Conventional Heating Method Research Articles

INSTALLATION OF SOLAR-POWERED ELECTRIC WARMERS FOR DOC-BROODING IN BLITAR CHICKEN FARMERS

Community Service (PPM) is held in Sumberejo Village, Sanankulon District, Blitar Regency. Chicken farmers face several challenges related to heating their chicken coops, including restrictions on using subsidized fuel or LPG, which force them to seek other heating alternatives. Leaks in heating systems that use LPG, which pose a fire hazard. Poor air quality and low oxygen levels in coops that use conventional heating methods (firewood and LPG). These challenges can contribute to the decline in the quality of Day-Old Chicks (DOC). This activity aims to install an electric warmer system that produces a safe and comfortable temperature for Day-Old Chicks (DOC) and is easy to use for breeders. In addition, build an independent energy source to run the heat treatment system equipment in the DOC-Brooding area with a solar panel installation. The installed 600 Wp PLTS system consists of 4 solar panels with a capacity of 150 Wp each, an 850 VA hybrid inverter and 100 Ah VRLA battery. Electrical energy from PLTS can power a 200 W electric warmer. The solar panel installations can produce an average of 3.6 kWh of electrical energy/day. So that the electricity savings from PLN can reach IDR. 162000 per month.

Energy, economic, and environmental evaluation of a GAX-based cross-type absorption-resorption heat pump

Thermally driven absorption heat pump is regarded as one of the most promising methods to efficiently utilize low-grade heat, reduce energy consumption and greenhouse gas emissions. However, there are still limitations when using it at low ambient temperature in cold regions, and its application is limited by their low system performance. In this study, we proposed a novel Generator-absorber heat exchange (GAX) based NH3/H2O cross-type absorption-resorption heat pump driven by waste flue gas, which amalgamates the absorption-resorption and GAX cycles, yielding a dual advantage of diminished heat source temperature and operating pressure requirements. Additionally, it substantively enhances the system's performance by capitalizing on the cross-type solution cycle integration. A mathematical model has been developed and the results have been compared and validated with those reported in the literature. The proposed system is comprehensively studied from the view of energy, exergy, economic and environmental (4E) analysis to determine its advantages and disadvantages. The results reveal that the proposed system achieves a maximum COP of 2.742 under specific operating conditions, which is 82.8% higher than the conventional absorption heat pump (AHP), and 30.57% higher than the conventional GAX-AHP. Besides, the addition of a compressor can significantly enhance the performance of the system at lower driving heat source temperatures. At a PH/PL pair of 1.7/0.47 MPa, the static payback period is 4.113 years, with the heating capacity of 88.51 kW and the supply water temperature of 54.6 °C, showcasing favorable system performance. Furthermore, the total atmospheric pollutant emissions could be reduced by 30,998 kg/year compared to the conventional heating method.

Ultrasonic Assisted Three Component Synthesis of 3-Cyano-pyridine-2(1H)-ones

The requirements of sustainability and the green chemistry principles have prompted organic chemistry researchers to come up with novel methods for the synthesis of organic compounds that require minimum energy consumption and pose lesser environment harm. Ultrasonication of reaction mixtures is one such methodology. High frequency sound waves are known to emit energy that is utilized in product generation. Attempts were made to synthesize 2-pyridone derivatives using ultrasonication assisted method of synthesizing 3-cyano-pyridine-2(1H)-one starting from a three component one pot reaction. The reaction between cyanoacetamide, aromatic ketones and substituted aromatic aldehydes in the presence of NaOH as base yielded 4,6-diaryl-2-oxo-1,2-dihydropyridine-3-carbonitrile derivatives as a result of one-pot multicomponent reaction. The synthesized 4,6-diaryl-2-oxo-1,2-dihydropyridine-3-carbonitrile derivatives were characterized by 1H NMR, 13C NMR, HRMS and FTIR spectra. Ultrasonication has been found to significantly reduce reaction time, enhance reaction rate and yield compared to conventional heating methods.

