-idler troughing configuration, which forms a trapezoidal cross-section with a parabolic surcharge. The rigidity of this support directly limits the geometry of the cross-section that may be considered. A new conveyor system developed at the University of Newcastle supports the conveyor belt by a rail-based carriage, with no relative movement between the belt and carriage. This configuration allows the cross-section of the belt to be freely optimized in order to maximize the material throughput for a given belt width, or alternatively to minimize the belt width for a given throughput. This article utilizes the calculus of variations to optimize the form of this cross section, and demonstrates that an increase in throughput of up to 30% is possible, compared to troughed installations. [ABSTRACT FROM AUTHOR]

Paper drying is the most energy-intensive step in papermaking and around 90% of the total amount of manufactured paper is produced in multi-cylinder dryers. A framework based on a physical model of multi-cylinder drying was developed to assess the effect of various energy-saving measures at a production site. The framework was applied to the drying section of a paper machine producing corrugated paper. The calculated steam and power savings reach up to 1.55 GJth/tpaper and 0.1 GJel/tpaper respectively, depending on the chosen combination of efficiency measures. The cumulative effect of the measures is not equal to the sum of their individual effects, which highlights the importance of accounting for interactions when considering the implementation of several measures. [ABSTRACT FROM AUTHOR]

High Pressure Grinding Rolls (HPGR) is a high-energy efficiency device that has the ability to weaken the particle. This leads to lower energy consumption at subsequent grinding stages. Currently, no commonly used standard indices exist for predicting breakage, and weakening behavior of particles by HPGR. Accordingly, the current study mainly aimed at investigating the relationship between the common grindability/mechanical characteristics of rock (including work index, Brazilian tensile strength, elasticity module, and uniaxial compressive strength) and the breakage and weakening behaviors of HPGR products. For this purpose, six samples (pure calcite, pure magnetite, pure quartz, marmarite rock, travertine rock, and copper ore) with identical particle size distribution were comminuted by HPGR at three pressure force levels of 2.5, 4.5, and 7.5 MPa. Then, the breakage behavior of the samples was evaluated based on the size reduction ratio, followed by studying the weakening of particles by measuring changes in the fundamental breakage and deformation characteristics (mass-specific fracture energy and stiffness) by Impact Load Cell (ILC). The results revealed an excellent relationship between the breakage behavior of particles and their Brazilian tensile strength, as well as their weakening behavior and elasticity module. For particles with a higher module of elasticity (resistivity toward deformation), energy would be consumed for the formation of cracks and subsequently, particle weakening. In the case of particles with a lower module of elasticity, energy is probably dissipated as particle deformation, resulting in more cake formation and less weakening in particles. [ABSTRACT FROM AUTHOR]

Energy efficiency policies can help to reduce energy use and mitigate the effects of climate change. This paper examines the U.S. and Chinese economies by applying HEM to both. Key sectors absorbing more energy from other sectors by purchasing intermediate products from them and, simultaneously, transferring more energy by selling products to the rest of the sectors are identified. This provides insights for decision-making on appropriate energy efficiency policies. It appears that the U.S. economy should focus on the service sector, and the Chinese should focus on the industrial sector. [ABSTRACT FROM AUTHOR]

This paper investigates the effectiveness of different energy scenarios for achieving early reductions in global energy-related CO2 emissions on trajectories to zero or near-zero emissions by 2050. To keep global heating below 1.5°C without overshoot by 2050, global CO2 emissions must decline by about half by 2030. To achieve rapid, early emission reductions entails substantially changing recent pre-COVID (2000–2019) observed trends, which comprise increasing total primary energy supply (TPES) and approximately constant fraction of TPES derived from fossil fuels (FF fraction). Scenarios are developed to explore the effects of varying future trends in these variables in the absence of substantial CO2 removal, because relying on the latter is speculative and risky. The principal result is that, to reduce energy-related emissions to at least half the 2019 level by 2030 en route to zero or near-zero CO2 emissions by 2050, either TPES must be reduced to at least half its 2019 value by 2050 or impossibly rapid reductions must be made in the FF fraction of supply, given current technological options. Reduction in energy consumption likely entails economic degrowth in high-income countries, driven by policies that are socioeconomic, cultural and political, in addition to technological. This needs serious consideration and international cooperation. Key policy insights If global energy consumption grows at the pre-COVID rate, technological change alone cannot halve global CO2 emissions by 2030 and hence cannot keep global heating below 1.5°C by 2050. In the absence of substantial CO2 removal, policies are needed to reduce global energy consumption and hence foster degrowth in high-income economies. Policies to drive technological and socioeconomic changes could together cut global energy consumption and thus total primary energy supply and associated emissions by at least 75% by 2050. [ABSTRACT FROM AUTHOR]

