The Santos Basin in Brazil has witnessed significant oil and gas discoveries in deepwater pre-salt since the 21^(st)century.Currently,the waters in eastern Brazil stand out as a hot area of deepwater exploration and p...The Santos Basin in Brazil has witnessed significant oil and gas discoveries in deepwater pre-salt since the 21^(st)century.Currently,the waters in eastern Brazil stand out as a hot area of deepwater exploration and production worldwide.Based on a review of the petroleum exploration and production history in Brazil,the challenges,researches and practices,strategic transformation,significant breakthroughs,and key theories and technologies for exploration from onshore to offshore and from shallow waters to deep-ultra-deep waters and then to pre-salt strata are systematically elaborated.Within 15 years since its establishment in 1953,Petrobras explored onshore Paleozoic cratonic and marginal rift basins,and obtained some small to medium petroleum discoveries in fault-block traps.In the 1970s,Petrobras developed seismic exploration technologies and several hydrocarbon accumulation models,for example,turbidite sandstones,allowing important discoveries in shallow waters,e.g.the Namorado Field and Enchova fields.Guided by these models/technologies,significant discoveries,e.g.the Marlim and Roncador fields,were made in deepwater post-salt in the Campos Basin.In the early 21^(st)century,the advancements in theories and technologies for pre-salt petroleum system,carbonate reservoirs,hydrocarbon accumulation and nuclear magnetic resonance(NMR)logging stimulated a succession of valuable discoveries in the Lower Cretaceous lacustrine carbonates in the Santos Basin,including the world-class ultra-deepwater super giant fields such as Tupi(Lula),Mero and Buzios.Petroleum development in complex deep water environments is extremely challenging.By establishing the Technological Capacitation Program in Deep Waters(PROCAP),Petrobras developed and implemented key technologies including managed pressure drilling(MPD)with narrow pressure window,pressurized mud cap drilling(PMCD),multi-stage intelligent completion,development with Floating Production Storage and Offloading units(FPSO),and flow assurance,which remarkably improved the drilling,completion,field development and transportation efficiency and safety.Additionally,under the limited FPSO capacity,Petrobras promoted the world-largest CCUS-EOR project,which contributed effectively to the reduction of greenhouse gas emissions and the enhancement of oil recovery.Development and application of these technologies provide valuable reference for deep and ultra-deepwater petroleum exploration and production worldwide.The petroleum exploration in Brazil will consistently focus on ultra-deep water pre-salt carbonates and post-salt turbidites,and seek new opportunities in Paleozoic gas.Technical innovation and strategic cooperation will be held to promote the sustainable development of Brazil's oil and gas industry.展开更多
Coccidiosis is a disease caused by intracellular protozoan parasites, specifically belonging to the genus Eimeria. These parasites target the gastrointestinal tract in different types of hosts, causing sores in the in...Coccidiosis is a disease caused by intracellular protozoan parasites, specifically belonging to the genus Eimeria. These parasites target the gastrointestinal tract in different types of hosts, causing sores in the intestinal lining. The presence of these lesions reduces the animal’s ability to digest and absorb nutrients, significantly impacting their overall performance. The current study aimed to explore the potential correlation between seasonal variations and the incidence of Eimeria spp-induced lesions in broiler chickens’ gastrointestinal tracts in Brazil from 2012 to 2018. A total of 8,607 broiler chickens, aged 14 to 42 days, were sampled from 103 poultry integrated companies in Brazil to conduct intestinal health examinations. The sampling process involved selecting 3 to 6 chickens from each poultry house for examination. The assessment included various abnormalities such as shedding of intestinal cells and excessive fluid and mucus presence, thickening and tension of the intestines, food movement, roughened mucosal surface resembling a Turkish towel in the small intestine, tissue death, duodenal inflammation, intestinal inflammation, gizzard erosion, presence of worms and bedding material, and ingestion of mealworms. During the seasons, winter exhibited the highest average occurrence of Eimeria maxima microorganisms at 52.83%, with E. acervulina following closely at 26.42% in second place. In spring, E. maxima had an occurrence of 11.31%, while in fall, E. tenella had the lowest occurrence at 6.74%. When analyzing the seasonal occurrence of Eimeria, it was observed that E. maxima micro was more common during winter compared to summer (P = 0.0491). However, no discernible variation was observed in the occurrence of the remaining species across different seasons. Research findings suggest that subclinical coccidiosis is most prevalent during the winter season in Brazil. Likewise, clinical disease caused by E. acervulina is also prevalent during this time. In contrast, E. maxima is more likely to cause clinical disease in the spring, whereas E. tenella is more commonly associated with clinical disease in the fall. Lesions induced by Eimeria spp. are associated with factors influencing the overall health of broiler intestines. These findings allow for the utilization of seasonal metrics in disease management, thereby reducing economic losses associated with the condition.展开更多
In the aftermath of the coronavirus disease 2019(COVID-19)pandemic in Brazil,accountability is crucial for those who denied the severity of the virus,spreading false information and causing harm.Some individuals have ...In the aftermath of the coronavirus disease 2019(COVID-19)pandemic in Brazil,accountability is crucial for those who denied the severity of the virus,spreading false information and causing harm.Some individuals have already faced legal proceedings against them,revealing economic motivations behind their actions.It is equally important to hold doctors accountable for prescribing ineffective treatments,putting the population at risk.The leaders of the denial movement and the federal government,who mishandled the pandemic,should be held accountable for the high death toll.Seeking justice from the legislative and executive branches is necessary,along with exemplary measures for those who spread misinformation about COVID-19.展开更多