Ionic liquid mediated synthesis, molecular docking study and anticancer activity of 5-((3-aryl-1-phenyl-1h-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-ones

A series of 5-((3-Aryl-1-phenyl-1H-pyrazol-4-yl)methylene)-2-thioxothiazolidin-4-ones were synthesised by the Claisen-Schmidt condensation of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde with 2-thioxothiazolidin-4-one using Ionic liquid under both conventional heating method and microwave irradiation method. All the synthesised derivatives were screened for their anticancer activity against three different human cell lines as cervix (SiHa), brest (MDA-MB-231) and pancreatic carcinoma (PANC-1) using the Sulforhodamine B assay method and studied their molecular docking analysis.

The Effect of Ohmic Heating on the Quality Properties of Couscous during Cooking

Couscous has been widely eaten around the world because it has a low glycemic index, is low in fat, and is simple to prepare. However, it should be cooked before consumption. Therefore, novel heating methods, such as ohmic heating, can be used to cook couscous. This study aimed to investigate the potential use of ohmic heating at a voltage gradient of 17 V/cm to cook couscous and compare it with the conventional cooking method. To determine the effect of ohmic heating and conventional methods on the quality properties (color, texture profile analysis, cooking loss, moisture content, and weight increase (%)) of couscous, samples were cooked in a 0.1% salt solution. The samples were analyzed at different cooking times (4, 8, 12, and 16 min). The results obtained in the present study revealed that the total color difference also increased with an increase in cooking time. In addition, similar trends were observed for cooking loss, moisture content, and weight gain. Furthermore, the couscous samples treated with ohmic heating and conventional heating methods were completely cooked after 12 minutes. Overall, compared to the conventional cooking method, the ohmic heating process did not induce any negative effects on the quality parameters of couscous.

Comparing Heat-Induced Antigen Retrieval Methods for ER Expression in Invasive Breast Carcinoma

In the realm of cancer diagnosis and treatment, immuno-histochemical staining has become a pivotal tool for discerning molecular markers within tissue samples. Objective: To comprehensively compare different heat-induced antigen retrieval methods for evaluating estrogen receptor (ER) expression in female invasive breast carcinoma of no special type. Methods: A cross-sectional design was employed utilizing 250 formalin-fixed paraffin-embedded (FFPE) tissue samples from confirmed cases of invasive breast carcinoma. The study was conducted within Histopathology Department in CMH Peshawar. The study spanned from January 6, 2022 to June 30, 2023. Three heat-induced antigen retrieval methods were evaluated: conventional microwave-based retrieval, pressure cooking retrieval, and water bath heating. ER expression was assessed through immune-histo-chemical staining, and scores were analyzed using descriptive statistics and ANOVA. A post hoc Tukey's Honestly Significant Difference (HSD) test was conducted to identify which specific retrieval methods exhibited significant differences in ER expression scores. Results: The pressure-cooking retrieval method exhibited significantly higher mean ER expression scores (7.52) compared to the conventional microwave-based (6.87) and water bath heating methods (6.65). Post hoc analysis confirmed the substantial differences. Standard deviations and interquartile ranges were consistent with each method. Conclusions: The study underscores the pivotal role of retrieval techniques in accurate ER expression assessment in female invasive breast carcinoma of no special type. The pressure cooking method emerges as a potent enhancer of ER expression, advocating for standardized protocols to ensure consistent diagnostic outcomes and informed therapeutic decisions. Despite limitations, this research contributes to the refinement of patient care in the management of invasive breast carcinoma.

Programmable heating and quenching for enhancing coal pyrolysis tar yield: A ReaxFF molecular dynamics study

In this paper, the impact of the programmable heating and quenching (PHQ) method on coal pyrolysis tar yield was investigated via ReaxFF molecular dynamics method. Firstly, thermostatic pyrolysis simulations of coal were performed to determine the range of maximum (Tmax) and minimum (Tmin) temperatures for the PHQ method. Then, the effects of the ratio of heating time (th) and cooling time (tc), Tmax, and Tmin on pyrolysis tar yield were investigated. The results showed that reducing th/tc, Tmax, and Tmin helped to improve tar yield. Finally, the effects upon pyrolysis products were compared between the conventional continuous heating (CCH) method and the PHQ method. It was revealed that 37.67 % increase in tar yield was achieved with the PHQ method compared to the CCH method. The main basic reactions during coal pyrolysis were analyzed to reveal the mechanism of the PHQ method on tar yield. There were three ways to increase tar yield with the PHQ method: (1) the elevated production of OH radicals during each heating stage facilitated the decomposition of char into tar; (2) the reduction of temperature during each quenching stage hindered the condensation reactions among tar molecules; (3) the reactivity of the tar was also diminished.