Drying is an energy-intensive operation for the separation of a desired solid product, when it consumes 12–20% of the entire energy used in manufacturing processes. Without changing the existing drying method or equipment, making α-form of L-glutamic acid (α-Glu) by reactive crystallization can reduce the energy consumption for drying in terms of much less initial moisture content of 23.32% and time of 4.67 h , as compared to 48.52% and 6 h for its β-form in the present study. Upon drying, α-Glu shows less affinity for hydrogen bonding with water, as ammonia cations on α-carbon of L-Glu are projected on the α-Glu's surface. On the contrary, more hydrophilic carboxylate anions on α-carbon are exposed on the surface of β-Glu, which tends to form agglomerates during reactive crystallization, causing stronger interaction with water. As a consequence, 35% of energy utilization in drying can be saved by making α-Glu. [ABSTRACT FROM AUTHOR]

With the proliferation of the internet of things (IoT) and device-to-device (D2D) communications enabled by the boom of mobile computing technology, secure high-speed communication has now become indispensable in our daily life. This is especially true when potentially private data are being continually sensed by and communicated among mobile devices as they exist in a world of interconnected inanimate objects, which is also one of the main themes of the upcoming 5G revolution. As the amount of data to be secured for high-speed communications is vast, there is a need to ensure that the block ciphers used for encryption are deployed without incurring significant computational cost. In this paper, we present fast implementations of recent industry standard block ciphers in typical embedded platforms, consisting of multi-core CPU (ARM A15 and A7) and GPU (Mali T628). We implemented the conventional block cipher (AES) and lightweight block ciphers (CLEFIA, SIMON, SPECK and PRESENT) optimized for fast computation. We also analyze the energy efficiency of these block ciphers computation in CPU and GPU, as low power consumption is crucial for the embedded system. Our experimental results show that the embedded GPU is not only able to compute block ciphers faster than conventional CPU but also consumes significantly less power. [ABSTRACT FROM AUTHOR]

Although DC power is claimed to be more energy-efficient than AC power for EHD drying, experimental studies on this subject are still insufficient. This research compares the efficiency of DC versus AC (60 Hz frequency) power for EHD drying by using 1 × 1 and 2 × 2 multi-pin discharge electrodes. Energy indicators were determined from the measurements of electric power consumption at the corresponding drying rate of the wet tissue paper. The experiments revealed the key benefits of DC drying, such as enhanced drying rate, higher energy efficiency, and lower specific energy consumption. For the comparable drying flux of 0.2 g/(m2 s), the specific energy consumption of DC drying was in the range from 350 J/g (2 × 2) to 750 J/g (1 × 1) as compared with 2000 J/g (2 × 2) to 5000 J/g (1 × 1) for AC. The specific energy consumption of a 2 × 2 discharge electrode was consistently smaller than the 1 × 1 one, indicating the role of emitters spacing in the process efficiency. The specific energy consumption of both electrodes increased with the drying rate. [ABSTRACT FROM AUTHOR]