The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazi...The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazil basic interest rate is denominated Selic.The application of these policies requires the protagonist of bank’s financial intermediation.This study aims to verify two events-under the perspective of the efficient markets’theory.The first is the communication of the first death by COVID-19-and the subsequent,Selic rate reduction to 2%p.a.-and its effects on bank’s shares prices.The hypotheses presented are:H1-The announcement of the first death by COVID-19 negatively impacts the banks’shares returns and H2-The announcement of the Selic interest rate-during the COVID-19-positively impacts the return of the banks’shares.We adopt event study methodology in a final sample of nine and 15 banks to Events 1 and 2 respectively.The results confirm H1 as well as the semi-strong informational efficiency market.H2 is not confirmed.Results confirm the non-effectiveness of the anticyclical policy of basic interest rate reduction.This contributes to the discussion about the impacts of COVID-19 and the efficacy of anticyclical policies.展开更多
Brazil possesses abundant new energy resources such as solar energy,wind energy,and biomass energy,and is at the forefront of the world in the development and utilization of new energy,becoming a pioneer in energy tra...Brazil possesses abundant new energy resources such as solar energy,wind energy,and biomass energy,and is at the forefront of the world in the development and utilization of new energy,becoming a pioneer in energy transition and low-carbon development.Renewable energy accounts for nearly half of Brazil’s primary energy consumption,with the share in the power sector exceeding 75%.Brazil has achieved its carbon peak and is still actively promoting carbon and emission further reduction and the development of new energy.展开更多
[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test material...[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels (5%,10% and 15%) and time periods (24,48 and 72 h).[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline (Pro) in seedling leaves from high to low was PEG15%,PEG10% and PEG5%; the content of treatment of 5% stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows:PEG15%>PEG10%>PEG5%,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5% of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows:PEG10%>PEG15%>PEG5% and the activity increased remarkably in the group with PEG at 5% within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.展开更多
To reveal stress distribution and crack propagation of Brazilian discs under impact loads, dynamic tests were conducted with SHPB (split Hopkinson pressure bar) device. Stress states of specimens were monitored with...To reveal stress distribution and crack propagation of Brazilian discs under impact loads, dynamic tests were conducted with SHPB (split Hopkinson pressure bar) device. Stress states of specimens were monitored with strain gauges on specimen surface and SHPB bars. The failure process of specimen was recorded by ultra speed camera FASTCAM SAI.1 (675 000 fps). Stress histories from strain gauges offer comprehensive information to evaluate the stress equilibrium of specimen in time and space. When a slowly rising load (with loading rates less than 1 200 N/s for d 50 mm bar) is applied, there is usually good stress equilibrium in specimen. The stress distribution after equilibrium is similar to its static counterpart. And the first crack initiates at the disc center and propagates along the load direction. But with the front of incident wave becoming steep, it is hard for specimens to get to stress equilibrium. The first crack may appear anywhere on the specimen together with multiple randomly distributed secondary cracks. For a valid dynamic Brazil test with stress equilibrium, the specimen will break into two halves neatly. While for tests with stress disequilibrium, missing strap may be found when broken halves of specimens are put together. For those specimens broken up neatly at center but having missing wedges at the loading areas, it is usually subjected to local buckling from SHPB bars.展开更多
Fertilizer effect model such as ternary quadratic, unary quadratic, straight line and platform model was respectively used to analyze the two-year "3414" test data collected from banana garden in Fushan Town of Hain...Fertilizer effect model such as ternary quadratic, unary quadratic, straight line and platform model was respectively used to analyze the two-year "3414" test data collected from banana garden in Fushan Town of Hainan Province. The results showed that the optimal fertilizing amount of ternary quadratic model simulation was0.374 kg/plant of N, 0.289 kg/plant of P2O5 and 0.891 kg/plant of K2 O. According to the yield trend characteristic, the optimal fertilizing amount of unary quadratic model was 0.400kg/plant of N, 0.214 kg/plant of P2O5 and 0.901kg/plant of K2 O. Thus it can be seen that only partial indices of the optimal fertilizing amount of ternary quadratic model simulation were higher than that of unary quadratic model. Considering the results, the optimal fertilizing amount of Brazil banana was 0.374-0.400kg/plant of N, 0.214-0.289 kg/plant of P2O5 and 0.891-0.901 kg/plant of K2 O.展开更多
This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid gro...This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.展开更多
A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand& plantations in the semiarid region ( 15...A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand& plantations in the semiarid region ( 15° 09′ S 43° 49′ W) in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass (dry matter) was 33.6 Mg.ha^-1 for E. camaldulensis and 53.1 Mg·ha^-1 for E. grandis. The biomass of the stem wood, leaves, branches, and stein bark for E. camaldulens accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively (Table 2); meanwhile a similar partition of the total above-ground biomass was also found for E. grand&. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk (bark and wood), nutrient accumulation in general was lower. Nutrient content of E. grand& presented little variation compared with that orE. camaJd^llensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grand&. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy.展开更多
AIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer. METHODS:We conducte...AIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer. METHODS:We conducted a study on 100 cases of gastric cancer (GC),100 cases of chronic gastritis (CG),and 150 controls (C).Deletion of the GSTT1 and GSTM1 genes was assessed by multiplex PCR.CYP2E1/Pst1 genotyping was performed using a PCR-RFLP assay. RESULTS:No relationship between GSTT1/GSTM1 deletion and the c1/c2 genotype of CYP2E1 was observed among the three groups.However,a significant difference between CG and C was observed,due to a greater number of GSTT1/GSTM1 positive genotypes in the CG group.The GSTT1 null genotype occurred more frequently in Negroid subjects,and the GSTM1 null genotype in Caucasians,while the GSTM1 positive genotype was observed mainly in individuals with chronic gastritis infected with H pylori. CONCLUSION:Our findings indicate that there is no obvious relationship between the GSTT1,GSTM1 and CYP2E1 polymorphisms and gastric cancer.展开更多