Effect of microwave method on jasminaldehyde synthesis using solvent-free over Mg–Al–NO3 hydrotalcite catalyst

Jasminaldehyde is a widely used starting material in the chemical industry. One method for synthesizing jasminaldehyde is through the aldol condensation of benzaldehyde with 1–heptanal, using a heterogeneous catalyst called hydrotalcite Mg–Al–NO3. The synthesized catalyst was characterized using various techniques, including XRD, FT–IR, TGA, DTA, SEM, EDX, and N2 adsorption–desorption isotherm (BET) to determine its structure, morphology, thermal stability, and properties. This catalyst was tested in the studied reaction under solvent-free conditions, using both microwave and conventional heating methods (in an oil bath) to evaluate the efficiency of each method in producing jasminaldehyde. The results showed that the use of microwave heating in this reaction is particularly advantageous. It allowed for the highest conversion (>99%) of 1–heptanal, with a good selectivity (80%) towards jasminaldehyde, after only 50 min of reaction time. In contrast, conventional heating required a longer reaction time of about 8 h to achieve similar conversion and selectivity values. Furthermore, Mg–Al–NO3 demonstrated nearly sustained activity in three consecutive reuse experiments, and the durability of this catalyst was characterized using several techniques.

Microwave assisted glycerol esterification using CeO2, ZrO2, mixed metal oxide catalyst

Present study focuses on the up-cycling of glycerol by esterification reaction using acetic acid to produce acetins. Heterogeneous catalysts such as CeO2, ZrO2 (commercially procured) and CeO2-ZrO2 mixed metal oxide catalysts synthesized using solution combustion method were used to synthesize acetins. The reactions were performed in a microwave reactor at a power level of 900 W, which rendered the reactions faster and simpler compared to the conventional heating method. The effect of temperature (80 °C, 90 °C, 100 °C), the initial molar ratio of glycerol: acetic acid (1:5, 1:10, 1:15) and the amount of catalyst (3 wt%,5 wt%,7 wt%) were studied for all the three catalysts. The study showed a rapid phase of reaction for up to 30 min and then the reaction proceeded at a constant rate. The conversion was higher at 100˚C. Rate constants determined from kinetic model was increasing with temperature. The kinetic data was observed to best fit the pseudo-first-order kinetic model. The study has demonstrated an efficient way of synthesizing acetins in presence of metal oxides by the application of microwave heating as process intensification technology.

Ionic Liquid Mediated Synthesis and Anticancer Activity of 5-((1, 3-DIPHENYL-1H-PYRAZOL-4-YL) METHYLENE) THIAZOLIDINE-2, 4-DIONES

Abstract: A series of 5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)thiazolidine-2,4-dione derivatives were synthesised by the Claisen-Schmidt condensation of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde with thiazolidine-2,4-dione using Ionic liquid under both conventional heating method and microwave irradiation method. All the synthesised derivatives were screened for their anticancer activity against three different human cell lines as cervix (SiHa), brest (MDA-MB-231) and pancreatic carcinoma (PANC-1) using the Sulforhodamine B assay method.

