This paper reports a novel method of repetitive uniaxial compression combined with accumulative fold for preparing bulk submicron- to nanocrystalline copper starting with a coarse grained counterpart. Grain size reduc...This paper reports a novel method of repetitive uniaxial compression combined with accumulative fold for preparing bulk submicron- to nanocrystalline copper starting with a coarse grained counterpart. Grain size reduction and microstrain variations of the high purity copper samples after different passes of compression and fold are investigated by scanning electron microscope and x-ray diffraction （XRD）, respectively. Our results show that the average grain size of samples decreases from about 830 nm to 127 nm as the number of compression passes increases to 30. Microstrain in the compressed sample is found to increase for the first 20 passes, but to decrease at the last 10 passes. The variations of compressive yield strength and the shift of XRD peaks to larger diffraction angles are observed in the squeezed sample. Our experimental results demonstrate that the repetitive uniaxial compression combined with accumulative fold is an effective method to prepare bulk nanocrystalline metallic materials, in particular for soft metals such as Cu, Al and Pb.展开更多
Pearl millet at various moisture content （6.2, 9.4 and 12.3%, d.b.） and feed rates （3, 6 and 9 kg/h） was ground using hammer mill and its physical properties viz. arithmetic mean diameter, geometric mean diameter,...Pearl millet at various moisture content （6.2, 9.4 and 12.3%, d.b.） and feed rates （3, 6 and 9 kg/h） was ground using hammer mill and its physical properties viz. arithmetic mean diameter, geometric mean diameter, thousand grain weight, aspect ratio, specific surface area, surface area and bulk density were studied. Sieve analysis results showed that the increase in moisture content produced more medium sized particles with decreased percent weight retained in pan. Bond＇s work index, Kick＇s constant and average particle size were increased with the decrease in total surface area at higher moisture levels. The highest energy （2.34 KWh/kg） was consumed for 12.3% moisture content. Various grinding characteristics were significantly affected by moisture content and feed rate either individually or in combination and correlated in terms of Bond＇s work index, Kick＇s constant, total surface area, average particle size, effectiveness of milling and bulk density. Milling loss was found to be higher at lower moisture level and decreased with the increase of moisture content as well as feed rate. The loose and compact bulk density was ranged between 46.8-199.5 kg m^-3and 53.5-254.1 kg m^-3, respectively among the entire sieve fractions. Water absorption capacity increased with the decrease in particle size,展开更多
Particle wear behavior significantly affects combustion stability and operational costs. To reveal the underlying effects of particle size reduction on the heat transfer process, which are difficult to obtain experime...Particle wear behavior significantly affects combustion stability and operational costs. To reveal the underlying effects of particle size reduction on the heat transfer process, which are difficult to obtain experimentally, this study proposes a novel particle wear model. The model is experimentally calibrated and subsequently incorporated into a heat-fluid CFD-DEM platform. This is the first study to numerically investigate the impact of particle size reduction due to wear on the heat transfer characteristics in a fluidized bed. This study investigates the fluid dynamic and thermal behavior of particles after wear. It provides information on the system's macroscopic gas-solid flow regime (characterized by particle size and temperature distribution), the time-varying rules of particle wear and fragmentation rate, bed particle size distribution, and the relationship between single-particle diameter and temperature under different wear mechanisms. The primary innovation of this work lies in assessing the impact of different wear mechanisms on the key parameters (heating rate and temperature uniformity) during the heating process. Based on these findings, practical guidance is provided for optimizing industrial processes (adjusting particle flow patterns, optimizing debris distribution, and enhancing temperature monitoring at the bed bottom). The results reveal that different wear mechanisms lead to distinct distribution characteristics of particles within the bed. The abrasion mechanism enhances the heat transfer process, resulting in an approximately 16 % increase in the heating rate coefficient (C) and a 6 % improvement in temperature uniformity. In contrast, the fragmentation mechanism weakens the heat transfer process, leading to an approximately 33 % decrease in C and a 21 % reduction in temperature uniformity.展开更多