Wide area measurement system(WAMS), which is based on synchronization data from phasor measurement units(PMU) and EMS SCADA, is implemented to establish a system model that can handle certain functions such as realtim...Wide area measurement system(WAMS), which is based on synchronization data from phasor measurement units(PMU) and EMS SCADA, is implemented to establish a system model that can handle certain functions such as realtime power system monitoring, oscillation mode analysis, accident analysis and decision-making assistance for emergency control. The Brazilian Interconnected Power System(BIPS) is a large system covering an extensive geographical region, which faces certain risks and challenges. It has several main transmission corridors associated with large power plants and interconnection between the northern and southeastern regions. Mismatch between the energy base and load pool also exists in Brazil as energy resources are not well-distributed; therefore, the use of large-capacity, long-distance transmission technique to transmit remote power is unescapable. On the other hand, there are many types of voltage levels and multiple entangled electromagnetic loops owing to historical reasons. Then, for insufficient power reservation and defective grid body in load pools, once the external power is cut, it's easy to raise a blackout. The infrastructure is old and the power system operates close to the upper limit. All these represent risks and challenges to BIPS. Through WAMS technology research method in this project, the electrical power system function of monitoring, analysis, and control improved from the static state to the dynamic state. WAMS enhances data integration and real-time analysis capabilities, and can provide dispatchers with high quality real-time dynamic information and decision-making support information, enhance monitoring of auxiliary services in the electricity market, enable operators to improve the accuracy of power network analysis, thereby increasing power grid monitoring and operation, and improve the transmission capacity and reliability of the power grid operation [1].展开更多
Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic st...Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, but the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units (areas of endemism) and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora.展开更多
Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial c...Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial crests in pterodactyloids were sexually dimorphic and are thought to have evolved in adult males in response to female mate choice. However, the location of cranial crests in front of the center of gravity would create instability in the yaw axis during flight and may seem like a handicap. Vertically aligned webbed feet probably suppressed the yawing rotations and instability from the crest. Here we show that the crest functioned as a front rudder to make agile turn and mediate flight control. A computer simulation model suggests that Tapejara had a large excess of muscle power available above the power required for continuous flapping flight. It could easily takeoff from a perch, ground, or water surface and land safely on the ground. It was an excellent glider with a gliding angle close to 4~ and a cruising speed of 27 km/h. Tapejara could soar efficiently on the windward side of cliffs or circle on rising thermals over tropical waters for efficient long-distance flight. Various control surfaces in the wings of Tapejara analogous to the slat, aileron, elevator, fin, rudder, and horizontal stabilizer of an aircraft made pterodactyloids versatile flyers.展开更多
BALB/c mice were intraperitoneally injected with 10, 5 or 2.5 mg/kg Brazil for 14 days after sciatic nerve injury. Results demonstrate that the spleen T/B lymphocyte stimulation index and serum circulating immune comp...BALB/c mice were intraperitoneally injected with 10, 5 or 2.5 mg/kg Brazil for 14 days after sciatic nerve injury. Results demonstrate that the spleen T/B lymphocyte stimulation index and serum circulating immune complex concentration were significantly reduced, and the morphology of the soleus muscle was restored in mice with sciatic nerve injury. These effects of Brazil were dose-dependent. Our experimental findings indicate that Brazil can regulate immune responses after nerve injury and promote sciatic nerve repair.展开更多
The Venda Nova Pluton (VNP) is a zoned ring structure emplaced in the southern portion of the Neoproterozoic Araquai Belt, in Espirito Santo, Brazil. It is a slightly westward tilted cylinder-like intrusion, with an...The Venda Nova Pluton (VNP) is a zoned ring structure emplaced in the southern portion of the Neoproterozoic Araquai Belt, in Espirito Santo, Brazil. It is a slightly westward tilted cylinder-like intrusion, with an almost circular horizontal section. In the center of this structure, an off-centered gabbro-noritic core, surrounded by syeno-monzonitic rocks, intrudes an outer ring of charnockites and norite. These envelop the syeno-monzonitic and gabbro-noritic center, as a narrow discontinuous belt. While, in the core intrusion, mingling and mixing processes are widespread and well documented in the literature, in the outer ring, the norite and charnockite layers show predominantly homogeneous and isotropic internal structures. Nevertheless, smaller interaction zones between charnockites and norite denote a comparatively more restricted mingling process. The norite is a fine-grained rock with hypidio- morphic granular to intergranular texture. The charnockites are medium-grained and made up of: (a) orthopyroxene-tonalite, (h) orthopyroxene-quartz-diorite, and (c) orthopyroxene-granodiorite with hy- pidiomorphic granular to porphyritic textures. In all lithotypes both ortho- and clinopyroxene are replaced by hornblende and biotite. Two contrasting compositional sequences have been recognized, based on whole rock geochemistry: (1) a basic, with tholeiitic affinities (norite) and, (2) an intermediate, medium-K calc-alkalinc, comprising the charnockites. Estimated crystallization temperatures, which have been calculated from micro-probe analysis of pyroxenes, range from 915± 25 ℃ to 960 ± 50 ℃. Re-equilibration temperature (ihnenite-magnetite calibration) is around 600 ~ 50 ℃. This indicates oxygen fugacities four order of magnitude below the FMQ-buffer and a reduced environment. Coeval pressure conditions estimated from the Al-content in hornblende range from 5.5 ± 0.6 kbar. Data obtained for the norite point toward an evolution from the partial melting of an anhydrous tholeiitic mantle magma. The charnockites may correspond to the differentiation of a calc-alkaline parental magma. The later could be the hybrid product from the contamination and mixing between the anhydrous tholeiitic magma with other deeper crustal sources. Further the magmatic system evolved through frac- tionation of orthopyroxene, clinopyroxene, plagioclase and ilnlenite. Our results support the hypothesis for the evolution of the Venda Nova Pluton through a mantle-crust delamination process probably related to the collapse of the Araquai orogeny.展开更多
