Resistive Heating Research Articles

Resistance Welding of Carbon Fiber Reinforced Vitrimer Composites

The welding behavior of prototype vitrimer composites with respect to adjustable parameters and protocols is investigated, and a method for resistance welding of vitrimer composites directly adapted from the welding of thermoplastic composites is described. Adherend laminates are positioned on either side of a matrix-saturated carbon fiber heating element, through which current is driven, and resistance heating welds the adherends and heating element together, forming a single lap joint. Weld strengths matched or exceeded the strength of composite parts produced using the manufacturer-recommended consolidation method (12.0 ± 2.6 MPa vs. 8.4 ± 0.6 MPa). Furthermore, repeating the welding process yielded greater shear strength, withstanding up to five weld–break–reweld cycles with an average increase of 4.6 ± 1.5 MPa or 65% compared to the first weld. The findings from resistance weld experiments highlight the suitability of vitrimer matrix composites for repair. Finally, a process for reversing a welded joint was shown, demonstrating the potential for vitrimers for temporary joining and rejoining.

Influence of half open coil structures on overall continuous induction heating of variable cross section pipe before quenching

Resistance heating of variable cross-section pipes before quenching can cause austenite grain coarsening, leading to inferior properties in thin-wall segments. This method also suffers from low heating efficiency, high energy consumption, and is time-consuming. This study compared the effects of variable cross section (VCS) and equal cross section (ECS) coil structures on overall continuous induction heating, aiming to investigate rapid and uniform heating solutions for this type of pipe. The results showed that the workpiece could be heated to the quenching temperature of 890 °C within 30 min using both coils. The ECS coil demonstrated superior heating efficiency, while the VCS coil exhibited better heating quality along the axial direction. Optimizations in VCS coil, including dynamic power control and insulation measures significantly improved the heating quality, with the final temperature distribution of the workpiece basically meeting the quenching requirements. Furthermore, an induction heating experiment was conducted to validate the reliability of the analysis model, showing good alignment with the simulated results. Overall, the application of half-open coil induction heating for variable cross-section pipes is feasible, offering a high efficiency and qualified heating quality. However, this technology is better suited for large-scale manufacturing, as each coil structure can only match one product specification; otherwise, it could significantly increase equipment costs. Additionally, for heating large workpieces, the workshop should have sufficient electrical load capacity to meet the power supply requirements.

Effects of Postweld Heat Treatment on Interfacial Behavior and Mechanical Properties of Joints Welded with Cu/Ni-Cr Alloy.

Welded cable composed of nickel-chromium (Ni-Cr) alloy and copper is a crucial component in the resistance heating technology used for heavy oil production. Tungsten inert gas (TIG) welding was employed to join the copper and Ni-Cr alloy using copper filler wire, and the stability of the welded joint was analyzed under high-temperature service conditions. We examined the changes in the microstructure and properties of the welded joint after postweld heat treatment (PWHT) at 600 °C for 3, 6, and 12 days. The results showed that the welded joint was appropriately formed, with fractures occurring in the copper substrate. The average tensile strength of the welded joint was 240 MPa. The copper and nickel dissolved into each other, forming a Cu0.81Ni0.19 strengthening phase. A columnar crystal diffusion layer formed at the interface between the Ni-Cr alloy and the fusion zone after welding. Grain boundary migration promoted the continuous growth in the columnar crystals as the PWHT duration increased, eliminating the microdefects and inhomogeneities caused by welding. The microhardness progressively decreased from the Ni-Cr alloy side to the copper side. However, the nanoindentation results at the Ni-Cr fusion line initially decreased and then increased with increasing PWHT duration, which contrasted the overall hardness trend observed across the joint after PWHT.

Improving Resistive Heating, Electrical and Thermal Properties of Graphene-Based Poly(Vinylidene Fluoride) Nanocomposites by Controlled 3D Printing.