This study investigates the impact of thermophilic high solid anaerobic digestion(HS-AD)on biogas production from empty fruit bunches(EFB),focusing on the effects of total solids(TS)loading(5-40%),particle size reduct...This study investigates the impact of thermophilic high solid anaerobic digestion(HS-AD)on biogas production from empty fruit bunches(EFB),focusing on the effects of total solids(TS)loading(5-40%),particle size reduction(0.5,3.25,and 6 cm),and co-digestion with palm oil mill effluent(POME)(10-30%VS basis).The HSAD at a 15-20%TS loading has a methane yield of 103.4-105.3 mL CH_(4)/g-VS with 24.6-25.1%biodegradability.Particle size reduction to 0.5 cm enhanced methane yield by 54-61%and improved hydrolysis rates by 45%compared to the untreated EFB(6 cm)at a 15-20%TS loading.Co-digestion of EFB with POME at a ratio of 31:1 based on VS basis led to a synergistic effect of 17.77 mL CH_(4)/g-VS,increasing methane yield by 24-46.5%and improving process stability,as evidenced by a 22.8-38.1%reduction in volatile fatty acids(VFAs)accumulation.Microbial community analysis showed a 2-fold increase in the relative abundance of hydrogenotrophic methanogens(Methanothermobacter sp.and Methanoculleus sp.)during co-digestion,while the abundance of key cellulolytic bacteria(Clostridium sp.and Fibrobacter sp.)increased by 1.5-fold.The optimized HS-AD process achieved a maximum methane yield of 287.77 mL CH_(4)/g-VS and a biodegradability of 61.2%under thermophilic conditions,with a 20%POME co-digestion addition(31:1 VS ratio)and 0.5 cm particle size.These findings demonstrate the potential of thermophilic HS-AD for the sustainable management of EFB and highlight the importance of process optimization and co-digestion strategies for enhanced biogas production from EFB.展开更多
Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further he...Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.展开更多
The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever o...The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.展开更多
The multilayer structure is a promising technique used to minimize the size of planar microstrip filters.In the flexible design and incorporation of other microwave components,multilayer band-pass filter results in be...The multilayer structure is a promising technique used to minimize the size of planar microstrip filters.In the flexible design and incorporation of other microwave components,multilayer band-pass filter results in better and enhanced dimensions.This paper introduces a microstrip fifth-generation(5G)low-frequency band of 2.52–2.65 GHz using a parallel-coupled line(PCL)Bandpass filter and multilayer(ML)hairpin Bandpass filter.The targeted four-pole resonator has a center frequency of 2.585 GHz with a bandwidth of 130 MHz.The filters are designed with a 0.1 dB passband ripple with a Chebyshev response.The hairpin-line offers compact filter design structures.Theoretically,they can be obtained by bending half-wavelength resonator resonators with parallel couplings into a“U”shape.The proposed configuration of the parllel-coupled line resonator is used to design the ML band-pass filter.The FR4 substrate with a dielectric constant(Er)of 4.3 and 1.6 mm thickness was used.A comparative analysis between the simulated insertion loss and the reflection cofficient of substrates RO3003 and FR4 was performed to validate the eficiency of the proposed filter design.Simulation of PCL filter is accom-plished using computer simulation technology(CST)and an advanced design system(ADS)software.The PCL Bandpass filter was experimentally validated and a total tally between simulation results and measured results were achieved demonstrating a well-measured reflection coefficient.The simulated results obtained by the hairpin ML bandpass filter show that the circuit performs well in terms of Scattering(S)parameters and the filter size is significantly reduced.展开更多
In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. ...In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1（where λ_0 is the wavelength at 1.86 GHz in free space）. Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0（where λ_0 is the wavelength at 1.86 GHz in free space）. The proposed strategy is used for the first time to reduce the mutual coupling in E ＆ H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.展开更多
In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly a...In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation processing.We have focused on the analysis of radiation pattern,axial ratio,and design graph for the Meander line Printed Quadrifilar Helix Antenna(MPQHA).Finally,we have reduced successfully 67% size in geometry compared with traditional PQHA method,and obtained rather reasonable results.展开更多
The contribution of the inhibition of angiotensin Ⅱ (ANGⅡ) synthesis and bradykinin (BK) breakdown to the effects of ACE inhibition on infarct size, cardiac hypertrophy and blood supply to the marginal zone of the i...The contribution of the inhibition of angiotensin Ⅱ (ANGⅡ) synthesis and bradykinin (BK) breakdown to the effects of ACE inhibition on infarct size, cardiac hypertrophy and blood supply to the marginal zone of the infarcted area展开更多
Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre(DF)fraction of the feed to a large extent,increasing the accessibility of DF substrates along the gastrointestinal tract is c...Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre(DF)fraction of the feed to a large extent,increasing the accessibility of DF substrates along the gastrointestinal tract is crucial to benefit from the health stimulating metabolic end-products(e.g.butyric acid)generated upon microbial DF fermentation.Therefore,the present study aimed to evaluate the potential of reduced-particle size wheat bran(RPS-WB)and endoxylanases as feed additives to stimulate arabinoxylan(AX)hydrolysis and fermentation along the hindgut of young broilers.To this end,RPS-WB and endoxylanase supplementation were evaluated in a 2×2 factorial design using a total of 256 male 1-d-old chicks(Ross 308).Broilers were assigned to 4 dietary treatments:a basal wheat-based diet with(1)no feed additives(control,CTRL),(2)an endoxylanase(XYL;Econase XT 25 at 0.10 g/kg diet),(3)1%wheat bran with an average reduced particle size of 297μm(RPS-WB)and(4)an endoxylanase and 1%RPS-WB(RPS-WB+XYL).Each dietary treatment was replicated 8 times and on d 10 and 28,respectively,24 and 16 broilers per treatment group were euthanised to analyse AX degradation,short-chain fatty acid production and digesta viscosity in the ileum and caecum.Broilers receiving XYL in their diet showed increased AX solubilisation and fermentation at both d 10 and 28 compared to the CTRL group(P<0.05).Adding RPS-WB to the diet stimulated wheat AX utilisation by the primary AX degraders in the caecum at 10 d of age compared to the CTRL group,as observed by the high AX digestibility coefficient for the RPS-WB supplemented group at this young age(P<0.05).At 28 d,RPS-WB supplementation lowered body-weight gains but increased butyric acid concentrations compared to the XYL and CTRL group(P<0.05).Although no synergistic effect for RPS-WB+XYL broilers was observed for AX hydrolysis and fermentation,these findings suggest that both additives can raise a dual benefit to the broiler as a butyrogenic effect and improved AX fermentation along the ileum and caecum were observed throughout the broiler's life.展开更多
Previous studies highlighted the significance of optimizing the cutting blade for crop harvesting and size reduction.This study investigated the effect of blade sliding cutting angle and stem level on cutting energy o...Previous studies highlighted the significance of optimizing the cutting blade for crop harvesting and size reduction.This study investigated the effect of blade sliding cutting angle and stem level on cutting energy of single rice stem using a cutting apparatus that combined with texture analyzer.The cutting energy was determined for four blade angles.The results showed that the average cutting energy was the highest for cutting stem upper level and the lowest for cutting stem lower level.It was found that the peak cutting force per unit stem area decreased with blade sliding cutting angle increased.However,the least average cutting energy was 9.12 J/mm^(2) of 45°sliding angle when cutting without counter support blade and 32.3%less than that of 60°sliding angle.When cutting with counter support blade,the cutting energy per unit stem area varied from 6.57 to 12.54 J/mm 2 as the sliding angle varied from 0°to 60°,whereas the peak cutting force per unit stem area varied from 2.46 to 0.98 N/mm 2.It was concluded that the optimal sliding cutting angle was 45°without support blade and 30°with support blade,respectively.The experiments on rice stems in this study indicated that optimization of sliding cutting angle and stem level have a significant effect on cutting energy savings.Also this study emphasized the need to further investigate the effect of the case of more moisture content and cutting speed on the cutting energy to help in selection of optimum cutting speed and harvesting time.展开更多
A 4-kbit low-cost one-time programmable （OTP） memory macro for embedded applications is designed and implemented in a 0.18-μm standard CMOS process. The area of the proposed 1.5 transistor （1.5T） OTP cell is 2.13...A 4-kbit low-cost one-time programmable （OTP） memory macro for embedded applications is designed and implemented in a 0.18-μm standard CMOS process. The area of the proposed 1.5 transistor （1.5T） OTP cell is 2.13 μm2, which is a 49.3% size reduction compared to the previously reported cells. The 1.5T cell is fabricated and measured and shows a large programming window without any disturbance. A novel high voltage switch （HVSW） circuit is also proposed to make sure the OTP macro, implemented in a standard CMOS process, works reliably with the high program voltage. The OTP macro is embedded in negative radio frequency identification （RFID） tags. The full chip size, including the analog front-end, digital controller and the 4-kbit OTP macro, is 600 × 600 μm2. The 4-kbit OTP macro only consumes 200 × 260 μm^2. The measurement shows a 100% program yield by adjusting the program time and has obvious advantages in the core area and power consumption compared to the reported 3T and 2T OTP cores.展开更多