A wireless sensor network requires judicious utilization of its limited energy resources. As a result, the energy efficient algorithms have become a pre-requisite for healthy and prolonged functioning of these networks. Consequently, the present work minimizes the energy expenditure, maximizes the node utilization, incurs less state switching, and prolongs the network lifetime by proposing a partly centralized and partly distributed sleep wake scheduling for the overlapped dominating sets. The concepts of such a hybrid scheduling and overlapped dominating sets have not been explored to their full potential for continuous sensing. Therefore, the research work presented in this paper shall be a stepping stone to further explore the suggested concept for the purpose of reducing energy consumption in wireless sensor networks. It is envisioned that the proposed approach shall be beneficial in battlefield monitoring, security surveillance, environmental monitoring etc., which necessitate long-term continuous/non-periodic coverage of the target region. The proposed sleep wake scheduling algorithm is hybrid in nature and possesses the advantages of both distributed and centralized approaches. The superiority and significance of the results have been established by a comparative analysis with other existing techniques mentioned in the literature. [ABSTRACT FROM AUTHOR]

The highly dynamic hybrid nature of legged locomotion makes it a very challenging task to control. A proper control strategy, besides the ability to generate stable motions, should also possess generalization capabilities and adjustability to different conditions. In this regard, this work takes a step forward in promoting the concept of Force Modulated Compliance (FMC) control as a bioinspired reflex-based control approach and assesses its potential in generating various hopping motions. The FMC is an easy-to-tune and simplified representation of the neuromuscular control, which functions as an adjustable spring modulated by the ground reaction force. We implemented the FMC controller on EPA-Hopper-II which is an extension of our previous electric-pneumatic actuation (EPA) designs. By optimizing control parameters for hopping frequencies of 1.5 − 3.5 H z and different PAM configurations in the robot structure, we show that FMC can generate stable hopping motions and adapt to different configurations. The optimization results also show that leg stiffness has a high correlation with normalized energy consumption. Increases in leg stiffness decrease the normalized energy consumption and vice versa. The outcomes of this study, particularly the highlighted generalization of the FMC control, open new doors for efficient control of legged robots and assistive devices. [ABSTRACT FROM AUTHOR]

This work investigates the evenness of fabric drying in a household heat pump tumble dryer. The evenness of drying was defined as the standard deviation of the fraction of water, evaporated from each fabric item. Drying experiments were performed according to the IEC 61121 standard, which was also followed to determine quantities and types of cotton fabric items (towels, pillowcases and sheets) within each load. Regression analysis was performed to develop models for evenness of drying as a function of load mass and drum speed. Similarities between the tumble dryer energy efficiency parameters and the evenness of drying were analyzed. A high level of agreement was determined between responses of energy efficiency, drying time and evenness of drying to changes in drum speed. Effects of load mass were however more complex and were reflected in a non-linear response of evenness of drying to changes in load mass – the best evenness of drying could be obtained at 2 kg load, followed by 6 kg and 4 kg load. Load composition was determined as an important factor affecting the evenness of drying. At larger loads, a sheet or a pillowcase in average contributed more to the un-evenness of drying than a towel. The presence of sheets and probably the ratio of sheets to other item types in the load were determined as the most probable factors that negatively affected the evenness of drying. [ABSTRACT FROM AUTHOR]

Non-orthogonal multiple access (NOMA) attains a promising result for the several access problems and fulfils the requirements of fifth-generation (5G) networks by strengthening the service quality, like massive connectivity and energy efficiency. To achieve the power allocation of multiple users with the layered transmission, the NOMA is extended with the multiple input multiple output (MIMO) system. In this work, the allocation of power in MIMO–NOMA is optimally done with the layered transmission by the developed Fractional Salp Particle Swarm Optimisation (FSPSO) algorithm. In the MIMO–NOMA, the implemented FSPSO algorithm attained the better sum rate using allocating the powers at multiple layers of users. Also, the closed-form phrase is formed for the achievable sum rate using the Channel State Information (CSI) existing at the side of transmitter. To increase the achievable sum rate, the CSI permits the users to assign the powers at various layers. The proposed algorithm optimally allocates the power with the lower Bit Error Rate (BER) of 0.00039 and better energy efficiency, spectral power, and achievable sum rate of 20.8134 J, 181.660 dB, and 110.615 dB, respectively. [ABSTRACT FROM AUTHOR]