A Comprehensive Review in Microwave Pyrolysis of Biomass, Syngas Production and Utilisation

Lignocellulosic and waste materials, such as sewage sludge, can be broken down into its useful constituents and converted into fuel for engines. This paper investigates microwave pyrolysis to decompose biomass into H2 and CO (syngas), which may be catalysed in the Fischer–Tropsch (F-T) process to liquid biofuels. Using microwave radiation as the heat source for pyrolysis proves to yield large quantities of gas with higher concentrations of H2 and CO compared to conventional heating methods. This is largely due to the energy transfer mechanism of microwaves. Pyrolysis parameters such as temperature (which increases with input power), feedstock type, microwave absorber, and biomass moisture content influence syngas yield. Several papers reviewed for this study showed differing optimal conditions for microwave pyrolysis, all being heavily dependent on the biomass used and its composition. However, all researchers agreed on the thermal efficiency of microwave heating and how its material-selective nature can increase syngas yield. Compared to diesel fuels (while processing a similar efficiency and a higher cetane number), FT fuels and specifically pyrolysis may yield the benefit of reduced nitric oxides (NOx), particulate matter (PM), unburnt hydrocarbons (HC) and carbon monoxide (CO) emissions.

Innovative date syrup processing with ohmic heating technology: Physiochemical characteristics, yield optimization, and sensory attributes

The present study aimed to investigate the application of the ohmic heating (OH) technique in the production of date syrup from the date fruit of the Sukkary variety at different electric field strengths (EFS) (9, 10, and 11 V/cm). The results were compared to the conventional heating method (CH). The response surface methodology was used to optimize yield. The results showed that the time to reach the boiling point of dates and water mixture using OH was less than the CH by 80% for extracting and 900% for evaporation. In addition, the productivity of date syrup using OH at EFS of 11 V/cm was higher than the CH by 86.11%. There is no significant effect between OH at EFS of 11 V/cm and CH in moisture content, refractive index, density, TSS, and viscosity. The optimum level of EFS was 11.5 V/cm, which gave a higher yield (64.93%). OH, save consumed power and cost. The OH gave the highest scores of sensory characteristics compared to CH. Total sugars, monosaccharides, and ketone monosaccharides were detected in the date syrup, and the result was positive, while the quintuple sugars and multiple sugars were negative for all treatments. The OH reduced the cost by 85.78% compared with CH.

A review on Activated Carbon Prepared from Agricultural Waste using Conventional and Microwave Activation

In the recent years the research on the activated carbon preparation from agro-waste and byproducts have been increased due to their potency for agro-waste elimination. This paper presents a literature review on the synthesis of activated carbon from agro-waste using microwave irradiation method for heating. The applicable approach is highlighted, as well as the effects of activation conditions including carbonization temperature, retention period, and impregnation ratio. The review reveals that the agricultural wastes heated using a chemical process and microwave energy can produce activated carbon with a surface area that is significantly higher than that using the conventional heating method.

Microwave Facilitated Discovery of Substituted 1,2,4-triazaspiro[4.5] dec-2-en-3-amines: Biological and Computational Investigations

Background: Tuberculosis is an effectual infectious disease caused by the spread of tu-bercular bacteria within the lungs via droplets of coughs and sneezes. In 2021, 1.6 million people died due totuberculosis, which is the 13th leading killer disease and 2nd leading after COVID-19 infectious disease. Objective: Many drugs are available as antitubercular drug, but still, requires more efficacious drug molecules with lower toxicity, side effects and small-sized molecules. To fulfill said prospective, computational study such as molecular docking and ADMET studies guides towards an ideal drug molecule with small -sized, unique spiro structures. Methods: Conventional and microwave-initiated Reaction of cyclohexanone, hydrazine carbothio-amide, and 2-amino-4-methoxy-6-methyl-1,3,5-triazine affords compound 1, which is subjected to the Schiff base reaction with diverse aldehydes. All structures are defined using IR, 1H NMR, 13C NMR, and mass spectroscopy. The entire series is exposed to in vitro antibacterial and antitubercu-lar and in silico molecular docking and ADMET studies. Results: Compounds 2c and 2b have been established to be potential antibacterial agents, whereas compounds 2d, 2e, 2j, 2k and 2l are extremely effective against tubercular strains. Furthermore, molecular docking of related molecules is performed, and compounds 2d, 2e, 2j, 2k, and 2l have higher affinities toward antitubercular proteins. ADMET parameters such as water solubility, SA score, PCaco2 value, and TPSA values are satisfactory. Conclusion: The microwave method has been proven to be a greener method as compared to the con-ventional heating method. Comparative results of in vitro analysis are obtained with referenced anti-bacterial drugs and antitubercular drugs. In silico observations supports their in vitro assessments. Appraisal obtained from the ADMET study leads to the formation of ideal drug molecules.

