On the basis of the analysis of the hexagons inscribed and circumscribed of the Mises yield circle on the π- plane in Haigh Westergaard stress space, a new equation called equal area linear yield criterion or EA crit...On the basis of the analysis of the hexagons inscribed and circumscribed of the Mises yield circle on the π- plane in Haigh Westergaard stress space, a new equation called equal area linear yield criterion or EA criterion was proposed, and its plastic specific work rate was derived. Then, a generalized worked example of plate rolling was analyzed by the criterion and its corresponding plastic specific work rate. Finally, the precision of the solution was compared with measured roll separation force in plate finish rolling process. It indicates that the calculated results by EA criterion are slightly higher than the measured ones.展开更多
Based on the theory of substrate permeation through the cytoplasmic membrane,and considering the effect of initial concentration of substrate,a new kinetic model of phenol degradation process was proposed,Comparing wi...Based on the theory of substrate permeation through the cytoplasmic membrane,and considering the effect of initial concentration of substrate,a new kinetic model of phenol degradation process was proposed,Comparing with the widely used Haldane model,which is greatly dependent on the initial phenol concentration,our model can be used to simulate the phenol degradation process in a wide range of initial phenol concentration by using only one set of model parameters ,Therefore,this new kinetic model has much more potential applications to industrial design and operation.展开更多
A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaozhou Bay is described in this paper. Light intensity, temperature and nutrients (nitrate + ammonia, phospha...A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaozhou Bay is described in this paper. Light intensity, temperature and nutrients (nitrate + ammonia, phosphate) were considered as main factors controlling photosynthesis of phytoplankton and were introduced into the model by different function equations. The simulated variation of specific photosynthesis rate coincided with the measured data. Analysis of the effect of every factor on photosynthesis indicated that the variation of photosynthesis rate was controlled by all these three factors, while temperature showed good correlation with SPR as measurement showed. This diagnostic simulation yielded the values of some parameter relating with the photosynthesis in Jiaozhou Bay.展开更多
The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of ...The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of this work are to evaluate the knowledge and awareness about SAR among human body and mobile base station.The paper investigates the electromagnetic wave absorption inside a human body.The human body has been identified using dataset based on 2D object considering different electrical parameters.The SAR convinced inside the human body model exposed to a radiating base station antenna(BSA)has been considered for multiple numbers of carrier frequencies and input power of 20 W/carrier at GSM 900 band.The distance(R)of human body from BSA is varied in the range of 0.1 m to 5.0 m.For the number of carrier frequency equal to one and R=0.1 m,the concentrated value of whole-body average SAR obtained by FDTD technique is found to be 0.68 W/kg which decreases either with increase of R or decrease of number of carrier frequencies.Safety distance for general public is found to be 1.5 m for number of carrier frequencies equal to one.The performance accuracy of this analysis meets the high level condition by comparing with the relevant system development in recent time.展开更多
Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 y...Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 yield in R.sphaeroides.In this study,a precise regulation strategy based on dielectric spectroscopy(DS)was applied to further improve CoQ10 biosynthesis by R.sphaeroide.First,a quantitative response model among viable cells,cell morphology,and oxygen uptake rate(OUR)was established.DS could be used to detect viable R.sphaeroides cells,and the relationship among cell morphology,CoQ10 biosynthesis,and OUR was found to be significant.Based on this model,the online specific oxygen consumption rate(QO2)control strategy was successfully applied to the CoQ10 fermentation process.QO2 controlled at 0.07±0.01×10−7mmol/cell/h was most favorable for CoQ10 biosynthesis,resulting in a 28.3%increase in CoQ10 production.Based on the multi-parameters analysis and online QO2 control,a precise online nutrient feeding strategy was established using conductivity detected by DS.CoQ10 production was improved by 35%,reaching 3384 mg/L in 50 L bioreactors.This online control strategy would be effectively applied for improving industrial CoQ10 production,and the precise fermentation control strategy could also be applied to other fermentation process.展开更多
Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the...Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the design of electroencephalography electrodes in fully implanted BCI systems,this study investigates the penetration and absorption characteristics of microwave signals in human brain tissue at different frequencies.Electromagnetic simulations are used to analyze the power density distribution and specific absorption rate(SAR)of signals at various frequen-cies.The results indicate that lower-frequency signals offer advantages in terms of power density and attenuation coeffi-cients.However,SAR-normalized analysis,which considers both power density and electromagnetic radiation hazards,shows that higher-frequency signals perform better at superficial to intermediate depths.Specifically,at a depth of 2 mm beneath the cortex,the power density of a 6.5 GHz signal is 247.83%higher than that of a 0.4 GHz signal.At a depth of 5 mm,the power density of a 3.5 GHz signal exceeds that of a 0.4 GHz signal by 224.16%.The findings suggest that 6.5 GHz is optimal for electrodes at a depth of 2 mm,3.5 GHz for 5 mm,2.45 GHz for depths of 15-20 mm,and 1.8 GHz for 25 mm.展开更多
Objective] The aim was to explore the potential of Nitzschia capitel ata as excel ent baits and bioenergy, and the optimal light intensity and nitrogen-to-phos-phorus （N/P） ratio suitable for its growth were researc...Objective] The aim was to explore the potential of Nitzschia capitel ata as excel ent baits and bioenergy, and the optimal light intensity and nitrogen-to-phos-phorus （N/P） ratio suitable for its growth were researched as wel . [Method] With light intensity gradient set, Nitzschia capitel ata was cultured with the same nutrients at （25 ±1） ℃ and light cycle at 12 h/d to select optimal light intensity. Then, Nitzschia capitel ata was cultured with the same condition, and nitrogen-to-phospho-rus ratios at 5∶1, 6∶1, 7∶1 and 8∶1. [Result] With light intensity at 3 000 lx, specific growth rate and standing stock achieved the highest at 0.51 d-1 and 7.97×104 cel s/ml. The growth condition with nitrogen-to-phosphorus ratio at 6∶1 was the most suitable for Nitzschia capitel ata growth. [Conclusion] The optimal light intensity and nitrogen-to-phosphorus ratio were 3 000 lx and 6∶1, respectively, for Nitzschia capitel ata.展开更多
Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods...Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods: The finite element method (FEM) was used to calculate,electromagnetic field and SAR distribution. Two different structure applicators were simulated. Theone is simple coaxial antenna, which has been successfully used in clinic treating bone tumors inTangdu hospital of the Forth Military Medical University several years. It was formed by a coaxialcable peeled off the out copper at end. The other applicator was coaxial- slot antenna, which waswidely used in microwave hyperthermia. The applicator inserted into the cylindrical bone withdifferent depths, and worked at the frequency of 2 450 MHz. Results: The electric field and SARgenerated by the simple coaxial applicator were mainly concentrated out the tissues, and were notuniform in the tissues, while the coaxial- slot applicator well transmits the electric field and SARinto the tissues, and can easily treat different position by adjusting the slat position.Conclusion: The results calculated by EFM, were well accordant with the experimental and clinicalresulls, and will be important for improving the clinical effects of microwave hyperthermia.展开更多
Nitrifying biomass on ring-shaped carriers was modified to nitritating one in a relatively short period of time （37 days） by limiting the air supply, changing the aeration regime, shortening the hydraulic retention ...Nitrifying biomass on ring-shaped carriers was modified to nitritating one in a relatively short period of time （37 days） by limiting the air supply, changing the aeration regime, shortening the hydraulic retention time and increasing free ammonia （FA） concentration in the moving-bed biofilm reactor （MBBR）. The most efficient strategy for the development and maintenance of nitritating biofilm was found to be the inhibition of nitrifying activity by higher FA concentrations （up to 6.5 mg/L） in the process. Reject water from sludge treatment from the Tallinn Wastewater Treatment Plant was used as substrate in the MBBR. The performance of high-surfaced biocarriers taken from the nitritating activity MBBR was further studied in batch tests to investigate nitritation and nitrification kinetics with various FA concentrations and temperatures. The maximum nitrite accumulation ratio （96.6%） expressed as the percentage of NO 2 ？ -N/NOx ？ -N was achieved for FA concentration of 70 mg/L at 36°C. Under the same conditions the specific nitrite oxidation rate achieved was 30 times lower than the specific nitrite formation rate. It was demonstrated that in the biofilm system, inhibition by FA combined with the optimization of the main control parameters is a good strategy to achieve nitritating activity and suppress nitrification.展开更多
In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater...In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated. Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown. They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could be fully restored about 3 weeks after re-activation. Metabolic activity, however, dropped to 15 8 mg O_2/(g MLVSS·h), i.e. 74 % reduction after 2 months of storage. After restarting the reactor, it took 2 weeks that SOUR of up to 48 5 mg O_2 /(g MLVSS·h) was achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.展开更多
Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate （SGR） and chlorophyll fluores...Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate （SGR） and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50, and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence （F_v/F_m） were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO_4-P. The photosynthetic capacity of photosystem Ⅱ （PSⅡ） was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO_3-N concentrations were greater than 1.0 mmol/L and when PO4-P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera, these data contribute important information to ensure optimal results.展开更多