This study developed a novel 3D-printable poly(vinylidene fluoride) (PVDF)-based nanocomposite incorporating 6 wt% graphene nanoplatelets (GNPs) with programmable characteristics for resistive heating applications. The results highlighted the significant effect of a controlled printing direction (longitudinal, diagonal, and transverse) on the electrical, thermal, Joule heating, and thermo-resistive properties of the printed structures. The 6 wt% GNP/PVDF nanocomposite exhibited a high electrical conductivity of 112 S·m-1 when printed in a longitudinal direction, which decreased significantly in other directions. The Joule heating tests confirmed the material's efficiency in resistive heating, with the maximum temperature reaching up to 65 °C under an applied low voltage of 2 V at a raster angle of printing of 0°, while the heating Tmax decreased stepwise with 10 °C at the 45° and the 90° printing directions. The repeatability of the Joule heating performance was verified through multiple heating and cooling cycles, demonstrating consistent maximum temperatures across several tests. The effect of sample thickness, controlled by the number of printed layers, was investigated, and the results underscore the advantages of programmable 3D printing orientation in thin layers for enhanced thermal stability, tailored electrical conductivity, and efficient Joule heating capabilities of 6 wt% GNP/PVDF composites, positioning them as promising candidates for next-generation 3D-printed electronic devices and self-heating applications.

Advanced Numerical Modeling and Experimental Analysis of Thermal Gradients in Gleeble Compression Configuration for 2017-T4 Aluminum Alloy

Gleeble thermomechanical simulators are widely utilized tools for the investigation of high-temperature deformation behavior in materials. However, temperature gradients that develop within the specimen during Gleeble compression tests have the potential to result in non-uniform deformation, which may subsequently impact the accuracy of the measured mechanical properties. This study presents an experimental and numerical investigation of the temperature fields in 2017-T4 aluminum alloy specimens prior to Gleeble compression tests at temperatures ranging from 300 °C to 500 °C utilizing uniform temperature distribution (ISO-T) tungsten carbide anvils. The use of multiple thermocouples, welded to both the specimen and anvils, offers valuable insights into the temperature gradients and their evolutions. A coupled thermal–electrical finite-element model was developed in Abaqus for the purpose of simulating the resistive heating process. A user amplitude subroutine (UAMP) is implemented to regulate the heating based on a proportional–integral–derivative (PID) algorithm that modulates the current density to follow the specified temperature profile. The numerical results demonstrate that the temperature gradients within the specimen at the end of the heating process, reaching a temperature of 400 °C, are minimal, with values below 1.9 °C. This is in accordance with the experimental observations. The addition of graphite foils between the specimen and anvils has been shown to effectively reduce the gradients. The use of the measured anvil temperature as a boundary condition, rather than a constant value of 20 °C, has been demonstrated to improve the agreement between the simulated and experimental cooling curves. The modeling approach provides a framework for quantifying temperature gradients in Gleeble compression specimens and for assessing their impact on the measured constitutive response of materials at elevated temperatures.

Comparing Feature and Trajectory-Based Remaining Useful Life Modeling of Electrical Resistance Heating Wires

Industrial heating significantly contributes to global greenhouse gas emissions, accounting for a substantial portion of annual emissions. The transition to fossil-free operations in the heating industry is closely linked to advancements in industrial electrical heating systems, especially those using resistance heating wires. In this context, Prognostics and Health Management is crucial for enhancing system reliability and sustainability through predictive maintenance strategies. The integration of machine learning technologies into Prognostics and Health Management has significantly improved the precision and applicability of Remaining Useful Life modeling. This improvement enables more accurate predictions of component lifespans, optimizes maintenance schedules, and enhances operational efficiency in industrial heating applications. These developments are essential for reducing greenhouse gas emissions in the sector. This paper serves as a guide for conducting Remaining Useful Life modeling for industrial batch processes. It evaluates and compares two methodologies: deep learning-based approaches using full time-series data, such as recurrent neural networks and their variants, and feature-engineering-based methods, including random forest regression and support vector machines. Our results show that the feature-oriented approach performs better overall in terms of predictive accuracy and computational efficiency. The study includes a detailed sensitivity analysis and hyperparameter estimation for each method, providing valuable insights into developing robust and transparent Prognostics and Health Management systems. These systems are crucial in supporting the heating industry’s move towards more sustainable and emission-free operations. The findings reveal that feature-oriented methods are both performant and robust, particularly excelling in handling outliers. The random forest regression model, in particular, demonstrated the highest performance on the test dataset according to the chosen evaluation metrics. Conversely, trajectory-oriented methods exhibited less bias across varying levels of degradation, a helpful characteristic for Prognostics and Health Management systems. While feature-oriented methods tend to systematically underestimate Remaining Useful Life at high true values and overestimate it at low actual values, this issue is less pronounced in trajectory-oriented models. Overall, these insights highlight the strengths and limitations of each approach, guiding the development of more effective and reliable predictive maintenance strategies.

