Microwave Oven Method Research Articles

Impacts of pH on photocatalytic efficiency, the control of energy and morphological properties of CuO nanoparticles for industrial wastewater treatment applications

Copper oxide nanoparticles were synthesised using a microwave oven method at different pH conditions (2, 5, 9, 12) in this study. FTIR, PL, FE-SEM, EDAX, XRD, TEM, XPS, and photocatalytic activity were used to investigate the prepared materials. The standard monoclinic structure of the CuO nanoparticle is seen by XRD. The FE-SEM image depicts an agglomerated spherical granular shape. A PL spectrum of copper oxide nanoparticles reveals three peaks at 362 nm, 528 nm, and 596 nm. The existence of CuO nanoparticles in the molecular structure was confirmed by FTIR. HRTEM images indicate spherical morphology at 100 nm, 50 nm, and 20 nm. The SAED diagram's diffraction rings matched nicely with the XRD diagram's peaks. The EDAX spectra confirm the presence of copper and oxygen in abundance in these nanoparticles. During a malachite green dye treatment, the highest pH concentration was 98.33 % higher photocatalytic activity than the other samples. According to the XPS study, the two satellite peaks at 939 eV to 946 eV and 959 eV to 965 eV show the formation of CuO with the oxidation state Cu (+2). As part of the application to meet the needs of the company, the samples were tested for the photocatalytic decomposition of malachite green industrial dye under the irradiation of a visible light source, and the samples demonstrated an excellent result in the waste water decomposition of industrial dye in a very short period of time.the band gap energy values were found to be 1.71, 1.70, 1.69 and 1.68 eV.

Optimize the Properties of Carbon Nanotubes Synthesized using a Microwave Oven

In this paper, carbon nanotubes (CNT) are synthesized using the microwave oven method, which offers several advantages, including a simple, quick, inexpensive, and solvent-free growing method. To produce CNT, a mixture of graphite and ferrocene catalysts had to be flattened inside a microwave oven for five seconds at room temperature. CNT was produced using various ratios of graphite and ferrocene, and analyses indicated that a 70:30 graphite/ferrocene ratio produced better nanocrystalline CNT. To optimize CNT properties, five processes of purification were used to dispose of impurities like metal particles and support material from the as-produced carbon nanotubes. Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) was used to characterize the CNTs both after and before purification. After acid treatment and centrifugation, the amount of amorphous carbon and iron particles significantly decreased. Additionally, following the purification process, the ID/IG decreased by 0.14 and the I2D/ID increased by 0.55 for the purified CNTs. Furthermore, the FTIR spectra of the untreated and functionalized CNTs confirm the presence of carboxyl groups on pure CNTs and -OH moieties in sorbed water.

Investıgation of Drying Methods of Tarhana Produced in Çankırı Region by Taguchi Method

In this study, the drying behaviour of tarhana consumed in Çankırı region was investigated with various drying methods and optimum drying conditions were determined using experimental Taguchi design method. Solar, conventional oven and microwave oven methods were used for drying purposes. Different temperatures and microwave powers were used in the ovens and tarhana was also dried under sun light. The effective drying parameters were examined concerning the tarhana in the thickness and varying drying period. The data obtained were subjected to variance analysis. Statistical significance was determined in terms of strength, temperature, thickness and time parameters. Conventional oven drying optimization was found to be more successful with the lower p value than 0.01. After drying, tarhana was analysed from humidity, ash, protein and colour values. The results were evaluated for the solar, oven or microwave dried samples.

Evaluation of energy consumption in drying African oil bean seeds using response surface methodology

This research was set out to evaluate the specific energy consumption (SEC) in drying African oil bean seed using convective hot air and microwave oven dryers. The process parameters investigated in thin-layer drying were temperature (40, 50, 60, 70 °C), microwave power (450, 720, 900 W), slice thickness (2, 3, 5 mm) and treatment (untreated (UT), brine pretreated (BT) and sucrose pretreated (ST)). Response surface methodology (RSM) was used to evaluate the effect of oven temperature, microwave power, slice thickness, and treatment on the SEC of African oil bean seed. The result revealed that the SEC for African oil bean seed ranged from 21.12 to 57.33 k Wh kg−1 and 90.76 to 261.23 k Wh kg−1 for microwave and oven drying, respectively. The study also found that the SEC decreases with increase in slice thickness in both microwave and oven dryer. The microwave oven method reduced SEC of African oil bean seed by 22% compared to convective hot air oven drying method. The optimum SEC was obtained at 4 mm material thickness, 53.57 °C hot air oven temperature and 814.32 W microwave power. Among the treatments, BT sample is comparatively the best treatment for AOB in order to save drying energy consumption.