On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the...On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used,the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol type fermentation of the acidogenic phase is the optimal acid type fermentation for the two phase anaerobic process.展开更多
Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) an...Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).展开更多
Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga ...Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga Tetraselmis subcordiformis and the macroalga Ulva pertusa. Two new parameters, the maximum specific uptake rate ( V sp m) and the maximal growth efficiency ( β ), are introduced to achieve uniformity for the comparison of nutrient uptake and growth efficiency between microalgae and macroalgae. T. subcordiformis possesses 3 times lower half saturation uptake constant, 4 times higher maximal growth rate and 20 times higher maximum specific uptake rate than U. pertusa, while U. pertusa possesses 4 times higher maximal growth efficiency than T. subcordiformis.展开更多
The effect of salinity on the growth and muscle nutritional quality of theExopalaemon carinicauda was studied through testing the survival rate, specific growthrate, muscle nutrient composition, amino acid composition...The effect of salinity on the growth and muscle nutritional quality of theExopalaemon carinicauda was studied through testing the survival rate, specific growthrate, muscle nutrient composition, amino acid composition and content by the culturingin different salinities(0-30).The results showed that the survival rate of salinity (0-30)had no significant difference (P>0.05), and the specific growth rates at salinity 15 andsalinity 20 were significantly higher than others(P>0.05); the muscle moisture contentand the crude fat content significantly decreased(P<0.05), while the muscle crudeprotein content significantly increased with an increase in the environment salinity from0 to 30(P <0.05).The crude ash content with salinity increase had a slight increase; themuscle crude protein content (18.2) at salinity 15 was significantly higher than that atsalinity 0,5, or 10(P <0.05), but there was no significant difference between salinity 15and salinity 20(P>0.05). No significant difference was found in total amino acid contentor total essential amino acid content from salinity 0 to 30(P>0.05). Total delicious aminoacid content at salinity 15-30 was significantly higher than those at salinity 0-10(P<0.05), while there was no significant difference from salinity 15 to 30(P>0.05). Theresults suggest that the suitable salinity for muscle nutritive value ranges from 15 to 30,and the Exopalaemon carinicauda can potentially be cultured above the salinity 15.展开更多
Iron alloyed Ni3Al with composition of Ni-18. 8Ab10. 7Fe-0. 5Mn-0. 5Ti-0. 2B in atom percent （NAC alloy） showed attractive tribological properties under unlubrication condition at room temperature. The alloy was pre...Iron alloyed Ni3Al with composition of Ni-18. 8Ab10. 7Fe-0. 5Mn-0. 5Ti-0. 2B in atom percent （NAC alloy） showed attractive tribological properties under unlubrication condition at room temperature. The alloy was prepared by hot isostatic pressing （HIP） process. The wear properties were associated with its intrinsic deformation mechanism. Unfortunately, the single phase NAC-alloy worked inadequately with its counterpart disk, and also showed a poor machinability. In the present work, NAC-alloy matrix composite with 6 % （volume percent） MnS particle addi- tion was studied to improve its wear behaviors and performance on machining. Two metallurgical processes of HIP and vacuum casting were applied to produce the testing materials. Pin-on-disk （POD） measurements were carried out at room temperature. A commercial vermicular graphite cast iron was selected as a reference material. The counter- part disk was made of a grey cast iron as liner material in ship engines. The contact pressures of 2.83 MPa and 5.66 MPa were normally applied in the tests. The investigation indicated that MnS particle addition in the NAC-alloy composites functions as an effective solid lubricant, and improved wear properties and machinability of the materials. Obvi- ously, as-cast NAC-alloy with in-situ formed MnS-phase was working more effectively with the counterpart, compa- ring to the HIPed NAC-alloy composite with MnS particles. At the high contact pressure of 5.66 MPa, the specific wear rate of the as-cast NAC-alloy composite was high. The phenomenon of the negative effect is mostly due to the brittle second NiAl phase as evidenced in the microstructure analysis.展开更多
Microwave-induced thermoacoustic imaging(MI-TAI)remains one of the focus of attention among biomedical imaging modalities over the last decade.However,the transmission and dis-tribution of microwave inside bio-tissues...Microwave-induced thermoacoustic imaging(MI-TAI)remains one of the focus of attention among biomedical imaging modalities over the last decade.However,the transmission and dis-tribution of microwave inside bio-tissues are complicated,thus result in severe artifacts.In this study,to reveal the underlying mechanisms of artifacts,we deeply investigate the distribution of specific absorption rate(SAR)inside tissue-mimicking phantoms with varied morphological features using both mathematical simulations and corresponding experiments.Our simulated results,which are confirmed by the associated experimental results,show that the SAR distri-bution highly depends on the geometries of the imaging targets and the polarizing features of the microwave.In addition,we propose the potential mechanisms including Mie-scattering,Fabry-Perot-feature,small curvature effect to interpret the diffraction effect in different scenarios,which may provide basic guidance to predict and distinguish the artifacts for TAI in both fundamental and clinical studies.展开更多