Resistive Heating and Thermal Decomposition of an Additively Manufacturable Electrically Conductive Explosive

AbstractThe ability to transmit electrical signals through high explosive charges without using dense metal conductors could enable continuous monitoring of explosive charges with internally embedded sensors. With the sensor materials themselves being energetic, the impact on the intended detonation performance of the charge can be minimized. Embedded sensors enable real time, in‐situ measurements of conditions relevant to ageing assessments. Additionally, dynamic material property sensing can provide detonation performance data, enabling measurement of dynamic shock position. One proposed method to allow for electronic signal transfer through high explosives is to use electrically conductive explosive composites consisting of an electrically conductive polymer binder mixed with high explosive crystals. These conductive energetic pathways also serve as independently reactive elements and can provide additional functionality via dynamic sensor removal through resistive heating and subsequent decomposition. This work discusses the resistive heating of a previously developed, poly (3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based, electrically conductive extrudable explosive composite. Experimental samples of the conductive explosive material were subjected to a range of direct current applications and the resulting heating and decomposition of the material is discussed.

Hybrid heating in the fused filament fabrication process

AbstractAltering the heating regime of the polymer during the fused filament fabrication (FFF) process can lead to changes in both the behaviour of the polymer and the characteristics of the printed product. This study proposes replacing the traditional resistive heating system with two hybrid systems that introduce an additional temperature of 120–160 °C: one combining resistive and hot air jet heating, and the other combining resistive and infrared radiation heating. The samples printed using these hybrid systems were analysed using differential scanning calorimetry (DSC) and visually inspected. Commercial ABS and PLA filaments were used in the experimental programme. A model to evaluate the polymer’s melting during the printing process was proposed and experimentally validated. Visual testing revealed that the printed lattice structure had smaller voids, characterised by depositions that were flattened rather than circular in cross-section due to the extended time in a viscous/partially molten state. The elongation viscosity and storage modulus decreased by approximately 10%, with a slightly smaller decrease observed for the infrared radiation heat source. The glass transition temperature remained unchanged, and the molecular mobility was not affected by the additional heat. Similarly, the energy required for crystal formation was unaffected by the supplementary heat. The mechanical behaviour of the printed pieces during compression tests was also influenced by the addition of a second heat source. For both materials, a decrease in deformability was observed as the temperature of the hot air jet increased.

Conjugate direct resistance heating of metallic plates. multiplicities and stability

A numerical bifurcation analysis is presented for an industrial application where direct resistance heating through a DC is applied to a flat metallic plate, which is cooled by a turbulent boundary layer and radiation. The process is modeled with a conjugate heat transfer between the plate and the cooling air steam. The convective part of the heat transfer mechanism is formulated in the framework of an integral approach, considering a turbulent core based on power law velocity and temperature profiles and a thin laminar sublayer thermally coupled with axial conduction along the plate. The analysis reveals that the problem admits two solutions: one stable and one unstable, separated by a limit point. The existence of multiple solutions is a consequence of the nonlinear electric resistivity–temperature relationship, allowing thermal equilibrium between heat generation and heat dissipation in multiple points. The application of realistic boundary conditions at the wall–fluid interface shows that the thermal to the hydrodynamic boundary layer thicknesses ratio along the plate is no longer close to the value of 1.25, as it is the case with a constant wall temperature. Instead, significant deviations occur due to the thermal coupling between the wall and the cooling fluid. The multiplicity structure and, consequently, the limit points depend on the plate Reynolds number and on the conduction–convection parameter. The locus of the limit points defines an instability threshold beyond which any excess applied current will trigger a thermal runaway phenomenon. This is also an equivalent of the maximum current carrying capacity of the plate.