This paper presents a novel energy balance scheme tailored for assessing energy efficiency in wastewater systems. It provides a consistent method to calculate the energy components associated with wastewater transport processes, allowing the quantification of the main water-energy inefficiencies. Three assessment levels are described (macro, meso and micro-level), depending on available information and scope. This balance allows a holistic approach of wastewater systems energy efficiency, including the system layout, losses in pipes/manholes, energy associated with undue inflows, exceedance volumes and energy recovery. The energy balance is applied to realcase studies. The energy associated with undue inflows represents from 20% to 44% of the external energy, with low average efficiencies of wastewater pumping systems (34%) and inflow intrinsic energy representing 64% of the total energy. This energy balance supports the performance diagnosis and the development of energy efficiency improvement measures. [ABSTRACT FROM AUTHOR]

Cell Formation (CF) and Group Layout (GL) are two important problems in designing a cellular manufacturing system. This article addresses an integrated CF and GL model as a mixed-integer program, considering energy consumption, assembly aspects and process routing. As a novel feature, machines are assumed to be capable of processing operations with different energy consumption rates and processing times. This model aims to determine concurrently machine cells, the layout of facilities (machines, workstations and cells), process routes and processing speed of operations so that the materials handling cost and the electric energy consumption are minimized. To demonstrate the applicability of the model, managerial insights are provided by a case study. Owing to the computational complexity of the problem, a hybrid solution approach combining a Genetic Algorithm (GA) and Simulated Annealing (SA) is proposed. The computational results demonstrate the superiority of the hybrid approach over CPLEX ® and conventional GAs and SA. [ABSTRACT FROM AUTHOR]

The Wireless Sensor Networks (WSNs) are mostly used for applications which hardly have human interaction and WSN is always known for its limited-energy issue. The wireless sensor nodes are equipped with an in-built power supply and have limited energy to complete their assigned tasks in WSNs. Therefore, for WSNs designing energy-efficient protocols is always been a challenging task for researchers. In this paper, we have studied and discussed various WSNs' existing protocols highlighting their merits and demerits. We have also made a comparative study on different parameters and methodologies followed by the respective references while designing different energy-efficient WSN protocols for different scenarios. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) enables the connection of physical objects to the internet for exchanging information. Due to the massive number of IoT devices, cellular traffic is increasing exponentially in wireless networks. IoT devices require low latency, high reliability and massive connectivity. Fifth Generation (5G) networks are expected to provide promising solutions to meet these demands and improve the performance of IoT systems. 5G offers low latency, high reliability, and efficient data transmissions for large number of connected IoT devices. IoT systems employ gateways for efficient connectivity of various devices. Gateways have capabilities of integrating various protocols, handling data storage temporarily, analyzing the data, and transmitting that data between edge devices and cloud. IoT devices transmit data in frequent intervals, causing the gateway to be active all the time, leading to the increase in power consumption of the gateways. In this article, we focus on applying Discontinuous Reception (DRX) mechanism to IoT gateways. The proposed DRX at IoT gateways reduces the power consumption and improves the energy efficiency of IoT gateways. Our proposed work improves the energy efficiency of gateways by almost 30% compared to Relay Energy Efficiency (REE) based scheme. [ABSTRACT FROM AUTHOR]

This paper proposes a hybrid suspension system, consisting of a linear electric motor (LM) and a semi-active mono-tubed magnetorheological damper (MRFD), to improve vehicle dynamics with lower power demand. For determining the damping force directly and concisely, a modified bi-viscosity magnetorheological fluid (MRF) model that explicitly includes the current parameter is developed. The fabricated LM and MRFD are calibrated and tested for validation of the implemented mathematical models. The simulation results show that the modified bi-viscosity model is able to calculate the experimental MRFD external forces very well. Thereafter, the hybrid suspension system is integrated into a 2-DOF (degree-of-freedom) quarter-vehicle dynamic model for simulation analysis, considering bump and pothole road profiles and the wheel bounce movements. Moreover, the two step-control methods, namely SC1 and SC2, are modelled for enhancing vibration mitigation and reducing power demand. The MRFD current influences on the root mean square (RMS) of the vehicle body vibration amplitudes are studied. Results reveal that the optimal MRFD current is ranged from 1 to 2.2A considering the SC1 method. Finally, the energy efficiency of the step-control methods is proved to be much higher than the PID method especially at low vehicle speed and in large road heave situations. [ABSTRACT FROM AUTHOR]

