Structural design and experimental research of microwave radiation heater for asphalt pavements

In order to improve the efficiency of heating and the uniformity of temperature distribution in recycling asphalt mixtures, a pyramidal radiation heater is designed. The principles of designing horn surface size and antenna length are established according to the law of energy conservation and microwave antenna radiation theory. Modeling and simulation are carried out using IE3D software. The simulation results demonstrate that, with a fixed horn surface size, the shortened electric antenna length is the main factor leading to the improved heating uniformity. On the other hand, with a fixed antenna length and diminished surface size, the standing wave ratio decreases with the improved radiation efficiency. Furthermore, the efficiency of radiation drops with increased distance between the horn surface and the asphalt pavement. Microwave heating experiments are carried out using this type of heater. The temperature distribution of asphalt samples is obtained by the grid temperature measurement method, and Matlab simulation is performed. The experimental results are in good agreement with the simulation.

Effect of Low Level Subchronic Microwave Radiation on Rat Brain

Objective The present study was designed to investigate the effects of subchronic low level microwave radiation （MWR） on cognitive function, heat shock protein 70 （HSP70） level and DNA damage in brain of Fischer rats. Methods Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies： 900, 2800, and 2450 MHz. Animals were divided into 4 groups： Group I： Sham exposed, Group I1： animals exposed to microwave radiation at 900 MHz and specific absorption rate （SAR） 5.953 x 10-4 W/kg, Group II1： animals exposed to 1800 MHz at SAR 5.835 x 20-4 W/kg and Group IV： animals exposed to 2450 MHz at SAR 6.672 x 10-4 W/kg. All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues. HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay. Results Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function, increase in HSP70 level and DNA damage in brain. Conclusion The results of the present study suggest that low level microwave exposure at frequencies 900, 2800, and 2450 MHz may lead to hazardous effects on brain.

Application of Microwave Radiation to Extractive Metallurgy

In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.

Two-step method to extract seismic microwave radiation anomaly:Case study of M_s8.0 Wenchuan earthquake

The satellite remote sensing has become a promising technique for detecting earthquake and fault activities. But it is still very difficult to exactly extract the earthquake anomaly from the complicated remote sensing information. This paper presented a two-step method to extract the seismic microwave radiation anomaly related with earthquake, which could eliminate the stable influence of geography, terrain, coversphere and seasons, as well as the random influence of weather. Furthermore the two-step method was applied to analyze the anomaly of Wenchuan earthquake based on the data of AMSR-E. Microwave radiation anomalies were effectively detected related to the main shock and aftershocks. The extracted microwave radiation variation showed general features of three-stage： the positive radiation anomaly appeared around the epicenter in the first stage, quiet variation in the second stage, and abnormal area gradually moved to the epicenter in the third stage. After the main shock the microwave radiation anomalies distributed along the Longmenshan faults, and the epicenters of aftershocks were coincident with the anomaly area in space.

Inhibition of Micro RNA 219 Expression Protects Synaptic Plasticity via Activating NMDAR1, Ca MKIIγ,and p-CREB after Microwave Radiation

In recent decades,the potential health hazards of microwave exposure have been attracting increasing attention.Our previous studies have demonstrated that microwave exposure impaired learning and memory in experimental animal models[1,2].

Establishment of injury models in studies of biological effects induced by microwave radiation

Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.

Optimal Microwave Radiation Field Parameters for Mercury Ion Microwave Frequency Standards

We propose a method to determine the optimal power of the microwave resonance transition that simultaneously improves the signal-to-noise ratio and reduces line width based on saturation broadening theory and experiment. Saturation broadening spectra of the ground state hyperfine transition of trapped 199Hg＋ ions are measured and analyzed. The value of the optimal microwave power is obtained by using the proposed method and is verified. Rabi oscillations decay spectra of trapped 199Hg＋ ions are observed and the optimal microwave irradiation time for the maximum transition signal intensity is determined. This work will help to improve the short-term frequency stability of the mercury ion microwave frequency standard.

Effects of microwave radiation on brain energy metabolism and related mechanisms

With the rapid development of electronic technologies, anxiety regarding the potential health hazards induced by microwave radiation(MW) has been growing in recent years. The brain is one of the most sensitive target organs for microwave radiation, where mitochondrial injury occurs earlier and more severely than in other organs. Energy metabolism disorders do play an important role during the process of microwave radiation-induced brain damage. In this paper, we will review the biological effects of microwave radiation, the features of brain energy supply and consumption and the effects of microwave radiation on mitochondrial energy metabolism and potential related mechanisms.