The information extracted from monitoring of rotary blasthole drills helps to optimize the overall mining operation. Rock hardness, drillability, blastability and specific energy of drilling are examples of parameters...The information extracted from monitoring of rotary blasthole drills helps to optimize the overall mining operation. Rock hardness, drillability, blastability and specific energy of drilling are examples of parameters that have been estimated in the past using measurement while drilling techniques. In order to be able to properly utilize measurement while drilling techniques, it is important to properly collect, analyze and interpret extracted data. This paper deals with processing of measurement while drilling data such as rate of penetration, rotary speed, rotary torque and pulldown force collected from rotary blasthole drills.Different methods are discussed to calculate a true rate of penetration which is the most important monitored drill variable for use in rock mass characterization. Then specific energy of drilling is defined and calculated based on electrical and mechanical inputs and the results are compared. The results show that specific energy of drilling can be estimated using the drill's primary drive systems' electrical responses with good accuracy when compared to values based on mechanical inputs.展开更多
A heuristic stochastic solution of the Pennes equation is developed in this paper by applying the self-organizing, self-similar behaviour of living structures. The stochastic solution has a probability distribution th...A heuristic stochastic solution of the Pennes equation is developed in this paper by applying the self-organizing, self-similar behaviour of living structures. The stochastic solution has a probability distribution that fits well with the dynamic changes in the living objects concerned and eliminates the problem of the deterministic behaviour of the Pennes approach. The solution employs the Weibull two-parametric distribution which offers satisfactory delivery of the rate of temperature change by time. Applying the method to malignant tumours obtains certain benefits, increasing the efficacy of the distortion of the cancerous cells and avoiding doing harm to the healthy cells. Due to the robust heterogeneity of these living systems, we used thermal and bioelectromagnetic effects to distinguish the malignant defects, selecting them from the healthy cells. On a selective basis, we propose an optimal protocol using the provided energy optimally such that molecular changes destroy the malignant cells without a noticeable effect on their healthy counterparts.展开更多
A successful enhanced biological phosphorus removal （EBPR） was observed in both anaerobic- aerobic sequencing batch reactor （An-Ox SBR） to induce growth of phosphorus accumulating organism （PAO） and anaerobic-an...A successful enhanced biological phosphorus removal （EBPR） was observed in both anaerobic- aerobic sequencing batch reactor （An-Ox SBR） to induce growth of phosphorus accumulating organism （PAO） and anaerobic-anoxic （An-Ax） SBR to induce growth of denitrifying PAO （DPAO）. Although the EBPR performance of An-Ox SBR was higher by 11.3% than that of An-Ax SBR, specific phosphorus release rates in the An-Ax SBR （22.8 ± 3.5 mg P/（g VSS.hr）） and the An-Ox SBR （22.4 ± 4.8 mg P/（g VSS.hr）） were similar. Specific phosphorus uptake rates under anoxic and aerobic conditions were 26.3 ± 4.8 mg P/（g VSS.hr） （An-Ax SBR） and 25.6 ± 2.8 mg P/（g VSS.hr） （An-Ox SBR）, respectively, which were also similar. In addition, an analysis of relationship of poly-β-hydroxyalkanoates （PHA） synthesized under anaerobic conditions with phosphorous release （Preleased/PHAsynthesized） and of PHA utilized under anoxic and aerobic conditions with phosphorous uptake （Puptaked/PHAutilized） verified that biological activities of EBPR per unit biomass between DPAO and PAO were similar. An analysis of the specific denitrification rate of DPAO showed that NO3-N can be denitrified at a rate that does not substantially differ from that of an ordinary denitrifier without additional consumption of organic carbon when the PHA stored inside the cell under anaerobic conditions is sufficiently secured.展开更多
基金Item Sponsored by National Natural Science Foundation of China(50474015)RAL Self-Determination Science Foundation of China(RAL-SD-2008-2)
文摘On the basis of the analysis of the hexagons inscribed and circumscribed of the Mises yield circle on the π- plane in Haigh Westergaard stress space, a new equation called equal area linear yield criterion or EA criterion was proposed, and its plastic specific work rate was derived. Then, a generalized worked example of plate rolling was analyzed by the criterion and its corresponding plastic specific work rate. Finally, the precision of the solution was compared with measured roll separation force in plate finish rolling process. It indicates that the calculated results by EA criterion are slightly higher than the measured ones.