Coal-derived electrically conductive asphalt pavements for snow/ice melting: From laboratory to field

Timely removal of ice and snow from roads is critical to safe, fast, and uninterrupted transportation networks in cold regions. Constructing electrically conductive asphalt pavements to melt the ice and snow on the roads through resistive heating is an emerging alternative technology to traditional snow/ice removal approaches such as utilizing snowplow machines and deicing chemicals. Carbon-based fibers and fillers including carbon fiber and graphite have been widely reported to make electrically conductive hot mix asphalt mixtures for pavement snow/ice-melting applications. This study aimed to develop and demonstrate a novel type of electrically conductive asphalt pavements for snow/ice-melting, which utilizes electrically conductive cold mix asphalt (CMA) mixtures incorporating coal-derived carbon-based coke aggregate as resistive heating elements. Both laboratory experiments and field tests were conducted to investigate the electrical, mechanical, and thermal properties of such electrically conductive asphalt mixtures and pavements. The laboratory experiment results indicated that the electrically conductive CMA mixtures incorporating coke aggregate had sufficiently high electrical conductivity and satisfactory mechanical performance and the pavement prototype slab utilizing a thin layer of such CMA mixtures could successfully raise the pavement surface temperatures to 8.3–11.7 °C from a low temperature of −5 °C with an input power density of 473 W/m2. The field test results showed that the full-scale coal-derived electrically conductive asphalt pavements were able to increase the pavement surface temperatures when electricity was applied, but the magnitude of temperature increase was highly dependent on the power density. Therefore, it is promising to use coke aggregate to construct coal-derived electrically conductive asphalt pavements for snow/ice melting.

Determination of the possibility of using a functional apparatus for the production of multi-component semi-finished products with a high degree of readiness

The object of research is a functional apparatus for the production of paste-like and powdered vegetable semi-finished products. The problem of combined heat and mass exchange treatment of vegetable raw materials are solved by using a functional apparatus for concentration and drying for processing and production complexes, farm lands. The expected effect during the approbation of the device is predicted under the condition of a functional approach combining the processes of concentration and drying with precise control of the temperature regime due to the use of a film-like resistive electronic heater of the radiating type. In the study, the approbation of a functional device for the production of multi-component vegetable semi-finished products of a high degree of readiness, with concentration and drying in the field of infrared heating at a temperature of 50 °C, was performed. Real-time temperature measurement was carried out by an automatic unit based on TRM, which ensured the accuracy of control at each stage. The temperature of the mashed mass during processing increased from 20.3 °С to 23.2 °С, reaching optimal conditions for forming a film with a thickness of 0.5 mm. In the rotary reboiler, the temperature in height varied from 25.7 °C to 50.1 °C, which contributed to the preservation of the properties of thermolabile raw materials. In the lower part of the apparatus, the temperature of the finished product was 49.8 °C, maintaining the necessary temperature regime for drying. The device creates a convective air flow (0.01 m/s) with the help of Peltier elements, which stabilizes the heat exchange at a temperature of 51.3 °C on the technical partition. The practical use of the functional apparatus will allow its use at processing and production complexes and directly at the places of collection of plant raw materials for resource-efficient production of semi-finished products with a high degree of readiness. These semi-finished products can act as independent functional products for people in extreme conditions or as recipe ingredients for the recipes of various food products.

Silicon Microthermocycler for Point-of-Care Analytical Systems: Modeling, Design, and Fabrication.