Traditional puffed fish cracker ('kemplang Palembang') by microwave-oven method: Physical properties and microstructure evaluation

This research has investigated the physical properties (volume expansion, texture) and microstructure of 'kemplang Palembang', traditional fish puffed crackers from Indonesia which were puffed using the microwave-oven method. The microwave-oven method was designed by the factorial randomised block design (FRBD) which contains egg addition as factors (A1 – control; A2 – egg yolk; A3 – egg white and egg yolk) and moisture factors (B1 – 7.5 ± 1%; B2 – 13.5 ± 1%). The results revealed that the egg addition and moisture were significant (P < 0.05) to the volume expansion and texture. Meanwhile, the microstructure of kemplang Palembang was evidenced by 3D visual analysis using the scanning electron microscopy (SEM) technique. The microstructural analysis by SEM showed that the porosity caused a significant change in volume expansion and texture. The results suggest the feasibility of adding eggs and moisture 13.5 ± 1% (A1B2 treatment) for proper volume expansion (523%), texture [156.2 gram-force (gf)], and microstructure.

Effects of different freezing and thawing methods on the quality of giant red shrimp (Aristaeomorpha foliacea)

The aim of this study was to investigate the effects of different freezing and thawing methods on physical, chemical, and sensory characteristics of red shrimp (Aristaeomorpha foliacea). Shell-on and shell-off shrimps were subjected to three different freezing (blast freezing, still freezing and cryogenic freezing) and thawing (on air, in refrigerator and in microwave oven) methods and stored for 30 days at -18ºC. Quality control analyses were carried out in samples after thawing. The lowest total volatile nitrogen and trimethylamine contents, pH values and cooking losses were found in cryogenically frozen shrimp, compared with other freezing methods. However, cryogenic freezing caused colour fading and softening in texture. It was determined that microwave thawing conditions used in this study are not suitable for thawing of frozen shrimp as it negatively affects texture and colour and increases cooking loss. It was found that blast freezing, and thawing methods preserved the physical, chemical and sensory properties of shrimp better than other methods.Keywords: Aristaeomorpha foliacea; Freezing; Red shrimp; Shrimp quality

Effects of different freezing and thawing methods on the quality of giant red shrimp (Aristaeomorpha foliacea)

The aim of this study was to investigate the effects of different freezing and thawing methods on physical, chemical, and sensory characteristics of red shrimp (Aristaeomorpha foliacea). Shell-on and shell-off shrimps were subjected to three different freezing (blast freezing, still freezing and cryogenic freezing) and thawing (on air, in refrigerator and in microwave oven) methods and stored for 30 days at -18ºC. Quality control analyses were carried out in samples after thawing. The lowest total volatile nitrogen and trimethylamine contents, pH values and cooking losses were found in cryogenically frozen shrimp, compared with other freezing methods. However, cryogenic freezing caused colour fading and softening in texture. It was determined that microwave thawing conditions used in this study are not suitable for thawing of frozen shrimp as it negatively affects texture and colour and increases cooking loss. It was found that blast freezing, and thawing methods preserved the physical, chemical and sensory properties of shrimp better than other methods.Keywords: Aristaeomorpha foliacea; Freezing; Red shrimp; Shrimp quality

Analysis of the ZnO/Cu2O and CdSe/Cu2O Thin Film Hetero-structure Electrode for Photo Electro chemical Solar Cell Applications

This paper proposes an economical route to the production of CdSe/Cu2O and ZnO/Cu2Obased on commercial ZnO, CdSe corpuscle. The deposition of CdSe thin films was prepared by partial thermal oxidation method, Powder Vaporization method, and microwave oven method on the cleaned Cu2O substrate at room temperature. The solar cell fabrication process is greatly simplified by this method and opens a door in the direction of inexpensive techniques based on saleable available materials. The results show that the solar cell based on the mixture of CdSe/Cu2O has electron transportability, better light absorption, and high power conversion efficiency (PCE) of 0.7 was obtained. These materials have been characterized using FTIR, at which numerous peaks are present in the sample, and were assessed in detail. Multiple current-voltage characteristic curves were plotted, an open-circuit voltage VOC, a short circuit current Isc, and the maximum power points Pmax were also noted. This work throws off more light in enhancing the photo response of the electrode in both solar H2generation and photo electro chemical solar cell