This survey investigated the relationship between executive compensation and the financial performance of companies. It is hypothesized that a company can utilize its pay system to direct executives' efforts toward i...This survey investigated the relationship between executive compensation and the financial performance of companies. It is hypothesized that a company can utilize its pay system to direct executives' efforts toward its strategic business objectives, thus contributing to higher levels of corporate financial performance. The survey data consisted of a secondary and non-probabilistic sample of 44 Brazilian industrial companies. In order to operationalize the independent remuneration variable, the authors used average monthly salary, average variable salary, and three indices that were created for this survey: benefits, career, and development. These indices measure the access to benefits, mechanisms for stimulating and supporting careers, and mechanisms to encourage education and professional development that companies offer to their directors, vice presidents, and chief executive officers (CEOs), who are referred to in this paper by the term "executive". The remuneration data are from fiscal year 2006. In order to operationalize the financial performance variable, two accounting indicators were used: sales growth and return on equity (ROE) for fiscal years 2006 and 2007. The size of the companies was used as a control variable. The results of a multiple regression analysis do not support the hypothesis that there is a positive and significant relationship between executive compensation and corporate financial performance.展开更多
AIM: To determine hepatitis C virus (HCV) seropreva- lence and its genotypes, and to identify the factors associated with HCV infection. METHODS: This cross-sectional study, conducted in two prisons (one male and...AIM: To determine hepatitis C virus (HCV) seropreva- lence and its genotypes, and to identify the factors associated with HCV infection. METHODS: This cross-sectional study, conducted in two prisons (one male and one female) in the State of Ser- gipe, Brazil, comprised 422 subjects. All of the prisoners underwent a rapid test for the detection of HCV antibod- ies. Patient~ with a positive result were tested for anti- HCV by enzyme linked immunosorbent assay and for HCV RNA by qualitative polymerase chain reaction (PCR). The virus genotype was defined in every serum sample that presented positive for PCR-HCV. In order to determine the factors independently associated with positive serol- ogy for HCV, multivariate logistic regression was used. RESULTS: HCV seroprevalence was 3.1%. Of the 13 subjects with positive anti-HCV, 11 had viremia confirmed by PCR. Of these, 90.9% had genotype 1. A total of 43 (10.2%) were injecting drug users, and HCV seroprevalence in this subgroup was 20.6%. The variable most strongly associated with positive serology for HCV was use of injecting drugs [odds ratio (OR), 23.3; 95% confidence interval (CI), 6.0-90.8]. Age over 30 years (OR, 5.5; 95%CI, 1.1-29.2), history of syphilis (OR, 9.8; 95%CI, 1.7-55.2) and history of household contact with HCV positive individual (OR, 14.1; 95%CI, 2.3-85.4) were also independently associated with HCV infection. CONCLUSION: Most of the HCV transmissions result from parenteral exposure. However, there is evidence to suggest a role for sex and household contact with an infected subject in virus transmission.展开更多
We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underl...We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underlying physical mechanism governing the motion of the intruder.Within the acceleration range of 3.5 g≥Γ≥1.5 g,we find that,regardless of the intruder's initial position,it consistently reaches the same equilibrium depth when the vibration acceleration(Γ)and frequency(ω)are fixed.ForΓ≤2.5 g,the equilibrium position lies on the surface of the granular bed,while forΓ>2.5 g,it shifts below the surface.Additionally,intruders with different densities exhibit varying equilibrium depths,with higher density resulting in a deeper equilibrium position.To understand the mechanism behind the intruder's upward or downward motion,we measure its rising or sinking velocities under different vibration parameters.Our findings demonstrate that the rising velocity of the intruder,under varying vibration accelerations(Γ)and frequencies(ω),can be collapsed using the ratioΓ/ω,while the sinking velocity remains unaffected by the vibration strength.This confirms that the upward motion of the larger sphere,associated with the Brazil nut effect,primarily arises from the void-filling mechanism of the bed particles.Furthermore,our experiments reveal that the presence of convection within the bed particles has minimal impact on the motion of the intruder.展开更多
New variola(NV)-mpox(monkeypox)-is a zoonosis caused by the mpox virus,which belongs to the genus Orthopoxvirus in the family Poxviridae.This disease,in the present year(2022),has caused several cases and deaths aroun...New variola(NV)-mpox(monkeypox)-is a zoonosis caused by the mpox virus,which belongs to the genus Orthopoxvirus in the family Poxviridae.This disease,in the present year(2022),has caused several cases and deaths around the world,including Brazil[1].The group of poxviruses,in which the species that causes NV is included,consists of agents widely distributed in nature.Due to their considerably large size,they were among the first viruses to be microscopically visualized.The Poxviridae family is capable of infecting epithelial and connective tissue cells.Currently,such a viral family is classified as a genome lineage composed of doublestranded DNA,completely independent of the host nucleus[1].展开更多