A four-tether silicon microthermocycler for point-of-care PCR analytical systems is proposed. Substituting the commonly employed platinum with titanium in the fabrication of thin film resistance temperature detectors and heaters enabled the realization of a smaller device without compromising temperature accuracy or increasing heater lead power losses. The device was extensively analyzed through analytical modeling and FEM numerical simulations using a 3-D thermo-mechanical simulation model in COMSOL. Numerical simulations revealed that the four-tether design provides a 460% improvement in mechanical strength and a 57% reduction in the thermal time constant compared with a similar three-tether design, with a trade-off of a 22% increase in heat losses. Detailed structural and thermal analyses of crucial design parameters guided the optimization of the final geometry, leading to the successful fabrication of prototypes. It was shown that the current of 60 mA was sufficient to heat the fabricated solid and hollow silicon structure to 132 °C and 134 °C in 10 s for an applied heater power of 510 mW and 525 mW, respectively.

Experimental study on heat transfer characteristics of pulsating heat pipe under vibration environment

Understanding the heat transfer characteristics of pulsating heat pipe (PHP) under vibration condition is important for the specific applications of PHP in moving vehicles, working machines or handheld equipment. In this paper, an experimental system for testing the thermal performance of PHP under different vibration conditions was built, the effects of vibration frequency and vibration amplitude on the temperature oscillation characteristics, overall heat transfer performance (thermal resistance and equivalent heat conductivity), start-up performance (start-up temperature and start-up time) of PHP have been analyzed. The results show that more obvious influences of vibration frequency and amplitude on the heat transfer performance of PHP can be observed under lower heat input condition. Increasing vibration frequency will reduce the overall thermal resistance, start-up time and start-up temperature, and increase equivalent heat conductivity. However, increasing vibration amplitude will enhance the overall thermal resistance and reduce the equivalent thermal conductivity, and increase both start-up time and start-up temperature. Therefore, better heat transfer performance of PHP can be obtained under high-frequency vibration environment or small amplitude vibration environment, as well as the start-up performance. It is acknowledged that compared with non-vibration condition, the heat transfer performance of PHP is limited under low vibration frequency (fv ≤ 25Hz) or large vibration amplitude (a ≥0.8 mm).

Engineering morphological architecture of superhydrophobic/hydrophilic composite membrane for efficient photothermal membrane distillation

The viability and efficacy of photothermal membrane distillation (PMD) is still uncertain due to its inherent energy-efficiency and throughput mass flux limitation. Herein, we develop a delamination-free multilayer photothermal membrane that simultaneously imparts slashed mass transfer resistance, enhanced photothermal effect and strong water-repellency by engineering morphological architecture. Using a one-step programmed dual-channel electrospinning followed by an electrostatic spraying technique, the proposed membrane is composited by a thick water-intrudable hydrophilic supporting layer, a thin hydrophobic layer, and an ultrathin Ti3C2Tx MXene-engineered superhydrophobic layer. It is proposed that the morphological architecture engineering could render mitigation of mass transfer resistance, firm water-repellency, and robust heat localization. Hence, in addition to superior flux of 1.27 L m−2 h−1 (inlet feed/permeate at 20/20 °C) and 15.89 L m−2 h−1 (inlet feed/permeate at 50/20 °C), prominent solar efficiency (76.34 % and 96.45 %) of the proposed composite membrane (DS15-M) also was achieved during PMD operation (1.0 kW m−2). Moreover, the DS15-M showcased not only robust wetting resistance and long-term consistency, but also obviously mitigated temperature polarization effect during the PMD operation. This research work emphasizes the important role of morphological architecture in rendering performance enhancement, which is a significant implication in engineering membrane architecture for PMD application.