Comparison between Transesterification Reaction with Microwave Heating and Conventional Heating for Biodiesel Production from Coconut Oil with Alkaline Catalyst

Biodiesel is a biofuel made from vegetable oil through an esterification-transesterification process. The process of making biodiesel is carried out by conventional heating methods and microwave heating. The reaction process was carried out according to the specified variables, with a concentration of 0.1% of the volume of methanol and a variable microwave power of 135, 225 and 315 watts with time variations of 5, 3 and 1 minute, as well as conventional heating at 60°C for 1 hour. The best result is the one using microwave heating with a power of 315 watts for 1 minute. The best biodiesel yield is 88.879%, with water content of 0.01%, an acid number of 0.56 Kg-KOH/g, a density of 0.892 g/mL and a viscosity of 2.617 cSt. The best result of biodiesel oil in comparison of is using the microwave heating method.

Battery-Operated and Self-Heating Solid-Phase Microextraction Device for Field Detection and Long-Term Preservation of Mercury in Soil.

The application of headspace solid-phase microextraction (HS-SPME) for mercury preservation and detection still has several shortcomings, including the use of high-temperature desorption chamber, the consumption of expensive reagent (NaBEt4 or NaBPr4), and analyte loss during sample storage. Herein, a self-heating HS-SPME device using a gold-coated tungsten (Au@W) fiber was developed for the field detection of mercury in soil by miniature point discharge optical emission spectrometry (μPD-OES). Hg2+ was reduced to Hg0 with NaBH4 solution and then preconcentrated with the Au@W fiber. The adsorbed Hg0 could be rapidly desorbed by directly heating the fiber with a mini lithium battery and subsequently detected by μPD-OES. A limit of detection (LOD) of 0.008 mg kg-1 was obtained with a relative standard deviation (RSD) of 2.4%. The accuracy of the self-heating HS-SPME was evaluated by analyzing a soil certified reference material (CRM) and nine soil samples with satisfactory recoveries (86-111%). Compared to the conventional external heating method, the proposed method reduces desorption time and power consumption from 80 s and 60 W to 20 s and 2.5 W, respectively. Moreover, the self-heating device enables the μPD-OES system to remove the high-temperature desorption chamber, making it more compact and suitable for field analytical chemistry. Interestingly, the Au@W SPME fiber can be also used for the long-term preservation of mercury with a sample loss rate <5% after 30 days of storage at room temperature.

Process parameters of microwave heating-assisted vacuum evaporation of tomato juice: quality, energy consumption, exergy performance, and kinetic processing

Increasing heating performance and preservation of product quality are critical factors in the food industry. Although microwave-vacuum heating is applied in many food processes, there are many unanswered questions about its effects on sensitive foods. In this study, the tomato juice was concentrated in microwave-vacuum heating system and results compared with conventional and conventional-vacuum heating methods. The effect of pressure and microwave power was investigated on quality parameters, energy consumption, exergy performance, and processing kinetics of tomato juice concentration. The processing time in the microwave-vacuum method was 2.3 to 6.3-fold lower than conventional and conventional-vacuum methods. The exergy performance was obtained in the range of 7.16–13.29% for microwave-vacuum heating and 2.04–2.99% for conventional methods. Microwave vacuum heating could reduce energy consumption by 30–71%, compared with conventional-vacuum methods. The minimum decline in ascorbic acid and total phenol content of tomato juice concentrate was observed for microwave-vacuum evaporation. Microwave-vacuum heating was an excellent concentration technique that provided tomato paste with improved nutritional quality, increasing exergy efficiency, reducing processing time and energy consumption compared to conventional and conventional vacuum processes.