基金Supported by China Petroleum & Chemical Corporation (X599011).
文摘Based on the theory of substrate permeation through the cytoplasmic membrane,and considering the effect of initial concentration of substrate,a new kinetic model of phenol degradation process was proposed,Comparing with the widely used Haldane model,which is greatly dependent on the initial phenol concentration,our model can be used to simulate the phenol degradation process in a wide range of initial phenol concentration by using only one set of model parameters ,Therefore,this new kinetic model has much more potential applications to industrial design and operation.
文摘A simple diagnostic simulation of the annual cycling of the surface specific photosynthesis rate (SPR) in Jiaozhou Bay is described in this paper. Light intensity, temperature and nutrients (nitrate + ammonia, phosphate) were considered as main factors controlling photosynthesis of phytoplankton and were introduced into the model by different function equations. The simulated variation of specific photosynthesis rate coincided with the measured data. Analysis of the effect of every factor on photosynthesis indicated that the variation of photosynthesis rate was controlled by all these three factors, while temperature showed good correlation with SPR as measurement showed. This diagnostic simulation yielded the values of some parameter relating with the photosynthesis in Jiaozhou Bay.
基金This work is collaborative research with the Department of Electronics&Communication Engineering,Acharya Institute of Technology,Bengaluru,India.And also this work is a collaborative research between Yangon Technological University and University of Oulu in Finland based on the enhancement of Telecommunication Engineering Education in YTU.This work is fully supported by the government research funds of 2020-2021 academic year which is the grant no of GB/D(4)2020/4.
文摘The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of this work are to evaluate the knowledge and awareness about SAR among human body and mobile base station.The paper investigates the electromagnetic wave absorption inside a human body.The human body has been identified using dataset based on 2D object considering different electrical parameters.The SAR convinced inside the human body model exposed to a radiating base station antenna(BSA)has been considered for multiple numbers of carrier frequencies and input power of 20 W/carrier at GSM 900 band.The distance(R)of human body from BSA is varied in the range of 0.1 m to 5.0 m.For the number of carrier frequency equal to one and R=0.1 m,the concentrated value of whole-body average SAR obtained by FDTD technique is found to be 0.68 W/kg which decreases either with increase of R or decrease of number of carrier frequencies.Safety distance for general public is found to be 1.5 m for number of carrier frequencies equal to one.The performance accuracy of this analysis meets the high level condition by comparing with the relevant system development in recent time.
基金supported by the financial support of research projects from the National Key R&D Program of China(No.2021YFC2101000)Shanghai Scientific and Technological Innovation Action Plans-Scientific Instrument Development,China(grant No.21142201300,22142201000)+1 种基金National Natural Science Foundation of China(No.32071471 and No.22078295)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_2866).
文摘Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 yield in R.sphaeroides.In this study,a precise regulation strategy based on dielectric spectroscopy(DS)was applied to further improve CoQ10 biosynthesis by R.sphaeroide.First,a quantitative response model among viable cells,cell morphology,and oxygen uptake rate(OUR)was established.DS could be used to detect viable R.sphaeroides cells,and the relationship among cell morphology,CoQ10 biosynthesis,and OUR was found to be significant.Based on this model,the online specific oxygen consumption rate(QO2)control strategy was successfully applied to the CoQ10 fermentation process.QO2 controlled at 0.07±0.01×10−7mmol/cell/h was most favorable for CoQ10 biosynthesis,resulting in a 28.3%increase in CoQ10 production.Based on the multi-parameters analysis and online QO2 control,a precise online nutrient feeding strategy was established using conductivity detected by DS.CoQ10 production was improved by 35%,reaching 3384 mg/L in 50 L bioreactors.This online control strategy would be effectively applied for improving industrial CoQ10 production,and the precise fermentation control strategy could also be applied to other fermentation process.
基金The Open Project of State Key Laboratory of Smart Grid Protection and Operation Control in 2022(No.SGNR0000KJJS2302150).
文摘Fully implanted brain-computer interfaces(BCIs)are preferred as they eliminate signal degradation caused by interference and absorption in external tissues,a common issue in non-fully implanted systems.To optimize the design of electroencephalography electrodes in fully implanted BCI systems,this study investigates the penetration and absorption characteristics of microwave signals in human brain tissue at different frequencies.Electromagnetic simulations are used to analyze the power density distribution and specific absorption rate(SAR)of signals at various frequen-cies.The results indicate that lower-frequency signals offer advantages in terms of power density and attenuation coeffi-cients.However,SAR-normalized analysis,which considers both power density and electromagnetic radiation hazards,shows that higher-frequency signals perform better at superficial to intermediate depths.Specifically,at a depth of 2 mm beneath the cortex,the power density of a 6.5 GHz signal is 247.83%higher than that of a 0.4 GHz signal.At a depth of 5 mm,the power density of a 3.5 GHz signal exceeds that of a 0.4 GHz signal by 224.16%.The findings suggest that 6.5 GHz is optimal for electrodes at a depth of 2 mm,3.5 GHz for 5 mm,2.45 GHz for depths of 15-20 mm,and 1.8 GHz for 25 mm.