Despite rice bran's considerable nutritional and functional potential,its fibrous structure and high oil content complicate efforts to produce uniform,finely milled powders for food and nutraceutical applications....Despite rice bran's considerable nutritional and functional potential,its fibrous structure and high oil content complicate efforts to produce uniform,finely milled powders for food and nutraceutical applications.This study addresses that challenge by examining how milling time(30–90 min)and rotational speed(30–120 rpm)influence both the extent of particle size reduction and the associated energy demand.A laboratory ball mill was used to generate a broad range of operating conditions,while mechanical energy usage and particle-size parameters(d_(10),d_(50),d_(90))were recorded.Population Balance Modeling(PBM)served as the primary analytical framework,calibrated through experimental size distributions to yield breakage kinetics.Frictional effects were incorporated to determine net breakage energy,and classical comminution laws(Bond,Rittinger,Kick)were also evaluated for benchmarking.Results revealed two key milling regimes:an early stage with rapid fragmentation of larger particles,followed by a fine-dominated phase marked by diminished breakage rates and agglomeration.Friction-coupled PBM simulations achieved near-unity parity with experimental data,significantly improving upon simplistic energy models.Short,high-speed milling(e.g.,30 min at 120 rpm)delivered moderate fineness(d_(50)≈70–90μm)at relatively low energy(≈0.002–0.005 kWh/ton),whereas prolonged milling(≥90 min)could push median sizes below 5μm but escalated energy consumption(∼5 kWh/ton).These findings highlight the trade-off between achieving ultra-fine bran and managing rising power costs.By integrating friction-coupled PBM insights with empirical measurements,the study provides a rigorous basis for multi-objective process optimization,guiding industrial-scale rice bran milling toward both enhanced product quality and improved energy efficiency.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 50572067)
文摘This paper reports a novel method of repetitive uniaxial compression combined with accumulative fold for preparing bulk submicron- to nanocrystalline copper starting with a coarse grained counterpart. Grain size reduction and microstrain variations of the high purity copper samples after different passes of compression and fold are investigated by scanning electron microscope and x-ray diffraction （XRD）, respectively. Our results show that the average grain size of samples decreases from about 830 nm to 127 nm as the number of compression passes increases to 30. Microstrain in the compressed sample is found to increase for the first 20 passes, but to decrease at the last 10 passes. The variations of compressive yield strength and the shift of XRD peaks to larger diffraction angles are observed in the squeezed sample. Our experimental results demonstrate that the repetitive uniaxial compression combined with accumulative fold is an effective method to prepare bulk nanocrystalline metallic materials, in particular for soft metals such as Cu, Al and Pb.
文摘Pearl millet at various moisture content （6.2, 9.4 and 12.3%, d.b.） and feed rates （3, 6 and 9 kg/h） was ground using hammer mill and its physical properties viz. arithmetic mean diameter, geometric mean diameter, thousand grain weight, aspect ratio, specific surface area, surface area and bulk density were studied. Sieve analysis results showed that the increase in moisture content produced more medium sized particles with decreased percent weight retained in pan. Bond＇s work index, Kick＇s constant and average particle size were increased with the decrease in total surface area at higher moisture levels. The highest energy （2.34 KWh/kg） was consumed for 12.3% moisture content. Various grinding characteristics were significantly affected by moisture content and feed rate either individually or in combination and correlated in terms of Bond＇s work index, Kick＇s constant, total surface area, average particle size, effectiveness of milling and bulk density. Milling loss was found to be higher at lower moisture level and decreased with the increase of moisture content as well as feed rate. The loose and compact bulk density was ranged between 46.8-199.5 kg m^-3and 53.5-254.1 kg m^-3, respectively among the entire sieve fractions. Water absorption capacity increased with the decrease in particle size,
基金supported by the National Natural Science Foundation of China(grant No.:52276150).