Capacity-building is acknowledged as an essential requirement for addressing environmental and developmental challenges in developing countries. In particular, the capacity to manage technological change is an important prerequisite for climate change mitigation, adaptation and green growth. Despite the importance of such capacity, there are surprisingly few empirical accounts unpacking its different dimensions and exploring how it might be built in developing countries in the context of climate and sustainable development challenges. In this paper, we contribute to this sparse literature through an in-depth qualitative case study on energy efficiency in India. Specifically, we take a systemic and evolutionary perspective to investigate how the Bureau of Energy Efficiency developed and implemented its programs to promote energy efficiency in household appliances, light-emitting-diode lamps and energy-intensive industries – and how in doing so, both drew upon existing capacity within and outside the country, and also built new capacity, to achieve significant energy savings. Key policy insights Since the capacity to manage technological change is distributed among a range of actors, policymakers require the ability to understand capacity needs from multiple actors' perspectives. Policymakers need to respond to evolving capacity needs over the course of a program – from strategic program design, trust-building and resource mobilization in early stages, to administration in later stages. 'System operators/integrators' can play a crucial role during the early stages of a program by helping develop capacity and sustaining it by creating a demand for such capacity, as well as bringing together actors, enabling coordination, and building coalitions among them. Preliminary analysis suggests that the Bureau of Energy Efficiency programs investigated in this paper resulted in significant energy savings and CO2 emission reductions. [ABSTRACT FROM AUTHOR]

The current paper aims to find scientifically valid approaches to improving the environmental safety of technologies for drying grain materials and granular fertilizers. The methodology for environmental and economic efficiency justification of the energy-saving multi-stage shelf dryers with a convective fluidized bed drying provides design and operational parameters control. Meta-analysis of energy-effective and eco-friendly dryers based on the bibliometric method and the Scopus database is used for this study. The results showed that pollutants concentration in the exhausts could be controlled by modifying the design and the required number of shelves, ensuring the required material residence time to achieve the desired moisture content. The production of electricity using alternative resources like biogas and biofertilizer produced from the anaerobic digestate allows for achieving several Sustainable Development Goals simultaneously. The Goals in scope include Goal 6 Clean Water and Sanitation, Goal 7 Affordable and Clean Energy, Goal 9 Industry, Innovation and Infrastructure, Goal 12 Responsible Consumption and Production, Goal 13 Climate Action, and Goal 15 Life On Land. [ABSTRACT FROM AUTHOR]

The major limitation of the use of superheated steam spray drying (SHS-SD) for food products is the missing proof of its applicability for heat sensitive materials. A selection of food, in particular dairy products, were spray dried under superheated steam conditions in a lab scale spray dyer with an inlet steam temperature of 250 °C and outlet steam and product temperatures between 130 and 160 °C by pressure nozzle atomization. Powder attributes show that superheated steam spray drying of heat sensitive food products is technically feasible and does not necessarily result in major quality loss such as severe browning. [ABSTRACT FROM AUTHOR]

Clay drying is one of the most important steps in the construction materials industry. Due to its high-energy requirement, clay drying is one of the most energy-consuming processes contributing to greenhouse gas emissions, motivating the search for strategies to increase the energy efficiency of the process. The process involves several operating variables whose historical records can generate a large amount of data, which can be organized and analyzed efficiently using data mining techniques (DMT). In this paper, the performance variables of a material-industry rotary dryer were identified and analyzed. A cluster analysis was performed using the Ward's classification method with 1729 operating data, identifying the kind of materials processed and the operating configurations. A linear regression model was constructed using the RRELIEFF feature selection algorithm in Orange: Data Mining Toolbox in Python. The main thermal-energy-consumption variables were the production rate, power, inlet gas temperature, and product moisture delta. These four variables represent the dryer's specific energy consumption index ( I c ) more suitably than the classic Energy Vs Production model. Consequently, it was established that a global-aeration-factor reduction could improve the process efficiency by 7% to 10% at the average production rate. [ABSTRACT FROM AUTHOR]