Effects of microwave radiation on dynamic compressive properties of basalt

The dynamic mechanical properties of basalt affected by microwave were investigated by performing dynamic compressive tests using the SHPB system.Meanwhile,the thermal damage of the treated basalt was characterized by ultrasonic non-destructive testing and nuclear magnetic resonance technology.The results show that with the increase of microwave power and exposure time,the P-wave velocity,dynamic compressive strength and elastic modulus decrease continuously,and the dynamic failure mode tends to be a more complex fracturing.The increase in microwave power and exposure time can enhance the temperature difference and transfer coefficient among minerals,hence intensifying the rock damage induced by thermal shock.

2-Steps Preparation Activated Carbon from Solidago Canadensis:Carbonized by Electrial heating and Activated by Microwave Radiation

The activated carbon(AC)was prepared from Solidago Canadensis(SC),an alien invasive plant.The plant was firstly carbonized under nitrogen at 400 ℃ for 90 min in an electrical furnace,and then the carbonized product was activated with KOH through microwave radiation.Effects of KOH/C ratio,microwave power,microwave radiation time on the adsorption capacities and yield of AC were evaluated.It indicated that the optimum conditions were KOH/C ratio 2 g/g,microwave power 700 W,and microwave radiation time 6 min.The carbonation process of SC was analyzed by thermogravimetry(TG).The pore structural parameters and surface functional groups of the AC were characterized by nitrogen adsorption-desorption and Fourier Transformed Infrared Spectroscopy(FTIR),respectively.The activation yield,the surface area,the average pore size,and the average micropore size of AC prepared from optimum conditions were 53.75%,1 888 m2/g,0.567 nm,and 0.488 nm,respectively.The adsorption amounts of AC were 302.4 mg/g for methylene blue and 1 470.27 mg/g for iodine.

Kinetics of Oxidative Dearsenication of Niccolite Ore with Microwave Radiation

The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)^(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.

The combined effect of optical laser and microwave radiations on a metal surface

In this paper, it is shown that the laser radiation intensity required for complete ionization of vapors produced on an irradiated metal surface can be reduced by more than an order of magnitude through using pulsed laser radiation in combination with microwave radiation.

Nanoparticles assisted microwave radiation:Fluid-rock interactions in oil reservoirs

Recently,many researchers have focused on the usage of electromagnetic waves in oil production and well stimulation,but so far the effect of these waves on the fluid and rock interaction and its simultaneous effect with nanoparticles have not been investigated.Fluid-rock interaction is one of the most important factors affecting fluid distribution in the reservoirs.In this study,the oil reservoir rock wettability alteration under electromagnetic heating and the presence of nanoparticles has been investigated.Three nanoparticles of TiO_2,Fe_(3)O_(4),and TiO_2/Fe_(3)O_(4)have been utilized.TiO_2 nanoparticles are commercially available,and the other mentioned nanoparticles are synthesized via a co-precipitation method.Citric acid has been used to modify surfaces of nanoparticles and stabilize them in water as the base fluid.Also,the adsorption of the nanoparticles on the rock surface has been determined.In the next step,the amount of oil outflow from the rock has been measured and reported as the external fluid imbibition.In this process,the nanoparticle performance in wettability alteration was investigated using pH and inductively coupled plasma(ICP)analyses.To better understand the governing mechanisms,oil viscosity was measured by mixing the oil with nanoparticles and put under irradiation.The results reveal that the microwave has a great ability to reduce oil contact angle with carbonate rock.In the presence of0.2 wt%Fe_(3)O_(4)nanoparticles,the contact angle was reduced from 155°to 19°after 28 min of irradiation,indicating strong rock hydrophilicity.Furthermore,microwave irradiation on Fe_(3)O_(4)nanofluid extracts75%of the oil from the rock.With microwave radiation,the pH of the nanofluid increases and hence,more nanoparticles are adsorbed on the rock which subsequently causes more rock dissolution.The viscosity change results prove that there is an optimal irradiation time of 5 min in which oil viscosity reduces from 481 cP to 410 cP and then increases to 827 cP.Moreover,the application of further nanoparticles diminishes the oil viscosity at optimum irradiation time in which Fe_(3)O_(4)has the most oil viscosity reduction,representing 481 cP to 200 cP at 50%microwave power level.