Leaching Kinetics of Y and Eu from Waste Phosphors under Microwave Irradiation

Waste fluorescent powder contains a large amount of rare earth elements, which have a high value for recovery and utilization. In order to achieve the rapid and efficient leaching of rare earth elements in these waste phosphors, microwave-assisted leaching of rare earth elements Y and Eu from the waste phosphor with hydrochloric acid was studied. The maximum leaching rates of Y (99.84%) and Eu (89.82%) were obtained at 600 W microwave power, 60 min microwave radiation time at 60 °C. The leaching kinetics showed that the microwave leaching process of Y and Eu conforms to the chemical reaction control model, and the apparent activation energy is 25.30 kJ/mol and 24.78 kJ/mol. Compared with the conventional heating method, the microwave leaching process can obviously reduce the reaction activation energy, shorten the reaction time, and achieve the rapid and efficient leaching of rare earth elements in the waste phosphors.

Experimental and numerical investigation of fast preheating of lithium ion pouch cell via low-power inductive heating in cold climate

The fast preheating of lithium ion batteries (LIBs) is a challenge hindering its wide application in cold climate. This study proposes a new preheating method that employs an inductive heating operation. The performance of inductive heating on LIB is evaluated and compared with conventional heating methods using metal resistance film (MRF) and positive temperature coefficient (PTC) elements. Subsequently, an inductive heating numerical model is established to investigate the influence of critical factors, including current frequency and battery thickness, on the inductive heating performance. Results show that conventional MRF and PTC heating cannot provide safe fast preheating of LIBs owing to significant temperature difference inside battery. In comparison, inductive heating offers a better battery preheating performance with fast temperature increment, uniform temperature distribution and high efficiency. The battery utilizing sandwich inductive heating achieves a temperature increase rate up to 71.4 °C/min, an insignificant temperature deviation less than 6 °C, and a heating efficiency of 79.2% in the experimental test. The higher temperature uniformity of inductive heating is attributed to the fact that heat is generated within the battery electrode layers and that the contact thermal resistance induced by battery case can be eliminated. Moreover, the inductive heating performance is highly related with current frequency and battery thickness. The inductive heating of LIB is more suitable for operations at low frequencies, such as 10 kHz, as the skin effect of inductive heating can be decreased, and the temperature uniformity is increased. The battery thickness less than 4 mm is recommended as the maximum temperature deviation is less than 2 °C. This paper provides a preliminary investigation into the feasibility of LIB inductive preheating technology and offers new insights into the thermal management design of LIB application in cold climates.

Synthesis of thermoresponsive PNIPAm nanogel adsorbent by microwave-assisted polymerization for wastewater treatment application

This research demonstrated the fast synthesis technique using microwave-assisted polymerization for the preparation of thermoresponsive poly(N-isopropylacrylamide) (PNIPAm) nanogel which was to be used for paraquat pesticide adsorption. PNIPAm nanogel was synthesized by free-radical polymerization in an aqueous solution using water-soluble ammonium peroxodisulfate (APS) and N,Ń-methylenebisacrylamide (BIS) as initiators and cross-linker, respectively. Microwave irradiation was used as an alternative heating technique and its efficiency was compared to that of the conventional heating method. The results showed that reaction time could be greatly shortened from several hours to only 20 min with the yield of PNIPAm nanogel of approximately 65 % using microwave heating method. The FTIR analysis confirmed that microwave irradiation did not alter the chemical structure of PNIPAm nanogel. The cross-linker concentrations and the sequence of cross-linker addition affected the hydrodynamic diameter of PNIPAm nanogel. The hydrodynamic diameter of swollen PNIPAm nanogels at 25 °C decreased as increasing the cross-linker concentrations and then further decreased when the cross-linker was added after 10 min of the irradiation time. Besides, all PNIPAm nanogel showed well thermoresponsive reversibility over 5 cycles, across the volume phase transition temperature (VPTT) at around 32 °C. The adsorption and release mechanisms of the paraquat took advantage of the phase transition change (swelling-collapse) in response to temperature stimuli, respectively. The PNIPAm nanogel synthesized from the microwave heating method had a profound effect on paraquat adsorption, having 60 – 70 % adsorption with a paraquat release of around 35 – 45 %. These results demonstrated that PNIPAm nanogels could be used as an alternative adsorbent material for industrial wastewater treatment.