文摘The Santos Basin in Brazil has witnessed significant oil and gas discoveries in deepwater pre-salt since the 21^(st)century.Currently,the waters in eastern Brazil stand out as a hot area of deepwater exploration and production worldwide.Based on a review of the petroleum exploration and production history in Brazil,the challenges,researches and practices,strategic transformation,significant breakthroughs,and key theories and technologies for exploration from onshore to offshore and from shallow waters to deep-ultra-deep waters and then to pre-salt strata are systematically elaborated.Within 15 years since its establishment in 1953,Petrobras explored onshore Paleozoic cratonic and marginal rift basins,and obtained some small to medium petroleum discoveries in fault-block traps.In the 1970s,Petrobras developed seismic exploration technologies and several hydrocarbon accumulation models,for example,turbidite sandstones,allowing important discoveries in shallow waters,e.g.the Namorado Field and Enchova fields.Guided by these models/technologies,significant discoveries,e.g.the Marlim and Roncador fields,were made in deepwater post-salt in the Campos Basin.In the early 21^(st)century,the advancements in theories and technologies for pre-salt petroleum system,carbonate reservoirs,hydrocarbon accumulation and nuclear magnetic resonance(NMR)logging stimulated a succession of valuable discoveries in the Lower Cretaceous lacustrine carbonates in the Santos Basin,including the world-class ultra-deepwater super giant fields such as Tupi(Lula),Mero and Buzios.Petroleum development in complex deep water environments is extremely challenging.By establishing the Technological Capacitation Program in Deep Waters(PROCAP),Petrobras developed and implemented key technologies including managed pressure drilling(MPD)with narrow pressure window,pressurized mud cap drilling(PMCD),multi-stage intelligent completion,development with Floating Production Storage and Offloading units(FPSO),and flow assurance,which remarkably improved the drilling,completion,field development and transportation efficiency and safety.Additionally,under the limited FPSO capacity,Petrobras promoted the world-largest CCUS-EOR project,which contributed effectively to the reduction of greenhouse gas emissions and the enhancement of oil recovery.Development and application of these technologies provide valuable reference for deep and ultra-deepwater petroleum exploration and production worldwide.The petroleum exploration in Brazil will consistently focus on ultra-deep water pre-salt carbonates and post-salt turbidites,and seek new opportunities in Paleozoic gas.Technical innovation and strategic cooperation will be held to promote the sustainable development of Brazil's oil and gas industry.
文摘Coccidiosis is a disease caused by intracellular protozoan parasites, specifically belonging to the genus Eimeria. These parasites target the gastrointestinal tract in different types of hosts, causing sores in the intestinal lining. The presence of these lesions reduces the animal’s ability to digest and absorb nutrients, significantly impacting their overall performance. The current study aimed to explore the potential correlation between seasonal variations and the incidence of Eimeria spp-induced lesions in broiler chickens’ gastrointestinal tracts in Brazil from 2012 to 2018. A total of 8,607 broiler chickens, aged 14 to 42 days, were sampled from 103 poultry integrated companies in Brazil to conduct intestinal health examinations. The sampling process involved selecting 3 to 6 chickens from each poultry house for examination. The assessment included various abnormalities such as shedding of intestinal cells and excessive fluid and mucus presence, thickening and tension of the intestines, food movement, roughened mucosal surface resembling a Turkish towel in the small intestine, tissue death, duodenal inflammation, intestinal inflammation, gizzard erosion, presence of worms and bedding material, and ingestion of mealworms. During the seasons, winter exhibited the highest average occurrence of Eimeria maxima microorganisms at 52.83%, with E. acervulina following closely at 26.42% in second place. In spring, E. maxima had an occurrence of 11.31%, while in fall, E. tenella had the lowest occurrence at 6.74%. When analyzing the seasonal occurrence of Eimeria, it was observed that E. maxima micro was more common during winter compared to summer (P = 0.0491). However, no discernible variation was observed in the occurrence of the remaining species across different seasons. Research findings suggest that subclinical coccidiosis is most prevalent during the winter season in Brazil. Likewise, clinical disease caused by E. acervulina is also prevalent during this time. In contrast, E. maxima is more likely to cause clinical disease in the spring, whereas E. tenella is more commonly associated with clinical disease in the fall. Lesions induced by Eimeria spp. are associated with factors influencing the overall health of broiler intestines. These findings allow for the utilization of seasonal metrics in disease management, thereby reducing economic losses associated with the condition.
文摘In the aftermath of the coronavirus disease 2019(COVID-19)pandemic in Brazil,accountability is crucial for those who denied the severity of the virus,spreading false information and causing harm.Some individuals have already faced legal proceedings against them,revealing economic motivations behind their actions.It is equally important to hold doctors accountable for prescribing ineffective treatments,putting the population at risk.The leaders of the denial movement and the federal government,who mishandled the pandemic,should be held accountable for the high death toll.Seeking justice from the legislative and executive branches is necessary,along with exemplary measures for those who spread misinformation about COVID-19.
文摘The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazil basic interest rate is denominated Selic.The application of these policies requires the protagonist of bank’s financial intermediation.This study aims to verify two events-under the perspective of the efficient markets’theory.The first is the communication of the first death by COVID-19-and the subsequent,Selic rate reduction to 2%p.a.-and its effects on bank’s shares prices.The hypotheses presented are:H1-The announcement of the first death by COVID-19 negatively impacts the banks’shares returns and H2-The announcement of the Selic interest rate-during the COVID-19-positively impacts the return of the banks’shares.We adopt event study methodology in a final sample of nine and 15 banks to Events 1 and 2 respectively.The results confirm H1 as well as the semi-strong informational efficiency market.H2 is not confirmed.Results confirm the non-effectiveness of the anticyclical policy of basic interest rate reduction.This contributes to the discussion about the impacts of COVID-19 and the efficacy of anticyclical policies.
文摘Brazil possesses abundant new energy resources such as solar energy,wind energy,and biomass energy,and is at the forefront of the world in the development and utilization of new energy,becoming a pioneer in energy transition and low-carbon development.Renewable energy accounts for nearly half of Brazil’s primary energy consumption,with the share in the power sector exceeding 75%.Brazil has achieved its carbon peak and is still actively promoting carbon and emission further reduction and the development of new energy.