文摘Particle wear behavior significantly affects combustion stability and operational costs. To reveal the underlying effects of particle size reduction on the heat transfer process, which are difficult to obtain experimentally, this study proposes a novel particle wear model. The model is experimentally calibrated and subsequently incorporated into a heat-fluid CFD-DEM platform. This is the first study to numerically investigate the impact of particle size reduction due to wear on the heat transfer characteristics in a fluidized bed. This study investigates the fluid dynamic and thermal behavior of particles after wear. It provides information on the system's macroscopic gas-solid flow regime (characterized by particle size and temperature distribution), the time-varying rules of particle wear and fragmentation rate, bed particle size distribution, and the relationship between single-particle diameter and temperature under different wear mechanisms. The primary innovation of this work lies in assessing the impact of different wear mechanisms on the key parameters (heating rate and temperature uniformity) during the heating process. Based on these findings, practical guidance is provided for optimizing industrial processes (adjusting particle flow patterns, optimizing debris distribution, and enhancing temperature monitoring at the bed bottom). The results reveal that different wear mechanisms lead to distinct distribution characteristics of particles within the bed. The abrasion mechanism enhances the heat transfer process, resulting in an approximately 16 % increase in the heating rate coefficient (C) and a 6 % improvement in temperature uniformity. In contrast, the fragmentation mechanism weakens the heat transfer process, leading to an approximately 33 % decrease in C and a 21 % reduction in temperature uniformity.
基金the Thailand Research Fund through grant number(RRI_PHD60I0009)the National Research Council of Thailand(NRCT)through the Talented Mid-Career Research Grant(Grant No.N41A640088)for the financial support。
文摘This study investigates the impact of thermophilic high solid anaerobic digestion(HS-AD)on biogas production from empty fruit bunches(EFB),focusing on the effects of total solids(TS)loading(5-40%),particle size reduction(0.5,3.25,and 6 cm),and co-digestion with palm oil mill effluent(POME)(10-30%VS basis).The HSAD at a 15-20%TS loading has a methane yield of 103.4-105.3 mL CH_(4)/g-VS with 24.6-25.1%biodegradability.Particle size reduction to 0.5 cm enhanced methane yield by 54-61%and improved hydrolysis rates by 45%compared to the untreated EFB(6 cm)at a 15-20%TS loading.Co-digestion of EFB with POME at a ratio of 31:1 based on VS basis led to a synergistic effect of 17.77 mL CH_(4)/g-VS,increasing methane yield by 24-46.5%and improving process stability,as evidenced by a 22.8-38.1%reduction in volatile fatty acids(VFAs)accumulation.Microbial community analysis showed a 2-fold increase in the relative abundance of hydrogenotrophic methanogens(Methanothermobacter sp.and Methanoculleus sp.)during co-digestion,while the abundance of key cellulolytic bacteria(Clostridium sp.and Fibrobacter sp.)increased by 1.5-fold.The optimized HS-AD process achieved a maximum methane yield of 287.77 mL CH_(4)/g-VS and a biodegradability of 61.2%under thermophilic conditions,with a 20%POME co-digestion addition(31:1 VS ratio)and 0.5 cm particle size.These findings demonstrate the potential of thermophilic HS-AD for the sustainable management of EFB and highlight the importance of process optimization and co-digestion strategies for enhanced biogas production from EFB.
基金the National Natural Science Foundation of China(51772042,51802294 and 51972046)Sichuan Science and Technology Plan(2017JY0348,2018FZ0100)"111"Center(B13042)。
文摘Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.
文摘The size reduction of tunable micromachined filters is carried out for high-speed wavelength tuning. We fabricated micromachined filters having a miniature structure with an air gap of 300 run and a short cantilever of 45 urn, exhibiting fast response of below 3 us.
文摘The multilayer structure is a promising technique used to minimize the size of planar microstrip filters.In the flexible design and incorporation of other microwave components,multilayer band-pass filter results in better and enhanced dimensions.This paper introduces a microstrip fifth-generation(5G)low-frequency band of 2.52–2.65 GHz using a parallel-coupled line(PCL)Bandpass filter and multilayer(ML)hairpin Bandpass filter.The targeted four-pole resonator has a center frequency of 2.585 GHz with a bandwidth of 130 MHz.The filters are designed with a 0.1 dB passband ripple with a Chebyshev response.The hairpin-line offers compact filter design structures.Theoretically,they can be obtained by bending half-wavelength resonator resonators with parallel couplings into a“U”shape.The proposed configuration of the parllel-coupled line resonator is used to design the ML band-pass filter.The FR4 substrate with a dielectric constant(Er)of 4.3 and 1.6 mm thickness was used.A comparative analysis between the simulated insertion loss and the reflection cofficient of substrates RO3003 and FR4 was performed to validate the eficiency of the proposed filter design.Simulation of PCL filter is accom-plished using computer simulation technology(CST)and an advanced design system(ADS)software.The PCL Bandpass filter was experimentally validated and a total tally between simulation results and measured results were achieved demonstrating a well-measured reflection coefficient.The simulated results obtained by the hairpin ML bandpass filter show that the circuit performs well in terms of Scattering(S)parameters and the filter size is significantly reduced.