GROUND TRUTH SOIL MOISTURE ESTIMATION ALONG WITH MINIMAL DRIZZLING TIME

The aim of this study was to determine the soil moisture along with minimal drizzling time using two methods using hot air convection oven (HA-CO) and microwave oven (MO) to find out the best method for estimation the soil moisture. The convection oven method was considered as the most accurate method to determine the soil moisture; hence, we utilized this method as source for assessing the results. The experiment was conducted in lab which was completely based on random 110 dry soil samples weight of approximately 100 gram from the bare land. In convection oven method we used 105 °C for 24 hours and in microwave oven method we used different thermal power (180, 360, 540, 720 and 900 watt) for different time duration. The result based on the RMSE between soil moisture retrieval from hot air convection oven method and soil moisture retrieval from microwave oven method. 720 watt takes 15 minutes to dry the soil while 900 watt takes 8 minutes; both are gives approximately same results as convection oven method, which takes 24 Hours. Therefore for retrieval of soil moisture we can utilize the microwave oven method at 900 watt power. The low RMSE for 900 watt is 0.51% shows that the microwave oven method is most convenient, time saving and safe method for retrieval of soil moisture.

GELENEKSEL YÖNTEM VE MİKRODALGA İLE KUŞKONMAZIN (ASPARAGUS OFFICINALIS L.) KURUTULMASININ MODEL TABANLI KARŞILAŞTIRILMASI

In this study, asparagus slices were dried with traditional oven and microwave oven methods. Model based approach was used to investigate the differences and similarities between two drying methods. Weibullian and linear equations were used as the primary and secondary models, respectively. Secondary model integrated into the primary model could successfully be used to describe the moisture ratio of asparagus in one-step procedure. Appropriate fits were obtained for both drying techniques, but microwave drying had slightly better fit than the conventional drying. Tailing was observed for the curves of traditional drying whereas sigmoidal curves were observed for microwave drying. The time parameter (δ) value of the lowest power of the microwave drying (100 W) was just one third of the δ value of the highest temperature of the traditional drying (90 °C) indicating that microwave drying was effective method in terms of time comparing to traditional drying.

Effect of copper substitution on structural, optical and humidity-sensing characteristics of cerium oxide nanoparticles

Cerium (pure) and copper-substituted cerium oxide nanoparticles were synthesized by microwave oven method. Powder X-ray diffraction showed that particle size was reduced with increases in copper content, termed the “particle size effect”. Scanning electron microscopy and transmission electron microscopy (TEM) images showed that particle formation was spherical. Miniature sizes of nanoparticles were in the range ~4–10 nm and were identified from typical TEM microstructures. Absorption peaks were reduced as result of copper content and binding energy was also reduced, which decreased the particle size. The particle size effect produced significant changes in humidity sensing, copper-substituted cerium oxide nanoparticles had better humidity-sensing behavior than pure cerium oxide. Reproducibility of the sensor produced notable sensing characteristics.

Effect of film constituents and different processing conditions on the properties of starch based thermoplastic films

The main aim of this study is to examine the different film preparation methods (Hot air oven method, Microwave oven method, and UV irradiation method) for development of Bio-thermoplastic films from agro waste polysaccharides. The rheological properties were also studied for different combinations of tamarind seed starch (T), okra mucilage polysaccharide (OK), Residual rice bran starch (R) and sugarcane bagasse cellulose (C). Increase in concentration of okra mucilage polysaccharide and sugarcane bagasse cellulose found to highly influence the rheological viscous properties of tamarind starch solution. Increase in concentration of okra mucilage (above 1.5%) in tamarind film matrix solution significantly increased the elongation properties of starch films. Increase in concentration of cellulose (above 1%) in tamarind film matrix solution significantly increased the tensile strength of starch films. The microwave oven method was found to be the quickest method (~10 to 20 min) for biopolymer film preparation. SEM and AFM analysis revealed that UV – irradiation method produces stable bio-thermoplastic films with low surface roughness and high barrier properties. The interaction of starch molecules with other natural polysaccharide produces stable thermoplastic biopolymer films, that can be developed under different processing conditions to eradicate environmental pollution caused by petrochemical plastics.