基金Supported by Guizhou Provincial Science&Technology Fund((2010)2067)~~
文摘Objective] The aim was to explore the potential of Nitzschia capitel ata as excel ent baits and bioenergy, and the optimal light intensity and nitrogen-to-phos-phorus （N/P） ratio suitable for its growth were researched as wel . [Method] With light intensity gradient set, Nitzschia capitel ata was cultured with the same nutrients at （25 ±1） ℃ and light cycle at 12 h/d to select optimal light intensity. Then, Nitzschia capitel ata was cultured with the same condition, and nitrogen-to-phospho-rus ratios at 5∶1, 6∶1, 7∶1 and 8∶1. [Result] With light intensity at 3 000 lx, specific growth rate and standing stock achieved the highest at 0.51 d-1 and 7.97×104 cel s/ml. The growth condition with nitrogen-to-phosphorus ratio at 6∶1 was the most suitable for Nitzschia capitel ata growth. [Conclusion] The optimal light intensity and nitrogen-to-phosphorus ratio were 3 000 lx and 6∶1, respectively, for Nitzschia capitel ata.
文摘Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods: The finite element method (FEM) was used to calculate,electromagnetic field and SAR distribution. Two different structure applicators were simulated. Theone is simple coaxial antenna, which has been successfully used in clinic treating bone tumors inTangdu hospital of the Forth Military Medical University several years. It was formed by a coaxialcable peeled off the out copper at end. The other applicator was coaxial- slot antenna, which waswidely used in microwave hyperthermia. The applicator inserted into the cylindrical bone withdifferent depths, and worked at the frequency of 2 450 MHz. Results: The electric field and SARgenerated by the simple coaxial applicator were mainly concentrated out the tissues, and were notuniform in the tissues, while the coaxial- slot applicator well transmits the electric field and SARinto the tissues, and can easily treat different position by adjusting the slat position.Conclusion: The results calculated by EFM, were well accordant with the experimental and clinicalresulls, and will be important for improving the clinical effects of microwave hyperthermia.
基金supported by the Estonian Environmental Investment Center Program "Treatment of Nitrogen- rich Wastewaters (SLOTI08262)"a target-financed project of the Estonian Ministry of Education and Research NoSF0180135s08, named "Processes in macro-and microheterogeneous and nanoscale systems and related technological applications"
文摘Nitrifying biomass on ring-shaped carriers was modified to nitritating one in a relatively short period of time （37 days） by limiting the air supply, changing the aeration regime, shortening the hydraulic retention time and increasing free ammonia （FA） concentration in the moving-bed biofilm reactor （MBBR）. The most efficient strategy for the development and maintenance of nitritating biofilm was found to be the inhibition of nitrifying activity by higher FA concentrations （up to 6.5 mg/L） in the process. Reject water from sludge treatment from the Tallinn Wastewater Treatment Plant was used as substrate in the MBBR. The performance of high-surfaced biocarriers taken from the nitritating activity MBBR was further studied in batch tests to investigate nitritation and nitrification kinetics with various FA concentrations and temperatures. The maximum nitrite accumulation ratio （96.6%） expressed as the percentage of NO 2 ？ -N/NOx ？ -N was achieved for FA concentration of 70 mg/L at 36°C. Under the same conditions the specific nitrite oxidation rate achieved was 30 times lower than the specific nitrite formation rate. It was demonstrated that in the biofilm system, inhibition by FA combined with the optimization of the main control parameters is a good strategy to achieve nitritating activity and suppress nitrification.
文摘In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated. Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown. They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could be fully restored about 3 weeks after re-activation. Metabolic activity, however, dropped to 15 8 mg O_2/(g MLVSS·h), i.e. 74 % reduction after 2 months of storage. After restarting the reactor, it took 2 weeks that SOUR of up to 48 5 mg O_2 /(g MLVSS·h) was achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.
基金Supported by the Technology Program of Basic Research of Qingdao(No.12-1-4-8-(2)-jch)
文摘Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate （SGR） and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50, and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence （F_v/F_m） were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO_4-P. The photosynthetic capacity of photosystem Ⅱ （PSⅡ） was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO_3-N concentrations were greater than 1.0 mmol/L and when PO4-P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera, these data contribute important information to ensure optimal results.