Conductive Polyethylene/Polyester Textiles with Temperature‐Strengthened Electromagnetic Interference Shielding Efficiency

The advancement of electromagnetic interference (EMI) shielding materials provides reliable protection for the communication technology. However, the performance of conventional EMI shielding materials is significantly diminished in high‐temperature conditions. Herein, an efficient method is proposed to prepare conductive fabrics with temperature‐strengthened EMI shielding performance via chemical plating technique. The as‐prepared polyethylene/polyester‐metallized fabric (PMF) coated with Ni–W–P alloy exhibits outstanding EMI shielding effectiveness (SE) in X band, which is strengthened from 16 to 59 dB with temperature raising from room temperature to 130 °C. Particularly, the corresponding temperature‐strengthened shielding behaviors are investigated through simulations in Computer Simulation Technology. Additionally, PMF presents excellent corrosion resistance (corrosion voltage [Ecoor] of −0.324 V and corrosion current [Icoor] of −6.760 A·cm−2) and admirable Joule heating performance, reaching maximum temperature of 74 °C at only 1.5 V. Therefore, the as‐prepared PMF endows enormous potential in EMI protection under high temperature and harsh environments.

Comparison with Carnot battery of an alternate thermal electricity storage charged by concentrated photovoltaic thermal system and resistance heater

In Carnot Batteries (pumped thermal electricity storage), which is known as a low-cost electricity storage method, electrical energy is stored as thermal energy and then converted back into electrical energy using a heat pump and a heat engine, respectively. In the studies carried out to date, different heat source scenarios, heat storage methods, and methods to improve heat pump and heat engine cycles have been applied to increase efficiency and reduce the cost of the Carnot Battery. This study’s novelty was using a concentrated photovoltaic thermal system and resistance heaters instead of a heat pump for the charge cycle in thermal electricity storage. This novel thermal electricity storage design aimed to reduce the levelized cost of storage of the system by eliminating the need for a heat pump and reducing the volume of the water storage tank. First, parametric analyses were performed for the specific variables of both energy storage systems. Afterward, the Carnot Battery and the proposed system were compared for the same electricity storage capacity. For charge/discharge times ranging from 4 h to 8 h and electricity storage capacities ranging from 0.5 MW to 2 MW, a 31.8 % to 58 % increase in round-trip efficiency and a 7.13 % to 20.67 % decrease in levelized cost of energy storage were achieved with the novel design.

Interaction of liquid titanium with zirconates and titanates of some alkaline earth metals

Abstract The article presents the results of a study of the interaction of titanium melt with of zirconates BaZrO3 and SrZrO3, as well as titanate SrTiO3 under vacuum conditions and in an inert atmosphere at normal pressure. An original titanium heating method was used during the experiments. It eliminated the melt circulation at the interface between the solid and liquid phases. The method was based on resistive electrical heating of a Grade 2 titanium alloy rod or strip pressed into BaZrO3, SrZrO3 and SrTiO3 powders. Studied the structure, elemental, and phase composition of the products formed during various (up to 300 s) contact of titanium melt with surface zirconates and titaniums. The phase composition was compared with the products obtained by heating compacts from a mixture of titanium powders with BaZrO3, SrZrO3 and SrTiO3 powders. It was shown based on the results obtained that titanium, upon contact with these ceramic materials dissolves zirconium and oxygen and reduces barium and strontium to a metallic state. Barium and strontium evaporated due to the high vapor pressure at the experimental temperature, and caused the melt to splash or form a vapor layer that reduced the interaction rate of the melt with the ceramic. When a titanium melt interacted with BaZrO3 and SrZrO3 intermediate phases were not formed in quantities sufficient for their identification. The Sr3Zr2O7 phase was formed in small quantities during heating a mixture of Ti+SrZrO3 powders. When a titanium melt interacted with SrTiO3, a layer of an intermediate phase was formed, similar in composition to TiO2. Equations for the chemical reaction of the interaction of titanium with the indicated zirconates and titanate were compiled based on the experimental data obtained. It has been shown that titanium melt weted the surface of BaZrO3, SrZrO3 powders well and poorly weted the surface of SrTiO3 powder.