文摘[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana (Musa AAA Cavendish subgroup cv.Brazil) was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels (5%,10% and 15%) and time periods (24,48 and 72 h).[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline (Pro) in seedling leaves from high to low was PEG15%,PEG10% and PEG5%; the content of treatment of 5% stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows:PEG15%>PEG10%>PEG5%,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5% of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows:PEG10%>PEG15%>PEG5% and the activity increased remarkably in the group with PEG at 5% within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.
基金Projects(50904079, 51274254, 50934006) supported by the National Natural Science Foundation of ChinaProject(2010CB732004) supported by the National Basic Research Program of ChinaProject(NCET-11-0528) supported by Program for New Century Excellent Talents in University of China
文摘To reveal stress distribution and crack propagation of Brazilian discs under impact loads, dynamic tests were conducted with SHPB (split Hopkinson pressure bar) device. Stress states of specimens were monitored with strain gauges on specimen surface and SHPB bars. The failure process of specimen was recorded by ultra speed camera FASTCAM SAI.1 (675 000 fps). Stress histories from strain gauges offer comprehensive information to evaluate the stress equilibrium of specimen in time and space. When a slowly rising load (with loading rates less than 1 200 N/s for d 50 mm bar) is applied, there is usually good stress equilibrium in specimen. The stress distribution after equilibrium is similar to its static counterpart. And the first crack initiates at the disc center and propagates along the load direction. But with the front of incident wave becoming steep, it is hard for specimens to get to stress equilibrium. The first crack may appear anywhere on the specimen together with multiple randomly distributed secondary cracks. For a valid dynamic Brazil test with stress equilibrium, the specimen will break into two halves neatly. While for tests with stress disequilibrium, missing strap may be found when broken halves of specimens are put together. For those specimens broken up neatly at center but having missing wedges at the loading areas, it is usually subjected to local buckling from SHPB bars.
基金Supported by the National Science Found for Young Scholars of China(No.31101123)Natural Science Foundation of Hainan Province of China(No.311062)~~
文摘Fertilizer effect model such as ternary quadratic, unary quadratic, straight line and platform model was respectively used to analyze the two-year "3414" test data collected from banana garden in Fushan Town of Hainan Province. The results showed that the optimal fertilizing amount of ternary quadratic model simulation was0.374 kg/plant of N, 0.289 kg/plant of P2O5 and 0.891 kg/plant of K2 O. According to the yield trend characteristic, the optimal fertilizing amount of unary quadratic model was 0.400kg/plant of N, 0.214 kg/plant of P2O5 and 0.901kg/plant of K2 O. Thus it can be seen that only partial indices of the optimal fertilizing amount of ternary quadratic model simulation were higher than that of unary quadratic model. Considering the results, the optimal fertilizing amount of Brazil banana was 0.374-0.400kg/plant of N, 0.214-0.289 kg/plant of P2O5 and 0.891-0.901 kg/plant of K2 O.
文摘This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.
基金financed by CAPES (Coordenao de Aperfeioamento de Pessoal de Nível Superior)
文摘A study was conducted to evaluate the aboveground biomass, nutrient content and the percentages of mycorrhizal colonization in Eucalyptus camaldulensis and Eucalyptus grand& plantations in the semiarid region ( 15° 09′ S 43° 49′ W) in the north of the State of Minas Gerais in Brazil. Results show that the total above-ground biomass (dry matter) was 33.6 Mg.ha^-1 for E. camaldulensis and 53.1 Mg·ha^-1 for E. grandis. The biomass of the stem wood, leaves, branches, and stein bark for E. camaldulens accounted for 64.4%, 19.6%, 15.4%, and 0.6% of the total biomass, respectively (Table 2); meanwhile a similar partition of the total above-ground biomass was also found for E. grand&. The dry matter of leaves and branches of E. camaldulensis accounted for 35% of total biomass, and the contents of N, P, K, Ca, Mg, and S in leaves and branches accounted for 15.5%, 0.7%, 12.3%, 22.6%, 1.9%, and 1.4% of those in total above-ground biomass, respectively. In the trunk (bark and wood), nutrient accumulation in general was lower. Nutrient content of E. grand& presented little variation compared with that orE. camaJd^llensis. Wood localized in superior parts of trunk presented a higher concentration of P and bark contained significant amounts of nutrients, especially in E. grand&. This indicated that leaving vegetal waste is of importance on the site in reducing the loss of tree productivity in this semi-arid region. The two species showed mycotrophy.
文摘AIM:To test the hypothesis that,in the Southeastern Brazilian population,the GSTT1,GSTM1 and CYP2E1 polymorphisms and putative risk factors are associated with an increased risk for gastric cancer. METHODS:We conducted a study on 100 cases of gastric cancer (GC),100 cases of chronic gastritis (CG),and 150 controls (C).Deletion of the GSTT1 and GSTM1 genes was assessed by multiplex PCR.CYP2E1/Pst1 genotyping was performed using a PCR-RFLP assay. RESULTS:No relationship between GSTT1/GSTM1 deletion and the c1/c2 genotype of CYP2E1 was observed among the three groups.However,a significant difference between CG and C was observed,due to a greater number of GSTT1/GSTM1 positive genotypes in the CG group.The GSTT1 null genotype occurred more frequently in Negroid subjects,and the GSTM1 null genotype in Caucasians,while the GSTM1 positive genotype was observed mainly in individuals with chronic gastritis infected with H pylori. CONCLUSION:Our findings indicate that there is no obvious relationship between the GSTT1,GSTM1 and CYP2E1 polymorphisms and gastric cancer.