Industrial energy audit is one of the main strategies to improve energy efficiency. Usually, as an energy audit output, several improvement alternatives are provided. Choosing the best alternative has been detected as one of the main barriers in adopting energy efficiency projects. This work contributes to this decision-making process with a case study from an Argentine industrial plant. The project includes the installation of a micro-turbine within the steam system to generate electricity. To address the decision-making process, the historical records of steam system flows associated with energy consumption and costs were analysed. The project allows to reduce the annual energy consumption of the whole industrial plant by 6%. Furthermore, the investment needed for the project is recovered in around 4 years, and after a 10-year period, the project will refund more than 240,000$ plus the discount rate. The project reduces CO2 emissions by over 1000 tons per year. [ABSTRACT FROM AUTHOR]

A concept for a millimetre-wave (MMW) heat exchanger (HX) featuring AlN:Mo ceramic composite structures as electromagnetic absorbing elements (susceptors) has been recently introduced as a receiving device in power beaming applications. Earlier computational studies of electromagnetic and thermal processes have shown reasonable energy efficiency and exceptional uniformity of MMW-induced temperature fields in a single cubic susceptor with concentration of Mo doping on the level of 3–4% by volume. As part of ongoing research, a MMW HX comprised of an array of cylindrical susceptors is proposed to potentially enable increased robustness against thermal stress and reduced manufacturing cost. In this paper, we computationally study the effects driven by such a change and demonstrate feasibility of the designs based on multiple cylinders. We present the output of electromagnetic and coupled electromagnetic-thermal simulations of a prospective physical prototype of a HX with five cylinders on a square metal base plate. Three alternative layouts with four, nine, and sixteen cylindrical elements that are suggested by the highest density packing of equal circles in a square are also analyzed. It is shown that, in comparison with the previously studied case of a single cubic susceptor, energy efficiency of all systems with Mo = 3–4% is down from 50–55% to 35–45%. While temperature distribution within each individual cylinder remains highly uniform, maximum temperatures of different cylinders may be different by up to 30–40 °C; when the angle of incidence deviates from normal, this difference further increases: e.g. when the angle is 10°, in the sixteen-cylinder system, it may reach 120–130 °C. [ABSTRACT FROM AUTHOR]

Increasing data capacity requirements in cellular networks have raised the demand of low-cost and energy-efficient small cells to reduce the overall operating cost of the access network. This paper reports on the development of an energy-efficient and low-cost power amplifier design for TD-LTE outdoor pico base station. The proposed design of the power amplifier uses double-stage balanced configuration by exploiting the latest available process technologies on low-power devices and avoids commonly used a high-power LDMOS transistor. We examined the conceptual design of the power amplifier through ADS and SystemVue simulations and subsequently validated through practical implementation. The contribution of this paper is that the proposed design of pico base station operates at 12 V DC input supply rather than conventional −48 V which avoids the requirement of −48 V to 28 V DC–DC converter. As a result, the overall power efficiency of the proposed power amplifier for outdoor pico base station is increased by 2.7% in addition to the reduction of cost by 40%. Due to the light weight and small size, IP-65 compliant outdoor pico BS with proposed power amplifier can be contained in a single box. [ABSTRACT FROM AUTHOR]

Yerba mate is an herbal tea produced in the central part of South America. One of the main steps of the process is drying. Among the different types of dryers which are used at present, the double pass belt conveyer dryer is the most energy efficient. The increase in wood prizes used as fuel, has generated a demand from industrial producers to improve the thermal efficiency of the process. In order to do this, a numerical model of a double deck dryer of yerba mate has been developed to study the way of improving the energy efficiency and propose modifications to the present working conditions in industry. The good of fitness of the model was determined using experimental data from two industrial dryers. The results of the model were that using hot air at 100 °C and a solid mass flow rate of 4,000 kg/h, the energy efficiency was of 40.60%. Simulating the process at different drying conditions, it was found that the energy efficiency of the dryer could be improved by recirculating 15% of the exhaust air (63.70%), or drying at 120 °C and using a higher solids mass flow rate of 6,200 kg/h with an energy efficiency of 46.21%. [ABSTRACT FROM AUTHOR]