文摘On the basis of continuous tests and batch tests, conversion regular patterns of acetate, propionate and butyrate in activated sludge at different heights of the UASB reactor were conducted. Results indicated that the conversion capacity of the microbe is decided by the substrate characteristic when sole VFA is used as the only substrate. But when mixed substrates are used,the conversion regulations would have changed accordingly. Relationships of different substrates vary according to their locations. In the whole reactor, propionate's conversion is restrained by acetate and butyrate of high concentration. On the top and at the bottom of the reactor, conversion of acetate, but butyrate, is restrained by propionate. And in the midst, acetate's conversion is accelerated by propionate while that of butyrate is restrained. It is proved, based on the analysis of specific conversion rate, that the space distribution of the microbe is the main factor that affects substrates' conversion. The ethanol type fermentation of the acidogenic phase is the optimal acid type fermentation for the two phase anaerobic process.
基金Project(2014CB643401) supported by the National Basic Research Program of ChinaProject(51674294) supported by the National Natural Science Foundation of ChinaProject(2016TP1007) supported by the Hunan Provincial Science and Technology Plan,China
文摘Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).
基金supported by the Project under Major State Basic Research of China(G1999012011).
文摘Short term uptake experiments and long term semicontinuous culture experiments were performed under the condition of phosphorus (P) limitation to estimate and compare the P uptake and growth kinetics of the microalga Tetraselmis subcordiformis and the macroalga Ulva pertusa. Two new parameters, the maximum specific uptake rate ( V sp m) and the maximal growth efficiency ( β ), are introduced to achieve uniformity for the comparison of nutrient uptake and growth efficiency between microalgae and macroalgae. T. subcordiformis possesses 3 times lower half saturation uptake constant, 4 times higher maximal growth rate and 20 times higher maximum specific uptake rate than U. pertusa, while U. pertusa possesses 4 times higher maximal growth efficiency than T. subcordiformis.
基金supported by Fund of Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization,Ministry of Agriculture,P.R.China(LSF2012-05)
文摘The effect of salinity on the growth and muscle nutritional quality of theExopalaemon carinicauda was studied through testing the survival rate, specific growthrate, muscle nutrient composition, amino acid composition and content by the culturingin different salinities(0-30).The results showed that the survival rate of salinity (0-30)had no significant difference (P>0.05), and the specific growth rates at salinity 15 andsalinity 20 were significantly higher than others(P>0.05); the muscle moisture contentand the crude fat content significantly decreased(P<0.05), while the muscle crudeprotein content significantly increased with an increase in the environment salinity from0 to 30(P <0.05).The crude ash content with salinity increase had a slight increase; themuscle crude protein content (18.2) at salinity 15 was significantly higher than that atsalinity 0,5, or 10(P <0.05), but there was no significant difference between salinity 15and salinity 20(P>0.05). No significant difference was found in total amino acid contentor total essential amino acid content from salinity 0 to 30(P>0.05). Total delicious aminoacid content at salinity 15-30 was significantly higher than those at salinity 0-10(P<0.05), while there was no significant difference from salinity 15 to 30(P>0.05). Theresults suggest that the suitable salinity for muscle nutritive value ranges from 15 to 30,and the Exopalaemon carinicauda can potentially be cultured above the salinity 15.
基金Item Sponsored by Swedish VINNOVA and Chinese MOST for International Colla borative Research Projects(P32737-1,P32737-2)
文摘Iron alloyed Ni3Al with composition of Ni-18. 8Ab10. 7Fe-0. 5Mn-0. 5Ti-0. 2B in atom percent （NAC alloy） showed attractive tribological properties under unlubrication condition at room temperature. The alloy was prepared by hot isostatic pressing （HIP） process. The wear properties were associated with its intrinsic deformation mechanism. Unfortunately, the single phase NAC-alloy worked inadequately with its counterpart disk, and also showed a poor machinability. In the present work, NAC-alloy matrix composite with 6 % （volume percent） MnS particle addi- tion was studied to improve its wear behaviors and performance on machining. Two metallurgical processes of HIP and vacuum casting were applied to produce the testing materials. Pin-on-disk （POD） measurements were carried out at room temperature. A commercial vermicular graphite cast iron was selected as a reference material. The counter- part disk was made of a grey cast iron as liner material in ship engines. The contact pressures of 2.83 MPa and 5.66 MPa were normally applied in the tests. The investigation indicated that MnS particle addition in the NAC-alloy composites functions as an effective solid lubricant, and improved wear properties and machinability of the materials. Obvi- ously, as-cast NAC-alloy with in-situ formed MnS-phase was working more effectively with the counterpart, compa- ring to the HIPed NAC-alloy composite with MnS particles. At the high contact pressure of 5.66 MPa, the specific wear rate of the as-cast NAC-alloy composite was high. The phenomenon of the negative effect is mostly due to the brittle second NiAl phase as evidenced in the microstructure analysis.