文摘Wide area measurement system(WAMS), which is based on synchronization data from phasor measurement units(PMU) and EMS SCADA, is implemented to establish a system model that can handle certain functions such as realtime power system monitoring, oscillation mode analysis, accident analysis and decision-making assistance for emergency control. The Brazilian Interconnected Power System(BIPS) is a large system covering an extensive geographical region, which faces certain risks and challenges. It has several main transmission corridors associated with large power plants and interconnection between the northern and southeastern regions. Mismatch between the energy base and load pool also exists in Brazil as energy resources are not well-distributed; therefore, the use of large-capacity, long-distance transmission technique to transmit remote power is unescapable. On the other hand, there are many types of voltage levels and multiple entangled electromagnetic loops owing to historical reasons. Then, for insufficient power reservation and defective grid body in load pools, once the external power is cut, it's easy to raise a blackout. The infrastructure is old and the power system operates close to the upper limit. All these represent risks and challenges to BIPS. Through WAMS technology research method in this project, the electrical power system function of monitoring, analysis, and control improved from the static state to the dynamic state. WAMS enhances data integration and real-time analysis capabilities, and can provide dispatchers with high quality real-time dynamic information and decision-making support information, enhance monitoring of auxiliary services in the electricity market, enable operators to improve the accuracy of power network analysis, thereby increasing power grid monitoring and operation, and improve the transmission capacity and reliability of the power grid operation [1].
基金Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPqGrant No.200682/2006-7)the Integrative Life Sciences PhD Program from Virginia Common-wealth University for financial support
文摘Molecular phylogenetic studies have become a major area of interest in plant systematics, and their impacts on historical biogeographic hypotheses are not to be disregarded. In Brazil, most historical biogeographic studies have relied on animal phylogenies, whereas plant biogeographic studies have largely lacked a phylogenetic component, having a limited utility for historical biogeography. That country, however, is of great importance for most biogeographic studies of lowland tropical South America, and it includes areas from a number of biogeographic regions of the continent. Important biogeographic reports have been published as part of phylogenetic studies, taxonomic monographs, and regional accounts for small areas or phytogeographic domains, but the available information is subsequently scattered and sometimes hard to find. In this paper we review some relevant angiosperm biogeographic studies in Brazil. Initially we briefly discuss the importance of other continents as source areas for the South American flora. Then we present a subdivision of Brazil into phytogeographic domains, and we cite studies that have explored the detection of biogeographic units (areas of endemism) and how they are historically related among those domains. Examples of plant taxa that could be used to test some biogeographic hypotheses are provided throughout, as well as taxa that exemplify several patterns of endemism and disjunction in the Brazilian angiosperm flora.
文摘Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial crests in pterodactyloids were sexually dimorphic and are thought to have evolved in adult males in response to female mate choice. However, the location of cranial crests in front of the center of gravity would create instability in the yaw axis during flight and may seem like a handicap. Vertically aligned webbed feet probably suppressed the yawing rotations and instability from the crest. Here we show that the crest functioned as a front rudder to make agile turn and mediate flight control. A computer simulation model suggests that Tapejara had a large excess of muscle power available above the power required for continuous flapping flight. It could easily takeoff from a perch, ground, or water surface and land safely on the ground. It was an excellent glider with a gliding angle close to 4~ and a cruising speed of 27 km/h. Tapejara could soar efficiently on the windward side of cliffs or circle on rising thermals over tropical waters for efficient long-distance flight. Various control surfaces in the wings of Tapejara analogous to the slat, aileron, elevator, fin, rudder, and horizontal stabilizer of an aircraft made pterodactyloids versatile flyers.
基金sponsored by Jilin Province Science and Technology Development Program,No.2009Z053
文摘BALB/c mice were intraperitoneally injected with 10, 5 or 2.5 mg/kg Brazil for 14 days after sciatic nerve injury. Results demonstrate that the spleen T/B lymphocyte stimulation index and serum circulating immune complex concentration were significantly reduced, and the morphology of the soleus muscle was restored in mice with sciatic nerve injury. These effects of Brazil were dose-dependent. Our experimental findings indicate that Brazil can regulate immune responses after nerve injury and promote sciatic nerve repair.
基金UFRJ(Federal University of Rio de Janeiro) and LMU(Ludwig Maximillians University in Munich,Germany) and several bilateral research projects
文摘The Venda Nova Pluton (VNP) is a zoned ring structure emplaced in the southern portion of the Neoproterozoic Araquai Belt, in Espirito Santo, Brazil. It is a slightly westward tilted cylinder-like intrusion, with an almost circular horizontal section. In the center of this structure, an off-centered gabbro-noritic core, surrounded by syeno-monzonitic rocks, intrudes an outer ring of charnockites and norite. These envelop the syeno-monzonitic and gabbro-noritic center, as a narrow discontinuous belt. While, in the core intrusion, mingling and mixing processes are widespread and well documented in the literature, in the outer ring, the norite and charnockite layers show predominantly homogeneous and isotropic internal structures. Nevertheless, smaller interaction zones between charnockites and norite denote a comparatively more restricted mingling process. The norite is a fine-grained rock with hypidio- morphic granular to intergranular texture. The charnockites are medium-grained and made up of: (a) orthopyroxene-tonalite, (h) orthopyroxene-quartz-diorite, and (c) orthopyroxene-granodiorite with hy- pidiomorphic granular to porphyritic textures. In all lithotypes both ortho- and clinopyroxene are replaced by hornblende and biotite. Two contrasting compositional sequences have been recognized, based on whole rock geochemistry: (1) a basic, with tholeiitic affinities (norite) and, (2) an intermediate, medium-K calc-alkalinc, comprising the charnockites. Estimated crystallization temperatures, which have been calculated from micro-probe analysis of pyroxenes, range from 915± 25 ℃ to 960 ± 50 ℃. Re-equilibration temperature (ihnenite-magnetite calibration) is around 600 ~ 50 ℃. This indicates oxygen fugacities four order of magnitude below the FMQ-buffer and a reduced environment. Coeval pressure conditions estimated from the Al-content in hornblende range from 5.5 ± 0.6 kbar. Data obtained for the norite point toward an evolution from the partial melting of an anhydrous tholeiitic mantle magma. The charnockites may correspond to the differentiation of a calc-alkaline parental magma. The later could be the hybrid product from the contamination and mixing between the anhydrous tholeiitic magma with other deeper crustal sources. Further the magmatic system evolved through frac- tionation of orthopyroxene, clinopyroxene, plagioclase and ilnlenite. Our results support the hypothesis for the evolution of the Venda Nova Pluton through a mantle-crust delamination process probably related to the collapse of the Araquai orogeny.