WSN consists of many sensors, they need high throughput and network lifetime to get involved in communication. Duty Cycle is a key factor in sensor nodes to maintain sleep, active condition in the presence of overhearing, collisions of packets while data transmission between sensor nodes. The key challenge of sensor nodes is to attain high energy efficiency, throughput and low End-End Delay. This paper presents several of existing approaches for MAC protocol. They are (1) Synchronization between nodes (2) Mathematical Analysis (3) TDMA based MAC and (4) Cross-Layer Design. We proposed a new method for MAC protocol with variable duty cycle. Neighboring nodes follow same duty cycle and same active time. Far away nodes doesn't maintain same duty cycle, hence their active time is not same. The duty cycle is maintained in synchronous way and adaptive manner among the nodes within the network. In this paper, a conventional MAC and proposed MAC are simulated using NS-2.35. Variable duty cycle approach in the proposed MAC with sleep and idle states for the nodes yields better throughput and energy efficiency with respect to other conventional technique. These results validate that the proposed variable DC-MAC is feasible for Wireless Sensor Network applications. [ABSTRACT FROM AUTHOR]

Fossil fuel firing heating systems will be substantially abandoned in the near future due to the zero-carbon goals. They will be replaced with heating systems that use renewable energy sources. Since the investment costs and area requirements of the renewable energy systems are high, the developments of highly efficient electric fluid heating systems have critical importance for a sustainable, environmentally friendly and clean heating. Among the electrical heating systems, induction heaters offer quite easy to use and better adaptability to most heating systems by allowing fluid heating without the necessity for contact. In this paper, a comprehensive review of the evolution of the induction fluid heaters is given by presenting the historical background. The most important milestones of induction fluid heating systems are presented. The development strategies suggested by the different papers including patents are investigated. The findings revealed that induction fluid heating systems, which reach approximately 100% thermal efficiency. These systems are introduced as follows: clean, non-emitting fluid heating system. Because of this, the study concludes that induction fluid heaters are one of the most promising alternatives to other electric heating systems in the long run. [ABSTRACT FROM AUTHOR]

This paper uses spatial econometric and the threshold effect models to study the effects of foreign direct investment (FDI) in China's energy conservation and emissions reduction. We use provincial-level data on pollutants (CO2, wastewater emission, exhaust emission, and waste emission) available from 2001 to 2015. Results indicated that FDI not only promotes China's "energy conservation," but also improves China's CO2 emission efficiency and environmental efficiency. We find that export-oriented foreign companies can significantly improve China's energy efficiency and water quality. FDI enhances energy efficiency through eco-oriented technological progress and water quality, air quality through production-oriented technological progress. We also find that the impact of FDI on China's energy conservation and emission reduction has significant threshold effects. Our findings contradict the often believed "pollution haven hypothesis." [ABSTRACT FROM AUTHOR]

A major barrier to the widespread adoption of energy efficiency is the lack of understanding of the benefits - the investment opportunity (the returns), the cost savings, and environmental. We assess the potential of retrofits in commercial buildings in Bangkok using case studies and existing property information. The aim is to provide insights for policy makers, building owners, and investors on the potential to reduce energy consumption and costs, and greenhouse gas emissions. Our findings suggest that by undertaking energy efficiency retrofits in Bangkok, there is the potential to reduce energy costs by approximately US123 million and reduce over 500,000 tons of CO2 emissions per year, presenting an investment opportunity of approximately US300 million, with a payback of 3.49 years. [ABSTRACT FROM AUTHOR]

Energy efficiency is one of the key aspects in energy transition, especially in building construction. One of the important things is also thermal comfort of the individuals. In this article, the design and the first results for the novel sensor device used to measure skin temperature are presented at two points used for purposes of estimating thermal comfort, a subjective feeling expressing the satisfaction with the thermal environment. [ABSTRACT FROM AUTHOR]