Influence of Microwave Radiation on Properties and Structure of Fe_2O_3/SO_4^(2-) Solid Superacid Catalyst

The microwave radiation method was introduced to prepare the Fe_2O_3/SO solid superacid.Its structure and properties were investigated by means of X-ray diffraction and infrared spectrum analyses as well as measurement of magnetic susceptibility and rate of esterification. The structure of the superacids prepared in microwave field can be crystalline or non-crystalline, the latter has not been reported yet in literatures. Comparing with the traditional superacid, the non-crystalline Fe2O3/SO superacid prepared in microwave field has the highest magnetic susceptibility and catalytic activity. The di-coordination of Fe2O3 and SO and the S=O bi-bond were reinforced by microwave radiation, which is favorable for increasing the acid intensity of the Fe2O3/SO catalyst

Effect of Microwave Radiation on Dielectric Behavior of Two Vegetable Oils

The effect of microwave （MW） heating on the dielectric properties and oxidation processes of virgin olive oil and refined sunflower oil were determined by dielectric and UV- spectroscopy. Samples were heated in the microwave oven （850 W, 2.450 MHz） for 0 to 14 minutes. The results show degradation of dielectric characteristics, conductivity and oxidative stability of investigated oils, increasing with the exposure time. UV spectrum shows only one defined peak at 206 nm for olive oil confirming the dominant presence of monounsaturated fats and four peaks for sunflower oil （203 nm, 230 nm, 269 nm and 278 nm） dependent on polyunsaturated acid fats contents. Increasing of absorbance at all peak wave lengths indicates production of lipid oxidation, due to formation of conjugated monoenes and dienes and in small amounts due to trienes and secondary products like ketoaldehydes. Dielectric constant for olive oil is stable and almost unchangeable with MW radiation while sunflower oil＇s c＇ oscillates around the origin value in greater rate. Dielectric loss e＂ decreases with increasing time of MW radiation and its maximum shifts towards higher frequencies for sunflower oil indicating shortening of the relaxation times, while for olive oil it is unchanged. Cole-Cole analysis show the presence of only one relaxation process in the oils. Conductivity of oils is increasing in similar way with increasing frequency following the Jonscher＇s power law and is not changed with MW exposure time. Olive oil has conductivity higher for four orders of magnitude than sunflower oil, which is connected to the high content of monounsaturated fats. The differences between sunflower and olive oil characteristics are discussed.

HYDROTHERMAL SYNTHESIS OF ZEOLITE NaA BY MICROWAVE RADIATION

In this paper,we report a novel application of microwave radiation for the synthesis of zeolite NaA in a fraction of the time required for conventional synthetic method under very mild condition.The pure product was obtained under the condition of microwave radiation in 10-20 minutes.

Low-intensity Microwave Radiation of Natural Substances for Physiotherapy

The mechanisms of influence of physiotherapy procedures in ozokeriteparaffin therapy are considered in this paper.It is shown that microwave electromagnetic radiation formed by heated ozokerite-paraffin mixture is an important component of physiotherapy procedures.Using the experimental setup developed by the authors,the radiative abilities of ozokerite,paraffin and their mixtures in the microwave range were investigated.It was found that in the process of cooling the ozokerite-paraffin mixture,during the procedure,negative microwave fluxes occur,affecting the inflammatory processes in the patient’s body.The dependences of the microwave radiation level on the composition of the ozokerite-paraffin mixture are investigated.The results of experimental studies allowed us to evaluate the interaction of electromagnetic radiation of ozokerite-paraffin mixtures with human own electromagnetic radiation and to approach the choice of modes of therapeutic interaction more carefully.

SYNTHESIS OF MPt/C (M=La, Nd) CATALYSTS BY MICROWAVE RADIATION

In this paper, MPt/C (M= La, Nd) catalysts of PEMFC were synthesized by microwave radiation process. The crystallinity and structure of catalysts were respectively analyzed by XRD and nitrogen adsorption tests. The activity of catalysts was investigated by electrochemistry experiment. The results showed that: 1) compared with Pt/C catalyst prepared by typical impregnation-reduction process, the size of MPt/C catalyst particle decreased and the available crystal for O2 reduction increased; 2) the MPt/C catalysts had relatively high BET surface areas; and 3)these crystal transformations of the MPt/C catalyst brought high the electrocatalytic activity, and as a result, improved the power of PEMFC.

Synthesis and Investigation of the Activity of Cu-Cr-Co/Al2O3/Al-Catalysts in the Microwave Radiation-Stimulated Reaction Joint Deep Oxidation of Hydrocarbons and Carbon Monoxide

This article shows main principles and presents ideas described in the scientific and technical literature, on the mechanism of interaction of microwave radiation with a solid phase materials, which were used as a basis of creation of new perspective, energy efficient and environmentally safe technologies of preparation of heterogeneous catalysts for the reactions which were carried out under the influence of electro-magnetic radiation of microwave radiation. Author’s research results confirm possibilities of practical use of proposed method of hydrothermal oxidation of industrial low-dispersing of aluminum powders with presence of bulk phase of Al(ОН)3·nH2O, with further thermal treatment in microwave field for acquisition of armored А1/А12О33 compositions, which effectively consume energy of microwave radiation. Due to the textured characteristics and thermo-transforming ability, synthesized components can be used as potential universal bearings of catalysts for reactions stimulated by electromagnetic radiation of (2.45 GHz) microwave frequency.