文摘This survey investigated the relationship between executive compensation and the financial performance of companies. It is hypothesized that a company can utilize its pay system to direct executives' efforts toward its strategic business objectives, thus contributing to higher levels of corporate financial performance. The survey data consisted of a secondary and non-probabilistic sample of 44 Brazilian industrial companies. In order to operationalize the independent remuneration variable, the authors used average monthly salary, average variable salary, and three indices that were created for this survey: benefits, career, and development. These indices measure the access to benefits, mechanisms for stimulating and supporting careers, and mechanisms to encourage education and professional development that companies offer to their directors, vice presidents, and chief executive officers (CEOs), who are referred to in this paper by the term "executive". The remuneration data are from fiscal year 2006. In order to operationalize the financial performance variable, two accounting indicators were used: sales growth and return on equity (ROE) for fiscal years 2006 and 2007. The size of the companies was used as a control variable. The results of a multiple regression analysis do not support the hypothesis that there is a positive and significant relationship between executive compensation and corporate financial performance.
文摘AIM: To determine hepatitis C virus (HCV) seropreva- lence and its genotypes, and to identify the factors associated with HCV infection. METHODS: This cross-sectional study, conducted in two prisons (one male and one female) in the State of Ser- gipe, Brazil, comprised 422 subjects. All of the prisoners underwent a rapid test for the detection of HCV antibod- ies. Patient~ with a positive result were tested for anti- HCV by enzyme linked immunosorbent assay and for HCV RNA by qualitative polymerase chain reaction (PCR). The virus genotype was defined in every serum sample that presented positive for PCR-HCV. In order to determine the factors independently associated with positive serol- ogy for HCV, multivariate logistic regression was used. RESULTS: HCV seroprevalence was 3.1%. Of the 13 subjects with positive anti-HCV, 11 had viremia confirmed by PCR. Of these, 90.9% had genotype 1. A total of 43 (10.2%) were injecting drug users, and HCV seroprevalence in this subgroup was 20.6%. The variable most strongly associated with positive serology for HCV was use of injecting drugs [odds ratio (OR), 23.3; 95% confidence interval (CI), 6.0-90.8]. Age over 30 years (OR, 5.5; 95%CI, 1.1-29.2), history of syphilis (OR, 9.8; 95%CI, 1.7-55.2) and history of household contact with HCV positive individual (OR, 14.1; 95%CI, 2.3-85.4) were also independently associated with HCV infection. CONCLUSION: Most of the HCV transmissions result from parenteral exposure. However, there is evidence to suggest a role for sex and household contact with an infected subject in virus transmission.
基金Project supported by the Space Application System of China Manned Space Programthe National Natural Science Foundation of China(Grant Nos.12072200 and 12002213)。
文摘We employ a Hall-effect magnetic sensor array to accurately track the trajectory of a single magnetic sphere,referred to as the“intruder,”within a three-dimensional vibro-fluidized granular bed to unravel the underlying physical mechanism governing the motion of the intruder.Within the acceleration range of 3.5 g≥Γ≥1.5 g,we find that,regardless of the intruder's initial position,it consistently reaches the same equilibrium depth when the vibration acceleration(Γ)and frequency(ω)are fixed.ForΓ≤2.5 g,the equilibrium position lies on the surface of the granular bed,while forΓ>2.5 g,it shifts below the surface.Additionally,intruders with different densities exhibit varying equilibrium depths,with higher density resulting in a deeper equilibrium position.To understand the mechanism behind the intruder's upward or downward motion,we measure its rising or sinking velocities under different vibration parameters.Our findings demonstrate that the rising velocity of the intruder,under varying vibration accelerations(Γ)and frequencies(ω),can be collapsed using the ratioΓ/ω,while the sinking velocity remains unaffected by the vibration strength.This confirms that the upward motion of the larger sphere,associated with the Brazil nut effect,primarily arises from the void-filling mechanism of the bed particles.Furthermore,our experiments reveal that the presence of convection within the bed particles has minimal impact on the motion of the intruder.
文摘New variola(NV)-mpox(monkeypox)-is a zoonosis caused by the mpox virus,which belongs to the genus Orthopoxvirus in the family Poxviridae.This disease,in the present year(2022),has caused several cases and deaths around the world,including Brazil[1].The group of poxviruses,in which the species that causes NV is included,consists of agents widely distributed in nature.Due to their considerably large size,they were among the first viruses to be microscopically visualized.The Poxviridae family is capable of infecting epithelial and connective tissue cells.Currently,such a viral family is classified as a genome lineage composed of doublestranded DNA,completely independent of the host nucleus[1].