基金This study was supported by the National Natural Science Foundation of China(Nos.62022037,61775028,81571722,61528401 and 61921002)Guangdong province(2019ZT08Y191)+1 种基金Shenzhen Science and Technology Program(KQTD20190929172743294)Startup grant from Southern University of Science and Technology.
文摘Microwave-induced thermoacoustic imaging(MI-TAI)remains one of the focus of attention among biomedical imaging modalities over the last decade.However,the transmission and dis-tribution of microwave inside bio-tissues are complicated,thus result in severe artifacts.In this study,to reveal the underlying mechanisms of artifacts,we deeply investigate the distribution of specific absorption rate(SAR)inside tissue-mimicking phantoms with varied morphological features using both mathematical simulations and corresponding experiments.Our simulated results,which are confirmed by the associated experimental results,show that the SAR distri-bution highly depends on the geometries of the imaging targets and the polarizing features of the microwave.In addition,we propose the potential mechanisms including Mie-scattering,Fabry-Perot-feature,small curvature effect to interpret the diffraction effect in different scenarios,which may provide basic guidance to predict and distinguish the artifacts for TAI in both fundamental and clinical studies.
文摘The information extracted from monitoring of rotary blasthole drills helps to optimize the overall mining operation. Rock hardness, drillability, blastability and specific energy of drilling are examples of parameters that have been estimated in the past using measurement while drilling techniques. In order to be able to properly utilize measurement while drilling techniques, it is important to properly collect, analyze and interpret extracted data. This paper deals with processing of measurement while drilling data such as rate of penetration, rotary speed, rotary torque and pulldown force collected from rotary blasthole drills.Different methods are discussed to calculate a true rate of penetration which is the most important monitored drill variable for use in rock mass characterization. Then specific energy of drilling is defined and calculated based on electrical and mechanical inputs and the results are compared. The results show that specific energy of drilling can be estimated using the drill's primary drive systems' electrical responses with good accuracy when compared to values based on mechanical inputs.
文摘A heuristic stochastic solution of the Pennes equation is developed in this paper by applying the self-organizing, self-similar behaviour of living structures. The stochastic solution has a probability distribution that fits well with the dynamic changes in the living objects concerned and eliminates the problem of the deterministic behaviour of the Pennes approach. The solution employs the Weibull two-parametric distribution which offers satisfactory delivery of the rate of temperature change by time. Applying the method to malignant tumours obtains certain benefits, increasing the efficacy of the distortion of the cancerous cells and avoiding doing harm to the healthy cells. Due to the robust heterogeneity of these living systems, we used thermal and bioelectromagnetic effects to distinguish the malignant defects, selecting them from the healthy cells. On a selective basis, we propose an optimal protocol using the provided energy optimally such that molecular changes destroy the malignant cells without a noticeable effect on their healthy counterparts.
基金supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2012-0002231)
文摘A successful enhanced biological phosphorus removal （EBPR） was observed in both anaerobic- aerobic sequencing batch reactor （An-Ox SBR） to induce growth of phosphorus accumulating organism （PAO） and anaerobic-anoxic （An-Ax） SBR to induce growth of denitrifying PAO （DPAO）. Although the EBPR performance of An-Ox SBR was higher by 11.3% than that of An-Ax SBR, specific phosphorus release rates in the An-Ax SBR （22.8 ± 3.5 mg P/（g VSS.hr）） and the An-Ox SBR （22.4 ± 4.8 mg P/（g VSS.hr）） were similar. Specific phosphorus uptake rates under anoxic and aerobic conditions were 26.3 ± 4.8 mg P/（g VSS.hr） （An-Ax SBR） and 25.6 ± 2.8 mg P/（g VSS.hr） （An-Ox SBR）, respectively, which were also similar. In addition, an analysis of relationship of poly-β-hydroxyalkanoates （PHA） synthesized under anaerobic conditions with phosphorous release （Preleased/PHAsynthesized） and of PHA utilized under anoxic and aerobic conditions with phosphorous uptake （Puptaked/PHAutilized） verified that biological activities of EBPR per unit biomass between DPAO and PAO were similar. An analysis of the specific denitrification rate of DPAO showed that NO3-N can be denitrified at a rate that does not substantially differ from that of an ordinary denitrifier without additional consumption of organic carbon when the PHA stored inside the cell under anaerobic conditions is sufficiently secured.