基金Project supported by the National Natural Science Foundation of China(Grant No.61372034)
文摘In this paper, an ultra-compact single negative（SNG） electric waveguided metamaterial（WG-MTM） is first investigated and used to reduce the mutual coupling in E ＆ H planes of a dual-band microstrip antenna array. The proposed SNG electric WG-MTM unit cell is designed by etching two different symmetrical spiral lines on the ground, and has two stopbands operating at 1.86 GHz and 2.40 GHz. The circuit size is very compact, which is only λ_0/33.6 ×λ_0/15.1（where λ_0 is the wavelength at 1.86 GHz in free space）. Taking advantage of the dual-stopband property of the proposed SNG electric WG-MTM, a dual-band microstrip antenna array operating at 1.86 GHz and 2.40 GHz with very low mutual coupling is designed by embedding a cross shaped array of the proposed SNG electric WG-MTM. The measured and simulated results of the designed dual-band antenna array are in good agreement with each other, indicating that the mutual coupling of the fabricated dual-band antenna array realizes 9.8/11.1 d B reductions in the H plane, 8.5/7.9 d B reductions in the E plane at1.86 GHz and 2.40 GHz, respectively. Besides, the distance of the antenna elements in the array is only 0.35 λ_0（where λ_0 is the wavelength at 1.86 GHz in free space）. The proposed strategy is used for the first time to reduce the mutual coupling in E ＆ H planes of the dual-band microstrip antenna array by using ultra-compact SNG electric WG-MTM.
文摘In this paper,a new approach of meander line technique for Printed Quadrifilar Helix Antenna(PQHA) is studied.Compared with other meander line techniques,this approach has lowered the axial height of antenna greatly and improved the efficiency of model-building in simulation processing.We have focused on the analysis of radiation pattern,axial ratio,and design graph for the Meander line Printed Quadrifilar Helix Antenna(MPQHA).Finally,we have reduced successfully 67% size in geometry compared with traditional PQHA method,and obtained rather reasonable results.
文摘The contribution of the inhibition of angiotensin Ⅱ (ANGⅡ) synthesis and bradykinin (BK) breakdown to the effects of ACE inhibition on infarct size, cardiac hypertrophy and blood supply to the marginal zone of the infarcted area
文摘Since the caecal microbiota of young broilers are not yet able to ferment the dietary fibre(DF)fraction of the feed to a large extent,increasing the accessibility of DF substrates along the gastrointestinal tract is crucial to benefit from the health stimulating metabolic end-products(e.g.butyric acid)generated upon microbial DF fermentation.Therefore,the present study aimed to evaluate the potential of reduced-particle size wheat bran(RPS-WB)and endoxylanases as feed additives to stimulate arabinoxylan(AX)hydrolysis and fermentation along the hindgut of young broilers.To this end,RPS-WB and endoxylanase supplementation were evaluated in a 2×2 factorial design using a total of 256 male 1-d-old chicks(Ross 308).Broilers were assigned to 4 dietary treatments:a basal wheat-based diet with(1)no feed additives(control,CTRL),(2)an endoxylanase(XYL;Econase XT 25 at 0.10 g/kg diet),(3)1%wheat bran with an average reduced particle size of 297μm(RPS-WB)and(4)an endoxylanase and 1%RPS-WB(RPS-WB+XYL).Each dietary treatment was replicated 8 times and on d 10 and 28,respectively,24 and 16 broilers per treatment group were euthanised to analyse AX degradation,short-chain fatty acid production and digesta viscosity in the ileum and caecum.Broilers receiving XYL in their diet showed increased AX solubilisation and fermentation at both d 10 and 28 compared to the CTRL group(P<0.05).Adding RPS-WB to the diet stimulated wheat AX utilisation by the primary AX degraders in the caecum at 10 d of age compared to the CTRL group,as observed by the high AX digestibility coefficient for the RPS-WB supplemented group at this young age(P<0.05).At 28 d,RPS-WB supplementation lowered body-weight gains but increased butyric acid concentrations compared to the XYL and CTRL group(P<0.05).Although no synergistic effect for RPS-WB+XYL broilers was observed for AX hydrolysis and fermentation,these findings suggest that both additives can raise a dual benefit to the broiler as a butyrogenic effect and improved AX fermentation along the ileum and caecum were observed throughout the broiler's life.