Physicochemical and Sensory Properties of Broiler Chicken Breast Meat Stored Frozen and Thawed Using Various Methods

The paper presents an analysis of the impact of freezing storage duration (1, 3, 5, and 7 months) and thawing methods, namely, in atmospheric air, water, and using microwave oven on the quality properties of broiler chicken breast meat. The physicochemical indicators of raw breast meat after thawing and after being subjected to heat treatment were evaluated. The sensory evaluation was also conducted. The findings indicate that the duration of storage has effects on the quality of meat stored frozen at −20°C. Unfavourable changes (p<0.05) were observed between the first and seventh months of freezing storage in respect of such areas as increased drip loss, increased thermal loss, colour changes, and reduced ash content in thawed breast meat as well as in those subjected to heat treatment. Unfavourable changes in the sensory properties, namely, diminished intensity of flavour and aroma, were also observed. The analysis revealed significant (p<0.05) impacts of thawing methods on the meat’s quality properties, depending on the duration of freezing storage. The application of microwave oven method of thawing meat enabled the retention of better physicochemical properties (reduction of drip and thermal losses and increased ash content) as well as sensory properties such as the desirability of the flavor and juiciness of meat stored for one-month period. A longer period of freezing storage (5 and 7 months) revealed higher degrees of colour saturation towards red (a∗) in raw breast meat as well as reduced brittleness of breast meat thawed using microwave oven method prior to and after the heat treatment in comparison to those thawed using atmospheric air and water. Practical Applications. The duration of freezing storage and thawing methods has impacts on the meat’s quality, including its processing value. The current study has its practical implications due to the immense consumption of broiler chicken meat, the high proportion of deep frozen meat products in commerce, and the acceptability and popularity of frozen stored meat in households. The current study enables one to ascertain how the physicochemical and sensory properties of broiler chicken breast meat change over the period of freezing storage (for 1, 3, 5, and 7 months) and which of the applied thawing methods (in atmospheric air, water, or microwave method) is most favourable for retaining meat’s best quality.

Synthesis and Characterization of Cobalt Oxide Nanoparticles

The present work reports the synthesis and characterization of cobalt oxide nanoparticles. Microwave oven method was used for synthesizing cobalt oxide nanoparticles. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, photoluminescence (PL) and scanning electron microscope (SEM). The prepared samples show poor crystalline nature so that the samples were calcined at 300 °C for 1 hr. The calcined samples were characterized for further changes in its morphology. XRD identifies the sample is in Co3O4 phase with face-centered cubic structure. Debye-Scherer formula was used to calculate the average crystallite size of the annealed sample and it was found to be 7 to 28 nm. In addition to crystallite size, specific surface area, dislocation density and microstrain are calculated using XRD. Williamson-Hall plot was used to calculate the size and strain. FT-IR spectrum shows two stretching bands at 660 and 550 cm−1 which confirm the functional group present in the cobalt oxide nanoparticles. In optical absorption studies, a blue shift in the energy band gap reveals the quantum confinement effect. Photoluminescence spectra shows emission peak in the visible region.

Methods and extractants to evaluate silicon availability for sugarcane

The correct evaluation of silicon (Si) availability in different soil types is critical in defining the amount of Si to be supplied to crops. This study was carried out to evaluate two methods and five chemical Si extractants in clayey, sandy-loam, and sandy soils cultivated with sugarcane (Saccharum spp. hybrids). Soluble Si was extracted using two extraction methods (conventional and microwave oven) and five Si extractants (CaCl2, deionized water, KCl, Na-acetate buffer (pH 4.0), and acetic acid). No single method and/or extractant adequately estimated the Si availability in the soils. Conventional extraction with KCl was no more effective than other methods in evaluating Si availability; however, it had less variation in estimating soluble Si between soils with different textural classes. In the clayey and sandy soils, the Na-acetate buffer (pH 4.0) and acetic acid were effective in evaluating the Si availability in the soil regardless of the extraction methods. The extraction with acetic acid using the microwave oven, however, overestimated the Si availability. In the sandy-loam soil, extraction with deionized water using the microwave oven method was more effective in estimating the Si availability in the soil than the other extraction methods.