Fast-airflow tumble clothes dryer with small thermoelectric heat pump: Experimental evaluation

Residential clothes drying accounts for about 5 % of the total residential-sector energy consumption in the United States. Most dryers use electric resistance heaters to dry clothes and have low efficiencies. Higher-efficiency dryers that use vapor compression heat pumps are expensive and complex and have not gained a large market share in the United States. A novel tumble clothes dryer using a small thermoelectric heat pump with faster airflow than typical dryers is presented in this work. The benchtop performance of the thermoelectric heat pump and high-speed blower are presented, and the development of the prototype dryer is described. The dryer was tested for efficiency and dry time for a range of airflow rates and applied currents to the thermoelectric heat pump. The combined efficiency factor was 5.09–6.29 lbBDW/kWh (specific moisture extraction rate of 1.23–1.53 kgw/kWh) with 100–138 min dry times for these tests. The measured efficiency was 36 %–68 % greater than the minimum efficiency standard in the United States, and compared with vapor compression heat pump–based clothes dryers, the prototype dryer had less expensive, less complex components and did not use refrigerants. The performance of this small thermoelectric heat pump clothes dryer is also compared with previous iterations of the thermoelectric tumble clothes dryer described in the literature.

Experimental study of four-step thermal swing adsorption cycle to upgrade biogas obtained from anaerobic digestion

Biogas is a renewable source of energy that when upgraded can be adopted as a reliable and sustainable alternative. This study evaluates the performance of thermal swing adsorption technology applying resistive heating, in upgrading biogas obtained from anaerobic digestion to biomethane. Commercial coconut shell-based activated carbon was used as an adsorbent in the four-step cycle process to capture carbon dioxide, using a fabricated adsorption model. The influence of minor gas constituents of biogas in carbon dioxide breakthrough curves was analyzed. Dynamic adsorption tests were carried out to evaluate the system performance in carbon dioxide capture. The maximum regeneration temperature of 60 ℃ was found to have peak carbon dioxide concentration of 39% in the waste gas, maximum energy requirements of 0.1538kWh per cycle, and an energy efficiency of 87%. This is a good trade-off between adsorbent recovery and system energy efficiency. The adoption of thermal swing adsorption technology in biogas upgrading systems is a viable alternative for water-deficient regions.

Food Production in Ergonomically Designed Unit with Low Energy Consuming Thick Film Hot Plate

The Trans-Himalayan region of Ladakh is a cold desert where the temperature drops as low as -45°C, which makes the cultivation of fresh food almost impossible. The region is strategically very important as it borders two countries China and Pakistan. The unavailability of fresh food causes nutritional deficiency in the deployed troops and locals, affecting their performance. Cultivation of fresh food is very difficult due to the average low temperature and mountainous soil of the region. Transportation of fresh food to such forward locations causes decaying of nutrition besides the difficulty of reaching such snow-bound mountainous locations. Nutritious micro-greens grown in media under controlled conditions look perfect solutions for meeting nutritional requirements. The present study focuses on year-round cultivation of nutritious micro-green (2-3 times more nutritious than mature counterparts) with low energy consuming thick-film hot plate for necessary temperature maintenance in properly designed portable structures to reduce dependency on packaged food which are the causes of many diseases. The study involves the development of a thick film energy-efficient micro-climate maintenance technology-based system for the maintenance of temperature along with phase-wise development of suitable cultivation structure and standardization of the number of such plates and sizing of the portable unit.These hotplates produce heat based on the principle of Joule heating or resistive heating and the power of a hotplate is equal to I2R. The hotplates are capable of raising the surface temperature to 90°C –100°C at the expense of only 8W power consumption and maintenance of average temperature in the range of 18°C to 20°C at -25°C to -40°C outside ambient temperature. The region receives the highest solar irradiance along with annual average of 7-8 hours of sunshine duration and hence a solar-based technology can fulfill the energy supply of 8W with ease.The study revealed that a suitable temperature can be maintained for growing variety of nutritious micro-green in a triple layer-based multitier structure integrated with low energy consuming (~8 W), small (50.8 mm (x) 50.8 mm), efficient, and lightweight thick film technology.Thick-film hot plate integrated standardized unit is capable of producing an average of 1000grams/trial/unit in a short period of 8-12 days during the winter period of 6-8 months for the targeted supply of 8-10grams/person/day with total energy consumption of approximately 20-25Kw/trial at ~3350 m to ~5400 m Altitude.