基金This study was funded by the Chinese Government through the Anhui Agricultural University within a program titled“The National Key Research and Development Program of China(No.2017YFD0301303)”the China’s Ministry of Agriculture through the China Agricultural University with a program titled“China’s Ministry of Agriculture,Agricultural Public Welfare Industry Special Project(No.201503136)”.
文摘Previous studies highlighted the significance of optimizing the cutting blade for crop harvesting and size reduction.This study investigated the effect of blade sliding cutting angle and stem level on cutting energy of single rice stem using a cutting apparatus that combined with texture analyzer.The cutting energy was determined for four blade angles.The results showed that the average cutting energy was the highest for cutting stem upper level and the lowest for cutting stem lower level.It was found that the peak cutting force per unit stem area decreased with blade sliding cutting angle increased.However,the least average cutting energy was 9.12 J/mm^(2) of 45°sliding angle when cutting without counter support blade and 32.3%less than that of 60°sliding angle.When cutting with counter support blade,the cutting energy per unit stem area varied from 6.57 to 12.54 J/mm 2 as the sliding angle varied from 0°to 60°,whereas the peak cutting force per unit stem area varied from 2.46 to 0.98 N/mm 2.It was concluded that the optimal sliding cutting angle was 45°without support blade and 30°with support blade,respectively.The experiments on rice stems in this study indicated that optimization of sliding cutting angle and stem level have a significant effect on cutting energy savings.Also this study emphasized the need to further investigate the effect of the case of more moisture content and cutting speed on the cutting energy to help in selection of optimum cutting speed and harvesting time.
文摘A 4-kbit low-cost one-time programmable （OTP） memory macro for embedded applications is designed and implemented in a 0.18-μm standard CMOS process. The area of the proposed 1.5 transistor （1.5T） OTP cell is 2.13 μm2, which is a 49.3% size reduction compared to the previously reported cells. The 1.5T cell is fabricated and measured and shows a large programming window without any disturbance. A novel high voltage switch （HVSW） circuit is also proposed to make sure the OTP macro, implemented in a standard CMOS process, works reliably with the high program voltage. The OTP macro is embedded in negative radio frequency identification （RFID） tags. The full chip size, including the analog front-end, digital controller and the 4-kbit OTP macro, is 600 × 600 μm2. The 4-kbit OTP macro only consumes 200 × 260 μm^2. The measurement shows a 100% program yield by adjusting the program time and has obvious advantages in the core area and power consumption compared to the reported 3T and 2T OTP cores.
文摘Despite rice bran's considerable nutritional and functional potential,its fibrous structure and high oil content complicate efforts to produce uniform,finely milled powders for food and nutraceutical applications.This study addresses that challenge by examining how milling time(30–90 min)and rotational speed(30–120 rpm)influence both the extent of particle size reduction and the associated energy demand.A laboratory ball mill was used to generate a broad range of operating conditions,while mechanical energy usage and particle-size parameters(d_(10),d_(50),d_(90))were recorded.Population Balance Modeling(PBM)served as the primary analytical framework,calibrated through experimental size distributions to yield breakage kinetics.Frictional effects were incorporated to determine net breakage energy,and classical comminution laws(Bond,Rittinger,Kick)were also evaluated for benchmarking.Results revealed two key milling regimes:an early stage with rapid fragmentation of larger particles,followed by a fine-dominated phase marked by diminished breakage rates and agglomeration.Friction-coupled PBM simulations achieved near-unity parity with experimental data,significantly improving upon simplistic energy models.Short,high-speed milling(e.g.,30 min at 120 rpm)delivered moderate fineness(d_(50)≈70–90μm)at relatively low energy(≈0.002–0.005 kWh/ton),whereas prolonged milling(≥90 min)could push median sizes below 5μm but escalated energy consumption(∼5 kWh/ton).These findings highlight the trade-off between achieving ultra-fine bran and managing rising power costs.By integrating friction-coupled PBM insights with empirical measurements,the study provides a rigorous basis for multi-objective process optimization,guiding industrial-scale rice bran milling toward both enhanced product quality and improved energy efficiency.