Cost-effective single-step carbon nanotube synthesis using microwave oven

This paper reports the characterization of carbon nanotubes (CNTs) synthesised using a conventional microwave oven method, offering several advantages including fast, simple, low cost, and solvent free growth process. The procedure involves flattening of graphite/ferrocene mixture catalyst inside the microwave oven under ambient conditions for a very short duration of 5 s, which inhibits the loss factor of graphite and ferrocene. The effect of graphite/ferrocene mixture ratio for the synthesis of CNTs is investigated by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), Raman spectroscopy and UV–NIR–Vis measurements. The samples produced using the different ratios contain nanotubes with an average diameter in the range 44–79 nm. The highest yield of CNTs is attained with graphite/ferrocene mixture ratio of 70:30. The lowest ID/IG ratio intensity as identified by Raman spectroscopy for 70:30 ratio indicates the improved crystallinity of CNTs. Due to the capillary effect of CNTs, Fe nanoparticles are found to be encapsulated inside the tubes at different positions along the tube length. The obtained results showed that the smaller the diameter of graphite and ferrocene favors the synthesis of graphene oxide upon microwave radiation.

NOTA TÉCNICA: USO DO SOFTWARE INTECPERÍMETRO® NO MANEJO DA IRRIGAÇÃO DO FEIJOEIRO

Objetivou-se com o presente trabalho utilizar o software IntecPerímetro® na avaliação do manejo da irrigação na cultura do feijão. O software foi alimentado por dados de clima, cultura, solo e os referentes ao equipamento de irrigação. A avaliação do manejo da irrigação procedeu-se pela comparação entre os valores médios de lâmina aplicada e tempo de funcionamento do equipamento de irrigação praticados pelo irrigante e calculados por meio do uso do software IntecPerímetro® em todas as fases de desenvolvimento da cultura, por meio do teste “t” de Student ao nível de 5% de probabilidade. A lâmina média de irrigação proposta pelo software foi 28,3% menor que a praticada pelo irrigante. Os valores de umidades obtidas em campo pelo método do forno micro-ondas não diferiram estatisticamente da umidade referente à lâmina de irrigação executada pelo irrigante utilizando o software.

A facile synthesis and neuroprotective role of novel quinoxaline-2,3-bis hydrazones in ethidium bromide-induced demyelinated rats

There is a growing interest in the design and synthesis of the quinoxaline-2,3-dione derivatives and hydrazones due to their neuroprotective activity, anticancer, anti-inflammatory, analgesic, anticonvulsant, antiviral, antibacterial and antifungal activity, and hydrazone-based coupling methods are used in medical biotechnology to couple drugs and also to target antibodies. Different series of α-amino-3-hydroxy-5-methylisoxazole propionate receptor antagonists are described to be effective in the therapy of neurodegenerative disorders in the literature, one of which is based on the quinoxaline-2,3-dione structure, which has a high affinity and selectivity over receptors. Quinoxaline-2,3-bis hydrazone(s) were prepared by the nucleophilic addition reaction at the second and third position of quinoxaline-2,3-dione using different hydrazines (a–f) in conventional and microwave oven methods successfully with the good percentage of yields. The six synthesized compounds showed satisfactory analytical results. The oral administration of the synthesized drugs (20 mg/kg body weight) showed its curative and preventive effect against intracranial administration of ethidium bromide-induced demyelination in rats proved by the battery of behavioral and histological studies. The synthesized drugs are useful to counteract various demyelinating disorders which will be a great relief for our society. Further studies are needed on the molecular mechanisms of these compounds with neuroprotective activity.

Research on Measurement of Grass’s Moisture Content with Microwave Oven Method

In the process of working, storage, finished fodder acceptance and the preservation process of grass materials, the moisture content of forage is a very important indicator. The blast oven drying method has been generally adopted in the measurement of moisture content. The related experiment showed that the microwave oven method for grass moisture content measuring improved 200-400 times in the efficiency compared with blast oven drying method. The microwave oven method was accurate and easy operating. So, we can conclude that microwave oven method is a viable method for measuring the moisture content.

Relative efficiency of sterilization methods for the treatment of glassware part of artificial vagina to be used for bovine semen collection

Present investigation was conducted on Sahiwal, HF crosses and Murrah bulls maintained at A.B. Complex, NDRI, Karnal (India) to identify the relative efficiency of various sterilization methods for the treatment of artificial vagina (AV) to be used for bovine semen processing. The glassware part of AV was sterilized by hot air oven at 160°C for 60 min. and microwave oven for 3 min. A total of 72 ejaculates were taken from 3 collections each from 4 bulls of each breed/species subjected to 2 types of treatments, then total plate count (TPC) of all these combinations was carried out using plate count agar media. Standardization of the best sterilizing method was done by selecting the method whose total bacterial count on the media was the least and the best semen quality (mass activity, initial motility, non-eosinophilic percent and abnormalities) was obtained. The microwave oven method of sterilization of glassware part of artificial vagina was found superior over hot air oven method.